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;
53 unsigned long last_update;
57 /* SMBus specifies low byte first, but the TMP102 returns high byte first,
58 * so we have to swab16 the values */
59 static inline int tmp102_read_reg(struct i2c_client *client, u8 reg)
61 int result = i2c_smbus_read_word_data(client, reg);
62 return result < 0 ? result : swab16(result);
65 static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
67 return i2c_smbus_write_word_data(client, reg, swab16(val));
70 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
71 static inline int tmp102_reg_to_mC(s16 val)
73 return ((val & ~0x01) * 1000) / 128;
76 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
77 static inline u16 tmp102_mC_to_reg(int val)
79 return (val * 128) / 1000;
82 static const u8 tmp102_reg[] = {
88 static struct tmp102 *tmp102_update_device(struct i2c_client *client)
90 struct tmp102 *tmp102 = i2c_get_clientdata(client);
92 mutex_lock(&tmp102->lock);
93 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
95 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
96 int status = tmp102_read_reg(client, tmp102_reg[i]);
98 tmp102->temp[i] = tmp102_reg_to_mC(status);
100 tmp102->last_update = jiffies;
102 mutex_unlock(&tmp102->lock);
106 static ssize_t tmp102_show_temp(struct device *dev,
107 struct device_attribute *attr,
110 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
111 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
113 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
116 static ssize_t tmp102_set_temp(struct device *dev,
117 struct device_attribute *attr,
118 const char *buf, size_t count)
120 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
121 struct i2c_client *client = to_i2c_client(dev);
122 struct tmp102 *tmp102 = i2c_get_clientdata(client);
126 if (strict_strtol(buf, 10, &val) < 0)
128 val = SENSORS_LIMIT(val, -256000, 255000);
130 mutex_lock(&tmp102->lock);
131 tmp102->temp[sda->index] = val;
132 status = tmp102_write_reg(client, tmp102_reg[sda->index],
133 tmp102_mC_to_reg(val));
134 mutex_unlock(&tmp102->lock);
135 return status ? : count;
138 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
140 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
143 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
146 static struct attribute *tmp102_attributes[] = {
147 &sensor_dev_attr_temp1_input.dev_attr.attr,
148 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
149 &sensor_dev_attr_temp1_max.dev_attr.attr,
153 static const struct attribute_group tmp102_attr_group = {
154 .attrs = tmp102_attributes,
157 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
158 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
160 static int __devinit tmp102_probe(struct i2c_client *client,
161 const struct i2c_device_id *id)
163 struct tmp102 *tmp102;
166 if (!i2c_check_functionality(client->adapter,
167 I2C_FUNC_SMBUS_WORD_DATA)) {
168 dev_err(&client->dev, "adapter doesnt support SMBus word "
173 tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL);
175 dev_dbg(&client->dev, "kzalloc failed\n");
178 i2c_set_clientdata(client, tmp102);
180 status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
182 dev_err(&client->dev, "error writing config register\n");
185 status = tmp102_read_reg(client, TMP102_CONF_REG);
187 dev_err(&client->dev, "error reading config register\n");
190 status &= ~TMP102_CONFIG_RD_ONLY;
191 if (status != TMP102_CONFIG) {
192 dev_err(&client->dev, "config settings did not stick\n");
196 tmp102->last_update = jiffies - HZ;
197 mutex_init(&tmp102->lock);
199 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
201 dev_dbg(&client->dev, "could not create sysfs files\n");
204 tmp102->hwmon_dev = hwmon_device_register(&client->dev);
205 if (IS_ERR(tmp102->hwmon_dev)) {
206 dev_dbg(&client->dev, "unable to register hwmon device\n");
207 status = PTR_ERR(tmp102->hwmon_dev);
211 dev_info(&client->dev, "initialized\n");
215 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
217 i2c_set_clientdata(client, NULL);
223 static int __devexit tmp102_remove(struct i2c_client *client)
225 struct tmp102 *tmp102 = i2c_get_clientdata(client);
227 /* shutdown the chip */
228 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
230 hwmon_device_unregister(tmp102->hwmon_dev);
231 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
232 i2c_set_clientdata(client, NULL);
239 static int tmp102_suspend(struct device *dev)
241 struct i2c_client *client = to_i2c_client(dev);
243 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
248 static int tmp102_resume(struct device *dev)
250 struct i2c_client *client = to_i2c_client(dev);
252 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
257 static const struct dev_pm_ops tmp102_dev_pm_ops = {
258 .suspend = tmp102_suspend,
259 .resume = tmp102_resume,
262 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
264 #define TMP102_DEV_PM_OPS NULL
265 #endif /* CONFIG_PM */
267 static const struct i2c_device_id tmp102_id[] = {
271 MODULE_DEVICE_TABLE(i2c, tmp102_id);
273 static struct i2c_driver tmp102_driver = {
274 .driver.name = DRIVER_NAME,
275 .driver.pm = TMP102_DEV_PM_OPS,
276 .probe = tmp102_probe,
277 .remove = __devexit_p(tmp102_remove),
278 .id_table = tmp102_id,
281 static int __init tmp102_init(void)
283 return i2c_add_driver(&tmp102_driver);
285 module_init(tmp102_init);
287 static void __exit tmp102_exit(void)
289 i2c_del_driver(&tmp102_driver);
291 module_exit(tmp102_exit);
293 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
294 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
295 MODULE_LICENSE("GPL");