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Commit | Line | Data |
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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> |
e97a45f1 | 29 | #include <linux/of_device.h> |
22e73183 | 30 | #include <linux/of.h> |
e65365fe | 31 | #include <linux/regmap.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 | 46 | lm75a, |
799fc602 | 47 | lm75b, |
9ebd3d82 DB |
48 | max6625, |
49 | max6626, | |
50 | mcp980x, | |
51 | stds75, | |
52 | tcn75, | |
53 | tmp100, | |
54 | tmp101, | |
6d034059 | 55 | tmp105, |
c83959f8 | 56 | tmp112, |
9ebd3d82 DB |
57 | tmp175, |
58 | tmp275, | |
59 | tmp75, | |
9c32e815 | 60 | tmp75c, |
9ebd3d82 DB |
61 | }; |
62 | ||
8ff69eeb | 63 | /* Addresses scanned */ |
25e9c86d | 64 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
1da177e4 | 65 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
1da177e4 | 66 | |
1da177e4 LT |
67 | |
68 | /* The LM75 registers */ | |
e65365fe | 69 | #define LM75_REG_TEMP 0x00 |
1da177e4 | 70 | #define LM75_REG_CONF 0x01 |
e65365fe GR |
71 | #define LM75_REG_HYST 0x02 |
72 | #define LM75_REG_MAX 0x03 | |
1da177e4 LT |
73 | |
74 | /* Each client has this additional data */ | |
75 | struct lm75_data { | |
d663ec49 | 76 | struct i2c_client *client; |
e65365fe | 77 | struct regmap *regmap; |
9ebd3d82 | 78 | u8 orig_conf; |
87d0621a JD |
79 | u8 resolution; /* In bits, between 9 and 12 */ |
80 | u8 resolution_limits; | |
e65365fe | 81 | unsigned int sample_time; /* In ms */ |
1da177e4 LT |
82 | }; |
83 | ||
01a52397 DB |
84 | /*-----------------------------------------------------------------------*/ |
85 | ||
22e73183 EV |
86 | static inline long lm75_reg_to_mc(s16 temp, u8 resolution) |
87 | { | |
88 | return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8); | |
89 | } | |
90 | ||
08b02433 GR |
91 | static int lm75_read(struct device *dev, enum hwmon_sensor_types type, |
92 | u32 attr, int channel, long *val) | |
22e73183 | 93 | { |
e65365fe | 94 | struct lm75_data *data = dev_get_drvdata(dev); |
08b02433 GR |
95 | unsigned int regval; |
96 | int err, reg; | |
97 | ||
98 | switch (type) { | |
99 | case hwmon_chip: | |
100 | switch (attr) { | |
101 | case hwmon_chip_update_interval: | |
102 | *val = data->sample_time; | |
103 | break;; | |
104 | default: | |
105 | return -EINVAL; | |
106 | } | |
107 | break; | |
108 | case hwmon_temp: | |
109 | switch (attr) { | |
110 | case hwmon_temp_input: | |
111 | reg = LM75_REG_TEMP; | |
112 | break; | |
113 | case hwmon_temp_max: | |
114 | reg = LM75_REG_MAX; | |
115 | break; | |
116 | case hwmon_temp_max_hyst: | |
117 | reg = LM75_REG_HYST; | |
118 | break; | |
119 | default: | |
120 | return -EINVAL; | |
121 | } | |
122 | err = regmap_read(data->regmap, reg, ®val); | |
123 | if (err < 0) | |
124 | return err; | |
125 | ||
126 | *val = lm75_reg_to_mc(regval, data->resolution); | |
127 | break; | |
128 | default: | |
129 | return -EINVAL; | |
130 | } | |
22e73183 EV |
131 | return 0; |
132 | } | |
133 | ||
08b02433 GR |
134 | static int lm75_write(struct device *dev, enum hwmon_sensor_types type, |
135 | u32 attr, int channel, long temp) | |
9ca8e40c | 136 | { |
