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 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 struct tmp102 { 51 struct device *hwmon_dev; 52 struct mutex lock; 53 u16 config_orig; 54 unsigned long last_update; 55 int temp[3]; 56 }; 57 58 /* SMBus specifies low byte first, but the TMP102 returns high byte first, 59 * so we have to swab16 the values */ 60 static inline int tmp102_read_reg(struct i2c_client *client, u8 reg) 61 { 62 int result = i2c_smbus_read_word_data(client, reg); 63 return result < 0 ? result : swab16(result); 64 } 65 66 static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val) 67 { 68 return i2c_smbus_write_word_data(client, reg, swab16(val)); 69 } 70 71 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 72 static inline int tmp102_reg_to_mC(s16 val) 73 { 74 return ((val & ~0x01) * 1000) / 128; 75 } 76 77 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 78 static inline u16 tmp102_mC_to_reg(int val) 79 { 80 return (val * 128) / 1000; 81 } 82 83 static const u8 tmp102_reg[] = { 84 TMP102_TEMP_REG, 85 TMP102_TLOW_REG, 86 TMP102_THIGH_REG, 87 }; 88 89 static struct tmp102 *tmp102_update_device(struct i2c_client *client) 90 { 91 struct tmp102 *tmp102 = i2c_get_clientdata(client); 92 93 mutex_lock(&tmp102->lock); 94 if (time_after(jiffies, tmp102->last_update + HZ / 3)) { 95 int i; 96 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { 97 int status = tmp102_read_reg(client, tmp102_reg[i]); 98 if (status > -1) 99 tmp102->temp[i] = tmp102_reg_to_mC(status); 100 } 101 tmp102->last_update = jiffies; 102 } 103 mutex_unlock(&tmp102->lock); 104 return tmp102; 105 } 106 107 static ssize_t tmp102_show_temp(struct device *dev, 108 struct device_attribute *attr, 109 char *buf) 110 { 111 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 112 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev)); 113 114 return sprintf(buf, "%d\n", tmp102->temp[sda->index]); 115 } 116 117 static ssize_t tmp102_set_temp(struct device *dev, 118 struct device_attribute *attr, 119 const char *buf, size_t count) 120 { 121 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 122 struct i2c_client *client = to_i2c_client(dev); 123 struct tmp102 *tmp102 = i2c_get_clientdata(client); 124 long val; 125 int status; 126 127 if (strict_strtol(buf, 10, &val) < 0) 128 return -EINVAL; 129 val = SENSORS_LIMIT(val, -256000, 255000); 130 131 mutex_lock(&tmp102->lock); 132 tmp102->temp[sda->index] = val; 133 status = tmp102_write_reg(client, tmp102_reg[sda->index], 134 tmp102_mC_to_reg(val)); 135 mutex_unlock(&tmp102->lock); 136 return status ? : count; 137 } 138 139 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); 140 141 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 142 tmp102_set_temp, 1); 143 144 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 145 tmp102_set_temp, 2); 146 147 static struct attribute *tmp102_attributes[] = { 148 &sensor_dev_attr_temp1_input.dev_attr.attr, 149 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, 150 &sensor_dev_attr_temp1_max.dev_attr.attr, 151 NULL 152 }; 153 154 static const struct attribute_group tmp102_attr_group = { 155 .attrs = tmp102_attributes, 156 }; 157 158 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1) 159 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL) 160 161 static int __devinit tmp102_probe(struct i2c_client *client, 162 const struct i2c_device_id *id) 163 { 164 struct tmp102 *tmp102; 165 int status; 166 167 if (!i2c_check_functionality(client->adapter, 168 I2C_FUNC_SMBUS_WORD_DATA)) { 169 dev_err(&client->dev, "adapter doesn't support SMBus word " 170 "transactions\n"); 171 return -ENODEV; 172 } 173 174 tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL); 175 if (!tmp102) { 176 dev_dbg(&client->dev, "kzalloc failed\n"); 177 return -ENOMEM; 178 } 179 i2c_set_clientdata(client, tmp102); 