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> |
22e73183 EV |
30 | #include <linux/of.h> |
31 | #include <linux/thermal.h> | |
1da177e4 LT |
32 | #include "lm75.h" |
33 | ||
34 | ||
01a52397 DB |
35 | /* |
36 | * This driver handles the LM75 and compatible digital temperature sensors. | |
01a52397 DB |
37 | */ |
38 | ||
9ebd3d82 | 39 | enum lm75_type { /* keep sorted in alphabetical order */ |
e96f9d89 | 40 | adt75, |
1f86df49 | 41 | ds1775, |
9ebd3d82 | 42 | ds75, |
3fbc81e3 | 43 | ds7505, |
c98d6c65 | 44 | g751, |
1f86df49 | 45 | lm75, |
9ebd3d82 DB |
46 | lm75a, |
47 | max6625, | |
48 | max6626, | |
49 | mcp980x, | |
50 | stds75, | |
51 | tcn75, | |
52 | tmp100, | |
53 | tmp101, | |
6d034059 | 54 | tmp105, |
9ebd3d82 DB |
55 | tmp175, |
56 | tmp275, | |
57 | tmp75, | |
58 | }; | |
59 | ||
8ff69eeb | 60 | /* Addresses scanned */ |
25e9c86d | 61 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
1da177e4 | 62 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
1da177e4 | 63 | |
1da177e4 LT |
64 | |
65 | /* The LM75 registers */ | |
1da177e4 | 66 | #define LM75_REG_CONF 0x01 |
9ca8e40c JD |
67 | static const u8 LM75_REG_TEMP[3] = { |
68 | 0x00, /* input */ | |
69 | 0x03, /* max */ | |
70 | 0x02, /* hyst */ | |
71 | }; | |
1da177e4 LT |
72 | |
73 | /* Each client has this additional data */ | |
74 | struct lm75_data { | |
d663ec49 | 75 | struct i2c_client *client; |
01a52397 | 76 | struct device *hwmon_dev; |
22e73183 | 77 | struct thermal_zone_device *tz; |
9a61bf63 | 78 | struct mutex update_lock; |
9ebd3d82 | 79 | u8 orig_conf; |
87d0621a JD |
80 | u8 resolution; /* In bits, between 9 and 12 */ |
81 | u8 resolution_limits; | |
01a52397 | 82 | char valid; /* !=0 if registers are valid */ |
1da177e4 | 83 | unsigned long last_updated; /* In jiffies */ |
87d0621a JD |
84 | unsigned long sample_time; /* In jiffies */ |
85 | s16 temp[3]; /* Register values, | |
9ca8e40c JD |
86 | 0 = input |
87 | 1 = max | |
88 | 2 = hyst */ | |
1da177e4 LT |
89 | }; |
90 | ||
1da177e4 LT |
91 | static int lm75_read_value(struct i2c_client *client, u8 reg); |
92 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
93 | static struct lm75_data *lm75_update_device(struct device *dev); | |
94 | ||
95 | ||
01a52397 DB |
96 | /*-----------------------------------------------------------------------*/ |
97 | ||
22e73183 EV |
98 | static inline long lm75_reg_to_mc(s16 temp, u8 resolution) |
99 | { | |
100 | return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8); | |
101 | } | |
102 | ||
01a52397 | 103 | /* sysfs attributes for hwmon */ |
1da177e4 | 104 | |
22e73183 EV |
105 | static int lm75_read_temp(void *dev, long *temp) |
106 | { | |
107 | struct lm75_data *data = lm75_update_device(dev); | |
108 | ||
109 | if (IS_ERR(data)) | |
110 | return PTR_ERR(data); | |
111 | ||
112 | *temp = lm75_reg_to_mc(data->temp[0], data->resolution); | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
9ca8e40c JD |
117 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, |
118 | char *buf) | |
119 | { | |
120 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
121 | struct lm75_data *data = lm75_update_device(dev); | |
1f962f36 FM |
122 | |
123 | if (IS_ERR(data)) | |
124 | return PTR_ERR(data); | |
125 | ||