e65365fe | 137 | struct lm75_data *data = dev_get_drvdata(dev); |
87d0621a | 138 | u8 resolution; |
08b02433 GR |
139 | int reg; |
140 | ||
141 | if (type != hwmon_temp) | |
142 | return -EINVAL; | |
e3cd9528 | 143 | |
08b02433 GR |
144 | switch (attr) { |
145 | case hwmon_temp_max: | |
146 | reg = LM75_REG_MAX; | |
147 | break; | |
148 | case hwmon_temp_max_hyst: | |
149 | reg = LM75_REG_HYST; | |
150 | break; | |
151 | default: | |
152 | return -EINVAL; | |
153 | } | |
9ca8e40c | 154 | |
87d0621a JD |
155 | /* |
156 | * Resolution of limit registers is assumed to be the same as the | |
157 | * temperature input register resolution unless given explicitly. | |
158 | */ | |
08b02433 | 159 | if (data->resolution_limits) |
87d0621a JD |
160 | resolution = data->resolution_limits; |
161 | else | |
162 | resolution = data->resolution; | |
163 | ||
87d0621a | 164 | temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); |
e65365fe GR |
165 | temp = DIV_ROUND_CLOSEST(temp << (resolution - 8), |
166 | 1000) << (16 - resolution); | |
e65365fe | 167 | |
08b02433 | 168 | return regmap_write(data->regmap, reg, temp); |
1da177e4 | 169 | } |
1da177e4 | 170 | |
08b02433 GR |
171 | static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type, |
172 | u32 attr, int channel) | |
5f7e5e29 | 173 | { |
08b02433 GR |
174 | switch (type) { |
175 | case hwmon_chip: | |
176 | switch (attr) { | |
177 | case hwmon_chip_update_interval: | |
178 | return S_IRUGO; | |
179 | } | |
180 | break; | |
181 | case hwmon_temp: | |
182 | switch (attr) { | |
183 | case hwmon_temp_input: | |
184 | return S_IRUGO; | |
185 | case hwmon_temp_max: | |
186 | case hwmon_temp_max_hyst: | |
187 | return S_IRUGO | S_IWUSR; | |
188 | } | |
189 | break; | |
190 | default: | |
191 | break; | |
192 | } | |
193 | return 0; | |
5f7e5e29 GR |
194 | } |
195 | ||
08b02433 | 196 | /*-----------------------------------------------------------------------*/ |
1da177e4 | 197 | |
08b02433 | 198 | /* device probe and removal */ |
c1685f61 | 199 | |
08b02433 GR |
200 | /* chip configuration */ |
201 | ||
202 | static const u32 lm75_chip_config[] = { | |
203 | HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL, | |
204 | 0 | |
c1685f61 | 205 | }; |
c1685f61 | 206 | |
08b02433 GR |
207 | static const struct hwmon_channel_info lm75_chip = { |
208 | .type = hwmon_chip, | |
209 | .config = lm75_chip_config, | |
2251aef6 EV |
210 | }; |
211 | ||
08b02433 GR |
212 | static const u32 lm75_temp_config[] = { |
213 | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, | |
214 | 0 | |
215 | }; | |
01a52397 | 216 | |
08b02433 GR |
217 | static const struct hwmon_channel_info lm75_temp = { |
218 | .type = hwmon_temp, | |
219 | .config = lm75_temp_config, | |
220 | }; | |
221 | ||
222 | static const struct hwmon_channel_info *lm75_info[] = { | |
223 | &lm75_chip, | |
224 | &lm75_temp, | |
225 | NULL | |
226 | }; | |
227 | ||
228 | static const struct hwmon_ops lm75_hwmon_ops = { | |
229 | .is_visible = lm75_is_visible, | |
230 | .read = lm75_read, | |
231 | .write = lm75_write, | |
232 | }; | |
233 | ||
234 | static const struct hwmon_chip_info lm75_chip_info = { | |
235 | .ops = &lm75_hwmon_ops, | |
236 | .info = lm75_info, | |
237 | }; | |
