blob: 74ca2c8c61c3ae4996a46bcf523dba87b26f2561 [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>
27#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include "lm75.h"
29
30
31/* Addresses to scan */
32static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
33 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35/* Insmod parameters */
Jean Delvaref4b50262005-07-31 21:49:03 +020036I2C_CLIENT_INSMOD_1(lm75);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38/* Many LM75 constants specified below */
39
40/* The LM75 registers */
41#define LM75_REG_TEMP 0x00
42#define LM75_REG_CONF 0x01
43#define LM75_REG_TEMP_HYST 0x02
44#define LM75_REG_TEMP_OS 0x03
45
46/* Each client has this additional data */
47struct lm75_data {
48 struct i2c_client client;
Mark M. Hoffman943b0832005-07-15 21:39:18 -040049 struct class_device *class_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 struct semaphore update_lock;
51 char valid; /* !=0 if following fields are valid */
52 unsigned long last_updated; /* In jiffies */
53 u16 temp_input; /* Register values */
54 u16 temp_max;
55 u16 temp_hyst;
56};
57
58static int lm75_attach_adapter(struct i2c_adapter *adapter);
59static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
60static void lm75_init_client(struct i2c_client *client);
61static int lm75_detach_client(struct i2c_client *client);
62static int lm75_read_value(struct i2c_client *client, u8 reg);
63static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
64static struct lm75_data *lm75_update_device(struct device *dev);
65
66
67/* This is the driver that will be inserted */
68static struct i2c_driver lm75_driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010069 .driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010070 .name = "lm75",
71 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 .id = I2C_DRIVERID_LM75,
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 .attach_adapter = lm75_attach_adapter,
74 .detach_client = lm75_detach_client,
75};
76
77#define show(value) \
Yani Ioannou30f74292005-05-17 06:41:35 -040078static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{ \
80 struct lm75_data *data = lm75_update_device(dev); \
81 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
82}
83show(temp_max);
84show(temp_hyst);
85show(temp_input);
86
87#define set(value, reg) \
Yani Ioannou30f74292005-05-17 06:41:35 -040088static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{ \
90 struct i2c_client *client = to_i2c_client(dev); \
91 struct lm75_data *data = i2c_get_clientdata(client); \
92 int temp = simple_strtoul(buf, NULL, 10); \
93 \
94 down(&data->update_lock); \
95 data->value = LM75_TEMP_TO_REG(temp); \
96 lm75_write_value(client, reg, data->value); \
97 up(&data->update_lock); \
98 return count; \
99}
100set(temp_max, LM75_REG_TEMP_OS);
101set(temp_hyst, LM75_REG_TEMP_HYST);
102
103static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
104static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst);
105static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);
106
107static int lm75_attach_adapter(struct i2c_adapter *adapter)
108{
109 if (!(adapter->class & I2C_CLASS_HWMON))
110 return 0;
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200111 return i2c_probe(adapter, &addr_data, lm75_detect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112}
113
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200114/* This function is called by i2c_probe */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
116{
117 int i;
118 struct i2c_client *new_client;
119 struct lm75_data *data;
120 int err = 0;
121 const char *name = "";
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
124 I2C_FUNC_SMBUS_WORD_DATA))
125 goto exit;
126
127 /* OK. For now, we presume we have a valid client. We now create the
128 client structure, even though we cannot fill it completely yet.
129 But it allows us to access lm75_{read,write}_value. */
Deepak Saxenaba9c2e82005-10-17 23:08:32 +0200130 if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 err = -ENOMEM;
132 goto exit;
133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135 new_client = &data->client;
136 i2c_set_clientdata(new_client, data);
137 new_client->addr = address;
138 new_client->adapter = adapter;
139 new_client->driver = &lm75_driver;
140 new_client->flags = 0;
141
142 /* Now, we do the remaining detection. There is no identification-
143 dedicated register so we have to rely on several tricks:
144 unused bits, registers cycling over 8-address boundaries,
145 addresses 0x04-0x07 returning the last read value.
