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linux/drivers/hwmon/tmp102.c
Eduardo Valentin 6a027523f3 hwmon: tmp102: expose to thermal fw via DT nodes 
This patch adds to tmp102 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the tmp102 DT node. Otherwise, the driver behavior
will be the same.

Note: This patch has also been reviewed by Jean D. He has
requested to perform a wider inspection of possible
users of thermal and hwmon interaction API. On the other
hand, the change on this patch is acceptable on first
step of overall code change.

Cc: Jean Delvare <khali@linux-fr.org>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
2013-12-04 09:34:25 -04:00

314 lines
8.5 KiB
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/* 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>
#include <linux/jiffies.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
struct tmp102 {
struct device *hwmon_dev;
struct thermal_zone_device *tz;
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 int tmp102_read_temp(void *dev, long *temp)
{
struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
*temp = tmp102->temp[0];
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 = 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 (kstrtol(buf, 10, &val) < 0)
return -EINVAL;
val = clamp_val(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 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 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL);
if (!tmp102)
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");
return status;
}
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;
}
tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
&client->dev,
tmp102_read_temp, NULL);
if (IS_ERR(tmp102->tz))
tmp102->tz = NULL;
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);
return status;
}
static int tmp102_remove(struct i2c_client *client)
{
struct tmp102 *tmp102 = i2c_get_clientdata(client);
thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
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);
}
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 = tmp102_remove,
.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");
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