9ebd3d82 | 238 | |
e65365fe GR |
239 | static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg) |
240 | { | |
241 | return reg != LM75_REG_TEMP; | |
242 | } | |
243 | ||
244 | static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg) | |
245 | { | |
246 | return reg == LM75_REG_TEMP; | |
247 | } | |
248 | ||
249 | static const struct regmap_config lm75_regmap_config = { | |
250 | .reg_bits = 8, | |
251 | .val_bits = 16, | |
252 | .max_register = LM75_REG_MAX, | |
253 | .writeable_reg = lm75_is_writeable_reg, | |
254 | .volatile_reg = lm75_is_volatile_reg, | |
255 | .val_format_endian = REGMAP_ENDIAN_BIG, | |
256 | .cache_type = REGCACHE_RBTREE, | |
257 | .use_single_rw = true, | |
258 | }; | |
259 | ||
9e37d3e2 GR |
260 | static void lm75_remove(void *data) |
261 | { | |
262 | struct lm75_data *lm75 = data; | |
263 | struct i2c_client *client = lm75->client; | |
264 | ||
265 | i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf); | |
266 | } | |
267 | ||
9ebd3d82 DB |
268 | static int |
269 | lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
270 | { | |
d663ec49 | 271 | struct device *dev = &client->dev; |
9e37d3e2 | 272 | struct device *hwmon_dev; |
9ebd3d82 | 273 | struct lm75_data *data; |
90e2b545 | 274 | int status, err; |
9ebd3d82 DB |
275 | u8 set_mask, clr_mask; |
276 | int new; | |
e97a45f1 JMC |
277 | enum lm75_type kind; |
278 | ||
279 | if (client->dev.of_node) | |
280 | kind = (enum lm75_type)of_device_get_match_data(&client->dev); | |
281 | else | |
282 | kind = id->driver_data; | |
9ebd3d82 DB |
283 | |
284 | if (!i2c_check_functionality(client->adapter, | |
285 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) | |
286 | return -EIO; | |
287 | ||
d663ec49 | 288 | data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL); |
9ebd3d82 DB |
289 | if (!data) |
290 | return -ENOMEM; | |
291 | ||
d663ec49 | 292 | data->client = client; |
e65365fe GR |
293 | |
294 | data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config); | |
295 | if (IS_ERR(data->regmap)) | |
296 | return PTR_ERR(data->regmap); | |
9ebd3d82 DB |
297 | |
298 | /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. | |
299 | * Then tweak to be more precise when appropriate. | |
300 | */ | |
301 | set_mask = 0; | |
8a5c5cc6 JD |
302 | clr_mask = LM75_SHUTDOWN; /* continuous conversions */ |
303 | ||
0cd2c72d | 304 | switch (kind) { |
8a5c5cc6 JD |
305 | case adt75: |
306 | clr_mask |= 1 << 5; /* not one-shot mode */ | |
0cd2c72d | 307 | data->resolution = 12; |
e65365fe | 308 | data->sample_time = MSEC_PER_SEC / 8; |
8a5c5cc6 JD |
309 | break; |
310 | case ds1775: | |
311 | case ds75: | |
312 | case stds75: | |
0cd2c72d JD |
313 | clr_mask |= 3 << 5; |
314 | set_mask |= 2 << 5; /* 11-bit mode */ | |
315 | data->resolution = 11; | |
e65365fe | 316 | data->sample_time = MSEC_PER_SEC; |
0cd2c72d | 317 | break; |
3fbc81e3 JD |
318 | case ds7505: |
319 | set_mask |= 3 << 5; /* 12-bit mode */ | |
320 | data->resolution = 12; | |
e65365fe | 321 | data->sample_time = MSEC_PER_SEC / 4; |
3fbc81e3 | 322 | break; |
c98d6c65 | 323 | case g751: |
0cd2c72d JD |
324 | case lm75: |
325 | case lm75a: | |
326 | data->resolution = 9; | |