146 The cycling+unused addresses combination is not tested,
147 since it would significantly slow the detection down and would
148 hardly add any value. */
149 if (kind < 0) {
150 int cur, conf, hyst, os;
151
152 /* Unused addresses */
153 cur = i2c_smbus_read_word_data(new_client, 0);
154 conf = i2c_smbus_read_byte_data(new_client, 1);
155 hyst = i2c_smbus_read_word_data(new_client, 2);
156 if (i2c_smbus_read_word_data(new_client, 4) != hyst
157 || i2c_smbus_read_word_data(new_client, 5) != hyst
158 || i2c_smbus_read_word_data(new_client, 6) != hyst
159 || i2c_smbus_read_word_data(new_client, 7) != hyst)
160 goto exit_free;
161 os = i2c_smbus_read_word_data(new_client, 3);
162 if (i2c_smbus_read_word_data(new_client, 4) != os
163 || i2c_smbus_read_word_data(new_client, 5) != os
164 || i2c_smbus_read_word_data(new_client, 6) != os
165 || i2c_smbus_read_word_data(new_client, 7) != os)
166 goto exit_free;
167
168 /* Unused bits */
169 if (conf & 0xe0)
170 goto exit_free;
171
172 /* Addresses cycling */
173 for (i = 8; i < 0xff; i += 8)
174 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
175 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
176 || i2c_smbus_read_word_data(new_client, i + 3) != os)
177 goto exit_free;
178 }
179
180 /* Determine the chip type - only one kind supported! */
181 if (kind <= 0)
182 kind = lm75;
183
184 if (kind == lm75) {
185 name = "lm75";
186 }
187
188 /* Fill in the remaining client fields and put it into the global list */
189 strlcpy(new_client->name, name, I2C_NAME_SIZE);
190 data->valid = 0;
191 init_MUTEX(&data->update_lock);
192
193 /* Tell the I2C layer a new client has arrived */
194 if ((err = i2c_attach_client(new_client)))
195 goto exit_free;
196
197 /* Initialize the LM75 chip */
198 lm75_init_client(new_client);
199
200 /* Register sysfs hooks */
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400201 data->class_dev = hwmon_device_register(&new_client->dev);
202 if (IS_ERR(data->class_dev)) {
203 err = PTR_ERR(data->class_dev);
204 goto exit_detach;
205 }
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 device_create_file(&new_client->dev, &dev_attr_temp1_max);
208 device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
209 device_create_file(&new_client->dev, &dev_attr_temp1_input);
210
211 return 0;
212
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400213exit_detach:
214 i2c_detach_client(new_client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215exit_free:
216 kfree(data);
217exit:
218 return err;
219}
220
221static int lm75_detach_client(struct i2c_client *client)
222{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400223 struct lm75_data *data = i2c_get_clientdata(client);
224 hwmon_device_unregister(data->class_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 i2c_detach_client(client);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400226 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 return 0;
228}
229
230/* All registers are word-sized, except for the configuration register.
231 LM75 uses a high-byte first convention, which is exactly opposite to
232 the usual practice. */
233static int lm75_read_value(struct i2c_client *client, u8 reg)
234{
235 if (reg == LM75_REG_CONF)
236 return i2c_smbus_read_byte_data(client, reg);
237 else
238 return swab16(i2c_smbus_read_word_data(client, reg));
239}
240
241/* All registers are word-sized, except for the configuration register.
242 LM75 uses a high-byte first convention, which is exactly opposite to
243 the usual practice. */
244static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
245{
246 if (reg == LM75_REG_CONF)
247 return i2c_smbus_write_byte_data(client, reg, value);
248 else
249 return i2c_smbus_write_word_data(client, reg, swab16(value));
250}
251
252static void lm75_init_client(struct i2c_client *client)
253{
Jean Delvaree647ecf2005-07-27 21:28:28 +0200254 int reg;
255
256 /* Enable if in shutdown mode */
257 reg = lm75_read_value(client, LM75_REG_CONF);
258 if (reg >= 0 && (reg & 0x01))
259 lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260}
261
262static struct lm75_data *lm75_update_device(struct device *dev)
263{
264 struct i2c_client *client = to_i2c_client(dev);
265 struct lm75_data *data = i2c_get_clientdata(client);
266
267 down(&data->update_lock);
268
269 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
270 || !data->valid) {
271 dev_dbg(&client->dev, "Starting lm75 update\n");
272
273 data->temp_input = lm75_read_value(client, LM75_REG_TEMP);
274 data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS);
275 data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST);
276 data->last_updated = jiffies;
277 data->valid = 1;
278 }
279
280 up(&data->update_lock);
281
282 return data;
283}
284
285static int __init sensors_lm75_init(void)
286{
287 return i2c_add_driver(&lm75_driver);
288}
289
290static void __exit sensors_lm75_exit(void)
291{
292 i2c_del_driver(&lm75_driver);
293}
294
295MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
296MODULE_DESCRIPTION("LM75 driver");
297MODULE_LICENSE("GPL");
298
299module_init(sensors_lm75_init);
300module_exit(sensors_lm75_exit);