summaryrefslogtreecommitdiff
path: root/drivers/hwmon/adt7411.c
blob: c7010b91bc1335330ad054cd250c787236447433 (plain)
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
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
 *
 *  Copyright (C) 2008, 2010 Pengutronix
 *
 *  TODO: SPI, use power-down mode for suspend?, interrupt handling?
 */

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

#define ADT7411_REG_STAT_1			0x00
#define ADT7411_STAT_1_INT_TEMP_HIGH		BIT(0)
#define ADT7411_STAT_1_INT_TEMP_LOW		BIT(1)
#define ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1	BIT(2)
#define ADT7411_STAT_1_EXT_TEMP_LOW		BIT(3)
#define ADT7411_STAT_1_EXT_TEMP_FAULT		BIT(4)
#define ADT7411_STAT_1_AIN2			BIT(5)
#define ADT7411_STAT_1_AIN3			BIT(6)
#define ADT7411_STAT_1_AIN4			BIT(7)
#define ADT7411_REG_STAT_2			0x01
#define ADT7411_STAT_2_AIN5			BIT(0)
#define ADT7411_STAT_2_AIN6			BIT(1)
#define ADT7411_STAT_2_AIN7			BIT(2)
#define ADT7411_STAT_2_AIN8			BIT(3)
#define ADT7411_STAT_2_VDD			BIT(4)
#define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
#define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
#define ADT7411_REG_VDD_MSB			0x06
#define ADT7411_REG_INT_TEMP_MSB		0x07
#define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08

#define ADT7411_REG_CFG1			0x18
#define ADT7411_CFG1_START_MONITOR		BIT(0)
#define ADT7411_CFG1_RESERVED_BIT1		BIT(1)
#define ADT7411_CFG1_EXT_TDM			BIT(2)
#define ADT7411_CFG1_RESERVED_BIT3		BIT(3)

#define ADT7411_REG_CFG2			0x19
#define ADT7411_CFG2_DISABLE_AVG		BIT(5)

#define ADT7411_REG_CFG3			0x1a
#define ADT7411_CFG3_ADC_CLK_225		BIT(0)
#define ADT7411_CFG3_RESERVED_BIT1		BIT(1)
#define ADT7411_CFG3_RESERVED_BIT2		BIT(2)
#define ADT7411_CFG3_RESERVED_BIT3		BIT(3)
#define ADT7411_CFG3_REF_VDD			BIT(4)

#define ADT7411_REG_VDD_HIGH			0x23
#define ADT7411_REG_VDD_LOW			0x24
#define ADT7411_REG_TEMP_HIGH(nr)		(0x25 + 2 * (nr))
#define ADT7411_REG_TEMP_LOW(nr)		(0x26 + 2 * (nr))
#define ADT7411_REG_IN_HIGH(nr)		((nr) > 1 \
						  ? 0x2b + 2 * ((nr)-2) \
						  : 0x27)
#define ADT7411_REG_IN_LOW(nr)			((nr) > 1 \
						  ? 0x2c + 2 * ((nr)-2) \
						  : 0x28)

#define ADT7411_REG_DEVICE_ID			0x4d
#define ADT7411_REG_MANUFACTURER_ID		0x4e

#define ADT7411_DEVICE_ID			0x2
#define ADT7411_MANUFACTURER_ID			0x41

static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };

static const u8 adt7411_in_alarm_reg[] = {
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
};

static const u8 adt7411_in_alarm_bits[] = {
	ADT7411_STAT_2_VDD,
	ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1,
	ADT7411_STAT_1_AIN2,
	ADT7411_STAT_1_AIN3,
	ADT7411_STAT_1_AIN4,
	ADT7411_STAT_2_AIN5,
	ADT7411_STAT_2_AIN6,
	ADT7411_STAT_2_AIN7,
	ADT7411_STAT_2_AIN8,
};

struct adt7411_data {
	struct mutex device_lock;	/* for "atomic" device accesses */
	struct mutex update_lock;
	unsigned long next_update;
	long vref_cached;
	struct i2c_client *client;
	bool use_ext_temp;
};

