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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * lm75.c - Part of lm_sensors, Linux kernel modules for hardware
4 * monitoring
5 * Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
6 */
7
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/jiffies.h>
12#include <linux/i2c.h>
13#include <linux/hwmon.h>
14#include <linux/hwmon-sysfs.h>
15#include <linux/err.h>
16#include <linux/of_device.h>
17#include <linux/of.h>
18#include <linux/regmap.h>
19#include <linux/util_macros.h>
20#include <linux/regulator/consumer.h>
21#include "lm75.h"
22
23/*
24 * This driver handles the LM75 and compatible digital temperature sensors.
25 */
26
27enum lm75_type { /* keep sorted in alphabetical order */
28 adt75,
29 at30ts74,
30 ds1775,
31 ds75,
32 ds7505,
33 g751,
34 lm75,
35 lm75a,
36 lm75b,
37 max6625,
38 max6626,
39 max31725,
40 mcp980x,
41 pct2075,
42 stds75,
43 stlm75,
44 tcn75,
45 tmp100,
46 tmp101,
47 tmp105,
48 tmp112,
49 tmp175,
50 tmp275,
51 tmp75,
52 tmp75b,
53 tmp75c,
54 tmp1075,
55};
56
57/**
58 * struct lm75_params - lm75 configuration parameters.
59 * @set_mask: Bits to set in configuration register when configuring
60 * the chip.
61 * @clr_mask: Bits to clear in configuration register when configuring
62 * the chip.
63 * @default_resolution: Default number of bits to represent the temperature
64 * value.
65 * @resolution_limits: Limit register resolution. Optional. Should be set if
66 * the resolution of limit registers does not match the
67 * resolution of the temperature register.
68 * @resolutions: List of resolutions associated with sample times.
69 * Optional. Should be set if num_sample_times is larger
70 * than 1, and if the resolution changes with sample times.
71 * If set, number of entries must match num_sample_times.
72 * @default_sample_time:Sample time to be set by default.
73 * @num_sample_times: Number of possible sample times to be set. Optional.
74 * Should be set if the number of sample times is larger
75 * than one.
76 * @sample_times: All the possible sample times to be set. Mandatory if
77 * num_sample_times is larger than 1. If set, number of
78 * entries must match num_sample_times.
79 */
80
81struct lm75_params {
82 u8 set_mask;
83 u8 clr_mask;
84 u8 default_resolution;
85 u8 resolution_limits;
86 const u8 *resolutions;
87 unsigned int default_sample_time;
88 u8 num_sample_times;
89 const unsigned int *sample_times;
90};
91
92/* Addresses scanned */
93static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
94 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
95
96/* The LM75 registers */
97#define LM75_REG_TEMP 0x00
98#define LM75_REG_CONF 0x01
99#define LM75_REG_HYST 0x02
100#define LM75_REG_MAX 0x03
101#define PCT2075_REG_IDLE 0x04
102
103/* Each client has this additional data */
104struct lm75_data {
105 struct i2c_client *client;
106 struct regmap *regmap;
107 struct regulator *vs;
108 u8 orig_conf;
109 u8 current_conf;
110 u8 resolution; /* In bits, 9 to 16 */
111 unsigned int sample_time; /* In ms */
112 enum lm75_type kind;
113 const struct lm75_params *params;
114};
115
116/*-----------------------------------------------------------------------*/
117
118static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };
119
120#define LM75_SAMPLE_CLEAR_MASK (3 << 5)
121
122/* The structure below stores the configuration values of the supported devices.
123 * In case of being supported multiple configurations, the default one must
124 * always be the first element of the array
125 */
126static const struct lm75_params device_params[] = {
127 [adt75] = {
128 .clr_mask = 1 << 5, /* not one-shot mode */
129 .default_resolution = 12,
130 .default_sample_time = MSEC_PER_SEC / 10,
131 },
132 [at30ts74] = {
133 .set_mask = 3 << 5, /* 12-bit mode*/
134 .default_resolution = 12,
135 .default_sample_time = 200,
136 .num_sample_times = 4,
137 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
138 .resolutions = (u8 []) {9, 10, 11, 12 },
139 },
140 [ds1775] = {
141 .clr_mask = 3 << 5,
142 .set_mask = 2 << 5, /* 11-bit mode */
143 .default_resolution = 11,
144 .default_sample_time = 500,
145 .num_sample_times = 4,
146 .sample_times = (unsigned int []){ 125, 250, 500, 1000 },
147 .resolutions = (u8 []) {9, 10, 11, 12 },
148 },
149 [ds75] = {
150 .clr_mask = 3 << 5,
151 .set_mask = 2 << 5, /* 11-bit mode */
152 .default_resolution = 11,
153 .default_sample_time = 600,
154 .num_sample_times = 4,
155 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
156 .resolutions = (u8 []) {9, 10, 11, 12 },
157 },
158 [stds75] = {
159 .clr_mask = 3 << 5,
160 .set_mask = 2 << 5, /* 11-bit mode */
161 .default_resolution = 11,
162 .default_sample_time = 600,
163 .num_sample_times = 4,
164 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
