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 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 59 static inline int tmp102_reg_to_mC(s16 val) 60 { 61 return ((val & ~0x01) * 1000) / 128; 62 } 63 64 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 65 static inline u16 tmp102_mC_to_reg(int val) 66 { 67 return (val * 128) / 1000; 68 } 69 70 static const u8 tmp102_reg[] = { 71 TMP102_TEMP_REG, 72 TMP102_TLOW_REG, 73 TMP102_THIGH_REG, 74 }; 75 76 static struct tmp102 *tmp102_update_device(struct i2c_client *client) 77 { 78 struct tmp102 *tmp102 = i2c_get_clientdata(client); 79 80 mutex_lock(&tmp102->lock); 81 if (time_after(jiffies, tmp102->last_update + HZ / 3)) { 82 int i; 83 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { 84 int status = i2c_smbus_read_word_swapped(client, 85 tmp102_reg[i]); 86 if (status > -1) 87 tmp102->temp[i] = tmp102_reg_to_mC(status); 88 } 89 tmp102->last_update = jiffies; 90 } 91 mutex_unlock(&tmp102->lock); 92 return tmp102; 93 } 94 95 static ssize_t tmp102_show_temp(struct device *dev, 96 struct device_attribute *attr, 97 char *buf) 98 { 99 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 100 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev)); 101 102 return sprintf(buf, "%d\n", tmp102->temp[sda->index]); 103 } 104 105 static ssize_t tmp102_set_temp(struct device *dev, 106 struct device_attribute *attr, 107 const char *buf, size_t count) 108 { 109 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 110 struct i2c_client *client = to_i2c_client(dev); 111 struct tmp102 *tmp102 = i2c_get_clientdata(client); 112 long val; 113 int status; 114 115 if (kstrtol(buf, 10, &val) < 0) 116 return -EINVAL; 117 val = SENSORS_LIMIT(val, -256000, 255000); 118 119 mutex_lock(&tmp102->lock); 120 tmp102->temp[sda->index] = val; 121 status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index], 122 tmp102_mC_to_reg(val)); 123 mutex_unlock(&tmp102->lock); 124 return status ? : count; 125 } 126 127 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); 128 129 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 130 tmp102_set_temp, 1); 131 132 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 133 tmp102_set_temp, 2); 134 135 static struct attribute *tmp102_attributes[] = { 136 &sensor_dev_attr_temp1_input.dev_attr.attr, 137 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, 138 &sensor_dev_attr_temp1_max.dev_attr.attr, 139 NULL 140 }; 141 142 static const struct attribute_group tmp102_attr_group = { 143 .attrs = tmp102_attributes, 144 }; 145 146 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1) 147 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL) 148 149 static int __devinit tmp102_probe(struct i2c_client *client, 150 const struct i2c_device_id *id) 151 { 152 struct tmp102 *tmp102; 153 int status; 154 155 if (!i2c_check_functionality(client->adapter, 156 I2C_FUNC_SMBUS_WORD_DATA)) { 157 dev_err(&client->dev, "adapter doesn't support SMBus word " 158 "transactions\n"); 159 return -ENODEV; 160 } 161 162 tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL); 163 if (!tmp102) { 164 dev_dbg(&client->dev, "kzalloc failed\n"); 165 return -ENOMEM; 166 } 167 i2c_set_clientdata(client, tmp102); 168 169 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 170 if (status < 0) { 171 dev_err(&client->dev, "error reading config register\n"); 172 goto fail_free; 173 } 174 tmp102->config_orig = status; 175 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 176 TMP102_CONFIG); 177 if (status < 0) { 178 dev_err(&client->dev, "error writing config register\n"); 179 goto fail_restore_config; 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 goto fail_restore_config; 185 } 186 status &= ~TMP102_CONFIG_RD_ONLY; 187 if (status != TMP102_CONFIG) { 188 dev_err(&client->dev, "config settings did not stick\n"); 189 status = -ENODEV; 190 goto fail_restore_config; 191 } 192 tmp102->last_update = jiffies - HZ; 193 mutex_init(&tmp102->lock); 194 195 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group); 196 if (status) { 197 dev_dbg(&client->dev, "could not create sysfs files\n"); 198 goto fail_restore_config; 199 } 200 tmp102->hwmon_dev = hwmon_device_register(&client->dev); 201 if (IS_ERR(tmp102->hwmon_dev)) { 202 dev_dbg(&client->dev, "unable to register hwmon device\n"); 203 status = PTR_ERR(tmp102->hwmon_dev); 204 goto fail_remove_sysfs; 205 } 206 207 dev_info(&client->dev, "initialized\n"); 208 209 return 0; 210 211 fail_remove_sysfs: 212 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 213 fail_restore_config: 214 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 215 tmp102->config_orig); 216 fail_free: 217 kfree(tmp102); 218 219 return status; 220 } 221 222 static int __devexit tmp102_remove(struct i2c_client *client) 223 { 224 struct tmp102 *tmp102 = i2c_get_clientdata(client); 225 226 hwmon_device_unregister(tmp102->hwmon_dev); 227 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group); 228 229 /* Stop monitoring if device was stopped originally */ 230 if (tmp102->config_orig & TMP102_CONF_SD) { 231 int config; 232 233 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 234 if (config >= 0) 235 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 236 config | TMP102_CONF_SD); 237 } 238 239 kfree(tmp102); 240 241 return 0; 242 } 243 244 #ifdef CONFIG_PM 245 static int tmp102_suspend(struct device *dev) 246 { 247 struct i2c_client *client = to_i2c_client(dev); 248 int config; 249 250 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 251 if (config < 0) 252 return config; 253 254 config |= TMP102_CONF_SD; 255 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 256 } 257 258 static int tmp102_resume(struct device *dev) 259 { 260 struct i2c_client *client = to_i2c_client(dev); 261 int config; 262 263 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 264 if (config < 0) 265 return config; 266 267 config &= ~TMP102_CONF_SD; 268 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 269 } 270 271 static const struct dev_pm_ops tmp102_dev_pm_ops = { 272 .suspend = tmp102_suspend, 273 .resume = tmp102_resume, 274 }; 275 276 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops) 277 #else 278 #define TMP102_DEV_PM_OPS NULL 279 #endif /* CONFIG_PM */ 280 281 static const struct i2c_device_id tmp102_id[] = { 282 { "tmp102", 0 }, 283 { } 284 }; 285 MODULE_DEVICE_TABLE(i2c, tmp102_id); 286 287 static struct i2c_driver tmp102_driver = { 288 .driver.name = DRIVER_NAME, 289 .driver.pm = TMP102_DEV_PM_OPS, 290 .probe = tmp102_probe, 291 .remove = __devexit_p(tmp102_remove), 292 .id_table = tmp102_id, 293 }; 294 295 static int __init tmp102_init(void) 296 { 297 return i2c_add_driver(&tmp102_driver); 298 } 299 module_init(tmp102_init); 300 301 static void __exit tmp102_exit(void) 302 { 303 i2c_del_driver(&tmp102_driver); 304 } 305 module_exit(tmp102_exit); 306 307 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 308 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 309 MODULE_LICENSE("GPL"); 310