/*
 * When reading a register containing (up to 4) lsb, all associated
 * msb-registers get locked by the hardware. After _one_ of those msb is read,
 * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
 * is protected here with a mutex, too.
 */
static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
				u8 msb_reg, u8 lsb_shift)
{
	struct adt7411_data *data = i2c_get_clientdata(client);
	int val, tmp;

	mutex_lock(&data->device_lock);

	val = i2c_smbus_read_byte_data(client, lsb_reg);
	if (val < 0)
		goto exit_unlock;

	tmp = (val >> lsb_shift) & 3;
	val = i2c_smbus_read_byte_data(client, msb_reg);

	if (val >= 0)
		val = (val << 2) | tmp;

 exit_unlock:
	mutex_unlock(&data->device_lock);

	return val;
}

static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
				bool flag)
{
	struct adt7411_data *data = i2c_get_clientdata(client);
	int ret, val;

	mutex_lock(&data->device_lock);

	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0)
		goto exit_unlock;

	if (flag)
		val = ret | bit;
	else
		val = ret & ~bit;

	ret = i2c_smbus_write_byte_data(client, reg, val);

 exit_unlock:
	mutex_unlock(&data->device_lock);
	return ret;
}

static ssize_t adt7411_show_bit(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret = i2c_smbus_read_byte_data(client, attr2->index);

	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
}

static ssize_t adt7411_set_bit(struct device *dev,
			       struct device_attribute *attr, const char *buf,
			       size_t count)
{
	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;
	unsigned long flag;

	ret = kstrtoul(buf, 0, &flag);
	if (ret || flag > 1)
		return -EINVAL;

	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);

	/* force update */
	mutex_lock(&data->update_lock);
	data->next_update = jiffies;
	mutex_unlock(&data->update_lock);

	return ret < 0 ? ret : count;
}

#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
	adt7411_set_bit, __bit, __reg)

static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);

static struct attribute *adt7411_attrs[] = {
	&sensor_dev_attr_no_average.dev_attr.attr,
	&sensor_dev_attr_fast_sampling.dev_attr.attr,
	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
	NULL
};
ATTRIBUTE_GROUPS(adt7411);

static int adt7411_read_in_alarm(struct device *dev, int channel, long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	ret = i2c_smbus_read_byte_data(client, adt7411_in_alarm_reg[channel]);
	if (ret < 0)
		return ret;
	*val = !!(ret & adt7411_in_alarm_bits[channel]);
	return 0;
}

static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	switch (attr) {
	case hwmon_in_input:
		ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
					  ADT7411_REG_VDD_MSB, 2);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 1024;
		return 0;
	case hwmon_in_min:
		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_LOW);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 256;
		return 0;
	case hwmon_in_max:
		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_HIGH);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 256;
		return 0;
	case hwmon_in_alarm:
		return adt7411_read_in_alarm(dev, 0, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_update_vref(struct device *dev)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int val;

	if (time_after_eq(jiffies, data->next_update)) {
		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
		if (val < 0)
			return val;

		if (val & ADT7411_CFG3_REF_VDD) {
			val = adt7411_read_in_vdd(dev, hwmon_in_input,
						  &data->vref_cached);
			if (val < 0)
				return val;
		} else {
			data->vref_cached = 2250;
		}

		data->next_update = jiffies + HZ;
	}

	return 0;
}

static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
				long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	int ret;
	int reg, lsb_reg, lsb_shift;
	int nr = channel - 1;

	mutex_lock(&data->update_lock);
	ret = adt7411_update_vref(dev);
	if (ret < 0)
		goto exit_unlock;

	switch (attr) {
	case hwmon_in_input:
		lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
		lsb_shift = 2 * (nr & 0x03);
		ret = adt7411_read_10_bit(client, lsb_reg,
					  ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
					  lsb_shift);
		if (ret < 0)
			goto exit_unlock;
		*val = ret * data->vref_cached / 1024;
		ret = 0;
		break;
	case hwmon_in_min:
	case hwmon_in_max:
		reg = (attr == hwmon_in_min)
			? ADT7411_REG_IN_LOW(channel)
			: ADT7411_REG_IN_HIGH(channel);
		ret = i2c_smbus_read_byte_data(client, reg);
		if (ret < 0)
			goto exit_unlock;
		*val = ret * data->vref_cached / 256;
		ret = 0;
		break;
	case hwmon_in_alarm:
		ret = adt7411_read_in_alarm(dev, channel, val);
		break;
	default:
		ret = -EOPNOTSUPP;
		break;
	}
 exit_unlock:
	mutex_unlock(&data->update_lock);
	return ret;
}

static int adt7411_read_in(struct device *dev, u32 attr, int channel,
			   long *val)
{
	if (channel == 0)
		return adt7411_read_in_vdd(dev, attr, val);
	else
		return adt7411_read_in_chan(dev, attr, channel, val);
}