165 .resolutions = (u8 []) {9, 10, 11, 12 },
166 },
167 [stlm75] = {
168 .default_resolution = 9,
169 .default_sample_time = MSEC_PER_SEC / 6,
170 },
171 [ds7505] = {
172 .set_mask = 3 << 5, /* 12-bit mode*/
173 .default_resolution = 12,
174 .default_sample_time = 200,
175 .num_sample_times = 4,
176 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
177 .resolutions = (u8 []) {9, 10, 11, 12 },
178 },
179 [g751] = {
180 .default_resolution = 9,
181 .default_sample_time = MSEC_PER_SEC / 10,
182 },
183 [lm75] = {
184 .default_resolution = 9,
185 .default_sample_time = MSEC_PER_SEC / 10,
186 },
187 [lm75a] = {
188 .default_resolution = 9,
189 .default_sample_time = MSEC_PER_SEC / 10,
190 },
191 [lm75b] = {
192 .default_resolution = 11,
193 .default_sample_time = MSEC_PER_SEC / 10,
194 },
195 [max6625] = {
196 .default_resolution = 9,
197 .default_sample_time = MSEC_PER_SEC / 7,
198 },
199 [max6626] = {
200 .default_resolution = 12,
201 .default_sample_time = MSEC_PER_SEC / 7,
202 .resolution_limits = 9,
203 },
204 [max31725] = {
205 .default_resolution = 16,
206 .default_sample_time = MSEC_PER_SEC / 20,
207 },
208 [tcn75] = {
209 .default_resolution = 9,
210 .default_sample_time = MSEC_PER_SEC / 18,
211 },
212 [pct2075] = {
213 .default_resolution = 11,
214 .default_sample_time = MSEC_PER_SEC / 10,
215 .num_sample_times = 31,
216 .sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600,
217 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700,
218 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700,
219 2800, 2900, 3000, 3100 },
220 },
221 [mcp980x] = {
222 .set_mask = 3 << 5, /* 12-bit mode */
223 .clr_mask = 1 << 7, /* not one-shot mode */
224 .default_resolution = 12,
225 .resolution_limits = 9,
226 .default_sample_time = 240,
227 .num_sample_times = 4,
228 .sample_times = (unsigned int []){ 30, 60, 120, 240 },
229 .resolutions = (u8 []) {9, 10, 11, 12 },
230 },
231 [tmp100] = {
232 .set_mask = 3 << 5, /* 12-bit mode */
233 .clr_mask = 1 << 7, /* not one-shot mode */
234 .default_resolution = 12,
235 .default_sample_time = 320,
236 .num_sample_times = 4,
237 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
238 .resolutions = (u8 []) {9, 10, 11, 12 },
239 },
240 [tmp101] = {
241 .set_mask = 3 << 5, /* 12-bit mode */
242 .clr_mask = 1 << 7, /* not one-shot mode */
243 .default_resolution = 12,
244 .default_sample_time = 320,
245 .num_sample_times = 4,
246 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
247 .resolutions = (u8 []) {9, 10, 11, 12 },
248 },
249 [tmp105] = {
250 .set_mask = 3 << 5, /* 12-bit mode */
251 .clr_mask = 1 << 7, /* not one-shot mode*/
252 .default_resolution = 12,
253 .default_sample_time = 220,
254 .num_sample_times = 4,
255 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
256 .resolutions = (u8 []) {9, 10, 11, 12 },
257 },
258 [tmp112] = {
259 .set_mask = 3 << 5, /* 8 samples / second */
260 .clr_mask = 1 << 7, /* no one-shot mode*/
261 .default_resolution = 12,
262 .default_sample_time = 125,
263 .num_sample_times = 4,
264 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
265 },
266 [tmp175] = {
267 .set_mask = 3 << 5, /* 12-bit mode */
268 .clr_mask = 1 << 7, /* not one-shot mode*/
269 .default_resolution = 12,
270 .default_sample_time = 220,
271 .num_sample_times = 4,
272 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
273 .resolutions = (u8 []) {9, 10, 11, 12 },
274 },
275 [tmp275] = {
276 .set_mask = 3 << 5, /* 12-bit mode */
277 .clr_mask = 1 << 7, /* not one-shot mode*/
278 .default_resolution = 12,
279 .default_sample_time = 220,
280 .num_sample_times = 4,
281 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
282 .resolutions = (u8 []) {9, 10, 11, 12 },
283 },
284 [tmp75] = {
285 .set_mask = 3 << 5, /* 12-bit mode */
286 .clr_mask = 1 << 7, /* not one-shot mode*/
287 .default_resolution = 12,
288 .default_sample_time = 220,
289 .num_sample_times = 4,
290 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
291 .resolutions = (u8 []) {9, 10, 11, 12 },
292 },
293 [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */
294 .clr_mask = 1 << 7 | 3 << 5,
295 .default_resolution = 12,
296 .default_sample_time = MSEC_PER_SEC / 37,
297 .sample_times = (unsigned int []){ MSEC_PER_SEC / 37,
298 MSEC_PER_SEC / 18,
299 MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 },
300 .num_sample_times = 4,
301 },
302 [tmp75c] = {
303 .clr_mask = 1 << 5, /*not one-shot mode*/
304 .default_resolution = 12,
305 .default_sample_time = MSEC_PER_SEC / 12,
306 },
307 [tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */
308 .clr_mask = 1 << 5 | 1 << 6 | 1 << 7,
309 .default_resolution = 12,
310 .default_sample_time = 28,
311 .num_sample_times = 4,
312 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
313 }
314};
315
316static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
