1 /* Texas Instruments TMP102 SMBus temperature sensor driver 2 * 3 * Copyright (C) 2010 Steven King <sfking@fdwdc.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/delay.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/slab.h> 20 #include <linux/i2c.h> 21 #include <linux/hwmon.h> 22 #include <linux/hwmon-sysfs.h> 23 #include <linux/err.h> 24 #include <linux/mutex.h> 25 #include <linux/device.h> 26 #include <linux/jiffies.h> 27 #include <linux/regmap.h> 28 #include <linux/of.h> 29 30 #define DRIVER_NAME "tmp102" 31 32 #define TMP102_TEMP_REG 0x00 33 #define TMP102_CONF_REG 0x01 34 /* note: these bit definitions are byte swapped */ 35 #define TMP102_CONF_SD 0x0100 36 #define TMP102_CONF_TM 0x0200 37 #define TMP102_CONF_POL 0x0400 38 #define TMP102_CONF_F0 0x0800 39 #define TMP102_CONF_F1 0x1000 40 #define TMP102_CONF_R0 0x2000 41 #define TMP102_CONF_R1 0x4000 42 #define TMP102_CONF_OS 0x8000 43 #define TMP102_CONF_EM 0x0010 44 #define TMP102_CONF_AL 0x0020 45 #define TMP102_CONF_CR0 0x0040 46 #define TMP102_CONF_CR1 0x0080 47 #define TMP102_TLOW_REG 0x02 48 #define TMP102_THIGH_REG 0x03 49 50 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ 51 TMP102_CONF_POL | TMP102_CONF_F0 | \ 52 TMP102_CONF_F1 | TMP102_CONF_OS | \ 53 TMP102_CONF_EM | TMP102_CONF_AL | \ 54 TMP102_CONF_CR0 | TMP102_CONF_CR1) 55 56 #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ 57 TMP102_CONF_CR0) 58 #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ 59 TMP102_CONF_CR1) 60 61 #define CONVERSION_TIME_MS 35 /* in milli-seconds */ 62 63 struct tmp102 { 64 struct regmap *regmap; 65 u16 config_orig; 66 unsigned long ready_time; 67 }; 68 69 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 70 static inline int tmp102_reg_to_mC(s16 val) 71 { 72 return ((val & ~0x01) * 1000) / 128; 73 } 74 75 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 76 static inline u16 tmp102_mC_to_reg(int val) 77 { 78 return (val * 128) / 1000; 79 } 80 81 static int tmp102_read(struct device *dev, enum hwmon_sensor_types type, 82 u32 attr, int channel, long *temp) 83 { 84 struct tmp102 *tmp102 = dev_get_drvdata(dev); 85 unsigned int regval; 86 int err, reg; 87 88 switch (attr) { 89 case hwmon_temp_input: 90 /* Is it too early to return a conversion ? */ 91 if (time_before(jiffies, tmp102->ready_time)) { 92 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); 93 return -EAGAIN; 94 } 95 reg = TMP102_TEMP_REG; 96 break; 97 case hwmon_temp_max_hyst: 98 reg = TMP102_TLOW_REG; 99 break; 100 case hwmon_temp_max: 101 reg = TMP102_THIGH_REG; 102 break; 103 default: 104 return -EOPNOTSUPP; 105 } 106 107 err = regmap_read(tmp102->regmap, reg, ®val); 108 if (err < 0) 109 return err; 110 *temp = tmp102_reg_to_mC(regval); 111 112 return 0; 113 } 114 115 static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, 116 u32 attr, int channel, long temp) 117 { 118 struct tmp102 *tmp102 = dev_get_drvdata(dev); 119 int reg; 120 121 switch (attr) { 122 case hwmon_temp_max_hyst: 123 reg = TMP102_TLOW_REG; 124 break; 125 case hwmon_temp_max: 126 reg = TMP102_THIGH_REG; 127 break; 128 default: 129 return -EOPNOTSUPP; 130 } 131 132 temp = clamp_val(temp, -256000, 255000); 133 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp)); 134 } 135 136 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, 137 u32 attr, int channel) 138 { 139 if (type != hwmon_temp) 140 return 0; 141 142 switch (attr) { 143 case hwmon_temp_input: 144 return S_IRUGO; 145 case hwmon_temp_max_hyst: 146 case hwmon_temp_max: 147 return S_IRUGO | S_IWUSR; 148 default: 149 return 0; 150 } 151 } 152 153 static u32 tmp102_chip_config[] = { 154 HWMON_C_REGISTER_TZ, 155 0 156 }; 157 158 static const struct hwmon_channel_info tmp102_chip = { 159 .type = hwmon_chip, 160 .config = tmp102_chip_config, 161 }; 162 163 static u32 tmp102_temp_config[] = { 164 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, 165 0 166 }; 167 168 static const struct hwmon_channel_info tmp102_temp = { 169 .type = hwmon_temp, 170 .config = tmp102_temp_config, 171 }; 172 173 static const struct