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 0444; 145 case hwmon_temp_max_hyst: 146 case hwmon_temp_max: 147 return 0644; 148 default: 149 return 0; 150 } 151 } 152 153 static const struct hwmon_channel_info *tmp102_info[] = { 154 HWMON_CHANNEL_INFO(chip, 155 HWMON_C_REGISTER_TZ), 156 HWMON_CHANNEL_INFO(temp, 157 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST), 158 NULL 159 }; 160 161 static const struct hwmon_ops tmp102_hwmon_ops = { 162 .is_visible = tmp102_is_visible, 163 .read = tmp102_read, 164 .write = tmp102_write, 165 }; 166 167 static const struct hwmon_chip_info tmp102_chip_info = { 168 .ops = &tmp102_hwmon_ops, 169 .info = tmp102_info, 170 }; 171 172 static void tmp102_restore_config(void *data) 173 { 174 struct tmp102 *tmp102 = data; 175 176 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); 177 } 178 179 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) 180 { 181 return reg != TMP102_TEMP_REG; 182 } 183 184 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) 185 { 186 return reg == TMP102_TEMP_REG; 187 } 188 189 static const struct regmap_config tmp102_regmap_config = { 190 .reg_bits = 8, 191 .val_bits = 16, 192 .max_register = TMP102_THIGH_REG, 193 .writeable_reg = tmp102_is_writeable_reg, 194 .volatile_reg = tmp102_is_volatile_reg, 195 .val_format_endian = REGMAP_ENDIAN_BIG, 196 .cache_type = REGCACHE_RBTREE, 197 .use_single_read = true, 198 .use_single_write = true, 199 }; 200 201 static int tmp102_probe(struct i2c_client *client, 202 const struct i2c_device_id *id) 203 { 204 struct device *dev = &client->dev; 205 struct device *hwmon_dev; 206 struct tmp102 *tmp102; 207 unsigned int regval; 208 int err; 209 210 if (!i2c_check_functionality(client->adapter, 211 I2C_FUNC_SMBUS_WORD_DATA)) { 212 dev_err(dev, 213 "adapter doesn't support SMBus word transactions\n"); 214 return -ENODEV; 215 } 216 217 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 218 if (!tmp102) 219 return -ENOMEM; 220 221 i2c_set_clientdata(client, tmp102); 222 223 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); 224 if (IS_ERR(tmp102->regmap)) 225 return PTR_ERR(tmp102->regmap); 226 227 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); 228 if (err < 0) { 229 dev_err(dev, "error reading config register\n"); 230 return err; 231 } 232 233 if ((regval & ~TMP102_CONFREG_MASK) != 234 (TMP102_CONF_R0 | TMP102_CONF_R1)) { 235 dev_err(dev, "unexpected config register value\n"); 236 return -ENODEV; 237 } 238 239 tmp102->config_orig = regval; 240 241 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); 242 if (err) 243 return err; 244 245 regval &= ~TMP102_CONFIG_CLEAR; 246 regval |= TMP102_CONFIG_SET; 247 248 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); 249 if (err < 0) { 250 dev_err(dev, "error writing config register\n"); 251 return err; 252 } 253 254 /* 255 * Mark that we are not ready with data until the first 256 * conversion is complete 257 */ 258 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 259 260 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 261 tmp102, 262 &tmp102_chip_info, 263 NULL); 264 if (IS_ERR(hwmon_dev)) { 265 dev_dbg(dev, "unable to register hwmon device\n"); 266 return PTR_ERR(hwmon_dev); 267 } 268 dev_info(dev, "initialized\n"); 269 270 return 0; 271 } 272 273 #ifdef CONFIG_PM_SLEEP 274 static int tmp102_suspend(struct device *dev) 275 { 276 struct i2c_client *client = to_i2c_client(dev); 277 struct tmp102 *tmp102 = i2c_get_clientdata(client); 278 279 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 280 TMP102_CONF_SD, TMP102_CONF_SD); 281 } 282 283 static int tmp102_resume(struct device *dev) 284 { 285 struct i2c_client *client = to_i2c_client(dev); 286 struct tmp102 *tmp102 = i2c_get_clientdata(client); 287 int err; 288 289 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 290 TMP102_CONF_SD, 0); 291 292 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 293 294 return err; 295 } 296 #endif /* CONFIG_PM */ 297 298 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 299 300 static const struct i2c_device_id tmp102_id[] = { 301 { "tmp102", 0 }, 302 { } 303 }; 304 MODULE_DEVICE_TABLE(i2c, tmp102_id); 305 306 static const struct of_device_id __maybe_unused tmp102_of_match[] = { 307 { .compatible = "ti,tmp102" }, 308 { }, 309 }; 310 MODULE_DEVICE_TABLE(of, tmp102_of_match); 311 312 static struct i2c_driver tmp102_driver = { 313 .driver.name = DRIVER_NAME, 314 .driver.of_match_table = of_match_ptr(tmp102_of_match), 315 .driver.pm = &tmp102_dev_pm_ops, 316 .probe = tmp102_probe, 317 .id_table = tmp102_id, 318 }; 319 320 module_i2c_driver(tmp102_driver); 321 322 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 323 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 324 MODULE_LICENSE("GPL"); 325