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 i2c_client *client; 55 struct device *hwmon_dev; 56 struct thermal_zone_device *tz; 57 struct mutex lock; 58 u16 config_orig; 59 unsigned long last_update; 60 int temp[3]; 61 }; 62 63 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ 64 static inline int tmp102_reg_to_mC(s16 val) 65 { 66 return ((val & ~0x01) * 1000) / 128; 67 } 68 69 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ 70 static inline u16 tmp102_mC_to_reg(int val) 71 { 72 return (val * 128) / 1000; 73 } 74 75 static const u8 tmp102_reg[] = { 76 TMP102_TEMP_REG, 77 TMP102_TLOW_REG, 78 TMP102_THIGH_REG, 79 }; 80 81 static struct tmp102 *tmp102_update_device(struct device *dev) 82 { 83 struct tmp102 *tmp102 = dev_get_drvdata(dev); 84 struct i2c_client *client = tmp102->client; 85 86 mutex_lock(&tmp102->lock); 87 if (time_after(jiffies, tmp102->last_update + HZ / 3)) { 88 int i; 89 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { 90 int status = i2c_smbus_read_word_swapped(client, 91 tmp102_reg[i]); 92 if (status > -1) 93 tmp102->temp[i] = tmp102_reg_to_mC(status); 94 } 95 tmp102->last_update = jiffies; 96 } 97 mutex_unlock(&tmp102->lock); 98 return tmp102; 99 } 100 101 static int tmp102_read_temp(void *dev, long *temp) 102 { 103 struct tmp102 *tmp102 = tmp102_update_device(dev); 104 105 *temp = tmp102->temp[0]; 106 107 return 0; 108 } 109 110 static ssize_t tmp102_show_temp(struct device *dev, 111 struct device_attribute *attr, 112 char *buf) 113 { 114 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 115 struct tmp102 *tmp102 = tmp102_update_device(dev); 116 117 return sprintf(buf, "%d\n", tmp102->temp[sda->index]); 118 } 119 120 static ssize_t tmp102_set_temp(struct device *dev, 121 struct device_attribute *attr, 122 const char *buf, size_t count) 123 { 124 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 125 struct tmp102 *tmp102 = dev_get_drvdata(dev); 126 struct i2c_client *client = tmp102->client; 127 long val; 128 int status; 129 130 if (kstrtol(buf, 10, &val) < 0) 131 return -EINVAL; 132 val = clamp_val(val, -256000, 255000); 133 134 mutex_lock(&tmp102->lock); 135 tmp102->temp[sda->index] = val; 136 status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index], 137 tmp102_mC_to_reg(val)); 138 mutex_unlock(&tmp102->lock); 139 return status ? : count; 140 } 141 142 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); 143 144 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 145 tmp102_set_temp, 1); 146 147 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 148 tmp102_set_temp, 2); 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 #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 const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { 162 .get_temp = tmp102_read_temp, 163 }; 164 165 static int tmp102_probe(struct i2c_client *client, 166 const struct i2c_device_id *id) 167 { 168 struct device *dev = &client->dev; 169 struct device *hwmon_dev; 170 struct tmp102 *tmp102; 171 int status; 172 173 if (!i2c_check_functionality(client->adapter, 174 I2C_FUNC_SMBUS_WORD_DATA)) { 175 dev_err(dev, 176 "adapter doesn't support SMBus word transactions\n"); 177 return -ENODEV; 178 } 179 180 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 181 if (!tmp102) 182 return -ENOMEM; 183 184 i2c_set_clientdata(client, tmp102); 185 tmp102->client = client; 186 187 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 188 if (status < 0) { 189 dev_err(dev, "error reading config register\n"); 190 return status; 191 } 192 tmp102->config_orig = status; 193 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 194 TMP102_CONFIG); 195 if (status < 0) { 196 dev_err(dev, "error writing config register\n"); 197 goto fail_restore_config; 198 } 199 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 200 if (status < 0) { 201 dev_err(dev, "error reading config register\n"); 202 goto fail_restore_config; 203 } 204 status &= ~TMP102_CONFIG_RD_ONLY; 205 if (status != TMP102_CONFIG) { 206 dev_err(dev, "config settings did not stick\n"); 207 status = -ENODEV; 208 goto fail_restore_config; 209 } 210 tmp102->last_update = jiffies - HZ; 211 mutex_init(&tmp102->lock); 212 213 hwmon_dev = hwmon_device_register_with_groups(dev, client->name, 214 tmp102, tmp102_groups); 215 if (IS_ERR(hwmon_dev)) { 216 dev_dbg(dev, "unable to register hwmon device\n"); 217 status = PTR_ERR(hwmon_dev); 218 goto fail_restore_config; 219 } 220 tmp102->hwmon_dev = hwmon_dev; 221 tmp102->tz = thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, 222 &tmp102_of_thermal_ops); 223 if (IS_ERR(tmp102->tz)) 224 tmp102->tz = NULL; 225 226 dev_info(dev, "initialized\n"); 227 228 return 0; 229 230 fail_restore_config: 231 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 232 tmp102->config_orig); 233 return status; 234 } 235 236 static int tmp102_remove(struct i2c_client *client) 237 { 238 struct tmp102 *tmp102 = i2c_get_clientdata(client); 239 240 thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz); 241 hwmon_device_unregister(tmp102->hwmon_dev); 242 243 /* Stop monitoring if device was stopped originally */ 244 if (tmp102->config_orig & TMP102_CONF_SD) { 245 int config; 246 247 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 248 if (config >= 0) 249 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 250 config | TMP102_CONF_SD); 251 } 252 253 return 0; 254 } 255 256 #ifdef CONFIG_PM_SLEEP 257 static int tmp102_suspend(struct device *dev) 258 { 259 struct i2c_client *client = to_i2c_client(dev); 260 int config; 261 262 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 263 if (config < 0) 264 return config; 265 266 config |= TMP102_CONF_SD; 267 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 268 } 269 270 static int tmp102_resume(struct device *dev) 271 { 272 struct i2c_client *client = to_i2c_client(dev); 273 int config; 274 275 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 276 if (config < 0) 277 return config; 278 279 config &= ~TMP102_CONF_SD; 280 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 281 } 282 #endif /* CONFIG_PM */ 283 284 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 285 286 static const struct i2c_device_id tmp102_id[] = { 287 { "tmp102", 0 }, 288 { } 289 }; 290 MODULE_DEVICE_TABLE(i2c, tmp102_id); 291 292 static struct i2c_driver tmp102_driver = { 293 .driver.name = DRIVER_NAME, 294 .driver.pm = &tmp102_dev_pm_ops, 295 .probe = tmp102_probe, 296 .remove = tmp102_remove, 297 .id_table = tmp102_id, 298 }; 299 300 module_i2c_driver(tmp102_driver); 301 302 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 303 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 304 MODULE_LICENSE("GPL"); 305