summaryrefslogtreecommitdiff
path: root/drivers/hwmon/max6639.c
blob: 6e60036abfa724a8ea4773faf9f2dab18c902fce (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
/*
 * max6639.c - Support for Maxim MAX6639
 *
 * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
 *
 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
 *
 * based on the initial MAX6639 support from semptian.net
 * by He Changqing <hechangqing@semptian.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/i2c/max6639.h>

/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };

/* The MAX6639 registers, valid channel numbers: 0, 1 */
#define MAX6639_REG_TEMP(ch)			(0x00 + (ch))
#define MAX6639_REG_STATUS			0x02
#define MAX6639_REG_OUTPUT_MASK			0x03
#define MAX6639_REG_GCONFIG			0x04
#define MAX6639_REG_TEMP_EXT(ch)		(0x05 + (ch))
#define MAX6639_REG_ALERT_LIMIT(ch)		(0x08 + (ch))
#define MAX6639_REG_OT_LIMIT(ch)		(0x0A + (ch))
#define MAX6639_REG_THERM_LIMIT(ch)		(0x0C + (ch))
#define MAX6639_REG_FAN_CONFIG1(ch)		(0x10 + (ch) * 4)
#define MAX6639_REG_FAN_CONFIG2a(ch)		(0x11 + (ch) * 4)
#define MAX6639_REG_FAN_CONFIG2b(ch)		(0x12 + (ch) * 4)
#define MAX6639_REG_FAN_CONFIG3(ch)		(0x13 + (ch) * 4)
#define MAX6639_REG_FAN_CNT(ch)			(0x20 + (ch))
#define MAX6639_REG_TARGET_CNT(ch)		(0x22 + (ch))
#define MAX6639_REG_FAN_PPR(ch)			(0x24 + (ch))
#define MAX6639_REG_TARGTDUTY(ch)		(0x26 + (ch))
#define MAX6639_REG_FAN_START_TEMP(ch)		(0x28 + (ch))
#define MAX6639_REG_DEVID			0x3D
#define MAX6639_REG_MANUID			0x3E
#define MAX6639_REG_DEVREV			0x3F

/* Register bits */
#define MAX6639_GCONFIG_STANDBY			0x80
#define MAX6639_GCONFIG_POR			0x40
#define MAX6639_GCONFIG_DISABLE_TIMEOUT		0x20
#define MAX6639_GCONFIG_CH2_LOCAL		0x10
#define MAX6639_GCONFIG_PWM_FREQ_HI		0x08

#define MAX6639_FAN_CONFIG1_PWM			0x80

#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40

static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };

#define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
				0 : (rpm_ranges[rpm_range] * 30) / (val))
#define TEMP_LIMIT_TO_REG(val)	SENSORS_LIMIT((val) / 1000, 0, 255)

/*
 * Client data (each client gets its own)
 */
struct max6639_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	/* Register values sampled regularly */
	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
	bool temp_fault[2];	/* Detected temperature diode failure */
	u8 fan[2];		/* Register value: TACH count for fans >=30 */
	u8 status;		/* Detected channel alarms and fan failures */

	/* Register values only written to */
	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */

	/* Register values initialized only once */
	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
	u8 rpm_range;		/* Index in above rpm_ranges table */
};

static struct max6639_data *max6639_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct max6639_data *ret = data;
	int i;
	int status_reg;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
		int res;

		dev_dbg(&client->dev, "Starting max6639 update\n");

		status_reg = i2c_smbus_read_byte_data(client,
						      MAX6639_REG_STATUS);
		if (status_reg < 0) {
			ret = ERR_PTR(status_reg);
			goto abort;
		}

		data->status = status_reg;

		for (i = 0; i < 2; i++) {
			res = i2c_smbus_read_byte_data(client,
					MAX6639_REG_FAN_CNT(i));
			if (res < 0) {
				ret = ERR_PTR(res);
				goto abort;
			}
			data->fan[i] = res;

			res = i2c_smbus_read_byte_data(client,
					MAX6639_REG_TEMP_EXT(i));
			if (res < 0) {
				ret = ERR_PTR(res);
				goto abort;
			}
			data->temp[i] = res >> 5;
			data->temp_fault[i] = res & 0x01;

