?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
i2c: Drop I2C_CLIENT_INSMOD_1
[wandboard.git] / drivers / hwmon / lm75.c
blob8ae2cfe2d827257a0e1eedbd61d1dc0e9fc8d572
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
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>
26 #include <linux/hwmon.h>
27 #include <linux/hwmon-sysfs.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
30 #include "lm75.h"
31
32
33 /*
34 * This driver handles the LM75 and compatible digital temperature sensors.
35 */
36
37 enum lm75_type { /* keep sorted in alphabetical order */
38 ds1775,
39 ds75,
40 lm75,
41 lm75a,
42 max6625,
43 max6626,
44 mcp980x,
45 stds75,
46 tcn75,
47 tmp100,
48 tmp101,
49 tmp175,
50 tmp275,
51 tmp75,
52 };
53
54 /* Addresses scanned */
55 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
56 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
57
58
59 /* The LM75 registers */
60 #define LM75_REG_CONF 0x01
61 static const u8 LM75_REG_TEMP[3] = {
62 0x00, /* input */
63 0x03, /* max */
64 0x02, /* hyst */
65 };
66
67 /* Each client has this additional data */
68 struct lm75_data {
69 struct device *hwmon_dev;
70 struct mutex update_lock;
71 u8 orig_conf;
72 char valid; /* !=0 if registers are valid */
73 unsigned long last_updated; /* In jiffies */
74 u16 temp[3]; /* Register values,
75 0 = input
76 1 = max
77 2 = hyst */
78 };
79
80 static int lm75_read_value(struct i2c_client *client, u8 reg);
81 static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
82 static struct lm75_data *lm75_update_device(struct device *dev);
83
84
85 /*-----------------------------------------------------------------------*/
86
87 /* sysfs attributes for hwmon */
88
89 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
90 char *buf)
91 {
92 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
93 struct lm75_data *data = lm75_update_device(dev);
94 return sprintf(buf, "%d\n",
95 LM75_TEMP_FROM_REG(data->temp[attr->index]));
96 }
97
98 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
99 const char *buf, size_t count)
100 {
101 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
102 struct i2c_client *client = to_i2c_client(dev);
103 struct lm75_data *data = i2c_get_clientdata(client);
104 int nr = attr->index;
105 long temp = simple_strtol(buf, NULL, 10);
106
107 mutex_lock(&data->update_lock);
108 data->temp[nr] = LM75_TEMP_TO_REG(temp);
109 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
110 mutex_unlock(&data->update_lock);
111 return count;
112 }
113
114 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
115 show_temp, set_temp, 1);
116 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
117 show_temp, set_temp, 2);
118 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
119
120 static struct attribute *lm75_attributes[] = {
121 &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,
124
125 NULL
126 };
127
128 static const struct attribute_group lm75_group = {
129 .attrs = lm75_attributes,
130 };
131
132 /*-----------------------------------------------------------------------*/
133
134 /* device probe and removal */
135
136 static int
137 lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
138 {
139 struct lm75_data *data;
140 int status;
141 u8 set_mask, clr_mask;
142 int new;
143
144 if (!i2c_check_functionality(client->adapter,
145 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
146 return -EIO;
147
148 data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
149 if (!data)
150 return -ENOMEM;
151
152 i2c_set_clientdata(client, data);
153 mutex_init(&data->update_lock);
154
155 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
156 * Then tweak to be more precise when appropriate.
