max6639.c

  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(data->regmap, regs, regvals, 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(data->regmap, MAX6639_REG_TEMP_EXT(channel), &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(data->regmap, MAX6639_REG_THERM_LIMIT(channel), &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(data->regmap, MAX6639_REG_ALERT_LIMIT(channel), &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(data->regmap, MAX6639_REG_OT_LIMIT(channel), &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(data->regmap, MAX6639_REG_STATUS, &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(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(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(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(data->regmap, MAX6639_REG_FAN_CNT(channel), &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, &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(data->regmap, MAX6639_REG_FAN_PPR(channel), --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, 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(data->regmap, MAX6639_REG_TARGTDUTY(channel), &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(data->regmap, regs, regvals, 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(data->regmap, MAX6639_REG_TARGTDUTY(channel),
316				    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(data->regmap, MAX6639_REG_FAN_CONFIG3(channel),
323					 MAX6639_FAN_CONFIG3_FREQ_MASK, i);
324		if (err < 0)
325			return err;
326
327		if (i >> 2)
328			err = regmap_set_bits(data->regmap, MAX6639_REG_GCONFIG,
329					      MAX6639_GCONFIG_PWM_FREQ_HI);
330		else
331			err = regmap_clear_bits(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, val);
360		return res;
361	case hwmon_temp_fault:
362		res = max6639_temp_read_fault(dev, channel, val);
363		return res;
364	case hwmon_temp_max:
365		res = max6639_temp_read_max(dev, channel, val);
366		return res;
367	case hwmon_temp_crit:
368		res = max6639_temp_read_crit(dev, channel, val);
369		return res;
370	case hwmon_temp_emergency:
371		res = max6639_temp_read_emergency(dev, channel, val);
372		return res;
373	case hwmon_temp_max_alarm:
374		res = max6639_get_status(dev, &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);
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);
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, val);
437	case hwmon_pwm:
438		return max6639_read_pwm(dev, attr, channel, 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, attr, channel);
468	case hwmon_pwm:
469		return max6639_pwm_is_visible(data, attr, channel);
470	case hwmon_temp:
471		return max6639_temp_is_visible(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, val;
528	int err;
529
530	err = of_property_read_u32(child, "reg", &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(child, "pulses-per-revolution", &val);
542	if (!err) {
543		if (val < 1 || val > 4) {
544			dev_err(dev, "invalid pulses-per-revolution %u of %pOFn\n", val, child);
545			return -EINVAL;
546		}
547		data->ppr[i] = val;
548	}
549
550	err = of_property_read_u32(child, "max-rpm", &val);
551	if (!err)
552		data->rpm_range[i] = rpm_range_to_reg(val);
553
554	err = of_property_read_u32(child, "target-rpm", &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(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(child);
592			return err;
593		}
594	}
595
596	for (i = 0; i < MAX6639_NUM_CHANNELS; i++) {
597		err = regmap_set_bits(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, i, data->ppr[i]);
603		if (err)
604			return err;
605
606		/* Fans config PWM, RPM */
607		err = regmap_write(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(data->regmap, MAX6639_REG_FAN_CONFIG2a(i), 0x02);
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(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(data->regmap, MAX6639_REG_THERM_LIMIT(i), 80);
628		if (err)
629			return err;
630		err = regmap_write(data->regmap, MAX6639_REG_ALERT_LIMIT(i), 90);
631		if (err)
632			return err;
633		err = regmap_write(data->regmap, MAX6639_REG_OT_LIMIT(i), 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(data->regmap, MAX6639_REG_TARGTDUTY(i), target_duty);
643		if (err)
644			return err;
645	}
646	/* Start monitoring */
647	return regmap_write(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(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(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, 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(data->regmap))
718		return dev_err_probe(dev,
719				     PTR_ERR(data->regmap),
720				     "regmap initialization failed\n");
721
722	data->reg = devm_regulator_get_optional(dev, "fan");
723	if (IS_ERR(data->reg)) {
724		if (PTR_ERR(data->reg) != -ENODEV)
725			return PTR_ERR(data->reg);
726
727		data->reg = NULL;
728	} else {
729		/* Spin up fans */
730		err = regulator_enable(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, client->name,
749							 data, &max6639_chip_info,
750							 NULL);
751
752	return PTR_ERR_OR_ZERO(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(data->reg);
761
762	return regmap_write_bits(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(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(data->regmap, MAX6639_REG_GCONFIG, MAX6639_GCONFIG_STANDBY,
780				 ~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");