Loading...
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/interrupt.h>
11#include <linux/slab.h>
12#include <linux/jiffies.h>
13#include <linux/i2c.h>
14#include <linux/hwmon.h>
15#include <linux/err.h>
16#include <linux/of.h>
17#include <linux/regmap.h>
18#include <linux/util_macros.h>
19#include <linux/regulator/consumer.h>
20#include "lm75.h"
21
22/*
23 * This driver handles the LM75 and compatible digital temperature sensors.
24 */
25
26enum lm75_type { /* keep sorted in alphabetical order */
27 adt75,
28 as6200,
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 * @config_reg_16bits: Configure register size is 2 bytes.
60 * @set_mask: Bits to set in configuration register when configuring
61 * the chip.
62 * @clr_mask: Bits to clear in configuration register when configuring
63 * the chip.
64 * @default_resolution: Default number of bits to represent the temperature
65 * value.
66 * @resolution_limits: Limit register resolution. Optional. Should be set if
67 * the resolution of limit registers does not match the
68 * resolution of the temperature register.
69 * @resolutions: List of resolutions associated with sample times.
70 * Optional. Should be set if num_sample_times is larger
71 * than 1, and if the resolution changes with sample times.
72 * If set, number of entries must match num_sample_times.
73 * @default_sample_time:Sample time to be set by default.
74 * @num_sample_times: Number of possible sample times to be set. Optional.
75 * Should be set if the number of sample times is larger
76 * than one.
77 * @sample_times: All the possible sample times to be set. Mandatory if
78 * num_sample_times is larger than 1. If set, number of
79 * entries must match num_sample_times.
80 * @alarm: Alarm bit is supported.
81 */
82
83struct lm75_params {
84 bool config_reg_16bits;
85 u16 set_mask;
86 u16 clr_mask;
87 u8 default_resolution;
88 u8 resolution_limits;
89 const u8 *resolutions;
90 unsigned int default_sample_time;
91 u8 num_sample_times;
92 const unsigned int *sample_times;
93 bool alarm;
94};
95
96/* Addresses scanned */
97static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
98 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
99
100/* The LM75 registers */
101#define LM75_REG_TEMP 0x00
102#define LM75_REG_CONF 0x01
103#define LM75_REG_HYST 0x02
104#define LM75_REG_MAX 0x03
105#define PCT2075_REG_IDLE 0x04
106
107/* Each client has this additional data */
108struct lm75_data {
109 struct i2c_client *client;
110 struct regmap *regmap;
111 struct regulator *vs;
112 u16 orig_conf;
113 u16 current_conf;
114 u8 resolution; /* In bits, 9 to 16 */
115 unsigned int sample_time; /* In ms */
116 enum lm75_type kind;
117 const struct lm75_params *params;
118};
119
120/*-----------------------------------------------------------------------*/
121
122static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };
123
124#define LM75_SAMPLE_CLEAR_MASK (3 << 5)
125
126/* The structure below stores the configuration values of the supported devices.
127 * In case of being supported multiple configurations, the default one must
128 * always be the first element of the array
129 */
130static const struct lm75_params device_params[] = {
131 [adt75] = {
132 .clr_mask = 1 << 5, /* not one-shot mode */
133 .default_resolution = 12,
134 .default_sample_time = MSEC_PER_SEC / 10,
135 },
136 [as6200] = {
137 .config_reg_16bits = true,
138 .set_mask = 0x94C0, /* 8 sample/s, 4 CF, positive polarity */
139 .default_resolution = 12,
140 .default_sample_time = 125,
141 .num_sample_times = 4,
142 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
143 .alarm = true,
144 },
145 [at30ts74] = {
146 .set_mask = 3 << 5, /* 12-bit mode*/
147 .default_resolution = 12,
148 .default_sample_time = 200,
149 .num_sample_times = 4,
150 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
151 .resolutions = (u8 []) {9, 10, 11, 12 },
152 },
153 [ds1775] = {
154 .clr_mask = 3 << 5,
155 .set_mask = 2 << 5, /* 11-bit mode */
156 .default_resolution = 11,
157 .default_sample_time = 500,
158 .num_sample_times = 4,
159 .sample_times = (unsigned int []){ 125, 250, 500, 1000 },
160 .resolutions = (u8 []) {9, 10, 11, 12 },
161 },
162 [ds75] = {
163 .clr_mask = 3 << 5,
164 .set_mask = 2 << 5, /* 11-bit mode */
165 .default_resolution = 11,
166 .default_sample_time = 600,
167 .num_sample_times = 4,
168 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
169 .resolutions = (u8 []) {9, 10, 11, 12 },
170 },
171 [stds75] = {
172 .clr_mask = 3 << 5,
173 .set_mask = 2 << 5, /* 11-bit mode */
174 .default_resolution = 11,
175 .default_sample_time = 600,
176 .num_sample_times = 4,
177 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
178 .resolutions = (u8 []) {9, 10, 11, 12 },
179 },
180 [stlm75] = {
181 .default_resolution = 9,
182 .default_sample_time = MSEC_PER_SEC / 6,
183 },
184 [ds7505] = {
185 .set_mask = 3 << 5, /* 12-bit mode*/
186 .default_resolution = 12,
187 .default_sample_time = 200,
188 .num_sample_times = 4,
189 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
190 .resolutions = (u8 []) {9, 10, 11, 12 },
191 },
