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hwmon: (abituguru3) update driver detection
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1da177e4
LT
1/*
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
1da177e4
LT
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/jiffies.h>
25#include <linux/i2c.h>
943b0830 26#include <linux/hwmon.h>
9ca8e40c 27#include <linux/hwmon-sysfs.h>
943b0830 28#include <linux/err.h>
9a61bf63 29#include <linux/mutex.h>
1da177e4
LT
30#include "lm75.h"
31
32
33/* Addresses to scan */
25e9c86d 34static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
1da177e4 35 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4
LT
36
37/* Insmod parameters */
f4b50261 38I2C_CLIENT_INSMOD_1(lm75);
1da177e4
LT
39
40/* Many LM75 constants specified below */
41
42/* The LM75 registers */
1da177e4 43#define LM75_REG_CONF 0x01
9ca8e40c
JD
44static const u8 LM75_REG_TEMP[3] = {
45 0x00, /* input */
46 0x03, /* max */
47 0x02, /* hyst */
48};
1da177e4
LT
49
50/* Each client has this additional data */
51struct lm75_data {
52 struct i2c_client client;
1beeffe4 53 struct device *hwmon_dev;
9a61bf63 54 struct mutex update_lock;
1da177e4
LT
55 char valid; /* !=0 if following fields are valid */
56 unsigned long last_updated; /* In jiffies */
9ca8e40c
JD
57 u16 temp[3]; /* Register values,
58 0 = input
59 1 = max
60 2 = hyst */
1da177e4
LT
61};
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 = {
cdaf7934 74 .driver = {
cdaf7934
LR
75 .name = "lm75",
76 },
1da177e4
LT
77 .attach_adapter = lm75_attach_adapter,
78 .detach_client = lm75_detach_client,
79};
80
9ca8e40c
JD
81static ssize_t show_temp(struct device *dev, struct device_attribute *da,
82 char *buf)
83{
84 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
85 struct lm75_data *data = lm75_update_device(dev);
86 return sprintf(buf, "%d\n",
87 LM75_TEMP_FROM_REG(data->temp[attr->index]));
1da177e4 88}
9ca8e40c
JD
89
90static ssize_t set_temp(struct device *dev, struct device_attribute *da,
91 const char *buf, size_t count)
92{
93 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
94 struct i2c_client *client = to_i2c_client(dev);
95 struct lm75_data *data = i2c_get_clientdata(client);
96 int nr = attr->index;
5bfedac0 97 long temp = simple_strtol(buf, NULL, 10);
9ca8e40c
JD
98
99 mutex_lock(&data->update_lock);
100 data->temp[nr] = LM75_TEMP_TO_REG(temp);
101 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
102 mutex_unlock(&data->update_lock);
103 return count;
1da177e4 104}
1da177e4 105
9ca8e40c
JD
106static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
107 show_temp, set_temp, 1);
108static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
109 show_temp, set_temp, 2);
110static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
1da177e4
LT
111
112static int lm75_attach_adapter(struct i2c_adapter *adapter)
113{
114 if (!(adapter->class & I2C_CLASS_HWMON))
115 return 0;
2ed2dc3c 116 return i2c_probe(adapter, &addr_data, lm75_detect);
1da177e4
LT
117}
118
c1685f61 119static struct attribute *lm75_attributes[] = {
9ca8e40c
JD
120 &sensor_dev_attr_temp1_input.dev_attr.attr,
121 &sensor_dev_attr_temp1_max.dev_attr.attr,
122 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
c1685f61
MH
123
124 NULL
125};
126
127static const struct attribute_group lm75_group = {
128 .attrs = lm75_attributes,
129};
130
2ed2dc3c 131/* This function is called by i2c_probe */
1da177e4
LT
132static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
133{
134 int i;
135 struct i2c_client *new_client;
136 struct lm75_data *data;
137 int err = 0;
138 const char *name = "";
139
1da177e4
LT
140 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
141 I2C_FUNC_SMBUS_WORD_DATA))
142 goto exit;
143
144 /* OK. For now, we presume we have a valid client. We now create the
145 client structure, even though we cannot fill it completely yet.
146 But it allows us to access lm75_{read,write}_value. */
ba9c2e8d 147 if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
1da177e4
LT
148 err = -ENOMEM;
149 goto exit;
150 }
1da177e4
LT
151
152 new_client = &data->client;
153 i2c_set_clientdata(new_client, data);
154 new_client->addr = address;
155 new_client->adapter = adapter;
156 new_client->driver = &lm75_driver;
157 new_client->flags = 0;
158
159 /* Now, we do the remaining detection. There is no identification-
160 dedicated register so we have to rely on several tricks:
161 unused bits, registers cycling over 8-address boundaries,
162 addresses 0x04-0x07 returning the last read value.
