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Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/spi-2.6
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Linus Torvalds
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57
Documentation/spi/butterfly
Normal file
57
Documentation/spi/butterfly
Normal file
|
|
@ -0,0 +1,57 @@
|
|||
spi_butterfly - parport-to-butterfly adapter driver
|
||||
===================================================
|
||||
|
||||
This is a hardware and software project that includes building and using
|
||||
a parallel port adapter cable, together with an "AVR Butterfly" to run
|
||||
firmware for user interfacing and/or sensors. A Butterfly is a $US20
|
||||
battery powered card with an AVR microcontroller and lots of goodies:
|
||||
sensors, LCD, flash, toggle stick, and more. You can use AVR-GCC to
|
||||
develop firmware for this, and flash it using this adapter cable.
|
||||
|
||||
You can make this adapter from an old printer cable and solder things
|
||||
directly to the Butterfly. Or (if you have the parts and skills) you
|
||||
can come up with something fancier, providing ciruit protection to the
|
||||
Butterfly and the printer port, or with a better power supply than two
|
||||
signal pins from the printer port.
|
||||
|
||||
|
||||
The first cable connections will hook Linux up to one SPI bus, with the
|
||||
AVR and a DataFlash chip; and to the AVR reset line. This is all you
|
||||
need to reflash the firmware, and the pins are the standard Atmel "ISP"
|
||||
connector pins (used also on non-Butterfly AVR boards).
|
||||
|
||||
Signal Butterfly Parport (DB-25)
|
||||
------ --------- ---------------
|
||||
SCK = J403.PB1/SCK = pin 2/D0
|
||||
RESET = J403.nRST = pin 3/D1
|
||||
VCC = J403.VCC_EXT = pin 8/D6
|
||||
MOSI = J403.PB2/MOSI = pin 9/D7
|
||||
MISO = J403.PB3/MISO = pin 11/S7,nBUSY
|
||||
GND = J403.GND = pin 23/GND
|
||||
|
||||
Then to let Linux master that bus to talk to the DataFlash chip, you must
|
||||
(a) flash new firmware that disables SPI (set PRR.2, and disable pullups
|
||||
by clearing PORTB.[0-3]); (b) configure the mtd_dataflash driver; and
|
||||
(c) cable in the chipselect.
|
||||
|
||||
Signal Butterfly Parport (DB-25)
|
||||
------ --------- ---------------
|
||||
VCC = J400.VCC_EXT = pin 7/D5
|
||||
SELECT = J400.PB0/nSS = pin 17/C3,nSELECT
|
||||
GND = J400.GND = pin 24/GND
|
||||
|
||||
The "USI" controller, using J405, can be used for a second SPI bus. That
|
||||
would let you talk to the AVR over SPI, running firmware that makes it act
|
||||
as an SPI slave, while letting either Linux or the AVR use the DataFlash.
|
||||
There are plenty of spare parport pins to wire this one up, such as:
|
||||
|
||||
Signal Butterfly Parport (DB-25)
|
||||
------ --------- ---------------
|
||||
SCK = J403.PE4/USCK = pin 5/D3
|
||||
MOSI = J403.PE5/DI = pin 6/D4
|
||||
MISO = J403.PE6/DO = pin 12/S5,nPAPEROUT
|
||||
GND = J403.GND = pin 22/GND
|
||||
|
||||
IRQ = J402.PF4 = pin 10/S6,ACK
|
||||
GND = J402.GND(P2) = pin 25/GND
|
||||
|
||||
457
Documentation/spi/spi-summary
Normal file
457
Documentation/spi/spi-summary
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|
|
@ -0,0 +1,457 @@
|
|||
Overview of Linux kernel SPI support
|
||||
====================================
|
||||
|
||||
02-Dec-2005
|
||||
|
||||
What is SPI?
|
||||
------------
|
||||
The "Serial Peripheral Interface" (SPI) is a synchronous four wire serial
|
||||
link used to connect microcontrollers to sensors, memory, and peripherals.
|
||||
|
||||
The three signal wires hold a clock (SCLK, often on the order of 10 MHz),
|
||||
and parallel data lines with "Master Out, Slave In" (MOSI) or "Master In,
|
||||
Slave Out" (MISO) signals. (Other names are also used.) There are four
|
||||
clocking modes through which data is exchanged; mode-0 and mode-3 are most
|
||||
commonly used. Each clock cycle shifts data out and data in; the clock
|
||||
doesn't cycle except when there is data to shift.
|
||||
|
||||
SPI masters may use a "chip select" line to activate a given SPI slave
|
||||
device, so those three signal wires may be connected to several chips
|
||||
in parallel. All SPI slaves support chipselects. Some devices have
|
||||
other signals, often including an interrupt to the master.
|
||||
|
||||
Unlike serial busses like USB or SMBUS, even low level protocols for
|
||||
SPI slave functions are usually not interoperable between vendors
|
||||
(except for cases like SPI memory chips).
|
||||
|
||||
- SPI may be used for request/response style device protocols, as with
|
||||
touchscreen sensors and memory chips.
|
||||
|
||||
- It may also be used to stream data in either direction (half duplex),
|
||||
or both of them at the same time (full duplex).
|
||||
|
||||
- Some devices may use eight bit words. Others may different word
|
||||
lengths, such as streams of 12-bit or 20-bit digital samples.
|
||||
|
||||
In the same way, SPI slaves will only rarely support any kind of automatic
|
||||
discovery/enumeration protocol. The tree of slave devices accessible from
|
||||
a given SPI master will normally be set up manually, with configuration
|
||||
tables.
|
||||
|
||||
SPI is only one of the names used by such four-wire protocols, and
|
||||
most controllers have no problem handling "MicroWire" (think of it as
|
||||
half-duplex SPI, for request/response protocols), SSP ("Synchronous
|
||||
Serial Protocol"), PSP ("Programmable Serial Protocol"), and other
|
||||
related protocols.
|
||||
|
||||
Microcontrollers often support both master and slave sides of the SPI
|
||||
protocol. This document (and Linux) currently only supports the master
|
||||
side of SPI interactions.
|
||||
|
||||
|
||||
Who uses it? On what kinds of systems?
|
||||
---------------------------------------
|
||||
Linux developers using SPI are probably writing device drivers for embedded
|
||||
systems boards. SPI is used to control external chips, and it is also a
|
||||
protocol supported by every MMC or SD memory card. (The older "DataFlash"
|
||||
cards, predating MMC cards but using the same connectors and card shape,
|
||||
support only SPI.) Some PC hardware uses SPI flash for BIOS code.
|
||||
|
||||
SPI slave chips range from digital/analog converters used for analog
|
||||
sensors and codecs, to memory, to peripherals like USB controllers
|
||||
or Ethernet adapters; and more.
|
||||
|
||||
Most systems using SPI will integrate a few devices on a mainboard.
|
||||
Some provide SPI links on expansion connectors; in cases where no
|
||||
dedicated SPI controller exists, GPIO pins can be used to create a
|
||||
low speed "bitbanging" adapter. Very few systems will "hotplug" an SPI
|
||||
controller; the reasons to use SPI focus on low cost and simple operation,
|
||||
and if dynamic reconfiguration is important, USB will often be a more
|
||||
appropriate low-pincount peripheral bus.
|
||||
|
||||
Many microcontrollers that can run Linux integrate one or more I/O
|
||||
interfaces with SPI modes. Given SPI support, they could use MMC or SD
|
||||
cards without needing a special purpose MMC/SD/SDIO controller.
|
||||
|
||||
|
||||
How do these driver programming interfaces work?
|
||||
------------------------------------------------
|
||||
The <linux/spi/spi.h> header file includes kerneldoc, as does the
|
||||
main source code, and you should certainly read that. This is just
|
||||
an overview, so you get the big picture before the details.
|
||||
|
||||
SPI requests always go into I/O queues. Requests for a given SPI device
|
||||
are always executed in FIFO order, and complete asynchronously through
|
||||
completion callbacks. There are also some simple synchronous wrappers
|
||||
for those calls, including ones for common transaction types like writing
|
||||
a command and then reading its response.
|
||||
|
||||
There are two types of SPI driver, here called:
|
||||
|
||||
Controller drivers ... these are often built in to System-On-Chip
|
||||
processors, and often support both Master and Slave roles.
|
||||
These drivers touch hardware registers and may use DMA.
|
||||
Or they can be PIO bitbangers, needing just GPIO pins.
|
||||
|
||||
Protocol drivers ... these pass messages through the controller
|
||||
driver to communicate with a Slave or Master device on the
|
||||
other side of an SPI link.
|
||||
|
||||
So for example one protocol driver might talk to the MTD layer to export
|
||||
data to filesystems stored on SPI flash like DataFlash; and others might
|
||||
control audio interfaces, present touchscreen sensors as input interfaces,
|
||||
or monitor temperature and voltage levels during industrial processing.
|
||||
And those might all be sharing the same controller driver.
|
||||
|
||||
A "struct spi_device" encapsulates the master-side interface between
|
||||
those two types of driver. At this writing, Linux has no slave side
|
||||
programming interface.
|
||||
|
||||
There is a minimal core of SPI programming interfaces, focussing on
|
||||
using driver model to connect controller and protocol drivers using
|
||||
device tables provided by board specific initialization code. SPI
|
||||
shows up in sysfs in several locations:
|
||||
|
||||
/sys/devices/.../CTLR/spiB.C ... spi_device for on bus "B",
|
||||
chipselect C, accessed through CTLR.
|
||||
|
||||
/sys/devices/.../CTLR/spiB.C/modalias ... identifies the driver
|
||||
that should be used with this device (for hotplug/coldplug)
|
||||
|
||||
/sys/bus/spi/devices/spiB.C ... symlink to the physical
|
||||
spiB-C device
|
||||
|
||||
/sys/bus/spi/drivers/D ... driver for one or more spi*.* devices
|
||||
|
||||
/sys/class/spi_master/spiB ... class device for the controller
|
||||
managing bus "B". All the spiB.* devices share the same
|
||||
physical SPI bus segment, with SCLK, MOSI, and MISO.
|
||||
|
||||
|
||||
How does board-specific init code declare SPI devices?
|
||||
------------------------------------------------------
|
||||
Linux needs several kinds of information to properly configure SPI devices.
|
||||
That information is normally provided by board-specific code, even for
|
||||
chips that do support some of automated discovery/enumeration.
|
||||
|
||||
DECLARE CONTROLLERS
|
||||
|
||||
The first kind of information is a list of what SPI controllers exist.
|
||||
For System-on-Chip (SOC) based boards, these will usually be platform
|
||||
devices, and the controller may need some platform_data in order to
|
||||
operate properly. The "struct platform_device" will include resources
|
||||
like the physical address of the controller's first register and its IRQ.
|
||||
|
||||
Platforms will often abstract the "register SPI controller" operation,
|
||||
maybe coupling it with code to initialize pin configurations, so that
|
||||
the arch/.../mach-*/board-*.c files for several boards can all share the
|
||||
same basic controller setup code. This is because most SOCs have several
|
||||
SPI-capable controllers, and only the ones actually usable on a given
|
||||
board should normally be set up and registered.
|
||||
|
||||
So for example arch/.../mach-*/board-*.c files might have code like:
|
||||
|
||||
#include <asm/arch/spi.h> /* for mysoc_spi_data */
|
||||
|
||||
/* if your mach-* infrastructure doesn't support kernels that can
|
||||
* run on multiple boards, pdata wouldn't benefit from "__init".
|
||||
*/
|
||||
static struct mysoc_spi_data __init pdata = { ... };
|
||||
|
||||
static __init board_init(void)
|
||||
{
|
||||
...
|
||||
/* this board only uses SPI controller #2 */
|
||||
mysoc_register_spi(2, &pdata);
|
||||
...
|
||||
}
|
||||
|
||||
And SOC-specific utility code might look something like:
|
||||
|
||||
#include <asm/arch/spi.h>
|
||||
|
||||
static struct platform_device spi2 = { ... };
|
||||
|
||||
void mysoc_register_spi(unsigned n, struct mysoc_spi_data *pdata)
|
||||
{
|
||||
struct mysoc_spi_data *pdata2;
|
||||
|
||||
pdata2 = kmalloc(sizeof *pdata2, GFP_KERNEL);
|
||||
*pdata2 = pdata;
|
||||
...
|
||||
if (n == 2) {
|
||||
spi2->dev.platform_data = pdata2;
|
||||
register_platform_device(&spi2);
|
||||
|
||||
/* also: set up pin modes so the spi2 signals are
|
||||
* visible on the relevant pins ... bootloaders on
|
||||
* production boards may already have done this, but
|
||||
* developer boards will often need Linux to do it.
|
||||
*/
|
||||
}
|
||||
...
|
||||
}
|
||||
|
||||
Notice how the platform_data for boards may be different, even if the
|
||||
same SOC controller is used. For example, on one board SPI might use
|
||||
an external clock, where another derives the SPI clock from current
|
||||
settings of some master clock.
|
||||
|
||||
|
||||
DECLARE SLAVE DEVICES
|
||||
|
||||
The second kind of information is a list of what SPI slave devices exist
|
||||
on the target board, often with some board-specific data needed for the
|
||||
driver to work correctly.
|
||||
|
||||
Normally your arch/.../mach-*/board-*.c files would provide a small table
|
||||
listing the SPI devices on each board. (This would typically be only a
|
||||
small handful.) That might look like:
|
||||
|
||||
static struct ads7846_platform_data ads_info = {
|
||||
.vref_delay_usecs = 100,
|
||||
.x_plate_ohms = 580,
|
||||
.y_plate_ohms = 410,
|
||||
};
|
||||
|
||||
static struct spi_board_info spi_board_info[] __initdata = {
|
||||
{
|
||||
.modalias = "ads7846",
|
||||
.platform_data = &ads_info,
|
||||
.mode = SPI_MODE_0,
|
||||
.irq = GPIO_IRQ(31),
|
||||
.max_speed_hz = 120000 /* max sample rate at 3V */ * 16,
|
||||
.bus_num = 1,
|
||||
.chip_select = 0,
|
||||
},
|
||||
};
|
||||
|
||||
Again, notice how board-specific information is provided; each chip may need
|
||||
several types. This example shows generic constraints like the fastest SPI
|
||||
clock to allow (a function of board voltage in this case) or how an IRQ pin
|
||||
is wired, plus chip-specific constraints like an important delay that's
|
||||
changed by the capacitance at one pin.
|
||||
|
||||
(There's also "controller_data", information that may be useful to the
|
||||
controller driver. An example would be peripheral-specific DMA tuning
|
||||
data or chipselect callbacks. This is stored in spi_device later.)
|
||||
|
||||
The board_info should provide enough information to let the system work
|
||||
without the chip's driver being loaded. The most troublesome aspect of
|
||||
that is likely the SPI_CS_HIGH bit in the spi_device.mode field, since
|
||||
sharing a bus with a device that interprets chipselect "backwards" is
|
||||
not possible.
|
||||
|
||||
Then your board initialization code would register that table with the SPI
|
||||
infrastructure, so that it's available later when the SPI master controller
|
||||
driver is registered:
|
||||
|
||||
spi_register_board_info(spi_board_info, ARRAY_SIZE(spi_board_info));
|
||||
|
||||
Like with other static board-specific setup, you won't unregister those.
|
||||
|
||||
The widely used "card" style computers bundle memory, cpu, and little else
|
||||
onto a card that's maybe just thirty square centimeters. On such systems,
|
||||
your arch/.../mach-.../board-*.c file would primarily provide information
|
||||
about the devices on the mainboard into which such a card is plugged. That
|
||||
certainly includes SPI devices hooked up through the card connectors!
|
||||
|
||||
|
||||
NON-STATIC CONFIGURATIONS
|
||||
|
||||
Developer boards often play by different rules than product boards, and one
|
||||
example is the potential need to hotplug SPI devices and/or controllers.
|
||||
|
||||
For those cases you might need to use use spi_busnum_to_master() to look
|
||||
up the spi bus master, and will likely need spi_new_device() to provide the
|
||||
board info based on the board that was hotplugged. Of course, you'd later
|
||||
call at least spi_unregister_device() when that board is removed.
|
||||
|
||||
When Linux includes support for MMC/SD/SDIO/DataFlash cards through SPI, those
|
||||
configurations will also be dynamic. Fortunately, those devices all support
|
||||
basic device identification probes, so that support should hotplug normally.
|
||||
|
||||
|
||||
How do I write an "SPI Protocol Driver"?
|
||||
----------------------------------------
|
||||
All SPI drivers are currently kernel drivers. A userspace driver API
|
||||
would just be another kernel driver, probably offering some lowlevel
|
||||
access through aio_read(), aio_write(), and ioctl() calls and using the
|
||||
standard userspace sysfs mechanisms to bind to a given SPI device.
|
||||
|
||||
SPI protocol drivers somewhat resemble platform device drivers:
|
||||
|
||||
static struct spi_driver CHIP_driver = {
|
||||
.driver = {
|
||||
.name = "CHIP",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
|
||||
.probe = CHIP_probe,
|
||||
.remove = __devexit_p(CHIP_remove),
|
||||
.suspend = CHIP_suspend,
|
||||
.resume = CHIP_resume,
|
||||
};
|
||||
|
||||
The driver core will autmatically attempt to bind this driver to any SPI
|
||||
device whose board_info gave a modalias of "CHIP". Your probe() code
|
||||
might look like this unless you're creating a class_device:
|
||||
|
||||
static int __devinit CHIP_probe(struct spi_device *spi)
|
||||
{
|
||||
struct CHIP *chip;
|
||||
struct CHIP_platform_data *pdata;
|
||||
|
||||
/* assuming the driver requires board-specific data: */
|
||||
pdata = &spi->dev.platform_data;
|
||||
if (!pdata)
|
||||
return -ENODEV;
|
||||
|
||||
/* get memory for driver's per-chip state */
|
||||
chip = kzalloc(sizeof *chip, GFP_KERNEL);
|
||||
if (!chip)
|
||||
return -ENOMEM;
|
||||
dev_set_drvdata(&spi->dev, chip);
|
||||
|
||||
... etc
|
||||
return 0;
|
||||
}
|
||||
|
||||
As soon as it enters probe(), the driver may issue I/O requests to
|
||||
the SPI device using "struct spi_message". When remove() returns,
|
||||
the driver guarantees that it won't submit any more such messages.
|
||||
|
||||
- An spi_message is a sequence of of protocol operations, executed
|
||||
as one atomic sequence. SPI driver controls include:
|
||||
|
||||
+ when bidirectional reads and writes start ... by how its
|
||||
sequence of spi_transfer requests is arranged;
|
||||
|
||||
+ optionally defining short delays after transfers ... using
|
||||
the spi_transfer.delay_usecs setting;
|
||||
|
||||
+ whether the chipselect becomes inactive after a transfer and
|
||||
any delay ... by using the spi_transfer.cs_change flag;
|
||||
|
||||
+ hinting whether the next message is likely to go to this same
|
||||
device ... using the spi_transfer.cs_change flag on the last
|
||||
transfer in that atomic group, and potentially saving costs
|
||||
for chip deselect and select operations.
|
||||
|
||||
- Follow standard kernel rules, and provide DMA-safe buffers in
|
||||
your messages. That way controller drivers using DMA aren't forced
|
||||
to make extra copies unless the hardware requires it (e.g. working
|
||||
around hardware errata that force the use of bounce buffering).
|
||||
|
||||
If standard dma_map_single() handling of these buffers is inappropriate,
|
||||
you can use spi_message.is_dma_mapped to tell the controller driver
|
||||
that you've already provided the relevant DMA addresses.
|
||||
|
||||
- The basic I/O primitive is spi_async(). Async requests may be
|
||||
issued in any context (irq handler, task, etc) and completion
|
||||
is reported using a callback provided with the message.
|
||||
After any detected error, the chip is deselected and processing
|
||||
of that spi_message is aborted.
|
||||
|
||||
- There are also synchronous wrappers like spi_sync(), and wrappers
|
||||
like spi_read(), spi_write(), and spi_write_then_read(). These
|
||||
may be issued only in contexts that may sleep, and they're all
|
||||
clean (and small, and "optional") layers over spi_async().
|
||||
|
||||
- The spi_write_then_read() call, and convenience wrappers around
|
||||
it, should only be used with small amounts of data where the
|
||||
cost of an extra copy may be ignored. It's designed to support
|
||||
common RPC-style requests, such as writing an eight bit command
|
||||
and reading a sixteen bit response -- spi_w8r16() being one its
|
||||
wrappers, doing exactly that.
|
||||
|
||||
Some drivers may need to modify spi_device characteristics like the
|
||||
transfer mode, wordsize, or clock rate. This is done with spi_setup(),
|
||||
which would normally be called from probe() before the first I/O is
|
||||
done to the device.
|
||||
|
||||
While "spi_device" would be the bottom boundary of the driver, the
|
||||
upper boundaries might include sysfs (especially for sensor readings),
|
||||
the input layer, ALSA, networking, MTD, the character device framework,
|
||||
or other Linux subsystems.
|
||||
|
||||
Note that there are two types of memory your driver must manage as part
|
||||
of interacting with SPI devices.
|
||||
|
||||
- I/O buffers use the usual Linux rules, and must be DMA-safe.
|
||||
You'd normally allocate them from the heap or free page pool.
|
||||
Don't use the stack, or anything that's declared "static".
|
||||
|
||||
- The spi_message and spi_transfer metadata used to glue those
|
||||
I/O buffers into a group of protocol transactions. These can
|
||||
be allocated anywhere it's convenient, including as part of
|
||||
other allocate-once driver data structures. Zero-init these.
|
||||
|
||||
If you like, spi_message_alloc() and spi_message_free() convenience
|
||||
routines are available to allocate and zero-initialize an spi_message
|
||||
with several transfers.
|
||||
|
||||
|
||||
How do I write an "SPI Master Controller Driver"?
|
||||
-------------------------------------------------
|
||||
An SPI controller will probably be registered on the platform_bus; write
|
||||
a driver to bind to the device, whichever bus is involved.
|
||||
|
||||
The main task of this type of driver is to provide an "spi_master".
|
||||
Use spi_alloc_master() to allocate the master, and class_get_devdata()
|
||||
to get the driver-private data allocated for that device.
|
||||
|
||||
struct spi_master *master;
|
||||
struct CONTROLLER *c;
|
||||
|
||||
master = spi_alloc_master(dev, sizeof *c);
|
||||
if (!master)
|
||||
return -ENODEV;
|
||||
|
||||
c = class_get_devdata(&master->cdev);
|
||||
|
||||
The driver will initialize the fields of that spi_master, including the
|
||||
bus number (maybe the same as the platform device ID) and three methods
|
||||
used to interact with the SPI core and SPI protocol drivers. It will
|
||||
also initialize its own internal state.
|
||||
|
||||
master->setup(struct spi_device *spi)
|
||||
This sets up the device clock rate, SPI mode, and word sizes.
|
||||
Drivers may change the defaults provided by board_info, and then
|
||||
call spi_setup(spi) to invoke this routine. It may sleep.
|
||||
|
||||
master->transfer(struct spi_device *spi, struct spi_message *message)
|
||||
This must not sleep. Its responsibility is arrange that the
|
||||
transfer happens and its complete() callback is issued; the two
|
||||
will normally happen later, after other transfers complete.
|
||||
|
||||
master->cleanup(struct spi_device *spi)
|
||||
Your controller driver may use spi_device.controller_state to hold
|
||||
state it dynamically associates with that device. If you do that,
|
||||
be sure to provide the cleanup() method to free that state.
|
||||
|
||||
The bulk of the driver will be managing the I/O queue fed by transfer().
|
||||
|
||||
That queue could be purely conceptual. For example, a driver used only
|
||||
for low-frequency sensor acess might be fine using synchronous PIO.
|
||||
|
||||
But the queue will probably be very real, using message->queue, PIO,
|
||||
often DMA (especially if the root filesystem is in SPI flash), and
|
||||
execution contexts like IRQ handlers, tasklets, or workqueues (such
|
||||
as keventd). Your driver can be as fancy, or as simple, as you need.
