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/of.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 struct tmp102 { 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(struct device *dev, enum hwmon_sensor_types type, 73 u32 attr, int channel, long *temp) 74 { 75 struct tmp102 *tmp102 = dev_get_drvdata(dev); 76 unsigned int regval; 77 int err, reg; 78 79 switch (attr) { 80 case hwmon_temp_input: 81 /* Is it too early to return a conversion ? */ 82 if (time_before(jiffies, tmp102->ready_time)) { 83 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); 84 return -EAGAIN; 85 } 86 reg = TMP102_TEMP_REG; 87 break; 88 case hwmon_temp_max_hyst: 89 reg = TMP102_TLOW_REG; 90 break; 91 case hwmon_temp_max: 92 reg = TMP102_THIGH_REG; 93 break; 94 default: 95 return -EOPNOTSUPP; 96 } 97 98 err = regmap_read(tmp102->regmap, reg, ®val); 99 if (err < 0) 100 return err; 101 *temp = tmp102_reg_to_mC(regval); 102 103 return 0; 104 } 105 106 static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, 107 u32 attr, int channel, long temp) 108 { 109 struct tmp102 *tmp102 = dev_get_drvdata(dev); 110 int reg; 111 112 switch (attr) { 113 case hwmon_temp_max_hyst: 114 reg = TMP102_TLOW_REG; 115 break; 116 case hwmon_temp_max: 117 reg = TMP102_THIGH_REG; 118 break; 119 default: 120 return -EOPNOTSUPP; 121 } 122 123 temp = clamp_val(temp, -256000, 255000); 124 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp)); 125 } 126 127 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, 128 u32 attr, int channel) 129 { 130 if (type != hwmon_temp) 131 return 0; 132 133 switch (attr) { 134 case hwmon_temp_input: 135 return 0444; 136 case hwmon_temp_max_hyst: 137 case hwmon_temp_max: 138 return 0644; 139 default: 140 return 0; 141 } 142 } 143 144 static const struct hwmon_channel_info * const tmp102_info[] = { 145 HWMON_CHANNEL_INFO(chip, 146 HWMON_C_REGISTER_TZ), 147 HWMON_CHANNEL_INFO(temp, 148 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST), 149 NULL 150 }; 151 152 static const struct hwmon_ops tmp102_hwmon_ops = { 153 .is_visible = tmp102_is_visible, 154 .read = tmp102_read, 155 .write = tmp102_write, 156 }; 157 158 static const struct hwmon_chip_info tmp102_chip_info = { 159 .ops = &tmp102_hwmon_ops, 160 .info = tmp102_info, 161 }; 162 163 static void tmp102_restore_config(void *data) 164 { 165 struct tmp102 *tmp102 = data; 166 167 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); 168 } 169 170 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) 171 { 172 return reg != TMP102_TEMP_REG; 173 } 174 175 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) 176 { 177 return reg == TMP102_TEMP_REG; 178 } 179 180 static const struct regmap_config tmp102_regmap_config = { 181 .reg_bits = 8, 182 .val_bits = 16, 183 .max_register = TMP102_THIGH_REG, 184 .writeable_reg = tmp102_is_writeable_reg, 185 .volatile_reg = tmp102_is_volatile_reg, 186 .val_format_endian = REGMAP_ENDIAN_BIG, 187 .cache_type = REGCACHE_MAPLE, 188 .use_single_read = true, 189 .use_single_write = true, 190 }; 191 192 static int tmp102_probe(struct i2c_client *client) 193 { 194 struct device *dev = &client->dev; 195 struct device *hwmon_dev; 196 struct tmp102 *tmp102; 197 unsigned int regval; 198 int err; 199 200 if (!i2c_check_functionality(client->adapter, 201 I2C_FUNC_SMBUS_WORD_DATA)) { 202 dev_err(dev, 203 "adapter doesn't support SMBus word transactions\n"); 204 return -ENODEV; 205 } 206 207 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 208 if (!tmp102) 209 return -ENOMEM; 210 211 i2c_set_clientdata(client, tmp102); 212 213 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); 214 if (IS_ERR(tmp102->regmap)) 215 return PTR_ERR(tmp102->regmap); 216 217 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); 218 if (err < 0) { 219 dev_err(dev, "error reading config register\n"); 220 return err; 221 } 222 223 if ((regval & ~TMP102_CONFREG_MASK) != 224 (TMP102_CONF_R0 | TMP102_CONF_R1)) { 225 dev_err(dev, "unexpected config register value\n"); 226 return -ENODEV; 227 } 228 229 tmp102->config_orig = regval; 230 231 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); 232 if (err) 233 return err; 234 235 regval &= ~TMP102_CONFIG_CLEAR; 236 regval |= TMP102_CONFIG_SET; 237 238 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); 239 if (err < 0) { 240 dev_err(dev, "error writing config register\n"); 241 return err; 242 } 243 244 /* 245 * Mark that we are not ready with data until the first 246 * conversion is complete 247 */ 248 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 249 250 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 251 tmp102, 252 &tmp102_chip_info, 253 NULL); 254 if (IS_ERR(hwmon_dev)) { 255 dev_dbg(dev, "unable to register hwmon device\n"); 256 return PTR_ERR(hwmon_dev); 257 } 258 dev_info(dev, "initialized\n"); 259 260 return 0; 261 } 262 263 static int tmp102_suspend(struct device *dev) 264 { 265 struct i2c_client *client = to_i2c_client(dev); 266 struct tmp102 *tmp102 = i2c_get_clientdata(client); 267 268 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 269 TMP102_CONF_SD, TMP102_CONF_SD); 270 } 271 272 static int tmp102_resume(struct device *dev) 273 { 274 struct i2c_client *client = to_i2c_client(dev); 275 struct tmp102 *tmp102 = i2c_get_clientdata(client); 276 int err; 277 278 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 279 TMP102_CONF_SD, 0); 280 281 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 282 283 return err; 284 } 285 286 static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 287 288 static const struct i2c_device_id tmp102_id[] = { 289 { "tmp102" }, 290 { } 291 }; 292 MODULE_DEVICE_TABLE(i2c, tmp102_id); 293 294 static const struct of_device_id __maybe_unused tmp102_of_match[] = { 295 { .compatible = "ti,tmp102" }, 296 { }, 297 }; 298 MODULE_DEVICE_TABLE(of, tmp102_of_match); 299 300 static struct i2c_driver tmp102_driver = { 301 .driver.name = DRIVER_NAME, 302 .driver.of_match_table = of_match_ptr(tmp102_of_match), 303 .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops), 304 .probe = tmp102_probe, 305 .id_table = tmp102_id, 306 }; 307 308 module_i2c_driver(tmp102_driver); 309 310 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 311 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 312 MODULE_LICENSE("GPL"); 313