/* 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/thermal.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_temp(void *dev, int *temp)
{
struct tmp102 *tmp102 = dev_get_drvdata(dev);
unsigned int reg;
int ret;
if (time_before(jiffies, tmp102->ready_time)) {
dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
return -EAGAIN;
}
ret = regmap_read(tmp102->regmap, TMP102_TEMP_REG, ®);
if (ret < 0)
return ret;
*temp = tmp102_reg_to_mC(reg);
return 0;
}
static ssize_t tmp102_show_temp(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
struct tmp102 *tmp102 = dev_get_drvdata(dev);
int regaddr = sda->index;
unsigned int reg;
int err;
if (regaddr == TMP102_TEMP_REG &&
time_before(jiffies, tmp102->ready_time))
return -EAGAIN;
err = regmap_read(tmp102->regmap, regaddr, ®);
if (err < 0)
return err;
return sprintf(buf, "%d\n", tmp102_reg_to_mC(reg));
}
static ssize_t tmp102_set_temp(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
struct tmp102 *tmp102 = dev_get_drvdata(dev);
int reg = sda->index;
long val;
int err;
if (kstrtol(buf, 10, &val) < 0)
return -EINVAL;
val = clamp_val(val, -256000, 255000);
err = regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(val));
return err ? : count;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL,
TMP102_TEMP_REG);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
tmp102_set_temp, TMP102_TLOW_REG);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
tmp102_set_temp, TMP102_THIGH_REG);
static struct attribute *tmp102_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(tmp102);
static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = {
.get_temp = tmp102_read_temp,
};
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;
}
tmp102->ready_time = jiffies;
if (tmp102->config_orig & TMP102_CONF_SD) {
/*
* Mark that we are not ready with data until the first
* conversion is complete
*/
tmp102->ready_time += msecs_to_jiffies(CONVERSION_TIME_MS);
}
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
tmp102,
tmp102_groups);
if (IS_ERR(hwmon_dev)) {
dev_dbg(dev, "unable to register hwmon device\n");
return PTR_ERR(hwmon_dev);
}
devm_thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev,
&tmp102_of_thermal_ops);
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 struct i2c_driver tmp102_driver = {
.driver.name = DRIVER_NAME,
.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");
