1 /* Texas Instruments TMP102 SMBus temperature sensor driver
3 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
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.
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.
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
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>
33 #define DRIVER_NAME "tmp102"
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
54 struct i2c_client *client;
55 struct device *hwmon_dev;
56 struct thermal_zone_device *tz;
59 unsigned long last_update;
63 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
64 static inline int tmp102_reg_to_mC(s16 val)
66 return ((val & ~0x01) * 1000) / 128;
69 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
70 static inline u16 tmp102_mC_to_reg(int val)
72 return (val * 128) / 1000;
75 static const u8 tmp102_reg[] = {
81 static struct tmp102 *tmp102_update_device(struct device *dev)
83 struct tmp102 *tmp102 = dev_get_drvdata(dev);
84 struct i2c_client *client = tmp102->client;
86 mutex_lock(&tmp102->lock);
87 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
89 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
90 int status = i2c_smbus_read_word_swapped(client,
93 tmp102->temp[i] = tmp102_reg_to_mC(status);
95 tmp102->last_update = jiffies;
97 mutex_unlock(&tmp102->lock);
101 static int tmp102_read_temp(void *dev, int *temp)
103 struct tmp102 *tmp102 = tmp102_update_device(dev);
105 *temp = tmp102->temp[0];
110 static ssize_t tmp102_show_temp(struct device *dev,
111 struct device_attribute *attr,
114 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
115 struct tmp102 *tmp102 = tmp102_update_device(dev);
117 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
120 static ssize_t tmp102_set_temp(struct device *dev,
121 struct device_attribute *attr,
122 const char *buf, size_t count)
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;
130 if (kstrtol(buf, 10, &val) < 0)
132 val = clamp_val(val, -256000, 255000);
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;
142 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
144 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
147 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
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,
156 ATTRIBUTE_GROUPS(tmp102);
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)
161 static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = {
162 .get_temp = tmp102_read_temp,
165 static int tmp102_probe(struct i2c_client *client,
166 const struct i2c_device_id *id)
168 struct device *dev = &client->dev;
169 struct device *hwmon_dev;
170 struct tmp102 *tmp102;
173 if (!i2c_check_functionality(client->adapter,
174 I2C_FUNC_SMBUS_WORD_DATA)) {
176 "adapter doesn't support SMBus word transactions\n");
180 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
184 i2c_set_clientdata(client, tmp102);
185 tmp102->client = client;
187 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
189 dev_err(dev, "error reading config register\n");
192 tmp102->config_orig = status;
193 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
196 dev_err(dev, "error writing config register\n");
197 goto fail_restore_config;
199 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
201 dev_err(dev, "error reading config register\n");
202 goto fail_restore_config;
204 status &= ~TMP102_CONFIG_RD_ONLY;
205 if (status != TMP102_CONFIG) {
206 dev_err(dev, "config settings did not stick\n");
208 goto fail_restore_config;
210 tmp102->last_update = jiffies - HZ;
211 mutex_init(&tmp102->lock);
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;
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))
226 dev_info(dev, "initialized\n");
231 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
232 tmp102->config_orig);
236 static int tmp102_remove(struct i2c_client *client)
238 struct tmp102 *tmp102 = i2c_get_clientdata(client);
240 thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz);
241 hwmon_device_unregister(tmp102->hwmon_dev);
243 /* Stop monitoring if device was stopped originally */
244 if (tmp102->config_orig & TMP102_CONF_SD) {
247 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
249 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
250 config | TMP102_CONF_SD);
256 #ifdef CONFIG_PM_SLEEP
257 static int tmp102_suspend(struct device *dev)
259 struct i2c_client *client = to_i2c_client(dev);
262 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
266 config |= TMP102_CONF_SD;
267 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
270 static int tmp102_resume(struct device *dev)
272 struct i2c_client *client = to_i2c_client(dev);
275 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
279 config &= ~TMP102_CONF_SD;
280 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
282 #endif /* CONFIG_PM */
284 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
286 static const struct i2c_device_id tmp102_id[] = {
290 MODULE_DEVICE_TABLE(i2c, tmp102_id);
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,
300 module_i2c_driver(tmp102_driver);
302 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
303 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
304 MODULE_LICENSE("GPL");