1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * max6639.c - Support for Maxim MAX6639
4 *
5 * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
6 *
7 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
8 *
9 * based on the initial MAX6639 support from semptian.net
10 * by He Changqing <hechangqing@semptian.com>
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/jiffies.h>
17#include <linux/i2c.h>
18#include <linux/hwmon.h>
19#include <linux/err.h>
20#include <linux/regmap.h>
21#include <linux/util_macros.h>
22
23/* Addresses to scan */
24static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
25
26/* The MAX6639 registers, valid channel numbers: 0, 1 */
27#define MAX6639_REG_TEMP(ch) (0x00 + (ch))
28#define MAX6639_REG_STATUS 0x02
29#define MAX6639_REG_OUTPUT_MASK 0x03
30#define MAX6639_REG_GCONFIG 0x04
31#define MAX6639_REG_TEMP_EXT(ch) (0x05 + (ch))
32#define MAX6639_REG_ALERT_LIMIT(ch) (0x08 + (ch))
33#define MAX6639_REG_OT_LIMIT(ch) (0x0A + (ch))
34#define MAX6639_REG_THERM_LIMIT(ch) (0x0C + (ch))
35#define MAX6639_REG_FAN_CONFIG1(ch) (0x10 + (ch) * 4)
36#define MAX6639_REG_FAN_CONFIG2a(ch) (0x11 + (ch) * 4)
37#define MAX6639_REG_FAN_CONFIG2b(ch) (0x12 + (ch) * 4)
38#define MAX6639_REG_FAN_CONFIG3(ch) (0x13 + (ch) * 4)
39#define MAX6639_REG_FAN_CNT(ch) (0x20 + (ch))
40#define MAX6639_REG_TARGET_CNT(ch) (0x22 + (ch))
41#define MAX6639_REG_FAN_PPR(ch) (0x24 + (ch))
42#define MAX6639_REG_TARGTDUTY(ch) (0x26 + (ch))
43#define MAX6639_REG_FAN_START_TEMP(ch) (0x28 + (ch))
44#define MAX6639_REG_DEVID 0x3D
45#define MAX6639_REG_MANUID 0x3E
46#define MAX6639_REG_DEVREV 0x3F
47
48/* Register bits */
49#define MAX6639_GCONFIG_STANDBY 0x80
50#define MAX6639_GCONFIG_POR 0x40
51#define MAX6639_GCONFIG_DISABLE_TIMEOUT 0x20
52#define MAX6639_GCONFIG_CH2_LOCAL 0x10
53#define MAX6639_GCONFIG_PWM_FREQ_HI 0x08
54
55#define MAX6639_FAN_CONFIG1_PWM 0x80
56#define MAX6639_FAN_CONFIG3_FREQ_MASK 0x03
57#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED 0x40
58
59#define MAX6639_NUM_CHANNELS 2
60
61static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
62
63/* Supported PWM frequency */
64static const unsigned int freq_table[] = { 20, 33, 50, 100, 5000, 8333, 12500,
65 25000 };
66
67#define FAN_FROM_REG(val, rpm_range) ((val) == 0 || (val) == 255 ? \
68 0 : (rpm_ranges[rpm_range] * 30) / (val))
69#define TEMP_LIMIT_TO_REG(val) clamp_val((val) / 1000, 0, 255)
70
71/*
72 * Client data (each client gets its own)
73 */
74struct max6639_data {
75 struct regmap *regmap;
76
77 /* Register values initialized only once */
78 u8 ppr[MAX6639_NUM_CHANNELS]; /* Pulses per rotation 0..3 for 1..4 ppr */
79 u8 rpm_range[MAX6639_NUM_CHANNELS]; /* Index in above rpm_ranges table */
80 u32 target_rpm[MAX6639_NUM_CHANNELS];
81
82 /* Optional regulator for FAN supply */
83 struct regulator *reg;
84};
85
86static int max6639_temp_read_input(struct device *dev, int channel, long *temp)
87{
88 u32 regs[2] = { MAX6639_REG_TEMP_EXT(channel), MAX6639_REG_TEMP(channel) };
89 struct max6639_data *data = dev_get_drvdata(dev);
90 u8 regvals[2];
91 int res;
92
93 res = regmap_multi_reg_read(map: data->regmap, reg: regs, val: regvals, val_count: 2);
94 if (res < 0)
95 return res;
96