317{
318 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
319}
320
321static int lm75_write_config(struct lm75_data *data, u8 set_mask,
322 u8 clr_mask)
323{
324 u8 value;
325
326 clr_mask |= LM75_SHUTDOWN;
327 value = data->current_conf & ~clr_mask;
328 value |= set_mask;
329
330 if (data->current_conf != value) {
331 s32 err;
332
333 err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF,
334 value);
335 if (err)
336 return err;
337 data->current_conf = value;
338 }
339 return 0;
340}
341
342static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
343 u32 attr, int channel, long *val)
344{
345 struct lm75_data *data = dev_get_drvdata(dev);
346 unsigned int regval;
347 int err, reg;
348
349 switch (type) {
350 case hwmon_chip:
351 switch (attr) {
352 case hwmon_chip_update_interval:
353 *val = data->sample_time;
354 break;
355 default:
356 return -EINVAL;
357 }
358 break;
359 case hwmon_temp:
360 switch (attr) {
361 case hwmon_temp_input:
362 reg = LM75_REG_TEMP;
363 break;
364 case hwmon_temp_max:
365 reg = LM75_REG_MAX;
366 break;
367 case hwmon_temp_max_hyst:
368 reg = LM75_REG_HYST;
369 break;
370 default:
371 return -EINVAL;
372 }
373 err = regmap_read(data->regmap, reg, ®val);
374 if (err < 0)
375 return err;
376
377 *val = lm75_reg_to_mc(regval, data->resolution);
378 break;
379 default:
380 return -EINVAL;
381 }
382 return 0;
383}
384
385static int lm75_write_temp(struct device *dev, u32 attr, long temp)
386{
387 struct lm75_data *data = dev_get_drvdata(dev);
388 u8 resolution;
389 int reg;
390
391 switch (attr) {
392 case hwmon_temp_max:
393 reg = LM75_REG_MAX;
394 break;
395 case hwmon_temp_max_hyst:
396 reg = LM75_REG_HYST;
397 break;
398 default:
399 return -EINVAL;
400 }
401
402 /*
403 * Resolution of limit registers is assumed to be the same as the
404 * temperature input register resolution unless given explicitly.
405 */
406 if (data->params->resolution_limits)
407 resolution = data->params->resolution_limits;
408 else
409 resolution = data->resolution;
410
411 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
412 temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
413 1000) << (16 - resolution);
414
415 return regmap_write(data->regmap, reg, (u16)temp);
416}
417
418static int lm75_update_interval(struct device *dev, long val)
419{
420 struct lm75_data *data = dev_get_drvdata(dev);
421 unsigned int reg;
422 u8 index;
423 s32 err;
424
425 index = find_closest(val, data->params->sample_times,
426 (int)data->params->num_sample_times);
427
428 switch (data->kind) {
429 default:
430 err = lm75_write_config(data, lm75_sample_set_masks[index],
431 LM75_SAMPLE_CLEAR_MASK);
432 if (err)
433 return err;
434
435 data->sample_time = data->params->sample_times[index];
436 if (data->params->resolutions)
437 data->resolution = data->params->resolutions[index];
438 break;
439 case tmp112:
440 err = regmap_read(data->regmap, LM75_REG_CONF, ®);
441 if (err < 0)
442 return err;
443 reg &= ~0x00c0;
444 reg |= (3 - index) << 6;
445 err = regmap_write(data->regmap, LM75_REG_CONF, reg);
446 if (err < 0)
447 return err;
448 data->sample_time = data->params->sample_times[index];
449 break;
450 case pct2075:
451 err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE,
452 index + 1);
453 if (err)
454 return err;
455 data->sample_time = data->params->sample_times[index];
456 break;
457 }
458 return 0;
459}
460
461static int lm75_write_chip(struct device *dev, u32 attr, long val)
462{
463 switch (attr) {
464 case hwmon_chip_update_interval:
465 return lm75_update_interval(dev, val);
466 default:
467 return -EINVAL;
468 }
469 return 0;
470}
471
472static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
473 u32 attr, int channel, long val)
474{
475 switch (type) {
476 case hwmon_chip:
477 return lm75_write_chip(dev, attr, val);
478 case hwmon_temp:
479 return lm75_write_temp(dev, attr, val);
480 default:
481 return -EINVAL;
482 }
483 return 0;
484}
485
486static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
487 u32 attr, int channel)
488{
489 const struct lm75_data *config_data = data;
490
491 switch (type) {
492 case hwmon_chip:
493 switch (attr) {
494 case hwmon_chip_update_interval:
495 if (config_data->params->num_sample_times > 1)
496 return 0644;
497 return 0444;
498 }
499 break;
500 case hwmon_temp:
501 switch (attr) {
502 case hwmon_temp_input:
503 return 0444;
504 case hwmon_temp_max:
505 case hwmon_temp_max_hyst:
506 return 0644;
507 }
508 break;
509 default:
510 break;
511 }
512 return 0;
513}
514
515static const struct hwmon_channel_info *lm75_info[] = {
516 HWMON_CHANNEL_INFO(chip,
517 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
518 HWMON_CHANNEL_INFO(temp,
519 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
520 NULL
521};
522
