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 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA 18 */ 19 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/slab.h> 23 #include <linux/i2c.h> 24 #include <linux/hwmon.h> 25 #include <linux/hwmon-sysfs.h> 26 #include <linux/err.h> 27 #include <linux/mutex.h> 28 #include <linux/device.h> 29 #include <linux/jiffies.h> 30 #include <linux/thermal.h> 31 #include <linux/of.h> 32 33 #define DRIVER_NAME "tmp102" 34 35 #define TMP102_TEMP_REG 0x00 36 #define TMP102_CONF_REG 0x01 37 /* note: these bit definitions are byte swapped */ 38 #define TMP102_CONF_SD 0x0100 39 #define TMP102_CONF_TM 0x0200 40 #define TMP102_CONF_POL 0x0400 41 #define TMP102_CONF_F0 0x0800 42 #define TMP102_CONF_F1 0x1000 43 #define TMP102_CONF_R0 0x2000 44 #define TMP102_CONF_R1 0x4000 45 #define TMP102_CONF_OS 0x8000 46 #define TMP102_CONF_EM 0x0010 47 #define TMP102_CONF_AL 0x0020 48 #define TMP102_CONF_CR0 0x0040 49 #define TMP102_CONF_CR1 0x0080 50 #define TMP102_TLOW_REG 0x02 51 #define TMP102_THIGH_REG 0x03 52 53 struct tmp102 { 54 struct device *hwmon_dev; 55 struct thermal_zone_device *tz; 56 struct mutex lock; 57 u16 config_orig; 58 unsigned long last_update; 59 int temp[3]; 60 }; 61 62 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 63 static inline int tmp102_reg_to_mC(s16 val) 64 { 65 return ((val & ~0x01) * 1000) / 128; 66 } 67 68 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 69 static inline u16 tmp102_mC_to_reg(int val) 70 { 71 return (val * 128) / 1000; 72 } 73 74 static const u8 tmp102_reg[] = { 75 TMP102_TEMP_REG, 76 TMP102_TLOW_REG, 77 TMP102_THIGH_REG, 78 }; 79 80 static struct tmp102 *tmp102_update_device(struct i2c_client *client) 81 { 82 struct tmp102 *tmp102 = i2c_get_clientdata(client); 83 84 mutex_lock(&tmp102->lock); 85 if (time_after(jiffies, tmp102->last_update + HZ / 3)) { 86 int i; 87 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { 88 int status = i2c_smbus_read_word_swapped(client, 89 tmp102_reg[i]); 90 if (status > -1) 91 tmp102->temp[i] = tmp102_reg_to_mC(status); 92 } 93 tmp102->last_update = jiffies; 94 } 95 mutex_unlock(&tmp102->lock); 96 return tmp102; 97 } 98 99 static int tmp102_read_temp(void *dev, long *temp) 100 { 101 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev)); 102 103 *temp = tmp102->temp[0]; 104 105 return 0; 106 } 107 108 static ssize_t tmp102_show_temp(struct device *dev, 109 struct device_attribute *attr, 110 char *buf) 111 { 112 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 113 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev)); 114 115 return sprintf(buf, "%d\n", tmp102->temp[sda->index]); 116 } 117 118 static ssize_t tmp102_set_temp(struct device *dev, 119 struct device_attribute *attr, 120 const char *buf, size_t count) 121 { 122 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 123 struct i2c_client *client = to_i2c_client(dev); 124 struct tmp102 *tmp102 = i2c_get_clientdata(client); 125 long val; 126 int status; 127 128 if (kstrtol(buf, 10, &val) < 0) 129 return -EINVAL; 130 val = clamp_val(val, -256000, 255000); 131 132 mutex_lock(&tmp102->lock); 133 tmp102->temp[sda->index] = val; 134 status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index], 135 tmp102_mC_to_reg(val)); 136 mutex_unlock(&tmp102->lock); 137 return status ? : count; 138 } 139 140 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); 141 142 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 143 tmp102_set_temp, 1); 144 145 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 146 tmp102_set_temp, 2); 147 148 static struct attribute *tmp102_attributes[] = { 149 &sensor_dev_attr_temp1_input.dev_attr.attr, 150 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, 151 &sensor_dev_attr_temp1_max.dev_attr.attr, 152 NULL 153 }; 154 155 static const struct attribute_group tmp102_attr_group = { 156 .attrs = tmp102_attributes, 157 }; 158 159 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1) 160 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL) 161 162 static int tmp102_probe(struct i2c_client *client, 163 const struct i2c_device_id *id) 164 { 165 struct tmp102 *tmp102; 166 int