163 The cycling+unused addresses combination is not tested,
164 since it would significantly slow the detection down and would
165 hardly add any value. */
166 if (kind < 0) {
167 int cur, conf, hyst, os;
168
169 /* Unused addresses */
170 cur = i2c_smbus_read_word_data(new_client, 0);
171 conf = i2c_smbus_read_byte_data(new_client, 1);
172 hyst = i2c_smbus_read_word_data(new_client, 2);
173 if (i2c_smbus_read_word_data(new_client, 4) != hyst
174 || i2c_smbus_read_word_data(new_client, 5) != hyst
175 || i2c_smbus_read_word_data(new_client, 6) != hyst
176 || i2c_smbus_read_word_data(new_client, 7) != hyst)
177 goto exit_free;
178 os = i2c_smbus_read_word_data(new_client, 3);
179 if (i2c_smbus_read_word_data(new_client, 4) != os
180 || i2c_smbus_read_word_data(new_client, 5) != os
181 || i2c_smbus_read_word_data(new_client, 6) != os
182 || i2c_smbus_read_word_data(new_client, 7) != os)
183 goto exit_free;
184
185 /* Unused bits */
186 if (conf & 0xe0)
187 goto exit_free;
188
189 /* Addresses cycling */
190 for (i = 8; i < 0xff; i += 8)
191 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
192 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
193 || i2c_smbus_read_word_data(new_client, i + 3) != os)
194 goto exit_free;
195 }
196
197 /* Determine the chip type - only one kind supported! */
198 if (kind <= 0)
199 kind = lm75;
200
201 if (kind == lm75) {
202 name = "lm75";
203 }
204
205 /* Fill in the remaining client fields and put it into the global list */
206 strlcpy(new_client->name, name, I2C_NAME_SIZE);
207 data->valid = 0;
9a61bf63 208 mutex_init(&data->update_lock);
1da177e4
LT
209
210 /* Tell the I2C layer a new client has arrived */
211 if ((err = i2c_attach_client(new_client)))
212 goto exit_free;
213
214 /* Initialize the LM75 chip */
215 lm75_init_client(new_client);
216
217 /* Register sysfs hooks */
c1685f61
MH
218 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm75_group)))
219 goto exit_detach;
220
1beeffe4
TJ
221 data->hwmon_dev = hwmon_device_register(&new_client->dev);
222 if (IS_ERR(data->hwmon_dev)) {
223 err = PTR_ERR(data->hwmon_dev);
c1685f61 224 goto exit_remove;
943b0830
MH
225 }
226
1da177e4
LT
227 return 0;
228
c1685f61
MH
229exit_remove:
230 sysfs_remove_group(&new_client->dev.kobj, &lm75_group);
943b0830
MH
231exit_detach:
232 i2c_detach_client(new_client);
1da177e4
LT
233exit_free:
234 kfree(data);
235exit:
236 return err;
237}
238
239static int lm75_detach_client(struct i2c_client *client)
240{
943b0830 241 struct lm75_data *data = i2c_get_clientdata(client);
1beeffe4 242 hwmon_device_unregister(data->hwmon_dev);
c1685f61 243 sysfs_remove_group(&client->dev.kobj, &lm75_group);
1da177e4 244 i2c_detach_client(client);
943b0830 245 kfree(data);
1da177e4
LT
246 return 0;
247}
248
249/* All registers are word-sized, except for the configuration register.
250 LM75 uses a high-byte first convention, which is exactly opposite to
ccd6befc 251 the SMBus standard. */
1da177e4
LT
252static int lm75_read_value(struct i2c_client *client, u8 reg)
253{
254 if (reg == LM75_REG_CONF)
255 return i2c_smbus_read_byte_data(client, reg);
256 else
257 return swab16(i2c_smbus_read_word_data(client, reg));
258}
259
1da177e4
LT
260static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
261{
262 if (reg == LM75_REG_CONF)
263 return i2c_smbus_write_byte_data(client, reg, value);
264 else
265 return i2c_smbus_write_word_data(client, reg, swab16(value));
266}
267
268static void lm75_init_client(struct i2c_client *client)
269{
e647ecf1
JD
270 int reg;
271
272 /* Enable if in shutdown mode */
273 reg = lm75_read_value(client, LM75_REG_CONF);
274 if (reg >= 0 && (reg & 0x01))
275 lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
1da177e4
LT
276}
277
278static struct lm75_data *lm75_update_device(struct device *dev)
279{
280 struct i2c_client *client = to_i2c_client(dev);
281 struct lm75_data *data = i2c_get_clientdata(client);
282
9a61bf63 283 mutex_lock(&data->update_lock);
1da177e4
LT
284
285 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
286 || !data->valid) {
9ca8e40c 287 int i;
1da177e4
LT
288 dev_dbg(&client->dev, "Starting lm75 update\n");
289
9ca8e40c
JD
290 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
291 data->temp[i] = lm75_read_value(client,
292 LM75_REG_TEMP[i]);
1da177e4
LT
293 data->last_updated = jiffies;
294 data->valid = 1;
295 }
296
9a61bf63 297 mutex_unlock(&data->update_lock);
1da177e4
LT
298
299 return data;
300}
301
302static int __init sensors_lm75_init(void)
303{
304 return i2c_add_driver(&lm75_driver);
305}
306
307static void __exit sensors_lm75_exit(void)
308{
309 i2c_del_driver(&lm75_driver);
310}
311
312MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
313MODULE_DESCRIPTION("LM75 driver");
314MODULE_LICENSE("GPL");
315
316module_init(sensors_lm75_init);
317module_exit(sensors_lm75_exit);