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1// SPDX-License-Identifier: GPL-2.0-or-later2/* tmp421.c3 *4 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>5 * Preliminary support by:6 * Melvin Rook, Raymond Ng7 */8 9/*10 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.11 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP44212 */13 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.h>24#include <linux/sysfs.h>25 26/* Addresses to scan */27static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,28 I2C_CLIENT_END };29 30enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };31 32#define MAX_CHANNELS 433/* The TMP421 registers */34#define TMP421_STATUS_REG 0x0835#define TMP421_CONFIG_REG_1 0x0936#define TMP421_CONFIG_REG_2 0x0A37#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))38#define TMP421_CONFIG_REG_REN_MASK GENMASK(6, 3)39#define TMP421_CONVERSION_RATE_REG 0x0B40#define TMP421_N_FACTOR_REG_1 0x2141#define TMP421_MANUFACTURER_ID_REG 0xFE42#define TMP421_DEVICE_ID_REG 0xFF43 44static const u8 TMP421_TEMP_MSB[MAX_CHANNELS] = { 0x00, 0x01, 0x02, 0x03 };45static const u8 TMP421_TEMP_LSB[MAX_CHANNELS] = { 0x10, 0x11, 0x12, 0x13 };46 47/* Flags */48#define TMP421_CONFIG_SHUTDOWN 0x4049#define TMP421_CONFIG_RANGE 0x0450 51/* Manufacturer / Device ID's */52#define TMP421_MANUFACTURER_ID 0x5553#define TMP421_DEVICE_ID 0x2154#define TMP422_DEVICE_ID 0x2255#define TMP423_DEVICE_ID 0x2356#define TMP441_DEVICE_ID 0x4157#define TMP442_DEVICE_ID 0x4258 59static const struct i2c_device_id tmp421_id[] = {60 { "tmp421", 2 },61 { "tmp422", 3 },62 { "tmp423", 4 },63 { "tmp441", 2 },64 { "tmp442", 3 },65 { }66};67MODULE_DEVICE_TABLE(i2c, tmp421_id);68 69static const struct of_device_id __maybe_unused tmp421_of_match[] = {70 {71 .compatible = "ti,tmp421",72 .data = (void *)273 },74 {75 .compatible = "ti,tmp422",76 .data = (void *)377 },78 {79 .compatible = "ti,tmp423",80 .data = (void *)481 },82 {83 .compatible = "ti,tmp441",84 .data = (void *)285 },86 {87 .compatible = "ti,tmp442",88 .data = (void *)389 },90 { },91};92MODULE_DEVICE_TABLE(of, tmp421_of_match);93 94struct tmp421_channel {95 const char *label;96 bool enabled;97 s16 temp;98};99 100struct tmp421_data {101 struct i2c_client *client;102 struct mutex update_lock;103 u32 temp_config[MAX_CHANNELS + 1];104 struct hwmon_channel_info temp_info;105 const struct hwmon_channel_info *info[2];106 struct hwmon_chip_info chip;107 bool valid;108 unsigned long last_updated;109 unsigned long channels;110 u8 config;111 struct tmp421_channel channel[MAX_CHANNELS];112};113 114static int temp_from_raw(u16 reg, bool extended)115{116 /* Mask out status bits */117 int temp = reg & ~0xf;118 119 if (extended)120 temp = temp - 64 * 256;121 else122 temp = (s16)temp;123 124 return DIV_ROUND_CLOSEST(temp * 1000, 256);125}126 127static int tmp421_update_device(struct tmp421_data *data)128{129 struct i2c_client *client = data->client;130 int ret = 0;131 int i;132 133 mutex_lock(&data->update_lock);134 135 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||136 !data->valid) {137 ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);138 if (ret < 0)139 goto exit;140 data->config = ret;141 142 for (i = 0; i < data->channels; i++) {143 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);144 if (ret < 0)145 goto exit;146 data->channel[i].temp = ret << 8;147 148 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);149 if (ret < 0)150 goto exit;151 data->channel[i].temp |= ret;152 }153 data->last_updated = jiffies;154 data->valid = true;155 }156 157exit:158 mutex_unlock(&data->update_lock);159 160 if (ret < 0) {161 data->valid = false;162 return ret;163 }164 165 return 0;166}167 168static int tmp421_enable_channels(struct tmp421_data *data)169{170 int err;171 struct i2c_client *client = data->client;172 struct device *dev = &client->dev;173 