1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
5 * Preliminary support by:
6 * Melvin Rook, Raymond Ng
10 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
11 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/jiffies.h>
18 #include <linux/i2c.h>
19 #include <linux/hwmon.h>
20 #include <linux/hwmon-sysfs.h>
21 #include <linux/err.h>
22 #include <linux/mutex.h>
23 #include <linux/of_device.h>
24 #include <linux/sysfs.h>
26 /* Addresses to scan */
27 static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
30 enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
32 /* The TMP421 registers */
33 #define TMP421_STATUS_REG 0x08
34 #define TMP421_CONFIG_REG_1 0x09
35 #define TMP421_CONVERSION_RATE_REG 0x0B
36 #define TMP421_MANUFACTURER_ID_REG 0xFE
37 #define TMP421_DEVICE_ID_REG 0xFF
39 static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
40 static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
43 #define TMP421_CONFIG_SHUTDOWN 0x40
44 #define TMP421_CONFIG_RANGE 0x04
46 /* Manufacturer / Device ID's */
47 #define TMP421_MANUFACTURER_ID 0x55
48 #define TMP421_DEVICE_ID 0x21
49 #define TMP422_DEVICE_ID 0x22
50 #define TMP423_DEVICE_ID 0x23
51 #define TMP441_DEVICE_ID 0x41
52 #define TMP442_DEVICE_ID 0x42
54 static const struct i2c_device_id tmp421_id[] = {
62 MODULE_DEVICE_TABLE(i2c, tmp421_id);
64 static const struct of_device_id __maybe_unused tmp421_of_match[] = {
66 .compatible = "ti,tmp421",
70 .compatible = "ti,tmp422",
74 .compatible = "ti,tmp423",
78 .compatible = "ti,tmp441",
82 .compatible = "ti,tmp442",
87 MODULE_DEVICE_TABLE(of, tmp421_of_match);
90 struct i2c_client *client;
91 struct mutex update_lock;
93 struct hwmon_channel_info temp_info;
94 const struct hwmon_channel_info *info[2];
95 struct hwmon_chip_info chip;
97 unsigned long last_updated;
98 unsigned long channels;
103 static int temp_from_raw(u16 reg, bool extended)
105 /* Mask out status bits */
106 int temp = reg & ~0xf;
109 temp = temp - 64 * 256;
113 return DIV_ROUND_CLOSEST(temp * 1000, 256);
116 static int tmp421_update_device(struct tmp421_data *data)
118 struct i2c_client *client = data->client;
122 mutex_lock(&data->update_lock);
124 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
126 ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
131 for (i = 0; i < data->channels; i++) {
132 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
135 data->temp[i] = ret << 8;
137 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
140 data->temp[i] |= ret;
142 data->last_updated = jiffies;
147 mutex_unlock(&data->update_lock);
157 static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
158 u32 attr, int channel, long *val)
160 struct tmp421_data *tmp421 = dev_get_drvdata(dev);
163 ret = tmp421_update_device(tmp421);
168 case hwmon_temp_input:
169 *val = temp_from_raw(tmp421->temp[channel],
170 tmp421->config & TMP421_CONFIG_RANGE);
172 case hwmon_temp_fault:
174 * Any of OPEN or /PVLD bits indicate a hardware mulfunction
175 * and the conversion result may be incorrect
177 *val = !!(tmp421->temp[channel] & 0x03);
185 static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
186 u32 attr, int channel)
189 case hwmon_temp_fault:
190 case hwmon_temp_input:
197 static int tmp421_init_client(struct i2c_client *client)
199 int config, config_orig;
201 /* Set the conversion rate to 2 Hz */
202 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
204 /* Start conversions (disable shutdown if necessary) */
205 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
207 dev_err(&client->dev,
208 "Could not read configuration register (%d)\n", config);
212 config_orig = config;
213 config &= ~TMP421_CONFIG_SHUTDOWN;
215 if (config != config_orig) {
216 dev_info(&client->dev, "Enable monitoring chip\n");
217 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
223 static int tmp421_detect(struct i2c_client *client,
224 struct i2c_board_info *info)
227 struct i2c_adapter *adapter = client->adapter;
228 static const char * const names[] = {
229 "TMP421", "TMP422", "TMP423",
232 int addr = client->addr;
235 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
238 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
239 if (reg != TMP421_MANUFACTURER_ID)
242 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
246 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
250 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
252 case TMP421_DEVICE_ID:
255 case TMP422_DEVICE_ID:
260 case TMP423_DEVICE_ID:
261 if (addr != 0x4c && addr != 0x4d)
265 case TMP441_DEVICE_ID:
268 case TMP442_DEVICE_ID:
269 if (addr != 0x4c && addr != 0x4d)
277 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
278 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
279 names[kind], client->addr);
284 static const struct hwmon_ops tmp421_ops = {
285 .is_visible = tmp421_is_visible,
289 static int tmp421_probe(struct i2c_client *client)
291 struct device *dev = &client->dev;
292 struct device *hwmon_dev;
293 struct tmp421_data *data;
296 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
300 mutex_init(&data->update_lock);
301 if (client->dev.of_node)
302 data->channels = (unsigned long)
303 of_device_get_match_data(&client->dev);
305 data->channels = i2c_match_id(tmp421_id, client)->driver_data;
306 data->client = client;
308 err = tmp421_init_client(client);
312 for (i = 0; i < data->channels; i++)
313 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
315 data->chip.ops = &tmp421_ops;
316 data->chip.info = data->info;
318 data->info[0] = &data->temp_info;
320 data->temp_info.type = hwmon_temp;
321 data->temp_info.config = data->temp_config;
323 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
327 return PTR_ERR_OR_ZERO(hwmon_dev);
330 static struct i2c_driver tmp421_driver = {
331 .class = I2C_CLASS_HWMON,
334 .of_match_table = of_match_ptr(tmp421_of_match),
336 .probe_new = tmp421_probe,
337 .id_table = tmp421_id,
338 .detect = tmp421_detect,
339 .address_list = normal_i2c,
342 module_i2c_driver(tmp421_driver);
344 MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
345 MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
346 MODULE_LICENSE("GPL");