static int adt7411_read_temp_alarm(struct device *dev, u32 attr, int channel,
				   long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, bit;

	ret = i2c_smbus_read_byte_data(client, ADT7411_REG_STAT_1);
	if (ret < 0)
		return ret;

	switch (attr) {
	case hwmon_temp_min_alarm:
		bit = channel ? ADT7411_STAT_1_EXT_TEMP_LOW
			      : ADT7411_STAT_1_INT_TEMP_LOW;
		break;
	case hwmon_temp_max_alarm:
		bit = channel ? ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1
			      : ADT7411_STAT_1_INT_TEMP_HIGH;
		break;
	case hwmon_temp_fault:
		bit = ADT7411_STAT_1_EXT_TEMP_FAULT;
		break;
	default:
		return -EOPNOTSUPP;
	}

	*val = !!(ret & bit);
	return 0;
}

static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
			     long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, reg, regl, regh;

	switch (attr) {
	case hwmon_temp_input:
		regl = channel ? ADT7411_REG_EXT_TEMP_AIN14_LSB :
				 ADT7411_REG_INT_TEMP_VDD_LSB;
		regh = channel ? ADT7411_REG_EXT_TEMP_AIN1_MSB :
				 ADT7411_REG_INT_TEMP_MSB;
		ret = adt7411_read_10_bit(client, regl, regh, 0);
		if (ret < 0)
			return ret;
		ret = ret & 0x200 ? ret - 0x400 : ret; /* 10 bit signed */
		*val = ret * 250;
		return 0;
	case hwmon_temp_min:
	case hwmon_temp_max:
		reg = (attr == hwmon_temp_min)
			? ADT7411_REG_TEMP_LOW(channel)
			: ADT7411_REG_TEMP_HIGH(channel);
		ret = i2c_smbus_read_byte_data(client, reg);
		if (ret < 0)
			return ret;
		ret = ret & 0x80 ? ret - 0x100 : ret; /* 8 bit signed */
		*val = ret * 1000;
		return 0;
	case hwmon_temp_min_alarm:
	case hwmon_temp_max_alarm:
	case hwmon_temp_fault:
		return adt7411_read_temp_alarm(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_read(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long *val)
{
	switch (type) {
	case hwmon_in:
		return adt7411_read_in(dev, attr, channel, val);
	case hwmon_temp:
		return adt7411_read_temp(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_write_in_vdd(struct device *dev, u32 attr, long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int reg;

	val = clamp_val(val, 0, 255 * 7000 / 256);
	val = DIV_ROUND_CLOSEST(val * 256, 7000);

	switch (attr) {
	case hwmon_in_min:
		reg = ADT7411_REG_VDD_LOW;
		break;
	case hwmon_in_max:
		reg = ADT7411_REG_VDD_HIGH;
		break;
	default:
		return -EOPNOTSUPP;
	}

	return i2c_smbus_write_byte_data(client, reg, val);
}

static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
				 long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, reg;

	mutex_lock(&data->update_lock);
	ret = adt7411_update_vref(dev);
	if (ret < 0)
		goto exit_unlock;
	val = clamp_val(val, 0, 255 * data->vref_cached / 256);
	val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);

	switch (attr) {
	case hwmon_in_min:
		reg = ADT7411_REG_IN_LOW(channel);
		break;
	case hwmon_in_max:
		reg = ADT7411_REG_IN_HIGH(channel);
		break;
	default:
		ret = -EOPNOTSUPP;
		goto exit_unlock;
	}

	ret = i2c_smbus_write_byte_data(client, reg, val);
 exit_unlock:
	mutex_unlock(&data->update_lock);
	return ret;
}

static int adt7411_write_in(struct device *dev, u32 attr, int channel,
			    long val)
{
	if (channel == 0)
		return adt7411_write_in_vdd(dev, attr, val);
	else
		return adt7411_write_in_chan(dev, attr, channel, val);
}

static int adt7411_write_temp(struct device *dev, u32 attr, int channel,
			      long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int reg;

	val = clamp_val(val, -128000, 127000);
	val = DIV_ROUND_CLOSEST(val, 1000);

	switch (attr) {
	case hwmon_temp_min:
		reg = ADT7411_REG_TEMP_LOW(channel);
		break;
	case hwmon_temp_max:
		reg = ADT7411_REG_TEMP_HIGH(channel);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return i2c_smbus_write_byte_data(client, reg, val);
}

