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Jean Delvarecff37c92010-05-27 19:58:57 +02001/* Texas Instruments TMP102 SMBus temperature sensor driver
Steven Kingbeb1b6b2010-05-27 19:58:56 +02002 *
Jean Delvarecff37c92010-05-27 19:58:57 +02003 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
Steven Kingbeb1b6b2010-05-27 19:58:56 +02004 *
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
Steven Kingbeb1b6b2010-05-27 19:58:56 +020020#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>
Jean Delvarecff37c92010-05-27 19:58:57 +020028#include <linux/device.h>
Steven Kingbeb1b6b2010-05-27 19:58:56 +020029
30#define DRIVER_NAME "tmp102"
31
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
49
50struct tmp102 {
51 struct device *hwmon_dev;
52 struct mutex lock;
53 unsigned long last_update;
54 int temp[3];
55};
56
Jean Delvarecff37c92010-05-27 19:58:57 +020057/* SMBus specifies low byte first, but the TMP102 returns high byte first,
58 * so we have to swab16 the values */
59static inline int tmp102_read_reg(struct i2c_client *client, u8 reg)
Steven Kingbeb1b6b2010-05-27 19:58:56 +020060{
61 int result = i2c_smbus_read_word_data(client, reg);
62 return result < 0 ? result : swab16(result);
63}
64
Jean Delvarecff37c92010-05-27 19:58:57 +020065static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
Steven Kingbeb1b6b2010-05-27 19:58:56 +020066{
67 return i2c_smbus_write_word_data(client, reg, swab16(val));
68}
69
Jean Delvarecff37c92010-05-27 19:58:57 +020070/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
71static inline int tmp102_reg_to_mC(s16 val)
Steven Kingbeb1b6b2010-05-27 19:58:56 +020072{
Jean Delvarecff37c92010-05-27 19:58:57 +020073 return ((val & ~0x01) * 1000) / 128;
Steven Kingbeb1b6b2010-05-27 19:58:56 +020074}
75
Jean Delvarecff37c92010-05-27 19:58:57 +020076/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
77static inline u16 tmp102_mC_to_reg(int val)
Steven Kingbeb1b6b2010-05-27 19:58:56 +020078{
79 return (val * 128) / 1000;
80}
81
82static const u8 tmp102_reg[] = {
83 TMP102_TEMP_REG,
84 TMP102_TLOW_REG,
85 TMP102_THIGH_REG,
86};
87
88static struct tmp102 *tmp102_update_device(struct i2c_client *client)
89{
90 struct tmp102 *tmp102 = i2c_get_clientdata(client);
91
92 mutex_lock(&tmp102->lock);
Jean Delvarecff37c92010-05-27 19:58:57 +020093 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
Steven Kingbeb1b6b2010-05-27 19:58:56 +020094 int i;
95 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
96 int status = tmp102_read_reg(client, tmp102_reg[i]);
97 if (status > -1)
98 tmp102->temp[i] = tmp102_reg_to_mC(status);
99 }
100 tmp102->last_update = jiffies;
101 }
102 mutex_unlock(&tmp102->lock);
103 return tmp102;
104}
105
106static ssize_t tmp102_show_temp(struct device *dev,
107 struct device_attribute *attr,
108 char *buf)
109{
110 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
111 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
112
113 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
114}
115
116static ssize_t tmp102_set_temp(struct device *dev,
117 struct device_attribute *attr,
118 const char *buf, size_t count)
119{
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);
123 long val;
Jean Delvarecff37c92010-05-27 19:58:57 +0200124 int status;
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200125
Jean Delvarecff37c92010-05-27 19:58:57 +0200126 if (strict_strtol(buf, 10, &val) < 0)
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200127 return -EINVAL;
Jean Delvarecff37c92010-05-27 19:58:57 +0200128 val = SENSORS_LIMIT(val, -256000, 255000);
129
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200130 mutex_lock(&tmp102->lock);
Jean Delvarecff37c92010-05-27 19:58:57 +0200131 tmp102->temp[sda->index] = val;
132 status = tmp102_write_reg(client, tmp102_reg[sda->index],
133 tmp102_mC_to_reg(val));
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200134 mutex_unlock(&tmp102->lock);
135 return status ? : count;
136}
137
138static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
139
140static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
141 tmp102_set_temp, 1);
142
143static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
144 tmp102_set_temp, 2);
145
146static 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,
150 NULL
151};
152
153static const struct attribute_group tmp102_attr_group = {
154 .attrs = tmp102_attributes,
155};
156
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)