192 [g751] = {
193 .default_resolution = 9,
194 .default_sample_time = MSEC_PER_SEC / 10,
195 },
196 [lm75] = {
197 .default_resolution = 9,
198 .default_sample_time = MSEC_PER_SEC / 10,
199 },
200 [lm75a] = {
201 .default_resolution = 9,
202 .default_sample_time = MSEC_PER_SEC / 10,
203 },
204 [lm75b] = {
205 .default_resolution = 11,
206 .default_sample_time = MSEC_PER_SEC / 10,
207 },
208 [max6625] = {
209 .default_resolution = 9,
210 .default_sample_time = MSEC_PER_SEC / 7,
211 },
212 [max6626] = {
213 .default_resolution = 12,
214 .default_sample_time = MSEC_PER_SEC / 7,
215 .resolution_limits = 9,
216 },
217 [max31725] = {
218 .default_resolution = 16,
219 .default_sample_time = MSEC_PER_SEC / 20,
220 },
221 [tcn75] = {
222 .default_resolution = 9,
223 .default_sample_time = MSEC_PER_SEC / 18,
224 },
225 [pct2075] = {
226 .default_resolution = 11,
227 .default_sample_time = MSEC_PER_SEC / 10,
228 .num_sample_times = 31,
229 .sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600,
230 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700,
231 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700,
232 2800, 2900, 3000, 3100 },
233 },
234 [mcp980x] = {
235 .set_mask = 3 << 5, /* 12-bit mode */
236 .clr_mask = 1 << 7, /* not one-shot mode */
237 .default_resolution = 12,
238 .resolution_limits = 9,
239 .default_sample_time = 240,
240 .num_sample_times = 4,
241 .sample_times = (unsigned int []){ 30, 60, 120, 240 },
242 .resolutions = (u8 []) {9, 10, 11, 12 },
243 },
244 [tmp100] = {
245 .set_mask = 3 << 5, /* 12-bit mode */
246 .clr_mask = 1 << 7, /* not one-shot mode */
247 .default_resolution = 12,
248 .default_sample_time = 320,
249 .num_sample_times = 4,
250 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
251 .resolutions = (u8 []) {9, 10, 11, 12 },
252 },
253 [tmp101] = {
254 .set_mask = 3 << 5, /* 12-bit mode */
255 .clr_mask = 1 << 7, /* not one-shot mode */
256 .default_resolution = 12,
257 .default_sample_time = 320,
258 .num_sample_times = 4,
259 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
260 .resolutions = (u8 []) {9, 10, 11, 12 },
261 },
262 [tmp105] = {
263 .set_mask = 3 << 5, /* 12-bit mode */
264 .clr_mask = 1 << 7, /* not one-shot mode*/
265 .default_resolution = 12,
266 .default_sample_time = 220,
267 .num_sample_times = 4,
268 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
269 .resolutions = (u8 []) {9, 10, 11, 12 },
270 },
271 [tmp112] = {
272 .config_reg_16bits = true,
273 .set_mask = 0x60C0, /* 12-bit mode, 8 samples / second */
274 .clr_mask = 1 << 15, /* no one-shot mode*/
275 .default_resolution = 12,
276 .default_sample_time = 125,
277 .num_sample_times = 4,
278 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
279 },
280 [tmp175] = {
281 .set_mask = 3 << 5, /* 12-bit mode */
282 .clr_mask = 1 << 7, /* not one-shot mode*/
283 .default_resolution = 12,
284 .default_sample_time = 220,
285 .num_sample_times = 4,
286 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
287 .resolutions = (u8 []) {9, 10, 11, 12 },
288 },
289 [tmp275] = {
290 .set_mask = 3 << 5, /* 12-bit mode */
291 .clr_mask = 1 << 7, /* not one-shot mode*/
292 .default_resolution = 12,
293 .default_sample_time = 220,
294 .num_sample_times = 4,
295 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
296 .resolutions = (u8 []) {9, 10, 11, 12 },
297 },
298 [tmp75] = {
299 .set_mask = 3 << 5, /* 12-bit mode */
300 .clr_mask = 1 << 7, /* not one-shot mode*/
301 .default_resolution = 12,
302 .default_sample_time = 220,
303 .num_sample_times = 4,
304 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
305 .resolutions = (u8 []) {9, 10, 11, 12 },
306 },
307 [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */
308 .clr_mask = 1 << 7 | 3 << 5,
309 .default_resolution = 12,
310 .default_sample_time = MSEC_PER_SEC / 37,
311 .sample_times = (unsigned int []){ MSEC_PER_SEC / 37,
312 MSEC_PER_SEC / 18,
313 MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 },
314 .num_sample_times = 4,
315 },
316 [tmp75c] = {
317 .clr_mask = 1 << 5, /*not one-shot mode*/
318 .default_resolution = 12,
319 .default_sample_time = MSEC_PER_SEC / 12,
320 },
321 [tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */
322 .clr_mask = 1 << 5 | 1 << 6 | 1 << 7,
323 .default_resolution = 12,
324 .default_sample_time = 28,
325 .num_sample_times = 4,
326 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
327 }
328};
329
330static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
331{
332 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
333}
334
335static int lm75_write_config(struct lm75_data *data, u16 set_mask,
336 u16 clr_mask)
337{
338 unsigned int value;
339
340 clr_mask |= LM75_SHUTDOWN << (8 * data->params->config_reg_16bits);
341 value = data->current_conf & ~clr_mask;
342 value |= set_mask;
343
344 if (data->current_conf != value) {
345 s32 err;
346 if (data->params->config_reg_16bits)
347 err = regmap_write(data->regmap, LM75_REG_CONF, value);
348 else
349 err = i2c_smbus_write_byte_data(data->client,
350 LM75_REG_CONF,
351 value);
352 if (err)
353 return err;
354 data->current_conf = value;
