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mfd: Add AUXADC support for WM8350

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The auxiliary ADC in the WM8350 is shared between several subdevices
so access to it needs to be arbitrated by the core driver.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
This commit is contained in:
Mark Brown 2008-11-08 01:10:21 +01:00 committed by Samuel Ortiz
parent 0c8a601678
commit 6748852634
3 changed files with 60 additions and 1 deletions
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51
drivers/mfd/wm8350-core.c
View file

@ -63,7 +63,6 @@
*/
static DEFINE_MUTEX(io_mutex);
static DEFINE_MUTEX(reg_lock_mutex);
static DEFINE_MUTEX(auxadc_mutex);
/* Perform a physical read from the device.
*/
@ -1082,6 +1081,55 @@ int wm8350_unmask_irq(struct wm8350 *wm8350, int irq)
}
EXPORT_SYMBOL_GPL(wm8350_unmask_irq);
int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale, int vref)
{
u16 reg, result = 0;
int tries = 5;
if (channel < WM8350_AUXADC_AUX1 || channel > WM8350_AUXADC_TEMP)
return -EINVAL;
if (channel >= WM8350_AUXADC_USB && channel <= WM8350_AUXADC_TEMP
&& (scale != 0 || vref != 0))
return -EINVAL;
mutex_lock(&wm8350->auxadc_mutex);
/* Turn on the ADC */
reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5, reg | WM8350_AUXADC_ENA);
if (scale || vref) {
reg = scale << 13;
reg |= vref << 12;
wm8350_reg_write(wm8350, WM8350_AUX1_READBACK + channel, reg);
}
reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
reg |= 1 << channel | WM8350_AUXADC_POLL;
wm8350_reg_write(wm8350, WM8350_DIGITISER_CONTROL_1, reg);
do {
schedule_timeout_interruptible(1);
reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
} while (tries-- && (reg & WM8350_AUXADC_POLL));
if (!tries)
dev_err(wm8350->dev, "adc chn %d read timeout\n", channel);
else
result = wm8350_reg_read(wm8350,
WM8350_AUX1_READBACK + channel);
/* Turn off the ADC */
reg = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
wm8350_reg_write(wm8350, WM8350_POWER_MGMT_5,
reg & ~WM8350_AUXADC_ENA);
mutex_unlock(&wm8350->auxadc_mutex);
return result & WM8350_AUXADC_DATA1_MASK;
}
EXPORT_SYMBOL_GPL(wm8350_read_auxadc);
/*
* Cache is always host endian.
*/
@ -1239,6 +1287,7 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
}
}
mutex_init(&wm8350->auxadc_mutex);
mutex_init(&wm8350->irq_mutex);
INIT_WORK(&wm8350->irq_work, wm8350_irq_worker);
if (irq) {

8
include/linux/mfd/wm8350/comparator.h
View file

@ -164,4 +164,12 @@
#define WM8350_AUXADC_BATT 6
#define WM8350_AUXADC_TEMP 7
struct wm8350;
/*
* AUX ADC Readback
*/
int wm8350_read_auxadc(struct wm8350 *wm8350, int channel, int scale,
int vref);
#endif

2
include/linux/mfd/wm8350/core.h
View file

@ -573,6 +573,8 @@ struct wm8350 {
void *src);
u16 *reg_cache;
struct mutex auxadc_mutex;
/* Interrupt handling */
struct work_struct irq_work;
struct mutex irq_mutex; /* IRQ table mutex */