]>
Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
caaa0f36 S |
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 | */ | |
1da177e4 | 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 | ||
01a52397 DB |
33 | /* |
34 | * This driver handles the LM75 and compatible digital temperature sensors. | |
01a52397 DB |
35 | */ |
36 | ||
9ebd3d82 | 37 | enum lm75_type { /* keep sorted in alphabetical order */ |
e96f9d89 | 38 | adt75, |
1f86df49 | 39 | ds1775, |
9ebd3d82 | 40 | ds75, |
1f86df49 | 41 | lm75, |
9ebd3d82 DB |
42 | lm75a, |
43 | max6625, | |
44 | max6626, | |
45 | mcp980x, | |
46 | stds75, | |
47 | tcn75, | |
48 | tmp100, | |
49 | tmp101, | |
6d034059 | 50 | tmp105, |
9ebd3d82 DB |
51 | tmp175, |
52 | tmp275, | |
53 | tmp75, | |
54 | }; | |
55 | ||
8ff69eeb | 56 | /* Addresses scanned */ |
25e9c86d | 57 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
1da177e4 | 58 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
1da177e4 | 59 | |
1da177e4 LT |
60 | |
61 | /* The LM75 registers */ | |
1da177e4 | 62 | #define LM75_REG_CONF 0x01 |
9ca8e40c JD |
63 | static const u8 LM75_REG_TEMP[3] = { |
64 | 0x00, /* input */ | |
65 | 0x03, /* max */ | |
66 | 0x02, /* hyst */ | |
67 | }; | |
1da177e4 LT |
68 | |
69 | /* Each client has this additional data */ | |
70 | struct lm75_data { | |
01a52397 | 71 | struct device *hwmon_dev; |
9a61bf63 | 72 | struct mutex update_lock; |
9ebd3d82 | 73 | u8 orig_conf; |
01a52397 | 74 | char valid; /* !=0 if registers are valid */ |
1da177e4 | 75 | unsigned long last_updated; /* In jiffies */ |
9ca8e40c JD |
76 | u16 temp[3]; /* Register values, |
77 | 0 = input | |
78 | 1 = max | |
79 | 2 = hyst */ | |
1da177e4 LT |
80 | }; |
81 | ||
1da177e4 LT |
82 | static int lm75_read_value(struct i2c_client *client, u8 reg); |
83 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
84 | static struct lm75_data *lm75_update_device(struct device *dev); | |
85 | ||
86 | ||
01a52397 DB |
87 | /*-----------------------------------------------------------------------*/ |
88 | ||
89 | /* sysfs attributes for hwmon */ | |
1da177e4 | 90 | |
9ca8e40c JD |
91 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, |
92 | char *buf) | |
93 | { | |
94 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
95 | struct lm75_data *data = lm75_update_device(dev); | |
96 | return sprintf(buf, "%d\n", | |
97 | LM75_TEMP_FROM_REG(data->temp[attr->index])); | |
1da177e4 | 98 | } |
9ca8e40c JD |
99 | |
100 | static ssize_t set_temp(struct device *dev, struct device_attribute *da, | |
101 | const char *buf, size_t count) | |
102 | { | |
103 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
104 | struct i2c_client *client = to_i2c_client(dev); | |
105 | struct lm75_data *data = i2c_get_clientdata(client); | |
106 | int nr = attr->index; | |
e3cd9528 S |
107 | long temp; |
108 | int error; | |
109 | ||
110 | error = strict_strtol(buf, 10, &temp); | |
111 | if (error) | |
112 | return error; | |
9ca8e40c JD |
113 | |
114 | mutex_lock(&data->update_lock); | |
115 | data->temp[nr] = LM75_TEMP_TO_REG(temp); | |
116 | lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); | |
117 | mutex_unlock(&data->update_lock); | |
118 | return count; | |
1da177e4 | 119 | } |
1da177e4 | 120 | |
9ca8e40c JD |
121 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
122 | show_temp, set_temp, 1); | |
123 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, | |
124 | show_temp, set_temp, 2); | |
125 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
1da177e4 | 126 | |
c1685f61 | 127 | static struct attribute *lm75_attributes[] = { |
9ca8e40c JD |
128 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
129 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
130 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
c1685f61 MH |
131 | |
132 | NULL | |
133 | }; | |
134 | ||
135 | static const struct attribute_group lm75_group = { | |
136 | .attrs = lm75_attributes, | |
137 | }; | |
138 | ||
01a52397 DB |
139 | /*-----------------------------------------------------------------------*/ |