22e73183 EV |
126 | return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index], |
127 | data->resolution)); | |
1da177e4 | 128 | } |
9ca8e40c JD |
129 | |
130 | static ssize_t set_temp(struct device *dev, struct device_attribute *da, | |
131 | const char *buf, size_t count) | |
132 | { | |
133 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
d663ec49 GR |
134 | struct lm75_data *data = dev_get_drvdata(dev); |
135 | struct i2c_client *client = data->client; | |
9ca8e40c | 136 | int nr = attr->index; |
e3cd9528 S |
137 | long temp; |
138 | int error; | |
87d0621a | 139 | u8 resolution; |
e3cd9528 | 140 | |
24edc0a7 | 141 | error = kstrtol(buf, 10, &temp); |
e3cd9528 S |
142 | if (error) |
143 | return error; | |
9ca8e40c | 144 | |
87d0621a JD |
145 | /* |
146 | * Resolution of limit registers is assumed to be the same as the | |
147 | * temperature input register resolution unless given explicitly. | |
148 | */ | |
149 | if (attr->index && data->resolution_limits) | |
150 | resolution = data->resolution_limits; | |
151 | else | |
152 | resolution = data->resolution; | |
153 | ||
9ca8e40c | 154 | mutex_lock(&data->update_lock); |
87d0621a JD |
155 | temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); |
156 | data->temp[nr] = DIV_ROUND_CLOSEST(temp << (resolution - 8), | |
157 | 1000) << (16 - resolution); | |
9ca8e40c JD |
158 | lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); |
159 | mutex_unlock(&data->update_lock); | |
160 | return count; | |
1da177e4 | 161 | } |
1da177e4 | 162 | |
9ca8e40c JD |
163 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
164 | show_temp, set_temp, 1); | |
165 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, | |
166 | show_temp, set_temp, 2); | |
167 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
1da177e4 | 168 | |
d663ec49 | 169 | static struct attribute *lm75_attrs[] = { |
9ca8e40c JD |
170 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
171 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
172 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
c1685f61 MH |
173 | |
174 | NULL | |
175 | }; | |
d663ec49 | 176 | ATTRIBUTE_GROUPS(lm75); |
c1685f61 | 177 | |
01a52397 DB |
178 | /*-----------------------------------------------------------------------*/ |
179 | ||
8ff69eeb | 180 | /* device probe and removal */ |
9ebd3d82 DB |
181 | |
182 | static int | |
183 | lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
184 | { | |
d663ec49 | 185 | struct device *dev = &client->dev; |
9ebd3d82 DB |
186 | struct lm75_data *data; |
187 | int status; | |
188 | u8 set_mask, clr_mask; | |
189 | int new; | |
0cd2c72d | 190 | enum lm75_type kind = id->driver_data; |
9ebd3d82 DB |
191 | |
192 | if (!i2c_check_functionality(client->adapter, | |
193 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) | |
194 | return -EIO; | |
195 | ||
d663ec49 | 196 | data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL); |
9ebd3d82 DB |
197 | if (!data) |
198 | return -ENOMEM; | |
199 | ||
d663ec49 | 200 | data->client = client; |
9ebd3d82 | 201 | i2c_set_clientdata(client, data); |
9ebd3d82 DB |
202 | mutex_init(&data->update_lock); |
203 | ||
204 | /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. | |
205 | * Then tweak to be more precise when appropriate. | |
