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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Texas Instruments TMP108 SMBus temperature sensor driver3 *4 * Copyright (C) 2016 John Muir <john@jmuir.com>5 */6 7#include <linux/delay.h>8#include <linux/device.h>9#include <linux/err.h>10#include <linux/hwmon.h>11#include <linux/hwmon-sysfs.h>12#include <linux/module.h>13#include <linux/mutex.h>14#include <linux/of.h>15#include <linux/i2c.h>16#include <linux/init.h>17#include <linux/jiffies.h>18#include <linux/regmap.h>19#include <linux/slab.h>20 21#define DRIVER_NAME "tmp108"22 23#define TMP108_REG_TEMP 0x0024#define TMP108_REG_CONF 0x0125#define TMP108_REG_TLOW 0x0226#define TMP108_REG_THIGH 0x0327 28#define TMP108_TEMP_MIN_MC -50000 /* Minimum millicelcius. */29#define TMP108_TEMP_MAX_MC 127937 /* Maximum millicelcius. */30 31/* Configuration register bits.32 * Note: these bit definitions are byte swapped.33 */34#define TMP108_CONF_M0 0x0100 /* Sensor mode. */35#define TMP108_CONF_M1 0x020036#define TMP108_CONF_TM 0x0400 /* Thermostat mode. */37#define TMP108_CONF_FL 0x0800 /* Watchdog flag - TLOW */38#define TMP108_CONF_FH 0x1000 /* Watchdog flag - THIGH */39#define TMP108_CONF_CR0 0x2000 /* Conversion rate. */40#define TMP108_CONF_CR1 0x400041#define TMP108_CONF_ID 0x800042#define TMP108_CONF_HYS0 0x0010 /* Hysteresis. */43#define TMP108_CONF_HYS1 0x002044#define TMP108_CONF_POL 0x0080 /* Polarity of alert. */45 46/* Defaults set by the hardware upon reset. */47#define TMP108_CONF_DEFAULTS (TMP108_CONF_CR0 | TMP108_CONF_TM |\48 TMP108_CONF_HYS0 | TMP108_CONF_M1)49/* These bits are read-only. */50#define TMP108_CONF_READ_ONLY (TMP108_CONF_FL | TMP108_CONF_FH |\51 TMP108_CONF_ID)52 53#define TMP108_CONF_MODE_MASK (TMP108_CONF_M0|TMP108_CONF_M1)54#define TMP108_MODE_SHUTDOWN 0x000055#define TMP108_MODE_ONE_SHOT TMP108_CONF_M056#define TMP108_MODE_CONTINUOUS TMP108_CONF_M1 /* Default */57 /* When M1 is set, M0 is ignored. */58 59#define TMP108_CONF_CONVRATE_MASK (TMP108_CONF_CR0|TMP108_CONF_CR1)60#define TMP108_CONVRATE_0P25HZ 0x000061#define TMP108_CONVRATE_1HZ TMP108_CONF_CR0 /* Default */62#define TMP108_CONVRATE_4HZ TMP108_CONF_CR163#define TMP108_CONVRATE_16HZ (TMP108_CONF_CR0|TMP108_CONF_CR1)64 65#define TMP108_CONF_HYSTERESIS_MASK (TMP108_CONF_HYS0|TMP108_CONF_HYS1)66#define TMP108_HYSTERESIS_0C 0x000067#define TMP108_HYSTERESIS_1C TMP108_CONF_HYS0 /* Default */68#define TMP108_HYSTERESIS_2C TMP108_CONF_HYS169#define TMP108_HYSTERESIS_4C (TMP108_CONF_HYS0|TMP108_CONF_HYS1)70 71#define TMP108_CONVERSION_TIME_MS 30 /* in milli-seconds */72 73struct tmp108 {74 struct regmap *regmap;75 u16 orig_config;76 unsigned long ready_time;77};78 79/* convert 12-bit TMP108 register value to milliCelsius */80static inline int tmp108_temp_reg_to_mC(s16 val)81{82 return (val & ~0x0f) * 1000 / 256;83}84 85/* convert milliCelsius to left adjusted 12-bit TMP108 register value */86static inline u16 tmp108_mC_to_temp_reg(int val)87{88 return (val * 256) / 1000;89}90 91static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,92 u32 attr, int channel, long *temp)93{94 struct tmp108 *tmp108 = dev_get_drvdata(dev);95 unsigned int regval;96 int err, hyst;97 98 if (type == hwmon_chip) {99 if (attr == hwmon_chip_update_interval) {100 err = regmap_read(tmp108->regmap, TMP108_REG_CONF,101 ®val);102 if (err < 0)103 return err;104 switch (regval & TMP108_CONF_CONVRATE_MASK) {105 case TMP108_CONVRATE_0P25HZ:106 default:107 *temp = 4000;108 break;109 case TMP108_CONVRATE_1HZ:110 *temp = 1000;111 break;112 case TMP108_CONVRATE_4HZ:113 *temp = 250;114 break;115 case TMP108_CONVRATE_16HZ:116 *temp = 63;117 break;118 }119 return 0;120 }121 return -EOPNOTSUPP;122 }123 124 switch (attr) {125 case hwmon_temp_input:126 /* Is it too early to return a conversion ? */127 if (time_before(jiffies, tmp108->ready_time)) {128 dev_dbg(dev, "%s: Conversion not ready yet..