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/thermal.h> 29 #include <linux/of.h> 30 31 #define DRIVER_NAME "tmp102" 32 33 #define TMP102_TEMP_REG 0x00 34 #define TMP102_CONF_REG 0x01 35 /* note: these bit definitions are byte swapped */ 36 #define TMP102_CONF_SD 0x0100 37 #define TMP102_CONF_TM 0x0200 38 #define TMP102_CONF_POL 0x0400 39 #define TMP102_CONF_F0 0x0800 40 #define TMP102_CONF_F1 0x1000 41 #define TMP102_CONF_R0 0x2000 42 #define TMP102_CONF_R1 0x4000 43 #define TMP102_CONF_OS 0x8000 44 #define TMP102_CONF_EM 0x0010 45 #define TMP102_CONF_AL 0x0020 46 #define TMP102_CONF_CR0 0x0040 47 #define TMP102_CONF_CR1 0x0080 48 #define TMP102_TLOW_REG 0x02 49 #define TMP102_THIGH_REG 0x03 50 51 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ 52 TMP102_CONF_POL | TMP102_CONF_F0 | \ 53 TMP102_CONF_F1 | TMP102_CONF_OS | \ 54 TMP102_CONF_EM | TMP102_CONF_AL | \ 55 TMP102_CONF_CR0 | TMP102_CONF_CR1) 56 57 #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ 58 TMP102_CONF_CR0) 59 #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ 60 TMP102_CONF_CR1) 61 62 #define CONVERSION_TIME_MS 35 /* in milli-seconds */ 63 64 struct tmp102 { 65 struct regmap *regmap; 66 u16 config_orig; 67 unsigned long ready_time; 68 }; 69 70 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 71 static inline int tmp102_reg_to_mC(s16 val) 72 { 73 return ((val & ~0x01) * 1000) / 128; 74 } 75 76 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 77 static inline u16 tmp102_mC_to_reg(int val) 78 { 79 return (val * 128) / 1000; 80 } 81 82 static int tmp102_read_temp(void *dev, int *temp) 83 { 84 struct tmp102 *tmp102 = dev_get_drvdata(dev); 85 unsigned int reg; 86 int ret; 87 88 if (time_before(jiffies, tmp102->ready_time)) { 89 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); 90 return -EAGAIN; 91 } 92 93 ret = regmap_read(tmp102->regmap, TMP102_TEMP_REG, ®); 94 if (ret < 0) 95 return ret; 96 97 *temp = tmp102_reg_to_mC(reg); 98 99 return 0; 100 } 101 102 static ssize_t tmp102_show_temp(struct device *dev, 103 struct device_attribute *attr, 104 char *buf) 105 { 106 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 107 struct tmp102 *tmp102 = dev_get_drvdata(dev); 108 int regaddr = sda->index; 109 unsigned int reg; 110 int err; 111 112 if (regaddr == TMP102_TEMP_REG && 113 time_before(jiffies, tmp102->ready_time)) 114 return -EAGAIN; 115 116 err = regmap_read(tmp102->regmap, regaddr, ®); 117 if (err < 0) 118 return err; 119 120 return sprintf(buf, "%d\n", tmp102_reg_to_mC(reg)); 121 } 122 123 static ssize_t tmp102_set_temp(struct device *dev, 124 struct device_attribute *attr, 125 const char *buf, size_t count) 126 { 127 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 128 struct tmp102 *tmp102 = dev_get_drvdata(dev); 129 int reg = sda->index; 130 long val; 131 int err; 132 133 if (kstrtol(buf, 10, &val) < 0) 134 return -EINVAL; 135 val = clamp_val(val, -256000, 255000); 136 137 err = regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(val)); 138 return err ? : count; 139 } 140 141 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL, 142 TMP102_TEMP_REG); 143 144 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 145 tmp102_set_temp, TMP102_TLOW_REG); 146 147 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 148 tmp102_set_temp, TMP102_THIGH_REG); 149 150 static struct attribute *tmp102_attrs[] = { 151 &sensor_dev_attr_temp1_input.dev_attr.attr, 152 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, 153 &sensor_dev_attr_temp1_max.dev_attr.attr, 154 NULL 155 }; 156 ATTRIBUTE_GROUPS(tmp102); 157 158 static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { 159 .get_temp = tmp102_read_temp, 160 }; 161 162 static void tmp102_restore_config(void *data) 163 { 164 struct tmp102 *tmp102 = data; 165 166 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); 