/* 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.
*
* 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., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
*/
#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>
#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
struct tmp102 {
struct device *hwmon_dev;
struct mutex lock;
u16 config_orig;
unsigned long last_update;
int temp[3];
};
/* 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 const u8 tmp102_reg[] = {
TMP102_TEMP_REG,
TMP102_TLOW_REG,
TMP102_THIGH_REG,
};
static struct tmp102 *tmp102_update_device(struct i2c_client *client)
{
struct tmp102 *tmp102 = i2c_get_clientdata(client);
mutex_lock(&tmp102->lock);
if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
int i;
for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
int status = i2c_smbus_read_word_swapped(client,
tmp102_reg[i]);
if (status > -1)
tmp102->temp[i] = tmp102_reg_to_mC(status);
}
tmp102->last_update = jiffies;
}
mutex_unlock(&tmp102->lock);
return tmp102;
}
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 = tmp102_update_device(to_i2c_client(dev));
return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
}
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 i2c_client *client = to_i2c_client(dev);
struct tmp102 *tmp102 = i2c_get_clientdata(client);
long val;
int status;
if (strict_strtol(buf, 10, &val) < 0)
return -EINVAL;
val = SENSORS_LIMIT(val, -256000, 255000);
mutex_lock(&tmp102->lock);
tmp102->temp[sda->index] = val;
status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
tmp102_mC_to_reg(val));
mutex_unlock(&tmp102->lock);
return status ? : count;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
tmp102_set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
tmp102_set_temp, 2);
static struct attribute *tmp102_attributes[] = {
&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
};
static const struct attribute_group tmp102_attr_group = {
.attrs = tmp102_attributes,
};
#define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
static int __devinit tmp102_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tmp102 *tmp102;
int status;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_err(&client->dev, "adapter doesn't support SMBus word "
"transactions\n");
return -ENODEV;
}
tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL);
if (!tmp102) {
dev_dbg(&client->dev, "kzalloc failed\n");
return -ENOMEM;
}
i2c_set_clientdata(client, tmp102);
status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (status < 0) {
dev_err(&client->dev, "error reading config register\n");
goto fail_free;
}
tmp102->config_orig = status;
status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
TMP102_CONFIG);
if (status < 0) {
dev_err(&client->dev, "error writing config register\n");
goto fail_restore_config;
}
status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (status < 0) {
dev_err(&client->dev, "error reading config register\n");
goto fail_restore_config;
}
status &= ~TMP102_CONFIG_RD_ONLY;
if (status != TMP102_CONFIG) {
dev_err(&client->dev, "config settings did not stick\n");
status = -ENODEV;
goto fail_restore_config;
}
tmp102->last_update = jiffies - HZ;
mutex_init(&tmp102->lock);
status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
if (status) {
dev_dbg(&client->dev, "could not create sysfs files\n");
goto fail_restore_config;
}
tmp102->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(tmp102->hwmon_dev)) {
dev_dbg(&client->dev, "unable to register hwmon device\n");
status = PTR_ERR(tmp102->hwmon_dev);
goto fail_remove_sysfs;
}
dev_info(&client->dev, "initialized\n");
return 0;
fail_remove_sysfs:
sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
fail_restore_config:
i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
tmp102->config_orig);
fail_free:
kfree(tmp102);
return status;
}
static int __devexit tmp102_remove(struct i2c_client *client)
{
struct tmp102 *tmp102 = i2c_get_clientdata(client);
hwmon_device_unregister(tmp102->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
/* Stop monitoring if device was stopped originally */
if (tmp102->config_orig & TMP102_CONF_SD) {
int config;
config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (config >= 0)
i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
config | TMP102_CONF_SD);
}
kfree(tmp102);
return 0;
}
#ifdef CONFIG_PM
static int tmp102_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
int config;
config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (config < 0)
return config;
config |= TMP102_CONF_SD;
return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
}
static int tmp102_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
int config;
config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (config < 0)
return config;
config &= ~TMP102_CONF_SD;
return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
}
static const struct dev_pm_ops tmp102_dev_pm_ops = {
.suspend = tmp102_suspend,
.resume = tmp102_resume,
};
#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
#else
#define TMP102_DEV_PM_OPS NULL
#endif /* CONFIG_PM */
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,
.remove = __devexit_p(tmp102_remove),
.id_table = tmp102_id,
};
static int __init tmp102_init(void)
{
return i2c_add_driver(&tmp102_driver);
}
module_init(tmp102_init);
static void __exit tmp102_exit(void)
{
i2c_del_driver(&tmp102_driver);
}
module_exit(tmp102_exit);
MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
MODULE_LICENSE("GPL");