355 }
356 return 0;
357}
358
359static int lm75_read_config(struct lm75_data *data)
360{
361 int ret;
362 unsigned int status;
363
364 if (data->params->config_reg_16bits) {
365 ret = regmap_read(data->regmap, LM75_REG_CONF, &status);
366 return ret ? ret : status;
367 }
368
369 return i2c_smbus_read_byte_data(data->client, LM75_REG_CONF);
370}
371
372static irqreturn_t lm75_alarm_handler(int irq, void *private)
373{
374 struct device *hwmon_dev = private;
375
376 hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_alarm, 0);
377 return IRQ_HANDLED;
378}
379
380static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
381 u32 attr, int channel, long *val)
382{
383 struct lm75_data *data = dev_get_drvdata(dev);
384 unsigned int regval;
385 int err, reg;
386
387 switch (type) {
388 case hwmon_chip:
389 switch (attr) {
390 case hwmon_chip_update_interval:
391 *val = data->sample_time;
392 break;
393 default:
394 return -EINVAL;
395 }
396 break;
397 case hwmon_temp:
398 switch (attr) {
399 case hwmon_temp_input:
400 reg = LM75_REG_TEMP;
401 break;
402 case hwmon_temp_max:
403 reg = LM75_REG_MAX;
404 break;
405 case hwmon_temp_max_hyst:
406 reg = LM75_REG_HYST;
407 break;
408 case hwmon_temp_alarm:
409 reg = LM75_REG_CONF;
410 break;
411 default:
412 return -EINVAL;
413 }
414 err = regmap_read(data->regmap, reg, ®val);
415 if (err < 0)
416 return err;
417
418 if (attr == hwmon_temp_alarm) {
419 switch (data->kind) {
420 case as6200:
421 *val = (regval >> 5) & 0x1;
422 break;
423 default:
424 return -EINVAL;
425 }
426 } else {
427 *val = lm75_reg_to_mc(regval, data->resolution);
428 }
429 break;
430 default:
431 return -EINVAL;
432 }
433 return 0;
434}
435
436static int lm75_write_temp(struct device *dev, u32 attr, long temp)
437{
438 struct lm75_data *data = dev_get_drvdata(dev);
439 u8 resolution;
440 int reg;
441
442 switch (attr) {
443 case hwmon_temp_max:
444 reg = LM75_REG_MAX;
445 break;
446 case hwmon_temp_max_hyst:
447 reg = LM75_REG_HYST;
448 break;
449 default:
450 return -EINVAL;
451 }
452
453 /*
454 * Resolution of limit registers is assumed to be the same as the
455 * temperature input register resolution unless given explicitly.
456 */
457 if (data->params->resolution_limits)
458 resolution = data->params->resolution_limits;
459 else
460 resolution = data->resolution;
461
462 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
463 temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
464 1000) << (16 - resolution);
465
466 return regmap_write(data->regmap, reg, (u16)temp);
467}
468
469static int lm75_update_interval(struct device *dev, long val)
470{
471 struct lm75_data *data = dev_get_drvdata(dev);
472 unsigned int reg;
473 u8 index;
474 s32 err;
475
476 index = find_closest(val, data->params->sample_times,
477 (int)data->params->num_sample_times);
478
479 switch (data->kind) {
480 default:
481 err = lm75_write_config(data, lm75_sample_set_masks[index],
482 LM75_SAMPLE_CLEAR_MASK);
483 if (err)
484 return err;
485
486 data->sample_time = data->params->sample_times[index];
487 if (data->params->resolutions)
488 data->resolution = data->params->resolutions[index];
489 break;
490 case tmp112:
491 case as6200:
492 err = regmap_read(data->regmap, LM75_REG_CONF, ®);
493 if (err < 0)
494 return err;
495 reg &= ~0x00c0;
496 reg |= (3 - index) << 6;
497 err = regmap_write(data->regmap, LM75_REG_CONF, reg);
498 if (err < 0)
499 return err;
500 data->sample_time = data->params->sample_times[index];
501 break;
502 case pct2075:
503 err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE,
504 index + 1);
505 if (err)
506 return err;
507 data->sample_time = data->params->sample_times[index];
508 break;
509 }
510 return 0;
511}
512
513static int lm75_write_chip(struct device *dev, u32 attr, long val)
514{
515 switch (attr) {
516 case hwmon_chip_update_interval:
517 return lm75_update_interval(dev, val);
518 default:
519 return -EINVAL;
520 }
521 return 0;
522}
523
524static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
525 u32 attr, int channel, long val)
526{
527 switch (type) {
528 case hwmon_chip:
529 return lm75_write_chip(dev, attr, val);
530 case hwmon_temp:
531 return lm75_write_temp(dev, attr, val);
532 default:
533 return -EINVAL;
534 }
535 return 0;
536}
537
538static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
539 u32 attr, int channel)
540{
541 const struct lm75_data *config_data = data;
542
543 switch (type) {
544 case hwmon_chip:
545 switch (attr) {
546 case hwmon_chip_update_interval:
547 if (config_data->params->num_sample_times > 1)
548 return 0644;
549 return 0444;
550 }
551 break;
552 case hwmon_temp:
553 switch (attr) {
554 case hwmon_temp_input:
555 return 0444;
556 case hwmon_temp_max:
557 case hwmon_temp_max_hyst:
558 return 0644;
559 case hwmon_temp_alarm:
560 if (config_data->params->alarm)
561 return 0444;
562 break;
563 }
564 break;
565 default:
566 break;
567 }
568 return 0;
569}
570
571static const struct hwmon_channel_info * const lm75_info[] = {
572 HWMON_CHANNEL_INFO(chip,
573 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