int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);174 int new, i;175 176 if (old < 0) {177 dev_err(dev, "error reading register, can't disable channels\n");178 return old;179 }180 181 new = old & ~TMP421_CONFIG_REG_REN_MASK;182 for (i = 0; i < data->channels; i++)183 if (data->channel[i].enabled)184 new |= TMP421_CONFIG_REG_REN(i);185 186 if (new == old)187 return 0;188 189 err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);190 if (err < 0)191 dev_err(dev, "error writing register, can't disable channels\n");192 193 return err;194}195 196static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,197 u32 attr, int channel, long *val)198{199 struct tmp421_data *tmp421 = dev_get_drvdata(dev);200 int ret = 0;201 202 ret = tmp421_update_device(tmp421);203 if (ret)204 return ret;205 206 switch (attr) {207 case hwmon_temp_input:208 if (!tmp421->channel[channel].enabled)209 return -ENODATA;210 *val = temp_from_raw(tmp421->channel[channel].temp,211 tmp421->config & TMP421_CONFIG_RANGE);212 return 0;213 case hwmon_temp_fault:214 if (!tmp421->channel[channel].enabled)215 return -ENODATA;216 /*217 * Any of OPEN or /PVLD bits indicate a hardware mulfunction218 * and the conversion result may be incorrect219 */220 *val = !!(tmp421->channel[channel].temp & 0x03);221 return 0;222 case hwmon_temp_enable:223 *val = tmp421->channel[channel].enabled;224 return 0;225 default:226 return -EOPNOTSUPP;227 }228 229}230 231static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,232 u32 attr, int channel, const char **str)233{234 struct tmp421_data *data = dev_get_drvdata(dev);235 236 *str = data->channel[channel].label;237 238 return 0;239}240 241static int tmp421_write(struct device *dev, enum hwmon_sensor_types type,242 u32 attr, int channel, long val)243{244 struct tmp421_data *data = dev_get_drvdata(dev);245 int ret;246 247 switch (attr) {248 case hwmon_temp_enable:249 data->channel[channel].enabled = val;250 ret = tmp421_enable_channels(data);251 break;252 default:253 ret = -EOPNOTSUPP;254 }255 256 return ret;257}258 259static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,260 u32 attr, int channel)261{262 switch (attr) {263 case hwmon_temp_fault:264 case hwmon_temp_input:265 return 0444;266 case hwmon_temp_label:267 return 0444;268 case hwmon_temp_enable:269 return 0644;270 default:271 return 0;272 }273}274 275static int tmp421_init_client(struct tmp421_data *data)276{277 int config, config_orig;278 struct i2c_client *client = data->client;279 280 /* Set the conversion rate to 2 Hz */281 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);282 283 /* Start conversions (disable shutdown if necessary) */284 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);285 if (config < 0) {286 dev_err(&client->dev,287 "Could not read configuration register (%d)\n", config);288 return config;289 }290 291 config_orig = config;292 config &= ~TMP421_CONFIG_SHUTDOWN;293 294 if (config != config_orig) {295 dev_info(&client->dev, "Enable monitoring chip\n");296 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);297 }298 299 return tmp421_enable_channels(data);300}301 302static int tmp421_detect(struct i2c_client *client,303 struct i2c_board_info *info)304{305 enum chips kind;306 struct i2c_adapter *adapter = client->adapter;307 static const char * const names[] = {308 "TMP421", "TMP422", "TMP423",309 "TMP441", "TMP442"310 };311 int addr = client->addr;312 u8 reg;313 314 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))315 return -ENODEV;316 317 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);318 if (reg != TMP421_MANUFACTURER_ID)319 return -ENODEV;320 321 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);322 if (reg & 0xf8)323 return -ENODEV;324 325 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);326 if (reg & 0x7f)327 return -ENODEV;328 329 