diff options
Diffstat (limited to 'drivers/i2c/chips/w83l785ts.c')
| -rw-r--r-- | drivers/i2c/chips/w83l785ts.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/i2c/chips/w83l785ts.c b/drivers/i2c/chips/w83l785ts.c new file mode 100644 index 000000000000..59bbc5881fa6 --- /dev/null +++ b/drivers/i2c/chips/w83l785ts.c @@ -0,0 +1,329 @@ +/* + * 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/config.h> +#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/i2c-sensor.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 }; +static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; + +/* + * Insmod parameters + */ + +SENSORS_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 & 0x80 ? val-0x100 : 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 = { + .owner = THIS_MODULE, + .name = "w83l785ts", + .id = I2C_DRIVERID_W83L785TS, + .flags = I2C_DF_NOTIFY, + .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 semaphore update_lock; + char valid; /* zero until following fields are valid */ + unsigned long last_updated; /* in jiffies */ + + /* registers values */ + u8 temp, temp_over; +}; + +/* + * Sysfs stuff + */ + +static ssize_t show_temp(struct device *dev, char *buf) +{ + struct w83l785ts_data *data = w83l785ts_update_device(dev); + return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp)); +} + +static ssize_t show_temp_over(struct device *dev, char *buf) +{ + struct w83l785ts_data *data = w83l785ts_update_device(dev); + return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over)); +} + +static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); +static DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_over, NULL); + +/* + * Real code + */ + +static int w83l785ts_attach_adapter(struct i2c_adapter *adapter) +{ + if (!(adapter->class & I2C_CLASS_HWMON)) + return 0; + return i2c_detect(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 = kmalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) { + err = -ENOMEM; + goto exit; + } + memset(data, 0, sizeof(struct w83l785ts_data)); + + + /* 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; + init_MUTEX(&data->update_lock); + + /* Default values in case the first read fails (unlikely). */ + data->temp_over = data->temp = 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. + */ + + /* Register sysfs hooks */ + device_create_file(&new_client->dev, &dev_attr_temp1_input); + device_create_file(&new_client->dev, &dev_attr_temp1_max); + + return 0; + +exit_free: + kfree(data); +exit: + return err; +} + +static int w83l785ts_detach_client(struct i2c_client *client) +{ + int err; + + if ((err = i2c_detach_client(client))) { + dev_err(&client->dev, "Client deregistration failed, " + "client not detached.\n"); + return err; + } + + kfree(i2c_get_clientdata(client)); + 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); + + down(&data->update_lock); + + if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) { + dev_dbg(&client->dev, "Updating w83l785ts data.\n"); + data->temp = w83l785ts_read_value(client, + W83L785TS_REG_TEMP, data->temp); + data->temp_over = w83l785ts_read_value(client, + W83L785TS_REG_TEMP_OVER, data->temp_over); + + data->last_updated = jiffies; + data->valid = 1; + } + + up(&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); |