blob: f82acf67acf54c7180a35cd45b263615fc87a024 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Guenter Roeck02fe2fd2012-01-14 13:42:20 -08002 * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring
4 *
5 * Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
6 *
7 * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
8 * is a temperature sensor and thermal window comparator with 0.5 deg
9 * resolution made by National Semiconductor. Complete datasheet can be
10 * obtained at their site:
11 * http://www.national.com/pf/LM/LM77.html
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/jiffies.h>
32#include <linux/i2c.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040033#include <linux/hwmon.h>
Jean Delvare1f52af02008-01-03 23:35:33 +010034#include <linux/hwmon-sysfs.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040035#include <linux/err.h>
Ingo Molnar9a61bf62006-01-18 23:19:26 +010036#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38/* Addresses to scan */
Mark M. Hoffman25e9c862008-02-17 22:28:03 -050039static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
40 I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Linus Torvalds1da177e2005-04-16 15:20:36 -070042/* The LM77 registers */
43#define LM77_REG_TEMP 0x00
44#define LM77_REG_CONF 0x01
45#define LM77_REG_TEMP_HYST 0x02
46#define LM77_REG_TEMP_CRIT 0x03
47#define LM77_REG_TEMP_MIN 0x04
48#define LM77_REG_TEMP_MAX 0x05
49
50/* Each client has this additional data */
51struct lm77_data {
Guenter Roeck02fe2fd2012-01-14 13:42:20 -080052 struct device *hwmon_dev;
Ingo Molnar9a61bf62006-01-18 23:19:26 +010053 struct mutex update_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 char valid;
55 unsigned long last_updated; /* In jiffies */
56 int temp_input; /* Temperatures */
57 int temp_crit;
58 int temp_min;
59 int temp_max;
60 int temp_hyst;
61 u8 alarms;
62};
63
Jean Delvarea189dd62008-07-16 19:30:13 +020064static int lm77_probe(struct i2c_client *client,
65 const struct i2c_device_id *id);
Jean Delvare310ec792009-12-14 21:17:23 +010066static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067static void lm77_init_client(struct i2c_client *client);
Jean Delvarea189dd62008-07-16 19:30:13 +020068static int lm77_remove(struct i2c_client *client);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static u16 lm77_read_value(struct i2c_client *client, u8 reg);
70static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
71
72static struct lm77_data *lm77_update_device(struct device *dev);
73
74
Jean Delvarea189dd62008-07-16 19:30:13 +020075static const struct i2c_device_id lm77_id[] = {
Jean Delvare1f86df42009-12-14 21:17:26 +010076 { "lm77", 0 },
Jean Delvarea189dd62008-07-16 19:30:13 +020077 { }
78};
79MODULE_DEVICE_TABLE(i2c, lm77_id);
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081/* This is the driver that will be inserted */
82static struct i2c_driver lm77_driver = {
Jean Delvarea189dd62008-07-16 19:30:13 +020083 .class = I2C_CLASS_HWMON,
Laurent Riffardcdaf7932005-11-26 20:37:41 +010084 .driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010085 .name = "lm77",
86 },
Jean Delvarea189dd62008-07-16 19:30:13 +020087 .probe = lm77_probe,
88 .remove = lm77_remove,
89 .id_table = lm77_id,
90 .detect = lm77_detect,
Jean Delvarec3813d62009-12-14 21:17:25 +010091 .address_list = normal_i2c,
Linus Torvalds1da177e2005-04-16 15:20:36 -070092};
93
94/* straight from the datasheet */
95#define LM77_TEMP_MIN (-55000)
96#define LM77_TEMP_MAX 125000
97
Guenter Roeck02fe2fd2012-01-14 13:42:20 -080098/*
99 * In the temperature registers, the low 3 bits are not part of the
100 * temperature values; they are the status bits.