140 | ||
8ff69eeb | 141 | /* device probe and removal */ |
9ebd3d82 DB |
142 | |
143 | static int | |
144 | lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
145 | { | |
146 | struct lm75_data *data; | |
147 | int status; | |
148 | u8 set_mask, clr_mask; | |
149 | int new; | |
150 | ||
151 | if (!i2c_check_functionality(client->adapter, | |
152 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) | |
153 | return -EIO; | |
154 | ||
155 | data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL); | |
156 | if (!data) | |
157 | return -ENOMEM; | |
158 | ||
159 | i2c_set_clientdata(client, data); | |
9ebd3d82 DB |
160 | mutex_init(&data->update_lock); |
161 | ||
162 | /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. | |
163 | * Then tweak to be more precise when appropriate. | |
164 | */ | |
165 | set_mask = 0; | |
166 | clr_mask = (1 << 0) /* continuous conversions */ | |
167 | | (1 << 6) | (1 << 5); /* 9-bit mode */ | |
168 | ||
169 | /* configure as specified */ | |
170 | status = lm75_read_value(client, LM75_REG_CONF); | |
171 | if (status < 0) { | |
172 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
173 | goto exit_free; | |
174 | } | |
175 | data->orig_conf = status; | |
176 | new = status & ~clr_mask; | |
177 | new |= set_mask; | |
178 | if (status != new) | |
179 | lm75_write_value(client, LM75_REG_CONF, new); | |
180 | dev_dbg(&client->dev, "Config %02x\n", new); | |
181 | ||
182 | /* Register sysfs hooks */ | |
183 | status = sysfs_create_group(&client->dev.kobj, &lm75_group); | |
184 | if (status) | |
185 | goto exit_free; | |
186 | ||
187 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
188 | if (IS_ERR(data->hwmon_dev)) { | |
189 | status = PTR_ERR(data->hwmon_dev); | |
190 | goto exit_remove; | |
191 | } | |
192 | ||
193 | dev_info(&client->dev, "%s: sensor '%s'\n", | |
739cf3a2 | 194 | dev_name(data->hwmon_dev), client->name); |
9ebd3d82 DB |
195 | |
196 | return 0; | |
197 | ||
198 | exit_remove: | |
199 | sysfs_remove_group(&client->dev.kobj, &lm75_group); | |
200 | exit_free: | |
9ebd3d82 DB |
201 | kfree(data); |
202 | return status; | |
203 | } | |
204 | ||
205 | static int lm75_remove(struct i2c_client *client) | |
206 | { | |
207 | struct lm75_data *data = i2c_get_clientdata(client); | |
208 | ||
209 | hwmon_device_unregister(data->hwmon_dev); | |
210 | sysfs_remove_group(&client->dev.kobj, &lm75_group); | |
211 | lm75_write_value(client, LM75_REG_CONF, data->orig_conf); | |
9ebd3d82 DB |
212 | kfree(data); |
213 | return 0; | |
214 | } | |
215 | ||
216 | static const struct i2c_device_id lm75_ids[] = { | |
e96f9d89 | 217 | { "adt75", adt75, }, |
9ebd3d82 DB |
218 | { "ds1775", ds1775, }, |
219 | { "ds75", ds75, }, | |
220 | { "lm75", lm75, }, | |
221 | { "lm75a", lm75a, }, | |
222 | { "max6625", max6625, }, | |
223 | { "max6626", max6626, }, | |
224 | { "mcp980x", mcp980x, }, | |
225 | { "stds75", stds75, }, | |
226 | { "tcn75", tcn75, }, | |
227 | { "tmp100", tmp100, }, | |
228 | { "tmp101", tmp101, }, | |
6d034059 | 229 | { "tmp105", tmp105, }, |
9ebd3d82 DB |
230 | { "tmp175", tmp175, }, |
231 | { "tmp275", tmp275, }, | |
232 | { "tmp75", tmp75, }, | |
233 | { /* LIST END */ } | |
234 | }; | |
235 | MODULE_DEVICE_TABLE(i2c, lm75_ids); | |
236 | ||
05e82fe4 LS |
237 | #define LM75A_ID 0xA1 |
238 | ||
8ff69eeb | 239 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 240 | static int lm75_detect(struct i2c_client *new_client, |
8ff69eeb | 241 | struct i2c_board_info *info) |
1da177e4 | 242 | { |
8ff69eeb | 243 | struct i2c_adapter *adapter = new_client->adapter; |
1da177e4 | 244 | int i; |
e76f67b5 | 245 | int conf, hyst, os; |
05e82fe4 | 246 | bool is_lm75a = 0; |
1da177e4 | 247 | |
1da177e4 LT |
248 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
249 | I2C_FUNC_SMBUS_WORD_DATA)) | |
8ff69eeb | 250 | return -ENODEV; |
1da177e4 | 251 | |
426343ef JD |
252 | /* |
253 | * Now, we do the remaining detection. There is no identification- | |
254 | * dedicated register so we have to rely on several tricks: | |
