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>
30 #define DRIVER_NAME "tmp102"
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
51 struct device *hwmon_dev;
54 unsigned long last_update;
58 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
59 static inline int tmp102_reg_to_mC(s16 val)
61 return ((val & ~0x01) * 1000) / 128;
64 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
65 static inline u16 tmp102_mC_to_reg(int val)
67 return (val * 128) / 1000;
70 static const u8 tmp102_reg[] = {
76 static struct tmp102 *tmp102_update_device(struct i2c_client *client)
78 struct tmp102 *tmp102 = i2c_get_clientdata(client);
80 mutex_lock(&tmp102->lock);
81 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
83 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
84 int status = i2c_smbus_read_word_swapped(client,
87 tmp102->temp[i] = tmp102_reg_to_mC(status);
89 tmp102->last_update = jiffies;
91 mutex_unlock(&tmp102->lock);
95 static ssize_t tmp102_show_temp(struct device *dev,
96 struct device_attribute *attr,
99 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
100 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
102 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
105 static ssize_t tmp102_set_temp(struct device *dev,
106 struct device_attribute *attr,
107 const char *buf, size_t count)
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);
115 if (kstrtol(buf, 10, &val) < 0)
117 val = SENSORS_LIMIT(val, -256000, 255000);
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;
127 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
129 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
132 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
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,
142 static const struct attribute_group tmp102_attr_group = {
143 .attrs = tmp102_attributes,
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)
149 static int __devinit tmp102_probe(struct i2c_client *client,
150 const struct i2c_device_id *id)
152 struct tmp102 *tmp102;
155 if (!i2c_check_functionality(client->adapter,
156 I2C_FUNC_SMBUS_WORD_DATA)) {
157 dev_err(&client->dev, "adapter doesn't support SMBus word "
162 tmp102 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL);
166 i2c_set_clientdata(client, tmp102);
168 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
170 dev_err(&client->dev, "error reading config register\n");
173 tmp102->config_orig = status;
174 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
177 dev_err(&client->dev, "error writing config register\n");
178 goto fail_restore_config;
180 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
182 dev_err(&client->dev, "error reading config register\n");
183 goto fail_restore_config;
185 status &= ~TMP102_CONFIG_RD_ONLY;
186 if (status != TMP102_CONFIG) {
187 dev_err(&client->dev, "config settings did not stick\n");
189 goto fail_restore_config;
191 tmp102->last_update = jiffies - HZ;
192 mutex_init(&tmp102->lock);
194 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
196 dev_dbg(&client->dev, "could not create sysfs files\n");
197 goto fail_restore_config;
199 tmp102->hwmon_dev = hwmon_device_register(&client->dev);
200 if (IS_ERR(tmp102->hwmon_dev)) {
201 dev_dbg(&client->dev, "unable to register hwmon device\n");
202 status = PTR_ERR(tmp102->hwmon_dev);
203 goto fail_remove_sysfs;
206 dev_info(&client->dev, "initialized\n");
211 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
213 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
214 tmp102->config_orig);
218 static int __devexit tmp102_remove(struct i2c_client *client)
220 struct tmp102 *tmp102 = i2c_get_clientdata(client);
222 hwmon_device_unregister(tmp102->hwmon_dev);
223 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
225 /* Stop monitoring if device was stopped originally */
226 if (tmp102->config_orig & TMP102_CONF_SD) {
229 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
231 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
232 config | TMP102_CONF_SD);
239 static int tmp102_suspend(struct device *dev)
241 struct i2c_client *client = to_i2c_client(dev);
244 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
248 config |= TMP102_CONF_SD;
249 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
252 static int tmp102_resume(struct device *dev)
254 struct i2c_client *client = to_i2c_client(dev);
257 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
261 config &= ~TMP102_CONF_SD;
262 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
265 static const struct dev_pm_ops tmp102_dev_pm_ops = {
266 .suspend = tmp102_suspend,
267 .resume = tmp102_resume,
270 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
272 #define TMP102_DEV_PM_OPS NULL
273 #endif /* CONFIG_PM */
275 static const struct i2c_device_id tmp102_id[] = {
279 MODULE_DEVICE_TABLE(i2c, tmp102_id);
281 static struct i2c_driver tmp102_driver = {
282 .driver.name = DRIVER_NAME,
283 .driver.pm = TMP102_DEV_PM_OPS,
284 .probe = tmp102_probe,
285 .remove = __devexit_p(tmp102_remove),
286 .id_table = tmp102_id,
289 module_i2c_driver(tmp102_driver);
291 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
292 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
293 MODULE_LICENSE("GPL");