1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Texas Instruments TMP102 SMBus temperature sensor driver 3 * 4 * Copyright (C) 2010 Steven King <sfking@fdwdc.com> 5 */ 6 7 #include <linux/delay.h> 8 #include <linux/module.h> 9 #include <linux/init.h> 10 #include <linux/slab.h> 11 #include <linux/i2c.h> 12 #include <linux/hwmon.h> 13 #include <linux/err.h> 14 #include <linux/device.h> 15 #include <linux/jiffies.h> 16 #include <linux/regmap.h> 17 #include <linux/regulator/consumer.h> 18 #include <linux/mod_devicetable.h> 19 #include <linux/property.h> 20 21 #define DRIVER_NAME "tmp102" 22 23 #define TMP102_TEMP_REG 0x00 24 #define TMP102_CONF_REG 0x01 25 /* note: these bit definitions are byte swapped */ 26 #define TMP102_CONF_SD 0x0100 27 #define TMP102_CONF_TM 0x0200 28 #define TMP102_CONF_POL 0x0400 29 #define TMP102_CONF_F0 0x0800 30 #define TMP102_CONF_F1 0x1000 31 #define TMP102_CONF_R0 0x2000 32 #define TMP102_CONF_R1 0x4000 33 #define TMP102_CONF_OS 0x8000 34 #define TMP102_CONF_EM 0x0010 35 #define TMP102_CONF_AL 0x0020 36 #define TMP102_CONF_CR0 0x0040 37 #define TMP102_CONF_CR1 0x0080 38 #define TMP102_TLOW_REG 0x02 39 #define TMP102_THIGH_REG 0x03 40 41 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ 42 TMP102_CONF_POL | TMP102_CONF_F0 | \ 43 TMP102_CONF_F1 | TMP102_CONF_OS | \ 44 TMP102_CONF_EM | TMP102_CONF_AL | \ 45 TMP102_CONF_CR0 | TMP102_CONF_CR1) 46 47 #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ 48 TMP102_CONF_CR0) 49 #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ 50 TMP102_CONF_CR1) 51 52 #define CONVERSION_TIME_MS 35 /* in milli-seconds */ 53 54 #define NUM_SAMPLE_TIMES 4 55 #define DEFAULT_SAMPLE_TIME_MS 250 56 static const unsigned int *sample_times = (const unsigned int []){ 125, 250, 1000, 4000 }; 57 58 struct tmp102 { 59 const char *label; 60 struct regmap *regmap; 61 u16 config_orig; 62 unsigned long ready_time; 63 u16 sample_time; 64 }; 65 66 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 67 static inline int tmp102_reg_to_mC(s16 val) 68 { 69 return ((val & ~0x01) * 1000) / 128; 70 } 71 72 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 73 static inline u16 tmp102_mC_to_reg(int val) 74 { 75 return (val * 128) / 1000; 76 } 77 78 static int tmp102_read_string(struct device *dev, enum hwmon_sensor_types type, 79 u32 attr, int channel, const char **str) 80 { 81 struct tmp102 *tmp102 = dev_get_drvdata(dev); 82 83 *str = tmp102->label; 84 85 return 0; 86 } 87 88 static int tmp102_read_chip(struct device *dev, u32 attr, long *val) 89 { 90 struct tmp102 *tmp102 = dev_get_drvdata(dev); 91 92 switch (attr) { 93 case hwmon_chip_update_interval: 94 *val = tmp102->sample_time; 95 return 0; 96 default: 97 return -EOPNOTSUPP; 98 } 99 } 100 101 static int tmp102_read_temp(struct device *dev, u32 attr, long *val) 102 { 103 struct tmp102 *tmp102 = dev_get_drvdata(dev); 104 unsigned int regval; 105 int err, reg; 106 107 switch (attr) { 108 case hwmon_temp_input: 109 /* Is it too early to return a conversion ? */ 110 if (time_before(jiffies, tmp102->ready_time)) { 111 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); 112 return -EAGAIN; 113 } 114 reg = TMP102_TEMP_REG; 115 break; 116 case hwmon_temp_max_hyst: 117 reg = TMP102_TLOW_REG; 118 break; 119 case hwmon_temp_max: 120 reg = TMP102_THIGH_REG; 121 break; 122 default: 123 return -EOPNOTSUPP; 124 } 125 126 err = regmap_read(tmp102->regmap, reg, ®val); 127 if (err < 0) 128 return err; 129 130 *val = tmp102_reg_to_mC(regval); 131 132 return 0; 133 } 134 135 static int tmp102_read(struct device *dev, enum hwmon_sensor_types type, 136 u32 attr, int