523static const struct hwmon_ops lm75_hwmon_ops = {
524 .is_visible = lm75_is_visible,
525 .read = lm75_read,
526 .write = lm75_write,
527};
528
529static const struct hwmon_chip_info lm75_chip_info = {
530 .ops = &lm75_hwmon_ops,
531 .info = lm75_info,
532};
533
534static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
535{
536 return reg != LM75_REG_TEMP;
537}
538
539static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
540{
541 return reg == LM75_REG_TEMP || reg == LM75_REG_CONF;
542}
543
544static const struct regmap_config lm75_regmap_config = {
545 .reg_bits = 8,
546 .val_bits = 16,
547 .max_register = PCT2075_REG_IDLE,
548 .writeable_reg = lm75_is_writeable_reg,
549 .volatile_reg = lm75_is_volatile_reg,
550 .val_format_endian = REGMAP_ENDIAN_BIG,
551 .cache_type = REGCACHE_RBTREE,
552 .use_single_read = true,
553 .use_single_write = true,
554};
555
556static void lm75_disable_regulator(void *data)
557{
558 struct lm75_data *lm75 = data;
559
560 regulator_disable(lm75->vs);
561}
562
563static void lm75_remove(void *data)
564{
565 struct lm75_data *lm75 = data;
566 struct i2c_client *client = lm75->client;
567
568 i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
569}
570
571static const struct i2c_device_id lm75_ids[];
572
573static int lm75_probe(struct i2c_client *client)
574{
575 struct device *dev = &client->dev;
576 struct device *hwmon_dev;
577 struct lm75_data *data;
578 int status, err;
579 enum lm75_type kind;
580
581 if (client->dev.of_node)
582 kind = (enum lm75_type)of_device_get_match_data(&client->dev);
583 else
584 kind = i2c_match_id(lm75_ids, client)->driver_data;
585
586 if (!i2c_check_functionality(client->adapter,
587 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
588 return -EIO;
589
590 data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
591 if (!data)
592 return -ENOMEM;
593
594 data->client = client;
595 data->kind = kind;
596
597 data->vs = devm_regulator_get(dev, "vs");
598 if (IS_ERR(data->vs))
599 return PTR_ERR(data->vs);
600
601 data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
602 if (IS_ERR(data->regmap))
603 return PTR_ERR(data->regmap);
604
605 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
606 * Then tweak to be more precise when appropriate.
607 */
608
609 data->params = &device_params[data->kind];
610
611 /* Save default sample time and resolution*/
612 data->sample_time = data->params->default_sample_time;
613 data->resolution = data->params->default_resolution;
614
615 /* Enable the power */
616 err = regulator_enable(data->vs);
617 if (err) {
618 dev_err(dev, "failed to enable regulator: %d\n", err);
619 return err;
620 }
621
622 err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);
623 if (err)
624 return err;
625
626 /* Cache original configuration */
627 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
628 if (status < 0) {
629 dev_dbg(dev, "Can't read config? %d\n", status);
630 return status;
631 }
632 data->orig_conf = status;
633 data->current_conf = status;
634
635 err = lm75_write_config(data, data->params->set_mask,
636 data->params->clr_mask);
637 if (err)
638 return err;
639
640 err = devm_add_action_or_reset(dev, lm75_remove, data);
641 if (err)
642 return err;
643
644 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
645 data, &lm75_chip_info,
646 NULL);
647 if (IS_ERR(hwmon_dev))
648 return PTR_ERR(hwmon_dev);
649
650 dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
651
652 return 0;
653}
654
655static const struct i2c_device_id lm75_ids[] = {
656 { "adt75", adt75, },
657 { "at30ts74", at30ts74, },
658 { "ds1775", ds1775, },
659 { "ds75", ds75, },
660 { "ds7505", ds7505, },
661 { "g751", g751, },
662 { "lm75", lm75, },
663 { "lm75a", lm75a, },
664 { "lm75b", lm75b, },
665 { "max6625", max6625, },
666 { "max6626", max6626, },
667 { "max31725", max31725, },
668 { "max31726", max31725, },
669 { "mcp980x", mcp980x, },
670 { "pct2075", pct2075, },
671 { "stds75", stds75, },
672 { "stlm75", stlm75, },
673 { "tcn75", tcn75, },
674 { "tmp100", tmp100, },
675 { "tmp101", tmp101, },
676 { "tmp105", tmp105, },
677 { "tmp112", tmp112, },
678 { "tmp175", tmp175, },
679 { "tmp275", tmp275, },
680 { "tmp75", tmp75, },
681 { "tmp75b", tmp75b, },
682 { "tmp75c", tmp75c, },
683 { "tmp1075", tmp1075, },
684 { /* LIST END */ }
685};
686MODULE_DEVICE_TABLE(i2c, lm75_ids);
687
688static const struct of_device_id __maybe_unused lm75_of_match[] = {
689 {
690 .compatible = "adi,adt75",
691 .data = (void *)adt75
692 },
693 {
694 .compatible = "atmel,at30ts74",
695 .data = (void *)at30ts74
696 },
697 {
698 .compatible = "dallas,ds1775",
699 .data = (void *)ds1775
700 },
701 {
702 .compatible = "dallas,ds75",
703 .data = (void *)ds75
704 },
705 {
706 .compatible = "dallas,ds7505",
707 .data = (void *)ds7505
708 },
709 {
710 .compatible = "gmt,g751",