574 HWMON_CHANNEL_INFO(temp,
575 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
576 HWMON_T_ALARM),
577 NULL
578};
579
580static const struct hwmon_ops lm75_hwmon_ops = {
581 .is_visible = lm75_is_visible,
582 .read = lm75_read,
583 .write = lm75_write,
584};
585
586static const struct hwmon_chip_info lm75_chip_info = {
587 .ops = &lm75_hwmon_ops,
588 .info = lm75_info,
589};
590
591static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
592{
593 return reg != LM75_REG_TEMP;
594}
595
596static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
597{
598 return reg == LM75_REG_TEMP || reg == LM75_REG_CONF;
599}
600
601static const struct regmap_config lm75_regmap_config = {
602 .reg_bits = 8,
603 .val_bits = 16,
604 .max_register = PCT2075_REG_IDLE,
605 .writeable_reg = lm75_is_writeable_reg,
606 .volatile_reg = lm75_is_volatile_reg,
607 .val_format_endian = REGMAP_ENDIAN_BIG,
608 .cache_type = REGCACHE_MAPLE,
609 .use_single_read = true,
610 .use_single_write = true,
611};
612
613static void lm75_disable_regulator(void *data)
614{
615 struct lm75_data *lm75 = data;
616
617 regulator_disable(lm75->vs);
618}
619
620static void lm75_remove(void *data)
621{
622 struct lm75_data *lm75 = data;
623 struct i2c_client *client = lm75->client;
624
625 i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
626}
627
628static const struct i2c_device_id lm75_ids[];
629
630static int lm75_probe(struct i2c_client *client)
631{
632 struct device *dev = &client->dev;
633 struct device *hwmon_dev;
634 struct lm75_data *data;
635 int status, err;
636 enum lm75_type kind;
637
638 if (client->dev.of_node)
639 kind = (uintptr_t)of_device_get_match_data(&client->dev);
640 else
641 kind = i2c_match_id(lm75_ids, client)->driver_data;
642
643 if (!i2c_check_functionality(client->adapter,
644 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
645 return -EIO;
646
647 data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
648 if (!data)
649 return -ENOMEM;
650
651 data->client = client;
652 data->kind = kind;
653
654 data->vs = devm_regulator_get(dev, "vs");
655 if (IS_ERR(data->vs))
656 return PTR_ERR(data->vs);
657
658 data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
659 if (IS_ERR(data->regmap))
660 return PTR_ERR(data->regmap);
661
662 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
663 * Then tweak to be more precise when appropriate.
664 */
665
666 data->params = &device_params[data->kind];
667
668 /* Save default sample time and resolution*/
669 data->sample_time = data->params->default_sample_time;
670 data->resolution = data->params->default_resolution;
671
672 /* Enable the power */
673 err = regulator_enable(data->vs);
674 if (err) {
675 dev_err(dev, "failed to enable regulator: %d\n", err);
676 return err;
677 }
678
679 err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);
680 if (err)
681 return err;
682
683 /* Cache original configuration */
684 status = lm75_read_config(data);
685 if (status < 0) {
686 dev_dbg(dev, "Can't read config? %d\n", status);
687 return status;
688 }
689 data->orig_conf = status;
690 data->current_conf = status;
691
692 err = lm75_write_config(data, data->params->set_mask,
693 data->params->clr_mask);
694 if (err)
695 return err;
696
697 err = devm_add_action_or_reset(dev, lm75_remove, data);
698 if (err)
699 return err;
700
701 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
702 data, &lm75_chip_info,
703 NULL);
704 if (IS_ERR(hwmon_dev))
705 return PTR_ERR(hwmon_dev);
706
707 if (client->irq) {
708 if (data->params->alarm) {
709 err = devm_request_threaded_irq(dev,
710 client->irq,
711 NULL,
712 &lm75_alarm_handler,
713 IRQF_ONESHOT,
714 client->name,
715 hwmon_dev);
716 if (err)
717 return err;
718 } else {
719 /* alarm is only supported for chips with alarm bit */
720 dev_err(dev, "alarm interrupt is not supported\n");
721 }
722 }
723
724 dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
725
726 return 0;
727}
728
729static const struct i2c_device_id lm75_ids[] = {
730 { "adt75", adt75, },
731 { "as6200", as6200, },
732 { "at30ts74", at30ts74, },
733 { "ds1775", ds1775, },
734 { "ds75", ds75, },
735 { "ds7505", ds7505, },
736 { "g751", g751, },
737 { "lm75", lm75, },
738 { "lm75a", lm75a, },
739 { "lm75b", lm75b, },
740 { "max6625", max6625, },
741 { "max6626", max6626, },
742 { "max31725", max31725, },
743 { "max31726", max31725, },
744 { "mcp980x", mcp980x, },
745 { "pct2075", pct2075, },
746 { "stds75", stds75, },
747 { "stlm75", stlm75, },
748 { "tcn75", tcn75, },
749 { "tmp100", tmp100, },
750 { "tmp101", tmp101, },
751 { "tmp105", tmp105, },
752 { "tmp112", tmp112, },
753 { "tmp175", tmp175, },
754 { "tmp275", tmp275, },
755 { "tmp75", tmp75, },
756 { "tmp75b", tmp75b, },
757 { "tmp75c", tmp75c, },
758 { "tmp1075", tmp1075, },
759 { /* LIST END */ }
760};
761MODULE_DEVICE_TABLE(i2c, lm75_ids);
762
763static const struct of_device_id __maybe_unused lm75_of_match[] = {
764 {
765 .compatible = "adi,adt75",
766 .data = (void *)adt75
767 },
768 {
769 .compatible = "ams,as6200",
770 .data = (void *)as6200
771 },
772 {
773 .compatible = "atmel,at30ts74",