206 | */ | |
207 | set_mask = 0; | |
8a5c5cc6 JD |
208 | clr_mask = LM75_SHUTDOWN; /* continuous conversions */ |
209 | ||
0cd2c72d | 210 | switch (kind) { |
8a5c5cc6 JD |
211 | case adt75: |
212 | clr_mask |= 1 << 5; /* not one-shot mode */ | |
0cd2c72d JD |
213 | data->resolution = 12; |
214 | data->sample_time = HZ / 8; | |
8a5c5cc6 JD |
215 | break; |
216 | case ds1775: | |
217 | case ds75: | |
218 | case stds75: | |
0cd2c72d JD |
219 | clr_mask |= 3 << 5; |
220 | set_mask |= 2 << 5; /* 11-bit mode */ | |
221 | data->resolution = 11; | |
222 | data->sample_time = HZ; | |
223 | break; | |
3fbc81e3 JD |
224 | case ds7505: |
225 | set_mask |= 3 << 5; /* 12-bit mode */ | |
226 | data->resolution = 12; | |
227 | data->sample_time = HZ / 4; | |
228 | break; | |
c98d6c65 | 229 | case g751: |
0cd2c72d JD |
230 | case lm75: |
231 | case lm75a: | |
232 | data->resolution = 9; | |
233 | data->sample_time = HZ / 2; | |
234 | break; | |
235 | case max6625: | |
236 | data->resolution = 9; | |
237 | data->sample_time = HZ / 4; | |
238 | break; | |
239 | case max6626: | |
240 | data->resolution = 12; | |
241 | data->resolution_limits = 9; | |
242 | data->sample_time = HZ / 4; | |
243 | break; | |
244 | case tcn75: | |
245 | data->resolution = 9; | |
246 | data->sample_time = HZ / 8; | |
8a5c5cc6 JD |
247 | break; |
248 | case mcp980x: | |
0cd2c72d JD |
249 | data->resolution_limits = 9; |
250 | /* fall through */ | |
8a5c5cc6 JD |
251 | case tmp100: |
252 | case tmp101: | |
0cd2c72d JD |
253 | set_mask |= 3 << 5; /* 12-bit mode */ |
254 | data->resolution = 12; | |
255 | data->sample_time = HZ; | |
256 | clr_mask |= 1 << 7; /* not one-shot mode */ | |
257 | break; | |
8a5c5cc6 JD |
258 | case tmp105: |
259 | case tmp175: | |
260 | case tmp275: | |
261 | case tmp75: | |
0cd2c72d | 262 | set_mask |= 3 << 5; /* 12-bit mode */ |
8a5c5cc6 | 263 | clr_mask |= 1 << 7; /* not one-shot mode */ |
0cd2c72d JD |
264 | data->resolution = 12; |
265 | data->sample_time = HZ / 2; | |
8a5c5cc6 JD |
266 | break; |
267 | } | |
9ebd3d82 DB |
268 | |
269 | /* configure as specified */ | |
270 | status = lm75_read_value(client, LM75_REG_CONF); | |
271 | if (status < 0) { | |
d663ec49 | 272 | dev_dbg(dev, "Can't read config? %d\n", status); |
13ac7a01 | 273 | return status; |
9ebd3d82 DB |
274 | } |
275 | data->orig_conf = status; | |
276 | new = status & ~clr_mask; | |
277 | new |= set_mask; | |
278 | if (status != new) | |
279 | lm75_write_value(client, LM75_REG_CONF, new); | |
d663ec49 | 280 | dev_dbg(dev, "Config %02x\n", new); |
9ebd3d82 | 281 | |
d663ec49 GR |
282 | data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name, |
283 | data, lm75_groups); | |
284 | if (IS_ERR(data->hwmon_dev)) | |
285 | return PTR_ERR(data->hwmon_dev); | |
9ebd3d82 | 286 | |
d663ec49 | 287 | data->tz = thermal_zone_of_sensor_register(data->hwmon_dev, |
22e73183 | 288 | 0, |
d663ec49 | 289 | data->hwmon_dev, |
22e73183 EV |
290 | lm75_read_temp, NULL); |
291 | if (IS_ERR(data->tz)) | |
292 | data->tz = NULL; | |
293 | ||
d663ec49 | 294 | dev_info(dev, "%s: sensor '%s'\n", |
739cf3a2 | 295 | dev_name(data->hwmon_dev), client->name); |
9ebd3d82 DB |
296 | |
297 | return 0; | |
9ebd3d82 DB |
298 | } |
299 | ||
