blob: e4def62c0ebf4fbfcacdbdf2e1c605b17dacda02 [file] [log] [blame]
Steven Kingbeb1b6b2010-05-27 19:58:56 +02001/* Texas Instruments TMP102 SMBUS temperature sensor driver
2 *
3 * Copyright 2010 Steven King <sfking@fdwdc.com>
4 *
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
20
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/i2c.h>
26#include <linux/hwmon.h>
27#include <linux/hwmon-sysfs.h>
28#include <linux/err.h>
29#include <linux/mutex.h>
30#include <linux/delay.h>
31
32#define DRIVER_NAME "tmp102"
33
34#define TMP102_TEMP_REG 0x00
35#define TMP102_CONF_REG 0x01
36/* note: these bit definitions are byte swapped */
37#define TMP102_CONF_SD 0x0100
38#define TMP102_CONF_TM 0x0200
39#define TMP102_CONF_POL 0x0400
40#define TMP102_CONF_F0 0x0800
41#define TMP102_CONF_F1 0x1000
42#define TMP102_CONF_R0 0x2000
43#define TMP102_CONF_R1 0x4000
44#define TMP102_CONF_OS 0x8000
45#define TMP102_CONF_EM 0x0010
46#define TMP102_CONF_AL 0x0020
47#define TMP102_CONF_CR0 0x0040
48#define TMP102_CONF_CR1 0x0080
49#define TMP102_TLOW_REG 0x02
50#define TMP102_THIGH_REG 0x03
51
52struct tmp102 {
53 struct device *hwmon_dev;
54 struct mutex lock;
55 unsigned long last_update;
56 int temp[3];
57};
58
59/* the TMP102 registers are big endian so we have to swab16 the values */
60static int tmp102_read_reg(struct i2c_client *client, u8 reg)
61{
62 int result = i2c_smbus_read_word_data(client, reg);
63 return result < 0 ? result : swab16(result);
64}
65
66static int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
67{
68 return i2c_smbus_write_word_data(client, reg, swab16(val));
69}
70
71/* convert left adjusted 13bit TMP102 register value to miliCelsius */
72static int tmp102_reg_to_mC(s16 val)
73{
74 return (val * 1000) / 128;
75}
76
77/* convert miliCelsius to left adjusted 13bit TMP102 register value */
78static u16 tmp102_mC_to_reg(int val)
79{
80 return (val * 128) / 1000;
81}
82
83static const u8 tmp102_reg[] = {
84 TMP102_TEMP_REG,
85 TMP102_TLOW_REG,
86 TMP102_THIGH_REG,
87};
88
89static struct tmp102 *tmp102_update_device(struct i2c_client *client)
90{
91 struct tmp102 *tmp102 = i2c_get_clientdata(client);
92
93 mutex_lock(&tmp102->lock);
94 if (time_after(jiffies, tmp102->last_update + HZ / 4)) {
95 int i;
96 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
97 int status = tmp102_read_reg(client, tmp102_reg[i]);
98 if (status > -1)
99 tmp102->temp[i] = tmp102_reg_to_mC(status);
100 }
101 tmp102->last_update = jiffies;
102 }
103 mutex_unlock(&tmp102->lock);
104 return tmp102;
105}
106
107static ssize_t tmp102_show_temp(struct device *dev,
108 struct device_attribute *attr,
109 char *buf)
110{
111 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
112 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
113
114 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
115}
116
117static ssize_t tmp102_set_temp(struct device *dev,
118 struct device_attribute *attr,
119 const char *buf, size_t count)
120{
121 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
122 struct i2c_client *client = to_i2c_client(dev);
123 struct tmp102 *tmp102 = i2c_get_clientdata(client);
124 long val;
125 int status = 0;
126
127 if ((strict_strtol(buf, 10, &val) < 0) || (abs(val) > 150000))
128 return -EINVAL;
129 mutex_lock(&tmp102->lock);
130 if (tmp102->temp[sda->index] != val) {
131 tmp102->temp[sda->index] = val;
132 status = tmp102_write_reg(client, tmp102_reg[sda->index],
133 tmp102_mC_to_reg(val));
134 }
135 mutex_unlock(&tmp102->lock);
136 return status ? : count;
137}
138
139static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
140
141static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
142 tmp102_set_temp, 1);
143
144static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
145 tmp102_set_temp, 2);
146