711 .data = (void *)g751
712 },
713 {
714 .compatible = "national,lm75",
715 .data = (void *)lm75
716 },
717 {
718 .compatible = "national,lm75a",
719 .data = (void *)lm75a
720 },
721 {
722 .compatible = "national,lm75b",
723 .data = (void *)lm75b
724 },
725 {
726 .compatible = "maxim,max6625",
727 .data = (void *)max6625
728 },
729 {
730 .compatible = "maxim,max6626",
731 .data = (void *)max6626
732 },
733 {
734 .compatible = "maxim,max31725",
735 .data = (void *)max31725
736 },
737 {
738 .compatible = "maxim,max31726",
739 .data = (void *)max31725
740 },
741 {
742 .compatible = "maxim,mcp980x",
743 .data = (void *)mcp980x
744 },
745 {
746 .compatible = "nxp,pct2075",
747 .data = (void *)pct2075
748 },
749 {
750 .compatible = "st,stds75",
751 .data = (void *)stds75
752 },
753 {
754 .compatible = "st,stlm75",
755 .data = (void *)stlm75
756 },
757 {
758 .compatible = "microchip,tcn75",
759 .data = (void *)tcn75
760 },
761 {
762 .compatible = "ti,tmp100",
763 .data = (void *)tmp100
764 },
765 {
766 .compatible = "ti,tmp101",
767 .data = (void *)tmp101
768 },
769 {
770 .compatible = "ti,tmp105",
771 .data = (void *)tmp105
772 },
773 {
774 .compatible = "ti,tmp112",
775 .data = (void *)tmp112
776 },
777 {
778 .compatible = "ti,tmp175",
779 .data = (void *)tmp175
780 },
781 {
782 .compatible = "ti,tmp275",
783 .data = (void *)tmp275
784 },
785 {
786 .compatible = "ti,tmp75",
787 .data = (void *)tmp75
788 },
789 {
790 .compatible = "ti,tmp75b",
791 .data = (void *)tmp75b
792 },
793 {
794 .compatible = "ti,tmp75c",
795 .data = (void *)tmp75c
796 },
797 {
798 .compatible = "ti,tmp1075",
799 .data = (void *)tmp1075
800 },
801 { },
802};
803MODULE_DEVICE_TABLE(of, lm75_of_match);
804
805#define LM75A_ID 0xA1
806
807/* Return 0 if detection is successful, -ENODEV otherwise */
808static int lm75_detect(struct i2c_client *new_client,
809 struct i2c_board_info *info)
810{
811 struct i2c_adapter *adapter = new_client->adapter;
812 int i;
813 int conf, hyst, os;
814 bool is_lm75a = 0;
815
816 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
817 I2C_FUNC_SMBUS_WORD_DATA))
818 return -ENODEV;
819
820 /*
821 * Now, we do the remaining detection. There is no identification-
822 * dedicated register so we have to rely on several tricks:
823 * unused bits, registers cycling over 8-address boundaries,
824 * addresses 0x04-0x07 returning the last read value.
825 * The cycling+unused addresses combination is not tested,
826 * since it would significantly slow the detection down and would
827 * hardly add any value.
828 *
829 * The National Semiconductor LM75A is different than earlier
830 * LM75s. It has an ID byte of 0xaX (where X is the chip
831 * revision, with 1 being the only revision in existence) in
832 * register 7, and unused registers return 0xff rather than the
833 * last read value.
834 *
835 * Note that this function only detects the original National
836 * Semiconductor LM75 and the LM75A. Clones from other vendors
837 * aren't detected, on purpose, because they are typically never
838 * found on PC hardware. They are found on embedded designs where
839 * they can be instantiated explicitly so detection is not needed.
840 * The absence of identification registers on all these clones
841 * would make their exhaustive detection very difficult and weak,
842 * and odds are that the driver would bind to unsupported devices.
843 */
844
845 /* Unused bits */
846 conf = i2c_smbus_read_byte_data(new_client, 1);
847 if (conf & 0xe0)
848 return -ENODEV;
849
850 /* First check for LM75A */
851 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
852 /*
853 * LM75A returns 0xff on unused registers so
854 * just to be sure we check for that too.
855 */
856 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
857 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
858 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
859 return -ENODEV;
860 is_lm75a = 1;
861 hyst = i2c_smbus_read_byte_data(new_client, 2);
862 os = i2c_smbus_read_byte_data(new_client, 3);
863 } else { /* Traditional style LM75 detection */
864 /* Unused addresses */
865 hyst = i2c_smbus_read_byte_data(new_client, 2);
866 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
867 || i2c_smbus_read_byte_data(new_client, 5) != hyst
868 || i2c_smbus_read_byte_data(new_client, 6) != hyst
869 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
870 return -ENODEV;
871 os = i2c_smbus_read_byte_data(new_client, 3);
872 if (i2c_smbus_read_byte_data(new_client, 4) != os
873 || i2c_smbus_read_byte_data(new_client, 5) != os
874 || i2c_smbus_read_byte_data(new_client, 6) != os
875 || i2c_smbus_read_byte_data(new_client, 7) != os)
876 return -ENODEV;
877 }
878 /*
879 * It is very unlikely that this is a LM75 if both
880 * hysteresis and temperature limit registers are 0.
