| /* 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. |
| * |
| * 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. |
| */ |
| |
| /* |
| * 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"); |