300 | static int lm75_remove(struct i2c_client *client) | |
301 | { | |
302 | struct lm75_data *data = i2c_get_clientdata(client); | |
303 | ||
d663ec49 | 304 | thermal_zone_of_sensor_unregister(data->hwmon_dev, data->tz); |
9ebd3d82 | 305 | hwmon_device_unregister(data->hwmon_dev); |
9ebd3d82 | 306 | lm75_write_value(client, LM75_REG_CONF, data->orig_conf); |
9ebd3d82 DB |
307 | return 0; |
308 | } | |
309 | ||
310 | static const struct i2c_device_id lm75_ids[] = { | |
e96f9d89 | 311 | { "adt75", adt75, }, |
9ebd3d82 DB |
312 | { "ds1775", ds1775, }, |
313 | { "ds75", ds75, }, | |
3fbc81e3 | 314 | { "ds7505", ds7505, }, |
c98d6c65 | 315 | { "g751", g751, }, |
9ebd3d82 DB |
316 | { "lm75", lm75, }, |
317 | { "lm75a", lm75a, }, | |
318 | { "max6625", max6625, }, | |
319 | { "max6626", max6626, }, | |
320 | { "mcp980x", mcp980x, }, | |
321 | { "stds75", stds75, }, | |
322 | { "tcn75", tcn75, }, | |
323 | { "tmp100", tmp100, }, | |
324 | { "tmp101", tmp101, }, | |
6d034059 | 325 | { "tmp105", tmp105, }, |
9ebd3d82 DB |
326 | { "tmp175", tmp175, }, |
327 | { "tmp275", tmp275, }, | |
328 | { "tmp75", tmp75, }, | |
329 | { /* LIST END */ } | |
330 | }; | |
331 | MODULE_DEVICE_TABLE(i2c, lm75_ids); | |
332 | ||
05e82fe4 LS |
333 | #define LM75A_ID 0xA1 |
334 | ||
8ff69eeb | 335 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 336 | static int lm75_detect(struct i2c_client *new_client, |
8ff69eeb | 337 | struct i2c_board_info *info) |
1da177e4 | 338 | { |
8ff69eeb | 339 | struct i2c_adapter *adapter = new_client->adapter; |
1da177e4 | 340 | int i; |
e76f67b5 | 341 | int conf, hyst, os; |
05e82fe4 | 342 | bool is_lm75a = 0; |
1da177e4 | 343 | |
1da177e4 LT |
344 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
345 | I2C_FUNC_SMBUS_WORD_DATA)) | |
8ff69eeb | 346 | return -ENODEV; |
1da177e4 | 347 | |
426343ef JD |
348 | /* |
349 | * Now, we do the remaining detection. There is no identification- | |
350 | * dedicated register so we have to rely on several tricks: | |
351 | * unused bits, registers cycling over 8-address boundaries, | |
352 | * addresses 0x04-0x07 returning the last read value. | |
353 | * The cycling+unused addresses combination is not tested, | |
354 | * since it would significantly slow the detection down and would | |
355 | * hardly add any value. | |
356 | * | |
357 | * The National Semiconductor LM75A is different than earlier | |
358 | * LM75s. It has an ID byte of 0xaX (where X is the chip | |
359 | * revision, with 1 being the only revision in existence) in | |
360 | * register 7, and unused registers return 0xff rather than the | |
361 | * last read value. | |
362 | * | |
363 | * Note that this function only detects the original National | |
364 | * Semiconductor LM75 and the LM75A. Clones from other vendors | |
365 | * aren't detected, on purpose, because they are typically never | |
366 | * found on PC hardware. They are found on embedded designs where | |
367 | * they can be instantiated explicitly so detection is not needed. | |
368 | * The absence of identification registers on all these clones | |
369 | * would make their exhaustive detection very difficult and weak, | |
370 | * and odds are that the driver would bind to unsupported devices. | |
371 | */ | |
1da177e4 | 372 | |
