blob: 393f354f92a4c012c46ee96a8062f7b604697cdf [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 lm75.c - Part of lm_sensors, Linux kernel modules for hardware
3 monitoring
4 Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19*/
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/jiffies.h>
25#include <linux/i2c.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040026#include <linux/hwmon.h>
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020027#include <linux/hwmon-sysfs.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040028#include <linux/err.h>
Ingo Molnar9a61bf62006-01-18 23:19:26 +010029#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include "lm75.h"
31
32
David Brownell01a52392008-04-21 12:10:53 -070033/*
34 * This driver handles the LM75 and compatible digital temperature sensors.
David Brownell01a52392008-04-21 12:10:53 -070035 */
36
David Brownell9ebd3d82008-05-03 19:33:15 -070037enum lm75_type { /* keep sorted in alphabetical order */
Jean Delvare1f86df42009-12-14 21:17:26 +010038 ds1775,
David Brownell9ebd3d82008-05-03 19:33:15 -070039 ds75,
Jean Delvare1f86df42009-12-14 21:17:26 +010040 lm75,
David Brownell9ebd3d82008-05-03 19:33:15 -070041 lm75a,
42 max6625,
43 max6626,
44 mcp980x,
45 stds75,
46 tcn75,
47 tmp100,
48 tmp101,
Shubhrajyoti Datta6d034052010-05-27 19:59:03 +020049 tmp105,
David Brownell9ebd3d82008-05-03 19:33:15 -070050 tmp175,
51 tmp275,
52 tmp75,
53};
54
Jean Delvare8ff69ee2008-08-10 22:56:16 +020055/* Addresses scanned */
Mark M. Hoffman25e9c862008-02-17 22:28:03 -050056static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60/* The LM75 registers */
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#define LM75_REG_CONF 0x01
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020062static const u8 LM75_REG_TEMP[3] = {
63 0x00, /* input */
64 0x03, /* max */
65 0x02, /* hyst */
66};
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68/* Each client has this additional data */
69struct lm75_data {
David Brownell01a52392008-04-21 12:10:53 -070070 struct device *hwmon_dev;
Ingo Molnar9a61bf62006-01-18 23:19:26 +010071 struct mutex update_lock;
David Brownell9ebd3d82008-05-03 19:33:15 -070072 u8 orig_conf;
David Brownell01a52392008-04-21 12:10:53 -070073 char valid; /* !=0 if registers are valid */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 unsigned long last_updated; /* In jiffies */
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020075 u16 temp[3]; /* Register values,
76 0 = input
77 1 = max
78 2 = hyst */
Linus Torvalds1da177e2005-04-16 15:20:36 -070079};
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static int lm75_read_value(struct i2c_client *client, u8 reg);
82static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
83static struct lm75_data *lm75_update_device(struct device *dev);
84
85
David Brownell01a52392008-04-21 12:10:53 -070086/*-----------------------------------------------------------------------*/
87
88/* sysfs attributes for hwmon */
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020090static ssize_t show_temp(struct device *dev, struct device_attribute *da,
91 char *buf)
92{
93 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
94 struct lm75_data *data = lm75_update_device(dev);
95 return sprintf(buf, "%d\n",
96 LM75_TEMP_FROM_REG(data->temp[attr->index]));
Linus Torvalds1da177e2005-04-16 15:20:36 -070097}
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020099static ssize_t set_temp(struct device *dev, struct device_attribute *da,
100 const char *buf, size_t count)
101{
102 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
103 struct i2c_client *client = to_i2c_client(dev);
104 struct lm75_data *data = i2c_get_clientdata(client);
105 int nr = attr->index;
Christian Hohnstaedt5bfedac2007-08-16 11:40:10 +0200106 long temp = simple_strtol(buf, NULL, 10);
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200107
108 mutex_lock(&data->update_lock);
109 data->temp[nr] = LM75_TEMP_TO_REG(temp);
110 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
111 mutex_unlock(&data->update_lock);
112 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200115static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
116 show_temp, set_temp, 1);
117static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
118 show_temp, set_temp, 2);
119static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200121static struct attribute *lm75_attributes[] = {
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200122 &sensor_dev_attr_temp1_input.dev_attr.attr,
123 &sensor_dev_attr_temp1_max.dev_attr.attr,
124 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200125
126 NULL
127};
128
129static const struct attribute_group lm75_group = {
130 .attrs = lm75_attributes,
131};
132
David Brownell01a52392008-04-21 12:10:53 -0700133/*-----------------------------------------------------------------------*/
134
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200135/* device probe and removal */
David Brownell9ebd3d82008-05-03 19:33:15 -0700136
137static int
138lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
139{
140 struct lm75_data *data;
141 int status;
142 u8 set_mask, clr_mask;
143 int new;
144
145 if (!i2c_check_functionality(client->adapter,
146 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
147 return -EIO;
148
149 data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
150 if (!data)
151 return -ENOMEM;
152
153 i2c_set_clientdata(client, data);
David Brownell9ebd3d82008-05-03 19:33:15 -0700154 mutex_init(&data->update_lock);
155
156 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
157 * Then tweak to be more precise when appropriate.
