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;
64 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
65 static inline int tmp102_reg_to_mC(s16 val)
67 return ((val & ~0x01) * 1000) / 128;
70 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
71 static inline u16 tmp102_mC_to_reg(int val)
73 return (val * 128) / 1000;
76 static const u8 tmp102_reg[] = {
82 static struct tmp102 *tmp102_update_device(struct device *dev)
84 struct tmp102 *tmp102 = dev_get_drvdata(dev);
85 struct i2c_client *client = tmp102->client;
87 mutex_lock(&tmp102->lock);
88 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
90 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
91 int status = i2c_smbus_read_word_swapped(client,
94 tmp102->temp[i] = tmp102_reg_to_mC(status);
96 tmp102->last_update = jiffies;
97 tmp102->first_time = false;
99 mutex_unlock(&tmp102->lock);
103 static int tmp102_read_temp(void *dev, int *temp)
105 struct tmp102 *tmp102 = tmp102_update_device(dev);
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__);
113 *temp = tmp102->temp[0];
118 static ssize_t tmp102_show_temp(struct device *dev,
119 struct device_attribute *attr,
122 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
123 struct tmp102 *tmp102 = tmp102_update_device(dev);
125 /* Is it too early even to return a read? */
126 if (tmp102->first_time)
129 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
132 static ssize_t tmp102_set_temp(struct device *dev,
133 struct device_attribute *attr,
134 const char *buf, size_t count)
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;
142 if (kstrtol(buf, 10, &val) < 0)
144 val = clamp_val(val, -256000, 255000);
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;
154 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
156 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
159 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
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,
168 ATTRIBUTE_GROUPS(tmp102);
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)
173 static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = {
174 .get_temp = tmp102_read_temp,
177 static int tmp102_probe(struct i2c_client *client,
178 const struct i2c_device_id *id)
180 struct device *dev = &client->dev;
181 struct device *hwmon_dev;
182 struct tmp102 *tmp102;
185 if (!i2c_check_functionality(client->adapter,
186 I2C_FUNC_SMBUS_WORD_DATA)) {
188 "adapter doesn't support SMBus word transactions\n");
192 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
196 i2c_set_clientdata(client, tmp102);
197 tmp102->client = client;
199 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
201 dev_err(dev, "error reading config register\n");
204 tmp102->config_orig = status;
205 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
208 dev_err(dev, "error writing config register\n");
209 goto fail_restore_config;
211 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
213 dev_err(dev, "error reading config register\n");
214 goto fail_restore_config;
216 status &= ~TMP102_CONFIG_RD_ONLY;
217 if (status != TMP102_CONFIG) {
218 dev_err(dev, "config settings did not stick\n");
220 goto fail_restore_config;
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);
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;
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))
240 dev_info(dev, "initialized\n");
245 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
246 tmp102->config_orig);
250 static int tmp102_remove(struct i2c_client *client)
252 struct tmp102 *tmp102 = i2c_get_clientdata(client);
254 thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz);
255 hwmon_device_unregister(tmp102->hwmon_dev);
257 /* Stop monitoring if device was stopped originally */
258 if (tmp102->config_orig & TMP102_CONF_SD) {
261 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
263 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
264 config | TMP102_CONF_SD);
270 #ifdef CONFIG_PM_SLEEP
271 static int tmp102_suspend(struct device *dev)
273 struct i2c_client *client = to_i2c_client(dev);
276 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
280 config |= TMP102_CONF_SD;
281 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
284 static int tmp102_resume(struct device *dev)
286 struct i2c_client *client = to_i2c_client(dev);
289 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
293 config &= ~TMP102_CONF_SD;
294 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
296 #endif /* CONFIG_PM */
298 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
300 static const struct i2c_device_id tmp102_id[] = {
304 MODULE_DEVICE_TABLE(i2c, tmp102_id);
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,
314 module_i2c_driver(tmp102_driver);
316 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
317 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
318 MODULE_LICENSE("GPL");