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linux/drivers/hwmon/tmp421.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

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/* tmp421.c
*
* Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
* Preliminary support by:
* Melvin Rook, Raymond Ng
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
* Supported models: TMP421, TMP422, TMP423
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
I2C_CLIENT_END };
enum chips { tmp421, tmp422, tmp423 };
/* The TMP421 registers */
#define TMP421_CONFIG_REG_1 0x09
#define TMP421_CONVERSION_RATE_REG 0x0B
#define TMP421_MANUFACTURER_ID_REG 0xFE
#define TMP421_DEVICE_ID_REG 0xFF
static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
/* Flags */
#define TMP421_CONFIG_SHUTDOWN 0x40
#define TMP421_CONFIG_RANGE 0x04
/* Manufacturer / Device ID's */
#define TMP421_MANUFACTURER_ID 0x55
#define TMP421_DEVICE_ID 0x21
#define TMP422_DEVICE_ID 0x22
#define TMP423_DEVICE_ID 0x23
static const struct i2c_device_id tmp421_id[] = {
{ "tmp421", 2 },
{ "tmp422", 3 },
{ "tmp423", 4 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tmp421_id);
struct tmp421_data {
struct device *hwmon_dev;
struct mutex update_lock;
char valid;
unsigned long last_updated;
int channels;
u8 config;
s16 temp[4];
};
static int temp_from_s16(s16 reg)
{
/* Mask out status bits */
int temp = reg & ~0xf;
return (temp * 1000 + 128) / 256;
}
static int temp_from_u16(u16 reg)
{
/* Mask out status bits */
int temp = reg & ~0xf;
/* Add offset for extended temperature range. */
temp -= 64 * 256;
return (temp * 1000 + 128) / 256;
}
static struct tmp421_data *tmp421_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tmp421_data *data = i2c_get_clientdata(client);
int i;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
data->config = i2c_smbus_read_byte_data(client,
TMP421_CONFIG_REG_1);
for (i = 0; i < data->channels; i++) {
data->temp[i] = i2c_smbus_read_byte_data(client,
TMP421_TEMP_MSB[i]) << 8;
data->temp[i] |= i2c_smbus_read_byte_data(client,
TMP421_TEMP_LSB[i]);
}
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
static ssize_t show_temp_value(struct device *dev,
struct device_attribute *devattr, char *buf)
{
int index = to_sensor_dev_attr(devattr)->index;
struct tmp421_data *data = tmp421_update_device(dev);
int temp;
mutex_lock(&data->update_lock);
if (data->config & TMP421_CONFIG_RANGE)
temp = temp_from_u16(data->temp[index]);
else
temp = temp_from_s16(data->temp[index]);
mutex_unlock(&data->update_lock);
return sprintf(buf, "%d\n", temp);
}
static ssize_t show_fault(struct device *dev,
struct device_attribute *devattr, char *buf)
{
int index = to_sensor_dev_attr(devattr)->index;
struct tmp421_data *data = tmp421_update_device(dev);
/*
* The OPEN bit signals a fault. This is bit 0 of the temperature
* register (low byte).
*/
if (data->temp[index] & 0x01)
return sprintf(buf, "1\n");
else
return sprintf(buf, "0\n");
}
static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct tmp421_data *data = dev_get_drvdata(dev);
struct device_attribute *devattr;
unsigned int index;
devattr = container_of(a, struct device_attribute, attr);
index = to_sensor_dev_attr(devattr)->index;
if (index < data->channels)
return a->mode;
return 0;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
static struct attribute *tmp421_attr[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp2_input.dev_attr.attr,
&sensor_dev_attr_temp2_fault.dev_attr.attr,
&sensor_dev_attr_temp3_input.dev_attr.attr,
&sensor_dev_attr_temp3_fault.dev_attr.attr,
&sensor_dev_attr_temp4_input.dev_attr.attr,
&sensor_dev_attr_temp4_fault.dev_attr.attr,
NULL
};
static const struct attribute_group tmp421_group = {
.attrs = tmp421_attr,
.is_visible = tmp421_is_visible,
};
static int tmp421_init_client(struct i2c_client *client)
{
int config, config_orig;
/* Set the conversion rate to 2 Hz */
i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
/* Start conversions (disable shutdown if necessary) */
config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
if (config < 0) {
dev_err(&client->dev, "Could not read configuration"
" register (%d)\n", config);
return -ENODEV;
}
config_orig = config;
config &= ~TMP421_CONFIG_SHUTDOWN;
if (config != config_orig) {
dev_info(&client->dev, "Enable monitoring chip\n");
i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
}
return 0;
}
static int tmp421_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
enum chips kind;
struct i2c_adapter *adapter = client->adapter;
const char *names[] = { "TMP421", "TMP422", "TMP423" };
u8 reg;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
if (reg != TMP421_MANUFACTURER_ID)
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
switch (reg) {
case TMP421_DEVICE_ID:
kind = tmp421;
break;
case TMP422_DEVICE_ID:
kind = tmp422;
break;
case TMP423_DEVICE_ID:
kind = tmp423;
break;
default:
return -ENODEV;
}
strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
names[kind], client->addr);
return 0;
}
static int tmp421_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tmp421_data *data;
int err;
data = kzalloc(sizeof(struct tmp421_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
data->channels = id->driver_data;
err = tmp421_init_client(client);
if (err)
goto exit_free;
err = sysfs_create_group(&client->dev.kobj, &tmp421_group);
if (err)
goto exit_free;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
data->hwmon_dev = NULL;
goto exit_remove;
}
return 0;
exit_remove:
sysfs_remove_group(&client->dev.kobj, &tmp421_group);
exit_free:
kfree(data);
return err;
}
static int tmp421_remove(struct i2c_client *client)
{
struct tmp421_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &tmp421_group);
kfree(data);
return 0;
}
static struct i2c_driver tmp421_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "tmp421",
},
.probe = tmp421_probe,
.remove = tmp421_remove,
.id_table = tmp421_id,
.detect = tmp421_detect,
.address_list = normal_i2c,
};
static int __init tmp421_init(void)
{
return i2c_add_driver(&tmp421_driver);
}
static void __exit tmp421_exit(void)
{
i2c_del_driver(&tmp421_driver);
}
MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor"
" driver");
MODULE_LICENSE("GPL");
module_init(tmp421_init);
module_exit(tmp421_exit);
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