97 *temp = ((regvals[0] >> 5) | (regvals[1] << 3)) * 125;
98
99 return 0;
100}
101
102static int max6639_temp_read_fault(struct device *dev, int channel, long *fault)
103{
104 struct max6639_data *data = dev_get_drvdata(dev);
105 unsigned int val;
106 int res;
107
108 res = regmap_read(map: data->regmap, MAX6639_REG_TEMP_EXT(channel), val: &val);
109 if (res < 0)
110 return res;
111
112 *fault = val & 1;
113
114 return 0;
115}
116
117static int max6639_temp_read_max(struct device *dev, int channel, long *max)
118{
119 struct max6639_data *data = dev_get_drvdata(dev);
120 unsigned int val;
121 int res;
122
123 res = regmap_read(map: data->regmap, MAX6639_REG_THERM_LIMIT(channel), val: &val);
124 if (res < 0)
125 return res;
126
127 *max = (long)val * 1000;
128
129 return 0;
130}
131
132static int max6639_temp_read_crit(struct device *dev, int channel, long *crit)
133{
134 struct max6639_data *data = dev_get_drvdata(dev);
135 unsigned int val;
136 int res;
137
138 res = regmap_read(map: data->regmap, MAX6639_REG_ALERT_LIMIT(channel), val: &val);
139 if (res < 0)
140 return res;
141
142 *crit = (long)val * 1000;
143
144 return 0;
145}
146
147static int max6639_temp_read_emergency(struct device *dev, int channel, long *emerg)
148{
149 struct max6639_data *data = dev_get_drvdata(dev);
150 unsigned int val;
151 int res;
152
153 res = regmap_read(map: data->regmap, MAX6639_REG_OT_LIMIT(channel), val: &val);
154 if (res < 0)
155 return res;
156
157 *emerg = (long)val * 1000;
158
159 return 0;
160}
161
162static int max6639_get_status(struct device *dev, unsigned int *status)
163{
164 struct max6639_data *data = dev_get_drvdata(dev);
165 unsigned int val;
166 int res;
167
168 res = regmap_read(map: data->regmap, MAX6639_REG_STATUS, val: &val);
169 if (res < 0)
170 return res;
171
172 *status = val;
173
174 return 0;
175}
176
177static int max6639_temp_set_max(struct max6639_data *data, int channel, long val)
178{
179 int res;
180
181 res = regmap_write(map: data->regmap, MAX6639_REG_THERM_LIMIT(channel),
182 TEMP_LIMIT_TO_REG(val));
183 return res;
184}
185
186static int max6639_temp_set_crit(struct max6639_data *data, int channel, long val)
187{
188 int res;
189
190 res = regmap_write(map: data->regmap, MAX6639_REG_ALERT_LIMIT(channel), TEMP_LIMIT_TO_REG(val));
191
192 return res;
193}
194
195static int max6639_temp_set_emergency(struct max6639_data *data, int channel, long val)
196{
197 int res;
198
199 res = regmap_write(map: data->regmap, MAX6639_REG_OT_LIMIT(channel), TEMP_LIMIT_TO_REG(val));
200
201 return res;
202}
203
204static int max6639_read_fan(struct device *dev, u32 attr, int channel,
205 long *fan_val)
206{
207 struct max6639_data *data = dev_get_drvdata(dev);
208 unsigned int val;
209 int res;
210
211 switch (attr) {
212 case hwmon_fan_input:
213 res = regmap_read(map: data->regmap, MAX6639_REG_FAN_CNT(channel), val: &val);
214 if (res < 0)
215 return res;
216 *fan_val = FAN_FROM_REG(val, data->rpm_range[channel]);
217 return 0;
218 case hwmon_fan_fault:
219 res = max6639_get_status(dev, status: &val);
220 if (res < 0)
221 return res;
222 *fan_val = !!(val & BIT(1 - channel));
223 return 0;
224 case hwmon_fan_pulses:
225 *fan_val = data->ppr[channel];
226 return 0;
227 default:
228 return -EOPNOTSUPP;
