kernel-ark/drivers/hwmon/lm73.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

201 lines
4.9 KiB
C

/*
* LM73 Sensor driver
* Based on LM75
*
* Copyright (C) 2007, CenoSYS (www.cenosys.com).
* Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
*
* Guillaume Ligneul <guillaume.ligneul@gmail.com>
* Adrien Demarez <adrien.demarez@bolloretelecom.eu>
* Jeremy Laine <jeremy.laine@bolloretelecom.eu>
*
* This software program is licensed subject to the GNU General Public License
* (GPL).Version 2,June 1991, available at
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
0x4d, 0x4e, I2C_CLIENT_END };
/* LM73 registers */
#define LM73_REG_INPUT 0x00
#define LM73_REG_CONF 0x01
#define LM73_REG_MAX 0x02
#define LM73_REG_MIN 0x03
#define LM73_REG_CTRL 0x04
#define LM73_REG_ID 0x07
#define LM73_ID 0x9001 /* or 0x190 after a swab16() */
#define DRVNAME "lm73"
#define LM73_TEMP_MIN (-40)
#define LM73_TEMP_MAX 150
/*-----------------------------------------------------------------------*/
static ssize_t set_temp(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
long temp;
short value;
int status = strict_strtol(buf, 10, &temp);
if (status < 0)
return status;
/* Write value */
value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4),
(LM73_TEMP_MAX*4)) << 5;
i2c_smbus_write_word_data(client, attr->index, swab16(value));
return count;
}
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
/* use integer division instead of equivalent right shift to
guarantee arithmetic shift and preserve the sign */
int temp = ((s16) (swab16(i2c_smbus_read_word_data(client,
attr->index)))*250) / 32;
return sprintf(buf, "%d\n", temp);
}
/*-----------------------------------------------------------------------*/
/* sysfs attributes for hwmon */
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
show_temp, set_temp, LM73_REG_MAX);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
show_temp, set_temp, LM73_REG_MIN);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
show_temp, NULL, LM73_REG_INPUT);
static struct attribute *lm73_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
NULL
};
static const struct attribute_group lm73_group = {
.attrs = lm73_attributes,
};
/*-----------------------------------------------------------------------*/
/* device probe and removal */
static int
lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
struct device *hwmon_dev;
int status;
/* Register sysfs hooks */
status = sysfs_create_group(&client->dev.kobj, &lm73_group);
if (status)
return status;
hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(hwmon_dev)) {
status = PTR_ERR(hwmon_dev);
goto exit_remove;
}
i2c_set_clientdata(client, hwmon_dev);
dev_info(&client->dev, "%s: sensor '%s'\n",
dev_name(hwmon_dev), client->name);
return 0;
exit_remove:
sysfs_remove_group(&client->dev.kobj, &lm73_group);
return status;
}
static int lm73_remove(struct i2c_client *client)
{
struct device *hwmon_dev = i2c_get_clientdata(client);
hwmon_device_unregister(hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &lm73_group);
return 0;
}
static const struct i2c_device_id lm73_ids[] = {
{ "lm73", 0 },
{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, lm73_ids);
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm73_detect(struct i2c_client *new_client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = new_client->adapter;
u16 id;
u8 ctrl;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
/* Check device ID */
id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
if ((id != LM73_ID) || (ctrl & 0x10))
return -ENODEV;
strlcpy(info->type, "lm73", I2C_NAME_SIZE);
return 0;
}
static struct i2c_driver lm73_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "lm73",
},
.probe = lm73_probe,
.remove = lm73_remove,
.id_table = lm73_ids,
.detect = lm73_detect,
.address_list = normal_i2c,
};
/* module glue */
static int __init sensors_lm73_init(void)
{
return i2c_add_driver(&lm73_driver);
}
static void __exit sensors_lm73_exit(void)
{
i2c_del_driver(&lm73_driver);
}
MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
MODULE_DESCRIPTION("LM73 driver");
MODULE_LICENSE("GPL");
module_init(sensors_lm73_init);
module_exit(sensors_lm73_exit);