diff options
Diffstat (limited to 'drivers/hwmon/tmp421.c')
| -rw-r--r-- | drivers/hwmon/tmp421.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c new file mode 100644 index 000000000..85d48d808 --- /dev/null +++ b/drivers/hwmon/tmp421.c @@ -0,0 +1,332 @@ +/* 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. + */ + +/* + * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC. + * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442 + */ + +#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 const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, + I2C_CLIENT_END }; + +enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 }; + +/* The TMP421 registers */ +#define TMP421_STATUS_REG 0x08 +#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 +#define TMP441_DEVICE_ID 0x41 +#define TMP442_DEVICE_ID 0x42 + +static const struct i2c_device_id tmp421_id[] = { + { "tmp421", 2 }, + { "tmp422", 3 }, + { "tmp423", 4 }, + { "tmp441", 2 }, + { "tmp442", 3 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tmp421_id); + +struct tmp421_data { + struct i2c_client *client; + 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 tmp421_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->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 umode_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 const struct attribute_group *tmp421_groups[] = { + &tmp421_group, + NULL +}; + +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 config; + } + + 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 * const names[] = { "TMP421", "TMP422", "TMP423", + "TMP441", "TMP442" }; + int addr = client->addr; + 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_CONVERSION_RATE_REG); + if (reg & 0xf8) + return -ENODEV; + + reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG); + if (reg & 0x7f) + 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: + if (addr == 0x2a) + return -ENODEV; + kind = tmp422; + break; + case TMP423_DEVICE_ID: + if (addr != 0x4c && addr != 0x4d) + return -ENODEV; + kind = tmp423; + break; + case TMP441_DEVICE_ID: + kind = tmp441; + break; + case TMP442_DEVICE_ID: + if (addr != 0x4c && addr != 0x4d) + return -ENODEV; + kind = tmp442; + 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 device *dev = &client->dev; + struct device *hwmon_dev; + struct tmp421_data *data; + int err; + + data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + mutex_init(&data->update_lock); + data->channels = id->driver_data; + data->client = client; + + err = tmp421_init_client(client); + if (err) + return err; + + hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, + data, tmp421_groups); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static struct i2c_driver tmp421_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "tmp421", + }, + .probe = tmp421_probe, + .id_table = tmp421_id, + .detect = tmp421_detect, + .address_list = normal_i2c, +}; + +module_i2c_driver(tmp421_driver); + +MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>"); +MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver"); +MODULE_LICENSE("GPL"); |