| 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 | bool first_time; |
| 62 | }; |
| 63 | |
| 64 | /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ |
| 65 | static inline int tmp102_reg_to_mC(s16 val) |
| 66 | { |
| 67 | return ((val & ~0x01) * 1000) / 128; |
| 68 | } |
| 69 | |
| 70 | /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ |
| 71 | static inline u16 tmp102_mC_to_reg(int val) |
| 72 | { |
| 73 | return (val * 128) / 1000; |
| 74 | } |
| 75 | |
| 76 | static const u8 tmp102_reg[] = { |
| 77 | TMP102_TEMP_REG, |
| 78 | TMP102_TLOW_REG, |
| 79 | TMP102_THIGH_REG, |
| 80 | }; |
| 81 | |
| 82 | static struct tmp102 *tmp102_update_device(struct device *dev) |
| 83 | { |
| 84 | struct tmp102 *tmp102 = dev_get_drvdata(dev); |
| 85 | struct i2c_client *client = tmp102->client; |
| 86 | |
| 87 | mutex_lock(&tmp102->lock); |
| 88 | if (time_after(jiffies, tmp102->last_update + HZ / 3)) { |
| 89 | int i; |
| 90 | for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) { |
| 91 | int status = i2c_smbus_read_word_swapped(client, |
| 92 | tmp102_reg[i]); |
| 93 | if (status > -1) |
| 94 | tmp102->temp[i] = tmp102_reg_to_mC(status); |
| 95 | } |
| 96 | tmp102->last_update = jiffies; |
| 97 | tmp102->first_time = false; |
| 98 | } |
| 99 | mutex_unlock(&tmp102->lock); |
| 100 | return tmp102; |
| 101 | } |
| 102 | |
| 103 | static int tmp102_read_temp(void *dev, int *temp) |
| 104 | { |
| 105 | struct tmp102 *tmp102 = tmp102_update_device(dev); |
| 106 | |
| 107 | /* Is it too early even to return a conversion? */ |
| 108 | if (tmp102->first_time) { |
| 109 | dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); |
| 110 | return -EAGAIN; |
| 111 | } |
| 112 | |
| 113 | *temp = tmp102->temp[0]; |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static ssize_t tmp102_show_temp(struct device *dev, |
| 119 | struct device_attribute *attr, |
| 120 | char *buf) |
| 121 | { |
| 122 | struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); |
| 123 | struct tmp102 *tmp102 = tmp102_update_device(dev); |
| 124 | |
| 125 | /* Is it too early even to return a read? */ |
| 126 | if (tmp102->first_time) |
| 127 | return -EAGAIN; |
| 128 | |
| 129 | return sprintf(buf, "%d\n", tmp102->temp[sda->index]); |
| 130 | } |
| 131 | |
| 132 | static ssize_t tmp102_set_temp(struct device *dev, |
| 133 | struct device_attribute *attr, |
| 134 | const char *buf, size_t count) |
| 135 | { |
| 136 | struct sensor_device_attribute *sda = to_sensor_dev_attr(attr); |
| 137 | struct tmp102 *tmp102 = dev_get_drvdata(dev); |
| 138 | struct i2c_client *client = tmp102->client; |
| 139 | long val; |
| 140 | int status; |
| 141 | |
| 142 | if (kstrtol(buf, 10, &val) < 0) |
| 143 | return -EINVAL; |
| 144 | val = clamp_val(val, -256000, 255000); |
| 145 | |
| 146 | mutex_lock(&tmp102->lock); |
| 147 | tmp102->temp[sda->index] = val; |
| 148 | status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index], |
| 149 | tmp102_mC_to_reg(val)); |
| 150 | mutex_unlock(&tmp102->lock); |
| 151 | return status ? : count; |
| 152 | } |
| 153 | |
| 154 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0); |
| 155 | |
| 156 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp, |
| 157 | tmp102_set_temp, 1); |
| 158 | |
| 159 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp, |
| 160 | tmp102_set_temp, 2); |
| 161 | |
| 162 | static struct attribute *tmp102_attrs[] = { |
| 163 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
| 164 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, |
| 165 | &sensor_dev_attr_temp1_max.dev_attr.attr, |
| 166 | NULL |
| 167 | }; |
| 168 | ATTRIBUTE_GROUPS(tmp102); |
| 169 | |
| 170 | #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1) |
| 171 | #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL) |
| 172 | |
| 173 | static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { |
| 174 | .get_temp = tmp102_read_temp, |
| 175 | }; |
| 176 | |
| 177 | static int tmp102_probe(struct i2c_client *client, |
| 178 | const struct i2c_device_id *id) |
| 179 | { |
| 180 | struct device *dev = &client->dev; |
| 181 | struct device *hwmon_dev; |
| 182 | struct tmp102 *tmp102; |
| 183 | int status; |
| 184 | |
| 185 | if (!i2c_check_functionality(client->adapter, |
| 186 | I2C_FUNC_SMBUS_WORD_DATA)) { |
| 187 | dev_err(dev, |
| 188 | "adapter doesn't support SMBus word transactions\n"); |