229 }
230}
231
232static int max6639_set_ppr(struct max6639_data *data, int channel, u8 ppr)
233{
234 /* Decrement the PPR value and shift left by 6 to match the register format */
235 return regmap_write(map: data->regmap, MAX6639_REG_FAN_PPR(channel), val: ppr-- << 6);
236}
237
238static int max6639_write_fan(struct device *dev, u32 attr, int channel,
239 long val)
240{
241 struct max6639_data *data = dev_get_drvdata(dev);
242 int err;
243
244 switch (attr) {
245 case hwmon_fan_pulses:
246 if (val <= 0 || val > 4)
247 return -EINVAL;
248
249 /* Set Fan pulse per revolution */
250 err = max6639_set_ppr(data, channel, ppr: val);
251 if (err < 0)
252 return err;
253 data->ppr[channel] = val;
254 return 0;
255 default:
256 return -EOPNOTSUPP;
257 }
258}
259
260static umode_t max6639_fan_is_visible(const void *_data, u32 attr, int channel)
261{
262 switch (attr) {
263 case hwmon_fan_input:
264 case hwmon_fan_fault:
265 return 0444;
266 case hwmon_fan_pulses:
267 return 0644;
268 default:
269 return 0;
270 }
271}
272
273static int max6639_read_pwm(struct device *dev, u32 attr, int channel,
274 long *pwm_val)
275{
276 u32 regs[2] = { MAX6639_REG_FAN_CONFIG3(channel), MAX6639_REG_GCONFIG };
277 struct max6639_data *data = dev_get_drvdata(dev);
278 unsigned int val;
279 u8 regvals[2];
280 int res;
281 u8 i;
282
283 switch (attr) {
284 case hwmon_pwm_input:
285 res = regmap_read(map: data->regmap, MAX6639_REG_TARGTDUTY(channel), val: &val);
286 if (res < 0)
287 return res;
288 *pwm_val = val * 255 / 120;
289 return 0;
290 case hwmon_pwm_freq:
291 res = regmap_multi_reg_read(map: data->regmap, reg: regs, val: regvals, val_count: 2);
292 if (res < 0)
293 return res;
294 i = regvals[0] & MAX6639_FAN_CONFIG3_FREQ_MASK;
295 if (regvals[1] & MAX6639_GCONFIG_PWM_FREQ_HI)
296 i |= 0x4;
297 *pwm_val = freq_table[i];
298 return 0;
299 default:
300 return -EOPNOTSUPP;
301 }
302}
303
304static int max6639_write_pwm(struct device *dev, u32 attr, int channel,
305 long val)
306{
307 struct max6639_data *data = dev_get_drvdata(dev);
308 int err;
309 u8 i;
310
311 switch (attr) {
312 case hwmon_pwm_input:
313 if (val < 0 || val > 255)
314 return -EINVAL;
315 return regmap_write(map: data->regmap, MAX6639_REG_TARGTDUTY(channel),
316 val: val * 120 / 255);
317 case hwmon_pwm_freq:
318 val = clamp_val(val, 0, 25000);
319
320 i = find_closest(val, freq_table, ARRAY_SIZE(freq_table));
321
322 err = regmap_update_bits(map: data->regmap, MAX6639_REG_FAN_CONFIG3(channel),
323 MAX6639_FAN_CONFIG3_FREQ_MASK, val: i);
324 if (err < 0)
325 return err;
326
327 if (i >> 2)
328 err = regmap_set_bits(map: data->regmap, MAX6639_REG_GCONFIG,
329 MAX6639_GCONFIG_PWM_FREQ_HI);
330 else
331 err = regmap_clear_bits(map: data->regmap, MAX6639_REG_GCONFIG,
332 MAX6639_GCONFIG_PWM_FREQ_HI);
333
334 return err;
335 default:
336 return -EOPNOTSUPP;
337 }
338}
339
340static umode_t max6639_pwm_is_visible(const void *_data, u32 attr, int channel)
341{
342 switch (attr) {
343 case hwmon_pwm_input:
344 case hwmon_pwm_freq:
345 return 0644;
346 default:
347 return 0;
348 }
349}
350
351static int max6639_read_temp(struct device *dev, u32 attr, int channel,
352 long *val)
353{
354 unsigned int status;
355 int res;
356
357 switch (attr) {
