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linux/drivers/hwmon/tmp102.c
Wolfram Sang fbae3fb154 i2c: Remove all i2c_set_clientdata(client, NULL) in drivers 
I2C drivers can use the clientdata-pointer to point to private data. As I2C
devices are not really unregistered, but merely detached from their driver, it
used to be the drivers obligation to clear this pointer during remove() or a
failed probe(). As a couple of drivers forgot to do this, it was agreed that it
was cleaner if the i2c-core does this clearance when appropriate, as there is
no guarantee for the lifetime of the clientdata-pointer after remove() anyhow.
This feature was added to the core with commit
e4a7b9b04d to fix the faulty drivers.

As there is no need anymore to clear the clientdata-pointer, remove all current
occurrences in the drivers to simplify the code and prevent confusion.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-06-03 11:33:58 +02:00

319 lines
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C
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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>
#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];
};
/* SMBus specifies low byte first, but the TMP102 returns high byte first,
* so we have to swab16 the values */
static inline int tmp102_read_reg(struct i2c_client *client, u8 reg)
{
int result = i2c_smbus_read_word_data(client, reg);
return result < 0 ? result : swab16(result);
}
static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
{
return i2c_smbus_write_word_data(client, reg, swab16(val));
}
/* 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 = tmp102_read_reg(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 = tmp102_write_reg(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 doesnt 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 = tmp102_read_reg(client, TMP102_CONF_REG);
if (status < 0) {
dev_err(&client->dev, "error reading config register\n");
goto fail_free;
}
tmp102->config_orig = status;
status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
if (status < 0) {
dev_err(&client->dev, "error writing config register\n");
goto fail_restore_config;
}
status = tmp102_read_reg(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:
tmp102_write_reg(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 = tmp102_read_reg(client, TMP102_CONF_REG);
if (config >= 0)
tmp102_write_reg(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 = tmp102_read_reg(client, TMP102_CONF_REG);
if (config < 0)
return config;
config |= TMP102_CONF_SD;
return tmp102_write_reg(client, TMP102_CONF_REG, config);
}
static int tmp102_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
int config;
config = tmp102_read_reg(client, TMP102_CONF_REG);
if (config < 0)
return config;
config &= ~TMP102_CONF_SD;
return tmp102_write_reg(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");
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