774 .data = (void *)at30ts74
775 },
776 {
777 .compatible = "dallas,ds1775",
778 .data = (void *)ds1775
779 },
780 {
781 .compatible = "dallas,ds75",
782 .data = (void *)ds75
783 },
784 {
785 .compatible = "dallas,ds7505",
786 .data = (void *)ds7505
787 },
788 {
789 .compatible = "gmt,g751",
790 .data = (void *)g751
791 },
792 {
793 .compatible = "national,lm75",
794 .data = (void *)lm75
795 },
796 {
797 .compatible = "national,lm75a",
798 .data = (void *)lm75a
799 },
800 {
801 .compatible = "national,lm75b",
802 .data = (void *)lm75b
803 },
804 {
805 .compatible = "maxim,max6625",
806 .data = (void *)max6625
807 },
808 {
809 .compatible = "maxim,max6626",
810 .data = (void *)max6626
811 },
812 {
813 .compatible = "maxim,max31725",
814 .data = (void *)max31725
815 },
816 {
817 .compatible = "maxim,max31726",
818 .data = (void *)max31725
819 },
820 {
821 .compatible = "maxim,mcp980x",
822 .data = (void *)mcp980x
823 },
824 {
825 .compatible = "nxp,pct2075",
826 .data = (void *)pct2075
827 },
828 {
829 .compatible = "st,stds75",
830 .data = (void *)stds75
831 },
832 {
833 .compatible = "st,stlm75",
834 .data = (void *)stlm75
835 },
836 {
837 .compatible = "microchip,tcn75",
838 .data = (void *)tcn75
839 },
840 {
841 .compatible = "ti,tmp100",
842 .data = (void *)tmp100
843 },
844 {
845 .compatible = "ti,tmp101",
846 .data = (void *)tmp101
847 },
848 {
849 .compatible = "ti,tmp105",
850 .data = (void *)tmp105
851 },
852 {
853 .compatible = "ti,tmp112",
854 .data = (void *)tmp112
855 },
856 {
857 .compatible = "ti,tmp175",
858 .data = (void *)tmp175
859 },
860 {
861 .compatible = "ti,tmp275",
862 .data = (void *)tmp275
863 },
864 {
865 .compatible = "ti,tmp75",
866 .data = (void *)tmp75
867 },
868 {
869 .compatible = "ti,tmp75b",
870 .data = (void *)tmp75b
871 },
872 {
873 .compatible = "ti,tmp75c",
874 .data = (void *)tmp75c
875 },
876 {
877 .compatible = "ti,tmp1075",
878 .data = (void *)tmp1075
879 },
880 { },
881};
882MODULE_DEVICE_TABLE(of, lm75_of_match);
883
884#define LM75A_ID 0xA1
885
886/* Return 0 if detection is successful, -ENODEV otherwise */
887static int lm75_detect(struct i2c_client *new_client,
888 struct i2c_board_info *info)
889{
890 struct i2c_adapter *adapter = new_client->adapter;
891 int i;
892 int conf, hyst, os;
893 bool is_lm75a = 0;
894
895 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
896 I2C_FUNC_SMBUS_WORD_DATA))
897 return -ENODEV;
898
899 /*
900 * Now, we do the remaining detection. There is no identification-
901 * dedicated register so we have to rely on several tricks:
902 * unused bits, registers cycling over 8-address boundaries,
903 * addresses 0x04-0x07 returning the last read value.
904 * The cycling+unused addresses combination is not tested,
905 * since it would significantly slow the detection down and would
906 * hardly add any value.
907 *
908 * The National Semiconductor LM75A is different than earlier
909 * LM75s. It has an ID byte of 0xaX (where X is the chip
910 * revision, with 1 being the only revision in existence) in
911 * register 7, and unused registers return 0xff rather than the
912 * last read value.
913 *
914 * Note that this function only detects the original National
915 * Semiconductor LM75 and the LM75A. Clones from other vendors
916 * aren't detected, on purpose, because they are typically never
917 * found on PC hardware. They are found on embedded designs where
918 * they can be instantiated explicitly so detection is not needed.
919 * The absence of identification registers on all these clones
920 * would make their exhaustive detection very difficult and weak,
921 * and odds are that the driver would bind to unsupported devices.
922 */
923
924 /* Unused bits */
925 conf = i2c_smbus_read_byte_data(new_client, 1);
926 if (conf & 0xe0)
927 return -ENODEV;
928
929 /* First check for LM75A */
930 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
931 /*
932 * LM75A returns 0xff on unused registers so
933 * just to be sure we check for that too.
934 */
935 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
936 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
937 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
938 return -ENODEV;
939 is_lm75a = 1;
940 hyst = i2c_smbus_read_byte_data(new_client, 2);
941 os = i2c_smbus_read_byte_data(new_client, 3);
942 } else { /* Traditional style LM75 detection */
943 /* Unused addresses */
944 hyst = i2c_smbus_read_byte_data(new_client, 2);
945 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
946 || i2c_smbus_read_byte_data(new_client, 5) != hyst
947 || i2c_smbus_read_byte_data(new_client, 6) != hyst
948 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
949 return -ENODEV;
950 os = i2c_smbus_read_byte_data(new_client, 3);
951 if (i2c_smbus_read_byte_data(new_client, 4) != os
952 || i2c_smbus_read_byte_data(new_client, 5) != os
953 || i2c_smbus_read_byte_data(new_client, 6) != os
954 || i2c_smbus_read_byte_data(new_client, 7) != os)
955 return -ENODEV;
956 }
957 /*
958 * It is very unlikely that this is a LM75 if both
959 * hysteresis and temperature limit registers are 0.