hwmon_channel_info *tmp102_info[] = { 174 &tmp102_chip, 175 &tmp102_temp, 176 NULL 177 }; 178 179 static const struct hwmon_ops tmp102_hwmon_ops = { 180 .is_visible = tmp102_is_visible, 181 .read = tmp102_read, 182 .write = tmp102_write, 183 }; 184 185 static const struct hwmon_chip_info tmp102_chip_info = { 186 .ops = &tmp102_hwmon_ops, 187 .info = tmp102_info, 188 }; 189 190 static void tmp102_restore_config(void *data) 191 { 192 struct tmp102 *tmp102 = data; 193 194 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); 195 } 196 197 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) 198 { 199 return reg != TMP102_TEMP_REG; 200 } 201 202 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) 203 { 204 return reg == TMP102_TEMP_REG; 205 } 206 207 static const struct regmap_config tmp102_regmap_config = { 208 .reg_bits = 8, 209 .val_bits = 16, 210 .max_register = TMP102_THIGH_REG, 211 .writeable_reg = tmp102_is_writeable_reg, 212 .volatile_reg = tmp102_is_volatile_reg, 213 .val_format_endian = REGMAP_ENDIAN_BIG, 214 .cache_type = REGCACHE_RBTREE, 215 .use_single_rw = true, 216 }; 217 218 static int tmp102_probe(struct i2c_client *client, 219 const struct i2c_device_id *id) 220 { 221 struct device *dev = &client->dev; 222 struct device *hwmon_dev; 223 struct tmp102 *tmp102; 224 unsigned int regval; 225 int err; 226 227 if (!i2c_check_functionality(client->adapter, 228 I2C_FUNC_SMBUS_WORD_DATA)) { 229 dev_err(dev, 230 "adapter doesn't support SMBus word transactions\n"); 231 return -ENODEV; 232 } 233 234 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 235 if (!tmp102) 236 return -ENOMEM; 237 238 i2c_set_clientdata(client, tmp102); 239 240 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); 241 if (IS_ERR(tmp102->regmap)) 242 return PTR_ERR(tmp102->regmap); 243 244 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); 245 if (err < 0) { 246 dev_err(dev, "error reading config register\n"); 247 return err; 248 } 249 250 if ((regval & ~TMP102_CONFREG_MASK) != 251 (TMP102_CONF_R0 | TMP102_CONF_R1)) { 252 dev_err(dev, "unexpected config register value\n"); 253 return -ENODEV; 254 } 255 256 tmp102->config_orig = regval; 257 258 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); 259 if (err) 260 return err; 261 262 regval &= ~TMP102_CONFIG_CLEAR; 263 regval |= TMP102_CONFIG_SET; 264 265 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); 266 if (err < 0) { 267 dev_err(dev, "error writing config register\n"); 268 return err; 269 } 270 271 tmp102->ready_time = jiffies; 272 if (tmp102->config_orig & TMP102_CONF_SD) { 273 /* 274 * Mark that we are not ready with data until the first 275 * conversion is complete 276 */ 277 tmp102->ready_time += msecs_to_jiffies(CONVERSION_TIME_MS); 278 } 279 280 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 281 tmp102, 282 &tmp102_chip_info, 283 NULL); 284 if (IS_ERR(hwmon_dev)) { 285 dev_dbg(dev, "unable to register hwmon device\n"); 286 return PTR_ERR(hwmon_dev); 287 } 288 dev_info(dev, "initialized\n"); 289 290 return 0; 291 } 292 293 #ifdef CONFIG_PM_SLEEP 294 static int tmp102_suspend(struct device *dev) 295 { 296 struct i2c_client *client = to_i2c_client(dev); 297 struct tmp102 *tmp102 = i2c_get_clientdata(client); 298 299 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 300 TMP102_CONF_SD, TMP102_CONF_SD); 301 } 302 303 static int tmp102_resume(struct device *dev) 304 { 305 struct i2c_client *client = to_i2c_client(dev); 306 struct tmp102 *tmp102 = i2c_get_clientdata(client); 307 int err; 308 309 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 310 TMP102_CONF_SD, 0); 311 312 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 313 314 return err; 315 } 316 #endif /* CONFIG_PM */ 317 318 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 319 320 static const struct i2c_device_id tmp102_id[] = { 321 { "tmp102", 0 }, 322 { } 323 }; 324 MODULE_DEVICE_TABLE(i2c, tmp102_id); 325 326 static struct i2c_driver tmp102_driver = { 327 .driver.name = DRIVER_NAME, 328 .driver.pm = &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