|
||||
|
||||
|
||||
THANKS TO
|
||||
---------
|
||||
Contributors to Linux-SPI discussions include (in alphabetical order,
|
||||
by last name):
|
||||
|
||||
David Brownell
|
||||
Russell King
|
||||
Dmitry Pervushin
|
||||
Stephen Street
|
||||
Mark Underwood
|
||||
Andrew Victor
|
||||
Vitaly Wool
|
||||
|
||||
|
|
@ -729,6 +729,8 @@ source "drivers/char/Kconfig"
|
|||
|
||||
source "drivers/i2c/Kconfig"
|
||||
|
||||
source "drivers/spi/Kconfig"
|
||||
|
||||
source "drivers/hwmon/Kconfig"
|
||||
|
||||
#source "drivers/l3/Kconfig"
|
||||
|
|
|
|||
|
|
@ -44,6 +44,8 @@ source "drivers/char/Kconfig"
|
|||
|
||||
source "drivers/i2c/Kconfig"
|
||||
|
||||
source "drivers/spi/Kconfig"
|
||||
|
||||
source "drivers/w1/Kconfig"
|
||||
|
||||
source "drivers/hwmon/Kconfig"
|
||||
|
|
|
|||
|
|
@ -41,6 +41,7 @@ obj-$(CONFIG_FUSION) += message/
|
|||
obj-$(CONFIG_IEEE1394) += ieee1394/
|
||||
obj-y += cdrom/
|
||||
obj-$(CONFIG_MTD) += mtd/
|
||||
obj-$(CONFIG_SPI) += spi/
|
||||
obj-$(CONFIG_PCCARD) += pcmcia/
|
||||
obj-$(CONFIG_DIO) += dio/
|
||||
obj-$(CONFIG_SBUS) += sbus/
|
||||
|
|
|
|||
|
|
@ -11,6 +11,19 @@ menuconfig INPUT_TOUCHSCREEN
|
|||
|
||||
if INPUT_TOUCHSCREEN
|
||||
|
||||
config TOUCHSCREEN_ADS7846
|
||||
tristate "ADS 7846 based touchscreens"
|
||||
depends on SPI_MASTER
|
||||
help
|
||||
Say Y here if you have a touchscreen interface using the
|
||||
ADS7846 controller, and your board-specific initialization
|
||||
code includes that in its table of SPI devices.
|
||||
|
||||
If unsure, say N (but it's safe to say "Y").
|
||||
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called ads7846.
|
||||
|
||||
config TOUCHSCREEN_BITSY
|
||||
tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
|
||||
depends on SA1100_BITSY
|
||||
|
|
|
|||
|
|
@ -4,6 +4,7 @@
|
|||
|
||||
# Each configuration option enables a list of files.
|
||||
|
||||
obj-$(CONFIG_TOUCHSCREEN_ADS7846) += ads7846.o
|
||||
obj-$(CONFIG_TOUCHSCREEN_BITSY) += h3600_ts_input.o
|
||||
obj-$(CONFIG_TOUCHSCREEN_CORGI) += corgi_ts.o
|
||||
obj-$(CONFIG_TOUCHSCREEN_GUNZE) += gunze.o
|
||||
|
|
|
|||
625
drivers/input/touchscreen/ads7846.c
Normal file
625
drivers/input/touchscreen/ads7846.c
Normal file
|
|
@ -0,0 +1,625 @@
|
|||
/*
|
||||
* ADS7846 based touchscreen and sensor driver
|
||||
*
|
||||
* Copyright (c) 2005 David Brownell
|
||||
*
|
||||
* Using code from:
|
||||
* - corgi_ts.c
|
||||
* Copyright (C) 2004-2005 Richard Purdie
|
||||
* - omap_ts.[hc], ads7846.h, ts_osk.c
|
||||
* Copyright (C) 2002 MontaVista Software
|
||||
* Copyright (C) 2004 Texas Instruments
|
||||
* Copyright (C) 2005 Dirk Behme
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*/
|
||||
#include <linux/device.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/input.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/spi/ads7846.h>
|
||||
|
||||
#ifdef CONFIG_ARM
|
||||
#include <asm/mach-types.h>
|
||||
#ifdef CONFIG_ARCH_OMAP
|
||||
#include <asm/arch/gpio.h>
|
||||
#endif
|
||||
|
||||
#else
|
||||
#define set_irq_type(irq,type) do{}while(0)
|
||||
#endif
|
||||
|
||||
|
||||
/*
|
||||
* This code has been lightly tested on an ads7846.
|
||||
* Support for ads7843 and ads7845 has only been stubbed in.
|
||||
*
|
||||
* Not yet done: investigate the values reported. Are x/y/pressure
|
||||
* event values sane enough for X11? How accurate are the temperature
|
||||
* and voltage readings? (System-specific calibration should support
|
||||
* accuracy of 0.3 degrees C; otherwise it's 2.0 degrees.)
|
||||
*
|
||||
* app note sbaa036 talks in more detail about accurate sampling...
|
||||
* that ought to help in situations like LCDs inducing noise (which
|
||||
* can also be helped by using synch signals) and more generally.
|
||||
*/
|
||||
|
||||
#define TS_POLL_PERIOD msecs_to_jiffies(10)
|
||||
|
||||
struct ts_event {
|
||||
/* For portability, we can't read 12 bit values using SPI (which
|
||||
* would make the controller deliver them as native byteorder u16
|
||||
* with msbs zeroed). Instead, we read them as two 8-byte values,
|
||||
* which need byteswapping then range adjustment.
|
||||
*/
|
||||
__be16 x;
|
||||
__be16 y;
|
||||
__be16 z1, z2;
|
||||
};
|
||||
|
||||
struct ads7846 {
|
||||
struct input_dev input;
|
||||
char phys[32];
|
||||
|
||||
struct spi_device *spi;
|
||||
u16 model;
|
||||
u16 vref_delay_usecs;
|
||||
u16 x_plate_ohms;
|
||||
|
||||
struct ts_event tc;
|
||||
|
||||
struct spi_transfer xfer[8];
|
||||
struct spi_message msg;
|
||||
|
||||
spinlock_t lock;
|
||||
struct timer_list timer; /* P: lock */
|
||||
unsigned pendown:1; /* P: lock */
|
||||
unsigned pending:1; /* P: lock */
|
||||
// FIXME remove "irq_disabled"
|
||||
unsigned irq_disabled:1; /* P: lock */
|
||||
};
|
||||
|
||||
/* leave chip selected when we're done, for quicker re-select? */
|
||||
#if 0
|
||||
#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
|
||||
#else
|
||||
#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
|
||||
#endif
|
||||
|
||||
/*--------------------------------------------------------------------------*/
|
||||
|
||||
/* The ADS7846 has touchscreen and other sensors.
|
||||
* Earlier ads784x chips are somewhat compatible.
|
||||
*/
|
||||
#define ADS_START (1 << 7)
|
||||
#define ADS_A2A1A0_d_y (1 << 4) /* differential */
|
||||
#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
|
||||
#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
|
||||
#define ADS_A2A1A0_d_x (5 << 4) /* differential */
|
||||
#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
|
||||
#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
|
||||
#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
|
||||
#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
|
||||
#define ADS_8_BIT (1 << 3)
|
||||
#define ADS_12_BIT (0 << 3)
|
||||
#define ADS_SER (1 << 2) /* non-differential */
|
||||
#define ADS_DFR (0 << 2) /* differential */
|
||||
#define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */
|
||||
#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
|
||||
#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
|
||||
#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
|
||||
|
||||
#define MAX_12BIT ((1<<12)-1)
|
||||
|
||||
/* leave ADC powered up (disables penirq) between differential samples */
|
||||
#define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
|
||||
| ADS_12_BIT | ADS_DFR)
|
||||
|
||||
static const u8 read_y = READ_12BIT_DFR(y) | ADS_PD10_ADC_ON;
|
||||
static const u8 read_z1 = READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON;
|
||||
static const u8 read_z2 = READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON;
|
||||
static const u8 read_x = READ_12BIT_DFR(x) | ADS_PD10_PDOWN; /* LAST */
|
||||
|
||||
/* single-ended samples need to first power up reference voltage;
|
||||
* we leave both ADC and VREF powered
|
||||
*/
|
||||
#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
|
||||
| ADS_12_BIT | ADS_SER)
|
||||
|
||||
static const u8 ref_on = READ_12BIT_DFR(x) | ADS_PD10_ALL_ON;
|
||||
static const u8 ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN;
|
||||
|
||||
/*--------------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* Non-touchscreen sensors only use single-ended conversions.
|
||||
*/
|
||||
|
||||
struct ser_req {
|
||||
u8 command;
|
||||
u16 scratch;
|
||||
__be16 sample;
|
||||
struct spi_message msg;
|
||||
struct spi_transfer xfer[6];
|
||||
};
|
||||
|
||||
static int ads7846_read12_ser(struct device *dev, unsigned command)
|
||||
{
|
||||
struct spi_device *spi = to_spi_device(dev);
|
||||
struct ads7846 *ts = dev_get_drvdata(dev);
|
||||
struct ser_req *req = kzalloc(sizeof *req, SLAB_KERNEL);
|
||||
int status;
|
||||
int sample;
|
||||
int i;
|
||||
|
||||
if (!req)
|
||||
return -ENOMEM;
|
||||
|
||||
INIT_LIST_HEAD(&req->msg.transfers);
|
||||
|
||||
/* activate reference, so it has time to settle; */
|
||||
req->xfer[0].tx_buf = &ref_on;
|
||||
req->xfer[0].len = 1;
|
||||
req->xfer[1].rx_buf = &req->scratch;
|
||||
req->xfer[1].len = 2;
|
||||
|
||||
/*
|
||||
* for external VREF, 0 usec (and assume it's always on);
|
||||
* for 1uF, use 800 usec;
|
||||
* no cap, 100 usec.
|
||||
*/
|
||||
req->xfer[1].delay_usecs = ts->vref_delay_usecs;
|
||||
|
||||
/* take sample */
|
||||
req->command = (u8) command;
|
||||
req->xfer[2].tx_buf = &req->command;
|
||||
req->xfer[2].len = 1;
|
||||
req->xfer[3].rx_buf = &req->sample;
|
||||
req->xfer[3].len = 2;
|
||||
|
||||
/* REVISIT: take a few more samples, and compare ... */
|
||||
|
||||
/* turn off reference */
|
||||
req->xfer[4].tx_buf = &ref_off;
|
||||
req->xfer[4].len = 1;
|
||||
req->xfer[5].rx_buf = &req->scratch;
|
||||
req->xfer[5].len = 2;
|
||||
|
||||
CS_CHANGE(req->xfer[5]);
|
||||
|
||||
/* group all the transfers together, so we can't interfere with
|
||||
* reading touchscreen state; disable penirq while sampling
|
||||
*/
|
||||
for (i = 0; i < 6; i++)
|
||||
spi_message_add_tail(&req->xfer[i], &req->msg);
|
||||
|
||||
disable_irq(spi->irq);
|
||||
status = spi_sync(spi, &req->msg);
|
||||
enable_irq(spi->irq);
|
||||
|
||||
if (req->msg.status)
|
||||
status = req->msg.status;
|
||||
sample = be16_to_cpu(req->sample);
|
||||
sample = sample >> 4;
|
||||
kfree(req);
|
||||
|
||||
return status ? status : sample;
|
||||
}
|
||||
|
||||
#define SHOW(name) static ssize_t \
|
||||
name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
|
||||
{ \
|
||||
ssize_t v = ads7846_read12_ser(dev, \
|
||||
READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
|
||||
if (v < 0) \
|
||||
return v; \
|
||||
return sprintf(buf, "%u\n", (unsigned) v); \
|
||||
} \
|
||||
static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
|
||||
|
||||
SHOW(temp0)
|
||||
SHOW(temp1)
|
||||
SHOW(vaux)
|
||||
SHOW(vbatt)
|
||||
|
||||
/*--------------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
|
||||
* to retrieve touchscreen status.
|
||||
*
|
||||
* The SPI transfer completion callback does the real work. It reports
|
||||
* touchscreen events and reactivates the timer (or IRQ) as appropriate.
|
||||
*/
|
||||
|
||||
static void ads7846_rx(void *ads)
|
||||
{
|
||||
struct ads7846 *ts = ads;
|
||||
unsigned Rt;
|
||||
unsigned sync = 0;
|
||||
u16 x, y, z1, z2;
|
||||
unsigned long flags;
|
||||
|
||||
/* adjust: 12 bit samples (left aligned), built from
|
||||
* two 8 bit values writen msb-first.
|
||||
*/
|
||||
x = be16_to_cpu(ts->tc.x) >> 4;
|
||||
y = be16_to_cpu(ts->tc.y) >> 4;
|
||||
z1 = be16_to_cpu(ts->tc.z1) >> 4;
|
||||
z2 = be16_to_cpu(ts->tc.z2) >> 4;
|
||||
|
||||
/* range filtering */
|
||||
if (x == MAX_12BIT)
|
||||
x = 0;
|
||||
|
||||
if (x && z1 && ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
|
||||
/* compute touch pressure resistance using equation #2 */
|
||||
Rt = z2;
|
||||
Rt -= z1;
|
||||
Rt *= x;
|
||||
Rt *= ts->x_plate_ohms;
|
||||
Rt /= z1;
|
||||
Rt = (Rt + 2047) >> 12;
|
||||
} else
|
||||
Rt = 0;
|
||||
|
||||
/* NOTE: "pendown" is inferred from pressure; we don't rely on
|
||||
* being able to check nPENIRQ status, or "friendly" trigger modes
|
||||
* (both-edges is much better than just-falling or low-level).
|
||||
*
|
||||
* REVISIT: some boards may require reading nPENIRQ; it's
|
||||
* needed on 7843. and 7845 reads pressure differently...
|
||||
*
|
||||
* REVISIT: the touchscreen might not be connected; this code
|
||||
* won't notice that, even if nPENIRQ never fires ...
|
||||
*/
|
||||
if (!ts->pendown && Rt != 0) {
|
||||
input_report_key(&ts->input, BTN_TOUCH, 1);
|
||||
sync = 1;
|
||||
} else if (ts->pendown && Rt == 0) {
|
||||
input_report_key(&ts->input, BTN_TOUCH, 0);
|
||||
sync = 1;
|
||||
}
|
||||
|
||||
if (Rt) {
|
||||
input_report_abs(&ts->input, ABS_X, x);
|
||||
input_report_abs(&ts->input, ABS_Y, y);
|
||||
input_report_abs(&ts->input, ABS_PRESSURE, Rt);
|
||||
sync = 1;
|
||||
}
|
||||
if (sync)
|
||||
input_sync(&ts->input);
|
||||
|
||||
#ifdef VERBOSE
|
||||
if (Rt || ts->pendown)
|
||||
pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
|
||||
x, y, Rt, Rt ? "" : " UP");
|
||||
#endif
|
||||
|
||||
/* don't retrigger while we're suspended */
|
||||
spin_lock_irqsave(&ts->lock, flags);
|
||||
|
||||
ts->pendown = (Rt != 0);
|
||||
ts->pending = 0;
|
||||
|
||||
if (ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
|
||||
if (ts->pendown)
|
||||
mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
|
||||
else if (ts->irq_disabled) {
|
||||
ts->irq_disabled = 0;
|
||||
enable_irq(ts->spi->irq);
|
||||
}
|
||||
}
|
||||
|
||||
spin_unlock_irqrestore(&ts->lock, flags);
|
||||
}
|
||||
|
||||
static void ads7846_timer(unsigned long handle)
|
||||
{
|
||||
struct ads7846 *ts = (void *)handle;
|
||||
int status = 0;
|
||||
unsigned long flags;
|
||||
|
||||
spin_lock_irqsave(&ts->lock, flags);
|
||||
if (!ts->pending) {
|
||||
ts->pending = 1;
|
||||
if (!ts->irq_disabled) {
|
||||
ts->irq_disabled = 1;
|
||||
disable_irq(ts->spi->irq);
|
||||
}
|
||||
status = spi_async(ts->spi, &ts->msg);
|
||||
if (status)
|
||||
dev_err(&ts->spi->dev, "spi_async --> %d\n",
|
||||
status);
|
||||
}
|
||||
spin_unlock_irqrestore(&ts->lock, flags);
|
||||
}
|
||||
|
||||
static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs)
|
||||
{
|
||||
ads7846_timer((unsigned long) handle);
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
/*--------------------------------------------------------------------------*/
|
||||
|
||||
static int
|
||||
ads7846_suspend(struct spi_device *spi, pm_message_t message)
|
||||
{
|
||||
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
||||
unsigned long flags;
|
||||
|
||||
spin_lock_irqsave(&ts->lock, flags);
|
||||
|
||||
spi->dev.power.power_state = message;
|
||||
|
||||
/* are we waiting for IRQ, or polling? */
|
||||
if (!ts->pendown) {
|
||||
if (!ts->irq_disabled) {
|
||||
ts->irq_disabled = 1;
|
||||
disable_irq(ts->spi->irq);
|
||||
}
|
||||
} else {
|
||||
/* polling; force a final SPI completion;
|
||||
* that will clean things up neatly
|
||||
*/
|
||||
if (!ts->pending)
|
||||
mod_timer(&ts->timer, jiffies);
|
||||
|
||||
while (ts->pendown || ts->pending) {
|
||||
spin_unlock_irqrestore(&ts->lock, flags);
|
||||
udelay(10);
|
||||
spin_lock_irqsave(&ts->lock, flags);
|
||||
}
|
||||
}
|
||||
|
||||
/* we know the chip's in lowpower mode since we always
|
||||
* leave it that way after every request
|
||||
*/
|
||||
|
||||
spin_unlock_irqrestore(&ts->lock, flags);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ads7846_resume(struct spi_device *spi)
|
||||
{
|
||||
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
||||
|
||||
ts->irq_disabled = 0;
|
||||
enable_irq(ts->spi->irq);
|
||||
spi->dev.power.power_state = PMSG_ON;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __devinit ads7846_probe(struct spi_device *spi)
|
||||
{
|
||||
struct ads7846 *ts;
|
||||
struct ads7846_platform_data *pdata = spi->dev.platform_data;
|
||||
struct spi_transfer *x;
|
||||
int i;
|
||||
|
||||
if (!spi->irq) {
|
||||
dev_dbg(&spi->dev, "no IRQ?\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
if (!pdata) {
|
||||
dev_dbg(&spi->dev, "no platform data?\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
/* don't exceed max specified sample rate */
|
||||
if (spi->max_speed_hz > (125000 * 16)) {
|
||||
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
|
||||
(spi->max_speed_hz/16)/1000);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* We'd set the wordsize to 12 bits ... except that some controllers
|
||||
* will then treat the 8 bit command words as 12 bits (and drop the
|
||||
* four MSBs of the 12 bit result). Result: inputs must be shifted
|
||||
* to discard the four garbage LSBs.
|
||||
*/
|
||||
|
||||
if (!(ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL)))
|
||||
return -ENOMEM;
|
||||
|
||||
dev_set_drvdata(&spi->dev, ts);
|
||||
|
||||
ts->spi = spi;
|
||||
spi->dev.power.power_state = PMSG_ON;
|
||||
|
||||
init_timer(&ts->timer);
|
||||
ts->timer.data = (unsigned long) ts;
|
||||
ts->timer.function = ads7846_timer;
|
||||
|
||||
ts->model = pdata->model ? : 7846;
|
||||
ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
|
||||
ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
|
||||
|
||||
init_input_dev(&ts->input);
|
||||
|
||||
ts->input.dev = &spi->dev;
|
||||
ts->input.name = "ADS784x Touchscreen";
|
||||
snprintf(ts->phys, sizeof ts->phys, "%s/input0", spi->dev.bus_id);
|
||||
ts->input.phys = ts->phys;
|
||||
|
||||
ts->input.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
|
||||
ts->input.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
|
||||
input_set_abs_params(&ts->input, ABS_X,
|
||||
pdata->x_min ? : 0,
|
||||
pdata->x_max ? : MAX_12BIT,
|
||||
0, 0);
|
||||
input_set_abs_params(&ts->input, ABS_Y,
|
||||
pdata->y_min ? : 0,
|
||||
pdata->y_max ? : MAX_12BIT,
|
||||
0, 0);
|
||||
input_set_abs_params(&ts->input, ABS_PRESSURE,
|
||||
pdata->pressure_min, pdata->pressure_max, 0, 0);
|
||||
|
||||
input_register_device(&ts->input);
|
||||
|
||||
/* set up the transfers to read touchscreen state; this assumes we
|
||||
* use formula #2 for pressure, not #3.
|
||||
*/
|
||||
x = ts->xfer;
|
||||
|
||||
/* y- still on; turn on only y+ (and ADC) */
|
||||
x->tx_buf = &read_y;
|
||||
x->len = 1;
|
||||
x++;
|
||||
x->rx_buf = &ts->tc.y;
|
||||
x->len = 2;
|
||||
x++;
|
||||
|
||||
/* turn y+ off, x- on; we'll use formula #2 */
|
||||
if (ts->model == 7846) {
|
||||
x->tx_buf = &read_z1;
|
||||
x->len = 1;
|
||||
x++;
|
||||
x->rx_buf = &ts->tc.z1;
|
||||
x->len = 2;
|
||||
x++;
|
||||
|
||||
x->tx_buf = &read_z2;
|
||||
x->len = 1;
|
||||
x++;
|
||||
x->rx_buf = &ts->tc.z2;
|
||||
x->len = 2;
|
||||
x++;
|
||||
}
|
||||
|
||||
/* turn y- off, x+ on, then leave in lowpower */
|
||||
x->tx_buf = &read_x;
|
||||
x->len = 1;
|
||||
x++;
|
||||
x->rx_buf = &ts->tc.x;
|
||||
x->len = 2;
|
||||
x++;
|
||||
|
||||
CS_CHANGE(x[-1]);
|
||||
|
||||
for (i = 0; i < x - ts->xfer; i++)
|
||||
spi_message_add_tail(&ts->xfer[i], &ts->msg);
|
||||
ts->msg.complete = ads7846_rx;
|
||||
ts->msg.context = ts;
|
||||
|
||||
if (request_irq(spi->irq, ads7846_irq, SA_SAMPLE_RANDOM,
|
||||
spi->dev.bus_id, ts)) {
|
||||
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
|
||||
input_unregister_device(&ts->input);
|
||||
kfree(ts);
|
||||
return -EBUSY;
|
||||
}
|
||||
set_irq_type(spi->irq, IRQT_FALLING);
|
||||
|
||||
dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
|
||||
|
||||
/* take a first sample, leaving nPENIRQ active; avoid
|
||||
* the touchscreen, in case it's not connected.