\n",129 __func__);130 return -EAGAIN;131 }132 err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, ®val);133 if (err < 0)134 return err;135 *temp = tmp108_temp_reg_to_mC(regval);136 break;137 case hwmon_temp_min:138 case hwmon_temp_max:139 err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?140 TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);141 if (err < 0)142 return err;143 *temp = tmp108_temp_reg_to_mC(regval);144 break;145 case hwmon_temp_min_alarm:146 case hwmon_temp_max_alarm:147 err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);148 if (err < 0)149 return err;150 *temp = !!(regval & (attr == hwmon_temp_min_alarm ?151 TMP108_CONF_FL : TMP108_CONF_FH));152 break;153 case hwmon_temp_min_hyst:154 case hwmon_temp_max_hyst:155 err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);156 if (err < 0)157 return err;158 switch (regval & TMP108_CONF_HYSTERESIS_MASK) {159 case TMP108_HYSTERESIS_0C:160 default:161 hyst = 0;162 break;163 case TMP108_HYSTERESIS_1C:164 hyst = 1000;165 break;166 case TMP108_HYSTERESIS_2C:167 hyst = 2000;168 break;169 case TMP108_HYSTERESIS_4C:170 hyst = 4000;171 break;172 }173 err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?174 TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);175 if (err < 0)176 return err;177 *temp = tmp108_temp_reg_to_mC(regval);178 if (attr == hwmon_temp_min_hyst)179 *temp += hyst;180 else181 *temp -= hyst;182 break;183 default:184 return -EOPNOTSUPP;185 }186 187 return 0;188}189 190static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,191 u32 attr, int channel, long temp)192{193 struct tmp108 *tmp108 = dev_get_drvdata(dev);194 u32 regval, mask;195 int err;196 197 if (type == hwmon_chip) {198 if (attr == hwmon_chip_update_interval) {199 if (temp < 156)200 mask = TMP108_CONVRATE_16HZ;201 else if (temp < 625)202 mask = TMP108_CONVRATE_4HZ;203 else if (temp < 2500)204 mask = TMP108_CONVRATE_1HZ;205 else206 mask = TMP108_CONVRATE_0P25HZ;207 return regmap_update_bits(tmp108->regmap,208 TMP108_REG_CONF,209 TMP108_CONF_CONVRATE_MASK,210 mask);211 }212 return -EOPNOTSUPP;213 }214 215 switch (attr) {216 case hwmon_temp_min:217 case hwmon_temp_max:218 temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);219 return regmap_write(tmp108->regmap,220 attr == hwmon_temp_min ?221 TMP108_REG_TLOW : TMP108_REG_THIGH,222 tmp108_mC_to_temp_reg(temp));223 case hwmon_temp_min_hyst:224 case hwmon_temp_max_hyst:225 temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);226 err = regmap_read(tmp108->regmap,227 attr == hwmon_temp_min_hyst ?228 TMP108_REG_TLOW : TMP108_REG_THIGH,229 ®val);230 if (err < 0)231 return err;232 if (attr == hwmon_temp_min_hyst)233 temp -= tmp108_temp_reg_to_mC(regval);234 else235 temp = tmp108_temp_reg_to_mC(regval) - temp;236 if (temp < 500)237 mask = TMP108_HYSTERESIS_0C;238 else if (temp < 1500)239 mask = TMP108_HYSTERESIS_1C;240 else if (temp < 3000)241 mask = TMP108_HYSTERESIS_2C;242 else243 mask = TMP108_HYSTERESIS_4C;244 return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,245 TMP108_CONF_HYSTERESIS_MASK, mask);246 default:247 return -EOPNOTSUPP;248 }249}250 251static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,252 u32 attr, int channel)253{254 if (type == hwmon_chip && attr == hwmon_chip_update_interval)255 return 0644;256 257 if (type != hwmon_temp)258 return 0;259 260 switch (attr) {261 case hwmon_temp_input:262 case hwmon_temp_min_alarm:263 case hwmon_temp_max_alarm:264 return 0444;265 case hwmon_temp_min:266 case hwmon_temp_max:267 case hwmon_temp_min_hyst:268 case hwmon_temp_max_hyst:269 return 0644;270 default:271 return 0;272 }273}274 275static const struct hwmon_channel_info * const tmp108_info[] = {276 HWMON_CHANNEL_INFO(chip,277 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),278 HWMON_CHANNEL_INFO(temp,279 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |280 HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |281 HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),282 NULL283};284 285static const struct hwmon_ops tmp108_hwmon_ops = {286 .is_visible = tmp108_is_visible,287 .read = tmp108_read,288 .write = tmp108_write,289};290 291static const struct hwmon_chip_info tmp108_chip_info = {292 .ops = &tmp108_hwmon_ops,293 .info = tmp108_info,294};295 296static void tmp108_restore_config(void *data)297{298 struct tmp108 *tmp108 = data;299 300 regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);301}302 303static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)304{305 return reg != TMP108_REG_TEMP;306}307 308static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)309{310 /* Configuration register must be volatile to enable FL and FH. */311 return reg == TMP108_REG_TEMP || reg == TMP108_REG_CONF;312}313 314static const struct regmap_config tmp108_regmap_config = {315 .reg_bits = 8,316 .val_bits = 16,317 .max_register = TMP108_REG_THIGH,318 .writeable_reg = tmp108_is_writeable_reg,319 .volatile_reg = tmp108_is_volatile_reg,320 .val_format_endian = REGMAP_ENDIAN_BIG,321 .cache_type = REGCACHE_MAPLE,322 .use_single_read = true,323 .use_single_write = true,324};325 326static int tmp108_probe(struct i2c_client *client)327{328 struct device *dev = &client->dev;329 struct device *hwmon_dev;330 struct tmp108 *tmp108;331 int err;332 u32 config;333 334 if (!i2c_check_functionality(client->adapter,335 I2C_FUNC_SMBUS_WORD_DATA)) {336 dev_err(dev,337 "adapter doesn't support SMBus word transactions\n");338 return -ENODEV;339 }340 341 tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);342 if (!tmp108)343 return -ENOMEM;344 345 dev_set_drvdata(dev, tmp108);346 347 tmp108->regmap = devm_regmap_init_i2c(client, &tmp108_regmap_config);348 if (IS_ERR(tmp108->regmap)) {349 err = PTR_ERR(tmp108->regmap);350 dev_err(dev, "regmap init failed: %d", err);351 return err;352 }353 354 err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);355 if (err < 0) {356 dev_err(dev, "error reading config register: %d", err);357 return err;358 }359 tmp108->orig_config = config;360 361 /* Only continuous mode is supported. */362 config &= ~TMP108_CONF_MODE_MASK;363 config |= TMP108_MODE_CONTINUOUS;364 365 /* Only comparator mode is supported. */366 config &= ~TMP108_CONF_TM;367 368 err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);369 if (err < 0) {370 dev_err(dev, "error writing config register: %d", err);371 return err;372 }373 374 tmp108->ready_time = jiffies;375 if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==376 TMP108_MODE_SHUTDOWN)377 tmp108->ready_time +=378 msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);379 380 err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);381 if (err) {382 dev_err(dev, "add action or reset failed: %d", err);383 return err;384 }385 386 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,387 tmp108,388 &tmp108_chip_info,389 NULL);390 return PTR_ERR_OR_ZERO(hwmon_dev);391}392 393static int tmp108_suspend(struct device *dev)394{395 struct tmp108 *tmp108 = dev_get_drvdata(dev);396 397 return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,398 TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);399}400 401static int tmp108_resume(struct device *dev)402{403 struct tmp108 *tmp108 = dev_get_drvdata(dev);404 int err;405 406 err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,407 TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);408 tmp108->ready_time = jiffies +409 msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);410 return err;411}412 413static DEFINE_SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);414 415static const struct i2c_device_id tmp108_i2c_ids[] = {416 { "tmp108" },417 { }418};419MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);420 421#ifdef CONFIG_OF422static const struct of_device_id tmp108_of_ids[] = {423 { .compatible = "ti,tmp108", },424 {}425};426MODULE_DEVICE_TABLE(of, tmp108_of_ids);427#endif428 429static struct i2c_driver tmp108_driver = {430 .driver = {431 .name = DRIVER_NAME,432 .pm = pm_sleep_ptr(&tmp108_dev_pm_ops),433 .of_match_table = of_match_ptr(tmp108_of_ids),434 },435 .probe = tmp108_probe,436 .id_table = tmp108_i2c_ids,437};438 439module_i2c_driver(tmp108_driver);440 441MODULE_AUTHOR("John Muir <john@jmuir.com>");442MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");443MODULE_LICENSE("GPL");444