358 case hwmon_temp_input:
359 res = max6639_temp_read_input(dev, channel, temp: val);
360 return res;
361 case hwmon_temp_fault:
362 res = max6639_temp_read_fault(dev, channel, fault: val);
363 return res;
364 case hwmon_temp_max:
365 res = max6639_temp_read_max(dev, channel, max: val);
366 return res;
367 case hwmon_temp_crit:
368 res = max6639_temp_read_crit(dev, channel, crit: val);
369 return res;
370 case hwmon_temp_emergency:
371 res = max6639_temp_read_emergency(dev, channel, emerg: val);
372 return res;
373 case hwmon_temp_max_alarm:
374 res = max6639_get_status(dev, status: &status);
375 if (res < 0)
376 return res;
377 *val = !!(status & BIT(3 - channel));
378 return 0;
379 case hwmon_temp_crit_alarm:
380 res = max6639_get_status(dev, status: &status);
381 if (res < 0)
382 return res;
383 *val = !!(status & BIT(7 - channel));
384 return 0;
385 case hwmon_temp_emergency_alarm:
386 res = max6639_get_status(dev, status: &status);
387 if (res < 0)
388 return res;
389 *val = !!(status & BIT(5 - channel));
390 return 0;
391 default:
392 return -EOPNOTSUPP;
393 }
394}
395
396static int max6639_write_temp(struct device *dev, u32 attr, int channel,
397 long val)
398{
399 struct max6639_data *data = dev_get_drvdata(dev);
400
401 switch (attr) {
402 case hwmon_temp_max:
403 return max6639_temp_set_max(data, channel, val);
404 case hwmon_temp_crit:
405 return max6639_temp_set_crit(data, channel, val);
406 case hwmon_temp_emergency:
407 return max6639_temp_set_emergency(data, channel, val);
408 default:
409 return -EOPNOTSUPP;
410 }
411}
412
413static umode_t max6639_temp_is_visible(const void *_data, u32 attr, int channel)
414{
415 switch (attr) {
416 case hwmon_temp_input:
417 case hwmon_temp_fault:
418 case hwmon_temp_max_alarm:
419 case hwmon_temp_crit_alarm:
420 case hwmon_temp_emergency_alarm:
421 return 0444;
422 case hwmon_temp_max:
423 case hwmon_temp_crit:
424 case hwmon_temp_emergency:
425 return 0644;
426 default:
427 return 0;
428 }
429}
430
431static int max6639_read(struct device *dev, enum hwmon_sensor_types type,
432 u32 attr, int channel, long *val)
433{
434 switch (type) {
435 case hwmon_fan:
436 return max6639_read_fan(dev, attr, channel, fan_val: val);
437 case hwmon_pwm:
438 return max6639_read_pwm(dev, attr, channel, pwm_val: val);
439 case hwmon_temp:
440 return max6639_read_temp(dev, attr, channel, val);
441 default:
442 return -EOPNOTSUPP;
443 }
444}
445
446static int max6639_write(struct device *dev, enum hwmon_sensor_types type,
447 u32 attr, int channel, long val)
448{
449 switch (type) {
450 case hwmon_fan:
451 return max6639_write_fan(dev, attr, channel, val);
452 case hwmon_pwm:
453 return max6639_write_pwm(dev, attr, channel, val);
454 case hwmon_temp:
455 return max6639_write_temp(dev, attr, channel, val);
456 default:
457 return -EOPNOTSUPP;
458 }
459}
460
461static umode_t max6639_is_visible(const void *data,
462 enum hwmon_sensor_types type,
463 u32 attr, int channel)
464{
465 switch (type) {
466 case hwmon_fan:
467 return max6639_fan_is_visible(data: data, attr, channel);
468 case hwmon_pwm:
469 return max6639_pwm_is_visible(data: data, attr, channel);
470 case hwmon_temp:
471 return max6639_temp_is_visible(data: data, attr, channel);