101 */
Jean Delvare413b6452006-01-09 22:43:08 +0100102static inline s16 LM77_TEMP_TO_REG(int temp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
104 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
Jean Delvare413b6452006-01-09 22:43:08 +0100105 return (ntemp / 500) * 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
107
Jean Delvare413b6452006-01-09 22:43:08 +0100108static inline int LM77_TEMP_FROM_REG(s16 reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
Jean Delvare413b6452006-01-09 22:43:08 +0100110 return (reg / 8) * 500;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
113/* sysfs stuff */
114
115/* read routines for temperature limits */
116#define show(value) \
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800117static ssize_t show_##value(struct device *dev, \
118 struct device_attribute *attr, \
119 char *buf) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{ \
121 struct lm77_data *data = lm77_update_device(dev); \
122 return sprintf(buf, "%d\n", data->value); \
123}
124
125show(temp_input);
126show(temp_crit);
127show(temp_min);
128show(temp_max);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
130/* read routines for hysteresis values */
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800131static ssize_t show_temp_crit_hyst(struct device *dev,
132 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133{
134 struct lm77_data *data = lm77_update_device(dev);
135 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
136}
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800137static ssize_t show_temp_min_hyst(struct device *dev,
138 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 struct lm77_data *data = lm77_update_device(dev);
141 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
142}
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800143static ssize_t show_temp_max_hyst(struct device *dev,
144 struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 struct lm77_data *data = lm77_update_device(dev);
147 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
148}
149
150/* write routines */
151#define set(value, reg) \
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800152static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
153 const char *buf, size_t count) \
154{ \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct lm77_data *data = i2c_get_clientdata(client); \
157 long val; \
158 int err = kstrtol(buf, 10, &val); \
159 if (err) \
160 return err; \
161 \
162 mutex_lock(&data->update_lock); \
163 data->value = val; \
164 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
165 mutex_unlock(&data->update_lock); \
166 return count; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167}
168
169set(temp_min, LM77_REG_TEMP_MIN);
170set(temp_max, LM77_REG_TEMP_MAX);
171
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800172/*
173 * hysteresis is stored as a relative value on the chip, so it has to be
174 * converted first
175 */
176static ssize_t set_temp_crit_hyst(struct device *dev,
177 struct device_attribute *attr,
178 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 struct i2c_client *client = to_i2c_client(dev);
181 struct lm77_data *data = i2c_get_clientdata(client);
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800182 unsigned long val;
183 int err;
184
185 err = kstrtoul(buf, 10, &val);
186 if (err)
187 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100189 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 data->temp_hyst = data->temp_crit - val;
191 lm77_write_value(client, LM77_REG_TEMP_HYST,
192 LM77_TEMP_TO_REG(data->temp_hyst));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100193 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 return count;
195}
196
197/* preserve hysteresis when setting T_crit */
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800198static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr,
199 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200{
201 struct i2c_client *client = to_i2c_client(dev);
202 struct lm77_data *data = i2c_get_clientdata(client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 int oldcrithyst;
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800204 unsigned long val;
205 int err;
206
207 err = kstrtoul(buf, 10, &val);
208 if (err)
209 return err;
210
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100211 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 oldcrithyst = data->temp_crit - data->temp_hyst;
213 data->temp_crit = val;
214 data->temp_hyst = data->temp_crit - oldcrithyst;
215 lm77_write_value(client, LM77_REG_TEMP_CRIT,
216 LM77_TEMP_TO_REG(data->temp_crit));
217 lm77_write_value(client, LM77_REG_TEMP_HYST,
218 LM77_TEMP_TO_REG(data->temp_hyst));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100219 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return count;
221}
222
Jean Delvare1f52af02008-01-03 23:35:33 +0100223static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
224 char *buf)
225{
226 int bitnr = to_sensor_dev_attr(attr)->index;