180 181 status = tmp102_read_reg(client, TMP102_CONF_REG); 182 if (status < 0) { 183 dev_err(&client->dev, "error reading config register\n"); 184 goto fail_free; 185 } 186 tmp102->config_orig = status; 187 status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG); 188 if (status < 0) { 189 dev_err(&client->dev, "error writing config register\n"); 190 goto fail_restore_config; 191 } 192 status = tmp102_read_reg(client, TMP102_CONF_REG); 193 if (status < 0) { 194 dev_err(&client->dev, "error reading config register\n"); 195 goto fail_restore_config; 196 } 197 status &= ~TMP102_CONFIG_RD_ONLY; 198 if (status != TMP102_CONFIG) { 199 dev_err(&client->dev, "config settings did not stick\n"); 200 status = -ENODEV; 201 goto fail_restore_config; 202 } 203 tmp102->last_update = jiffies - HZ; 204 mutex_init(&tmp102->lock); 205 206 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group); 207 if (status) { 208 dev_dbg(&client->dev, "could not create sysfs files\n"); 209 goto fail_restore_config; 210 } 211 tmp102->hwmon_dev = hwmon_device_register(&client->dev); 212 if (IS_ERR(tmp102->hwmon_dev)) { 213 dev_dbg(&client->dev, "unable to register hwmon device\n"); 214 status = PTR_ERR(tmp102->hwmon_dev); 215 goto fail_remove_sysfs; 216 } 217 218 dev_info(&client->dev, "initialized\n"); 219 220 return 0; 221 222 fail_remove_sysfs: 223 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 224 fail_restore_config: 225 tmp102_write_reg(client, TMP102_CONF_REG, tmp102->config_orig); 226 fail_free: 227 kfree(tmp102); 228 229 return status; 230 } 231 232 static int __devexit tmp102_remove(struct i2c_client *client) 233 { 234 struct tmp102 *tmp102 = i2c_get_clientdata(client); 235 236 hwmon_device_unregister(tmp102->hwmon_dev); 237 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 238 239 /* Stop monitoring if device was stopped originally */ 240 if (tmp102->config_orig & TMP102_CONF_SD) { 241 int config; 242 243 config = tmp102_read_reg(client, TMP102_CONF_REG); 244 if (config >= 0) 245 tmp102_write_reg(client, TMP102_CONF_REG, 246 config | TMP102_CONF_SD); 247 } 248 249 kfree(tmp102); 250 251 return 0; 252 } 253 254 #ifdef CONFIG_PM 255 static int tmp102_suspend(struct device *dev) 256 { 257 struct i2c_client *client = to_i2c_client(dev); 258 int config; 259 260 config = tmp102_read_reg(client, TMP102_CONF_REG); 261 if (config < 0) 262 return config; 263 264 config |= TMP102_CONF_SD; 265 return tmp102_write_reg(client, TMP102_CONF_REG, config); 266 } 267 268 static int tmp102_resume(struct device *dev) 269 { 270 struct i2c_client *client = to_i2c_client(dev); 271 int config; 272 273 config = tmp102_read_reg(client, TMP102_CONF_REG); 274 if (config < 0) 275 return config; 276 277 config &= ~TMP102_CONF_SD; 278 return tmp102_write_reg(client, TMP102_CONF_REG, config); 279 } 280 281 static const struct dev_pm_ops tmp102_dev_pm_ops = { 282 .suspend = tmp102_suspend, 283 .resume = tmp102_resume, 284 }; 285 286 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops) 287 #else 288 #define TMP102_DEV_PM_OPS NULL 289 #endif /* CONFIG_PM */ 290 291 static const struct i2c_device_id tmp102_id[] = { 292 { "tmp102", 0 }, 293 { } 294 }; 295 MODULE_DEVICE_TABLE(i2c, tmp102_id); 296 297 static struct i2c_driver tmp102_driver = { 298 .driver.name = DRIVER_NAME, 299 .driver.pm = TMP102_DEV_PM_OPS, 300 .probe = tmp102_probe, 301 .remove = __devexit_p(tmp102_remove), 302 .id_table = tmp102_id, 303 }; 304 305 static int __init tmp102_init(void) 306 { 307 return i2c_add_driver(&tmp102_driver); 308 } 309 module_init(tmp102_init); 310 311 static void __exit tmp102_exit(void) 312 { 313 i2c_del_driver(&tmp102_driver); 314 } 315 module_exit(tmp102_exit); 316 317 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 318 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 319 MODULE_LICENSE("GPL"); 320