881 */
882 if (hyst == 0 && os == 0)
883 return -ENODEV;
884
885 /* Addresses cycling */
886 for (i = 8; i <= 248; i += 40) {
887 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
888 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
889 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
890 return -ENODEV;
891 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
892 != LM75A_ID)
893 return -ENODEV;
894 }
895
896 strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
897
898 return 0;
899}
900
901#ifdef CONFIG_PM
902static int lm75_suspend(struct device *dev)
903{
904 int status;
905 struct i2c_client *client = to_i2c_client(dev);
906
907 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
908 if (status < 0) {
909 dev_dbg(&client->dev, "Can't read config? %d\n", status);
910 return status;
911 }
912 status = status | LM75_SHUTDOWN;
913 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
914 return 0;
915}
916
917static int lm75_resume(struct device *dev)
918{
919 int status;
920 struct i2c_client *client = to_i2c_client(dev);
921
922 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
923 if (status < 0) {
924 dev_dbg(&client->dev, "Can't read config? %d\n", status);
925 return status;
926 }
927 status = status & ~LM75_SHUTDOWN;
928 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
929 return 0;
930}
931
932static const struct dev_pm_ops lm75_dev_pm_ops = {
933 .suspend = lm75_suspend,
934 .resume = lm75_resume,
935};
936#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
937#else
938#define LM75_DEV_PM_OPS NULL
939#endif /* CONFIG_PM */
940
941static struct i2c_driver lm75_driver = {
942 .class = I2C_CLASS_HWMON,
943 .driver = {
944 .name = "lm75",
945 .of_match_table = of_match_ptr(lm75_of_match),
946 .pm = LM75_DEV_PM_OPS,
947 },
948 .probe_new = lm75_probe,
949 .id_table = lm75_ids,
950 .detect = lm75_detect,
951 .address_list = normal_i2c,
952};
953
954module_i2c_driver(lm75_driver);
955
956MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
957MODULE_DESCRIPTION("LM75 driver");
958MODULE_LICENSE("GPL");
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/of.h>
30#include <linux/regmap.h>
31#include "lm75.h"
32
33
34/*
35 * This driver handles the LM75 and compatible digital temperature sensors.
36 */
37
38enum lm75_type { /* keep sorted in alphabetical order */
39 adt75,
40 ds1775,
41 ds75,
42 ds7505,
43 g751,
44 lm75,
45 lm75a,
46 lm75b,
47 max6625,
48 max6626,
49 mcp980x,
50 stds75,
51 tcn75,
52 tmp100,
53 tmp101,
54 tmp105,
55 tmp112,
56 tmp175,
57 tmp275,
58 tmp75,
59 tmp75c,
60};
61
62/* Addresses scanned */
63static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
64 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
65
66
67/* The LM75 registers */
68#define LM75_REG_TEMP 0x00
69#define LM75_REG_CONF 0x01
70#define LM75_REG_HYST 0x02
71#define LM75_REG_MAX 0x03
72
73/* Each client has this additional data */
74struct lm75_data {
75 struct i2c_client *client;
76 struct regmap *regmap;
77 u8 orig_conf;
78 u8 resolution; /* In bits, between 9 and 12 */
79 u8 resolution_limits;
80 unsigned int sample_time; /* In ms */
81};
82
83/*-----------------------------------------------------------------------*/
84
85static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
86{
87 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
88}
89
90static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
91 u32 attr, int channel, long *val)
92{
93 struct lm75_data *data = dev_get_drvdata(dev);
94 unsigned int regval;
95 int err, reg;
96
97 switch (type) {
98 case hwmon_chip:
99 switch (attr) {
100 case hwmon_chip_update_interval:
101 *val = data->sample_time;
102 break;;
103 default:
104 return -EINVAL;
105 }
106 break;
107 case hwmon_temp:
108 switch (attr) {
109 case hwmon_temp_input:
110 reg = LM75_REG_TEMP;
111 break;
112 case hwmon_temp_max:
113 reg = LM75_REG_MAX;
114 break;
115 case hwmon_temp_max_hyst:
116 reg = LM75_REG_HYST;
117 break;
118 default:
119 return -EINVAL;
120 }
121 err = regmap_read(data->regmap, reg, ®val);
122 if (err < 0)
123 return err;
124
125 *val = lm75_reg_to_mc(regval, data->resolution);
126 break;
127 default:
128 return -EINVAL;
129 }
130 return 0;
131}
132
133static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
134 u32 attr, int channel, long temp)
135{
136 struct lm75_data *data = dev_get_drvdata(dev);
137 u8 resolution;
138 int reg;
139
140 if (type != hwmon_temp)
141 return -EINVAL;
142
143 switch (attr) {
144 case hwmon_temp_max:
145 reg = LM75_REG_MAX;
146 break;
147 case hwmon_temp_max_hyst:
148 reg = LM75_REG_HYST;
149 break;
150 default:
151 return -EINVAL;
152 }
153
154 /*
155 * Resolution of limit registers is assumed to be the same as the
156 * temperature input register resolution unless given explicitly.
