diff options
Diffstat (limited to 'drivers/hwmon/w83l785ts.c')
| -rw-r--r-- | drivers/hwmon/w83l785ts.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/drivers/hwmon/w83l785ts.c b/drivers/hwmon/w83l785ts.c new file mode 100644 index 000000000..ac3043122 --- /dev/null +++ b/drivers/hwmon/w83l785ts.c @@ -0,0 +1,300 @@ +/* + * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware + * monitoring + * Copyright (C) 2003-2009 Jean Delvare <jdelvare@suse.de> + * + * 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 + * <jdelvare@suse.de>. + * + * 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 const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END }; + +/* + * 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_probe(struct i2c_client *client, + const struct i2c_device_id *id); +static int w83l785ts_detect(struct i2c_client *client, + struct i2c_board_info *info); +static int w83l785ts_remove(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 const struct i2c_device_id w83l785ts_id[] = { + { "w83l785ts", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, w83l785ts_id); + +static struct i2c_driver w83l785ts_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "w83l785ts", + }, + .probe = w83l785ts_probe, + .remove = w83l785ts_remove, + .id_table = w83l785ts_id, + .detect = w83l785ts_detect, + .address_list = normal_i2c, +}; + +/* + * Client data (each client gets its own) + */ + +struct w83l785ts_data { + 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 + */ + +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int w83l785ts_detect(struct i2c_client *client, + struct i2c_board_info *info) +{ + struct i2c_adapter *adapter = client->adapter; + u16 man_id; + u8 chip_id; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -ENODEV; + + /* detection */ + if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80) + || (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) { + dev_dbg(&adapter->dev, + "W83L785TS-S detection failed at 0x%02x\n", + client->addr); + return -ENODEV; + } + + /* Identification */ + man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8) + + w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0); + chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0); + + if (man_id != 0x5CA3 /* Winbond */ + || chip_id != 0x70) { /* W83L785TS-S */ + dev_dbg(&adapter->dev, + "Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n", + man_id, chip_id); + return -ENODEV; + } + + strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE); + + return 0; +} + +static int w83l785ts_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct w83l785ts_data *data; + struct device *dev = &client->dev; + int err; + + data = devm_kzalloc(dev, sizeof(struct w83l785ts_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + /* + * Initialize the W83L785TS chip + * Nothing yet, assume it is already started. + */ + + err = device_create_file(dev, &sensor_dev_attr_temp1_input.dev_attr); + if (err) + return err; + + err = device_create_file(dev, &sensor_dev_attr_temp1_max.dev_attr); + if (err) + goto exit_remove; + + /* Register sysfs hooks */ + data->hwmon_dev = hwmon_device_register(dev); + if (IS_ERR(data->hwmon_dev)) { + err = PTR_ERR(data->hwmon_dev); + goto exit_remove; + } + + return 0; + +exit_remove: + device_remove_file(dev, &sensor_dev_attr_temp1_input.dev_attr); + device_remove_file(dev, &sensor_dev_attr_temp1_max.dev_attr); + return err; +} + +static int w83l785ts_remove(struct i2c_client *client) +{ + struct w83l785ts_data *data = i2c_get_clientdata(client); + + 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); + + return 0; +} + +static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval) +{ + int value, i; + struct device *dev; + const char *prefix; + + /* + * We might be called during detection, at which point the client + * isn't yet fully initialized, so we can't use dev_dbg on it + */ + if (i2c_get_clientdata(client)) { + dev = &client->dev; + prefix = ""; + } else { + dev = &client->adapter->dev; + prefix = "w83l785ts: "; + } + + /* + * 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(dev, "%sRead 0x%02x from register 0x%02x.\n", + prefix, value, reg); + return value; + } + dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i); + msleep(i); + } + + dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix, + 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; +} + +module_i2c_driver(w83l785ts_driver); + +MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); +MODULE_DESCRIPTION("W83L785TS-S driver"); +MODULE_LICENSE("GPL"); |