960 */
961 if (hyst == 0 && os == 0)
962 return -ENODEV;
963
964 /* Addresses cycling */
965 for (i = 8; i <= 248; i += 40) {
966 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
967 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
968 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
969 return -ENODEV;
970 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
971 != LM75A_ID)
972 return -ENODEV;
973 }
974
975 strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
976
977 return 0;
978}
979
980#ifdef CONFIG_PM
981static int lm75_suspend(struct device *dev)
982{
983 int status;
984 struct i2c_client *client = to_i2c_client(dev);
985
986 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
987 if (status < 0) {
988 dev_dbg(&client->dev, "Can't read config? %d\n", status);
989 return status;
990 }
991 status = status | LM75_SHUTDOWN;
992 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
993 return 0;
994}
995
996static int lm75_resume(struct device *dev)
997{
998 int status;
999 struct i2c_client *client = to_i2c_client(dev);
1000
1001 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
1002 if (status < 0) {
1003 dev_dbg(&client->dev, "Can't read config? %d\n", status);
1004 return status;
1005 }
1006 status = status & ~LM75_SHUTDOWN;
1007 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
1008 return 0;
1009}
1010
1011static const struct dev_pm_ops lm75_dev_pm_ops = {
1012 .suspend = lm75_suspend,
1013 .resume = lm75_resume,
1014};
1015#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
1016#else
1017#define LM75_DEV_PM_OPS NULL
1018#endif /* CONFIG_PM */
1019
1020static struct i2c_driver lm75_driver = {
1021 .class = I2C_CLASS_HWMON,
1022 .driver = {
1023 .name = "lm75",
1024 .of_match_table = of_match_ptr(lm75_of_match),
1025 .pm = LM75_DEV_PM_OPS,
1026 },
1027 .probe = lm75_probe,
1028 .id_table = lm75_ids,
1029 .detect = lm75_detect,
1030 .address_list = normal_i2c,
1031};
1032
1033module_i2c_driver(lm75_driver);
1034
1035MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
1036MODULE_DESCRIPTION("LM75 driver");
1037MODULE_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/mutex.h>
30#include <linux/of.h>
31#include <linux/thermal.h>
32#include "lm75.h"
33
34
35/*
36 * This driver handles the LM75 and compatible digital temperature sensors.
37 */
38
39enum lm75_type { /* keep sorted in alphabetical order */
40 adt75,
41 ds1775,
42 ds75,
43 ds7505,
44 g751,
45 lm75,
46 lm75a,
47 max6625,
48 max6626,
49 mcp980x,
50 stds75,
51 tcn75,
52 tmp100,
53 tmp101,
54 tmp105,
55 tmp175,
56 tmp275,
57 tmp75,
58};
59
60/* Addresses scanned */
61static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
62 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
63
64
65/* The LM75 registers */
66#define LM75_REG_CONF 0x01
67static const u8 LM75_REG_TEMP[3] = {
68 0x00, /* input */
69 0x03, /* max */
70 0x02, /* hyst */
71};
72
73/* Each client has this additional data */
74struct lm75_data {
75 struct device *hwmon_dev;
76 struct thermal_zone_device *tz;
77 struct mutex update_lock;
78 u8 orig_conf;
79 u8 resolution; /* In bits, between 9 and 12 */
80 u8 resolution_limits;
81 char valid; /* !=0 if registers are valid */
82 unsigned long last_updated; /* In jiffies */
83 unsigned long sample_time; /* In jiffies */
84 s16 temp[3]; /* Register values,
85 0 = input
86 1 = max
87 2 = hyst */
88};
89
90static int lm75_read_value(struct i2c_client *client, u8 reg);
91static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
92static struct lm75_data *lm75_update_device(struct device *dev);
93
94
95/*-----------------------------------------------------------------------*/
96
97static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
98{
99 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
100}
101
102/* sysfs attributes for hwmon */
103
104static int lm75_read_temp(void *dev, long *temp)
105{
106 struct lm75_data *data = lm75_update_device(dev);
107
108 if (IS_ERR(data))
109 return PTR_ERR(data);
110
111 *temp = lm75_reg_to_mc(data->temp[0], data->resolution);
112
113 return 0;
114}
115
116static ssize_t show_temp(struct device *dev, struct device_attribute *da,
117 char *buf)
118{
119 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
120 struct lm75_data *data = lm75_update_device(dev);
121
122 if (IS_ERR(data))
123 return PTR_ERR(data);
124
125 return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
126 data->resolution));
127}
128
129static ssize_t set_temp(struct device *dev, struct device_attribute *da,
130 const char *buf, size_t count)
131{
132 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
133 struct i2c_client *client = to_i2c_client(dev);
134 struct lm75_data *data = i2c_get_clientdata(client);
135 int nr = attr->index;
136 long temp;
137 int error;
138 u8 resolution;
139
140 error = kstrtol(buf, 10, &temp);
141 if (error)
142 return error;
143
144 /*
145 * Resolution of limit registers is assumed to be the same as the
146 * temperature input register resolution unless given explicitly.
