blob: 37a8cc032ffa9a0b535ac26b9d07d37edb78bd3e [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
33/* Addresses to scan */
34static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
35 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37/* Insmod parameters */
Jean Delvaref4b50262005-07-31 21:49:03 +020038I2C_CLIENT_INSMOD_1(lm75);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40/* Many LM75 constants specified below */
41
42/* The LM75 registers */
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define LM75_REG_CONF 0x01
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020044static const u8 LM75_REG_TEMP[3] = {
45 0x00, /* input */
46 0x03, /* max */
47 0x02, /* hyst */
48};
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50/* Each client has this additional data */
51struct lm75_data {
52 struct i2c_client client;
Tony Jones1beeffe2007-08-20 13:46:20 -070053 struct device *hwmon_dev;
Ingo Molnar9a61bf62006-01-18 23:19:26 +010054 struct mutex update_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 char valid; /* !=0 if following fields are valid */
56 unsigned long last_updated; /* In jiffies */
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020057 u16 temp[3]; /* Register values,
58 0 = input
59 1 = max
60 2 = hyst */
Linus Torvalds1da177e2005-04-16 15:20:36 -070061};
62
63static int lm75_attach_adapter(struct i2c_adapter *adapter);
64static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
65static void lm75_init_client(struct i2c_client *client);
66static int lm75_detach_client(struct i2c_client *client);
67static int lm75_read_value(struct i2c_client *client, u8 reg);
68static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
69static struct lm75_data *lm75_update_device(struct device *dev);
70
71
72/* This is the driver that will be inserted */
73static struct i2c_driver lm75_driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010074 .driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010075 .name = "lm75",
76 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 .id = I2C_DRIVERID_LM75,
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 .attach_adapter = lm75_attach_adapter,
79 .detach_client = lm75_detach_client,
80};
81
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020082static ssize_t show_temp(struct device *dev, struct device_attribute *da,
83 char *buf)
84{
85 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
86 struct lm75_data *data = lm75_update_device(dev);
87 return sprintf(buf, "%d\n",
88 LM75_TEMP_FROM_REG(data->temp[attr->index]));
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020091static ssize_t set_temp(struct device *dev, struct device_attribute *da,
92 const char *buf, size_t count)
93{
94 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
95 struct i2c_client *client = to_i2c_client(dev);
96 struct lm75_data *data = i2c_get_clientdata(client);
97 int nr = attr->index;
Christian Hohnstaedt5bfedac2007-08-16 11:40:10 +020098 long temp = simple_strtol(buf, NULL, 10);
Jean Delvare9ca8e40c82007-05-08 17:22:01 +020099
100 mutex_lock(&data->update_lock);
101 data->temp[nr] = LM75_TEMP_TO_REG(temp);
102 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
103 mutex_unlock(&data->update_lock);
104 return count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200107static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
108 show_temp, set_temp, 1);
109static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
110 show_temp, set_temp, 2);
111static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113static int lm75_attach_adapter(struct i2c_adapter *adapter)
114{
115 if (!(adapter->class & I2C_CLASS_HWMON))
116 return 0;
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200117 return i2c_probe(adapter, &addr_data, lm75_detect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118}
119
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200120static struct attribute *lm75_attributes[] = {
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200121 &sensor_dev_attr_temp1_input.dev_attr.attr,
122 &sensor_dev_attr_temp1_max.dev_attr.attr,
123 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200124
125 NULL
126};
127
128static const struct attribute_group lm75_group = {
129 .attrs = lm75_attributes,
130};
131
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200132/* This function is called by i2c_probe */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
134{
135 int i;
136 struct i2c_client *new_client;
137 struct lm75_data *data;
138 int err = 0;
139 const char *name = "";
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
142 I2C_FUNC_SMBUS_WORD_DATA))
143 goto exit;
144
145 /* OK. For now, we presume we have a valid client. We now create the
146 client structure, even though we cannot fill it completely yet.
147 But it allows us to access lm75_{read,write}_value. */
Deepak Saxenaba9c2e82005-10-17 23:08:32 +0200148 if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 err = -ENOMEM;
150 goto exit;
151 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 new_client = &data->client;
154 i2c_set_clientdata(new_client, data);
155 new_client->addr = address;
156 new_client->adapter = adapter;
157 new_client->driver = &lm75_driver;
158 new_client->flags = 0;
159
160 /* Now, we do the remaining detection. There is no identification-
161 dedicated register so we have to rely on several tricks:
162 unused bits, registers cycling over 8-address boundaries,
163 addresses 0x04-0x07 returning the last read value.