157 */
158 set_mask = 0;
159 clr_mask = (1 << 0) /* continuous conversions */
160 | (1 << 6) | (1 << 5); /* 9-bit mode */
161
162 /* configure as specified */
163 status = lm75_read_value(client, LM75_REG_CONF);
164 if (status < 0) {
165 dev_dbg(&client->dev, "Can't read config? %d\n", status);
166 goto exit_free;
167 }
168 data->orig_conf = status;
169 new = status & ~clr_mask;
170 new |= set_mask;
171 if (status != new)
172 lm75_write_value(client, LM75_REG_CONF, new);
173 dev_dbg(&client->dev, "Config %02x\n", new);
174
175 /* Register sysfs hooks */
176 status = sysfs_create_group(&client->dev.kobj, &lm75_group);
177 if (status)
178 goto exit_free;
179
180 data->hwmon_dev = hwmon_device_register(&client->dev);
181 if (IS_ERR(data->hwmon_dev)) {
182 status = PTR_ERR(data->hwmon_dev);
183 goto exit_remove;
184 }
185
186 dev_info(&client->dev, "%s: sensor '%s'\n",
187 dev_name(data->hwmon_dev), client->name);
188
189 return 0;
190
191 exit_remove:
192 sysfs_remove_group(&client->dev.kobj, &lm75_group);
193 exit_free:
194 i2c_set_clientdata(client, NULL);
195 kfree(data);
196 return status;
197 }
198
199 static 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);
206 i2c_set_clientdata(client, NULL);
207 kfree(data);
208 return 0;
209 }
210
211 static const struct i2c_device_id lm75_ids[] = {
212 { "ds1775", ds1775, },
213 { "ds75", ds75, },
214 { "lm75", lm75, },
215 { "lm75a", lm75a, },
216 { "max6625", max6625, },
217 { "max6626", max6626, },
218 { "mcp980x", mcp980x, },
219 { "stds75", stds75, },
220 { "tcn75", tcn75, },
221 { "tmp100", tmp100, },
222 { "tmp101", tmp101, },
223 { "tmp175", tmp175, },
224 { "tmp275", tmp275, },
225 { "tmp75", tmp75, },
226 { /* LIST END */ }
227 };
228 MODULE_DEVICE_TABLE(i2c, lm75_ids);
229
230 /* Return 0 if detection is successful, -ENODEV otherwise */
231 static int lm75_detect(struct i2c_client *new_client,
232 struct i2c_board_info *info)
233 {
234 struct i2c_adapter *adapter = new_client->adapter;
235 int i;
236 int cur, conf, hyst, os;
237
238 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
239 I2C_FUNC_SMBUS_WORD_DATA))
240 return -ENODEV;
241
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. */
249
250 /* 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;
265
266 /* Unused bits */
267 if (conf & 0xe0)
268 return -ENODEV;
269
270 /* 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;
276 }
277
278 strlcpy(info->type, "lm75", I2C_NAME_SIZE);
279
280 return 0;
281 }
282
283 static struct i2c_driver lm75_driver = {
284 .class = I2C_CLASS_HWMON,
285 .driver = {
286 .name = "lm75",
287 },
288 .probe = lm75_probe,
289 .remove = lm75_remove,
290 .id_table = lm75_ids,
291 .detect = lm75_detect,
292 .address_list = normal_i2c,
293 };
294
295 /*-----------------------------------------------------------------------*/
296
297 /* register access */
298
299 /* All registers are word-sized, except for the configuration register.
300 LM75 uses a high-byte first convention, which is exactly opposite to
301 the SMBus standard. */
302 static int lm75_read_value(struct i2c_client *client, u8 reg)
303 {
304 int value;
305
306 if (reg == LM75_REG_CONF)
307 return i2c_smbus_read_byte_data(client, reg);
308
309 value = i2c_smbus_read_word_data(client, reg);
310 return (value < 0) ? value : swab16(value);
311 }
312
313 static 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
321 static 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
326 mutex_lock(&data->update_lock);
327
328 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
329 || !data->valid) {
330 int i;
331 dev_dbg(&client->dev, "Starting lm75 update\n");
332
333 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 }
343 data->last_updated = jiffies;
344 data->valid = 1;
345 }
346
347 mutex_unlock(&data->update_lock);
348
349 return data;
350 }
351
352 /*-----------------------------------------------------------------------*/
353
354 /* module glue */
355
356 static int __init sensors_lm75_init(void)
357 {
358 return i2c_add_driver(&lm75_driver);
359 }
360
361 static void __exit sensors_lm75_exit(void)
362 {
363 i2c_del_driver(&lm75_driver);
364 }
365
366 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
367 MODULE_DESCRIPTION("LM75 driver");
368 MODULE_LICENSE("GPL");
369
370 module_init(sensors_lm75_init);
371 module_exit(sensors_lm75_exit);
WandBoard kernel