147 */
148 if (attr->index && data->resolution_limits)
149 resolution = data->resolution_limits;
150 else
151 resolution = data->resolution;
152
153 mutex_lock(&data->update_lock);
154 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
155 data->temp[nr] = DIV_ROUND_CLOSEST(temp << (resolution - 8),
156 1000) << (16 - resolution);
157 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
158 mutex_unlock(&data->update_lock);
159 return count;
160}
161
162static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
163 show_temp, set_temp, 1);
164static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
165 show_temp, set_temp, 2);
166static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
167
168static struct attribute *lm75_attributes[] = {
169 &sensor_dev_attr_temp1_input.dev_attr.attr,
170 &sensor_dev_attr_temp1_max.dev_attr.attr,
171 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
172
173 NULL
174};
175
176static const struct attribute_group lm75_group = {
177 .attrs = lm75_attributes,
178};
179
180/*-----------------------------------------------------------------------*/
181
182/* device probe and removal */
183
184static int
185lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
186{
187 struct lm75_data *data;
188 int status;
189 u8 set_mask, clr_mask;
190 int new;
191 enum lm75_type kind = id->driver_data;
192
193 if (!i2c_check_functionality(client->adapter,
194 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
195 return -EIO;
196
197 data = devm_kzalloc(&client->dev, sizeof(struct lm75_data), GFP_KERNEL);
198 if (!data)
199 return -ENOMEM;
200
201 i2c_set_clientdata(client, data);
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;
208 clr_mask = LM75_SHUTDOWN; /* continuous conversions */
209
210 switch (kind) {
211 case adt75:
212 clr_mask |= 1 << 5; /* not one-shot mode */
213 data->resolution = 12;
214 data->sample_time = HZ / 8;
215 break;
216 case ds1775:
217 case ds75:
218 case stds75:
219 clr_mask |= 3 << 5;
220 set_mask |= 2 << 5; /* 11-bit mode */
221 data->resolution = 11;
222 data->sample_time = HZ;
223 break;
224 case ds7505:
225 set_mask |= 3 << 5; /* 12-bit mode */
226 data->resolution = 12;
227 data->sample_time = HZ / 4;
228 break;
229 case g751:
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;
247 break;
248 case mcp980x:
249 data->resolution_limits = 9;
250 /* fall through */
251 case tmp100:
252 case tmp101:
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;
258 case tmp105:
259 case tmp175:
260 case tmp275:
261 case tmp75:
262 set_mask |= 3 << 5; /* 12-bit mode */
263 clr_mask |= 1 << 7; /* not one-shot mode */
264 data->resolution = 12;
265 data->sample_time = HZ / 2;
266 break;
267 }
268
269 /* configure as specified */
270 status = lm75_read_value(client, LM75_REG_CONF);
271 if (status < 0) {
272 dev_dbg(&client->dev, "Can't read config? %d\n", status);
273 return status;
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);
280 dev_dbg(&client->dev, "Config %02x\n", new);
281
282 /* Register sysfs hooks */
283 status = sysfs_create_group(&client->dev.kobj, &lm75_group);
284 if (status)
285 return status;
286
287 data->hwmon_dev = hwmon_device_register(&client->dev);
288 if (IS_ERR(data->hwmon_dev)) {
289 status = PTR_ERR(data->hwmon_dev);
290 goto exit_remove;
291 }
292
293 data->tz = thermal_zone_of_sensor_register(&client->dev,
294 0,
295 &client->dev,
296 lm75_read_temp, NULL);
297 if (IS_ERR(data->tz))
298 data->tz = NULL;
299
300 dev_info(&client->dev, "%s: sensor '%s'\n",
301 dev_name(data->hwmon_dev), client->name);
302
303 return 0;
304
305exit_remove:
306 sysfs_remove_group(&client->dev.kobj, &lm75_group);
307 return status;
308}
309
310static int lm75_remove(struct i2c_client *client)
311{
312 struct lm75_data *data = i2c_get_clientdata(client);
313
314 thermal_zone_of_sensor_unregister(&client->dev, data->tz);
315 hwmon_device_unregister(data->hwmon_dev);
316 sysfs_remove_group(&client->dev.kobj, &lm75_group);
317 lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
318 return 0;
319}
320
321static const struct i2c_device_id lm75_ids[] = {
322 { "adt75", adt75, },
323 { "ds1775", ds1775, },
324 { "ds75", ds75, },
325 { "ds7505", ds7505, },
326 { "g751", g751, },
327 { "lm75", lm75, },
328 { "lm75a", lm75a, },
329 { "max6625", max6625, },
330 { "max6626", max6626, },
331 { "mcp980x", mcp980x, },
332 { "stds75", stds75, },
333 { "tcn75", tcn75, },
334 { "tmp100", tmp100, },
335 { "tmp101", tmp101, },
336 { "tmp105", tmp105, },
337 { "tmp175", tmp175, },
338 { "tmp275", tmp275, },
339 { "tmp75", tmp75, },
340 { /* LIST END */ }
341};
342MODULE_DEVICE_TABLE(i2c, lm75_ids);
343
344#define LM75A_ID 0xA1
345
346/* Return 0 if detection is successful, -ENODEV otherwise */
347static int lm75_detect(struct i2c_client *new_client,
348 struct i2c_board_info *info)
349{
350 struct i2c_adapter *adapter = new_client->adapter;
351 int i;
352 int conf, hyst, os;
353 bool is_lm75a = 0;
354
355 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
356 I2C_FUNC_SMBUS_WORD_DATA))
357 return -ENODEV;
358
359 /*
360 * Now, we do the remaining detection. There is no identification-
361 * dedicated register so we have to rely on several tricks:
362 * unused bits, registers cycling over 8-address boundaries,
363 * addresses 0x04-0x07 returning the last read value.
364 * The cycling+unused addresses combination is not tested,
365 * since it would significantly slow the detection down and would
366 * hardly add any value.
367 *
368 * The National Semiconductor LM75A is different than earlier
369 * LM75s. It has an ID byte of 0xaX (where X is the chip
370 * revision, with 1 being the only revision in existence) in
371 * register 7, and unused registers return 0xff rather than the
372 * last read value.