e65365fe | 327 | data->sample_time = MSEC_PER_SEC / 2; |
0cd2c72d | 328 | break; |
799fc602 MT |
329 | case lm75b: |
330 | data->resolution = 11; | |
e65365fe | 331 | data->sample_time = MSEC_PER_SEC / 4; |
799fc602 | 332 | break; |
0cd2c72d JD |
333 | case max6625: |
334 | data->resolution = 9; | |
e65365fe | 335 | data->sample_time = MSEC_PER_SEC / 4; |
0cd2c72d JD |
336 | break; |
337 | case max6626: | |
338 | data->resolution = 12; | |
339 | data->resolution_limits = 9; | |
e65365fe | 340 | data->sample_time = MSEC_PER_SEC / 4; |
0cd2c72d JD |
341 | break; |
342 | case tcn75: | |
343 | data->resolution = 9; | |
e65365fe | 344 | data->sample_time = MSEC_PER_SEC / 8; |
8a5c5cc6 JD |
345 | break; |
346 | case mcp980x: | |
0cd2c72d JD |
347 | data->resolution_limits = 9; |
348 | /* fall through */ | |
8a5c5cc6 JD |
349 | case tmp100: |
350 | case tmp101: | |
0cd2c72d JD |
351 | set_mask |= 3 << 5; /* 12-bit mode */ |
352 | data->resolution = 12; | |
e65365fe | 353 | data->sample_time = MSEC_PER_SEC; |
0cd2c72d JD |
354 | clr_mask |= 1 << 7; /* not one-shot mode */ |
355 | break; | |
c83959f8 FK |
356 | case tmp112: |
357 | set_mask |= 3 << 5; /* 12-bit mode */ | |
358 | clr_mask |= 1 << 7; /* not one-shot mode */ | |
359 | data->resolution = 12; | |
e65365fe | 360 | data->sample_time = MSEC_PER_SEC / 4; |
c83959f8 | 361 | break; |
8a5c5cc6 JD |
362 | case tmp105: |
363 | case tmp175: | |
364 | case tmp275: | |
365 | case tmp75: | |
0cd2c72d | 366 | set_mask |= 3 << 5; /* 12-bit mode */ |
8a5c5cc6 | 367 | clr_mask |= 1 << 7; /* not one-shot mode */ |
0cd2c72d | 368 | data->resolution = 12; |
e65365fe | 369 | data->sample_time = MSEC_PER_SEC / 2; |
8a5c5cc6 | 370 | break; |
9c32e815 BG |
371 | case tmp75c: |
372 | clr_mask |= 1 << 5; /* not one-shot mode */ | |
373 | data->resolution = 12; | |
e65365fe | 374 | data->sample_time = MSEC_PER_SEC / 4; |
9c32e815 | 375 | break; |
8a5c5cc6 | 376 | } |
9ebd3d82 DB |
377 | |
378 | /* configure as specified */ | |
38aefb41 | 379 | status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); |
9ebd3d82 | 380 | if (status < 0) { |
d663ec49 | 381 | dev_dbg(dev, "Can't read config? %d\n", status); |
13ac7a01 | 382 | return status; |
9ebd3d82 DB |
383 | } |
384 | data->orig_conf = status; | |
385 | new = status & ~clr_mask; | |
386 | new |= set_mask; | |
387 | if (status != new) | |
38aefb41 | 388 | i2c_smbus_write_byte_data(client, LM75_REG_CONF, new); |
9ebd3d82 | 389 | |
90e2b545 GR |
390 | err = devm_add_action_or_reset(dev, lm75_remove, data); |
391 | if (err) | |
392 | return err; | |
9ebd3d82 | 393 | |
9e37d3e2 | 394 | dev_dbg(dev, "Config %02x\n", new); |
22e73183 | 395 | |
08b02433 GR |
396 | hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, |
397 | data, &lm75_chip_info, | |
398 | NULL); | |
9e37d3e2 GR |
399 | if (IS_ERR(hwmon_dev)) |
400 | return PTR_ERR(hwmon_dev); | |
9ebd3d82 | 401 | |
9e37d3e2 | 402 | dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name); |
9ebd3d82 | 403 | |
9ebd3d82 DB |
404 | return 0; |
405 | } | |
406 | ||
407 | static const struct i2c_device_id lm75_ids[] = { | |
e96f9d89 | 408 | { "adt75", adt75, }, |
9ebd3d82 DB |
409 | { "ds1775", ds1775, }, |
410 | { "ds75", ds75, }, | |