status; 167 168 if (!i2c_check_functionality(client->adapter, 169 I2C_FUNC_SMBUS_WORD_DATA)) { 170 dev_err(&client->dev, 171 "adapter doesn't support SMBus word transactions\n"); 172 return -ENODEV; 173 } 174 175 tmp102 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL); 176 if (!tmp102) 177 return -ENOMEM; 178 179 i2c_set_clientdata(client, tmp102); 180 181 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 182 if (status < 0) { 183 dev_err(&client->dev, "error reading config register\n"); 184 return status; 185 } 186 tmp102->config_orig = status; 187 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 188 TMP102_CONFIG); 189 if (status < 0) { 190 dev_err(&client->dev, "error writing config register\n"); 191 goto fail_restore_config; 192 } 193 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 194 if (status < 0) { 195 dev_err(&client->dev, "error reading config register\n"); 196 goto fail_restore_config; 197 } 198 status &= ~TMP102_CONFIG_RD_ONLY; 199 if (status != TMP102_CONFIG) { 200 dev_err(&client->dev, "config settings did not stick\n"); 201 status = -ENODEV; 202 goto fail_restore_config; 203 } 204 tmp102->last_update = jiffies - HZ; 205 mutex_init(&tmp102->lock); 206 207 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group); 208 if (status) { 209 dev_dbg(&client->dev, "could not create sysfs files\n"); 210 goto fail_restore_config; 211 } 212 tmp102->hwmon_dev = hwmon_device_register(&client->dev); 213 if (IS_ERR(tmp102->hwmon_dev)) { 214 dev_dbg(&client->dev, "unable to register hwmon device\n"); 215 status = PTR_ERR(tmp102->hwmon_dev); 216 goto fail_remove_sysfs; 217 } 218 219 tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0, 220 &client->dev, 221 tmp102_read_temp, NULL); 222 if (IS_ERR(tmp102->tz)) 223 tmp102->tz = NULL; 224 225 dev_info(&client->dev, "initialized\n"); 226 227 return 0; 228 229 fail_remove_sysfs: 230 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 231 fail_restore_config: 232 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 233 tmp102->config_orig); 234 return status; 235 } 236 237 static int tmp102_remove(struct i2c_client *client) 238 { 239 struct tmp102 *tmp102 = i2c_get_clientdata(client); 240 241 thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz); 242 hwmon_device_unregister(tmp102->hwmon_dev); 243 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 244 245 /* Stop monitoring if device was stopped originally */ 246 if (tmp102->config_orig & TMP102_CONF_SD) { 247 int config; 248 249 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 250 if (config >= 0) 251 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 252 config | TMP102_CONF_SD); 253 } 254 255 return 0; 256 } 257 258 #ifdef CONFIG_PM 259 static int tmp102_suspend(struct device *dev) 260 { 261 struct i2c_client *client = to_i2c_client(dev); 262 int config; 263 264 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 265 if (config < 0) 266 return config; 267 268 config |= TMP102_CONF_SD; 269 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 270 } 271 272 static int tmp102_resume(struct device *dev) 273 { 274 struct i2c_client *client = to_i2c_client(dev); 275 int config; 276 277 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 278 if (config < 0) 279 return config; 280 281 config &= ~TMP102_CONF_SD; 282 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 283 } 284 285 static const struct dev_pm_ops tmp102_dev_pm_ops = { 286 .suspend = tmp102_suspend, 287 .resume = tmp102_resume, 288 }; 289 290 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops) 291 #else 292 #define TMP102_DEV_PM_OPS NULL 293 #endif /* CONFIG_PM */ 294 295 static const struct i2c_device_id tmp102_id[] = { 296 { "tmp102", 0 }, 297 { } 298 }; 299 MODULE_DEVICE_TABLE(i2c, tmp102_id); 300 301 static struct i2c_driver tmp102_driver = { 302 .driver.name = DRIVER_NAME, 303 .driver.pm = TMP102_DEV_PM_OPS, 304 .probe = tmp102_probe, 305 .remove = tmp102_remove, 306 .id_table = tmp102_id, 307 }; 308 309 module_i2c_driver(tmp102_driver); 310 311 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 312 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 313 MODULE_LICENSE("GPL"); 314