472 default:
473 return 0;
474 }
475}
476
477static const struct hwmon_channel_info * const max6639_info[] = {
478 HWMON_CHANNEL_INFO(fan,
479 HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_PULSES,
480 HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_PULSES),
481 HWMON_CHANNEL_INFO(pwm,
482 HWMON_PWM_INPUT | HWMON_PWM_FREQ,
483 HWMON_PWM_INPUT | HWMON_PWM_FREQ),
484 HWMON_CHANNEL_INFO(temp,
485 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_MAX | HWMON_T_MAX_ALARM |
486 HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_EMERGENCY |
487 HWMON_T_EMERGENCY_ALARM,
488 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_MAX | HWMON_T_MAX_ALARM |
489 HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_EMERGENCY |
490 HWMON_T_EMERGENCY_ALARM),
491 NULL
492};
493
494static const struct hwmon_ops max6639_hwmon_ops = {
495 .is_visible = max6639_is_visible,
496 .read = max6639_read,
497 .write = max6639_write,
498};
499
500static const struct hwmon_chip_info max6639_chip_info = {
501 .ops = &max6639_hwmon_ops,
502 .info = max6639_info,
503};
504
505/*
506 * returns respective index in rpm_ranges table
507 * 1 by default on invalid range
508 */
509static int rpm_range_to_reg(int range)
510{
511 int i;
512
513 for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
514 if (rpm_ranges[i] == range)
515 return i;
516 }
517
518 return 1; /* default: 4000 RPM */
519}
520
521static int max6639_probe_child_from_dt(struct i2c_client *client,
522 struct device_node *child,
523 struct max6639_data *data)
524
525{
526 struct device *dev = &client->dev;
527 u32 i;
528 int err, val;
529
530 err = of_property_read_u32(np: child, propname: "reg", out_value: &i);
531 if (err) {
532 dev_err(dev, "missing reg property of %pOFn\n", child);
533 return err;
534 }
535
536 if (i > 1) {
537 dev_err(dev, "Invalid fan index reg %d\n", i);
538 return -EINVAL;
539 }
540
541 err = of_property_read_u32(np: child, propname: "pulses-per-revolution", out_value: &val);
542 if (!err) {
543 if (val < 1 || val > 5) {
544 dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val, child);
545 return -EINVAL;
546 }
547 data->ppr[i] = val;
548 }
549
550 err = of_property_read_u32(np: child, propname: "max-rpm", out_value: &val);
551 if (!err)
552 data->rpm_range[i] = rpm_range_to_reg(range: val);
553
554 err = of_property_read_u32(np: child, propname: "target-rpm", out_value: &val);
555 if (!err)
556 data->target_rpm[i] = val;
557
558 return 0;
559}
560
561static int max6639_init_client(struct i2c_client *client,
562 struct max6639_data *data)
563{
564 struct device *dev = &client->dev;
565 const struct device_node *np = dev->of_node;
566 struct device_node *child;
567 int i, err;
568 u8 target_duty;
569
570 /* Reset chip to default values, see below for GCONFIG setup */
571 err = regmap_write(map: data->regmap, MAX6639_REG_GCONFIG, MAX6639_GCONFIG_POR);
572 if (err)
573 return err;
574
575 /* Fans pulse per revolution is 2 by default */
576 data->ppr[0] = 2;
577 data->ppr[1] = 2;
578
579 /* default: 4000 RPM */
580 data->rpm_range[0] = 1;
581 data->rpm_range[1] = 1;
582 data->target_rpm[0] = 4000;
583 data->target_rpm[1] = 4000;
584
585 for_each_child_of_node(np, child) {
586 if (strcmp(child->name, "fan"))