|
||||
*/
|
||||
(void) ads7846_read12_ser(&spi->dev,
|
||||
READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
|
||||
|
||||
/* ads7843/7845 don't have temperature sensors, and
|
||||
* use the other sensors a bit differently too
|
||||
*/
|
||||
if (ts->model == 7846) {
|
||||
device_create_file(&spi->dev, &dev_attr_temp0);
|
||||
device_create_file(&spi->dev, &dev_attr_temp1);
|
||||
}
|
||||
if (ts->model != 7845)
|
||||
device_create_file(&spi->dev, &dev_attr_vbatt);
|
||||
device_create_file(&spi->dev, &dev_attr_vaux);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __devexit ads7846_remove(struct spi_device *spi)
|
||||
{
|
||||
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
||||
|
||||
ads7846_suspend(spi, PMSG_SUSPEND);
|
||||
free_irq(ts->spi->irq, ts);
|
||||
if (ts->irq_disabled)
|
||||
enable_irq(ts->spi->irq);
|
||||
|
||||
if (ts->model == 7846) {
|
||||
device_remove_file(&spi->dev, &dev_attr_temp0);
|
||||
device_remove_file(&spi->dev, &dev_attr_temp1);
|
||||
}
|
||||
if (ts->model != 7845)
|
||||
device_remove_file(&spi->dev, &dev_attr_vbatt);
|
||||
device_remove_file(&spi->dev, &dev_attr_vaux);
|
||||
|
||||
input_unregister_device(&ts->input);
|
||||
kfree(ts);
|
||||
|
||||
dev_dbg(&spi->dev, "unregistered touchscreen\n");
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct spi_driver ads7846_driver = {
|
||||
.driver = {
|
||||
.name = "ads7846",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = ads7846_probe,
|
||||
.remove = __devexit_p(ads7846_remove),
|
||||
.suspend = ads7846_suspend,
|
||||
.resume = ads7846_resume,
|
||||
};
|
||||
|
||||
static int __init ads7846_init(void)
|
||||
{
|
||||
/* grr, board-specific init should stay out of drivers!! */
|
||||
|
||||
#ifdef CONFIG_ARCH_OMAP
|
||||
if (machine_is_omap_osk()) {
|
||||
/* GPIO4 = PENIRQ; GPIO6 = BUSY */
|
||||
omap_request_gpio(4);
|
||||
omap_set_gpio_direction(4, 1);
|
||||
omap_request_gpio(6);
|
||||
omap_set_gpio_direction(6, 1);
|
||||
}
|
||||
// also TI 1510 Innovator, bitbanging through FPGA
|
||||
// also Nokia 770
|
||||
// also Palm Tungsten T2
|
||||
#endif
|
||||
|
||||
// PXA:
|
||||
// also Dell Axim X50
|
||||
// also HP iPaq H191x/H192x/H415x/H435x
|
||||
// also Intel Lubbock (additional to UCB1400; as temperature sensor)
|
||||
// also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
|
||||
|
||||
// Atmel at91sam9261-EK uses ads7843
|
||||
|
||||
// also various AMD Au1x00 devel boards
|
||||
|
||||
return spi_register_driver(&ads7846_driver);
|
||||
}
|
||||
module_init(ads7846_init);
|
||||
|
||||
static void __exit ads7846_exit(void)
|
||||
{
|
||||
spi_unregister_driver(&ads7846_driver);
|
||||
|
||||
#ifdef CONFIG_ARCH_OMAP
|
||||
if (machine_is_omap_osk()) {
|
||||
omap_free_gpio(4);
|
||||
omap_free_gpio(6);
|
||||
}
|
||||
#endif
|
||||
|
||||
}
|
||||
module_exit(ads7846_exit);
|
||||
|
||||
MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
|
|
@ -47,6 +47,22 @@ config MTD_MS02NV
|
|||
accelerator. Say Y here if you have a DECstation 5000/2x0 or a
|
||||
DECsystem 5900 equipped with such a module.
|
||||
|
||||
config MTD_DATAFLASH
|
||||
tristate "Support for AT45xxx DataFlash"
|
||||
depends on MTD && SPI_MASTER && EXPERIMENTAL
|
||||
help
|
||||
This enables access to AT45xxx DataFlash chips, using SPI.
|
||||
Sometimes DataFlash chips are packaged inside MMC-format
|
||||
cards; at this writing, the MMC stack won't handle those.
|
||||
|
||||
config MTD_M25P80
|
||||
tristate "Support for M25 SPI Flash"
|
||||
depends on MTD && SPI_MASTER && EXPERIMENTAL
|
||||
help
|
||||
This enables access to ST M25P80 and similar SPI flash chips,
|
||||
used for program and data storage. Set up your spi devices
|
||||
with the right board-specific platform data.
|
||||
|
||||
config MTD_SLRAM
|
||||
tristate "Uncached system RAM"
|
||||
depends on MTD
|
||||
|
|
|
|||
|
|
@ -23,3 +23,5 @@ obj-$(CONFIG_MTD_MTDRAM) += mtdram.o
|
|||
obj-$(CONFIG_MTD_LART) += lart.o
|
||||
obj-$(CONFIG_MTD_BLKMTD) += blkmtd.o
|
||||
obj-$(CONFIG_MTD_BLOCK2MTD) += block2mtd.o
|
||||
obj-$(CONFIG_MTD_DATAFLASH) += mtd_dataflash.o
|
||||
obj-$(CONFIG_MTD_M25P80) += m25p80.o
|
||||
|
|
|
|||
582
drivers/mtd/devices/m25p80.c
Normal file
582
drivers/mtd/devices/m25p80.c
Normal file
|
|
@ -0,0 +1,582 @@
|
|||
/*
|
||||
* MTD SPI driver for ST M25Pxx flash chips
|
||||
*
|
||||
* Author: Mike Lavender, mike@steroidmicros.com
|
||||
*
|
||||
* Copyright (c) 2005, Intec Automation Inc.
|
||||
*
|
||||
* Some parts are based on lart.c by Abraham Van Der Merwe
|
||||
*
|
||||
* Cleaned up and generalized based on mtd_dataflash.c
|
||||
*
|
||||
* This code is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
*/
|
||||
|
||||
#include <linux/init.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/mtd/mtd.h>
|
||||
#include <linux/mtd/partitions.h>
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/spi/flash.h>
|
||||
|
||||
#include <asm/semaphore.h>
|
||||
|
||||
|
||||
/* NOTE: AT 25F and SST 25LF series are very similar,
|
||||
* but commands for sector erase and chip id differ...
|
||||
*/
|
||||
|
||||
#define FLASH_PAGESIZE 256
|
||||
|
||||
/* Flash opcodes. */
|
||||
#define OPCODE_WREN 6 /* Write enable */
|
||||
#define OPCODE_RDSR 5 /* Read status register */
|
||||
#define OPCODE_READ 3 /* Read data bytes */
|
||||
#define OPCODE_PP 2 /* Page program */
|
||||
#define OPCODE_SE 0xd8 /* Sector erase */
|
||||
#define OPCODE_RES 0xab /* Read Electronic Signature */
|
||||
#define OPCODE_RDID 0x9f /* Read JEDEC ID */
|
||||
|
||||
/* Status Register bits. */
|
||||
#define SR_WIP 1 /* Write in progress */
|
||||
#define SR_WEL 2 /* Write enable latch */
|
||||
#define SR_BP0 4 /* Block protect 0 */
|
||||
#define SR_BP1 8 /* Block protect 1 */
|
||||
#define SR_BP2 0x10 /* Block protect 2 */
|
||||
#define SR_SRWD 0x80 /* SR write protect */
|
||||
|
||||
/* Define max times to check status register before we give up. */
|
||||
#define MAX_READY_WAIT_COUNT 100000
|
||||
|
||||
|
||||
#ifdef CONFIG_MTD_PARTITIONS
|
||||
#define mtd_has_partitions() (1)
|
||||
#else
|
||||
#define mtd_has_partitions() (0)
|
||||
#endif
|
||||
|
||||
/****************************************************************************/
|
||||
|
||||
struct m25p {
|
||||
struct spi_device *spi;
|
||||
struct semaphore lock;
|
||||
struct mtd_info mtd;
|
||||
unsigned partitioned;
|
||||
u8 command[4];
|
||||
};
|
||||
|
||||
static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
|
||||
{
|
||||
return container_of(mtd, struct m25p, mtd);
|
||||
}
|
||||
|
||||
/****************************************************************************/
|
||||
|
||||
/*
|
||||
* Internal helper functions
|
||||
*/
|
||||
|
||||
/*
|
||||
* Read the status register, returning its value in the location
|
||||
* Return the status register value.
|
||||
* Returns negative if error occurred.
|
||||
*/
|
||||
static int read_sr(struct m25p *flash)
|
||||
{
|
||||
ssize_t retval;
|
||||
u8 code = OPCODE_RDSR;
|
||||
u8 val;
|
||||
|
||||
retval = spi_write_then_read(flash->spi, &code, 1, &val, 1);
|
||||
|
||||
if (retval < 0) {
|
||||
dev_err(&flash->spi->dev, "error %d reading SR\n",
|
||||
(int) retval);
|
||||
return retval;
|
||||
}
|
||||
|
||||
return val;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Set write enable latch with Write Enable command.
|
||||
* Returns negative if error occurred.
|
||||
*/
|
||||
static inline int write_enable(struct m25p *flash)
|
||||
{
|
||||
u8 code = OPCODE_WREN;
|
||||
|
||||
return spi_write_then_read(flash->spi, &code, 1, NULL, 0);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Service routine to read status register until ready, or timeout occurs.
|
||||
* Returns non-zero if error.
|
||||
*/
|
||||
static int wait_till_ready(struct m25p *flash)
|
||||
{
|
||||
int count;
|
||||
int sr;
|
||||
|
||||
/* one chip guarantees max 5 msec wait here after page writes,
|
||||
* but potentially three seconds (!) after page erase.
|
||||
*/
|
||||
for (count = 0; count < MAX_READY_WAIT_COUNT; count++) {
|
||||
if ((sr = read_sr(flash)) < 0)
|
||||
break;
|
||||
else if (!(sr & SR_WIP))
|
||||
return 0;
|
||||
|
||||
/* REVISIT sometimes sleeping would be best */
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Erase one sector of flash memory at offset ``offset'' which is any
|
||||
* address within the sector which should be erased.
|
||||
*
|
||||
* Returns 0 if successful, non-zero otherwise.
|
||||
*/
|
||||
static int erase_sector(struct m25p *flash, u32 offset)
|
||||
{
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "%s: %s at 0x%08x\n", flash->spi->dev.bus_id,
|
||||
__FUNCTION__, offset);
|
||||
|
||||
/* Wait until finished previous write command. */
|
||||
if (wait_till_ready(flash))
|
||||
return 1;
|
||||
|
||||
/* Send write enable, then erase commands. */
|
||||
write_enable(flash);
|
||||
|
||||
/* Set up command buffer. */
|
||||
flash->command[0] = OPCODE_SE;
|
||||
flash->command[1] = offset >> 16;
|
||||
flash->command[2] = offset >> 8;
|
||||
flash->command[3] = offset;
|
||||
|
||||
spi_write(flash->spi, flash->command, sizeof(flash->command));
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/****************************************************************************/
|
||||
|
||||
/*
|
||||
* MTD implementation
|
||||
*/
|
||||
|
||||
/*
|
||||
* Erase an address range on the flash chip. The address range may extend
|
||||
* one or more erase sectors. Return an error is there is a problem erasing.
|
||||
*/
|
||||
static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
|
||||
{
|
||||
struct m25p *flash = mtd_to_m25p(mtd);
|
||||
u32 addr,len;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
|
||||
flash->spi->dev.bus_id, __FUNCTION__, "at",
|
||||
(u32)instr->addr, instr->len);
|
||||
|
||||
/* sanity checks */
|
||||
if (instr->addr + instr->len > flash->mtd.size)
|
||||
return -EINVAL;
|
||||
if ((instr->addr % mtd->erasesize) != 0
|
||||
|| (instr->len % mtd->erasesize) != 0) {
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
addr = instr->addr;
|
||||
len = instr->len;
|
||||
|
||||
down(&flash->lock);
|
||||
|
||||
/* now erase those sectors */
|
||||
while (len) {
|
||||
if (erase_sector(flash, addr)) {
|
||||
instr->state = MTD_ERASE_FAILED;
|
||||
up(&flash->lock);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
addr += mtd->erasesize;
|
||||
len -= mtd->erasesize;
|
||||
}
|
||||
|
||||
up(&flash->lock);
|
||||
|
||||
instr->state = MTD_ERASE_DONE;
|
||||
mtd_erase_callback(instr);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Read an address range from the flash chip. The address range
|
||||
* may be any size provided it is within the physical boundaries.
|
||||
*/
|
||||
static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
|
||||
size_t *retlen, u_char *buf)
|
||||
{
|
||||
struct m25p *flash = mtd_to_m25p(mtd);
|
||||
struct spi_transfer t[2];
|
||||
struct spi_message m;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
|
||||
flash->spi->dev.bus_id, __FUNCTION__, "from",
|
||||
(u32)from, len);
|
||||
|
||||
/* sanity checks */
|
||||
if (!len)
|
||||
return 0;
|
||||
|
||||
if (from + len > flash->mtd.size)
|
||||
return -EINVAL;
|
||||
|
||||
spi_message_init(&m);
|
||||
memset(t, 0, (sizeof t));
|
||||
|
||||
t[0].tx_buf = flash->command;
|
||||
t[0].len = sizeof(flash->command);
|
||||
spi_message_add_tail(&t[0], &m);
|
||||
|
||||
t[1].rx_buf = buf;
|
||||
t[1].len = len;
|
||||
spi_message_add_tail(&t[1], &m);
|
||||
|
||||
/* Byte count starts at zero. */
|
||||
if (retlen)
|
||||
*retlen = 0;
|
||||
|
||||
down(&flash->lock);
|
||||
|
||||
/* Wait till previous write/erase is done. */
|
||||
if (wait_till_ready(flash)) {
|
||||
/* REVISIT status return?? */
|
||||
up(&flash->lock);
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* NOTE: OPCODE_FAST_READ (if available) is faster... */
|
||||
|
||||
/* Set up the write data buffer. */
|
||||
flash->command[0] = OPCODE_READ;
|
||||
flash->command[1] = from >> 16;
|
||||
flash->command[2] = from >> 8;
|
||||
flash->command[3] = from;
|
||||
|
||||
spi_sync(flash->spi, &m);
|
||||
|
||||
*retlen = m.actual_length - sizeof(flash->command);
|
||||
|
||||
up(&flash->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Write an address range to the flash chip. Data must be written in
|
||||
* FLASH_PAGESIZE chunks. The address range may be any size provided
|
||||
* it is within the physical boundaries.
|
||||
*/
|
||||
static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
|
||||
size_t *retlen, const u_char *buf)
|
||||
{
|
||||
struct m25p *flash = mtd_to_m25p(mtd);
|
||||
u32 page_offset, page_size;
|
||||
struct spi_transfer t[2];
|
||||
struct spi_message m;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
|
||||
flash->spi->dev.bus_id, __FUNCTION__, "to",
|
||||
(u32)to, len);
|
||||
|
||||
if (retlen)
|
||||
*retlen = 0;
|
||||
|
||||
/* sanity checks */
|
||||
if (!len)
|
||||
return(0);
|
||||
|
||||
if (to + len > flash->mtd.size)
|
||||
return -EINVAL;
|
||||
|
||||
spi_message_init(&m);
|
||||
memset(t, 0, (sizeof t));
|
||||
|
||||
t[0].tx_buf = flash->command;
|
||||
t[0].len = sizeof(flash->command);
|
||||
spi_message_add_tail(&t[0], &m);
|
||||
|
||||
t[1].tx_buf = buf;
|
||||
spi_message_add_tail(&t[1], &m);
|
||||
|
||||
down(&flash->lock);
|
||||
|
||||
/* Wait until finished previous write command. */
|
||||
if (wait_till_ready(flash))
|
||||
return 1;
|
||||
|
||||
write_enable(flash);
|
||||
|
||||
/* Set up the opcode in the write buffer. */
|
||||
flash->command[0] = OPCODE_PP;
|
||||
flash->command[1] = to >> 16;
|
||||
flash->command[2] = to >> 8;
|
||||
flash->command[3] = to;
|
||||
|
||||
/* what page do we start with? */
|
||||
page_offset = to % FLASH_PAGESIZE;
|
||||
|
||||
/* do all the bytes fit onto one page? */
|
||||
if (page_offset + len <= FLASH_PAGESIZE) {
|
||||
t[1].len = len;
|
||||
|
||||
spi_sync(flash->spi, &m);
|
||||
|
||||
*retlen = m.actual_length - sizeof(flash->command);
|
||||
} else {
|
||||
u32 i;
|
||||
|
||||
/* the size of data remaining on the first page */
|
||||
page_size = FLASH_PAGESIZE - page_offset;
|
||||
|
||||
t[1].len = page_size;
|
||||
spi_sync(flash->spi, &m);
|
||||
|
||||
*retlen = m.actual_length - sizeof(flash->command);
|
||||
|
||||
/* write everything in PAGESIZE chunks */
|
||||
for (i = page_size; i < len; i += page_size) {
|
||||
page_size = len - i;
|
||||
if (page_size > FLASH_PAGESIZE)
|
||||
page_size = FLASH_PAGESIZE;
|
||||
|
||||
/* write the next page to flash */
|
||||
flash->command[1] = (to + i) >> 16;
|
||||
flash->command[2] = (to + i) >> 8;
|
||||
flash->command[3] = (to + i);
|
||||
|
||||
t[1].tx_buf = buf + i;
|
||||
t[1].len = page_size;
|
||||
|
||||
wait_till_ready(flash);
|
||||
|
||||
write_enable(flash);
|
||||
|
||||
spi_sync(flash->spi, &m);
|
||||
|
||||
if (retlen)
|
||||
*retlen += m.actual_length
|
||||
- sizeof(flash->command);
|
||||
}
|
||||
}
|
||||
|
||||
up(&flash->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
/****************************************************************************/
|
||||
|
||||
/*
|
||||
* SPI device driver setup and teardown
|
||||
*/
|
||||
|
||||
struct flash_info {
|
||||
char *name;
|
||||
u8 id;
|
||||
u16 jedec_id;
|
||||
unsigned sector_size;
|
||||
unsigned n_sectors;
|
||||
};
|
||||
|
||||
static struct flash_info __devinitdata m25p_data [] = {
|
||||
/* REVISIT: fill in JEDEC ids, for parts that have them */
|
||||
{ "m25p05", 0x05, 0x0000, 32 * 1024, 2 },
|
||||
{ "m25p10", 0x10, 0x0000, 32 * 1024, 4 },
|
||||
{ "m25p20", 0x11, 0x0000, 64 * 1024, 4 },
|
||||
{ "m25p40", 0x12, 0x0000, 64 * 1024, 8 },
|
||||
{ "m25p80", 0x13, 0x0000, 64 * 1024, 16 },
|
||||
{ "m25p16", 0x14, 0x0000, 64 * 1024, 32 },
|
||||
{ "m25p32", 0x15, 0x0000, 64 * 1024, 64 },
|
||||
{ "m25p64", 0x16, 0x2017, 64 * 1024, 128 },
|
||||
};
|
||||
|
||||
/*
|
||||
* board specific setup should have ensured the SPI clock used here
|
||||
* matches what the READ command supports, at least until this driver
|
||||
* understands FAST_READ (for clocks over 25 MHz).
|
||||
*/
|
||||
static int __devinit m25p_probe(struct spi_device *spi)
|
||||
{
|
||||
struct flash_platform_data *data;
|
||||
struct m25p *flash;
|
||||
struct flash_info *info;
|
||||
unsigned i;
|
||||
|
||||
/* Platform data helps sort out which chip type we have, as
|
||||
* well as how this board partitions it.
|
||||
*/
|
||||
data = spi->dev.platform_data;
|
||||
if (!data || !data->type) {
|
||||
/* FIXME some chips can identify themselves with RES
|
||||
* or JEDEC get-id commands. Try them ...
|
||||
*/
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: no chip id\n",
|
||||
flash->spi->dev.bus_id);
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
for (i = 0, info = m25p_data; i < ARRAY_SIZE(m25p_data); i++, info++) {
|
||||
if (strcmp(data->type, info->name) == 0)
|
||||
break;
|
||||
}
|
||||
if (i == ARRAY_SIZE(m25p_data)) {
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: unrecognized id %s\n",
|
||||
flash->spi->dev.bus_id, data->type);
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
flash = kzalloc(sizeof *flash, SLAB_KERNEL);
|
||||
if (!flash)
|
||||
return -ENOMEM;
|
||||
|
||||
flash->spi = spi;
|
||||
init_MUTEX(&flash->lock);
|
||||
dev_set_drvdata(&spi->dev, flash);
|
||||
|
||||
if (data->name)
|
||||
flash->mtd.name = data->name;
|
||||
else
|
||||
flash->mtd.name = spi->dev.bus_id;
|
||||
|
||||
flash->mtd.type = MTD_NORFLASH;
|
||||
flash->mtd.flags = MTD_CAP_NORFLASH;
|
||||
flash->mtd.size = info->sector_size * info->n_sectors;
|
||||
flash->mtd.erasesize = info->sector_size;
|
||||
flash->mtd.erase = m25p80_erase;
|
||||
flash->mtd.read = m25p80_read;
|
||||
flash->mtd.write = m25p80_write;
|
||||
|
||||
dev_info(&spi->dev, "%s (%d Kbytes)\n", info->name,
|
||||
flash->mtd.size / 1024);
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2,
|
||||
"mtd .name = %s, .size = 0x%.8x (%uM) "
|
||||
".erasesize = 0x%.8x (%uK) .numeraseregions = %d\n",
|
||||
flash->mtd.name,
|
||||
flash->mtd.size, flash->mtd.size / (1024*1024),
|
||||
flash->mtd.erasesize, flash->mtd.erasesize / 1024,
|
||||
flash->mtd.numeraseregions);
|
||||
|
||||
if (flash->mtd.numeraseregions)
|
||||
for (i = 0; i < flash->mtd.numeraseregions; i++)
|
||||
DEBUG(MTD_DEBUG_LEVEL2,
|
||||
"mtd.eraseregions[%d] = { .offset = 0x%.8x, "
|
||||
".erasesize = 0x%.8x (%uK), "
|
||||
".numblocks = %d }\n",
|
||||
i, flash->mtd.eraseregions[i].offset,
|
||||
flash->mtd.eraseregions[i].erasesize,
|
||||
flash->mtd.eraseregions[i].erasesize / 1024,
|
||||
flash->mtd.eraseregions[i].numblocks);
|
||||
|
||||
|
||||
/* partitions should match sector boundaries; and it may be good to
|
||||
* use readonly partitions for writeprotected sectors (BP2..BP0).
|
||||
*/
|
||||
if (mtd_has_partitions()) {
|
||||
struct mtd_partition *parts = NULL;
|
||||
int nr_parts = 0;
|
||||
|
||||
#ifdef CONFIG_MTD_CMDLINE_PARTS
|
||||
static const char *part_probes[] = { "cmdlinepart", NULL, };
|
||||
|
||||
nr_parts = parse_mtd_partitions(&flash->mtd,
|
||||
part_probes, &parts, 0);
|
||||
#endif
|
||||
|
||||
if (nr_parts <= 0 && data && data->parts) {
|
||||
parts = data->parts;
|
||||
nr_parts = data->nr_parts;
|
||||
}
|
||||
|
||||
if (nr_parts > 0) {
|
||||
for (i = 0; i < data->nr_parts; i++) {
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
|
||||
"{.name = %s, .offset = 0x%.8x, "
|
||||
".size = 0x%.8x (%uK) }\n",
|
||||
i, data->parts[i].name,
|
||||
data->parts[i].offset,
|
||||
data->parts[i].size,
|
||||
data->parts[i].size / 1024);
|
||||
}
|
||||
flash->partitioned = 1;
|
||||
return add_mtd_partitions(&flash->mtd, parts, nr_parts);
|
||||
}
|
||||
} else if (data->nr_parts)
|
||||
dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
|
||||
data->nr_parts, data->name);
|
||||
|
||||
return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;
|
||||
}
|
||||
|
||||
|
||||
static int __devexit m25p_remove(struct spi_device *spi)
|
||||
{
|
||||
struct m25p *flash = dev_get_drvdata(&spi->dev);
|
||||
int status;
|
||||
|
||||
/* Clean up MTD stuff. */
|
||||
if (mtd_has_partitions() && flash->partitioned)
|
||||
status = del_mtd_partitions(&flash->mtd);
|
||||
else
|
||||
status = del_mtd_device(&flash->mtd);
|
||||
if (status == 0)
|
||||
kfree(flash);
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
static struct spi_driver m25p80_driver = {
|
||||
.driver = {
|
||||
.name = "m25p80",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = m25p_probe,
|
||||
.remove = __devexit_p(m25p_remove),
|
||||
};
|
||||
|
||||
|
||||
static int m25p80_init(void)
|
||||
{
|
||||
return spi_register_driver(&m25p80_driver);
|
||||
}
|
||||
|
||||
|
||||
static void m25p80_exit(void)
|
||||
{
|
||||
spi_unregister_driver(&m25p80_driver);
|
||||
}
|
||||
|
||||
|
||||
module_init(m25p80_init);
|
||||
module_exit(m25p80_exit);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Mike Lavender");
|
||||
MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");
|
||||
629
drivers/mtd/devices/mtd_dataflash.c
Normal file
629
drivers/mtd/devices/mtd_dataflash.c
Normal file
|
|
@ -0,0 +1,629 @@
|
|||
/*
|
||||
* Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
|
||||
*
|
||||
* Largely derived from at91_dataflash.c:
|
||||
* Copyright (C) 2003-2005 SAN People (Pty) Ltd
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* as published by the Free Software Foundation; either version
|
||||
* 2 of the License, or (at your option) any later version.