e76f67b5 | 373 | /* Unused bits */ |
52df6440 | 374 | conf = i2c_smbus_read_byte_data(new_client, 1); |
e76f67b5 JD |
375 | if (conf & 0xe0) |
376 | return -ENODEV; | |
05e82fe4 LS |
377 | |
378 | /* First check for LM75A */ | |
379 | if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { | |
380 | /* LM75A returns 0xff on unused registers so | |
381 | just to be sure we check for that too. */ | |
382 | if (i2c_smbus_read_byte_data(new_client, 4) != 0xff | |
383 | || i2c_smbus_read_byte_data(new_client, 5) != 0xff | |
384 | || i2c_smbus_read_byte_data(new_client, 6) != 0xff) | |
385 | return -ENODEV; | |
386 | is_lm75a = 1; | |
e76f67b5 JD |
387 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
388 | os = i2c_smbus_read_byte_data(new_client, 3); | |
05e82fe4 LS |
389 | } else { /* Traditional style LM75 detection */ |
390 | /* Unused addresses */ | |
e76f67b5 JD |
391 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
392 | if (i2c_smbus_read_byte_data(new_client, 4) != hyst | |
393 | || i2c_smbus_read_byte_data(new_client, 5) != hyst | |
394 | || i2c_smbus_read_byte_data(new_client, 6) != hyst | |
395 | || i2c_smbus_read_byte_data(new_client, 7) != hyst) | |
05e82fe4 | 396 | return -ENODEV; |
e76f67b5 JD |
397 | os = i2c_smbus_read_byte_data(new_client, 3); |
398 | if (i2c_smbus_read_byte_data(new_client, 4) != os | |
399 | || i2c_smbus_read_byte_data(new_client, 5) != os | |
400 | || i2c_smbus_read_byte_data(new_client, 6) != os | |
401 | || i2c_smbus_read_byte_data(new_client, 7) != os) | |
05e82fe4 LS |
402 | return -ENODEV; |
403 | } | |
1da177e4 | 404 | |
52df6440 | 405 | /* Addresses cycling */ |
e76f67b5 | 406 | for (i = 8; i <= 248; i += 40) { |
52df6440 | 407 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf |
e76f67b5 JD |
408 | || i2c_smbus_read_byte_data(new_client, i + 2) != hyst |
409 | || i2c_smbus_read_byte_data(new_client, i + 3) != os) | |
52df6440 | 410 | return -ENODEV; |
05e82fe4 LS |
411 | if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) |
412 | != LM75A_ID) | |
413 | return -ENODEV; | |
1da177e4 LT |
414 | } |
415 | ||
05e82fe4 | 416 | strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); |
c1685f61 | 417 | |
1da177e4 | 418 | return 0; |
01a52397 DB |
419 | } |
420 | ||
9914518e SD |
421 | #ifdef CONFIG_PM |
422 | static int lm75_suspend(struct device *dev) | |
423 | { | |
424 | int status; | |
425 | struct i2c_client *client = to_i2c_client(dev); | |
426 | status = lm75_read_value(client, LM75_REG_CONF); | |
427 | if (status < 0) { | |
428 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
429 | return status; | |
430 | } | |
431 | status = status | LM75_SHUTDOWN; | |
432 | lm75_write_value(client, LM75_REG_CONF, status); | |
433 | return 0; | |
434 | } | |
435 | ||
436 | static int lm75_resume(struct device *dev) | |
437 | { | |
438 | int status; | |
439 | struct i2c_client *client = to_i2c_client(dev); | |
440 | status = lm75_read_value(client, LM75_REG_CONF); | |
441 | if (status < 0) { | |
442 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
443 | return status; | |
444 | } | |
445 | status = status & ~LM75_SHUTDOWN; | |
446 | lm75_write_value(client, LM75_REG_CONF, status); | |
447 | return 0; | |
448 | } | |
449 | ||