3fbc81e3 | 411 | { "ds7505", ds7505, }, |
c98d6c65 | 412 | { "g751", g751, }, |
9ebd3d82 DB |
413 | { "lm75", lm75, }, |
414 | { "lm75a", lm75a, }, | |
799fc602 | 415 | { "lm75b", lm75b, }, |
9ebd3d82 DB |
416 | { "max6625", max6625, }, |
417 | { "max6626", max6626, }, | |
418 | { "mcp980x", mcp980x, }, | |
419 | { "stds75", stds75, }, | |
420 | { "tcn75", tcn75, }, | |
421 | { "tmp100", tmp100, }, | |
422 | { "tmp101", tmp101, }, | |
6d034059 | 423 | { "tmp105", tmp105, }, |
c83959f8 | 424 | { "tmp112", tmp112, }, |
9ebd3d82 DB |
425 | { "tmp175", tmp175, }, |
426 | { "tmp275", tmp275, }, | |
427 | { "tmp75", tmp75, }, | |
9c32e815 | 428 | { "tmp75c", tmp75c, }, |
9ebd3d82 DB |
429 | { /* LIST END */ } |
430 | }; | |
431 | MODULE_DEVICE_TABLE(i2c, lm75_ids); | |
432 | ||
e97a45f1 JMC |
433 | static const struct of_device_id lm75_of_match[] = { |
434 | { | |
435 | .compatible = "adi,adt75", | |
436 | .data = (void *)adt75 | |
437 | }, | |
438 | { | |
439 | .compatible = "dallas,ds1775", | |
440 | .data = (void *)ds1775 | |
441 | }, | |
442 | { | |
443 | .compatible = "dallas,ds75", | |
444 | .data = (void *)ds75 | |
445 | }, | |
446 | { | |
447 | .compatible = "dallas,ds7505", | |
448 | .data = (void *)ds7505 | |
449 | }, | |
450 | { | |
451 | .compatible = "gmt,g751", | |
452 | .data = (void *)g751 | |
453 | }, | |
454 | { | |
455 | .compatible = "national,lm75", | |
456 | .data = (void *)lm75 | |
457 | }, | |
458 | { | |
459 | .compatible = "national,lm75a", | |
460 | .data = (void *)lm75a | |
461 | }, | |
462 | { | |
463 | .compatible = "national,lm75b", | |
464 | .data = (void *)lm75b | |
465 | }, | |
466 | { | |
467 | .compatible = "maxim,max6625", | |
468 | .data = (void *)max6625 | |
469 | }, | |
470 | { | |
471 | .compatible = "maxim,max6626", | |
472 | .data = (void *)max6626 | |
473 | }, | |
474 | { | |
475 | .compatible = "maxim,mcp980x", | |
476 | .data = (void *)mcp980x | |
477 | }, | |
478 | { | |
479 | .compatible = "st,stds75", | |
480 | .data = (void *)stds75 | |
481 | }, | |
482 | { | |
483 | .compatible = "microchip,tcn75", | |
484 | .data = (void *)tcn75 | |
485 | }, | |
486 | { | |
487 | .compatible = "ti,tmp100", | |
488 | .data = (void *)tmp100 | |
489 | }, | |
490 | { | |
491 | .compatible = "ti,tmp101", | |
492 | .data = (void *)tmp101 | |
493 | }, | |
494 | { | |
495 | .compatible = "ti,tmp105", | |
496 | .data = (void *)tmp105 | |
497 | }, | |
498 | { | |
499 | .compatible = "ti,tmp112", | |
500 | .data = (void *)tmp112 | |
501 | }, | |
502 | { | |
503 | .compatible = "ti,tmp175", | |
504 | .data = (void *)tmp175 | |
505 | }, | |
506 | { | |
507 | .compatible = "ti,tmp275", | |
508 | .data = (void *)tmp275 | |
509 | }, | |
510 | { | |
511 | .compatible = "ti,tmp75", | |
512 | .data = (void *)tmp75 | |
513 | }, | |
514 | { | |
515 | .compatible = "ti,tmp75c", | |
516 | .data = (void *)tmp75c | |
517 | }, | |
518 | { }, | |
519 | }; | |
520 | MODULE_DEVICE_TABLE(of, lm75_of_match); | |
521 | ||
05e82fe4 LS |
522 | #define LM75A_ID 0xA1 |
523 | ||
8ff69eeb | 524 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 525 | static int lm75_detect(struct i2c_client *new_client, |
8ff69eeb | 526 | struct i2c_board_info *info) |
