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