255 | * unused bits, registers cycling over 8-address boundaries, | |
256 | * addresses 0x04-0x07 returning the last read value. | |
257 | * The cycling+unused addresses combination is not tested, | |
258 | * since it would significantly slow the detection down and would | |
259 | * hardly add any value. | |
260 | * | |
261 | * The National Semiconductor LM75A is different than earlier | |
262 | * LM75s. It has an ID byte of 0xaX (where X is the chip | |
263 | * revision, with 1 being the only revision in existence) in | |
264 | * register 7, and unused registers return 0xff rather than the | |
265 | * last read value. | |
266 | * | |
267 | * Note that this function only detects the original National | |
268 | * Semiconductor LM75 and the LM75A. Clones from other vendors | |
269 | * aren't detected, on purpose, because they are typically never | |
270 | * found on PC hardware. They are found on embedded designs where | |
271 | * they can be instantiated explicitly so detection is not needed. | |
272 | * The absence of identification registers on all these clones | |
273 | * would make their exhaustive detection very difficult and weak, | |
274 | * and odds are that the driver would bind to unsupported devices. | |
275 | */ | |
1da177e4 | 276 | |
e76f67b5 | 277 | /* Unused bits */ |
52df6440 | 278 | conf = i2c_smbus_read_byte_data(new_client, 1); |
e76f67b5 JD |
279 | if (conf & 0xe0) |
280 | return -ENODEV; | |
05e82fe4 LS |
281 | |
282 | /* First check for LM75A */ | |
283 | if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { | |
284 | /* LM75A returns 0xff on unused registers so | |
285 | just to be sure we check for that too. */ | |
286 | if (i2c_smbus_read_byte_data(new_client, 4) != 0xff | |
287 | || i2c_smbus_read_byte_data(new_client, 5) != 0xff | |
288 | || i2c_smbus_read_byte_data(new_client, 6) != 0xff) | |
289 | return -ENODEV; | |
290 | is_lm75a = 1; | |
e76f67b5 JD |
291 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
292 | os = i2c_smbus_read_byte_data(new_client, 3); | |
05e82fe4 LS |
293 | } else { /* Traditional style LM75 detection */ |
294 | /* Unused addresses */ | |
e76f67b5 JD |
295 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
296 | if (i2c_smbus_read_byte_data(new_client, 4) != hyst | |
297 | || i2c_smbus_read_byte_data(new_client, 5) != hyst | |
298 | || i2c_smbus_read_byte_data(new_client, 6) != hyst | |
299 | || i2c_smbus_read_byte_data(new_client, 7) != hyst) | |
05e82fe4 | 300 | return -ENODEV; |
e76f67b5 JD |
301 | os = i2c_smbus_read_byte_data(new_client, 3); |
302 | if (i2c_smbus_read_byte_data(new_client, 4) != os | |
303 | || i2c_smbus_read_byte_data(new_client, 5) != os | |
304 | || i2c_smbus_read_byte_data(new_client, 6) != os | |
305 | || i2c_smbus_read_byte_data(new_client, 7) != os) | |
05e82fe4 LS |
306 | return -ENODEV; |
307 | } | |
1da177e4 | 308 | |
52df6440 | 309 | /* Addresses cycling */ |
e76f67b5 | 310 | for (i = 8; i <= 248; i += 40) { |
52df6440 | 311 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf |
e76f67b5 JD |
312 | || i2c_smbus_read_byte_data(new_client, i + 2) != hyst |
313 | || i2c_smbus_read_byte_data(new_client, i + 3) != os) | |
52df6440 | 314 | return -ENODEV; |
05e82fe4 LS |
315 | if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) |
316 | != LM75A_ID) | |
317 | return -ENODEV; | |
1da177e4 LT |
318 | } |
319 | ||
05e82fe4 | 320 | strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); |
c1685f61 | 321 | |
1da177e4 | 322 | return 0; |
01a52397 DB |
323 | } |
324 | ||
9914518e SD |
325 | #ifdef CONFIG_PM |
326 | static int lm75_suspend(struct device *dev) | |
327 | { | |
328 | int status; | |
329 | struct i2c_client *client = to_i2c_client(dev); | |
330 | status = lm75_read_value(client, LM75_REG_CONF); | |
331 | if (status < 0) { | |
332 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
333 | return status; | |
334 | } | |
335 | status = status | LM75_SHUTDOWN; | |