|
||||
*/
|
||||
#include <linux/config.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/spi/flash.h>
|
||||
|
||||
#include <linux/mtd/mtd.h>
|
||||
#include <linux/mtd/partitions.h>
|
||||
|
||||
|
||||
/*
|
||||
* DataFlash is a kind of SPI flash. Most AT45 chips have two buffers in
|
||||
* each chip, which may be used for double buffered I/O; but this driver
|
||||
* doesn't (yet) use these for any kind of i/o overlap or prefetching.
|
||||
*
|
||||
* Sometimes DataFlash is packaged in MMC-format cards, although the
|
||||
* MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash
|
||||
* protocols during enumeration.
|
||||
*/
|
||||
|
||||
#define CONFIG_DATAFLASH_WRITE_VERIFY
|
||||
|
||||
/* reads can bypass the buffers */
|
||||
#define OP_READ_CONTINUOUS 0xE8
|
||||
#define OP_READ_PAGE 0xD2
|
||||
|
||||
/* group B requests can run even while status reports "busy" */
|
||||
#define OP_READ_STATUS 0xD7 /* group B */
|
||||
|
||||
/* move data between host and buffer */
|
||||
#define OP_READ_BUFFER1 0xD4 /* group B */
|
||||
#define OP_READ_BUFFER2 0xD6 /* group B */
|
||||
#define OP_WRITE_BUFFER1 0x84 /* group B */
|
||||
#define OP_WRITE_BUFFER2 0x87 /* group B */
|
||||
|
||||
/* erasing flash */
|
||||
#define OP_ERASE_PAGE 0x81
|
||||
#define OP_ERASE_BLOCK 0x50
|
||||
|
||||
/* move data between buffer and flash */
|
||||
#define OP_TRANSFER_BUF1 0x53
|
||||
#define OP_TRANSFER_BUF2 0x55
|
||||
#define OP_MREAD_BUFFER1 0xD4
|
||||
#define OP_MREAD_BUFFER2 0xD6
|
||||
#define OP_MWERASE_BUFFER1 0x83
|
||||
#define OP_MWERASE_BUFFER2 0x86
|
||||
#define OP_MWRITE_BUFFER1 0x88 /* sector must be pre-erased */
|
||||
#define OP_MWRITE_BUFFER2 0x89 /* sector must be pre-erased */
|
||||
|
||||
/* write to buffer, then write-erase to flash */
|
||||
#define OP_PROGRAM_VIA_BUF1 0x82
|
||||
#define OP_PROGRAM_VIA_BUF2 0x85
|
||||
|
||||
/* compare buffer to flash */
|
||||
#define OP_COMPARE_BUF1 0x60
|
||||
#define OP_COMPARE_BUF2 0x61
|
||||
|
||||
/* read flash to buffer, then write-erase to flash */
|
||||
#define OP_REWRITE_VIA_BUF1 0x58
|
||||
#define OP_REWRITE_VIA_BUF2 0x59
|
||||
|
||||
/* newer chips report JEDEC manufacturer and device IDs; chip
|
||||
* serial number and OTP bits; and per-sector writeprotect.
|
||||
*/
|
||||
#define OP_READ_ID 0x9F
|
||||
#define OP_READ_SECURITY 0x77
|
||||
#define OP_WRITE_SECURITY 0x9A /* OTP bits */
|
||||
|
||||
|
||||
struct dataflash {
|
||||
u8 command[4];
|
||||
char name[24];
|
||||
|
||||
unsigned partitioned:1;
|
||||
|
||||
unsigned short page_offset; /* offset in flash address */
|
||||
unsigned int page_size; /* of bytes per page */
|
||||
|
||||
struct semaphore lock;
|
||||
struct spi_device *spi;
|
||||
|
||||
struct mtd_info mtd;
|
||||
};
|
||||
|
||||
#ifdef CONFIG_MTD_PARTITIONS
|
||||
#define mtd_has_partitions() (1)
|
||||
#else
|
||||
#define mtd_has_partitions() (0)
|
||||
#endif
|
||||
|
||||
/* ......................................................................... */
|
||||
|
||||
/*
|
||||
* Return the status of the DataFlash device.
|
||||
*/
|
||||
static inline int dataflash_status(struct spi_device *spi)
|
||||
{
|
||||
/* NOTE: at45db321c over 25 MHz wants to write
|
||||
* a dummy byte after the opcode...
|
||||
*/
|
||||
return spi_w8r8(spi, OP_READ_STATUS);
|
||||
}
|
||||
|
||||
/*
|
||||
* Poll the DataFlash device until it is READY.
|
||||
* This usually takes 5-20 msec or so; more for sector erase.
|
||||
*/
|
||||
static int dataflash_waitready(struct spi_device *spi)
|
||||
{
|
||||
int status;
|
||||
|
||||
for (;;) {
|
||||
status = dataflash_status(spi);
|
||||
if (status < 0) {
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
|
||||
spi->dev.bus_id, status);
|
||||
status = 0;
|
||||
}
|
||||
|
||||
if (status & (1 << 7)) /* RDY/nBSY */
|
||||
return status;
|
||||
|
||||
msleep(3);
|
||||
}
|
||||
}
|
||||
|
||||
/* ......................................................................... */
|
||||
|
||||
/*
|
||||
* Erase pages of flash.
|
||||
*/
|
||||
static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
|
||||
{
|
||||
struct dataflash *priv = (struct dataflash *)mtd->priv;
|
||||
struct spi_device *spi = priv->spi;
|
||||
struct spi_transfer x = { .tx_dma = 0, };
|
||||
struct spi_message msg;
|
||||
unsigned blocksize = priv->page_size << 3;
|
||||
u8 *command;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n",
|
||||
spi->dev.bus_id,
|
||||
instr->addr, instr->len);
|
||||
|
||||
/* Sanity checks */
|
||||
if ((instr->addr + instr->len) > mtd->size
|
||||
|| (instr->len % priv->page_size) != 0
|
||||
|| (instr->addr % priv->page_size) != 0)
|
||||
return -EINVAL;
|
||||
|
||||
spi_message_init(&msg);
|
||||
|
||||
x.tx_buf = command = priv->command;
|
||||
x.len = 4;
|
||||
spi_message_add_tail(&x, &msg);
|
||||
|
||||
down(&priv->lock);
|
||||
while (instr->len > 0) {
|
||||
unsigned int pageaddr;
|
||||
int status;
|
||||
int do_block;
|
||||
|
||||
/* Calculate flash page address; use block erase (for speed) if
|
||||
* we're at a block boundary and need to erase the whole block.
|
||||
*/
|
||||
pageaddr = instr->addr / priv->page_size;
|
||||
do_block = (pageaddr & 0x7) == 0 && instr->len <= blocksize;
|
||||
pageaddr = pageaddr << priv->page_offset;
|
||||
|
||||
command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
|
||||
command[1] = (u8)(pageaddr >> 16);
|
||||
command[2] = (u8)(pageaddr >> 8);
|
||||
command[3] = 0;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
|
||||
do_block ? "block" : "page",
|
||||
command[0], command[1], command[2], command[3],
|
||||
pageaddr);
|
||||
|
||||
status = spi_sync(spi, &msg);
|
||||
(void) dataflash_waitready(spi);
|
||||
|
||||
if (status < 0) {
|
||||
printk(KERN_ERR "%s: erase %x, err %d\n",
|
||||
spi->dev.bus_id, pageaddr, status);
|
||||
/* REVISIT: can retry instr->retries times; or
|
||||
* giveup and instr->fail_addr = instr->addr;
|
||||
*/
|
||||
continue;
|
||||
}
|
||||
|
||||
if (do_block) {
|
||||
instr->addr += blocksize;
|
||||
instr->len -= blocksize;
|
||||
} else {
|
||||
instr->addr += priv->page_size;
|
||||
instr->len -= priv->page_size;
|
||||
}
|
||||
}
|
||||
up(&priv->lock);
|
||||
|
||||
/* Inform MTD subsystem that erase is complete */
|
||||
instr->state = MTD_ERASE_DONE;
|
||||
mtd_erase_callback(instr);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Read from the DataFlash device.
|
||||
* from : Start offset in flash device
|
||||
* len : Amount to read
|
||||
* retlen : About of data actually read
|
||||
* buf : Buffer containing the data
|
||||
*/
|
||||
static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
|
||||
size_t *retlen, u_char *buf)
|
||||
{
|
||||
struct dataflash *priv = (struct dataflash *)mtd->priv;
|
||||
struct spi_transfer x[2] = { { .tx_dma = 0, }, };
|
||||
struct spi_message msg;
|
||||
unsigned int addr;
|
||||
u8 *command;
|
||||
int status;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
|
||||
priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len));
|
||||
|
||||
*retlen = 0;
|
||||
|
||||
/* Sanity checks */
|
||||
if (!len)
|
||||
return 0;
|
||||
if (from + len > mtd->size)
|
||||
return -EINVAL;
|
||||
|
||||
/* Calculate flash page/byte address */
|
||||
addr = (((unsigned)from / priv->page_size) << priv->page_offset)
|
||||
+ ((unsigned)from % priv->page_size);
|
||||
|
||||
command = priv->command;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
|
||||
command[0], command[1], command[2], command[3]);
|
||||
|
||||
spi_message_init(&msg);
|
||||
|
||||
x[0].tx_buf = command;
|
||||
x[0].len = 8;
|
||||
spi_message_add_tail(&x[0], &msg);
|
||||
|
||||
x[1].rx_buf = buf;
|
||||
x[1].len = len;
|
||||
spi_message_add_tail(&x[1], &msg);
|
||||
|
||||
down(&priv->lock);
|
||||
|
||||
/* Continuous read, max clock = f(car) which may be less than
|
||||
* the peak rate available. Some chips support commands with
|
||||
* fewer "don't care" bytes. Both buffers stay unchanged.
|
||||
*/
|
||||
command[0] = OP_READ_CONTINUOUS;
|
||||
command[1] = (u8)(addr >> 16);
|
||||
command[2] = (u8)(addr >> 8);
|
||||
command[3] = (u8)(addr >> 0);
|
||||
/* plus 4 "don't care" bytes */
|
||||
|
||||
status = spi_sync(priv->spi, &msg);
|
||||
up(&priv->lock);
|
||||
|
||||
if (status >= 0) {
|
||||
*retlen = msg.actual_length - 8;
|
||||
status = 0;
|
||||
} else
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
|
||||
priv->spi->dev.bus_id,
|
||||
(unsigned)from, (unsigned)(from + len),
|
||||
status);
|
||||
return status;
|
||||
}
|
||||
|
||||
/*
|
||||
* Write to the DataFlash device.
|
||||
* to : Start offset in flash device
|
||||
* len : Amount to write
|
||||
* retlen : Amount of data actually written
|
||||
* buf : Buffer containing the data
|
||||
*/
|
||||
static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
|
||||
size_t * retlen, const u_char * buf)
|
||||
{
|
||||
struct dataflash *priv = (struct dataflash *)mtd->priv;
|
||||
struct spi_device *spi = priv->spi;
|
||||
struct spi_transfer x[2] = { { .tx_dma = 0, }, };
|
||||
struct spi_message msg;
|
||||
unsigned int pageaddr, addr, offset, writelen;
|
||||
size_t remaining = len;
|
||||
u_char *writebuf = (u_char *) buf;
|
||||
int status = -EINVAL;
|
||||
u8 *command;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
|
||||
spi->dev.bus_id, (unsigned)to, (unsigned)(to + len));
|
||||
|
||||
*retlen = 0;
|
||||
|
||||
/* Sanity checks */
|
||||
if (!len)
|
||||
return 0;
|
||||
if ((to + len) > mtd->size)
|
||||
return -EINVAL;
|
||||
|
||||
spi_message_init(&msg);
|
||||
|
||||
x[0].tx_buf = command = priv->command;
|
||||
x[0].len = 4;
|
||||
spi_message_add_tail(&x[0], &msg);
|
||||
|
||||
pageaddr = ((unsigned)to / priv->page_size);
|
||||
offset = ((unsigned)to % priv->page_size);
|
||||
if (offset + len > priv->page_size)
|
||||
writelen = priv->page_size - offset;
|
||||
else
|
||||
writelen = len;
|
||||
|
||||
down(&priv->lock);
|
||||
while (remaining > 0) {
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
|
||||
pageaddr, offset, writelen);
|
||||
|
||||
/* REVISIT:
|
||||
* (a) each page in a sector must be rewritten at least
|
||||
* once every 10K sibling erase/program operations.
|
||||
* (b) for pages that are already erased, we could
|
||||
* use WRITE+MWRITE not PROGRAM for ~30% speedup.
|
||||
* (c) WRITE to buffer could be done while waiting for
|
||||
* a previous MWRITE/MWERASE to complete ...
|
||||
* (d) error handling here seems to be mostly missing.
|
||||
*
|
||||
* Two persistent bits per page, plus a per-sector counter,
|
||||
* could support (a) and (b) ... we might consider using
|
||||
* the second half of sector zero, which is just one block,
|
||||
* to track that state. (On AT91, that sector should also
|
||||
* support boot-from-DataFlash.)
|
||||
*/
|
||||
|
||||
addr = pageaddr << priv->page_offset;
|
||||
|
||||
/* (1) Maybe transfer partial page to Buffer1 */
|
||||
if (writelen != priv->page_size) {
|
||||
command[0] = OP_TRANSFER_BUF1;
|
||||
command[1] = (addr & 0x00FF0000) >> 16;
|
||||
command[2] = (addr & 0x0000FF00) >> 8;
|
||||
command[3] = 0;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
|
||||
command[0], command[1], command[2], command[3]);
|
||||
|
||||
status = spi_sync(spi, &msg);
|
||||
if (status < 0)
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
|
||||
spi->dev.bus_id, addr, status);
|
||||
|
||||
(void) dataflash_waitready(priv->spi);
|
||||
}
|
||||
|
||||
/* (2) Program full page via Buffer1 */
|
||||
addr += offset;
|
||||
command[0] = OP_PROGRAM_VIA_BUF1;
|
||||
command[1] = (addr & 0x00FF0000) >> 16;
|
||||
command[2] = (addr & 0x0000FF00) >> 8;
|
||||
command[3] = (addr & 0x000000FF);
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
|
||||
command[0], command[1], command[2], command[3]);
|
||||
|
||||
x[1].tx_buf = writebuf;
|
||||
x[1].len = writelen;
|
||||
spi_message_add_tail(x + 1, &msg);
|
||||
status = spi_sync(spi, &msg);
|
||||
spi_transfer_del(x + 1);
|
||||
if (status < 0)
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
|
||||
spi->dev.bus_id, addr, writelen, status);
|
||||
|
||||
(void) dataflash_waitready(priv->spi);
|
||||
|
||||
|
||||
#ifdef CONFIG_DATAFLASH_WRITE_VERIFY
|
||||
|
||||
/* (3) Compare to Buffer1 */
|
||||
addr = pageaddr << priv->page_offset;
|
||||
command[0] = OP_COMPARE_BUF1;
|
||||
command[1] = (addr & 0x00FF0000) >> 16;
|
||||
command[2] = (addr & 0x0000FF00) >> 8;
|
||||
command[3] = 0;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
|
||||
command[0], command[1], command[2], command[3]);
|
||||
|
||||
status = spi_sync(spi, &msg);
|
||||
if (status < 0)
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
|
||||
spi->dev.bus_id, addr, status);
|
||||
|
||||
status = dataflash_waitready(priv->spi);
|
||||
|
||||
/* Check result of the compare operation */
|
||||
if ((status & (1 << 6)) == 1) {
|
||||
printk(KERN_ERR "%s: compare page %u, err %d\n",
|
||||
spi->dev.bus_id, pageaddr, status);
|
||||
remaining = 0;
|
||||
status = -EIO;
|
||||
break;
|
||||
} else
|
||||
status = 0;
|
||||
|
||||
#endif /* CONFIG_DATAFLASH_WRITE_VERIFY */
|
||||
|
||||
remaining = remaining - writelen;
|
||||
pageaddr++;
|
||||
offset = 0;
|
||||
writebuf += writelen;
|
||||
*retlen += writelen;
|
||||
|
||||
if (remaining > priv->page_size)
|
||||
writelen = priv->page_size;
|
||||
else
|
||||
writelen = remaining;
|
||||
}
|
||||
up(&priv->lock);
|
||||
|
||||
return status;
|
||||
}
|
||||
|
||||
/* ......................................................................... */
|
||||
|
||||
/*
|
||||
* Register DataFlash device with MTD subsystem.
|
||||
*/
|
||||
static int __devinit
|
||||
add_dataflash(struct spi_device *spi, char *name,
|
||||
int nr_pages, int pagesize, int pageoffset)
|
||||
{
|
||||
struct dataflash *priv;
|
||||
struct mtd_info *device;
|
||||
struct flash_platform_data *pdata = spi->dev.platform_data;
|
||||
|
||||
priv = (struct dataflash *) kzalloc(sizeof *priv, GFP_KERNEL);
|
||||
if (!priv)
|
||||
return -ENOMEM;
|
||||
|
||||
init_MUTEX(&priv->lock);
|
||||
priv->spi = spi;
|
||||
priv->page_size = pagesize;
|
||||
priv->page_offset = pageoffset;
|
||||
|
||||
/* name must be usable with cmdlinepart */
|
||||
sprintf(priv->name, "spi%d.%d-%s",
|
||||
spi->master->bus_num, spi->chip_select,
|
||||
name);
|
||||
|
||||
device = &priv->mtd;
|
||||
device->name = (pdata && pdata->name) ? pdata->name : priv->name;
|
||||
device->size = nr_pages * pagesize;
|
||||
device->erasesize = pagesize;
|
||||
device->owner = THIS_MODULE;
|
||||
device->type = MTD_DATAFLASH;
|
||||
device->flags = MTD_CAP_NORFLASH;
|
||||
device->erase = dataflash_erase;
|
||||
device->read = dataflash_read;
|
||||
device->write = dataflash_write;
|
||||
device->priv = priv;
|
||||
|
||||
dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024);
|
||||
dev_set_drvdata(&spi->dev, priv);
|
||||
|
||||
if (mtd_has_partitions()) {
|
||||
struct mtd_partition *parts;
|
||||
int nr_parts = 0;
|
||||
|
||||
#ifdef CONFIG_MTD_CMDLINE_PARTS
|
||||
static const char *part_probes[] = { "cmdlinepart", NULL, };
|
||||
|
||||
nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0);
|
||||
#endif
|
||||
|
||||
if (nr_parts <= 0 && pdata && pdata->parts) {
|
||||
parts = pdata->parts;
|
||||
nr_parts = pdata->nr_parts;
|
||||
}
|
||||
|
||||
if (nr_parts > 0) {
|
||||
priv->partitioned = 1;
|
||||
return add_mtd_partitions(device, parts, nr_parts);
|
||||
}
|
||||
} else if (pdata && pdata->nr_parts)
|
||||
dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
|
||||
pdata->nr_parts, device->name);
|
||||
|
||||
return add_mtd_device(device) == 1 ? -ENODEV : 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Detect and initialize DataFlash device:
|
||||
*
|
||||
* Device Density ID code #Pages PageSize Offset
|
||||
* AT45DB011B 1Mbit (128K) xx0011xx (0x0c) 512 264 9
|
||||
* AT45DB021B 2Mbit (256K) xx0101xx (0x14) 1025 264 9
|
||||
* AT45DB041B 4Mbit (512K) xx0111xx (0x1c) 2048 264 9
|
||||
* AT45DB081B 8Mbit (1M) xx1001xx (0x24) 4096 264 9
|
||||
* AT45DB0161B 16Mbit (2M) xx1011xx (0x2c) 4096 528 10
|
||||
* AT45DB0321B 32Mbit (4M) xx1101xx (0x34) 8192 528 10
|
||||
* AT45DB0642 64Mbit (8M) xx111xxx (0x3c) 8192 1056 11
|
||||
* AT45DB1282 128Mbit (16M) xx0100xx (0x10) 16384 1056 11
|
||||
*/
|
||||
static int __devinit dataflash_probe(struct spi_device *spi)
|
||||
{
|
||||
int status;
|
||||
|
||||
status = dataflash_status(spi);
|
||||
if (status <= 0 || status == 0xff) {
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
|
||||
spi->dev.bus_id, status);
|
||||
if (status == 0xff)
|
||||
status = -ENODEV;
|
||||
return status;
|
||||
}
|
||||
|
||||
/* if there's a device there, assume it's dataflash.
|
||||
* board setup should have set spi->max_speed_max to
|
||||
* match f(car) for continuous reads, mode 0 or 3.
|
||||
*/
|
||||
switch (status & 0x3c) {
|
||||
case 0x0c: /* 0 0 1 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
|
||||
break;
|
||||
case 0x14: /* 0 1 0 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9);
|
||||
break;
|
||||
case 0x1c: /* 0 1 1 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
|
||||
break;
|
||||
case 0x24: /* 1 0 0 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
|
||||
break;
|
||||
case 0x2c: /* 1 0 1 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
|
||||
break;
|
||||
case 0x34: /* 1 1 0 1 x x */
|
||||
status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
|
||||
break;
|
||||
case 0x38: /* 1 1 1 x x x */
|
||||
case 0x3c:
|
||||
status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
|
||||
break;
|
||||
/* obsolete AT45DB1282 not (yet?) supported */
|
||||
default:
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
|
||||
spi->dev.bus_id, status & 0x3c);
|
||||
status = -ENODEV;
|
||||
}
|
||||
|
||||
if (status < 0)
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
|
||||
spi->dev.bus_id, status);
|
||||
|
||||
return status;
|
||||
}
|
||||
|
||||
static int __devexit dataflash_remove(struct spi_device *spi)
|
||||
{
|
||||
struct dataflash *flash = dev_get_drvdata(&spi->dev);
|
||||
int status;
|
||||
|
||||
DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id);
|
||||
|
||||
if (mtd_has_partitions() && flash->partitioned)
|
||||
status = del_mtd_partitions(&flash->mtd);
|
||||
else
|
||||
status = del_mtd_device(&flash->mtd);
|
||||
if (status == 0)
|
||||
kfree(flash);
|
||||
return status;
|
||||
}
|
||||
|
||||
static struct spi_driver dataflash_driver = {
|
||||
.driver = {
|
||||
.name = "mtd_dataflash",
|
||||
.bus = &spi_bus_type,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
|
||||
.probe = dataflash_probe,
|
||||
.remove = __devexit_p(dataflash_remove),
|
||||
|
||||
/* FIXME: investigate suspend and resume... */
|
||||
};
|
||||
|
||||
static int __init dataflash_init(void)
|
||||
{
|
||||
return spi_register_driver(&dataflash_driver);
|
||||
}
|
||||
module_init(dataflash_init);
|
||||
|
||||
static void __exit dataflash_exit(void)
|
||||
{
|
||||
spi_unregister_driver(&dataflash_driver);
|
||||
}
|
||||
module_exit(dataflash_exit);
|
||||
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Andrew Victor, David Brownell");
|
||||
MODULE_DESCRIPTION("MTD DataFlash driver");
|
||||
109
drivers/spi/Kconfig
Normal file
109
drivers/spi/Kconfig
Normal file
|
|
@ -0,0 +1,109 @@
|
|||
#
|
||||
# SPI driver configuration
|
||||
#
|
||||
# NOTE: the reason this doesn't show SPI slave support is mostly that
|
||||
# nobody's needed a slave side API yet. The master-role API is not
|
||||
# fully appropriate there, so it'd need some thought to do well.
|
||||
#
|
||||
menu "SPI support"
|
||||
|
||||
config SPI
|
||||
bool "SPI support"
|
||||
help
|
||||
The "Serial Peripheral Interface" is a low level synchronous
|
||||
protocol. Chips that support SPI can have data transfer rates
|
||||
up to several tens of Mbit/sec. Chips are addressed with a
|
||||
controller and a chipselect. Most SPI slaves don't support
|
||||
dynamic device discovery; some are even write-only or read-only.
