From c8ac32e4711639c81e5f4d4cd78c8f21675a2bae Mon Sep 17 00:00:00 2001 From: Manuel Lauss Date: Wed, 7 Jan 2009 16:37:34 +0100 Subject: [PATCH] hwmon: (lm70) Add TI TMP121 support The Texas Instruments TMP121 is a SPI temperature sensor very similar to the LM70, with slightly higher resolution. This patch extends the LM70 driver to support the TMP121. The TMP123 differs in pin assign- ment. Signed-off-by: Manuel Lauss Signed-off-by: Jean Delvare --- Documentation/hwmon/lm70 | 8 +++- drivers/hwmon/Kconfig | 5 ++- drivers/hwmon/lm70.c | 84 +++++++++++++++++++++++++++++++++++----- 3 files changed, 84 insertions(+), 13 deletions(-) diff --git a/Documentation/hwmon/lm70 b/Documentation/hwmon/lm70 index b8d1a521e68..0d240291e3c 100644 --- a/Documentation/hwmon/lm70 +++ b/Documentation/hwmon/lm70 @@ -1,9 +1,11 @@ Kernel driver lm70 ================== -Supported chip: +Supported chips: * National Semiconductor LM70 Datasheet: http://www.national.com/pf/LM/LM70.html + * Texas Instruments TMP121/TMP123 + Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html Author: Kaiwan N Billimoria @@ -29,6 +31,10 @@ As a real (in-tree) example of this "SPI protocol driver" interfacing with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c and its associated documentation. +The TMP121/TMP123 are very similar; main differences are 4 wire SPI inter- +face (read only) and 13-bit temperature data (0.0625 degrees celsius reso- +lution). + Thanks to --------- Jean Delvare for mentoring the hwmon-side driver diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 3c34fb5e419..4b33bc82cc2 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -428,11 +428,12 @@ config SENSORS_LM63 will be called lm63. config SENSORS_LM70 - tristate "National Semiconductor LM70" + tristate "National Semiconductor LM70 / Texas Instruments TMP121" depends on SPI_MASTER && EXPERIMENTAL help If you say yes here you get support for the National Semiconductor - LM70 digital temperature sensor chip. + LM70 and Texas Instruments TMP121/TMP123 digital temperature + sensor chips. This driver can also be built as a module. If so, the module will be called lm70. diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c index 9f9741b1d2b..ae6204f3321 100644 --- a/drivers/hwmon/lm70.c +++ b/drivers/hwmon/lm70.c @@ -37,9 +37,13 @@ #define DRVNAME "lm70" +#define LM70_CHIP_LM70 0 /* original NS LM70 */ +#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */ + struct lm70 { struct device *hwmon_dev; struct mutex lock; + unsigned int chip; }; /* sysfs hook function */ @@ -47,7 +51,7 @@ static ssize_t lm70_sense_temp(struct device *dev, struct device_attribute *attr, char *buf) { struct spi_device *spi = to_spi_device(dev); - int status, val; + int status, val = 0; u8 rxbuf[2]; s16 raw=0; struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev); @@ -70,6 +74,7 @@ static ssize_t lm70_sense_temp(struct device *dev, rxbuf[0], rxbuf[1], raw); /* + * LM70: * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's * complement value. Only the MSB 11 bits (1 sign + 10 temperature * bits) are meaningful; the LSB 5 bits are to be discarded. @@ -79,8 +84,21 @@ static ssize_t lm70_sense_temp(struct device *dev, * by 0.25. Also multiply by 1000 to represent in millidegrees * Celsius. * So it's equivalent to multiplying by 0.25 * 1000 = 250. + * + * TMP121/TMP123: + * 13 bits of 2's complement data, discard LSB 3 bits, + * resolution 0.0625 degrees celsius. */ - val = ((int)raw/32) * 250; + switch (p_lm70->chip) { + case LM70_CHIP_LM70: + val = ((int)raw / 32) * 250; + break; + + case LM70_CHIP_TMP121: + val = ((int)raw / 8) * 625 / 10; + break; + } + status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */ out: mutex_unlock(&p_lm70->lock); @@ -92,22 +110,31 @@ static DEVICE_ATTR(temp1_input, S_IRUGO, lm70_sense_temp, NULL); static ssize_t lm70_show_name(struct device *dev, struct device_attribute *devattr, char *buf) { - return sprintf(buf, "lm70\n"); + struct lm70 *p_lm70 = dev_get_drvdata(dev); + int ret; + + switch (p_lm70->chip) { + case LM70_CHIP_LM70: + ret = sprintf(buf, "lm70\n"); + break; + case LM70_CHIP_TMP121: + ret = sprintf(buf, "tmp121\n"); + break; + default: + ret = -EINVAL; + } + return ret; } static DEVICE_ATTR(name, S_IRUGO, lm70_show_name, NULL); /*----------------------------------------------------------------------*/ -static int __devinit lm70_probe(struct spi_device *spi) +static int __devinit common_probe(struct spi_device *spi, int chip) { struct lm70 *p_lm70; int status; - /* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */ - if ((spi->mode & (SPI_CPOL|SPI_CPHA)) || !(spi->mode & SPI_3WIRE)) - return -EINVAL; - /* NOTE: we assume 8-bit words, and convert to 16 bits manually */ p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL); @@ -115,6 +142,7 @@ static int __devinit lm70_probe(struct spi_device *spi) return -ENOMEM; mutex_init(&p_lm70->lock); + p_lm70->chip = chip; /* sysfs hook */ p_lm70->hwmon_dev = hwmon_device_register(&spi->dev); @@ -142,6 +170,24 @@ out_dev_reg_failed: return status; } +static int __devinit lm70_probe(struct spi_device *spi) +{ + /* signaling is SPI_MODE_0 on a 3-wire link (shared SI/SO) */ + if ((spi->mode & (SPI_CPOL | SPI_CPHA)) || !(spi->mode & SPI_3WIRE)) + return -EINVAL; + + return common_probe(spi, LM70_CHIP_LM70); +} + +static int __devinit tmp121_probe(struct spi_device *spi) +{ + /* signaling is SPI_MODE_0 with only MISO connected */ + if (spi->mode & (SPI_CPOL | SPI_CPHA)) + return -EINVAL; + + return common_probe(spi, LM70_CHIP_TMP121); +} + static int __devexit lm70_remove(struct spi_device *spi) { struct lm70 *p_lm70 = dev_get_drvdata(&spi->dev); @@ -155,6 +201,15 @@ static int __devexit lm70_remove(struct spi_device *spi) return 0; } +static struct spi_driver tmp121_driver = { + .driver = { + .name = "tmp121", + .owner = THIS_MODULE, + }, + .probe = tmp121_probe, + .remove = __devexit_p(lm70_remove), +}; + static struct spi_driver lm70_driver = { .driver = { .name = "lm70", @@ -166,17 +221,26 @@ static struct spi_driver lm70_driver = { static int __init init_lm70(void) { - return spi_register_driver(&lm70_driver); + int ret = spi_register_driver(&lm70_driver); + if (ret) + return ret; + + ret = spi_register_driver(&tmp121_driver); + if (ret) + spi_unregister_driver(&lm70_driver); + + return ret; } static void __exit cleanup_lm70(void) { spi_unregister_driver(&lm70_driver); + spi_unregister_driver(&tmp121_driver); } module_init(init_lm70); module_exit(cleanup_lm70); MODULE_AUTHOR("Kaiwan N Billimoria"); -MODULE_DESCRIPTION("National Semiconductor LM70 Linux driver"); +MODULE_DESCRIPTION("NS LM70 / TI TMP121/TMP123 Linux driver"); MODULE_LICENSE("GPL");