			res = i2c_smbus_read_byte_data(client,
					MAX6639_REG_TEMP(i));
			if (res < 0) {
				ret = ERR_PTR(res);
				goto abort;
			}
			data->temp[i] |= res << 3;
		}

		data->last_updated = jiffies;
		data->valid = 1;
	}
abort:
	mutex_unlock(&data->update_lock);

	return ret;
}

static ssize_t show_temp_input(struct device *dev,
			       struct device_attribute *dev_attr, char *buf)
{
	long temp;
	struct max6639_data *data = max6639_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	if (IS_ERR(data))
		return PTR_ERR(data);

	temp = data->temp[attr->index] * 125;
	return sprintf(buf, "%ld\n", temp);
}

static ssize_t show_temp_fault(struct device *dev,
			       struct device_attribute *dev_attr, char *buf)
{
	struct max6639_data *data = max6639_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
}

static ssize_t show_temp_max(struct device *dev,
			     struct device_attribute *dev_attr, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
}

static ssize_t set_temp_max(struct device *dev,
			    struct device_attribute *dev_attr,
			    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
	unsigned long val;
	int res;

	res = kstrtoul(buf, 10, &val);
	if (res)
		return res;

	mutex_lock(&data->update_lock);
	data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
	i2c_smbus_write_byte_data(client,
				  MAX6639_REG_THERM_LIMIT(attr->index),
				  data->temp_therm[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temp_crit(struct device *dev,
			      struct device_attribute *dev_attr, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
}

static ssize_t set_temp_crit(struct device *dev,
			     struct device_attribute *dev_attr,
			     const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
	unsigned long val;
	int res;

	res = kstrtoul(buf, 10, &val);
	if (res)
		return res;

	mutex_lock(&data->update_lock);
	data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
	i2c_smbus_write_byte_data(client,
				  MAX6639_REG_ALERT_LIMIT(attr->index),
				  data->temp_alert[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_temp_emergency(struct device *dev,
				   struct device_attribute *dev_attr,
				   char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
}

static ssize_t set_temp_emergency(struct device *dev,
				  struct device_attribute *dev_attr,
				  const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
	unsigned long val;
	int res;

	res = kstrtoul(buf, 10, &val);
	if (res)
		return res;

	mutex_lock(&data->update_lock);
	data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
	i2c_smbus_write_byte_data(client,
				  MAX6639_REG_OT_LIMIT(attr->index),
				  data->temp_ot[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_pwm(struct device *dev,
			struct device_attribute *dev_attr, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
}

static ssize_t set_pwm(struct device *dev,
		       struct device_attribute *dev_attr,
		       const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max6639_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
	unsigned long val;
	int res;

	res = kstrtoul(buf, 10, &val);
	if (res)
		return res;

	val = SENSORS_LIMIT(val, 0, 255);

	mutex_lock(&data->update_lock);
	data->pwm[attr->index] = (u8)(val * 120 / 255);
	i2c_smbus_write_byte_data(client,
				  MAX6639_REG_TARGTDUTY(attr->index),
				  data->pwm[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_fan_input(struct device *dev,
			      struct device_attribute *dev_attr, char *buf)
{
	struct max6639_data *data = max6639_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
		       data->rpm_range));
}

static ssize_t show_alarm(struct device *dev,
			  struct device_attribute *dev_attr, char *buf)
{
	struct max6639_data *data = max6639_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input, NULL, 1);
static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
		set_temp_max, 0);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
		set_temp_max, 1);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit,
		set_temp_crit, 0);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit,
		set_temp_crit, 1);
static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO,
		show_temp_emergency, set_temp_emergency, 0);
static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO,
		show_temp_emergency, set_temp_emergency, 1);
static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 0);
static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(fan2_fault, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 7);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 6);
static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 5);
static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 4);


static struct attribute *max6639_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp1_fault.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_pwm2.dev_attr.attr,
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan1_fault.dev_attr.attr,
	&sensor_dev_attr_fan2_fault.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group max6639_group = {
	.attrs = max6639_attributes,
};

/*
 *  returns respective index in rpm_ranges table
 *  1 by default on invalid range
 */
static int rpm_range_to_reg(int range)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
		if (rpm_ranges[i] == range)
			return i;
	}

	return 1; /* default: 4000 RPM */
}

static int max6639_init_client(struct i2c_client *client)
{
	struct max6639_data *data = i2c_get_clientdata(client);
	struct max6639_platform_data *max6639_info =
		client->dev.platform_data;
	int i;
	int rpm_range = 1; /* default: 4000 RPM */
	int err;