336 | lm75_write_value(client, LM75_REG_CONF, status); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static int lm75_resume(struct device *dev) | |
341 | { | |
342 | int status; | |
343 | struct i2c_client *client = to_i2c_client(dev); | |
344 | status = lm75_read_value(client, LM75_REG_CONF); | |
345 | if (status < 0) { | |
346 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
347 | return status; | |
348 | } | |
349 | status = status & ~LM75_SHUTDOWN; | |
350 | lm75_write_value(client, LM75_REG_CONF, status); | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static const struct dev_pm_ops lm75_dev_pm_ops = { | |
355 | .suspend = lm75_suspend, | |
356 | .resume = lm75_resume, | |
357 | }; | |
358 | #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops) | |
359 | #else | |
360 | #define LM75_DEV_PM_OPS NULL | |
361 | #endif /* CONFIG_PM */ | |
362 | ||
8ff69eeb JD |
363 | static struct i2c_driver lm75_driver = { |
364 | .class = I2C_CLASS_HWMON, | |
01a52397 | 365 | .driver = { |
8ff69eeb | 366 | .name = "lm75", |
9914518e | 367 | .pm = LM75_DEV_PM_OPS, |
01a52397 | 368 | }, |
8ff69eeb JD |
369 | .probe = lm75_probe, |
370 | .remove = lm75_remove, | |
371 | .id_table = lm75_ids, | |
372 | .detect = lm75_detect, | |
c3813d6a | 373 | .address_list = normal_i2c, |
01a52397 DB |
374 | }; |
375 | ||
376 | /*-----------------------------------------------------------------------*/ | |
377 | ||
378 | /* register access */ | |
379 | ||
caaa0f36 S |
380 | /* |
381 | * All registers are word-sized, except for the configuration register. | |
382 | * LM75 uses a high-byte first convention, which is exactly opposite to | |
383 | * the SMBus standard. | |
384 | */ | |
1da177e4 LT |
385 | static int lm75_read_value(struct i2c_client *client, u8 reg) |
386 | { | |
bcccc3a2 DB |
387 | int value; |
388 | ||
1da177e4 LT |
389 | if (reg == LM75_REG_CONF) |
390 | return i2c_smbus_read_byte_data(client, reg); | |
bcccc3a2 DB |
391 | |
392 | value = i2c_smbus_read_word_data(client, reg); | |
393 | return (value < 0) ? value : swab16(value); | |
1da177e4 LT |
394 | } |
395 | ||
1da177e4 LT |
396 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) |
397 | { | |
398 | if (reg == LM75_REG_CONF) | |
399 | return i2c_smbus_write_byte_data(client, reg, value); | |
400 | else | |
401 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
402 | } | |
403 | ||
1da177e4 LT |
404 | static struct lm75_data *lm75_update_device(struct device *dev) |
405 | { | |
406 | struct i2c_client *client = to_i2c_client(dev); | |
407 | struct lm75_data *data = i2c_get_clientdata(client); | |
408 | ||
9a61bf63 | 409 | mutex_lock(&data->update_lock); |
1da177e4 LT |
410 | |
411 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
412 | || !data->valid) { | |
9ca8e40c | 413 | int i; |
1da177e4 LT |
414 | dev_dbg(&client->dev, "Starting lm75 update\n"); |
415 | ||
bcccc3a2 DB |
416 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) { |
417 | int status; | |
418 | ||
419 | status = lm75_read_value(client, LM75_REG_TEMP[i]); | |
420 | if (status < 0) | |
421 | dev_dbg(&client->dev, "reg %d, err %d\n", | |
422 | LM75_REG_TEMP[i], status); | |
423 | else | |
424 | data->temp[i] = status; | |
425 | } | |
1da177e4 LT |
426 | data->last_updated = jiffies; |
427 | data->valid = 1; | |
428 | } | |
429 | ||
9a61bf63 | 430 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
431 | |
432 | return data; | |
433 | } | |
434 | ||
01a52397 DB |
435 | /*-----------------------------------------------------------------------*/ |
436 | ||
437 | /* module glue */ | |
438 | ||
1da177e4 LT |
439 | static int __init sensors_lm75_init(void) |
440 | { | |
8ff69eeb | 441 | return i2c_add_driver(&lm75_driver); |
1da177e4 LT |
442 | } |
443 | ||
444 | static void __exit sensors_lm75_exit(void) | |
445 | { | |
446 | i2c_del_driver(&lm75_driver); | |
447 | } | |
448 | ||
449 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
450 | MODULE_DESCRIPTION("LM75 driver"); | |
451 | MODULE_LICENSE("GPL"); | |
452 | ||
453 | module_init(sensors_lm75_init); | |
454 | module_exit(sensors_lm75_exit); |