157 */
158 if (data->resolution_limits)
159 resolution = data->resolution_limits;
160 else
161 resolution = data->resolution;
162
163 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
164 temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
165 1000) << (16 - resolution);
166
167 return regmap_write(data->regmap, reg, temp);
168}
169
170static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
171 u32 attr, int channel)
172{
173 switch (type) {
174 case hwmon_chip:
175 switch (attr) {
176 case hwmon_chip_update_interval:
177 return S_IRUGO;
178 }
179 break;
180 case hwmon_temp:
181 switch (attr) {
182 case hwmon_temp_input:
183 return S_IRUGO;
184 case hwmon_temp_max:
185 case hwmon_temp_max_hyst:
186 return S_IRUGO | S_IWUSR;
187 }
188 break;
189 default:
190 break;
191 }
192 return 0;
193}
194
195/*-----------------------------------------------------------------------*/
196
197/* device probe and removal */
198
199/* chip configuration */
200
201static const u32 lm75_chip_config[] = {
202 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
203 0
204};
205
206static const struct hwmon_channel_info lm75_chip = {
207 .type = hwmon_chip,
208 .config = lm75_chip_config,
209};
210
211static const u32 lm75_temp_config[] = {
212 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST,
213 0
214};
215
216static const struct hwmon_channel_info lm75_temp = {
217 .type = hwmon_temp,
218 .config = lm75_temp_config,
219};
220
221static const struct hwmon_channel_info *lm75_info[] = {
222 &lm75_chip,
223 &lm75_temp,
224 NULL
225};
226
227static const struct hwmon_ops lm75_hwmon_ops = {
228 .is_visible = lm75_is_visible,
229 .read = lm75_read,
230 .write = lm75_write,
231};
232
233static const struct hwmon_chip_info lm75_chip_info = {
234 .ops = &lm75_hwmon_ops,
235 .info = lm75_info,
236};
237
238static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
239{
240 return reg != LM75_REG_TEMP;
241}
242
243static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
244{
245 return reg == LM75_REG_TEMP;
246}
247
248static const struct regmap_config lm75_regmap_config = {
249 .reg_bits = 8,
250 .val_bits = 16,
251 .max_register = LM75_REG_MAX,
252 .writeable_reg = lm75_is_writeable_reg,
253 .volatile_reg = lm75_is_volatile_reg,
254 .val_format_endian = REGMAP_ENDIAN_BIG,
255 .cache_type = REGCACHE_RBTREE,
256 .use_single_rw = true,
257};
258
259static void lm75_remove(void *data)
260{
261 struct lm75_data *lm75 = data;
262 struct i2c_client *client = lm75->client;
263
264 i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
265}
266
267static int
268lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
269{
270 struct device *dev = &client->dev;
271 struct device *hwmon_dev;
272 struct lm75_data *data;
273 int status, err;
274 u8 set_mask, clr_mask;
275 int new;
276 enum lm75_type kind = id->driver_data;
277
278 if (!i2c_check_functionality(client->adapter,
279 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
280 return -EIO;
281
282 data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
283 if (!data)
284 return -ENOMEM;
285
286 data->client = client;
287
288 data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
289 if (IS_ERR(data->regmap))
290 return PTR_ERR(data->regmap);
291
292 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
293 * Then tweak to be more precise when appropriate.
294 */
295 set_mask = 0;
296 clr_mask = LM75_SHUTDOWN; /* continuous conversions */
297
298 switch (kind) {
299 case adt75:
300 clr_mask |= 1 << 5; /* not one-shot mode */
301 data->resolution = 12;
302 data->sample_time = MSEC_PER_SEC / 8;
303 break;
304 case ds1775:
305 case ds75:
306 case stds75:
307 clr_mask |= 3 << 5;
308 set_mask |= 2 << 5; /* 11-bit mode */
309 data->resolution = 11;
310 data->sample_time = MSEC_PER_SEC;
311 break;
312 case ds7505:
313 set_mask |= 3 << 5; /* 12-bit mode */
314 data->resolution = 12;
315 data->sample_time = MSEC_PER_SEC / 4;
316 break;
317 case g751:
318 case lm75:
319 case lm75a:
320 data->resolution = 9;
321 data->sample_time = MSEC_PER_SEC / 2;
322 break;
323 case lm75b:
324 data->resolution = 11;
325 data->sample_time = MSEC_PER_SEC / 4;
326 break;
327 case max6625:
328 data->resolution = 9;
329 data->sample_time = MSEC_PER_SEC / 4;
330 break;
331 case max6626:
332 data->resolution = 12;
333 data->resolution_limits = 9;
334 data->sample_time = MSEC_PER_SEC / 4;
335 break;
336 case tcn75:
337 data->resolution = 9;
338 data->sample_time = MSEC_PER_SEC / 8;
339 break;
340 case mcp980x:
341 data->resolution_limits = 9;
342 /* fall through */
343 case tmp100:
344 case tmp101:
345 set_mask |= 3 << 5; /* 12-bit mode */
346 data->resolution = 12;
347 data->sample_time = MSEC_PER_SEC;
348 clr_mask |= 1 << 7; /* not one-shot mode */
349 break;
350 case tmp112:
351 set_mask |= 3 << 5; /* 12-bit mode */
352 clr_mask |= 1 << 7; /* not one-shot mode */
353 data->resolution = 12;
354 data->sample_time = MSEC_PER_SEC / 4;
355 break;
356 case tmp105:
357 case tmp175:
358 case tmp275:
359 case tmp75:
360 set_mask |= 3 << 5; /* 12-bit mode */
361 clr_mask |= 1 << 7; /* not one-shot mode */
362 data->resolution = 12;
363 data->sample_time = MSEC_PER_SEC / 2;
364 break;
365 case tmp75c:
366 clr_mask |= 1 << 5; /* not one-shot mode */
367 data->resolution = 12;
368 data->sample_time = MSEC_PER_SEC / 4;
369 break;
370 }
371
372 /* configure as specified */
373 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
374 if (status < 0) {
375 dev_dbg(dev, "Can't read config? %d\n", status);
376 return status;
377 }
378 data->orig_conf = status;
379 new = status & ~clr_mask;
380 new |= set_mask;
381 if (status != new)
382 i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
383
384 err = devm_add_action_or_reset(dev, lm75_remove, data);
385 if (err)
386 return err;
387
388 dev_dbg(dev, "Config %02x\n", new);
389
390 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
391 data, &lm75_chip_info,
392 NULL);
393 if (IS_ERR(hwmon_dev))
394 return PTR_ERR(hwmon_dev);
395
396 dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
397
398 return 0;
399}
400
401static const struct i2c_device_id lm75_ids[] = {
402 { "adt75", adt75, },
403 { "ds1775", ds1775, },
404 { "ds75", ds75, },
405 { "ds7505", ds7505, },
406 { "g751", g751, },
407 { "lm75", lm75, },
408 { "lm75a", lm75a, },
409 { "lm75b", lm75b, },
410 { "max6625", max6625, },
411 { "max6626", max6626, },
412 { "mcp980x", mcp980x, },
413 { "stds75", stds75, },
414 { "tcn75", tcn75, },
415 { "tmp100", tmp100, },
416 { "tmp101", tmp101, },
417 { "tmp105", tmp105, },
418 { "tmp112", tmp112, },
419 { "tmp175", tmp175, },
420 { "tmp275", tmp275, },
421 { "tmp75", tmp75, },
422 { "tmp75c", tmp75c, },
423 { /* LIST END */ }
424};
425MODULE_DEVICE_TABLE(i2c, lm75_ids);
426
427#define LM75A_ID 0xA1
428
429/* Return 0 if detection is successful, -ENODEV otherwise */
430static int lm75_detect(struct i2c_client *new_client,
431 struct i2c_board_info *info)
432{
433 struct i2c_adapter *adapter = new_client->adapter;
434 int i;
435 int conf, hyst, os;
436 bool is_lm75a = 0;
437
438 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
439 I2C_FUNC_SMBUS_WORD_DATA))
440 return -ENODEV;
441
442 /*
443 * Now, we do the remaining detection. There is no identification-
444 * dedicated register so we have to rely on several tricks:
445 * unused bits, registers cycling over 8-address boundaries,
446 * addresses 0x04-0x07 returning the last read value.