|
||||
|
||||
SPI is widely used by microcontollers to talk with sensors,
|
||||
eeprom and flash memory, codecs and various other controller
|
||||
chips, analog to digital (and d-to-a) converters, and more.
|
||||
MMC and SD cards can be accessed using SPI protocol; and for
|
||||
DataFlash cards used in MMC sockets, SPI must always be used.
|
||||
|
||||
SPI is one of a family of similar protocols using a four wire
|
||||
interface (select, clock, data in, data out) including Microwire
|
||||
(half duplex), SSP, SSI, and PSP. This driver framework should
|
||||
work with most such devices and controllers.
|
||||
|
||||
config SPI_DEBUG
|
||||
boolean "Debug support for SPI drivers"
|
||||
depends on SPI && DEBUG_KERNEL
|
||||
help
|
||||
Say "yes" to enable debug messaging (like dev_dbg and pr_debug),
|
||||
sysfs, and debugfs support in SPI controller and protocol drivers.
|
||||
|
||||
#
|
||||
# MASTER side ... talking to discrete SPI slave chips including microcontrollers
|
||||
#
|
||||
|
||||
config SPI_MASTER
|
||||
# boolean "SPI Master Support"
|
||||
boolean
|
||||
default SPI
|
||||
help
|
||||
If your system has an master-capable SPI controller (which
|
||||
provides the clock and chipselect), you can enable that
|
||||
controller and the protocol drivers for the SPI slave chips
|
||||
that are connected.
|
||||
|
||||
comment "SPI Master Controller Drivers"
|
||||
depends on SPI_MASTER
|
||||
|
||||
config SPI_BITBANG
|
||||
tristate "Bitbanging SPI master"
|
||||
depends on SPI_MASTER && EXPERIMENTAL
|
||||
help
|
||||
With a few GPIO pins, your system can bitbang the SPI protocol.
|
||||
Select this to get SPI support through I/O pins (GPIO, parallel
|
||||
port, etc). Or, some systems' SPI master controller drivers use
|
||||
this code to manage the per-word or per-transfer accesses to the
|
||||
hardware shift registers.
|
||||
|
||||
This is library code, and is automatically selected by drivers that
|
||||
need it. You only need to select this explicitly to support driver
|
||||
modules that aren't part of this kernel tree.
|
||||
|
||||
config SPI_BUTTERFLY
|
||||
tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
|
||||
depends on SPI_MASTER && PARPORT && EXPERIMENTAL
|
||||
select SPI_BITBANG
|
||||
help
|
||||
This uses a custom parallel port cable to connect to an AVR
|
||||
Butterfly <http://www.atmel.com/products/avr/butterfly>, an
|
||||
inexpensive battery powered microcontroller evaluation board.
|
||||
This same cable can be used to flash new firmware.
|
||||
|
||||
config SPI_BUTTERFLY
|
||||
tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
|
||||
depends on SPI_MASTER && PARPORT && EXPERIMENTAL
|
||||
select SPI_BITBANG
|
||||
help
|
||||
This uses a custom parallel port cable to connect to an AVR
|
||||
Butterfly <http://www.atmel.com/products/avr/butterfly>, an
|
||||
inexpensive battery powered microcontroller evaluation board.
|
||||
This same cable can be used to flash new firmware.
|
||||
|
||||
#
|
||||
# Add new SPI master controllers in alphabetical order above this line
|
||||
#
|
||||
|
||||
|
||||
#
|
||||
# There are lots of SPI device types, with sensors and memory
|
||||
# being probably the most widely used ones.
|
||||
#
|
||||
comment "SPI Protocol Masters"
|
||||
depends on SPI_MASTER
|
||||
|
||||
|
||||
#
|
||||
# Add new SPI protocol masters in alphabetical order above this line
|
||||
#
|
||||
|
||||
|
||||
# (slave support would go here)
|
||||
|
||||
endmenu # "SPI support"
|
||||
|
||||
25
drivers/spi/Makefile
Normal file
25
drivers/spi/Makefile
Normal file
|
|
@ -0,0 +1,25 @@
|
|||
#
|
||||
# Makefile for kernel SPI drivers.
|
||||
#
|
||||
|
||||
ifeq ($(CONFIG_SPI_DEBUG),y)
|
||||
EXTRA_CFLAGS += -DDEBUG
|
||||
endif
|
||||
|
||||
# small core, mostly translating board-specific
|
||||
# config declarations into driver model code
|
||||
obj-$(CONFIG_SPI_MASTER) += spi.o
|
||||
|
||||
# SPI master controller drivers (bus)
|
||||
obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o
|
||||
obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o
|
||||
# ... add above this line ...
|
||||
|
||||
# SPI protocol drivers (device/link on bus)
|
||||
# ... add above this line ...
|
||||
|
||||
# SPI slave controller drivers (upstream link)
|
||||
# ... add above this line ...
|
||||
|
||||
# SPI slave drivers (protocol for that link)
|
||||
# ... add above this line ...
|
||||
642
drivers/spi/spi.c
Normal file
642
drivers/spi/spi.c
Normal file
|
|
@ -0,0 +1,642 @@
|
|||
/*
|
||||
* spi.c - SPI init/core code
|
||||
*
|
||||
* Copyright (C) 2005 David Brownell
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
#include <linux/autoconf.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/cache.h>
|
||||
#include <linux/spi/spi.h>
|
||||
|
||||
|
||||
/* SPI bustype and spi_master class are registered after board init code
|
||||
* provides the SPI device tables, ensuring that both are present by the
|
||||
* time controller driver registration causes spi_devices to "enumerate".
|
||||
*/
|
||||
static void spidev_release(struct device *dev)
|
||||
{
|
||||
const struct spi_device *spi = to_spi_device(dev);
|
||||
|
||||
/* spi masters may cleanup for released devices */
|
||||
if (spi->master->cleanup)
|
||||
spi->master->cleanup(spi);
|
||||
|
||||
spi_master_put(spi->master);
|
||||
kfree(dev);
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
modalias_show(struct device *dev, struct device_attribute *a, char *buf)
|
||||
{
|
||||
const struct spi_device *spi = to_spi_device(dev);
|
||||
|
||||
return snprintf(buf, BUS_ID_SIZE + 1, "%s\n", spi->modalias);
|
||||
}
|
||||
|
||||
static struct device_attribute spi_dev_attrs[] = {
|
||||
__ATTR_RO(modalias),
|
||||
__ATTR_NULL,
|
||||
};
|
||||
|
||||
/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
|
||||
* and the sysfs version makes coldplug work too.
|
||||
*/
|
||||
|
||||
static int spi_match_device(struct device *dev, struct device_driver *drv)
|
||||
{
|
||||
const struct spi_device *spi = to_spi_device(dev);
|
||||
|
||||
return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0;
|
||||
}
|
||||
|
||||
static int spi_uevent(struct device *dev, char **envp, int num_envp,
|
||||
char *buffer, int buffer_size)
|
||||
{
|
||||
const struct spi_device *spi = to_spi_device(dev);
|
||||
|
||||
envp[0] = buffer;
|
||||
snprintf(buffer, buffer_size, "MODALIAS=%s", spi->modalias);
|
||||
envp[1] = NULL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_PM
|
||||
|
||||
/*
|
||||
* NOTE: the suspend() method for an spi_master controller driver
|
||||
* should verify that all its child devices are marked as suspended;
|
||||
* suspend requests delivered through sysfs power/state files don't
|
||||
* enforce such constraints.
|
||||
*/
|
||||
static int spi_suspend(struct device *dev, pm_message_t message)
|
||||
{
|
||||
int value;
|
||||
struct spi_driver *drv = to_spi_driver(dev->driver);
|
||||
|
||||
if (!drv->suspend)
|
||||
return 0;
|
||||
|
||||
/* suspend will stop irqs and dma; no more i/o */
|
||||
value = drv->suspend(to_spi_device(dev), message);
|
||||
if (value == 0)
|
||||
dev->power.power_state = message;
|
||||
return value;
|
||||
}
|
||||
|
||||
static int spi_resume(struct device *dev)
|
||||
{
|
||||
int value;
|
||||
struct spi_driver *drv = to_spi_driver(dev->driver);
|
||||
|
||||
if (!drv->resume)
|
||||
return 0;
|
||||
|
||||
/* resume may restart the i/o queue */
|
||||
value = drv->resume(to_spi_device(dev));
|
||||
if (value == 0)
|
||||
dev->power.power_state = PMSG_ON;
|
||||
return value;
|
||||
}
|
||||
|
||||
#else
|
||||
#define spi_suspend NULL
|
||||
#define spi_resume NULL
|
||||
#endif
|
||||
|
||||
struct bus_type spi_bus_type = {
|
||||
.name = "spi",
|
||||
.dev_attrs = spi_dev_attrs,
|
||||
.match = spi_match_device,
|
||||
.uevent = spi_uevent,
|
||||
.suspend = spi_suspend,
|
||||
.resume = spi_resume,
|
||||
};
|
||||
EXPORT_SYMBOL_GPL(spi_bus_type);
|
||||
|
||||
|
||||
static int spi_drv_probe(struct device *dev)
|
||||
{
|
||||
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
||||
|
||||
return sdrv->probe(to_spi_device(dev));
|
||||
}
|
||||
|
||||
static int spi_drv_remove(struct device *dev)
|
||||
{
|
||||
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
||||
|
||||
return sdrv->remove(to_spi_device(dev));
|
||||
}
|
||||
|
||||
static void spi_drv_shutdown(struct device *dev)
|
||||
{
|
||||
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
||||
|
||||
sdrv->shutdown(to_spi_device(dev));
|
||||
}
|
||||
|
||||
int spi_register_driver(struct spi_driver *sdrv)
|
||||
{
|
||||
sdrv->driver.bus = &spi_bus_type;
|
||||
if (sdrv->probe)
|
||||
sdrv->driver.probe = spi_drv_probe;
|
||||
if (sdrv->remove)
|
||||
sdrv->driver.remove = spi_drv_remove;
|
||||
if (sdrv->shutdown)
|
||||
sdrv->driver.shutdown = spi_drv_shutdown;
|
||||
return driver_register(&sdrv->driver);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_register_driver);
|
||||
|
||||
/*-------------------------------------------------------------------------*/
|
||||
|
||||
/* SPI devices should normally not be created by SPI device drivers; that
|
||||
* would make them board-specific. Similarly with SPI master drivers.
|
||||
* Device registration normally goes into like arch/.../mach.../board-YYY.c
|
||||
* with other readonly (flashable) information about mainboard devices.
|
||||
*/
|
||||
|
||||
struct boardinfo {
|
||||
struct list_head list;
|
||||
unsigned n_board_info;
|
||||
struct spi_board_info board_info[0];
|
||||
};
|
||||
|
||||
static LIST_HEAD(board_list);
|
||||
static DECLARE_MUTEX(board_lock);
|
||||
|
||||
|
||||
/* On typical mainboards, this is purely internal; and it's not needed
|
||||
* after board init creates the hard-wired devices. Some development
|
||||
* platforms may not be able to use spi_register_board_info though, and
|
||||
* this is exported so that for example a USB or parport based adapter
|
||||
* driver could add devices (which it would learn about out-of-band).
|
||||
*/
|
||||
struct spi_device *__init_or_module
|
||||
spi_new_device(struct spi_master *master, struct spi_board_info *chip)
|
||||
{
|
||||
struct spi_device *proxy;
|
||||
struct device *dev = master->cdev.dev;
|
||||
int status;
|
||||
|
||||
/* NOTE: caller did any chip->bus_num checks necessary */
|
||||
|
||||
if (!spi_master_get(master))
|
||||
return NULL;
|
||||
|
||||
proxy = kzalloc(sizeof *proxy, GFP_KERNEL);
|
||||
if (!proxy) {
|
||||
dev_err(dev, "can't alloc dev for cs%d\n",
|
||||
chip->chip_select);
|
||||
goto fail;
|
||||
}
|
||||
proxy->master = master;
|
||||
proxy->chip_select = chip->chip_select;
|
||||
proxy->max_speed_hz = chip->max_speed_hz;
|
||||
proxy->irq = chip->irq;
|
||||
proxy->modalias = chip->modalias;
|
||||
|
||||
snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id,
|
||||
"%s.%u", master->cdev.class_id,
|
||||
chip->chip_select);
|
||||
proxy->dev.parent = dev;
|
||||
proxy->dev.bus = &spi_bus_type;
|
||||
proxy->dev.platform_data = (void *) chip->platform_data;
|
||||
proxy->controller_data = chip->controller_data;
|
||||
proxy->controller_state = NULL;
|
||||
proxy->dev.release = spidev_release;
|
||||
|
||||
/* drivers may modify this default i/o setup */
|
||||
status = master->setup(proxy);
|
||||
if (status < 0) {
|
||||
dev_dbg(dev, "can't %s %s, status %d\n",
|
||||
"setup", proxy->dev.bus_id, status);
|
||||
goto fail;
|
||||
}
|
||||
|
||||
/* driver core catches callers that misbehave by defining
|
||||
* devices that already exist.
|
||||
*/
|
||||
status = device_register(&proxy->dev);
|
||||
if (status < 0) {
|
||||
dev_dbg(dev, "can't %s %s, status %d\n",
|
||||
"add", proxy->dev.bus_id, status);
|
||||
goto fail;
|
||||
}
|
||||
dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id);
|
||||
return proxy;
|
||||
|
||||
fail:
|
||||
spi_master_put(master);
|
||||
kfree(proxy);
|
||||
return NULL;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_new_device);
|
||||
|
||||
/*
|
||||
* Board-specific early init code calls this (probably during arch_initcall)
|
||||
* with segments of the SPI device table. Any device nodes are created later,
|
||||
* after the relevant parent SPI controller (bus_num) is defined. We keep
|
||||
* this table of devices forever, so that reloading a controller driver will
|
||||
* not make Linux forget about these hard-wired devices.
|
||||
*
|
||||
* Other code can also call this, e.g. a particular add-on board might provide
|
||||
* SPI devices through its expansion connector, so code initializing that board
|
||||
* would naturally declare its SPI devices.
|
||||
*
|
||||
* The board info passed can safely be __initdata ... but be careful of
|
||||
* any embedded pointers (platform_data, etc), they're copied as-is.
|
||||
*/
|
||||
int __init
|
||||
spi_register_board_info(struct spi_board_info const *info, unsigned n)
|
||||
{
|
||||
struct boardinfo *bi;
|
||||
|
||||
bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
|
||||
if (!bi)
|
||||
return -ENOMEM;
|
||||
bi->n_board_info = n;
|
||||
memcpy(bi->board_info, info, n * sizeof *info);
|
||||
|
||||
down(&board_lock);
|
||||
list_add_tail(&bi->list, &board_list);
|
||||
up(&board_lock);
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_register_board_info);
|
||||
|
||||
/* FIXME someone should add support for a __setup("spi", ...) that
|
||||
* creates board info from kernel command lines
|
||||
*/
|
||||
|
||||
static void __init_or_module
|
||||
scan_boardinfo(struct spi_master *master)
|
||||
{
|
||||
struct boardinfo *bi;
|
||||
struct device *dev = master->cdev.dev;
|
||||
|
||||
down(&board_lock);
|
||||
list_for_each_entry(bi, &board_list, list) {
|
||||
struct spi_board_info *chip = bi->board_info;
|
||||
unsigned n;
|
||||
|
||||
for (n = bi->n_board_info; n > 0; n--, chip++) {
|
||||
if (chip->bus_num != master->bus_num)
|
||||
continue;
|
||||
/* some controllers only have one chip, so they
|
||||
* might not use chipselects. otherwise, the
|
||||
* chipselects are numbered 0..max.
|
||||
*/
|
||||
if (chip->chip_select >= master->num_chipselect
|
||||
&& master->num_chipselect) {
|
||||
dev_dbg(dev, "cs%d > max %d\n",
|
||||
chip->chip_select,
|
||||
master->num_chipselect);
|
||||
continue;
|
||||
}
|
||||
(void) spi_new_device(master, chip);
|
||||
}
|
||||
}
|
||||
up(&board_lock);
|
||||
}
|
||||
|
||||
/*-------------------------------------------------------------------------*/
|
||||
|
||||
static void spi_master_release(struct class_device *cdev)
|
||||
{
|
||||
struct spi_master *master;
|
||||
|
||||
master = container_of(cdev, struct spi_master, cdev);
|
||||
kfree(master);
|
||||
}
|
||||
|
||||
static struct class spi_master_class = {
|
||||
.name = "spi_master",
|
||||
.owner = THIS_MODULE,
|
||||
.release = spi_master_release,
|
||||
};
|
||||
|
||||
|
||||
/**
|
||||
* spi_alloc_master - allocate SPI master controller
|
||||
* @dev: the controller, possibly using the platform_bus
|
||||
* @size: how much driver-private data to preallocate; the pointer to this
|
||||
* memory is in the class_data field of the returned class_device,
|
||||
* accessible with spi_master_get_devdata().
|
||||
*
|
||||
* This call is used only by SPI master controller drivers, which are the
|
||||
* only ones directly touching chip registers. It's how they allocate
|
||||
* an spi_master structure, prior to calling spi_add_master().
|
||||
*
|
||||
* This must be called from context that can sleep. It returns the SPI
|
||||
* master structure on success, else NULL.
|
||||
*
|
||||
* The caller is responsible for assigning the bus number and initializing
|
||||
* the master's methods before calling spi_add_master(); and (after errors
|
||||
* adding the device) calling spi_master_put() to prevent a memory leak.
|
||||
*/
|
||||
struct spi_master * __init_or_module
|
||||
spi_alloc_master(struct device *dev, unsigned size)
|
||||
{
|
||||
struct spi_master *master;
|
||||
|
||||
if (!dev)
|
||||
return NULL;
|
||||
|
||||
master = kzalloc(size + sizeof *master, SLAB_KERNEL);
|
||||
if (!master)
|
||||
return NULL;
|
||||
|
||||
class_device_initialize(&master->cdev);
|
||||
master->cdev.class = &spi_master_class;
|
||||
master->cdev.dev = get_device(dev);
|
||||
spi_master_set_devdata(master, &master[1]);
|
||||
|
||||
return master;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_alloc_master);
|
||||
|
||||
/**
|
||||
* spi_register_master - register SPI master controller
|
||||
* @master: initialized master, originally from spi_alloc_master()
|
||||
*
|
||||
* SPI master controllers connect to their drivers using some non-SPI bus,
|
||||
* such as the platform bus. The final stage of probe() in that code
|
||||
* includes calling spi_register_master() to hook up to this SPI bus glue.
|
||||
*
|
||||
* SPI controllers use board specific (often SOC specific) bus numbers,
|
||||
* and board-specific addressing for SPI devices combines those numbers
|
||||
* with chip select numbers. Since SPI does not directly support dynamic
|
||||
* device identification, boards need configuration tables telling which
|
||||
* chip is at which address.
|
||||
*
|
||||
* This must be called from context that can sleep. It returns zero on
|
||||
* success, else a negative error code (dropping the master's refcount).
|
||||
* After a successful return, the caller is responsible for calling
|
||||
* spi_unregister_master().
|
||||
*/
|
||||
int __init_or_module
|
||||
spi_register_master(struct spi_master *master)
|
||||
{
|
||||
static atomic_t dyn_bus_id = ATOMIC_INIT(0);
|
||||
struct device *dev = master->cdev.dev;
|
||||
int status = -ENODEV;
|
||||
int dynamic = 0;
|
||||
|
||||
if (!dev)
|
||||
return -ENODEV;
|
||||
|
||||
/* convention: dynamically assigned bus IDs count down from the max */
|
||||
if (master->bus_num == 0) {
|
||||
master->bus_num = atomic_dec_return(&dyn_bus_id);
|
||||
dynamic = 1;
|
||||
}
|
||||
|
||||
/* register the device, then userspace will see it.
|
||||
* registration fails if the bus ID is in use.
|
||||
*/
|
||||
snprintf(master->cdev.class_id, sizeof master->cdev.class_id,
|
||||
"spi%u", master->bus_num);
|
||||
status = class_device_add(&master->cdev);
|
||||
if (status < 0)
|
||||
goto done;
|
||||
dev_dbg(dev, "registered master %s%s\n", master->cdev.class_id,
|
||||
dynamic ? " (dynamic)" : "");
|
||||
|
||||
/* populate children from any spi device tables */
|
||||
scan_boardinfo(master);
|
||||
status = 0;
|
||||
done:
|
||||
return status;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_register_master);
|
||||
|
||||
|
||||
static int __unregister(struct device *dev, void *unused)
|
||||
{
|
||||
/* note: before about 2.6.14-rc1 this would corrupt memory: */
|
||||
spi_unregister_device(to_spi_device(dev));
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_unregister_master - unregister SPI master controller
|
||||
* @master: the master being unregistered
|
||||
*
|
||||
* This call is used only by SPI master controller drivers, which are the
|
||||
* only ones directly touching chip registers.
|
||||
*
|
||||
* This must be called from context that can sleep.
|
||||
*/
|
||||
void spi_unregister_master(struct spi_master *master)
|
||||
{
|
||||
(void) device_for_each_child(master->cdev.dev, NULL, __unregister);
|
||||
class_device_unregister(&master->cdev);
|
||||
master->cdev.dev = NULL;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_unregister_master);
|
||||
|
||||
/**
|
||||
* spi_busnum_to_master - look up master associated with bus_num
|
||||
* @bus_num: the master's bus number
|
||||
*
|
||||
* This call may be used with devices that are registered after
|
||||
* arch init time. It returns a refcounted pointer to the relevant
|
||||
* spi_master (which the caller must release), or NULL if there is
|
||||
* no such master registered.
|
||||
*/
|
||||
struct spi_master *spi_busnum_to_master(u16 bus_num)
|
||||
{
|
||||
if (bus_num) {
|
||||
char name[8];
|
||||
struct kobject *bus;
|
||||
|
||||
snprintf(name, sizeof name, "spi%u", bus_num);
|
||||
bus = kset_find_obj(&spi_master_class.subsys.kset, name);
|
||||
if (bus)
|
||||
return container_of(bus, struct spi_master, cdev.kobj);
|
||||
}
|
||||
return NULL;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_busnum_to_master);
|
||||
|
||||
|
||||
/*-------------------------------------------------------------------------*/
|
||||
|
||||
static void spi_complete(void *arg)
|
||||
{
|
||||
complete(arg);
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_sync - blocking/synchronous SPI data transfers
|
||||
* @spi: device with which data will be exchanged
|
||||
* @message: describes the data transfers
|
||||
*
|
||||
* This call may only be used from a context that may sleep. The sleep
|
||||
* is non-interruptible, and has no timeout. Low-overhead controller
|
||||
* drivers may DMA directly into and out of the message buffers.
|
||||
*
|
||||
* Note that the SPI device's chip select is active during the message,
|
||||
* and then is normally disabled between messages. Drivers for some
|
||||
* frequently-used devices may want to minimize costs of selecting a chip,
|
||||
* by leaving it selected in anticipation that the next message will go
|
||||
* to the same chip. (That may increase power usage.)
|
||||
*
|
||||
* Also, the caller is guaranteeing that the memory associated with the
|
||||
* message will not be freed before this call returns.
|
||||
*
|
||||
* The return value is a negative error code if the message could not be
|
||||
* submitted, else zero. When the value is zero, then message->status is
|
||||
* also defined: it's the completion code for the transfer, either zero
|
||||
* or a negative error code from the controller driver.