158 */
159 set_mask = 0;
160 clr_mask = (1 << 0) /* continuous conversions */
161 | (1 << 6) | (1 << 5); /* 9-bit mode */
162
163 /* configure as specified */
164 status = lm75_read_value(client, LM75_REG_CONF);
165 if (status < 0) {
166 dev_dbg(&client->dev, "Can't read config? %d\n", status);
167 goto exit_free;
168 }
169 data->orig_conf = status;
170 new = status & ~clr_mask;
171 new |= set_mask;
172 if (status != new)
173 lm75_write_value(client, LM75_REG_CONF, new);
174 dev_dbg(&client->dev, "Config %02x\n", new);
175
176 /* Register sysfs hooks */
177 status = sysfs_create_group(&client->dev.kobj, &lm75_group);
178 if (status)
179 goto exit_free;
180
181 data->hwmon_dev = hwmon_device_register(&client->dev);
182 if (IS_ERR(data->hwmon_dev)) {
183 status = PTR_ERR(data->hwmon_dev);
184 goto exit_remove;
185 }
186
187 dev_info(&client->dev, "%s: sensor '%s'\n",
Kay Sievers739cf3a2009-01-06 10:44:41 -0800188 dev_name(data->hwmon_dev), client->name);
David Brownell9ebd3d82008-05-03 19:33:15 -0700189
190 return 0;
191
192exit_remove:
193 sysfs_remove_group(&client->dev.kobj, &lm75_group);
194exit_free:
David Brownell9ebd3d82008-05-03 19:33:15 -0700195 kfree(data);
196 return status;
197}
198
199static int lm75_remove(struct i2c_client *client)
200{
201 struct lm75_data *data = i2c_get_clientdata(client);
202
203 hwmon_device_unregister(data->hwmon_dev);
204 sysfs_remove_group(&client->dev.kobj, &lm75_group);
205 lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
David Brownell9ebd3d82008-05-03 19:33:15 -0700206 kfree(data);
207 return 0;
208}
209
210static const struct i2c_device_id lm75_ids[] = {
211 { "ds1775", ds1775, },
212 { "ds75", ds75, },
213 { "lm75", lm75, },
214 { "lm75a", lm75a, },
215 { "max6625", max6625, },
216 { "max6626", max6626, },
217 { "mcp980x", mcp980x, },
218 { "stds75", stds75, },
219 { "tcn75", tcn75, },
220 { "tmp100", tmp100, },
221 { "tmp101", tmp101, },
Shubhrajyoti Datta6d034052010-05-27 19:59:03 +0200222 { "tmp105", tmp105, },
David Brownell9ebd3d82008-05-03 19:33:15 -0700223 { "tmp175", tmp175, },
224 { "tmp275", tmp275, },
225 { "tmp75", tmp75, },
226 { /* LIST END */ }
227};
228MODULE_DEVICE_TABLE(i2c, lm75_ids);
229
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200230/* Return 0 if detection is successful, -ENODEV otherwise */
Jean Delvare310ec792009-12-14 21:17:23 +0100231static int lm75_detect(struct i2c_client *new_client,
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200232 struct i2c_board_info *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233{
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200234 struct i2c_adapter *adapter = new_client->adapter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 int i;
Jean Delvare52df6442009-12-09 20:35:57 +0100236 int cur, conf, hyst, os;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
239 I2C_FUNC_SMBUS_WORD_DATA))
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200240 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 /* Now, we do the remaining detection. There is no identification-
243 dedicated register so we have to rely on several tricks:
244 unused bits, registers cycling over 8-address boundaries,
245 addresses 0x04-0x07 returning the last read value.