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);330 switch (reg) {331 case TMP421_DEVICE_ID:332 kind = tmp421;333 break;334 case TMP422_DEVICE_ID:335 if (addr == 0x2a)336 return -ENODEV;337 kind = tmp422;338 break;339 case TMP423_DEVICE_ID:340 if (addr != 0x4c && addr != 0x4d)341 return -ENODEV;342 kind = tmp423;343 break;344 case TMP441_DEVICE_ID:345 kind = tmp441;346 break;347 case TMP442_DEVICE_ID:348 if (addr != 0x4c && addr != 0x4d)349 return -ENODEV;350 kind = tmp442;351 break;352 default:353 return -ENODEV;354 }355 356 strscpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);357 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",358 names[kind], client->addr);359 360 return 0;361}362 363static int tmp421_probe_child_from_dt(struct i2c_client *client,364 struct device_node *child,365 struct tmp421_data *data)366 367{368 struct device *dev = &client->dev;369 u32 i;370 s32 val;371 int err;372 373 err = of_property_read_u32(child, "reg", &i);374 if (err) {375 dev_err(dev, "missing reg property of %pOFn\n", child);376 return err;377 }378 379 if (i >= data->channels) {380 dev_err(dev, "invalid reg %d of %pOFn\n", i, child);381 return -EINVAL;382 }383 384 of_property_read_string(child, "label", &data->channel[i].label);385 if (data->channel[i].label)386 data->temp_config[i] |= HWMON_T_LABEL;387 388 data->channel[i].enabled = of_device_is_available(child);389 390 err = of_property_read_s32(child, "ti,n-factor", &val);391 if (!err) {392 if (i == 0) {393 dev_err(dev, "n-factor can't be set for internal channel\n");394 return -EINVAL;395 }396 397 if (val > 127 || val < -128) {398 dev_err(dev, "n-factor for channel %d invalid (%d)\n",399 i, val);400 return -EINVAL;401 }402 i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1,403 val);404 }405 406 return 0;407}408 409static int tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)410{411 struct device *dev = &client->dev;412 const struct device_node *np = dev->of_node;413 int err;414 415 for_each_child_of_node_scoped(np, child) {416 if (strcmp(child->name, "channel"))417 continue;418 419 err = tmp421_probe_child_from_dt(client, child, data);420 if (err)421 return err;422 }423 424 return 0;425}426 427static const struct hwmon_ops tmp421_ops = {428 .is_visible = tmp421_is_visible,429 .read = tmp421_read,430 .read_string = tmp421_read_string,431 .write = tmp421_write,432};433 434static int tmp421_probe(struct i2c_client *client)435{436 struct device *dev = &client->dev;437 struct device *hwmon_dev;438 struct tmp421_data *data;439 int i, err;440 441 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);442 if (!data)443 return -ENOMEM;444 445 mutex_init(&data->update_lock);446 data->channels = (unsigned long)i2c_get_match_data(client);447 data->client = client;448 449 for (i = 0; i < data->channels; i++) {450 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;451 data->channel[i].enabled = true;452 }453 454 err = tmp421_probe_from_dt(client, data);455 if (err)456 return err;457 458 err = tmp421_init_client(data);459 if (err)460 return err;461 462 data->chip.ops = &tmp421_ops;463 data->chip.info = data->info;464 465 data->info[0] = &data->temp_info;466 467 data->temp_info.type = hwmon_temp;468 data->temp_info.config = data->temp_config;469 470 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,471 data,472 &data->chip,473 NULL);474 return PTR_ERR_OR_ZERO(hwmon_dev);475}476 477static struct i2c_driver tmp421_driver = {478 .class = I2C_CLASS_HWMON,479 .driver = {480 .name = "tmp421",481 .of_match_table = of_match_ptr(tmp421_of_match),482 },483 .probe = tmp421_probe,484 .id_table = tmp421_id,485 .detect = tmp421_detect,486 .address_list = normal_i2c,487};488 489module_i2c_driver(tmp421_driver);490 491MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");492MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");493MODULE_LICENSE("GPL");494