|
||||
*/
|
||||
int spi_sync(struct spi_device *spi, struct spi_message *message)
|
||||
{
|
||||
DECLARE_COMPLETION(done);
|
||||
int status;
|
||||
|
||||
message->complete = spi_complete;
|
||||
message->context = &done;
|
||||
status = spi_async(spi, message);
|
||||
if (status == 0)
|
||||
wait_for_completion(&done);
|
||||
message->context = NULL;
|
||||
return status;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_sync);
|
||||
|
||||
#define SPI_BUFSIZ (SMP_CACHE_BYTES)
|
||||
|
||||
static u8 *buf;
|
||||
|
||||
/**
|
||||
* spi_write_then_read - SPI synchronous write followed by read
|
||||
* @spi: device with which data will be exchanged
|
||||
* @txbuf: data to be written (need not be dma-safe)
|
||||
* @n_tx: size of txbuf, in bytes
|
||||
* @rxbuf: buffer into which data will be read
|
||||
* @n_rx: size of rxbuf, in bytes (need not be dma-safe)
|
||||
*
|
||||
* This performs a half duplex MicroWire style transaction with the
|
||||
* device, sending txbuf and then reading rxbuf. The return value
|
||||
* is zero for success, else a negative errno status code.
|
||||
* This call may only be used from a context that may sleep.
|
||||
*
|
||||
* Parameters to this routine are always copied using a small buffer;
|
||||
* performance-sensitive or bulk transfer code should instead use
|
||||
* spi_{async,sync}() calls with dma-safe buffers.
|
||||
*/
|
||||
int spi_write_then_read(struct spi_device *spi,
|
||||
const u8 *txbuf, unsigned n_tx,
|
||||
u8 *rxbuf, unsigned n_rx)
|
||||
{
|
||||
static DECLARE_MUTEX(lock);
|
||||
|
||||
int status;
|
||||
struct spi_message message;
|
||||
struct spi_transfer x[2];
|
||||
u8 *local_buf;
|
||||
|
||||
/* Use preallocated DMA-safe buffer. We can't avoid copying here,
|
||||
* (as a pure convenience thing), but we can keep heap costs
|
||||
* out of the hot path ...
|
||||
*/
|
||||
if ((n_tx + n_rx) > SPI_BUFSIZ)
|
||||
return -EINVAL;
|
||||
|
||||
spi_message_init(&message);
|
||||
memset(x, 0, sizeof x);
|
||||
if (n_tx) {
|
||||
x[0].len = n_tx;
|
||||
spi_message_add_tail(&x[0], &message);
|
||||
}
|
||||
if (n_rx) {
|
||||
x[1].len = n_rx;
|
||||
spi_message_add_tail(&x[1], &message);
|
||||
}
|
||||
|
||||
/* ... unless someone else is using the pre-allocated buffer */
|
||||
if (down_trylock(&lock)) {
|
||||
local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
|
||||
if (!local_buf)
|
||||
return -ENOMEM;
|
||||
} else
|
||||
local_buf = buf;
|
||||
|
||||
memcpy(local_buf, txbuf, n_tx);
|
||||
x[0].tx_buf = local_buf;
|
||||
x[1].rx_buf = local_buf + n_tx;
|
||||
|
||||
/* do the i/o */
|
||||
status = spi_sync(spi, &message);
|
||||
if (status == 0) {
|
||||
memcpy(rxbuf, x[1].rx_buf, n_rx);
|
||||
status = message.status;
|
||||
}
|
||||
|
||||
if (x[0].tx_buf == buf)
|
||||
up(&lock);
|
||||
else
|
||||
kfree(local_buf);
|
||||
|
||||
return status;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_write_then_read);
|
||||
|
||||
/*-------------------------------------------------------------------------*/
|
||||
|
||||
static int __init spi_init(void)
|
||||
{
|
||||
int status;
|
||||
|
||||
buf = kmalloc(SPI_BUFSIZ, SLAB_KERNEL);
|
||||
if (!buf) {
|
||||
status = -ENOMEM;
|
||||
goto err0;
|
||||
}
|
||||
|
||||
status = bus_register(&spi_bus_type);
|
||||
if (status < 0)
|
||||
goto err1;
|
||||
|
||||
status = class_register(&spi_master_class);
|
||||
if (status < 0)
|
||||
goto err2;
|
||||
return 0;
|
||||
|
||||
err2:
|
||||
bus_unregister(&spi_bus_type);
|
||||
err1:
|
||||
kfree(buf);
|
||||
buf = NULL;
|
||||
err0:
|
||||
return status;
|
||||
}
|
||||
|
||||
/* board_info is normally registered in arch_initcall(),
|
||||
* but even essential drivers wait till later
|
||||
*
|
||||
* REVISIT only boardinfo really needs static linking. the rest (device and
|
||||
* driver registration) _could_ be dynamically linked (modular) ... costs
|
||||
* include needing to have boardinfo data structures be much more public.
|
||||
*/
|
||||
subsys_initcall(spi_init);
|
||||
|
||||
472
drivers/spi/spi_bitbang.c
Normal file
472
drivers/spi/spi_bitbang.c
Normal file
|
|
@ -0,0 +1,472 @@
|
|||
/*
|
||||
* spi_bitbang.c - polling/bitbanging SPI master controller driver utilities
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
*/
|
||||
|
||||
#include <linux/config.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/workqueue.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/errno.h>
|
||||
#include <linux/platform_device.h>
|
||||
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/spi/spi_bitbang.h>
|
||||
|
||||
|
||||
/*----------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* FIRST PART (OPTIONAL): word-at-a-time spi_transfer support.
|
||||
* Use this for GPIO or shift-register level hardware APIs.
|
||||
*
|
||||
* spi_bitbang_cs is in spi_device->controller_state, which is unavailable
|
||||
* to glue code. These bitbang setup() and cleanup() routines are always
|
||||
* used, though maybe they're called from controller-aware code.
|
||||
*
|
||||
* chipselect() and friends may use use spi_device->controller_data and
|
||||
* controller registers as appropriate.
|
||||
*
|
||||
*
|
||||
* NOTE: SPI controller pins can often be used as GPIO pins instead,
|
||||
* which means you could use a bitbang driver either to get hardware
|
||||
* working quickly, or testing for differences that aren't speed related.
|
||||
*/
|
||||
|
||||
struct spi_bitbang_cs {
|
||||
unsigned nsecs; /* (clock cycle time)/2 */
|
||||
u32 (*txrx_word)(struct spi_device *spi, unsigned nsecs,
|
||||
u32 word, u8 bits);
|
||||
unsigned (*txrx_bufs)(struct spi_device *,
|
||||
u32 (*txrx_word)(
|
||||
struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits),
|
||||
unsigned, struct spi_transfer *);
|
||||
};
|
||||
|
||||
static unsigned bitbang_txrx_8(
|
||||
struct spi_device *spi,
|
||||
u32 (*txrx_word)(struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits),
|
||||
unsigned ns,
|
||||
struct spi_transfer *t
|
||||
) {
|
||||
unsigned bits = spi->bits_per_word;
|
||||
unsigned count = t->len;
|
||||
const u8 *tx = t->tx_buf;
|
||||
u8 *rx = t->rx_buf;
|
||||
|
||||
while (likely(count > 0)) {
|
||||
u8 word = 0;
|
||||
|
||||
if (tx)
|
||||
word = *tx++;
|
||||
word = txrx_word(spi, ns, word, bits);
|
||||
if (rx)
|
||||
*rx++ = word;
|
||||
count -= 1;
|
||||
}
|
||||
return t->len - count;
|
||||
}
|
||||
|
||||
static unsigned bitbang_txrx_16(
|
||||
struct spi_device *spi,
|
||||
u32 (*txrx_word)(struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits),
|
||||
unsigned ns,
|
||||
struct spi_transfer *t
|
||||
) {
|
||||
unsigned bits = spi->bits_per_word;
|
||||
unsigned count = t->len;
|
||||
const u16 *tx = t->tx_buf;
|
||||
u16 *rx = t->rx_buf;
|
||||
|
||||
while (likely(count > 1)) {
|
||||
u16 word = 0;
|
||||
|
||||
if (tx)
|
||||
word = *tx++;
|
||||
word = txrx_word(spi, ns, word, bits);
|
||||
if (rx)
|
||||
*rx++ = word;
|
||||
count -= 2;
|
||||
}
|
||||
return t->len - count;
|
||||
}
|
||||
|
||||
static unsigned bitbang_txrx_32(
|
||||
struct spi_device *spi,
|
||||
u32 (*txrx_word)(struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits),
|
||||
unsigned ns,
|
||||
struct spi_transfer *t
|
||||
) {
|
||||
unsigned bits = spi->bits_per_word;
|
||||
unsigned count = t->len;
|
||||
const u32 *tx = t->tx_buf;
|
||||
u32 *rx = t->rx_buf;
|
||||
|
||||
while (likely(count > 3)) {
|
||||
u32 word = 0;
|
||||
|
||||
if (tx)
|
||||
word = *tx++;
|
||||
word = txrx_word(spi, ns, word, bits);
|
||||
if (rx)
|
||||
*rx++ = word;
|
||||
count -= 4;
|
||||
}
|
||||
return t->len - count;
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_bitbang_setup - default setup for per-word I/O loops
|
||||
*/
|
||||
int spi_bitbang_setup(struct spi_device *spi)
|
||||
{
|
||||
struct spi_bitbang_cs *cs = spi->controller_state;
|
||||
struct spi_bitbang *bitbang;
|
||||
|
||||
if (!spi->max_speed_hz)
|
||||
return -EINVAL;
|
||||
|
||||
if (!cs) {
|
||||
cs = kzalloc(sizeof *cs, SLAB_KERNEL);
|
||||
if (!cs)
|
||||
return -ENOMEM;
|
||||
spi->controller_state = cs;
|
||||
}
|
||||
bitbang = spi_master_get_devdata(spi->master);
|
||||
|
||||
if (!spi->bits_per_word)
|
||||
spi->bits_per_word = 8;
|
||||
|
||||
/* spi_transfer level calls that work per-word */
|
||||
if (spi->bits_per_word <= 8)
|
||||
cs->txrx_bufs = bitbang_txrx_8;
|
||||
else if (spi->bits_per_word <= 16)
|
||||
cs->txrx_bufs = bitbang_txrx_16;
|
||||
else if (spi->bits_per_word <= 32)
|
||||
cs->txrx_bufs = bitbang_txrx_32;
|
||||
else
|
||||
return -EINVAL;
|
||||
|
||||
/* per-word shift register access, in hardware or bitbanging */
|
||||
cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
|
||||
if (!cs->txrx_word)
|
||||
return -EINVAL;
|
||||
|
||||
/* nsecs = (clock period)/2 */
|
||||
cs->nsecs = (1000000000/2) / (spi->max_speed_hz);
|
||||
if (cs->nsecs > MAX_UDELAY_MS * 1000)
|
||||
return -EINVAL;
|
||||
|
||||
dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
|
||||
__FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
|
||||
spi->bits_per_word, 2 * cs->nsecs);
|
||||
|
||||
/* NOTE we _need_ to call chipselect() early, ideally with adapter
|
||||
* setup, unless the hardware defaults cooperate to avoid confusion
|
||||
* between normal (active low) and inverted chipselects.
|
||||
*/
|
||||
|
||||
/* deselect chip (low or high) */
|
||||
spin_lock(&bitbang->lock);
|
||||
if (!bitbang->busy) {
|
||||
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
|
||||
ndelay(cs->nsecs);
|
||||
}
|
||||
spin_unlock(&bitbang->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_bitbang_setup);
|
||||
|
||||
/**
|
||||
* spi_bitbang_cleanup - default cleanup for per-word I/O loops
|
||||
*/
|
||||
void spi_bitbang_cleanup(const struct spi_device *spi)
|
||||
{
|
||||
kfree(spi->controller_state);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_bitbang_cleanup);
|
||||
|
||||
static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
|
||||
{
|
||||
struct spi_bitbang_cs *cs = spi->controller_state;
|
||||
unsigned nsecs = cs->nsecs;
|
||||
|
||||
return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
|
||||
}
|
||||
|
||||
/*----------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* SECOND PART ... simple transfer queue runner.
|
||||
*
|
||||
* This costs a task context per controller, running the queue by
|
||||
* performing each transfer in sequence. Smarter hardware can queue
|
||||
* several DMA transfers at once, and process several controller queues
|
||||
* in parallel; this driver doesn't match such hardware very well.
|
||||
*
|
||||
* Drivers can provide word-at-a-time i/o primitives, or provide
|
||||
* transfer-at-a-time ones to leverage dma or fifo hardware.
|
||||
*/
|
||||
static void bitbang_work(void *_bitbang)
|
||||
{
|
||||
struct spi_bitbang *bitbang = _bitbang;
|
||||
unsigned long flags;
|
||||
|
||||
spin_lock_irqsave(&bitbang->lock, flags);
|
||||
bitbang->busy = 1;
|
||||
while (!list_empty(&bitbang->queue)) {
|
||||
struct spi_message *m;
|
||||
struct spi_device *spi;
|
||||
unsigned nsecs;
|
||||
struct spi_transfer *t = NULL;
|
||||
unsigned tmp;
|
||||
unsigned cs_change;
|
||||
int status;
|
||||
|
||||
m = container_of(bitbang->queue.next, struct spi_message,
|
||||
queue);
|
||||
list_del_init(&m->queue);
|
||||
spin_unlock_irqrestore(&bitbang->lock, flags);
|
||||
|
||||
/* FIXME this is made-up ... the correct value is known to
|
||||
* word-at-a-time bitbang code, and presumably chipselect()
|
||||
* should enforce these requirements too?
|
||||
*/
|
||||
nsecs = 100;
|
||||
|
||||
spi = m->spi;
|
||||
tmp = 0;
|
||||
cs_change = 1;
|
||||
status = 0;
|
||||
|
||||
list_for_each_entry (t, &m->transfers, transfer_list) {
|
||||
if (bitbang->shutdown) {
|
||||
status = -ESHUTDOWN;
|
||||
break;
|
||||
}
|
||||
|
||||
/* set up default clock polarity, and activate chip;
|
||||
* this implicitly updates clock and spi modes as
|
||||
* previously recorded for this device via setup().
|
||||
* (and also deselects any other chip that might be
|
||||
* selected ...)
|
||||
*/
|
||||
if (cs_change) {
|
||||
bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
|
||||
ndelay(nsecs);
|
||||
}
|
||||
cs_change = t->cs_change;
|
||||
if (!t->tx_buf && !t->rx_buf && t->len) {
|
||||
status = -EINVAL;
|
||||
break;
|
||||
}
|
||||
|
||||
/* transfer data. the lower level code handles any
|
||||
* new dma mappings it needs. our caller always gave
|
||||
* us dma-safe buffers.
|
||||
*/
|
||||
if (t->len) {
|
||||
/* REVISIT dma API still needs a designated
|
||||
* DMA_ADDR_INVALID; ~0 might be better.
|
||||
*/
|
||||
if (!m->is_dma_mapped)
|
||||
t->rx_dma = t->tx_dma = 0;
|
||||
status = bitbang->txrx_bufs(spi, t);
|
||||
}
|
||||
if (status != t->len) {
|
||||
if (status > 0)
|
||||
status = -EMSGSIZE;
|
||||
break;
|
||||
}
|
||||
m->actual_length += status;
|
||||
status = 0;
|
||||
|
||||
/* protocol tweaks before next transfer */
|
||||
if (t->delay_usecs)
|
||||
udelay(t->delay_usecs);
|
||||
|
||||
if (!cs_change)
|
||||
continue;
|
||||
if (t->transfer_list.next == &m->transfers)
|
||||
break;
|
||||
|
||||
/* sometimes a short mid-message deselect of the chip
|
||||
* may be needed to terminate a mode or command
|
||||
*/
|
||||
ndelay(nsecs);
|
||||
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
|
||||
ndelay(nsecs);
|
||||
}
|
||||
|
||||
m->status = status;
|
||||
m->complete(m->context);
|
||||
|
||||
/* normally deactivate chipselect ... unless no error and
|
||||
* cs_change has hinted that the next message will probably
|
||||
* be for this chip too.
|
||||
*/
|
||||
if (!(status == 0 && cs_change)) {
|
||||
ndelay(nsecs);
|
||||
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
|
||||
ndelay(nsecs);
|
||||
}
|
||||
|
||||
spin_lock_irqsave(&bitbang->lock, flags);
|
||||
}
|
||||
bitbang->busy = 0;
|
||||
spin_unlock_irqrestore(&bitbang->lock, flags);
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_bitbang_transfer - default submit to transfer queue
|
||||
*/
|
||||
int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
|
||||
{
|
||||
struct spi_bitbang *bitbang;
|
||||
unsigned long flags;
|
||||
|
||||
m->actual_length = 0;
|
||||
m->status = -EINPROGRESS;
|
||||
|
||||
bitbang = spi_master_get_devdata(spi->master);
|
||||
if (bitbang->shutdown)
|
||||
return -ESHUTDOWN;
|
||||
|
||||
spin_lock_irqsave(&bitbang->lock, flags);
|
||||
list_add_tail(&m->queue, &bitbang->queue);
|
||||
queue_work(bitbang->workqueue, &bitbang->work);
|
||||
spin_unlock_irqrestore(&bitbang->lock, flags);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
|
||||
|
||||
/*----------------------------------------------------------------------*/
|
||||
|
||||
/**
|
||||
* spi_bitbang_start - start up a polled/bitbanging SPI master driver
|
||||
* @bitbang: driver handle
|
||||
*
|
||||
* Caller should have zero-initialized all parts of the structure, and then
|
||||
* provided callbacks for chip selection and I/O loops. If the master has
|
||||
* a transfer method, its final step should call spi_bitbang_transfer; or,
|
||||
* that's the default if the transfer routine is not initialized. It should
|
||||
* also set up the bus number and number of chipselects.
|
||||
*
|
||||
* For i/o loops, provide callbacks either per-word (for bitbanging, or for
|
||||
* hardware that basically exposes a shift register) or per-spi_transfer
|
||||
* (which takes better advantage of hardware like fifos or DMA engines).
|
||||
*
|
||||
* Drivers using per-word I/O loops should use (or call) spi_bitbang_setup and
|
||||
* spi_bitbang_cleanup to handle those spi master methods. Those methods are
|
||||
* the defaults if the bitbang->txrx_bufs routine isn't initialized.
|
||||
*
|
||||
* This routine registers the spi_master, which will process requests in a
|
||||
* dedicated task, keeping IRQs unblocked most of the time. To stop
|
||||
* processing those requests, call spi_bitbang_stop().
|
||||
*/
|
||||
int spi_bitbang_start(struct spi_bitbang *bitbang)
|
||||
{
|
||||
int status;
|
||||
|
||||
if (!bitbang->master || !bitbang->chipselect)
|
||||
return -EINVAL;
|
||||
|
||||
INIT_WORK(&bitbang->work, bitbang_work, bitbang);
|
||||
spin_lock_init(&bitbang->lock);
|
||||
INIT_LIST_HEAD(&bitbang->queue);
|
||||
|
||||
if (!bitbang->master->transfer)
|
||||
bitbang->master->transfer = spi_bitbang_transfer;
|
||||
if (!bitbang->txrx_bufs) {
|
||||
bitbang->use_dma = 0;
|
||||
bitbang->txrx_bufs = spi_bitbang_bufs;
|
||||
if (!bitbang->master->setup) {
|
||||
bitbang->master->setup = spi_bitbang_setup;
|
||||
bitbang->master->cleanup = spi_bitbang_cleanup;
|
||||
}
|
||||
} else if (!bitbang->master->setup)
|
||||
return -EINVAL;
|
||||
|
||||
/* this task is the only thing to touch the SPI bits */
|
||||
bitbang->busy = 0;
|
||||
bitbang->workqueue = create_singlethread_workqueue(
|
||||
bitbang->master->cdev.dev->bus_id);
|
||||
if (bitbang->workqueue == NULL) {
|
||||
status = -EBUSY;
|
||||
goto err1;
|
||||
}
|
||||
|
||||
/* driver may get busy before register() returns, especially
|
||||
* if someone registered boardinfo for devices
|
||||
*/
|
||||
status = spi_register_master(bitbang->master);
|
||||
if (status < 0)
|
||||
goto err2;
|
||||
|
||||
return status;
|
||||
|
||||
err2:
|
||||
destroy_workqueue(bitbang->workqueue);
|
||||
err1:
|
||||
return status;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_bitbang_start);
|
||||
|
||||
/**
|
||||
* spi_bitbang_stop - stops the task providing spi communication
|
||||
*/
|
||||
int spi_bitbang_stop(struct spi_bitbang *bitbang)
|
||||
{
|
||||
unsigned limit = 500;
|
||||
|
||||
spin_lock_irq(&bitbang->lock);
|
||||
bitbang->shutdown = 0;
|
||||
while (!list_empty(&bitbang->queue) && limit--) {
|
||||
spin_unlock_irq(&bitbang->lock);
|
||||
|
||||
dev_dbg(bitbang->master->cdev.dev, "wait for queue\n");
|
||||
msleep(10);
|
||||
|
||||
spin_lock_irq(&bitbang->lock);
|
||||
}
|
||||
spin_unlock_irq(&bitbang->lock);
|
||||
if (!list_empty(&bitbang->queue)) {
|
||||
dev_err(bitbang->master->cdev.dev, "queue didn't empty\n");
|
||||
return -EBUSY;
|
||||
}
|
||||
|
||||
destroy_workqueue(bitbang->workqueue);
|
||||
|
||||
spi_unregister_master(bitbang->master);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(spi_bitbang_stop);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
|
||||
423
drivers/spi/spi_butterfly.c
Normal file
423
drivers/spi/spi_butterfly.c
Normal file
|
|
@ -0,0 +1,423 @@
|
|||
/*
|
||||
* spi_butterfly.c - parport-to-butterfly adapter
|
||||
*
|
||||
* Copyright (C) 2005 David Brownell
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
#include <linux/config.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/parport.h>
|
||||
|
||||
#include <linux/spi/spi.h>
|
||||
#include <linux/spi/spi_bitbang.h>
|
||||
#include <linux/spi/flash.h>
|
||||
|
||||
#include <linux/mtd/partitions.h>
|
||||
|
||||
|
||||
/*
|
||||
* This uses SPI to talk with an "AVR Butterfly", which is a $US20 card
|
||||
* with a battery powered AVR microcontroller and lots of goodies. You
|
||||
* can use GCC to develop firmware for this.
|
||||
*
|
||||
* See Documentation/spi/butterfly for information about how to build
|
||||
* and use this custom parallel port cable.
|
||||
*/
|
||||
|
||||
#undef HAVE_USI /* nyet */
|
||||
|
||||
|
||||
/* DATA output bits (pins 2..9 == D0..D7) */
|
||||
#define butterfly_nreset (1 << 1) /* pin 3 */
|
||||
|
||||
#define spi_sck_bit (1 << 0) /* pin 2 */
|
||||
#define spi_mosi_bit (1 << 7) /* pin 9 */
|
||||
|
||||
#define usi_sck_bit (1 << 3) /* pin 5 */
|
||||
#define usi_mosi_bit (1 << 4) /* pin 6 */
|
||||
|
||||
#define vcc_bits ((1 << 6) | (1 << 5)) /* pins 7, 8 */
|
||||
|
||||
/* STATUS input bits */
|
||||
#define spi_miso_bit PARPORT_STATUS_BUSY /* pin 11 */
|
||||
|
||||
#define usi_miso_bit PARPORT_STATUS_PAPEROUT /* pin 12 */
|
||||
|
||||
/* CONTROL output bits */
|
||||
#define spi_cs_bit PARPORT_CONTROL_SELECT /* pin 17 */
|
||||
/* USI uses no chipselect */
|
||||
|
||||
|
||||
|
||||
static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
|
||||
{
|
||||
return spi->controller_data;
|
||||
}
|
||||
|
||||
static inline int is_usidev(struct spi_device *spi)
|
||||
{
|
||||
#ifdef HAVE_USI
|
||||
return spi->chip_select != 1;
|
||||
#else
|
||||
return 0;
|
||||
#endif
|
||||
}
|
||||
|
||||
|
||||
struct butterfly {
|
||||
/* REVISIT ... for now, this must be first */
|
||||
struct spi_bitbang bitbang;
|
||||
|
||||
struct parport *port;
|
||||
struct pardevice *pd;
|
||||
|
||||
u8 lastbyte;
|
||||
|
||||
struct spi_device *dataflash;
|
||||
struct spi_device *butterfly;
|
||||
struct spi_board_info info[2];
|
||||
|
||||
};
|
||||
|
||||
/*----------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* these routines may be slower than necessary because they're hiding
|
||||
* the fact that there are two different SPI busses on this cable: one
|
||||
* to the DataFlash chip (or AVR SPI controller), the other to the
|
||||
* AVR USI controller.