147static struct attribute *tmp102_attributes[] = {
148 &sensor_dev_attr_temp1_input.dev_attr.attr,
149 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
150 &sensor_dev_attr_temp1_max.dev_attr.attr,
151 NULL
152};
153
154static const struct attribute_group tmp102_attr_group = {
155 .attrs = tmp102_attributes,
156};
157
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)
160
161static int __devinit tmp102_probe(struct i2c_client *client,
162 const struct i2c_device_id *id)
163{
164 struct tmp102 *tmp102;
165 int status;
166
167 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
168 I2C_FUNC_SMBUS_WORD_DATA)) {
169 dev_dbg(&client->dev, "adapter doesnt support SMBUS\n");
170 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
180 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
181 status = tmp102_read_reg(client, TMP102_CONF_REG);
182 if (status < 0) {
183 dev_dbg(&client->dev, "error reading config register\n");
184 goto fail0;
185 }
186 status &= ~TMP102_CONFIG_RD_ONLY;
187 if (status != TMP102_CONFIG) {
188 dev_dbg(&client->dev, "could not verify config settings\n");
189 status = -EIO;
190 goto fail0;
191 }
192 tmp102->last_update = jiffies - HZ;
193 mutex_init(&tmp102->lock);
194
195 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
196 if (status) {
197 dev_dbg(&client->dev, "could not create sysfs files\n");
198 goto fail0;
199 }
200 tmp102->hwmon_dev = hwmon_device_register(&client->dev);
201 if (IS_ERR(tmp102->hwmon_dev)) {
202 dev_dbg(&client->dev, "unable to register hwmon device\n");
203 status = PTR_ERR(tmp102->hwmon_dev);
204 goto fail1;
205 }
206
207 dev_info(&client->dev, "initialized\n");
208
209 return 0;
210fail1:
211 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
212fail0:
213 i2c_set_clientdata(client, NULL);
214 kfree(tmp102);
215
216 return 0;
217}
218
219static int __devexit tmp102_remove(struct i2c_client *client)
220{
221 struct tmp102 *tmp102 = i2c_get_clientdata(client);
222
223 /* shutdown the chip */
224 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
225
226 hwmon_device_unregister(tmp102->hwmon_dev);
227 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
228 i2c_set_clientdata(client, NULL);
229 kfree(tmp102);
230
231 return 0;
232}
233
234#ifdef CONFIG_PM
235static int tmp102_suspend(struct device *dev)
236{
237 struct i2c_client *client = to_i2c_client(dev);
238
239 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONF_SD);
240
241 return 0;
242}
243
244static int tmp102_resume(struct device *dev)
245{
246 struct i2c_client *client = to_i2c_client(dev);
247
248 tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
249
250 return 0;
251}
252
253static const struct dev_pm_ops tmp102_dev_pm_ops = {
254 .suspend = tmp102_suspend,
255 .resume = tmp102_resume,
256};
257
258#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
259#else
260#define TMP102_DEV_PM_OPS NULL
261#endif /* CONFIG_PM */
262
263static const unsigned short normal_i2c[] = {
264 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END
265};
266
267static const struct i2c_device_id tmp102_id[] = {
268 { DRIVER_NAME, 0 },
269 { }
270};
271
272static struct i2c_driver tmp102_driver = {
273 .driver.name = DRIVER_NAME,
274 .driver.pm = TMP102_DEV_PM_OPS,
275 .class = I2C_CLASS_HWMON,
276 .probe = tmp102_probe,
277 .remove = __devexit_p(tmp102_remove),
278 .id_table = tmp102_id,
279 .address_list = normal_i2c,
280};
281
282static int __init tmp102_init(void)
283{
284 return i2c_add_driver(&tmp102_driver);
285}
286module_init(tmp102_init);
287
288static void __exit tmp102_exit(void)
289{
290 i2c_del_driver(&tmp102_driver);
291}
292module_exit(tmp102_exit);
293
294
295MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
296MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
297MODULE_LICENSE("GPL");