/* * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware * monitoring * Copyright (C) 2003-2009 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 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 *new_client, const struct i2c_device_id *id) { struct w83l785ts_data *data; int err = 0; data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL); if (!data) { err = -ENOMEM; goto exit; } i2c_set_clientdata(new_client, data); data->valid = 0; mutex_init(&data->update_lock); /* Default values in case the first read fails (unlikely). */ data->temp[1] = data->temp[0] = 0; /* * 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); kfree(data); exit: 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); kfree(data); 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; } 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);