|
||||
*/
|
||||
|
||||
static inline void
|
||||
setsck(struct spi_device *spi, int is_on)
|
||||
{
|
||||
struct butterfly *pp = spidev_to_pp(spi);
|
||||
u8 bit, byte = pp->lastbyte;
|
||||
|
||||
if (is_usidev(spi))
|
||||
bit = usi_sck_bit;
|
||||
else
|
||||
bit = spi_sck_bit;
|
||||
|
||||
if (is_on)
|
||||
byte |= bit;
|
||||
else
|
||||
byte &= ~bit;
|
||||
parport_write_data(pp->port, byte);
|
||||
pp->lastbyte = byte;
|
||||
}
|
||||
|
||||
static inline void
|
||||
setmosi(struct spi_device *spi, int is_on)
|
||||
{
|
||||
struct butterfly *pp = spidev_to_pp(spi);
|
||||
u8 bit, byte = pp->lastbyte;
|
||||
|
||||
if (is_usidev(spi))
|
||||
bit = usi_mosi_bit;
|
||||
else
|
||||
bit = spi_mosi_bit;
|
||||
|
||||
if (is_on)
|
||||
byte |= bit;
|
||||
else
|
||||
byte &= ~bit;
|
||||
parport_write_data(pp->port, byte);
|
||||
pp->lastbyte = byte;
|
||||
}
|
||||
|
||||
static inline int getmiso(struct spi_device *spi)
|
||||
{
|
||||
struct butterfly *pp = spidev_to_pp(spi);
|
||||
int value;
|
||||
u8 bit;
|
||||
|
||||
if (is_usidev(spi))
|
||||
bit = usi_miso_bit;
|
||||
else
|
||||
bit = spi_miso_bit;
|
||||
|
||||
/* only STATUS_BUSY is NOT negated */
|
||||
value = !(parport_read_status(pp->port) & bit);
|
||||
return (bit == PARPORT_STATUS_BUSY) ? value : !value;
|
||||
}
|
||||
|
||||
static void butterfly_chipselect(struct spi_device *spi, int value)
|
||||
{
|
||||
struct butterfly *pp = spidev_to_pp(spi);
|
||||
|
||||
/* set default clock polarity */
|
||||
if (value)
|
||||
setsck(spi, spi->mode & SPI_CPOL);
|
||||
|
||||
/* no chipselect on this USI link config */
|
||||
if (is_usidev(spi))
|
||||
return;
|
||||
|
||||
/* here, value == "activate or not" */
|
||||
|
||||
/* most PARPORT_CONTROL_* bits are negated */
|
||||
if (spi_cs_bit == PARPORT_CONTROL_INIT)
|
||||
value = !value;
|
||||
|
||||
/* here, value == "bit value to write in control register" */
|
||||
|
||||
parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0);
|
||||
}
|
||||
|
||||
|
||||
/* we only needed to implement one mode here, and choose SPI_MODE_0 */
|
||||
|
||||
#define spidelay(X) do{}while(0)
|
||||
//#define spidelay ndelay
|
||||
|
||||
#define EXPAND_BITBANG_TXRX
|
||||
#include <linux/spi/spi_bitbang.h>
|
||||
|
||||
static u32
|
||||
butterfly_txrx_word_mode0(struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits)
|
||||
{
|
||||
return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
|
||||
}
|
||||
|
||||
/*----------------------------------------------------------------------*/
|
||||
|
||||
/* override default partitioning with cmdlinepart */
|
||||
static struct mtd_partition partitions[] = { {
|
||||
/* JFFS2 wants partitions of 4*N blocks for this device ... */
|
||||
|
||||
/* sector 0 = 8 pages * 264 bytes/page (1 block)
|
||||
* sector 1 = 248 pages * 264 bytes/page
|
||||
*/
|
||||
.name = "bookkeeping", // 66 KB
|
||||
.offset = 0,
|
||||
.size = (8 + 248) * 264,
|
||||
// .mask_flags = MTD_WRITEABLE,
|
||||
}, {
|
||||
/* sector 2 = 256 pages * 264 bytes/page
|
||||
* sectors 3-5 = 512 pages * 264 bytes/page
|
||||
*/
|
||||
.name = "filesystem", // 462 KB
|
||||
.offset = MTDPART_OFS_APPEND,
|
||||
.size = MTDPART_SIZ_FULL,
|
||||
} };
|
||||
|
||||
static struct flash_platform_data flash = {
|
||||
.name = "butterflash",
|
||||
.parts = partitions,
|
||||
.nr_parts = ARRAY_SIZE(partitions),
|
||||
};
|
||||
|
||||
|
||||
/* REVISIT remove this ugly global and its "only one" limitation */
|
||||
static struct butterfly *butterfly;
|
||||
|
||||
static void butterfly_attach(struct parport *p)
|
||||
{
|
||||
struct pardevice *pd;
|
||||
int status;
|
||||
struct butterfly *pp;
|
||||
struct spi_master *master;
|
||||
struct platform_device *pdev;
|
||||
|
||||
if (butterfly)
|
||||
return;
|
||||
|
||||
/* REVISIT: this just _assumes_ a butterfly is there ... no probe,
|
||||
* and no way to be selective about what it binds to.
|
||||
*/
|
||||
|
||||
/* FIXME where should master->cdev.dev come from?
|
||||
* e.g. /sys/bus/pnp0/00:0b, some PCI thing, etc
|
||||
* setting up a platform device like this is an ugly kluge...
|
||||
*/
|
||||
pdev = platform_device_register_simple("butterfly", -1, NULL, 0);
|
||||
|
||||
master = spi_alloc_master(&pdev->dev, sizeof *pp);
|
||||
if (!master) {
|
||||
status = -ENOMEM;
|
||||
goto done;
|
||||
}
|
||||
pp = spi_master_get_devdata(master);
|
||||
|
||||
/*
|
||||
* SPI and bitbang hookup
|
||||
*
|
||||
* use default setup(), cleanup(), and transfer() methods; and
|
||||
* only bother implementing mode 0. Start it later.
|
||||
*/
|
||||
master->bus_num = 42;
|
||||
master->num_chipselect = 2;
|
||||
|
||||
pp->bitbang.master = spi_master_get(master);
|
||||
pp->bitbang.chipselect = butterfly_chipselect;
|
||||
pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
|
||||
|
||||
/*
|
||||
* parport hookup
|
||||
*/
|
||||
pp->port = p;
|
||||
pd = parport_register_device(p, "spi_butterfly",
|
||||
NULL, NULL, NULL,
|
||||
0 /* FLAGS */, pp);
|
||||
if (!pd) {
|
||||
status = -ENOMEM;
|
||||
goto clean0;
|
||||
}
|
||||
pp->pd = pd;
|
||||
|
||||
status = parport_claim(pd);
|
||||
if (status < 0)
|
||||
goto clean1;
|
||||
|
||||
/*
|
||||
* Butterfly reset, powerup, run firmware
|
||||
*/
|
||||
pr_debug("%s: powerup/reset Butterfly\n", p->name);
|
||||
|
||||
/* nCS for dataflash (this bit is inverted on output) */
|
||||
parport_frob_control(pp->port, spi_cs_bit, 0);
|
||||
|
||||
/* stabilize power with chip in reset (nRESET), and
|
||||
* both spi_sck_bit and usi_sck_bit clear (CPOL=0)
|
||||
*/
|
||||
pp->lastbyte |= vcc_bits;
|
||||
parport_write_data(pp->port, pp->lastbyte);
|
||||
msleep(5);
|
||||
|
||||
/* take it out of reset; assume long reset delay */
|
||||
pp->lastbyte |= butterfly_nreset;
|
||||
parport_write_data(pp->port, pp->lastbyte);
|
||||
msleep(100);
|
||||
|
||||
|
||||
/*
|
||||
* Start SPI ... for now, hide that we're two physical busses.
|
||||
*/
|
||||
status = spi_bitbang_start(&pp->bitbang);
|
||||
if (status < 0)
|
||||
goto clean2;
|
||||
|
||||
/* Bus 1 lets us talk to at45db041b (firmware disables AVR)
|
||||
* or AVR (firmware resets at45, acts as spi slave)
|
||||
*/
|
||||
pp->info[0].max_speed_hz = 15 * 1000 * 1000;
|
||||
strcpy(pp->info[0].modalias, "mtd_dataflash");
|
||||
pp->info[0].platform_data = &flash;
|
||||
pp->info[0].chip_select = 1;
|
||||
pp->info[0].controller_data = pp;
|
||||
pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]);
|
||||
if (pp->dataflash)
|
||||
pr_debug("%s: dataflash at %s\n", p->name,
|
||||
pp->dataflash->dev.bus_id);
|
||||
|
||||
#ifdef HAVE_USI
|
||||
/* even more custom AVR firmware */
|
||||
pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000;
|
||||
strcpy(pp->info[1].modalias, "butterfly");
|
||||
// pp->info[1].platform_data = ... TBD ... ;
|
||||
pp->info[1].chip_select = 2,
|
||||
pp->info[1].controller_data = pp;
|
||||
pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[1]);
|
||||
if (pp->butterfly)
|
||||
pr_debug("%s: butterfly at %s\n", p->name,
|
||||
pp->butterfly->dev.bus_id);
|
||||
|
||||
/* FIXME setup ACK for the IRQ line ... */
|
||||
#endif
|
||||
|
||||
// dev_info(_what?_, ...)
|
||||
pr_info("%s: AVR Butterfly\n", p->name);
|
||||
butterfly = pp;
|
||||
return;
|
||||
|
||||
clean2:
|
||||
/* turn off VCC */
|
||||
parport_write_data(pp->port, 0);
|
||||
|
||||
parport_release(pp->pd);
|
||||
clean1:
|
||||
parport_unregister_device(pd);
|
||||
clean0:
|
||||
(void) spi_master_put(pp->bitbang.master);
|
||||
done:
|
||||
platform_device_unregister(pdev);
|
||||
pr_debug("%s: butterfly probe, fail %d\n", p->name, status);
|
||||
}
|
||||
|
||||
static void butterfly_detach(struct parport *p)
|
||||
{
|
||||
struct butterfly *pp;
|
||||
struct platform_device *pdev;
|
||||
int status;
|
||||
|
||||
/* FIXME this global is ugly ... but, how to quickly get from
|
||||
* the parport to the "struct butterfly" associated with it?
|
||||
* "old school" driver-internal device lists?
|
||||
*/
|
||||
if (!butterfly || butterfly->port != p)
|
||||
return;
|
||||
pp = butterfly;
|
||||
butterfly = NULL;
|
||||
|
||||
#ifdef HAVE_USI
|
||||
spi_unregister_device(pp->butterfly);
|
||||
pp->butterfly = NULL;
|
||||
#endif
|
||||
spi_unregister_device(pp->dataflash);
|
||||
pp->dataflash = NULL;
|
||||
|
||||
status = spi_bitbang_stop(&pp->bitbang);
|
||||
|
||||
/* turn off VCC */
|
||||
parport_write_data(pp->port, 0);
|
||||
msleep(10);
|
||||
|
||||
parport_release(pp->pd);
|
||||
parport_unregister_device(pp->pd);
|
||||
|
||||
pdev = to_platform_device(pp->bitbang.master->cdev.dev);
|
||||
|
||||
(void) spi_master_put(pp->bitbang.master);
|
||||
|
||||
platform_device_unregister(pdev);
|
||||
}
|
||||
|
||||
static struct parport_driver butterfly_driver = {
|
||||
.name = "spi_butterfly",
|
||||
.attach = butterfly_attach,
|
||||
.detach = butterfly_detach,
|
||||
};
|
||||
|
||||
|
||||
static int __init butterfly_init(void)
|
||||
{
|
||||
return parport_register_driver(&butterfly_driver);
|
||||
}
|
||||
device_initcall(butterfly_init);
|
||||
|
||||
static void __exit butterfly_exit(void)
|
||||
{
|
||||
parport_unregister_driver(&butterfly_driver);
|
||||
}
|
||||
module_exit(butterfly_exit);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
18
include/linux/spi/ads7846.h
Normal file
18
include/linux/spi/ads7846.h
Normal file
|
|
@ -0,0 +1,18 @@
|
|||
/* linux/spi/ads7846.h */
|
||||
|
||||
/* Touchscreen characteristics vary between boards and models. The
|
||||
* platform_data for the device's "struct device" holds this information.
|
||||
*
|
||||
* It's OK if the min/max values are zero.
|
||||
*/
|
||||
struct ads7846_platform_data {
|
||||
u16 model; /* 7843, 7845, 7846. */
|
||||
u16 vref_delay_usecs; /* 0 for external vref; etc */
|
||||
u16 x_plate_ohms;
|
||||
u16 y_plate_ohms;
|
||||
|
||||
u16 x_min, x_max;
|
||||
u16 y_min, y_max;
|
||||
u16 pressure_min, pressure_max;
|
||||
};
|
||||
|
||||
31
include/linux/spi/flash.h
Normal file
31
include/linux/spi/flash.h
Normal file
|
|
@ -0,0 +1,31 @@
|
|||
#ifndef LINUX_SPI_FLASH_H
|
||||
#define LINUX_SPI_FLASH_H
|
||||
|
||||
struct mtd_partition;
|
||||
|
||||
/**
|
||||
* struct flash_platform_data: board-specific flash data
|
||||
* @name: optional flash device name (eg, as used with mtdparts=)
|
||||
* @parts: optional array of mtd_partitions for static partitioning
|
||||
* @nr_parts: number of mtd_partitions for static partitoning
|
||||
* @type: optional flash device type (e.g. m25p80 vs m25p64), for use
|
||||
* with chips that can't be queried for JEDEC or other IDs
|
||||
*
|
||||
* Board init code (in arch/.../mach-xxx/board-yyy.c files) can
|
||||
* provide information about SPI flash parts (such as DataFlash) to
|
||||
* help set up the device and its appropriate default partitioning.
|
||||
*
|
||||
* Note that for DataFlash, sizes for pages, blocks, and sectors are
|
||||
* rarely powers of two; and partitions should be sector-aligned.
|
||||
*/
|
||||
struct flash_platform_data {
|
||||
char *name;
|
||||
struct mtd_partition *parts;
|
||||
unsigned int nr_parts;
|
||||
|
||||
char *type;
|
||||
|
||||
/* we'll likely add more ... use JEDEC IDs, etc */
|
||||
};
|
||||
|
||||
#endif
|
||||
668
include/linux/spi/spi.h
Normal file
668
include/linux/spi/spi.h
Normal file
|
|
@ -0,0 +1,668 @@
|
|||
/*
|
||||
* Copyright (C) 2005 David Brownell
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
#ifndef __LINUX_SPI_H
|
||||
#define __LINUX_SPI_H
|
||||
|
||||
/*
|
||||
* INTERFACES between SPI master-side drivers and SPI infrastructure.
|
||||
* (There's no SPI slave support for Linux yet...)
|
||||
*/
|
||||
extern struct bus_type spi_bus_type;
|
||||
|
||||
/**
|
||||
* struct spi_device - Master side proxy for an SPI slave device
|
||||
* @dev: Driver model representation of the device.
|
||||
* @master: SPI controller used with the device.
|
||||
* @max_speed_hz: Maximum clock rate to be used with this chip
|
||||
* (on this board); may be changed by the device's driver.
|
||||
* @chip-select: Chipselect, distinguishing chips handled by "master".
|
||||
* @mode: The spi mode defines how data is clocked out and in.
|
||||
* This may be changed by the device's driver.
|
||||
* @bits_per_word: Data transfers involve one or more words; word sizes
|
||||
* like eight or 12 bits are common. In-memory wordsizes are
|
||||
* powers of two bytes (e.g. 20 bit samples use 32 bits).
|
||||
* This may be changed by the device's driver.
|
||||
* @irq: Negative, or the number passed to request_irq() to receive
|
||||
* interrupts from this device.
|
||||
* @controller_state: Controller's runtime state
|
||||
* @controller_data: Board-specific definitions for controller, such as
|
||||
* FIFO initialization parameters; from board_info.controller_data
|
||||
*
|
||||
* An spi_device is used to interchange data between an SPI slave
|
||||
* (usually a discrete chip) and CPU memory.
|
||||
*
|
||||
* In "dev", the platform_data is used to hold information about this
|
||||
* device that's meaningful to the device's protocol driver, but not
|
||||
* to its controller. One example might be an identifier for a chip
|
||||
* variant with slightly different functionality.
|
||||
*/
|
||||
struct spi_device {
|
||||
struct device dev;
|
||||
struct spi_master *master;
|
||||
u32 max_speed_hz;
|
||||
u8 chip_select;
|
||||
u8 mode;
|
||||
#define SPI_CPHA 0x01 /* clock phase */
|
||||
#define SPI_CPOL 0x02 /* clock polarity */
|
||||
#define SPI_MODE_0 (0|0) /* (original MicroWire) */
|
||||
#define SPI_MODE_1 (0|SPI_CPHA)
|
||||
#define SPI_MODE_2 (SPI_CPOL|0)
|
||||
#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
|
||||
#define SPI_CS_HIGH 0x04 /* chipselect active high? */
|
||||
u8 bits_per_word;
|
||||
int irq;
|
||||
void *controller_state;
|
||||
void *controller_data;
|
||||
const char *modalias;
|
||||
|
||||
// likely need more hooks for more protocol options affecting how
|
||||
// the controller talks to each chip, like:
|
||||
// - bit order (default is wordwise msb-first)
|
||||
// - memory packing (12 bit samples into low bits, others zeroed)
|
||||
// - priority
|
||||
// - drop chipselect after each word
|
||||
// - chipselect delays
|
||||
// - ...
|
||||
};
|
||||
|
||||
static inline struct spi_device *to_spi_device(struct device *dev)
|
||||
{
|
||||
return dev ? container_of(dev, struct spi_device, dev) : NULL;
|
||||
}
|
||||
|
||||
/* most drivers won't need to care about device refcounting */
|
||||
static inline struct spi_device *spi_dev_get(struct spi_device *spi)
|
||||
{
|
||||
return (spi && get_device(&spi->dev)) ? spi : NULL;
|
||||
}
|
||||
|
||||
static inline void spi_dev_put(struct spi_device *spi)
|
||||
{
|
||||
if (spi)
|
||||
put_device(&spi->dev);
|
||||
}
|
||||
|
||||
/* ctldata is for the bus_master driver's runtime state */
|
||||
static inline void *spi_get_ctldata(struct spi_device *spi)
|
||||
{
|
||||
return spi->controller_state;
|
||||
}
|
||||
|
||||
static inline void spi_set_ctldata(struct spi_device *spi, void *state)
|
||||
{
|
||||
spi->controller_state = state;
|
||||
}
|
||||
|
||||
|
||||
struct spi_message;
|
||||
|
||||
|
||||
|
||||
struct spi_driver {
|
||||
int (*probe)(struct spi_device *spi);
|
||||
int (*remove)(struct spi_device *spi);
|
||||
void (*shutdown)(struct spi_device *spi);
|
||||
int (*suspend)(struct spi_device *spi, pm_message_t mesg);
|
||||
int (*resume)(struct spi_device *spi);
|
||||
struct device_driver driver;
|
||||
};
|
||||
|
||||
static inline struct spi_driver *to_spi_driver(struct device_driver *drv)
|
||||
{
|
||||
return drv ? container_of(drv, struct spi_driver, driver) : NULL;
|
||||
}
|
||||
|
||||
extern int spi_register_driver(struct spi_driver *sdrv);
|
||||
|
||||
static inline void spi_unregister_driver(struct spi_driver *sdrv)
|
||||
{
|
||||
if (!sdrv)
|
||||
return;
|
||||
driver_unregister(&sdrv->driver);
|
||||
}
|
||||
|
||||
|
||||
|
||||
/**
|
||||
* struct spi_master - interface to SPI master controller
|
||||
* @cdev: class interface to this driver
|
||||
* @bus_num: board-specific (and often SOC-specific) identifier for a
|
||||
* given SPI controller.
|
||||
* @num_chipselect: chipselects are used to distinguish individual
|
||||
* SPI slaves, and are numbered from zero to num_chipselects.
|
||||
* each slave has a chipselect signal, but it's common that not
|
||||
* every chipselect is connected to a slave.
|
||||
* @setup: updates the device mode and clocking records used by a
|
||||
* device's SPI controller; protocol code may call this.
|
||||
* @transfer: adds a message to the controller's transfer queue.
|
||||
* @cleanup: frees controller-specific state
|
||||
*
|
||||
* Each SPI master controller can communicate with one or more spi_device
|
||||
* children. These make a small bus, sharing MOSI, MISO and SCK signals
|
||||
* but not chip select signals. Each device may be configured to use a
|
||||
* different clock rate, since those shared signals are ignored unless
|
||||
* the chip is selected.
|
||||
*
|
||||
* The driver for an SPI controller manages access to those devices through
|
||||
* a queue of spi_message transactions, copyin data between CPU memory and
|
||||
* an SPI slave device). For each such message it queues, it calls the
|
||||
* message's completion function when the transaction completes.
|
||||
*/
|
||||
struct spi_master {
|
||||
struct class_device cdev;
|
||||
|
||||
/* other than zero (== assign one dynamically), bus_num is fully
|
||||
* board-specific. usually that simplifies to being SOC-specific.
|
||||
* example: one SOC has three SPI controllers, numbered 1..3,
|
||||
* and one board's schematics might show it using SPI-2. software
|
||||
* would normally use bus_num=2 for that controller.
|
||||
*/
|
||||
u16 bus_num;
|
||||
|
||||
/* chipselects will be integral to many controllers; some others
|
||||
* might use board-specific GPIOs.
|
||||
*/
|
||||
u16 num_chipselect;
|
||||
|
||||
/* setup mode and clock, etc (spi driver may call many times) */
|
||||
int (*setup)(struct spi_device *spi);
|
||||
|
||||
/* bidirectional bulk transfers
|
||||
*
|
||||
* + The transfer() method may not sleep; its main role is
|
||||
* just to add the message to the queue.
|
||||
* + For now there's no remove-from-queue operation, or
|
||||
* any other request management
|
||||
* + To a given spi_device, message queueing is pure fifo
|
||||
*
|
||||
* + The master's main job is to process its message queue,
|
||||
* selecting a chip then transferring data
|
||||
* + If there are multiple spi_device children, the i/o queue
|
||||
* arbitration algorithm is unspecified (round robin, fifo,
|
||||
* priority, reservations, preemption, etc)
|
||||
*
|
||||
* + Chipselect stays active during the entire message
|
||||
* (unless modified by spi_transfer.cs_change != 0).
