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 mutex lock; 57 u16 config_orig; 58 unsigned long last_update; 59 int temp[3]; 60 bool first_time; 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 tmp102->first_time = false; 97 } 98 mutex_unlock(&tmp102->lock); 99 return tmp102; 100 } 101 102 static int tmp102_read_temp(void *dev, int *temp) 103 { 104 struct tmp102 *tmp102 = tmp102_update_device(dev); 105 106 /* Is it too early even to return a conversion? */ 107 if (tmp102->first_time) { 108 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); 109 return -EAGAIN; 110 } 111 112 *temp = tmp102->temp[0]; 113 114 return 0; 115 } 116 117 static ssize_t tmp102_show_temp(struct device *dev, 118 struct device_attribute *attr, 119 char *buf) 120 { 121 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 122 struct tmp102 *tmp102 = tmp102_update_device(dev); 123 124 /* Is it too early even to return a read? */ 125 if (tmp102->first_time) 126 return -EAGAIN; 127 128 return sprintf(buf, "%d\n", tmp102->temp[sda->index]); 129 } 130 131 static ssize_t tmp102_set_temp(struct device *dev, 132 struct device_attribute *attr, 133 const char *buf, size_t count) 134 { 135 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); 136 struct tmp102 *tmp102 = dev_get_drvdata(dev); 137 struct i2c_client *client = tmp102->client; 138 long val; 139 int status; 140 141 if (kstrtol(buf, 10, &val) < 0) 142 return -EINVAL; 143 val = clamp_val(val, -256000, 255000); 144 145 mutex_lock(&tmp102->lock); 146 tmp102->temp[sda->index] = val; 147 status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index], 148 tmp102_mC_to_reg(val)); 149 mutex_unlock(&tmp102->lock); 150 return status ? : count; 151 } 152 153 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); 154 155 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, 156 tmp102_set_temp, 1); 157 158 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, 159 tmp102_set_temp, 2); 160 161 static struct attribute *tmp102_attrs[] = { 162 &sensor_dev_attr_temp1_input.dev_attr.attr, 163 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, 164 &sensor_dev_attr_temp1_max.dev_attr.attr, 165 NULL 166 }; 167 ATTRIBUTE_GROUPS(tmp102); 168 169 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1) 170 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL) 171 172 static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { 173 .get_temp = tmp102_read_temp, 174 }; 175 176 static int tmp102_probe(struct i2c_client *client, 177 const struct i2c_device_id *id) 178 { 179 struct device *dev = &client->dev; 180 struct device *hwmon_dev; 181 struct tmp102 *tmp102; 182 int status; 183 184 if (!i2c_check_functionality(client->adapter, 185 I2C_FUNC_SMBUS_WORD_DATA)) { 186 dev_err(dev, 187 "adapter doesn't support SMBus word transactions\n"); 188 return -ENODEV; 189 } 190 191 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); 192 if (!tmp102) 193 return -ENOMEM; 194 195 i2c_set_clientdata(client, tmp102); 196 tmp102->client = client; 197 198 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 199 if (status < 0) { 200 dev_err(dev, "error reading config register\n"); 201 return status; 202 } 203 tmp102->config_orig = status; 204 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 205 TMP102_CONFIG); 206 if (status < 0) { 207 dev_err(dev, "error writing config register\n"); 208 goto fail_restore_config; 209 } 210 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 211 if (status < 0) { 212 dev_err(dev, "error reading config register\n"); 213 goto fail_restore_config; 214 } 215 status &= ~TMP102_CONFIG_RD_ONLY; 216 if (status != TMP102_CONFIG) { 217 dev_err(dev, "config settings did not stick\n"); 218 status = -ENODEV; 219 goto fail_restore_config; 220 } 221 tmp102->last_update = jiffies; 222 /* Mark that we are not ready with data until conversion is complete */ 223 tmp102->first_time = true; 224 mutex_init(&tmp102->lock); 225 226 hwmon_dev = hwmon_device_register_with_groups(dev, client->name, 227 tmp102, tmp102_groups); 228 if (IS_ERR(hwmon_dev)) { 229 dev_dbg(dev, "unable to register hwmon device\n"); 230 status = PTR_ERR(hwmon_dev); 231 goto fail_restore_config; 232 } 233 tmp102->hwmon_dev = hwmon_dev; 234 devm_thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, 235 &tmp102_of_thermal_ops); 236 237 dev_info(dev, "initialized\n"); 238 239 return 0; 240 241 fail_restore_config: 242 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 243 tmp102->config_orig); 244 return status; 245 } 246 247 static int tmp102_remove(struct i2c_client *client) 248 { 249 struct tmp102 *tmp102 = i2c_get_clientdata(client); 250 251 hwmon_device_unregister(tmp102->hwmon_dev); 252 253 /* Stop monitoring if device was stopped originally */ 254 if (tmp102->config_orig & TMP102_CONF_SD) { 255 int config; 256 257 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 258 if (config >= 0) 259 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, 260 config | TMP102_CONF_SD); 261 } 262 263 return 0; 264 } 265 266 #ifdef CONFIG_PM_SLEEP 267 static int tmp102_suspend(struct device *dev) 268 { 269 struct i2c_client *client = to_i2c_client(dev); 270 int config; 271 272 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 273 if (config < 0) 274 return config; 275 276 config |= TMP102_CONF_SD; 277 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 278 } 279 280 static int tmp102_resume(struct device *dev) 281 { 282 struct i2c_client *client = to_i2c_client(dev); 283 int config; 284 285 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); 286 if (config < 0) 287 return config; 288 289 config &= ~TMP102_CONF_SD; 290 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); 291 } 292 #endif /* CONFIG_PM */ 293 294 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); 295 296 static const struct i2c_device_id tmp102_id[] = { 297 { "tmp102", 0 }, 298 { } 299 }; 300 MODULE_DEVICE_TABLE(i2c, tmp102_id); 301 302 static struct i2c_driver tmp102_driver = { 303 .driver.name = DRIVER_NAME, 304 .driver.pm = &tmp102_dev_pm_ops, 305 .probe = tmp102_probe, 306 .remove = tmp102_remove, 307 .id_table = tmp102_id, 308 }; 309 310 module_i2c_driver(tmp102_driver); 311 312 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 313 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); 314 MODULE_LICENSE("GPL"); 315