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linux-sg2042/drivers/hwmon/w83l785ts.c

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/*
* w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
* Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
*
* Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
* by Winbond. It reports a single external temperature with a 1 deg
* resolution and a 3 deg accuracy. Datasheet can be obtained from
* Winbond's website at:
* http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
*
* Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
* <khali@linux-fr.org>.
*
* Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
* error handling mechanism.
*
* 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.
*/
#include <linux/module.h>
#include <linux/delay.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>
/* How many retries on register read error */
#define MAX_RETRIES 5
/*
* Address to scan
* Address is fully defined internally and cannot be changed.
*/
static unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
/*
* Insmod parameters
*/
I2C_CLIENT_INSMOD_1(w83l785ts);
/*
* The W83L785TS-S registers
* Manufacturer ID is 0x5CA3 for Winbond.
*/
#define W83L785TS_REG_MAN_ID1 0x4D
#define W83L785TS_REG_MAN_ID2 0x4C
#define W83L785TS_REG_CHIP_ID 0x4E
#define W83L785TS_REG_CONFIG 0x40
#define W83L785TS_REG_TYPE 0x52
#define W83L785TS_REG_TEMP 0x27
#define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */
/*
* Conversions
* The W83L785TS-S uses signed 8-bit values.
*/
#define TEMP_FROM_REG(val) ((val) * 1000)
/*
* Functions declaration
*/
static int w83l785ts_attach_adapter(struct i2c_adapter *adapter);
static int w83l785ts_detect(struct i2c_adapter *adapter, int address,
int kind);
static int w83l785ts_detach_client(struct i2c_client *client);
static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);
/*
* Driver data (common to all clients)
*/
static struct i2c_driver w83l785ts_driver = {
.driver = {
.name = "w83l785ts",
},
.id = I2C_DRIVERID_W83L785TS,
.attach_adapter = w83l785ts_attach_adapter,
.detach_client = w83l785ts_detach_client,
};
/*
* Client data (each client gets its own)
*/
struct w83l785ts_data {
struct i2c_client client;
struct device *hwmon_dev;
struct mutex update_lock;
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
/* registers values */
s8 temp[2]; /* 0: input
1: critical limit */
};
/*
* Sysfs stuff
*/
static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct w83l785ts_data *data = w83l785ts_update_device(dev);
return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);
/*
* Real code
*/
static int w83l785ts_attach_adapter(struct i2c_adapter *adapter)
{
if (!(adapter->class & I2C_CLASS_HWMON))
return 0;
return i2c_probe(adapter, &addr_data, w83l785ts_detect);
}
/*
* The following function does more than just detection. If detection
* succeeds, it also registers the new chip.
*/
static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *new_client;
struct w83l785ts_data *data;
int err = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
goto exit;
if (!(data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
/* The common I2C client data is placed right before the
* W83L785TS-specific data. */
new_client = &data->client;
i2c_set_clientdata(new_client, data);
new_client->addr = address;
new_client->adapter = adapter;
new_client->driver = &w83l785ts_driver;
new_client->flags = 0;
/*
* Now we do the remaining detection. A negative kind means that
* the driver was loaded with no force parameter (default), so we
* must both detect and identify the chip (actually there is only
* one possible kind of chip for now, W83L785TS-S). A zero kind means
* that the driver was loaded with the force parameter, the detection
* step shall be skipped. A positive kind means that the driver
* was loaded with the force parameter and a given kind of chip is
* requested, so both the detection and the identification steps
* are skipped.
*/
if (kind < 0) { /* detection */
if (((w83l785ts_read_value(new_client,
W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00)
|| ((w83l785ts_read_value(new_client,
W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) {
dev_dbg(&adapter->dev,
"W83L785TS-S detection failed at 0x%02x.\n",
address);
goto exit_free;
}
}
if (kind <= 0) { /* identification */
u16 man_id;
u8 chip_id;
man_id = (w83l785ts_read_value(new_client,
W83L785TS_REG_MAN_ID1, 0) << 8) +
w83l785ts_read_value(new_client,
W83L785TS_REG_MAN_ID2, 0);
chip_id = w83l785ts_read_value(new_client,
W83L785TS_REG_CHIP_ID, 0);
if (man_id == 0x5CA3) { /* Winbond */
if (chip_id == 0x70) { /* W83L785TS-S */
kind = w83l785ts;
}
}
if (kind <= 0) { /* identification failed */
dev_info(&adapter->dev,
"Unsupported chip (man_id=0x%04X, "
"chip_id=0x%02X).\n", man_id, chip_id);
goto exit_free;
}
}
/* We can fill in the remaining client fields. */
strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE);
data->valid = 0;
mutex_init(&data->update_lock);
/* Default values in case the first read fails (unlikely). */
data->temp[1] = data->temp[0] = 0;
/* Tell the I2C layer a new client has arrived. */
if ((err = i2c_attach_client(new_client)))
goto exit_free;
/*
* Initialize the W83L785TS chip
* Nothing yet, assume it is already started.
*/
err = device_create_file(&new_client->dev,
&sensor_dev_attr_temp1_input.dev_attr);
if (err)
goto exit_remove;
err = device_create_file(&new_client->dev,
&sensor_dev_attr_temp1_max.dev_attr);
if (err)
goto exit_remove;
/* Register sysfs hooks */
data->hwmon_dev = hwmon_device_register(&new_client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
return 0;
exit_remove:
device_remove_file(&new_client->dev,
&sensor_dev_attr_temp1_input.dev_attr);
device_remove_file(&new_client->dev,
&sensor_dev_attr_temp1_max.dev_attr);
i2c_detach_client(new_client);
exit_free:
kfree(data);
exit:
return err;
}
static int w83l785ts_detach_client(struct i2c_client *client)
{
struct w83l785ts_data *data = i2c_get_clientdata(client);
int err;
hwmon_device_unregister(data->hwmon_dev);
device_remove_file(&client->dev,
&sensor_dev_attr_temp1_input.dev_attr);
device_remove_file(&client->dev,
&sensor_dev_attr_temp1_max.dev_attr);
if ((err = i2c_detach_client(client)))
return err;
kfree(data);
return 0;
}
static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
{
int value, i;
/* Frequent read errors have been reported on Asus boards, so we
* retry on read errors. If it still fails (unlikely), return the
* default value requested by the caller. */
for (i = 1; i <= MAX_RETRIES; i++) {
value = i2c_smbus_read_byte_data(client, reg);
if (value >= 0) {
dev_dbg(&client->dev, "Read 0x%02x from register "
"0x%02x.\n", value, reg);
return value;
}
dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i);
msleep(i);
}
dev_err(&client->dev, "Couldn't read value from register 0x%02x. "
"Please report.\n", reg);
return defval;
}
static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct w83l785ts_data *data = i2c_get_clientdata(client);
mutex_lock(&data->update_lock);
if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
dev_dbg(&client->dev, "Updating w83l785ts data.\n");
data->temp[0] = w83l785ts_read_value(client,
W83L785TS_REG_TEMP, data->temp[0]);
data->temp[1] = w83l785ts_read_value(client,
W83L785TS_REG_TEMP_OVER, data->temp[1]);
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
static int __init sensors_w83l785ts_init(void)
{
return i2c_add_driver(&w83l785ts_driver);
}
static void __exit sensors_w83l785ts_exit(void)
{
i2c_del_driver(&w83l785ts_driver);
}
MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("W83L785TS-S driver");
MODULE_LICENSE("GPL");
module_init(sensors_w83l785ts_init);
module_exit(sensors_w83l785ts_exit);
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