587 continue;
588
589 err = max6639_probe_child_from_dt(client, child, data);
590 if (err) {
591 of_node_put(node: child);
592 return err;
593 }
594 }
595
596 for (i = 0; i < MAX6639_NUM_CHANNELS; i++) {
597 err = regmap_set_bits(map: data->regmap, MAX6639_REG_OUTPUT_MASK, BIT(1 - i));
598 if (err)
599 return err;
600
601 /* Set Fan pulse per revolution */
602 err = max6639_set_ppr(data, channel: i, ppr: data->ppr[i]);
603 if (err)
604 return err;
605
606 /* Fans config PWM, RPM */
607 err = regmap_write(map: data->regmap, MAX6639_REG_FAN_CONFIG1(i),
608 MAX6639_FAN_CONFIG1_PWM | data->rpm_range[i]);
609 if (err)
610 return err;
611
612 /* Fans PWM polarity high by default */
613 err = regmap_write(map: data->regmap, MAX6639_REG_FAN_CONFIG2a(i), val: 0x00);
614 if (err)
615 return err;
616
617 /*
618 * /THERM full speed enable,
619 * PWM frequency 25kHz, see also GCONFIG below
620 */
621 err = regmap_write(map: data->regmap, MAX6639_REG_FAN_CONFIG3(i),
622 MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
623 if (err)
624 return err;
625
626 /* Max. temp. 80C/90C/100C */
627 err = regmap_write(map: data->regmap, MAX6639_REG_THERM_LIMIT(i), val: 80);
628 if (err)
629 return err;
630 err = regmap_write(map: data->regmap, MAX6639_REG_ALERT_LIMIT(i), val: 90);
631 if (err)
632 return err;
633 err = regmap_write(map: data->regmap, MAX6639_REG_OT_LIMIT(i), val: 100);
634 if (err)
635 return err;
636
637 /* Set PWM based on target RPM if specified */
638 if (data->target_rpm[i] > rpm_ranges[data->rpm_range[i]])
639 data->target_rpm[i] = rpm_ranges[data->rpm_range[i]];
640
641 target_duty = 120 * data->target_rpm[i] / rpm_ranges[data->rpm_range[i]];
642 err = regmap_write(map: data->regmap, MAX6639_REG_TARGTDUTY(i), val: target_duty);
643 if (err)
644 return err;
645 }
646 /* Start monitoring */
647 return regmap_write(map: data->regmap, MAX6639_REG_GCONFIG,
648 MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
649 MAX6639_GCONFIG_PWM_FREQ_HI);
650
651}
652
653/* Return 0 if detection is successful, -ENODEV otherwise */
654static int max6639_detect(struct i2c_client *client,
655 struct i2c_board_info *info)
656{
657 struct i2c_adapter *adapter = client->adapter;
658 int dev_id, manu_id;
659
660 if (!i2c_check_functionality(adap: adapter, I2C_FUNC_SMBUS_BYTE_DATA))
661 return -ENODEV;
662
663 /* Actual detection via device and manufacturer ID */
664 dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
665 manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
666 if (dev_id != 0x58 || manu_id != 0x4D)
667 return -ENODEV;
668
669 strscpy(info->type, "max6639", I2C_NAME_SIZE);
670
671 return 0;
672}
673
674static void max6639_regulator_disable(void *data)
675{
676 regulator_disable(regulator: data);
677}
678
679static bool max6639_regmap_is_volatile(struct device *dev, unsigned int reg)
680{
681 switch (reg) {
682 case MAX6639_REG_TEMP(0):
683 case MAX6639_REG_TEMP_EXT(0):
684 case MAX6639_REG_TEMP(1):
685 case MAX6639_REG_TEMP_EXT(1):
686 case MAX6639_REG_STATUS:
687 case MAX6639_REG_FAN_CNT(0):
688 case MAX6639_REG_FAN_CNT(1):
689 case MAX6639_REG_TARGTDUTY(0):
690 case MAX6639_REG_TARGTDUTY(1):
691 return true;
692 default:
693 return false;
694 }
695}
696
