|  | /* 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/of_device.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); | 
|  |  | 
|  | static const struct of_device_id tmp421_of_match[] = { | 
|  | { | 
|  | .compatible = "ti,tmp421", | 
|  | .data = (void *)2 | 
|  | }, | 
|  | { | 
|  | .compatible = "ti,tmp422", | 
|  | .data = (void *)3 | 
|  | }, | 
|  | { | 
|  | .compatible = "ti,tmp423", | 
|  | .data = (void *)4 | 
|  | }, | 
|  | { | 
|  | .compatible = "ti,tmp441", | 
|  | .data = (void *)2 | 
|  | }, | 
|  | { | 
|  | .compatible = "ti,tmp442", | 
|  | .data = (void *)3 | 
|  | }, | 
|  | { }, | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(of, tmp421_of_match); | 
|  |  | 
|  | struct tmp421_data { | 
|  | struct i2c_client *client; | 
|  | struct mutex update_lock; | 
|  | u32 temp_config[5]; | 
|  | struct hwmon_channel_info temp_info; | 
|  | const struct hwmon_channel_info *info[2]; | 
|  | struct hwmon_chip_info chip; | 
|  | char valid; | 
|  | unsigned long last_updated; | 
|  | unsigned long 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 int tmp421_read(struct device *dev, enum hwmon_sensor_types type, | 
|  | u32 attr, int channel, long *val) | 
|  | { | 
|  | struct tmp421_data *tmp421 = tmp421_update_device(dev); | 
|  |  | 
|  | switch (attr) { | 
|  | case hwmon_temp_input: | 
|  | if (tmp421->config & TMP421_CONFIG_RANGE) | 
|  | *val = temp_from_u16(tmp421->temp[channel]); | 
|  | else | 
|  | *val = temp_from_s16(tmp421->temp[channel]); | 
|  | return 0; | 
|  | case hwmon_temp_fault: | 
|  | /* | 
|  | * The OPEN bit signals a fault. This is bit 0 of the temperature | 
|  | * register (low byte). | 
|  | */ | 
|  | *val = tmp421->temp[channel] & 0x01; | 
|  | return 0; | 
|  | default: | 
|  | return -EOPNOTSUPP; | 
|  | } | 
|  |  | 
|  | } | 
|  |  | 
|  | static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type, | 
|  | u32 attr, int channel) | 
|  | { | 
|  | switch (attr) { | 
|  | case hwmon_temp_fault: | 
|  | if (channel == 0) | 
|  | return 0; | 
|  | return S_IRUGO; | 
|  | case hwmon_temp_input: | 
|  | return S_IRUGO; | 
|  | default: | 
|  | return 0; | 
|  | } | 
|  | } | 
|  |  | 
|  | 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 const struct hwmon_ops tmp421_ops = { | 
|  | .is_visible = tmp421_is_visible, | 
|  | .read = tmp421_read, | 
|  | }; | 
|  |  | 
|  | 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 i, err; | 
|  |  | 
|  | data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL); | 
|  | if (!data) | 
|  | return -ENOMEM; | 
|  |  | 
|  | mutex_init(&data->update_lock); | 
|  | if (client->dev.of_node) | 
|  | data->channels = (unsigned long) | 
|  | of_device_get_match_data(&client->dev); | 
|  | else | 
|  | data->channels = id->driver_data; | 
|  | data->client = client; | 
|  |  | 
|  | err = tmp421_init_client(client); | 
|  | if (err) | 
|  | return err; | 
|  |  | 
|  | for (i = 0; i < data->channels; i++) | 
|  | data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT; | 
|  |  | 
|  | data->chip.ops = &tmp421_ops; | 
|  | data->chip.info = data->info; | 
|  |  | 
|  | data->info[0] = &data->temp_info; | 
|  |  | 
|  | data->temp_info.type = hwmon_temp; | 
|  | data->temp_info.config = data->temp_config; | 
|  |  | 
|  | hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, | 
|  | data, | 
|  | &data->chip, | 
|  | NULL); | 
|  | return PTR_ERR_OR_ZERO(hwmon_dev); | 
|  | } | 
|  |  | 
|  | static struct i2c_driver tmp421_driver = { | 
|  | .class = I2C_CLASS_HWMON, | 
|  | .driver = { | 
|  | .name	= "tmp421", | 
|  | .of_match_table = of_match_ptr(tmp421_of_match), | 
|  | }, | 
|  | .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"); |