246 The cycling+unused addresses combination is not tested,
247 since it would significantly slow the detection down and would
248 hardly add any value. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Jean Delvare52df6442009-12-09 20:35:57 +0100250 /* Unused addresses */
251 cur = i2c_smbus_read_word_data(new_client, 0);
252 conf = i2c_smbus_read_byte_data(new_client, 1);
253 hyst = i2c_smbus_read_word_data(new_client, 2);
254 if (i2c_smbus_read_word_data(new_client, 4) != hyst
255 || i2c_smbus_read_word_data(new_client, 5) != hyst
256 || i2c_smbus_read_word_data(new_client, 6) != hyst
257 || i2c_smbus_read_word_data(new_client, 7) != hyst)
258 return -ENODEV;
259 os = i2c_smbus_read_word_data(new_client, 3);
260 if (i2c_smbus_read_word_data(new_client, 4) != os
261 || i2c_smbus_read_word_data(new_client, 5) != os
262 || i2c_smbus_read_word_data(new_client, 6) != os
263 || i2c_smbus_read_word_data(new_client, 7) != os)
264 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
Jean Delvare52df6442009-12-09 20:35:57 +0100266 /* Unused bits */
267 if (conf & 0xe0)
268 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Jean Delvare52df6442009-12-09 20:35:57 +0100270 /* Addresses cycling */
271 for (i = 8; i < 0xff; i += 8) {
272 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
273 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
274 || i2c_smbus_read_word_data(new_client, i + 3) != os)
275 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 }
277
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200278 strlcpy(info->type, "lm75", I2C_NAME_SIZE);
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200279
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
282
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200283static struct i2c_driver lm75_driver = {
284 .class = I2C_CLASS_HWMON,
David Brownell01a52392008-04-21 12:10:53 -0700285 .driver = {
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200286 .name = "lm75",
David Brownell01a52392008-04-21 12:10:53 -0700287 },
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200288 .probe = lm75_probe,
289 .remove = lm75_remove,
290 .id_table = lm75_ids,
291 .detect = lm75_detect,
Jean Delvarec3813d62009-12-14 21:17:25 +0100292 .address_list = normal_i2c,
David Brownell01a52392008-04-21 12:10:53 -0700293};
294
295/*-----------------------------------------------------------------------*/
296
297/* register access */
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299/* All registers are word-sized, except for the configuration register.
300 LM75 uses a high-byte first convention, which is exactly opposite to
Jean Delvareccd6bef2008-02-19 12:42:58 +0100301 the SMBus standard. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302static int lm75_read_value(struct i2c_client *client, u8 reg)
303{
David Brownellbcccc3a2008-05-03 19:19:16 -0700304 int value;
305
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 if (reg == LM75_REG_CONF)
307 return i2c_smbus_read_byte_data(client, reg);
David Brownellbcccc3a2008-05-03 19:19:16 -0700308
309 value = i2c_smbus_read_word_data(client, reg);
310 return (value < 0) ? value : swab16(value);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311}
312
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
314{
315 if (reg == LM75_REG_CONF)
316 return i2c_smbus_write_byte_data(client, reg, value);
317 else
318 return i2c_smbus_write_word_data(client, reg, swab16(value));
319}
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321static struct lm75_data *lm75_update_device(struct device *dev)
322{
323 struct i2c_client *client = to_i2c_client(dev);
324 struct lm75_data *data = i2c_get_clientdata(client);
325
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100326 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
329 || !data->valid) {
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200330 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 dev_dbg(&client->dev, "Starting lm75 update\n");
332
David Brownellbcccc3a2008-05-03 19:19:16 -0700333 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
334 int status;
335
336 status = lm75_read_value(client, LM75_REG_TEMP[i]);
337 if (status < 0)
338 dev_dbg(&client->dev, "reg %d, err %d\n",
339 LM75_REG_TEMP[i], status);
340 else
341 data->temp[i] = status;
342 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 data->last_updated = jiffies;
344 data->valid = 1;
345 }
346
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100347 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
349 return data;
350}
351
David Brownell01a52392008-04-21 12:10:53 -0700352/*-----------------------------------------------------------------------*/
353
354/* module glue */
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356static int __init sensors_lm75_init(void)
357{
Jean Delvare8ff69ee2008-08-10 22:56:16 +0200358 return i2c_add_driver(&lm75_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359}
360
361static void __exit sensors_lm75_exit(void)
362{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 i2c_del_driver(&lm75_driver);
364}
365
366MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
367MODULE_DESCRIPTION("LM75 driver");
368MODULE_LICENSE("GPL");
369
370module_init(sensors_lm75_init);
371module_exit(sensors_lm75_exit);