1da177e4 | 527 | { |
8ff69eeb | 528 | struct i2c_adapter *adapter = new_client->adapter; |
1da177e4 | 529 | int i; |
e76f67b5 | 530 | int conf, hyst, os; |
05e82fe4 | 531 | bool is_lm75a = 0; |
1da177e4 | 532 | |
1da177e4 LT |
533 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
534 | I2C_FUNC_SMBUS_WORD_DATA)) | |
8ff69eeb | 535 | return -ENODEV; |
1da177e4 | 536 | |
426343ef JD |
537 | /* |
538 | * Now, we do the remaining detection. There is no identification- | |
539 | * dedicated register so we have to rely on several tricks: | |
540 | * unused bits, registers cycling over 8-address boundaries, | |
541 | * addresses 0x04-0x07 returning the last read value. | |
542 | * The cycling+unused addresses combination is not tested, | |
543 | * since it would significantly slow the detection down and would | |
544 | * hardly add any value. | |
545 | * | |
546 | * The National Semiconductor LM75A is different than earlier | |
547 | * LM75s. It has an ID byte of 0xaX (where X is the chip | |
548 | * revision, with 1 being the only revision in existence) in | |
549 | * register 7, and unused registers return 0xff rather than the | |
550 | * last read value. | |
551 | * | |
552 | * Note that this function only detects the original National | |
553 | * Semiconductor LM75 and the LM75A. Clones from other vendors | |
554 | * aren't detected, on purpose, because they are typically never | |
555 | * found on PC hardware. They are found on embedded designs where | |
556 | * they can be instantiated explicitly so detection is not needed. | |
557 | * The absence of identification registers on all these clones | |
558 | * would make their exhaustive detection very difficult and weak, | |
559 | * and odds are that the driver would bind to unsupported devices. | |
560 | */ | |
1da177e4 | 561 | |
e76f67b5 | 562 | /* Unused bits */ |
52df6440 | 563 | conf = i2c_smbus_read_byte_data(new_client, 1); |
e76f67b5 JD |
564 | if (conf & 0xe0) |
565 | return -ENODEV; | |
05e82fe4 LS |
566 | |
567 | /* First check for LM75A */ | |
568 | if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { | |
569 | /* LM75A returns 0xff on unused registers so | |
570 | just to be sure we check for that too. */ | |
571 | if (i2c_smbus_read_byte_data(new_client, 4) != 0xff | |
572 | || i2c_smbus_read_byte_data(new_client, 5) != 0xff | |
573 | || i2c_smbus_read_byte_data(new_client, 6) != 0xff) | |
574 | return -ENODEV; | |
575 | is_lm75a = 1; | |
e76f67b5 JD |
576 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
577 | os = i2c_smbus_read_byte_data(new_client, 3); | |
05e82fe4 LS |
578 | } else { /* Traditional style LM75 detection */ |
579 | /* Unused addresses */ | |
e76f67b5 JD |
580 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
581 | if (i2c_smbus_read_byte_data(new_client, 4) != hyst | |
582 | || i2c_smbus_read_byte_data(new_client, 5) != hyst | |
583 | || i2c_smbus_read_byte_data(new_client, 6) != hyst | |
584 | || i2c_smbus_read_byte_data(new_client, 7) != hyst) | |
05e82fe4 | 585 | return -ENODEV; |
e76f67b5 JD |
586 | os = i2c_smbus_read_byte_data(new_client, 3); |
587 | if (i2c_smbus_read_byte_data(new_client, 4) != os | |
588 | || i2c_smbus_read_byte_data(new_client, 5) != os | |