| 189 | return -ENODEV; |
| 190 | } |
| 191 | |
| 192 | tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); |
| 193 | if (!tmp102) |
| 194 | return -ENOMEM; |
| 195 | |
| 196 | i2c_set_clientdata(client, tmp102); |
| 197 | tmp102->client = client; |
| 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 | return status; |
| 203 | } |
| 204 | tmp102->config_orig = status; |
| 205 | status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, |
| 206 | TMP102_CONFIG); |
| 207 | if (status < 0) { |
| 208 | dev_err(dev, "error writing config register\n"); |
| 209 | goto fail_restore_config; |
| 210 | } |
| 211 | status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); |
| 212 | if (status < 0) { |
| 213 | dev_err(dev, "error reading config register\n"); |
| 214 | goto fail_restore_config; |
| 215 | } |
| 216 | status &= ~TMP102_CONFIG_RD_ONLY; |
| 217 | if (status != TMP102_CONFIG) { |
| 218 | dev_err(dev, "config settings did not stick\n"); |
| 219 | status = -ENODEV; |
| 220 | goto fail_restore_config; |
| 221 | } |
| 222 | tmp102->last_update = jiffies; |
| 223 | /* Mark that we are not ready with data until conversion is complete */ |
| 224 | tmp102->first_time = true; |
| 225 | mutex_init(&tmp102->lock); |
| 226 | |
| 227 | hwmon_dev = hwmon_device_register_with_groups(dev, client->name, |
| 228 | tmp102, tmp102_groups); |
| 229 | if (IS_ERR(hwmon_dev)) { |
| 230 | dev_dbg(dev, "unable to register hwmon device\n"); |
| 231 | status = PTR_ERR(hwmon_dev); |
| 232 | goto fail_restore_config; |
| 233 | } |
| 234 | tmp102->hwmon_dev = hwmon_dev; |
| 235 | tmp102->tz = thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev, |
| 236 | &tmp102_of_thermal_ops); |
| 237 | if (IS_ERR(tmp102->tz)) |
| 238 | tmp102->tz = NULL; |
| 239 | |
| 240 | dev_info(dev, "initialized\n"); |
| 241 | |
| 242 | return 0; |
| 243 | |
| 244 | fail_restore_config: |
| 245 | i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, |
| 246 | tmp102->config_orig); |
| 247 | return status; |
| 248 | } |
| 249 | |
| 250 | static int tmp102_remove(struct i2c_client *client) |
| 251 | { |
| 252 | struct tmp102 *tmp102 = i2c_get_clientdata(client); |
| 253 | |
| 254 | thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz); |
| 255 | hwmon_device_unregister(tmp102->hwmon_dev); |
| 256 | |
| 257 | /* Stop monitoring if device was stopped originally */ |
| 258 | if (tmp102->config_orig & TMP102_CONF_SD) { |
| 259 | int config; |
| 260 | |
| 261 | config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); |
| 262 | if (config >= 0) |
| 263 | i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, |
| 264 | config | TMP102_CONF_SD); |
| 265 | } |
| 266 | |
| 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | #ifdef CONFIG_PM_SLEEP |
| 271 | static int tmp102_suspend(struct device *dev) |
| 272 | { |
| 273 | struct i2c_client *client = to_i2c_client(dev); |
| 274 | int config; |
| 275 | |
| 276 | config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); |
| 277 | if (config < 0) |
| 278 | return config; |
| 279 | |
| 280 | config |= TMP102_CONF_SD; |
| 281 | return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); |
| 282 | } |
| 283 | |
| 284 | static int tmp102_resume(struct device *dev) |
| 285 | { |
| 286 | struct i2c_client *client = to_i2c_client(dev); |
| 287 | int config; |
| 288 | |
| 289 | config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG); |
| 290 | if (config < 0) |
| 291 | return config; |
| 292 | |
| 293 | config &= ~TMP102_CONF_SD; |
| 294 | return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config); |
| 295 | } |
| 296 | #endif /* CONFIG_PM */ |
| 297 | |
| 298 | static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); |
| 299 | |
| 300 | static const struct i2c_device_id tmp102_id[] = { |
| 301 | { "tmp102", 0 }, |
| 302 | { } |
| 303 | }; |
| 304 | MODULE_DEVICE_TABLE(i2c, tmp102_id); |
| 305 | |
| 306 | static struct i2c_driver tmp102_driver = { |
| 307 | .driver.name = DRIVER_NAME, |
| 308 | .driver.pm = &tmp102_dev_pm_ops, |
| 309 | .probe = tmp102_probe, |
| 310 | .remove = tmp102_remove, |
| 311 | .id_table = tmp102_id, |
| 312 | }; |
| 313 | |
| 314 | module_i2c_driver(tmp102_driver); |
| 315 | |
| 316 | MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); |
| 317 | MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); |
| 318 | MODULE_LICENSE("GPL"); |