3 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
4 * Preliminary support by:
5 * Melvin Rook, Raymond Ng
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
19 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
20 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/jiffies.h>
27 #include <linux/i2c.h>
28 #include <linux/hwmon.h>
29 #include <linux/hwmon-sysfs.h>
30 #include <linux/err.h>
31 #include <linux/mutex.h>
32 #include <linux/of_device.h>
33 #include <linux/sysfs.h>
35 /* Addresses to scan */
36 static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
39 enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
41 /* The TMP421 registers */
42 #define TMP421_STATUS_REG 0x08
43 #define TMP421_CONFIG_REG_1 0x09
44 #define TMP421_CONVERSION_RATE_REG 0x0B
45 #define TMP421_MANUFACTURER_ID_REG 0xFE
46 #define TMP421_DEVICE_ID_REG 0xFF
48 static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
49 static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
52 #define TMP421_CONFIG_SHUTDOWN 0x40
53 #define TMP421_CONFIG_RANGE 0x04
55 /* Manufacturer / Device ID's */
56 #define TMP421_MANUFACTURER_ID 0x55
57 #define TMP421_DEVICE_ID 0x21
58 #define TMP422_DEVICE_ID 0x22
59 #define TMP423_DEVICE_ID 0x23
60 #define TMP441_DEVICE_ID 0x41
61 #define TMP442_DEVICE_ID 0x42
63 static const struct i2c_device_id tmp421_id[] = {
71 MODULE_DEVICE_TABLE(i2c, tmp421_id);
73 static const struct of_device_id tmp421_of_match[] = {
75 .compatible = "ti,tmp421",
79 .compatible = "ti,tmp422",
83 .compatible = "ti,tmp423",
87 .compatible = "ti,tmp441",
91 .compatible = "ti,tmp442",
96 MODULE_DEVICE_TABLE(of, tmp421_of_match);
99 struct i2c_client *client;
100 struct mutex update_lock;
102 struct hwmon_channel_info temp_info;
103 const struct hwmon_channel_info *info[2];
104 struct hwmon_chip_info chip;
106 unsigned long last_updated;
107 unsigned long channels;
112 static int temp_from_raw(u16 reg, bool extended)
114 /* Mask out status bits */
115 int temp = reg & ~0xf;
118 temp = temp - 64 * 256;
122 return DIV_ROUND_CLOSEST(temp * 1000, 256);
125 static struct tmp421_data *tmp421_update_device(struct device *dev)
127 struct tmp421_data *data = dev_get_drvdata(dev);
128 struct i2c_client *client = data->client;
131 mutex_lock(&data->update_lock);
133 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
134 data->config = i2c_smbus_read_byte_data(client,
135 TMP421_CONFIG_REG_1);
137 for (i = 0; i < data->channels; i++) {
138 data->temp[i] = i2c_smbus_read_byte_data(client,
139 TMP421_TEMP_MSB[i]) << 8;
140 data->temp[i] |= i2c_smbus_read_byte_data(client,
143 data->last_updated = jiffies;
147 mutex_unlock(&data->update_lock);
152 static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
153 u32 attr, int channel, long *val)
155 struct tmp421_data *tmp421 = tmp421_update_device(dev);
158 case hwmon_temp_input:
159 *val = temp_from_raw(tmp421->temp[channel],
160 tmp421->config & TMP421_CONFIG_RANGE);
162 case hwmon_temp_fault:
164 * The OPEN bit signals a fault. This is bit 0 of the temperature
165 * register (low byte).
167 *val = tmp421->temp[channel] & 0x01;
175 static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
176 u32 attr, int channel)
179 case hwmon_temp_fault:
183 case hwmon_temp_input:
190 static int tmp421_init_client(struct i2c_client *client)
192 int config, config_orig;
194 /* Set the conversion rate to 2 Hz */
195 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
197 /* Start conversions (disable shutdown if necessary) */
198 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
200 dev_err(&client->dev,
201 "Could not read configuration register (%d)\n", config);
205 config_orig = config;
206 config &= ~TMP421_CONFIG_SHUTDOWN;
208 if (config != config_orig) {
209 dev_info(&client->dev, "Enable monitoring chip\n");
210 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
216 static int tmp421_detect(struct i2c_client *client,
217 struct i2c_board_info *info)
220 struct i2c_adapter *adapter = client->adapter;
221 const char * const names[] = { "TMP421", "TMP422", "TMP423",
222 "TMP441", "TMP442" };
223 int addr = client->addr;
226 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
229 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
230 if (reg != TMP421_MANUFACTURER_ID)
233 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
237 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
241 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
243 case TMP421_DEVICE_ID:
246 case TMP422_DEVICE_ID:
251 case TMP423_DEVICE_ID:
252 if (addr != 0x4c && addr != 0x4d)
256 case TMP441_DEVICE_ID:
259 case TMP442_DEVICE_ID:
260 if (addr != 0x4c && addr != 0x4d)
268 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
269 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
270 names[kind], client->addr);
275 static const struct hwmon_ops tmp421_ops = {
276 .is_visible = tmp421_is_visible,
280 static int tmp421_probe(struct i2c_client *client,
281 const struct i2c_device_id *id)
283 struct device *dev = &client->dev;
284 struct device *hwmon_dev;
285 struct tmp421_data *data;
288 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
292 mutex_init(&data->update_lock);
293 if (client->dev.of_node)
294 data->channels = (unsigned long)
295 of_device_get_match_data(&client->dev);
297 data->channels = id->driver_data;
298 data->client = client;
300 err = tmp421_init_client(client);
304 for (i = 0; i < data->channels; i++)
305 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
307 data->chip.ops = &tmp421_ops;
308 data->chip.info = data->info;
310 data->info[0] = &data->temp_info;
312 data->temp_info.type = hwmon_temp;
313 data->temp_info.config = data->temp_config;
315 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
319 return PTR_ERR_OR_ZERO(hwmon_dev);
322 static struct i2c_driver tmp421_driver = {
323 .class = I2C_CLASS_HWMON,
326 .of_match_table = of_match_ptr(tmp421_of_match),
328 .probe = tmp421_probe,
329 .id_table = tmp421_id,
330 .detect = tmp421_detect,
331 .address_list = normal_i2c,
334 module_i2c_driver(tmp421_driver);
336 MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
337 MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
338 MODULE_LICENSE("GPL");