373 *
374 * Note that this function only detects the original National
375 * Semiconductor LM75 and the LM75A. Clones from other vendors
376 * aren't detected, on purpose, because they are typically never
377 * found on PC hardware. They are found on embedded designs where
378 * they can be instantiated explicitly so detection is not needed.
379 * The absence of identification registers on all these clones
380 * would make their exhaustive detection very difficult and weak,
381 * and odds are that the driver would bind to unsupported devices.
382 */
383
384 /* Unused bits */
385 conf = i2c_smbus_read_byte_data(new_client, 1);
386 if (conf & 0xe0)
387 return -ENODEV;
388
389 /* First check for LM75A */
390 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
391 /* LM75A returns 0xff on unused registers so
392 just to be sure we check for that too. */
393 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
394 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
395 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
396 return -ENODEV;
397 is_lm75a = 1;
398 hyst = i2c_smbus_read_byte_data(new_client, 2);
399 os = i2c_smbus_read_byte_data(new_client, 3);
400 } else { /* Traditional style LM75 detection */
401 /* Unused addresses */
402 hyst = i2c_smbus_read_byte_data(new_client, 2);
403 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
404 || i2c_smbus_read_byte_data(new_client, 5) != hyst
405 || i2c_smbus_read_byte_data(new_client, 6) != hyst
406 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
407 return -ENODEV;
408 os = i2c_smbus_read_byte_data(new_client, 3);
409 if (i2c_smbus_read_byte_data(new_client, 4) != os
410 || i2c_smbus_read_byte_data(new_client, 5) != os
411 || i2c_smbus_read_byte_data(new_client, 6) != os
412 || i2c_smbus_read_byte_data(new_client, 7) != os)
413 return -ENODEV;
414 }
415
416 /* Addresses cycling */
417 for (i = 8; i <= 248; i += 40) {
418 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
419 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
420 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
421 return -ENODEV;
422 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
423 != LM75A_ID)
424 return -ENODEV;
425 }
426
427 strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
428
429 return 0;
430}
431
432#ifdef CONFIG_PM
433static int lm75_suspend(struct device *dev)
434{
435 int status;
436 struct i2c_client *client = to_i2c_client(dev);
437 status = lm75_read_value(client, LM75_REG_CONF);
438 if (status < 0) {
439 dev_dbg(&client->dev, "Can't read config? %d\n", status);
440 return status;
441 }
442 status = status | LM75_SHUTDOWN;
443 lm75_write_value(client, LM75_REG_CONF, status);
444 return 0;
445}
446
447static int lm75_resume(struct device *dev)
448{
449 int status;
450 struct i2c_client *client = to_i2c_client(dev);
451 status = lm75_read_value(client, LM75_REG_CONF);
452 if (status < 0) {
453 dev_dbg(&client->dev, "Can't read config? %d\n", status);
454 return status;
455 }
456 status = status & ~LM75_SHUTDOWN;
457 lm75_write_value(client, LM75_REG_CONF, status);
458 return 0;
459}
460
461static const struct dev_pm_ops lm75_dev_pm_ops = {
462 .suspend = lm75_suspend,
463 .resume = lm75_resume,
464};
465#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
466#else
467#define LM75_DEV_PM_OPS NULL
468#endif /* CONFIG_PM */
469
470static struct i2c_driver lm75_driver = {
471 .class = I2C_CLASS_HWMON,
472 .driver = {
473 .name = "lm75",
474 .pm = LM75_DEV_PM_OPS,
475 },
476 .probe = lm75_probe,
477 .remove = lm75_remove,
478 .id_table = lm75_ids,
479 .detect = lm75_detect,
480 .address_list = normal_i2c,
481};
482
483/*-----------------------------------------------------------------------*/
484
485/* register access */
486
487/*
488 * All registers are word-sized, except for the configuration register.
489 * LM75 uses a high-byte first convention, which is exactly opposite to
490 * the SMBus standard.
491 */
492static int lm75_read_value(struct i2c_client *client, u8 reg)
493{
494 if (reg == LM75_REG_CONF)
495 return i2c_smbus_read_byte_data(client, reg);
496 else
497 return i2c_smbus_read_word_swapped(client, reg);
498}
499
500static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
501{
502 if (reg == LM75_REG_CONF)
503 return i2c_smbus_write_byte_data(client, reg, value);
504 else
505 return i2c_smbus_write_word_swapped(client, reg, value);
506}
507
508static struct lm75_data *lm75_update_device(struct device *dev)
509{
510 struct i2c_client *client = to_i2c_client(dev);
511 struct lm75_data *data = i2c_get_clientdata(client);
512 struct lm75_data *ret = data;
513
514 mutex_lock(&data->update_lock);
515
516 if (time_after(jiffies, data->last_updated + data->sample_time)
517 || !data->valid) {
518 int i;
519 dev_dbg(&client->dev, "Starting lm75 update\n");
520
521 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
522 int status;
523
524 status = lm75_read_value(client, LM75_REG_TEMP[i]);
525 if (unlikely(status < 0)) {
526 dev_dbg(dev,
527 "LM75: Failed to read value: reg %d, error %d\n",
528 LM75_REG_TEMP[i], status);
529 ret = ERR_PTR(status);
530 data->valid = 0;
531 goto abort;
532 }
533 data->temp[i] = status;
534 }
535 data->last_updated = jiffies;
536 data->valid = 1;
537 }
538
539abort:
540 mutex_unlock(&data->update_lock);
541 return ret;
542}
543
544module_i2c_driver(lm75_driver);
545
546MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
547MODULE_DESCRIPTION("LM75 driver");
548MODULE_LICENSE("GPL");