227 struct lm77_data *data = lm77_update_device(dev);
228 return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
229}
230
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231static DEVICE_ATTR(temp1_input, S_IRUGO,
232 show_temp_input, NULL);
233static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
234 show_temp_crit, set_temp_crit);
235static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
236 show_temp_min, set_temp_min);
237static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
238 show_temp_max, set_temp_max);
239
240static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
241 show_temp_crit_hyst, set_temp_crit_hyst);
242static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
243 show_temp_min_hyst, NULL);
244static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
245 show_temp_max_hyst, NULL);
246
Jean Delvare1f52af02008-01-03 23:35:33 +0100247static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
248static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
249static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200251static struct attribute *lm77_attributes[] = {
252 &dev_attr_temp1_input.attr,
253 &dev_attr_temp1_crit.attr,
254 &dev_attr_temp1_min.attr,
255 &dev_attr_temp1_max.attr,
256 &dev_attr_temp1_crit_hyst.attr,
257 &dev_attr_temp1_min_hyst.attr,
258 &dev_attr_temp1_max_hyst.attr,
Jean Delvare1f52af02008-01-03 23:35:33 +0100259 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
260 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
261 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200262 NULL
263};
264
265static const struct attribute_group lm77_group = {
266 .attrs = lm77_attributes,
267};
268
Jean Delvarea189dd62008-07-16 19:30:13 +0200269/* Return 0 if detection is successful, -ENODEV otherwise */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700270static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271{
Guenter Roeckefd2d112012-06-02 09:58:09 -0700272 struct i2c_adapter *adapter = client->adapter;
Jean Delvare747d9be2009-12-09 20:35:52 +0100273 int i, cur, conf, hyst, crit, min, max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
276 I2C_FUNC_SMBUS_WORD_DATA))
Jean Delvarea189dd62008-07-16 19:30:13 +0200277 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800279 /*
280 * Here comes the remaining detection. Since the LM77 has no
281 * register dedicated to identification, we have to rely on the
282 * following tricks:
283 *
284 * 1. the high 4 bits represent the sign and thus they should
285 * always be the same
286 * 2. the high 3 bits are unused in the configuration register
287 * 3. addresses 0x06 and 0x07 return the last read value
288 * 4. registers cycling over 8-address boundaries
289 *
290 * Word-sized registers are high-byte first.
291 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
Jean Delvare747d9be2009-12-09 20:35:52 +0100293 /* addresses cycling */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700294 cur = i2c_smbus_read_word_data(client, 0);
295 conf = i2c_smbus_read_byte_data(client, 1);
296 hyst = i2c_smbus_read_word_data(client, 2);
297 crit = i2c_smbus_read_word_data(client, 3);
298 min = i2c_smbus_read_word_data(client, 4);
299 max = i2c_smbus_read_word_data(client, 5);
Jean Delvare747d9be2009-12-09 20:35:52 +0100300 for (i = 8; i <= 0xff; i += 8) {
Guenter Roeckefd2d112012-06-02 09:58:09 -0700301 if (i2c_smbus_read_byte_data(client, i + 1) != conf
302 || i2c_smbus_read_word_data(client, i + 2) != hyst
303 || i2c_smbus_read_word_data(client, i + 3) != crit
304 || i2c_smbus_read_word_data(client, i + 4) != min
305 || i2c_smbus_read_word_data(client, i + 5) != max)
Jean Delvarea189dd62008-07-16 19:30:13 +0200306 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 }
308
Jean Delvare747d9be2009-12-09 20:35:52 +0100309 /* sign bits */
310 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
311 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
312 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
313 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
314 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
315 return -ENODEV;
316
317 /* unused bits */
318 if (conf & 0xe0)
319 return -ENODEV;
320
321 /* 0x06 and 0x07 return the last read value */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700322 cur = i2c_smbus_read_word_data(client, 0);
323 if (i2c_smbus_read_word_data(client, 6) != cur
324 || i2c_smbus_read_word_data(client, 7) != cur)
Jean Delvare747d9be2009-12-09 20:35:52 +0100325 return -ENODEV;
Guenter Roeckefd2d112012-06-02 09:58:09 -0700326 hyst = i2c_smbus_read_word_data(client, 2);
327 if (i2c_smbus_read_word_data(client, 6) != hyst
328 || i2c_smbus_read_word_data(client, 7) != hyst)
Jean Delvare747d9be2009-12-09 20:35:52 +0100329 return -ENODEV;
Guenter Roeckefd2d112012-06-02 09:58:09 -0700330 min = i2c_smbus_read_word_data(client, 4);
331 if (i2c_smbus_read_word_data(client, 6) != min
332 || i2c_smbus_read_word_data(client, 7) != min)
Jean Delvare747d9be2009-12-09 20:35:52 +0100333 return -ENODEV;
334