697static const struct regmap_config max6639_regmap_config = {
698 .reg_bits = 8,
699 .val_bits = 8,
700 .max_register = MAX6639_REG_DEVREV,
701 .cache_type = REGCACHE_MAPLE,
702 .volatile_reg = max6639_regmap_is_volatile,
703};
704
705static int max6639_probe(struct i2c_client *client)
706{
707 struct device *dev = &client->dev;
708 struct max6639_data *data;
709 struct device *hwmon_dev;
710 int err;
711
712 data = devm_kzalloc(dev, size: sizeof(struct max6639_data), GFP_KERNEL);
713 if (!data)
714 return -ENOMEM;
715
716 data->regmap = devm_regmap_init_i2c(client, &max6639_regmap_config);
717 if (IS_ERR(ptr: data->regmap))
718 return dev_err_probe(dev,
719 err: PTR_ERR(ptr: data->regmap),
720 fmt: "regmap initialization failed\n");
721
722 data->reg = devm_regulator_get_optional(dev, id: "fan");
723 if (IS_ERR(ptr: data->reg)) {
724 if (PTR_ERR(ptr: data->reg) != -ENODEV)
725 return PTR_ERR(ptr: data->reg);
726
727 data->reg = NULL;
728 } else {
729 /* Spin up fans */
730 err = regulator_enable(regulator: data->reg);
731 if (err) {
732 dev_err(dev, "Failed to enable fan supply: %d\n", err);
733 return err;
734 }
735 err = devm_add_action_or_reset(dev, max6639_regulator_disable,
736 data->reg);
737 if (err) {
738 dev_err(dev, "Failed to register action: %d\n", err);
739 return err;
740 }
741 }
742
743 /* Initialize the max6639 chip */
744 err = max6639_init_client(client, data);
745 if (err < 0)
746 return err;
747
748 hwmon_dev = devm_hwmon_device_register_with_info(dev, name: client->name,
749 drvdata: data, info: &max6639_chip_info,
750 NULL);
751
752 return PTR_ERR_OR_ZERO(ptr: hwmon_dev);
753}
754
755static int max6639_suspend(struct device *dev)
756{
757 struct max6639_data *data = dev_get_drvdata(dev);
758
759 if (data->reg)
760 regulator_disable(regulator: data->reg);
761
762 return regmap_write_bits(map: data->regmap, MAX6639_REG_GCONFIG, MAX6639_GCONFIG_STANDBY,
763 MAX6639_GCONFIG_STANDBY);
764}
765
766static int max6639_resume(struct device *dev)
767{
768 struct max6639_data *data = dev_get_drvdata(dev);
769 int ret;
770
771 if (data->reg) {
772 ret = regulator_enable(regulator: data->reg);
773 if (ret) {
774 dev_err(dev, "Failed to enable fan supply: %d\n", ret);
775 return ret;
776 }
777 }
778
779 return regmap_write_bits(map: data->regmap, MAX6639_REG_GCONFIG, MAX6639_GCONFIG_STANDBY,
780 val: ~MAX6639_GCONFIG_STANDBY);
781}
782
783static const struct i2c_device_id max6639_id[] = {
784 {"max6639"},
785 { }
786};
787
788MODULE_DEVICE_TABLE(i2c, max6639_id);
789
790static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
791
792static const struct of_device_id max6639_of_match[] = {
793 { .compatible = "maxim,max6639", },
794 { },
795};
796
797static struct i2c_driver max6639_driver = {
798 .class = I2C_CLASS_HWMON,
799 .driver = {
800 .name = "max6639",
801 .pm = pm_sleep_ptr(&max6639_pm_ops),
802 .of_match_table = max6639_of_match,
803 },
804 .probe = max6639_probe,
805 .id_table = max6639_id,
806 .detect = max6639_detect,
807 .address_list = normal_i2c,
808};
809
810module_i2c_driver(max6639_driver);
811
812MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
813MODULE_DESCRIPTION("max6639 driver");
814MODULE_LICENSE("GPL");
815

source code of linux/drivers/hwmon/max6639.c