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