167 } 168 169 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) 170 { 171 return reg != TMP102_TEMP_REG; 172 } 173 174 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) 175 { 176 return reg == TMP102_TEMP_REG; 177 } 178 179 static const struct regmap_config tmp102_regmap_config = { 180 .reg_bits = 8, 181 .val_bits = 16, 182 .max_register = TMP102_THIGH_REG, 183 .writeable_reg = tmp102_is_writeable_reg, 184 .volatile_reg = tmp102_is_volatile_reg, 185 .val_format_endian = REGMAP_ENDIAN_BIG, 186 .cache_type = REGCACHE_RBTREE, 187 .use_single_rw = true, 188 }; 189 190 static int tmp102_probe(struct i2c_client *client, 191 const struct i2c_device_id *id) 192 { 193 struct device *dev = &client->dev; 194 struct device *hwmon_dev; 195 struct tmp102 *tmp102; 196 unsigned int regval; 197 int err; 198 199 if (!i2c_check_functionality(client->adapter, 200 I2C_FUNC_SMBUS_WORD_DATA)) { 201 dev_err(dev, 202 "adapter doesn't support SMBus word transactions\n"); 203 return -ENODEV; 204 } 205 206 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 207 if (!tmp102) 208 return -ENOMEM; 209 210 i2c_set_clientdata(client, tmp102); 211 212 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); 213 if (IS_ERR(tmp102->regmap)) 214 return PTR_ERR(tmp102->regmap); 215 216 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); 217 if (err < 0) { 218 dev_err(dev, "error reading config register\n"); 219 return err; 220 } 221 222 if ((regval & ~TMP102_CONFREG_MASK) != 223 (TMP102_CONF_R0 | TMP102_CONF_R1)) { 224 dev_err(dev, "unexpected config register value\n"); 225 return -ENODEV; 226 } 227 228 tmp102->config_orig = regval; 229 230 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); 231 if (err) 232 return err; 233 234 regval &= ~TMP102_CONFIG_CLEAR; 235 regval |= TMP102_CONFIG_SET; 236 237 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); 238 if (err < 0) { 239 dev_err(dev, "error writing config register\n"); 240 return err; 241 } 242 243 tmp102->ready_time = jiffies; 244 if (tmp102->config_orig & TMP102_CONF_SD) { 245 /* 246 * Mark that we are not ready with data until the first 247 * conversion is complete 248 */ 249 tmp102->ready_time += msecs_to_jiffies(CONVERSION_TIME_MS); 250 } 251 252 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 253 tmp102, 254 tmp102_groups); 255 if (IS_ERR(hwmon_dev)) { 256 dev_dbg(dev, "unable to register hwmon device\n"); 257 return PTR_ERR(hwmon_dev); 258 } 259 devm_thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, 260 &tmp102_of_thermal_ops); 261 262 dev_info(dev, "initialized\n"); 263 264 return 0; 265 } 266 267 #ifdef CONFIG_PM_SLEEP 268 static int tmp102_suspend(struct device *dev) 269 { 270 struct i2c_client *client = to_i2c_client(dev); 271 struct tmp102 *tmp102 = i2c_get_clientdata(client); 272 273 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 274 TMP102_CONF_SD, TMP102_CONF_SD); 275 } 276 277 static int tmp102_resume(struct device *dev) 278 { 279 struct i2c_client *client = to_i2c_client(dev); 280 struct tmp102 *tmp102 = i2c_get_clientdata(client); 281 int err; 282 283 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, 284 TMP102_CONF_SD, 0); 285 286 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); 287 288 return err; 289 } 290 #endif /* CONFIG_PM */ 291 292 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 293 294 static const struct i2c_device_id tmp102_id[] = { 295 { "tmp102", 0 }, 296 { } 297 }; 298 MODULE_DEVICE_TABLE(i2c, tmp102_id); 299 300 static struct i2c_driver tmp102_driver = { 301 .driver.name = DRIVER_NAME, 302 .driver.pm = &tmp102_dev_pm_ops, 303 .probe = tmp102_probe, 304 .id_table = tmp102_id, 305 }; 306 307 module_i2c_driver(tmp102_driver); 308 309 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 310 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 311 MODULE_LICENSE("GPL"); 312