diff options
Diffstat (limited to 'drivers/hwmon/tmp102.c')
| -rw-r--r-- | drivers/hwmon/tmp102.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c new file mode 100644 index 000000000..dfc40c740 --- /dev/null +++ b/drivers/hwmon/tmp102.c @@ -0,0 +1,341 @@ +/* Texas Instruments TMP102 SMBus temperature sensor driver + * + * Copyright (C) 2010 Steven King <sfking@fdwdc.com> + * + * 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. + */ + +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/device.h> +#include <linux/jiffies.h> +#include <linux/regmap.h> +#include <linux/of.h> + +#define DRIVER_NAME "tmp102" + +#define TMP102_TEMP_REG 0x00 +#define TMP102_CONF_REG 0x01 +/* note: these bit definitions are byte swapped */ +#define TMP102_CONF_SD 0x0100 +#define TMP102_CONF_TM 0x0200 +#define TMP102_CONF_POL 0x0400 +#define TMP102_CONF_F0 0x0800 +#define TMP102_CONF_F1 0x1000 +#define TMP102_CONF_R0 0x2000 +#define TMP102_CONF_R1 0x4000 +#define TMP102_CONF_OS 0x8000 +#define TMP102_CONF_EM 0x0010 +#define TMP102_CONF_AL 0x0020 +#define TMP102_CONF_CR0 0x0040 +#define TMP102_CONF_CR1 0x0080 +#define TMP102_TLOW_REG 0x02 +#define TMP102_THIGH_REG 0x03 + +#define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ + TMP102_CONF_POL | TMP102_CONF_F0 | \ + TMP102_CONF_F1 | TMP102_CONF_OS | \ + TMP102_CONF_EM | TMP102_CONF_AL | \ + TMP102_CONF_CR0 | TMP102_CONF_CR1) + +#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ + TMP102_CONF_CR0) +#define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ + TMP102_CONF_CR1) + +#define CONVERSION_TIME_MS 35 /* in milli-seconds */ + +struct tmp102 { + struct regmap *regmap; + u16 config_orig; + unsigned long ready_time; +}; + +/* convert left adjusted 13-bit TMP102 register value to milliCelsius */ +static inline int tmp102_reg_to_mC(s16 val) +{ + return ((val & ~0x01) * 1000) / 128; +} + +/* convert milliCelsius to left adjusted 13-bit TMP102 register value */ +static inline u16 tmp102_mC_to_reg(int val) +{ + return (val * 128) / 1000; +} + +static int tmp102_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *temp) +{ + struct tmp102 *tmp102 = dev_get_drvdata(dev); + unsigned int regval; + int err, reg; + + switch (attr) { + case hwmon_temp_input: + /* Is it too early to return a conversion ? */ + if (time_before(jiffies, tmp102->ready_time)) { + dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); + return -EAGAIN; + } + reg = TMP102_TEMP_REG; + break; + case hwmon_temp_max_hyst: + reg = TMP102_TLOW_REG; + break; + case hwmon_temp_max: + reg = TMP102_THIGH_REG; + break; + default: + return -EOPNOTSUPP; + } + + err = regmap_read(tmp102->regmap, reg, ®val); + if (err < 0) + return err; + *temp = tmp102_reg_to_mC(regval); + + return 0; +} + +static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long temp) +{ + struct tmp102 *tmp102 = dev_get_drvdata(dev); + int reg; + + switch (attr) { + case hwmon_temp_max_hyst: + reg = TMP102_TLOW_REG; + break; + case hwmon_temp_max: + reg = TMP102_THIGH_REG; + break; + default: + return -EOPNOTSUPP; + } + + temp = clamp_val(temp, -256000, 255000); + return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp)); +} + +static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type != hwmon_temp) + return 0; + + switch (attr) { + case hwmon_temp_input: + return S_IRUGO; + case hwmon_temp_max_hyst: + case hwmon_temp_max: + return S_IRUGO | S_IWUSR; + default: + return 0; + } +} + +static u32 tmp102_chip_config[] = { + HWMON_C_REGISTER_TZ, + 0 +}; + +static const struct hwmon_channel_info tmp102_chip = { + .type = hwmon_chip, + .config = tmp102_chip_config, +}; + +static u32 tmp102_temp_config[] = { + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, + 0 +}; + +static const struct hwmon_channel_info tmp102_temp = { + .type = hwmon_temp, + .config = tmp102_temp_config, +}; + +static const struct hwmon_channel_info *tmp102_info[] = { + &tmp102_chip, + &tmp102_temp, + NULL +}; + +static const struct hwmon_ops tmp102_hwmon_ops = { + .is_visible = tmp102_is_visible, + .read = tmp102_read, + .write = tmp102_write, +}; + +static const struct hwmon_chip_info tmp102_chip_info = { + .ops = &tmp102_hwmon_ops, + .info = tmp102_info, +}; + +static void tmp102_restore_config(void *data) +{ + struct tmp102 *tmp102 = data; + + regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); +} + +static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) +{ + return reg != TMP102_TEMP_REG; +} + +static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) +{ + return reg == TMP102_TEMP_REG; +} + +static const struct regmap_config tmp102_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .max_register = TMP102_THIGH_REG, + .writeable_reg = tmp102_is_writeable_reg, + .volatile_reg = tmp102_is_volatile_reg, + .val_format_endian = REGMAP_ENDIAN_BIG, + .cache_type = REGCACHE_RBTREE, + .use_single_rw = true, +}; + +static int tmp102_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct tmp102 *tmp102; + unsigned int regval; + int err; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WORD_DATA)) { + dev_err(dev, + "adapter doesn't support SMBus word transactions\n"); + return -ENODEV; + } + + tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); + if (!tmp102) + return -ENOMEM; + + i2c_set_clientdata(client, tmp102); + + tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); + if (IS_ERR(tmp102->regmap)) + return PTR_ERR(tmp102->regmap); + + err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); + if (err < 0) { + dev_err(dev, "error reading config register\n"); + return err; + } + + if ((regval & ~TMP102_CONFREG_MASK) != + (TMP102_CONF_R0 | TMP102_CONF_R1)) { + dev_err(dev, "unexpected config register value\n"); + return -ENODEV; + } + + tmp102->config_orig = regval; + + err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); + if (err) + return err; + + regval &= ~TMP102_CONFIG_CLEAR; + regval |= TMP102_CONFIG_SET; + + err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); + if (err < 0) { + dev_err(dev, "error writing config register\n"); + return err; + } + + /* + * Mark that we are not ready with data until the first + * conversion is complete + */ + tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, + tmp102, + &tmp102_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) { + dev_dbg(dev, "unable to register hwmon device\n"); + return PTR_ERR(hwmon_dev); + } + dev_info(dev, "initialized\n"); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int tmp102_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tmp102 *tmp102 = i2c_get_clientdata(client); + + return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, + TMP102_CONF_SD, TMP102_CONF_SD); +} + +static int tmp102_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tmp102 *tmp102 = i2c_get_clientdata(client); + int err; + + err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, + TMP102_CONF_SD, 0); + + tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); + + return err; +} +#endif /* CONFIG_PM */ + +static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); + +static const struct i2c_device_id tmp102_id[] = { + { "tmp102", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tmp102_id); + +static const struct of_device_id tmp102_of_match[] = { + { .compatible = "ti,tmp102" }, + { }, +}; +MODULE_DEVICE_TABLE(of, tmp102_of_match); + +static struct i2c_driver tmp102_driver = { + .driver.name = DRIVER_NAME, + .driver.of_match_table = of_match_ptr(tmp102_of_match), + .driver.pm = &tmp102_dev_pm_ops, + .probe = tmp102_probe, + .id_table = tmp102_id, +}; + +module_i2c_driver(tmp102_driver); + +MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); +MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); +MODULE_LICENSE("GPL"); |