159
160static int __devinit tmp102_probe(struct i2c_client *client,
161 const struct i2c_device_id *id)
162{
163 struct tmp102 *tmp102;
164 int status;
165
Jean Delvarecff37c92010-05-27 19:58:57 +0200166 if (!i2c_check_functionality(client->adapter,
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200167 I2C_FUNC_SMBUS_WORD_DATA)) {
Jean Delvarecff37c92010-05-27 19:58:57 +0200168 dev_err(&client->dev, "adapter doesnt support SMBus word "
169 "transactions\n");
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200170 return -ENODEV;
171 }
172
173 tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL);
174 if (!tmp102) {
175 dev_dbg(&client->dev, "kzalloc failed\n");
176 return -ENOMEM;
177 }
178 i2c_set_clientdata(client, tmp102);
179
Jean Delvarecff37c92010-05-27 19:58:57 +0200180 status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
181 if (status < 0) {
182 dev_err(&client->dev, "error writing config register\n");
183 goto fail0;
184 }
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200185 status = tmp102_read_reg(client, TMP102_CONF_REG);
186 if (status < 0) {
Jean Delvarecff37c92010-05-27 19:58:57 +0200187 dev_err(&client->dev, "error reading config register\n");
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200188 goto fail0;
189 }
190 status &= ~TMP102_CONFIG_RD_ONLY;
191 if (status != TMP102_CONFIG) {
Jean Delvarecff37c92010-05-27 19:58:57 +0200192 dev_err(&client->dev, "config settings did not stick\n");
193 status = -ENODEV;
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200194 goto fail0;
195 }
196 tmp102->last_update = jiffies - HZ;
197 mutex_init(&tmp102->lock);
198
199 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
200 if (status) {
201 dev_dbg(&client->dev, "could not create sysfs files\n");
202 goto fail0;
203 }
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);
208 goto fail1;
209 }
210
211 dev_info(&client->dev, "initialized\n");
212
213 return 0;
214fail1:
215 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
216fail0:
217 i2c_set_clientdata(client, NULL);
218 kfree(tmp102);
219
Jean Delvarecff37c92010-05-27 19:58:57 +0200220 return status;
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200221}
222
223static int __devexit tmp102_remove(struct i2c_client *client)
224{
225 struct tmp102 *tmp102 = i2c_get_clientdata(client);
226
227 /* shutdown the chip */
228 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
229
230 hwmon_device_unregister(tmp102->hwmon_dev);
231 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
232 i2c_set_clientdata(client, NULL);
233 kfree(tmp102);
234
235 return 0;
236}
237
238#ifdef CONFIG_PM
239static int tmp102_suspend(struct device *dev)
240{
241 struct i2c_client *client = to_i2c_client(dev);
242
243 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
244
245 return 0;
246}
247
248static int tmp102_resume(struct device *dev)
249{
250 struct i2c_client *client = to_i2c_client(dev);
251
252 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
253
254 return 0;
255}
256
257static const struct dev_pm_ops tmp102_dev_pm_ops = {
258 .suspend = tmp102_suspend,
259 .resume = tmp102_resume,
260};
261
262#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
263#else
264#define TMP102_DEV_PM_OPS NULL
265#endif /* CONFIG_PM */
266
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200267static const struct i2c_device_id tmp102_id[] = {
Jean Delvarecff37c92010-05-27 19:58:57 +0200268 { "tmp102", 0 },
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200269 { }
270};
Jean Delvarecff37c92010-05-27 19:58:57 +0200271MODULE_DEVICE_TABLE(i2c, tmp102_id);
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200272
273static struct i2c_driver tmp102_driver = {
274 .driver.name = DRIVER_NAME,
275 .driver.pm = TMP102_DEV_PM_OPS,
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200276 .probe = tmp102_probe,
277 .remove = __devexit_p(tmp102_remove),
278 .id_table = tmp102_id,
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200279};
280
281static int __init tmp102_init(void)
282{
283 return i2c_add_driver(&tmp102_driver);
284}
285module_init(tmp102_init);
286
287static void __exit tmp102_exit(void)
288{
289 i2c_del_driver(&tmp102_driver);
290}
291module_exit(tmp102_exit);
292
Steven Kingbeb1b6b2010-05-27 19:58:56 +0200293MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
294MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
295MODULE_LICENSE("GPL");