	/* Reset chip to default values, see below for GCONFIG setup */
	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
				  MAX6639_GCONFIG_POR);
	if (err)
		goto exit;

	/* Fans pulse per revolution is 2 by default */
	if (max6639_info && max6639_info->ppr > 0 &&
			max6639_info->ppr < 5)
		data->ppr = max6639_info->ppr;
	else
		data->ppr = 2;
	data->ppr -= 1;

	if (max6639_info)
		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
	data->rpm_range = rpm_range;

	for (i = 0; i < 2; i++) {

		/* Set Fan pulse per revolution */
		err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_FAN_PPR(i),
				data->ppr << 6);
		if (err)
			goto exit;

		/* Fans config PWM, RPM */
		err = i2c_smbus_write_byte_data(client,
			MAX6639_REG_FAN_CONFIG1(i),
			MAX6639_FAN_CONFIG1_PWM | rpm_range);
		if (err)
			goto exit;

		/* Fans PWM polarity high by default */
		if (max6639_info && max6639_info->pwm_polarity == 0)
			err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
		else
			err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
		if (err)
			goto exit;

		/*
		 * /THERM full speed enable,
		 * PWM frequency 25kHz, see also GCONFIG below
		 */
		err = i2c_smbus_write_byte_data(client,
			MAX6639_REG_FAN_CONFIG3(i),
			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
		if (err)
			goto exit;

		/* Max. temp. 80C/90C/100C */
		data->temp_therm[i] = 80;
		data->temp_alert[i] = 90;
		data->temp_ot[i] = 100;
		err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_THERM_LIMIT(i),
				data->temp_therm[i]);
		if (err)
			goto exit;
		err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_ALERT_LIMIT(i),
				data->temp_alert[i]);
		if (err)
			goto exit;
		err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
		if (err)
			goto exit;

		/* PWM 120/120 (i.e. 100%) */
		data->pwm[i] = 120;
		err = i2c_smbus_write_byte_data(client,
				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
		if (err)
			goto exit;
	}
	/* Start monitoring */
	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
		MAX6639_GCONFIG_PWM_FREQ_HI);
exit:
	return err;
}

/* Return 0 if detection is successful, -ENODEV otherwise */
static int max6639_detect(struct i2c_client *client,
			  struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int dev_id, manu_id;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -ENODEV;

	/* Actual detection via device and manufacturer ID */
	dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
	manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
	if (dev_id != 0x58 || manu_id != 0x4D)
		return -ENODEV;

	strlcpy(info->type, "max6639", I2C_NAME_SIZE);

	return 0;
}

static int max6639_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct max6639_data *data;
	int err;

	data = devm_kzalloc(&client->dev, sizeof(struct max6639_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* Initialize the max6639 chip */
	err = max6639_init_client(client);
	if (err < 0)
		return err;

	/* Register sysfs hooks */
	err = sysfs_create_group(&client->dev.kobj, &max6639_group);
	if (err)
		return err;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto error_remove;
	}

	dev_info(&client->dev, "temperature sensor and fan control found\n");

	return 0;

error_remove:
	sysfs_remove_group(&client->dev.kobj, &max6639_group);
	return err;
}

static int max6639_remove(struct i2c_client *client)
{
	struct max6639_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &max6639_group);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int max6639_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
	if (data < 0)
		return data;

	return i2c_smbus_write_byte_data(client,
			MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
}

static int max6639_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
	if (data < 0)
		return data;

	return i2c_smbus_write_byte_data(client,
			MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
}
#endif /* CONFIG_PM_SLEEP */

static const struct i2c_device_id max6639_id[] = {
	{"max6639", 0},
	{ }
};

MODULE_DEVICE_TABLE(i2c, max6639_id);

static const struct dev_pm_ops max6639_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(max6639_suspend, max6639_resume)
};

static struct i2c_driver max6639_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
		   .name = "max6639",
		   .pm = &max6639_pm_ops,
		   },
	.probe = max6639_probe,
	.remove = max6639_remove,
	.id_table = max6639_id,
	.detect = max6639_detect,
	.address_list = normal_i2c,
};

module_i2c_driver(max6639_driver);

MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("max6639 driver");
MODULE_LICENSE("GPL");