447 * The cycling+unused addresses combination is not tested,
448 * since it would significantly slow the detection down and would
449 * hardly add any value.
450 *
451 * The National Semiconductor LM75A is different than earlier
452 * LM75s. It has an ID byte of 0xaX (where X is the chip
453 * revision, with 1 being the only revision in existence) in
454 * register 7, and unused registers return 0xff rather than the
455 * last read value.
456 *
457 * Note that this function only detects the original National
458 * Semiconductor LM75 and the LM75A. Clones from other vendors
459 * aren't detected, on purpose, because they are typically never
460 * found on PC hardware. They are found on embedded designs where
461 * they can be instantiated explicitly so detection is not needed.
462 * The absence of identification registers on all these clones
463 * would make their exhaustive detection very difficult and weak,
464 * and odds are that the driver would bind to unsupported devices.
465 */
466
467 /* Unused bits */
468 conf = i2c_smbus_read_byte_data(new_client, 1);
469 if (conf & 0xe0)
470 return -ENODEV;
471
472 /* First check for LM75A */
473 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
474 /* LM75A returns 0xff on unused registers so
475 just to be sure we check for that too. */
476 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
477 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
478 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
479 return -ENODEV;
480 is_lm75a = 1;
481 hyst = i2c_smbus_read_byte_data(new_client, 2);
482 os = i2c_smbus_read_byte_data(new_client, 3);
483 } else { /* Traditional style LM75 detection */
484 /* Unused addresses */
485 hyst = i2c_smbus_read_byte_data(new_client, 2);
486 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
487 || i2c_smbus_read_byte_data(new_client, 5) != hyst
488 || i2c_smbus_read_byte_data(new_client, 6) != hyst
489 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
490 return -ENODEV;
491 os = i2c_smbus_read_byte_data(new_client, 3);
492 if (i2c_smbus_read_byte_data(new_client, 4) != os
493 || i2c_smbus_read_byte_data(new_client, 5) != os
494 || i2c_smbus_read_byte_data(new_client, 6) != os
495 || i2c_smbus_read_byte_data(new_client, 7) != os)
496 return -ENODEV;
497 }
498 /*
499 * It is very unlikely that this is a LM75 if both
500 * hysteresis and temperature limit registers are 0.
501 */
502 if (hyst == 0 && os == 0)
503 return -ENODEV;
504
505 /* Addresses cycling */
506 for (i = 8; i <= 248; i += 40) {
507 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
508 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
509 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
510 return -ENODEV;
511 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
512 != LM75A_ID)
513 return -ENODEV;
514 }
515
516 strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
517
518 return 0;
519}
520
521#ifdef CONFIG_PM
522static int lm75_suspend(struct device *dev)
523{
524 int status;
525 struct i2c_client *client = to_i2c_client(dev);
526 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
527 if (status < 0) {
528 dev_dbg(&client->dev, "Can't read config? %d\n", status);
529 return status;
530 }
531 status = status | LM75_SHUTDOWN;
532 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
533 return 0;
534}
535
536static int lm75_resume(struct device *dev)
537{
538 int status;
539 struct i2c_client *client = to_i2c_client(dev);
540 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
541 if (status < 0) {
542 dev_dbg(&client->dev, "Can't read config? %d\n", status);
543 return status;
544 }
545 status = status & ~LM75_SHUTDOWN;
546 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
547 return 0;
548}
549
550static const struct dev_pm_ops lm75_dev_pm_ops = {
551 .suspend = lm75_suspend,
552 .resume = lm75_resume,
553};
554#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
555#else
556#define LM75_DEV_PM_OPS NULL
557#endif /* CONFIG_PM */
558
559static struct i2c_driver lm75_driver = {
560 .class = I2C_CLASS_HWMON,
561 .driver = {
562 .name = "lm75",
563 .pm = LM75_DEV_PM_OPS,
564 },
565 .probe = lm75_probe,
566 .id_table = lm75_ids,
567 .detect = lm75_detect,
568 .address_list = normal_i2c,
569};
570
571module_i2c_driver(lm75_driver);
572
573MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
574MODULE_DESCRIPTION("LM75 driver");
575MODULE_LICENSE("GPL");