static int adt7411_write(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_in:
		return adt7411_write_in(dev, attr, channel, val);
	case hwmon_temp:
		return adt7411_write_temp(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t adt7411_is_visible(const void *_data,
				  enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	const struct adt7411_data *data = _data;
	bool visible;

	switch (type) {
	case hwmon_in:
		visible = channel == 0 || channel >= 3 || !data->use_ext_temp;
		switch (attr) {
		case hwmon_in_input:
		case hwmon_in_alarm:
			return visible ? S_IRUGO : 0;
		case hwmon_in_min:
		case hwmon_in_max:
			return visible ? S_IRUGO | S_IWUSR : 0;
		}
		break;
	case hwmon_temp:
		visible = channel == 0 || data->use_ext_temp;
		switch (attr) {
		case hwmon_temp_input:
		case hwmon_temp_min_alarm:
		case hwmon_temp_max_alarm:
		case hwmon_temp_fault:
			return visible ? S_IRUGO : 0;
		case hwmon_temp_min:
		case hwmon_temp_max:
			return visible ? S_IRUGO | S_IWUSR : 0;
		}
		break;
	default:
		break;
	}
	return 0;
}

static int adt7411_detect(struct i2c_client *client,
			  struct i2c_board_info *info)
{
	int val;

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

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
		dev_dbg(&client->dev,
			"Wrong manufacturer ID. Got %d, expected %d\n",
			val, ADT7411_MANUFACTURER_ID);
		return -ENODEV;
	}

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
	if (val < 0 || val != ADT7411_DEVICE_ID) {
		dev_dbg(&client->dev,
			"Wrong device ID. Got %d, expected %d\n",
			val, ADT7411_DEVICE_ID);
		return -ENODEV;
	}

	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);

	return 0;
}

static int adt7411_init_device(struct adt7411_data *data)
{
	int ret;
	u8 val;

	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG3);
	if (ret < 0)
		return ret;

	/*
	 * We must only write zero to bit 1 and bit 2 and only one to bit 3
	 * according to the datasheet.
	 */
	val = ret;
	val &= ~(ADT7411_CFG3_RESERVED_BIT1 | ADT7411_CFG3_RESERVED_BIT2);
	val |= ADT7411_CFG3_RESERVED_BIT3;

	ret = i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG3, val);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG1);
	if (ret < 0)
		return ret;

	data->use_ext_temp = ret & ADT7411_CFG1_EXT_TDM;

	/*
	 * We must only write zero to bit 1 and only one to bit 3 according to
	 * the datasheet.
	 */
	val = ret;
	val &= ~ADT7411_CFG1_RESERVED_BIT1;
	val |= ADT7411_CFG1_RESERVED_BIT3;

	/* enable monitoring */
	val |= ADT7411_CFG1_START_MONITOR;

	return i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG1, val);
}

static const struct hwmon_channel_info *adt7411_info[] = {
	HWMON_CHANNEL_INFO(in,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
			   HWMON_T_MAX | HWMON_T_MAX_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
			   HWMON_T_MAX | HWMON_T_MAX_ALARM | HWMON_T_FAULT),
	NULL
};

static const struct hwmon_ops adt7411_hwmon_ops = {
	.is_visible = adt7411_is_visible,
	.read = adt7411_read,
	.write = adt7411_write,
};

static const struct hwmon_chip_info adt7411_chip_info = {
	.ops = &adt7411_hwmon_ops,
	.info = adt7411_info,
};

static int adt7411_probe(struct i2c_client *client,
				   const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct adt7411_data *data;
	struct device *hwmon_dev;
	int ret;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	ret = adt7411_init_device(data);
	if (ret < 0)
		return ret;

	/* force update on first occasion */
	data->next_update = jiffies;

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data,
							 &adt7411_chip_info,
							 adt7411_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id adt7411_id[] = {
	{ "adt7411", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, adt7411_id);

static struct i2c_driver adt7411_driver = {
	.driver		= {
		.name		= "adt7411",
	},
	.probe  = adt7411_probe,
	.id_table = adt7411_id,
	.detect = adt7411_detect,
	.address_list = normal_i2c,
	.class = I2C_CLASS_HWMON,
};

module_i2c_driver(adt7411_driver);

MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
	"Wolfram Sang <w.sang@pengutronix.de>");
MODULE_DESCRIPTION("ADT7411 driver");
MODULE_LICENSE("GPL v2");