589 | || i2c_smbus_read_byte_data(new_client, 6) != os | |
590 | || i2c_smbus_read_byte_data(new_client, 7) != os) | |
05e82fe4 LS |
591 | return -ENODEV; |
592 | } | |
4ad40cc5 GR |
593 | /* |
594 | * It is very unlikely that this is a LM75 if both | |
595 | * hysteresis and temperature limit registers are 0. | |
596 | */ | |
597 | if (hyst == 0 && os == 0) | |
598 | return -ENODEV; | |
1da177e4 | 599 | |
52df6440 | 600 | /* Addresses cycling */ |
e76f67b5 | 601 | for (i = 8; i <= 248; i += 40) { |
52df6440 | 602 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf |
e76f67b5 JD |
603 | || i2c_smbus_read_byte_data(new_client, i + 2) != hyst |
604 | || i2c_smbus_read_byte_data(new_client, i + 3) != os) | |
52df6440 | 605 | return -ENODEV; |
05e82fe4 LS |
606 | if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) |
607 | != LM75A_ID) | |
608 | return -ENODEV; | |
1da177e4 LT |
609 | } |
610 | ||
05e82fe4 | 611 | strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); |
c1685f61 | 612 | |
1da177e4 | 613 | return 0; |
01a52397 DB |
614 | } |
615 | ||
9914518e SD |
616 | #ifdef CONFIG_PM |
617 | static int lm75_suspend(struct device *dev) | |
618 | { | |
619 | int status; | |
620 | struct i2c_client *client = to_i2c_client(dev); | |
38aefb41 | 621 | status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); |
9914518e SD |
622 | if (status < 0) { |
623 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
624 | return status; | |
625 | } | |
626 | status = status | LM75_SHUTDOWN; | |
38aefb41 | 627 | i2c_smbus_write_byte_data(client, LM75_REG_CONF, status); |
9914518e SD |
628 | return 0; |
629 | } | |
630 | ||
631 | static int lm75_resume(struct device *dev) | |
632 | { | |
633 | int status; | |
634 | struct i2c_client *client = to_i2c_client(dev); | |
38aefb41 | 635 | status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); |
9914518e SD |
636 | if (status < 0) { |
637 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
638 | return status; | |
639 | } | |
640 | status = status & ~LM75_SHUTDOWN; | |
38aefb41 | 641 | i2c_smbus_write_byte_data(client, LM75_REG_CONF, status); |
9914518e SD |
642 | return 0; |
643 | } | |
644 | ||
645 | static const struct dev_pm_ops lm75_dev_pm_ops = { | |
646 | .suspend = lm75_suspend, | |
647 | .resume = lm75_resume, | |
648 | }; | |
649 | #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops) | |
650 | #else | |
651 | #define LM75_DEV_PM_OPS NULL | |
652 | #endif /* CONFIG_PM */ | |
653 | ||
8ff69eeb JD |
654 | static struct i2c_driver lm75_driver = { |
655 | .class = I2C_CLASS_HWMON, | |
01a52397 | 656 | .driver = { |
8ff69eeb | 657 | .name = "lm75", |
e97a45f1 | 658 | .of_match_table = of_match_ptr(lm75_of_match), |
9914518e | 659 | .pm = LM75_DEV_PM_OPS, |
01a52397 | 660 | }, |
8ff69eeb | 661 | .probe = lm75_probe, |
8ff69eeb JD |
662 | .id_table = lm75_ids, |
663 | .detect = lm75_detect, | |
c3813d6a | 664 | .address_list = normal_i2c, |
01a52397 DB |
665 | }; |
666 | ||
f0967eea | 667 | module_i2c_driver(lm75_driver); |
1da177e4 LT |
668 | |
669 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
670 | MODULE_DESCRIPTION("LM75 driver"); | |
671 | MODULE_LICENSE("GPL"); |