450 | static const struct dev_pm_ops lm75_dev_pm_ops = { | |
451 | .suspend = lm75_suspend, | |
452 | .resume = lm75_resume, | |
453 | }; | |
454 | #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops) | |
455 | #else | |
456 | #define LM75_DEV_PM_OPS NULL | |
457 | #endif /* CONFIG_PM */ | |
458 | ||
8ff69eeb JD |
459 | static struct i2c_driver lm75_driver = { |
460 | .class = I2C_CLASS_HWMON, | |
01a52397 | 461 | .driver = { |
8ff69eeb | 462 | .name = "lm75", |
9914518e | 463 | .pm = LM75_DEV_PM_OPS, |
01a52397 | 464 | }, |
8ff69eeb JD |
465 | .probe = lm75_probe, |
466 | .remove = lm75_remove, | |
467 | .id_table = lm75_ids, | |
468 | .detect = lm75_detect, | |
c3813d6a | 469 | .address_list = normal_i2c, |
01a52397 DB |
470 | }; |
471 | ||
472 | /*-----------------------------------------------------------------------*/ | |
473 | ||
474 | /* register access */ | |
475 | ||
caaa0f36 S |
476 | /* |
477 | * All registers are word-sized, except for the configuration register. | |
478 | * LM75 uses a high-byte first convention, which is exactly opposite to | |
479 | * the SMBus standard. | |
480 | */ | |
1da177e4 LT |
481 | static int lm75_read_value(struct i2c_client *client, u8 reg) |
482 | { | |
483 | if (reg == LM75_REG_CONF) | |
484 | return i2c_smbus_read_byte_data(client, reg); | |
90f4102c JD |
485 | else |
486 | return i2c_smbus_read_word_swapped(client, reg); | |
1da177e4 LT |
487 | } |
488 | ||
1da177e4 LT |
489 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) |
490 | { | |
491 | if (reg == LM75_REG_CONF) | |
492 | return i2c_smbus_write_byte_data(client, reg, value); | |
493 | else | |
90f4102c | 494 | return i2c_smbus_write_word_swapped(client, reg, value); |
1da177e4 LT |
495 | } |
496 | ||
1da177e4 LT |
497 | static struct lm75_data *lm75_update_device(struct device *dev) |
498 | { | |
d663ec49 GR |
499 | struct lm75_data *data = dev_get_drvdata(dev); |
500 | struct i2c_client *client = data->client; | |
1f962f36 | 501 | struct lm75_data *ret = data; |
1da177e4 | 502 | |
9a61bf63 | 503 | mutex_lock(&data->update_lock); |
1da177e4 | 504 | |
87d0621a | 505 | if (time_after(jiffies, data->last_updated + data->sample_time) |
1da177e4 | 506 | || !data->valid) { |
9ca8e40c | 507 | int i; |
1da177e4 LT |
508 | dev_dbg(&client->dev, "Starting lm75 update\n"); |
509 | ||
bcccc3a2 DB |
510 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) { |
511 | int status; | |
512 | ||
513 | status = lm75_read_value(client, LM75_REG_TEMP[i]); | |
1f962f36 FM |
514 | if (unlikely(status < 0)) { |
515 | dev_dbg(dev, | |
516 | "LM75: Failed to read value: reg %d, error %d\n", | |
517 | LM75_REG_TEMP[i], status); | |
518 | ret = ERR_PTR(status); | |
519 | data->valid = 0; | |
520 | goto abort; | |
521 | } | |
522 | data->temp[i] = status; | |
bcccc3a2 | 523 | } |
1da177e4 LT |
524 | data->last_updated = jiffies; |
525 | data->valid = 1; | |
526 | } | |
527 | ||
1f962f36 | 528 | abort: |
9a61bf63 | 529 | mutex_unlock(&data->update_lock); |
1f962f36 | 530 | return ret; |
1da177e4 LT |
531 | } |
532 | ||
f0967eea | 533 | module_i2c_driver(lm75_driver); |
1da177e4 LT |
534 | |
535 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
536 | MODULE_DESCRIPTION("LM75 driver"); | |
537 | MODULE_LICENSE("GPL"); |