164 The cycling+unused addresses combination is not tested,
165 since it would significantly slow the detection down and would
166 hardly add any value. */
167 if (kind < 0) {
168 int cur, conf, hyst, os;
169
170 /* Unused addresses */
171 cur = i2c_smbus_read_word_data(new_client, 0);
172 conf = i2c_smbus_read_byte_data(new_client, 1);
173 hyst = i2c_smbus_read_word_data(new_client, 2);
174 if (i2c_smbus_read_word_data(new_client, 4) != hyst
175 || i2c_smbus_read_word_data(new_client, 5) != hyst
176 || i2c_smbus_read_word_data(new_client, 6) != hyst
177 || i2c_smbus_read_word_data(new_client, 7) != hyst)
178 goto exit_free;
179 os = i2c_smbus_read_word_data(new_client, 3);
180 if (i2c_smbus_read_word_data(new_client, 4) != os
181 || i2c_smbus_read_word_data(new_client, 5) != os
182 || i2c_smbus_read_word_data(new_client, 6) != os
183 || i2c_smbus_read_word_data(new_client, 7) != os)
184 goto exit_free;
185
186 /* Unused bits */
187 if (conf & 0xe0)
188 goto exit_free;
189
190 /* Addresses cycling */
191 for (i = 8; i < 0xff; i += 8)
192 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
193 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
194 || i2c_smbus_read_word_data(new_client, i + 3) != os)
195 goto exit_free;
196 }
197
198 /* Determine the chip type - only one kind supported! */
199 if (kind <= 0)
200 kind = lm75;
201
202 if (kind == lm75) {
203 name = "lm75";
204 }
205
206 /* Fill in the remaining client fields and put it into the global list */
207 strlcpy(new_client->name, name, I2C_NAME_SIZE);
208 data->valid = 0;
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100209 mutex_init(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 /* Tell the I2C layer a new client has arrived */
212 if ((err = i2c_attach_client(new_client)))
213 goto exit_free;
214
215 /* Initialize the LM75 chip */
216 lm75_init_client(new_client);
217
218 /* Register sysfs hooks */
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200219 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm75_group)))
220 goto exit_detach;
221
Tony Jones1beeffe2007-08-20 13:46:20 -0700222 data->hwmon_dev = hwmon_device_register(&new_client->dev);
223 if (IS_ERR(data->hwmon_dev)) {
224 err = PTR_ERR(data->hwmon_dev);
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200225 goto exit_remove;
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400226 }
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 return 0;
229
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200230exit_remove:
231 sysfs_remove_group(&new_client->dev.kobj, &lm75_group);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400232exit_detach:
233 i2c_detach_client(new_client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234exit_free:
235 kfree(data);
236exit:
237 return err;
238}
239
240static int lm75_detach_client(struct i2c_client *client)
241{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400242 struct lm75_data *data = i2c_get_clientdata(client);
Tony Jones1beeffe2007-08-20 13:46:20 -0700243 hwmon_device_unregister(data->hwmon_dev);
Mark M. Hoffmanc1685f62006-09-24 20:59:49 +0200244 sysfs_remove_group(&client->dev.kobj, &lm75_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 i2c_detach_client(client);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400246 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 return 0;
248}
249
250/* All registers are word-sized, except for the configuration register.
251 LM75 uses a high-byte first convention, which is exactly opposite to
252 the usual practice. */
253static int lm75_read_value(struct i2c_client *client, u8 reg)
254{
255 if (reg == LM75_REG_CONF)
256 return i2c_smbus_read_byte_data(client, reg);
257 else
258 return swab16(i2c_smbus_read_word_data(client, reg));
259}
260
261/* All registers are word-sized, except for the configuration register.
262 LM75 uses a high-byte first convention, which is exactly opposite to
263 the usual practice. */
264static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
265{
266 if (reg == LM75_REG_CONF)
267 return i2c_smbus_write_byte_data(client, reg, value);
268 else
269 return i2c_smbus_write_word_data(client, reg, swab16(value));
270}
271
272static void lm75_init_client(struct i2c_client *client)
273{
Jean Delvaree647ecf2005-07-27 21:28:28 +0200274 int reg;
275
276 /* Enable if in shutdown mode */
277 reg = lm75_read_value(client, LM75_REG_CONF);
278 if (reg >= 0 && (reg & 0x01))
279 lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280}
281
282static struct lm75_data *lm75_update_device(struct device *dev)
283{
284 struct i2c_client *client = to_i2c_client(dev);
285 struct lm75_data *data = i2c_get_clientdata(client);
286
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100287 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
289 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
290 || !data->valid) {
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200291 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 dev_dbg(&client->dev, "Starting lm75 update\n");
293
Jean Delvare9ca8e40c82007-05-08 17:22:01 +0200294 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
295 data->temp[i] = lm75_read_value(client,
296 LM75_REG_TEMP[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 data->last_updated = jiffies;
298 data->valid = 1;
299 }
300
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100301 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
303 return data;
304}
305
306static int __init sensors_lm75_init(void)
307{
308 return i2c_add_driver(&lm75_driver);
309}
310
311static void __exit sensors_lm75_exit(void)
312{
313 i2c_del_driver(&lm75_driver);
314}
315
316MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
317MODULE_DESCRIPTION("LM75 driver");
318MODULE_LICENSE("GPL");
319
320module_init(sensors_lm75_init);
321module_exit(sensors_lm75_exit);