channel, long *val) 137 { 138 switch (type) { 139 case hwmon_chip: 140 return tmp102_read_chip(dev, attr, val); 141 case hwmon_temp: 142 return tmp102_read_temp(dev, attr, val); 143 default: 144 return -EOPNOTSUPP; 145 } 146 } 147 148 static int tmp102_update_interval(struct device *dev, long val) 149 { 150 struct tmp102 *tmp102 = dev_get_drvdata(dev); 151 u8 index; 152 s32 err; 153 154 index = find_closest(val, sample_times, NUM_SAMPLE_TIMES); 155 156 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 157 (TMP102_CONF_CR1 | TMP102_CONF_CR0), (3 - index) << 6); 158 if (err < 0) 159 return err; 160 tmp102->sample_time = sample_times[index]; 161 162 return 0; 163 } 164 165 static int tmp102_write_chip(struct device *dev, u32 attr, long val) 166 { 167 switch (attr) { 168 case hwmon_chip_update_interval: 169 return tmp102_update_interval(dev, val); 170 default: 171 return -EOPNOTSUPP; 172 } 173 return 0; 174 } 175 176 static int tmp102_write_temp(struct device *dev, u32 attr, long val) 177 { 178 struct tmp102 *tmp102 = dev_get_drvdata(dev); 179 int reg; 180 181 switch (attr) { 182 case hwmon_temp_max_hyst: 183 reg = TMP102_TLOW_REG; 184 break; 185 case hwmon_temp_max: 186 reg = TMP102_THIGH_REG; 187 break; 188 default: 189 return -EOPNOTSUPP; 190 } 191 192 val = clamp_val(val, -256000, 255000); 193 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(val)); 194 } 195 196 static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, 197 u32 attr, int channel, long val) 198 { 199 switch (type) { 200 case hwmon_chip: 201 return tmp102_write_chip(dev, attr, val); 202 case hwmon_temp: 203 return tmp102_write_temp(dev, attr, val); 204 default: 205 return -EOPNOTSUPP; 206 } 207 return 0; 208 } 209 210 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, 211 u32 attr, int channel) 212 { 213 const struct tmp102 *tmp102 = data; 214 215 switch (type) { 216 case hwmon_chip: 217 switch (attr) { 218 case hwmon_chip_update_interval: 219 return 0644; 220 default: 221 break; 222 } 223 break; 224 case hwmon_temp: 225 switch (attr) { 226 case hwmon_temp_input: 227 return 0444; 228 case hwmon_temp_label: 229 if (tmp102->label) 230 return 0444; 231 return 0; 232 case hwmon_temp_max_hyst: 233 case hwmon_temp_max: 234 return 0644; 235 default: 236 break; 237 } 238 break; 239 default: 240 break; 241 } 242 return 0; 243 } 244 245 static const struct hwmon_channel_info * const tmp102_info[] = { 246 HWMON_CHANNEL_INFO(chip, 247 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL), 248 HWMON_CHANNEL_INFO(temp, 249 HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_MAX | HWMON_T_MAX_HYST), 250 NULL 251 }; 252 253 static const struct hwmon_ops tmp102_hwmon_ops = { 254 .is_visible = tmp102_is_visible, 255 .read_string = tmp102_read_string, 256 .read = tmp102_read, 257 .write = tmp102_write, 258 }; 259 260 static const struct hwmon_chip_info tmp102_chip_info = { 261 .ops = &tmp102_hwmon_ops, 262 .info = tmp102_info, 263 }; 264 265 static void tmp102_restore_config(void *data) 266 { 267 struct tmp102 *tmp102 = data; 268 269 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); 270 } 271 272 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) 273 { 274 return reg != TMP102_TEMP_REG; 275 } 276 277 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) 278 { 279 return reg == TMP102_TEMP_REG; 280 } 281 282 static const struct regmap_config tmp102_regmap_config = { 283 .reg_bits = 8, 284 .val_bits = 16, 285 .max_register = TMP102_THIGH_REG, 286 .writeable_reg = tmp102_is_writeable_reg, 287 .volatile_reg = tmp102_is_volatile_reg, 288 .val_format_endian = REGMAP_ENDIAN_BIG, 289 .cache_type = REGCACHE_MAPLE, 290 .use_single_read = true, 291 .use_single_write = true, 292 }; 293 294 static int tmp102_probe(struct i2c_client *client) 295 { 296 struct device *dev = &client->dev; 297 struct device *hwmon_dev; 298 struct tmp102 *tmp102; 299 unsigned int regval; 300 int err; 301 302 if (!i2c_check_functionality(client->adapter, 303 I2C_FUNC_SMBUS_WORD_DATA)) { 304 dev_err(dev, 305 "adapter doesn't support SMBus word transactions\n"); 306 return -ENODEV; 307 } 308 309 err = devm_regulator_get_enable_optional(dev, "vcc"); 310 if (err < 0 && err != -ENODEV) 311 return dev_err_probe(dev, err, "Failed to enable regulator\n"); 312 313 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 314 if (!tmp102) 315 return -ENOMEM; 316 317 device_property_read_string(dev, "label", &tmp102->label); 318 319 i2c_set_clientdata(client, tmp102); 320 321 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); 322 if (IS_ERR(tmp102->regmap)) 323 return PTR_ERR(tmp102->regmap); 324 325 tmp102->sample_time = DEFAULT_SAMPLE_TIME_MS; 326 327 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); 328 if (err < 0) { 329 dev_err(dev, "error reading config register\n"); 330 return err; 331 } 332 333 if ((regval & ~TMP102_CONFREG_MASK) != 334 (TMP102_CONF_R0 | TMP102_CONF_R1)) { 335 dev_err(dev, "unexpected config register value\n"); 336 return -ENODEV; 337 } 338 339 tmp102->config_orig = regval; 340 341 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); 342 if (err) 343 return err; 344 345 regval &= ~TMP102_CONFIG_CLEAR; 346 regval |= TMP102_CONFIG_SET; 347 348 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); 349 if (err < 0) { 350 dev_err(dev, "error writing config register\n"); 351 return err; 352 } 353 354 /* 355 * Mark that we are not ready with data until the first 356 * conversion is complete 357 */ 358 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 359 360 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 361 tmp102, 362 &tmp102_chip_info, 363 NULL); 364 if (IS_ERR(hwmon_dev)) { 365 dev_dbg(dev, "unable to register hwmon device\n"); 366 return PTR_ERR(hwmon_dev); 367 } 368 dev_info(dev, "initialized\n"); 369 370 return 0; 371 } 372 373 static int tmp102_suspend(struct device *dev) 374 { 375 struct i2c_client *client = to_i2c_client(dev); 376 struct tmp102 *tmp102 = i2c_get_clientdata(client); 377 378 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 379 TMP102_CONF_SD, TMP102_CONF_SD); 380 } 381 382 static int tmp102_resume(struct device *dev) 383 { 384 struct i2c_client *client = to_i2c_client(dev); 385 struct tmp102 *tmp102 = i2c_get_clientdata(client); 386 int err; 387 388 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 389 TMP102_CONF_SD, 0); 390 391 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 392 393 return err; 394 } 395 396 static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 397 398 static const struct i2c_device_id tmp102_id[] = { 399 { .name = "tmp102" }, 400 { } 401 }; 402 MODULE_DEVICE_TABLE(i2c, tmp102_id); 403 404 static const struct of_device_id tmp102_of_match[] = { 405 { .compatible = "ti,tmp102" }, 406 { }, 407 }; 408 MODULE_DEVICE_TABLE(of, tmp102_of_match); 409 410 static struct i2c_driver tmp102_driver = { 411 .driver.name = DRIVER_NAME, 412 .driver.of_match_table = tmp102_of_match, 413 .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops), 414 .probe = tmp102_probe, 415 .id_table = tmp102_id, 416 }; 417 418 module_i2c_driver(tmp102_driver); 419 420 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 421 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 422 MODULE_LICENSE("GPL"); 423