Jean Delvarea189dd62008-07-16 19:30:13 +0200335 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Jean Delvarea189dd62008-07-16 19:30:13 +0200337 return 0;
338}
339
Guenter Roeckefd2d112012-06-02 09:58:09 -0700340static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id)
Jean Delvarea189dd62008-07-16 19:30:13 +0200341{
Guenter Roeckefd2d112012-06-02 09:58:09 -0700342 struct device *dev = &client->dev;
Jean Delvarea189dd62008-07-16 19:30:13 +0200343 struct lm77_data *data;
344 int err;
345
Guenter Roeck52714c02012-06-16 18:24:02 -0700346 data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
347 if (!data)
348 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
Guenter Roeckefd2d112012-06-02 09:58:09 -0700350 i2c_set_clientdata(client, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 data->valid = 0;
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100352 mutex_init(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 /* Initialize the LM77 chip */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700355 lm77_init_client(client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357 /* Register sysfs hooks */
Guenter Roeckefd2d112012-06-02 09:58:09 -0700358 err = sysfs_create_group(&dev->kobj, &lm77_group);
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800359 if (err)
Guenter Roeck52714c02012-06-16 18:24:02 -0700360 return err;
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200361
Guenter Roeckefd2d112012-06-02 09:58:09 -0700362 data->hwmon_dev = hwmon_device_register(dev);
Tony Jones1beeffe2007-08-20 13:46:20 -0700363 if (IS_ERR(data->hwmon_dev)) {
364 err = PTR_ERR(data->hwmon_dev);
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200365 goto exit_remove;
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400366 }
367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 return 0;
369
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200370exit_remove:
Guenter Roeckefd2d112012-06-02 09:58:09 -0700371 sysfs_remove_group(&dev->kobj, &lm77_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 return err;
373}
374
Jean Delvarea189dd62008-07-16 19:30:13 +0200375static int lm77_remove(struct i2c_client *client)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400377 struct lm77_data *data = i2c_get_clientdata(client);
Tony Jones1beeffe2007-08-20 13:46:20 -0700378 hwmon_device_unregister(data->hwmon_dev);
Mark M. Hoffman0501a3812006-09-24 21:14:35 +0200379 sysfs_remove_group(&client->dev.kobj, &lm77_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 return 0;
381}
382
Guenter Roeck02fe2fd2012-01-14 13:42:20 -0800383/*
384 * All registers are word-sized, except for the configuration register.
385 * The LM77 uses the high-byte first convention.
386 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387static u16 lm77_read_value(struct i2c_client *client, u8 reg)
388{
389 if (reg == LM77_REG_CONF)
390 return i2c_smbus_read_byte_data(client, reg);
391 else
Jean Delvare90f41022011-11-04 12:00:47 +0100392 return i2c_smbus_read_word_swapped(client, reg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393}
394
395static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
396{
397 if (reg == LM77_REG_CONF)
398 return i2c_smbus_write_byte_data(client, reg, value);
399 else
Jean Delvare90f41022011-11-04 12:00:47 +0100400 return i2c_smbus_write_word_swapped(client, reg, value);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401}
402
403static void lm77_init_client(struct i2c_client *client)
404{
405 /* Initialize the LM77 chip - turn off shutdown mode */
406 int conf = lm77_read_value(client, LM77_REG_CONF);
407 if (conf & 1)
408 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
409}
410
411static struct lm77_data *lm77_update_device(struct device *dev)
412{
413 struct i2c_client *client = to_i2c_client(dev);
414 struct lm77_data *data = i2c_get_clientdata(client);
415
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100416 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
419 || !data->valid) {
420 dev_dbg(&client->dev, "Starting lm77 update\n");
421 data->temp_input =
422 LM77_TEMP_FROM_REG(lm77_read_value(client,
423 LM77_REG_TEMP));
424 data->temp_hyst =
425 LM77_TEMP_FROM_REG(lm77_read_value(client,
426 LM77_REG_TEMP_HYST));
427 data->temp_crit =
428 LM77_TEMP_FROM_REG(lm77_read_value(client,
429 LM77_REG_TEMP_CRIT));
430 data->temp_min =
431 LM77_TEMP_FROM_REG(lm77_read_value(client,
432 LM77_REG_TEMP_MIN));
433 data->temp_max =
434 LM77_TEMP_FROM_REG(lm77_read_value(client,
435 LM77_REG_TEMP_MAX));
436 data->alarms =
437 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
438 data->last_updated = jiffies;
439 data->valid = 1;
440 }
441
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100442 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443
444 return data;
445}
446
Axel Linf0967ee2012-01-20 15:38:18 +0800447module_i2c_driver(lm77_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
449MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
450MODULE_DESCRIPTION("LM77 driver");
451MODULE_LICENSE("GPL");