|
||||
* + The message transfers use clock and SPI mode parameters
|
||||
* previously established by setup() for this device
|
||||
*/
|
||||
int (*transfer)(struct spi_device *spi,
|
||||
struct spi_message *mesg);
|
||||
|
||||
/* called on release() to free memory provided by spi_master */
|
||||
void (*cleanup)(const struct spi_device *spi);
|
||||
};
|
||||
|
||||
static inline void *spi_master_get_devdata(struct spi_master *master)
|
||||
{
|
||||
return class_get_devdata(&master->cdev);
|
||||
}
|
||||
|
||||
static inline void spi_master_set_devdata(struct spi_master *master, void *data)
|
||||
{
|
||||
class_set_devdata(&master->cdev, data);
|
||||
}
|
||||
|
||||
static inline struct spi_master *spi_master_get(struct spi_master *master)
|
||||
{
|
||||
if (!master || !class_device_get(&master->cdev))
|
||||
return NULL;
|
||||
return master;
|
||||
}
|
||||
|
||||
static inline void spi_master_put(struct spi_master *master)
|
||||
{
|
||||
if (master)
|
||||
class_device_put(&master->cdev);
|
||||
}
|
||||
|
||||
|
||||
/* the spi driver core manages memory for the spi_master classdev */
|
||||
extern struct spi_master *
|
||||
spi_alloc_master(struct device *host, unsigned size);
|
||||
|
||||
extern int spi_register_master(struct spi_master *master);
|
||||
extern void spi_unregister_master(struct spi_master *master);
|
||||
|
||||
extern struct spi_master *spi_busnum_to_master(u16 busnum);
|
||||
|
||||
/*---------------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* I/O INTERFACE between SPI controller and protocol drivers
|
||||
*
|
||||
* Protocol drivers use a queue of spi_messages, each transferring data
|
||||
* between the controller and memory buffers.
|
||||
*
|
||||
* The spi_messages themselves consist of a series of read+write transfer
|
||||
* segments. Those segments always read the same number of bits as they
|
||||
* write; but one or the other is easily ignored by passing a null buffer
|
||||
* pointer. (This is unlike most types of I/O API, because SPI hardware
|
||||
* is full duplex.)
|
||||
*
|
||||
* NOTE: Allocation of spi_transfer and spi_message memory is entirely
|
||||
* up to the protocol driver, which guarantees the integrity of both (as
|
||||
* well as the data buffers) for as long as the message is queued.
|
||||
*/
|
||||
|
||||
/**
|
||||
* struct spi_transfer - a read/write buffer pair
|
||||
* @tx_buf: data to be written (dma-safe memory), or NULL
|
||||
* @rx_buf: data to be read (dma-safe memory), or NULL
|
||||
* @tx_dma: DMA address of tx_buf, if spi_message.is_dma_mapped
|
||||
* @rx_dma: DMA address of rx_buf, if spi_message.is_dma_mapped
|
||||
* @len: size of rx and tx buffers (in bytes)
|
||||
* @cs_change: affects chipselect after this transfer completes
|
||||
* @delay_usecs: microseconds to delay after this transfer before
|
||||
* (optionally) changing the chipselect status, then starting
|
||||
* the next transfer or completing this spi_message.
|
||||
* @transfer_list: transfers are sequenced through spi_message.transfers
|
||||
*
|
||||
* SPI transfers always write the same number of bytes as they read.
|
||||
* Protocol drivers should always provide rx_buf and/or tx_buf.
|
||||
* In some cases, they may also want to provide DMA addresses for
|
||||
* the data being transferred; that may reduce overhead, when the
|
||||
* underlying driver uses dma.
|
||||
*
|
||||
* If the transmit buffer is null, undefined data will be shifted out
|
||||
* while filling rx_buf. If the receive buffer is null, the data
|
||||
* shifted in will be discarded. Only "len" bytes shift out (or in).
|
||||
* It's an error to try to shift out a partial word. (For example, by
|
||||
* shifting out three bytes with word size of sixteen or twenty bits;
|
||||
* the former uses two bytes per word, the latter uses four bytes.)
|
||||
*
|
||||
* All SPI transfers start with the relevant chipselect active. Normally
|
||||
* it stays selected until after the last transfer in a message. Drivers
|
||||
* can affect the chipselect signal using cs_change:
|
||||
*
|
||||
* (i) If the transfer isn't the last one in the message, this flag is
|
||||
* used to make the chipselect briefly go inactive in the middle of the
|
||||
* message. Toggling chipselect in this way may be needed to terminate
|
||||
* a chip command, letting a single spi_message perform all of group of
|
||||
* chip transactions together.
|
||||
*
|
||||
* (ii) When the transfer is the last one in the message, the chip may
|
||||
* stay selected until the next transfer. This is purely a performance
|
||||
* hint; the controller driver may need to select a different device
|
||||
* for the next message.
|
||||
*
|
||||
* The code that submits an spi_message (and its spi_transfers)
|
||||
* to the lower layers is responsible for managing its memory.
|
||||
* Zero-initialize every field you don't set up explicitly, to
|
||||
* insulate against future API updates. After you submit a message
|
||||
* and its transfers, ignore them until its completion callback.
|
||||
*/
|
||||
struct spi_transfer {
|
||||
/* it's ok if tx_buf == rx_buf (right?)
|
||||
* for MicroWire, one buffer must be null
|
||||
* buffers must work with dma_*map_single() calls, unless
|
||||
* spi_message.is_dma_mapped reports a pre-existing mapping
|
||||
*/
|
||||
const void *tx_buf;
|
||||
void *rx_buf;
|
||||
unsigned len;
|
||||
|
||||
dma_addr_t tx_dma;
|
||||
dma_addr_t rx_dma;
|
||||
|
||||
unsigned cs_change:1;
|
||||
u16 delay_usecs;
|
||||
|
||||
struct list_head transfer_list;
|
||||
};
|
||||
|
||||
/**
|
||||
* struct spi_message - one multi-segment SPI transaction
|
||||
* @transfers: list of transfer segments in this transaction
|
||||
* @spi: SPI device to which the transaction is queued
|
||||
* @is_dma_mapped: if true, the caller provided both dma and cpu virtual
|
||||
* addresses for each transfer buffer
|
||||
* @complete: called to report transaction completions
|
||||
* @context: the argument to complete() when it's called
|
||||
* @actual_length: the total number of bytes that were transferred in all
|
||||
* successful segments
|
||||
* @status: zero for success, else negative errno
|
||||
* @queue: for use by whichever driver currently owns the message
|
||||
* @state: for use by whichever driver currently owns the message
|
||||
*
|
||||
* An spi_message is used to execute an atomic sequence of data transfers,
|
||||
* each represented by a struct spi_transfer. The sequence is "atomic"
|
||||
* in the sense that no other spi_message may use that SPI bus until that
|
||||
* sequence completes. On some systems, many such sequences can execute as
|
||||
* as single programmed DMA transfer. On all systems, these messages are
|
||||
* queued, and might complete after transactions to other devices. Messages
|
||||
* sent to a given spi_device are alway executed in FIFO order.
|
||||
*
|
||||
* The code that submits an spi_message (and its spi_transfers)
|
||||
* to the lower layers is responsible for managing its memory.
|
||||
* Zero-initialize every field you don't set up explicitly, to
|
||||
* insulate against future API updates. After you submit a message
|
||||
* and its transfers, ignore them until its completion callback.
|
||||
*/
|
||||
struct spi_message {
|
||||
struct list_head transfers;
|
||||
|
||||
struct spi_device *spi;
|
||||
|
||||
unsigned is_dma_mapped:1;
|
||||
|
||||
/* REVISIT: we might want a flag affecting the behavior of the
|
||||
* last transfer ... allowing things like "read 16 bit length L"
|
||||
* immediately followed by "read L bytes". Basically imposing
|
||||
* a specific message scheduling algorithm.
|
||||
*
|
||||
* Some controller drivers (message-at-a-time queue processing)
|
||||
* could provide that as their default scheduling algorithm. But
|
||||
* others (with multi-message pipelines) could need a flag to
|
||||
* tell them about such special cases.
|
||||
*/
|
||||
|
||||
/* completion is reported through a callback */
|
||||
void (*complete)(void *context);
|
||||
void *context;
|
||||
unsigned actual_length;
|
||||
int status;
|
||||
|
||||
/* for optional use by whatever driver currently owns the
|
||||
* spi_message ... between calls to spi_async and then later
|
||||
* complete(), that's the spi_master controller driver.
|
||||
*/
|
||||
struct list_head queue;
|
||||
void *state;
|
||||
};
|
||||
|
||||
static inline void spi_message_init(struct spi_message *m)
|
||||
{
|
||||
memset(m, 0, sizeof *m);
|
||||
INIT_LIST_HEAD(&m->transfers);
|
||||
}
|
||||
|
||||
static inline void
|
||||
spi_message_add_tail(struct spi_transfer *t, struct spi_message *m)
|
||||
{
|
||||
list_add_tail(&t->transfer_list, &m->transfers);
|
||||
}
|
||||
|
||||
static inline void
|
||||
spi_transfer_del(struct spi_transfer *t)
|
||||
{
|
||||
list_del(&t->transfer_list);
|
||||
}
|
||||
|
||||
/* It's fine to embed message and transaction structures in other data
|
||||
* structures so long as you don't free them while they're in use.
|
||||
*/
|
||||
|
||||
static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
|
||||
{
|
||||
struct spi_message *m;
|
||||
|
||||
m = kzalloc(sizeof(struct spi_message)
|
||||
+ ntrans * sizeof(struct spi_transfer),
|
||||
flags);
|
||||
if (m) {
|
||||
int i;
|
||||
struct spi_transfer *t = (struct spi_transfer *)(m + 1);
|
||||
|
||||
INIT_LIST_HEAD(&m->transfers);
|
||||
for (i = 0; i < ntrans; i++, t++)
|
||||
spi_message_add_tail(t, m);
|
||||
}
|
||||
return m;
|
||||
}
|
||||
|
||||
static inline void spi_message_free(struct spi_message *m)
|
||||
{
|
||||
kfree(m);
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_setup -- setup SPI mode and clock rate
|
||||
* @spi: the device whose settings are being modified
|
||||
*
|
||||
* SPI protocol drivers may need to update the transfer mode if the
|
||||
* device doesn't work with the mode 0 default. They may likewise need
|
||||
* to update clock rates or word sizes from initial values. This function
|
||||
* changes those settings, and must be called from a context that can sleep.
|
||||
* The changes take effect the next time the device is selected and data
|
||||
* is transferred to or from it.
|
||||
*/
|
||||
static inline int
|
||||
spi_setup(struct spi_device *spi)
|
||||
{
|
||||
return spi->master->setup(spi);
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* spi_async -- asynchronous SPI transfer
|
||||
* @spi: device with which data will be exchanged
|
||||
* @message: describes the data transfers, including completion callback
|
||||
*
|
||||
* This call may be used in_irq and other contexts which can't sleep,
|
||||
* as well as from task contexts which can sleep.
|
||||
*
|
||||
* The completion callback is invoked in a context which can't sleep.
|
||||
* Before that invocation, the value of message->status is undefined.
|
||||
* When the callback is issued, message->status holds either zero (to
|
||||
* indicate complete success) or a negative error code. After that
|
||||
* callback returns, the driver which issued the transfer request may
|
||||
* deallocate the associated memory; it's no longer in use by any SPI
|
||||
* core or controller driver code.
|
||||
*
|
||||
* Note that although all messages to a spi_device are handled in
|
||||
* FIFO order, messages may go to different devices in other orders.
|
||||
* Some device might be higher priority, or have various "hard" access
|
||||
* time requirements, for example.
|
||||
*
|
||||
* On detection of any fault during the transfer, processing of
|
||||
* the entire message is aborted, and the device is deselected.
|
||||
* Until returning from the associated message completion callback,
|
||||
* no other spi_message queued to that device will be processed.
|
||||
* (This rule applies equally to all the synchronous transfer calls,
|
||||
* which are wrappers around this core asynchronous primitive.)
|
||||
*/
|
||||
static inline int
|
||||
spi_async(struct spi_device *spi, struct spi_message *message)
|
||||
{
|
||||
message->spi = spi;
|
||||
return spi->master->transfer(spi, message);
|
||||
}
|
||||
|
||||
/*---------------------------------------------------------------------------*/
|
||||
|
||||
/* All these synchronous SPI transfer routines are utilities layered
|
||||
* over the core async transfer primitive. Here, "synchronous" means
|
||||
* they will sleep uninterruptibly until the async transfer completes.
|
||||
*/
|
||||
|
||||
extern int spi_sync(struct spi_device *spi, struct spi_message *message);
|
||||
|
||||
/**
|
||||
* spi_write - SPI synchronous write
|
||||
* @spi: device to which data will be written
|
||||
* @buf: data buffer
|
||||
* @len: data buffer size
|
||||
*
|
||||
* This writes the buffer and returns zero or a negative error code.
|
||||
* Callable only from contexts that can sleep.
|
||||
*/
|
||||
static inline int
|
||||
spi_write(struct spi_device *spi, const u8 *buf, size_t len)
|
||||
{
|
||||
struct spi_transfer t = {
|
||||
.tx_buf = buf,
|
||||
.len = len,
|
||||
};
|
||||
struct spi_message m;
|
||||
|
||||
spi_message_init(&m);
|
||||
spi_message_add_tail(&t, &m);
|
||||
return spi_sync(spi, &m);
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_read - SPI synchronous read
|
||||
* @spi: device from which data will be read
|
||||
* @buf: data buffer
|
||||
* @len: data buffer size
|
||||
*
|
||||
* This writes the buffer and returns zero or a negative error code.
|
||||
* Callable only from contexts that can sleep.
|
||||
*/
|
||||
static inline int
|
||||
spi_read(struct spi_device *spi, u8 *buf, size_t len)
|
||||
{
|
||||
struct spi_transfer t = {
|
||||
.rx_buf = buf,
|
||||
.len = len,
|
||||
};
|
||||
struct spi_message m;
|
||||
|
||||
spi_message_init(&m);
|
||||
spi_message_add_tail(&t, &m);
|
||||
return spi_sync(spi, &m);
|
||||
}
|
||||
|
||||
/* this copies txbuf and rxbuf data; for small transfers only! */
|
||||
extern int spi_write_then_read(struct spi_device *spi,
|
||||
const u8 *txbuf, unsigned n_tx,
|
||||
u8 *rxbuf, unsigned n_rx);
|
||||
|
||||
/**
|
||||
* spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
|
||||
* @spi: device with which data will be exchanged
|
||||
* @cmd: command to be written before data is read back
|
||||
*
|
||||
* This returns the (unsigned) eight bit number returned by the
|
||||
* device, or else a negative error code. Callable only from
|
||||
* contexts that can sleep.
|
||||
*/
|
||||
static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)
|
||||
{
|
||||
ssize_t status;
|
||||
u8 result;
|
||||
|
||||
status = spi_write_then_read(spi, &cmd, 1, &result, 1);
|
||||
|
||||
/* return negative errno or unsigned value */
|
||||
return (status < 0) ? status : result;
|
||||
}
|
||||
|
||||
/**
|
||||
* spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
|
||||
* @spi: device with which data will be exchanged
|
||||
* @cmd: command to be written before data is read back
|
||||
*
|
||||
* This returns the (unsigned) sixteen bit number returned by the
|
||||
* device, or else a negative error code. Callable only from
|
||||
* contexts that can sleep.
|
||||
*
|
||||
* The number is returned in wire-order, which is at least sometimes
|
||||
* big-endian.
|
||||
*/
|
||||
static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
|
||||
{
|
||||
ssize_t status;
|
||||
u16 result;
|
||||
|
||||
status = spi_write_then_read(spi, &cmd, 1, (u8 *) &result, 2);
|
||||
|
||||
/* return negative errno or unsigned value */
|
||||
return (status < 0) ? status : result;
|
||||
}
|
||||
|
||||
/*---------------------------------------------------------------------------*/
|
||||
|
||||
/*
|
||||
* INTERFACE between board init code and SPI infrastructure.
|
||||
*
|
||||
* No SPI driver ever sees these SPI device table segments, but
|
||||
* it's how the SPI core (or adapters that get hotplugged) grows
|
||||
* the driver model tree.
|
||||
*
|
||||
* As a rule, SPI devices can't be probed. Instead, board init code
|
||||
* provides a table listing the devices which are present, with enough
|
||||
* information to bind and set up the device's driver. There's basic
|
||||
* support for nonstatic configurations too; enough to handle adding
|
||||
* parport adapters, or microcontrollers acting as USB-to-SPI bridges.
|
||||
*/
|
||||
|
||||
/* board-specific information about each SPI device */
|
||||
struct spi_board_info {
|
||||
/* the device name and module name are coupled, like platform_bus;
|
||||
* "modalias" is normally the driver name.
|
||||
*
|
||||
* platform_data goes to spi_device.dev.platform_data,
|
||||
* controller_data goes to spi_device.controller_data,
|
||||
* irq is copied too
|
||||
*/
|
||||
char modalias[KOBJ_NAME_LEN];
|
||||
const void *platform_data;
|
||||
void *controller_data;
|
||||
int irq;
|
||||
|
||||
/* slower signaling on noisy or low voltage boards */
|
||||
u32 max_speed_hz;
|
||||
|
||||
|
||||
/* bus_num is board specific and matches the bus_num of some
|
||||
* spi_master that will probably be registered later.
|
||||
*
|
||||
* chip_select reflects how this chip is wired to that master;
|
||||
* it's less than num_chipselect.
|
||||
*/
|
||||
u16 bus_num;
|
||||
u16 chip_select;
|
||||
|
||||
/* ... may need additional spi_device chip config data here.
|
||||
* avoid stuff protocol drivers can set; but include stuff
|
||||
* needed to behave without being bound to a driver:
|
||||
* - chipselect polarity
|
||||
* - quirks like clock rate mattering when not selected
|
||||
*/
|
||||
};
|
||||
|
||||
#ifdef CONFIG_SPI
|
||||
extern int
|
||||
spi_register_board_info(struct spi_board_info const *info, unsigned n);
|
||||
#else
|
||||
/* board init code may ignore whether SPI is configured or not */
|
||||
static inline int
|
||||
spi_register_board_info(struct spi_board_info const *info, unsigned n)
|
||||
{ return 0; }
|
||||
#endif
|
||||
|
||||
|
||||
/* If you're hotplugging an adapter with devices (parport, usb, etc)
|
||||
* use spi_new_device() to describe each device. You can also call
|
||||
* spi_unregister_device() to start making that device vanish, but
|
||||
* normally that would be handled by spi_unregister_master().
|
||||
*/
|
||||
extern struct spi_device *
|
||||
spi_new_device(struct spi_master *, struct spi_board_info *);
|
||||
|
||||
static inline void
|
||||
spi_unregister_device(struct spi_device *spi)
|
||||
{
|
||||
if (spi)
|
||||
device_unregister(&spi->dev);
|
||||
}
|
||||
|
||||
#endif /* __LINUX_SPI_H */
|
||||
135
include/linux/spi/spi_bitbang.h
Normal file
135
include/linux/spi/spi_bitbang.h
Normal file
|
|
@ -0,0 +1,135 @@
|
|||
#ifndef __SPI_BITBANG_H
|
||||
#define __SPI_BITBANG_H
|
||||
|
||||
/*
|
||||
* Mix this utility code with some glue code to get one of several types of
|
||||
* simple SPI master driver. Two do polled word-at-a-time I/O:
|
||||
*
|
||||
* - GPIO/parport bitbangers. Provide chipselect() and txrx_word[](),
|
||||
* expanding the per-word routines from the inline templates below.
|
||||
*
|
||||
* - Drivers for controllers resembling bare shift registers. Provide
|
||||
* chipselect() and txrx_word[](), with custom setup()/cleanup() methods
|
||||
* that use your controller's clock and chipselect registers.
|
||||
*
|
||||
* Some hardware works well with requests at spi_transfer scope:
|
||||
*
|
||||
* - Drivers leveraging smarter hardware, with fifos or DMA; or for half
|
||||
* duplex (MicroWire) controllers. Provide chipslect() and txrx_bufs(),
|
||||
* and custom setup()/cleanup() methods.
|
||||
*/
|
||||
struct spi_bitbang {
|
||||
struct workqueue_struct *workqueue;
|
||||
struct work_struct work;
|
||||
|
||||
spinlock_t lock;
|
||||
struct list_head queue;
|
||||
u8 busy;
|
||||
u8 shutdown;
|
||||
u8 use_dma;
|
||||
|
||||
struct spi_master *master;
|
||||
|
||||
void (*chipselect)(struct spi_device *spi, int is_on);
|
||||
#define BITBANG_CS_ACTIVE 1 /* normally nCS, active low */
|
||||
#define BITBANG_CS_INACTIVE 0
|
||||
|
||||
/* txrx_bufs() may handle dma mapping for transfers that don't
|
||||
* already have one (transfer.{tx,rx}_dma is zero), or use PIO
|
||||
*/
|
||||
int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
|
||||
|
||||
/* txrx_word[SPI_MODE_*]() just looks like a shift register */
|
||||
u32 (*txrx_word[4])(struct spi_device *spi,
|
||||
unsigned nsecs,
|
||||
u32 word, u8 bits);
|
||||
};
|
||||
|
||||
/* you can call these default bitbang->master methods from your custom
|
||||
* methods, if you like.
|
||||
*/
|
||||
extern int spi_bitbang_setup(struct spi_device *spi);
|
||||
extern void spi_bitbang_cleanup(const struct spi_device *spi);
|
||||
extern int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m);
|
||||
|
||||
/* start or stop queue processing */
|
||||
extern int spi_bitbang_start(struct spi_bitbang *spi);
|
||||
extern int spi_bitbang_stop(struct spi_bitbang *spi);
|
||||
|
||||
#endif /* __SPI_BITBANG_H */
|
||||
|
||||
/*-------------------------------------------------------------------------*/
|
||||
|
||||
#ifdef EXPAND_BITBANG_TXRX
|
||||
|
||||
/*
|
||||
* The code that knows what GPIO pins do what should have declared four
|
||||
* functions, ideally as inlines, before #defining EXPAND_BITBANG_TXRX
|
||||
* and including this header:
|
||||
*
|
||||
* void setsck(struct spi_device *, int is_on);
|
||||
* void setmosi(struct spi_device *, int is_on);
|
||||
* int getmiso(struct spi_device *);
|
||||
* void spidelay(unsigned);
|
||||
*
|
||||
* A non-inlined routine would call bitbang_txrx_*() routines. The
|
||||
* main loop could easily compile down to a handful of instructions,
|
||||
* especially if the delay is a NOP (to run at peak speed).
|
||||
*
|
||||
* Since this is software, the timings may not be exactly what your board's
|
||||
* chips need ... there may be several reasons you'd need to tweak timings
|
||||
* in these routines, not just make to make it faster or slower to match a
|
||||
* particular CPU clock rate.
|
||||
*/
|
||||
|
||||
static inline u32
|
||||
bitbang_txrx_be_cpha0(struct spi_device *spi,
|
||||
unsigned nsecs, unsigned cpol,
|
||||
u32 word, u8 bits)
|
||||
{
|
||||
/* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */
|
||||
|
||||
/* clock starts at inactive polarity */
|
||||
for (word <<= (32 - bits); likely(bits); bits--) {
|
||||
|
||||
/* setup MSB (to slave) on trailing edge */
|
||||
setmosi(spi, word & (1 << 31));
|
||||
spidelay(nsecs); /* T(setup) */
|
||||
|
||||
setsck(spi, !cpol);
|
||||
spidelay(nsecs);
|
||||
|
||||
/* sample MSB (from slave) on leading edge */
|
||||
word <<= 1;
|
||||
word |= getmiso(spi);
|
||||
setsck(spi, cpol);
|
||||
}
|
||||
return word;
|
||||
}
|
||||
|
||||
static inline u32
|
||||
bitbang_txrx_be_cpha1(struct spi_device *spi,
|
||||
unsigned nsecs, unsigned cpol,
|
||||
u32 word, u8 bits)
|
||||
{
|
||||
/* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */
|
||||
|
||||
/* clock starts at inactive polarity */
|
||||
for (word <<= (32 - bits); likely(bits); bits--) {
|
||||
|
||||
/* setup MSB (to slave) on leading edge */
|
||||
setsck(spi, !cpol);
|
||||
setmosi(spi, word & (1 << 31));
|
||||
spidelay(nsecs); /* T(setup) */
|
||||
|
||||
setsck(spi, cpol);
|
||||
spidelay(nsecs);
|
||||
|
||||
/* sample MSB (from slave) on trailing edge */
|
||||
word <<= 1;
|
||||
word |= getmiso(spi);
|
||||
}
|
||||
return word;
|
||||
}
|
||||
|
||||
#endif /* EXPAND_BITBANG_TXRX */
|
||||
Loading…
Reference in a new issue