summaryrefslogtreecommitdiff
path: root/drivers/hwmon/amc6821.c
blob: fcb18535fd56a277ce1337597498ce3be34048d9 (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
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
/*
 * amc6821.c - Part of lm_sensors, Linux kernel modules for hardware
 *	       monitoring
 * Copyright (C) 2009 T. Mertelj <tomaz.mertelj@guest.arnes.si>
 *
 * Based on max6650.c:
 * Copyright (C) 2007 Hans J. Koch <hjk@hansjkoch.de>
 *
 * 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/kernel.h>	/* Needed for KERN_INFO */
#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>


/*
 * Addresses to scan.
 */

static const unsigned short normal_i2c[] = {0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e,
	0x4c, 0x4d, 0x4e, I2C_CLIENT_END};



/*
 * Insmod parameters
 */

static int pwminv;	/*Inverted PWM output. */
module_param(pwminv, int, S_IRUGO);

static int init = 1; /*Power-on initialization.*/
module_param(init, int, S_IRUGO);


enum chips { amc6821 };

#define AMC6821_REG_DEV_ID 0x3D
#define AMC6821_REG_COMP_ID 0x3E
#define AMC6821_REG_CONF1 0x00
#define AMC6821_REG_CONF2 0x01
#define AMC6821_REG_CONF3 0x3F
#define AMC6821_REG_CONF4 0x04
#define AMC6821_REG_STAT1 0x02
#define AMC6821_REG_STAT2 0x03
#define AMC6821_REG_TDATA_LOW 0x08
#define AMC6821_REG_TDATA_HI 0x09
#define AMC6821_REG_LTEMP_HI 0x0A
#define AMC6821_REG_RTEMP_HI 0x0B
#define AMC6821_REG_LTEMP_LIMIT_MIN 0x15
#define AMC6821_REG_LTEMP_LIMIT_MAX 0x14
#define AMC6821_REG_RTEMP_LIMIT_MIN 0x19
#define AMC6821_REG_RTEMP_LIMIT_MAX 0x18
#define AMC6821_REG_LTEMP_CRIT 0x1B
#define AMC6821_REG_RTEMP_CRIT 0x1D
#define AMC6821_REG_PSV_TEMP 0x1C
#define AMC6821_REG_DCY 0x22
#define AMC6821_REG_LTEMP_FAN_CTRL 0x24
#define AMC6821_REG_RTEMP_FAN_CTRL 0x25
#define AMC6821_REG_DCY_LOW_TEMP 0x21

#define AMC6821_REG_TACH_LLIMITL 0x10
#define AMC6821_REG_TACH_LLIMITH 0x11
#define AMC6821_REG_TACH_HLIMITL 0x12
#define AMC6821_REG_TACH_HLIMITH 0x13

#define AMC6821_CONF1_START 0x01
#define AMC6821_CONF1_FAN_INT_EN 0x02
#define AMC6821_CONF1_FANIE 0x04
#define AMC6821_CONF1_PWMINV 0x08
#define AMC6821_CONF1_FAN_FAULT_EN 0x10
#define AMC6821_CONF1_FDRC0 0x20
#define AMC6821_CONF1_FDRC1 0x40
#define AMC6821_CONF1_THERMOVIE 0x80

#define AMC6821_CONF2_PWM_EN 0x01
#define AMC6821_CONF2_TACH_MODE 0x02
#define AMC6821_CONF2_TACH_EN 0x04
#define AMC6821_CONF2_RTFIE 0x08
#define AMC6821_CONF2_LTOIE 0x10
#define AMC6821_CONF2_RTOIE 0x20
#define AMC6821_CONF2_PSVIE 0x40
#define AMC6821_CONF2_RST 0x80

#define AMC6821_CONF3_THERM_FAN_EN 0x80
#define AMC6821_CONF3_REV_MASK 0x0F

#define AMC6821_CONF4_OVREN 0x10
#define AMC6821_CONF4_TACH_FAST 0x20
#define AMC6821_CONF4_PSPR 0x40
#define AMC6821_CONF4_MODE 0x80

#define AMC6821_STAT1_RPM_ALARM 0x01
#define AMC6821_STAT1_FANS 0x02
#define AMC6821_STAT1_RTH 0x04
#define AMC6821_STAT1_RTL 0x08
#define AMC6821_STAT1_R_THERM 0x10
#define AMC6821_STAT1_RTF 0x20
#define AMC6821_STAT1_LTH 0x40
#define AMC6821_STAT1_LTL 0x80

#define AMC6821_STAT2_RTC 0x08
#define AMC6821_STAT2_LTC 0x10
#define AMC6821_STAT2_LPSV 0x20
#define AMC6821_STAT2_L_THERM 0x40
#define AMC6821_STAT2_THERM_IN 0x80

enum {IDX_TEMP1_INPUT = 0, IDX_TEMP1_MIN, IDX_TEMP1_MAX,
	IDX_TEMP1_CRIT, IDX_TEMP2_INPUT, IDX_TEMP2_MIN,
	IDX_TEMP2_MAX, IDX_TEMP2_CRIT,
	TEMP_IDX_LEN, };

static const u8 temp_reg[] = {AMC6821_REG_LTEMP_HI,
			AMC6821_REG_LTEMP_LIMIT_MIN,
			AMC6821_REG_LTEMP_LIMIT_MAX,
			AMC6821_REG_LTEMP_CRIT,
			AMC6821_REG_RTEMP_HI,
			AMC6821_REG_RTEMP_LIMIT_MIN,
			AMC6821_REG_RTEMP_LIMIT_MAX,
			AMC6821_REG_RTEMP_CRIT, };

enum {IDX_FAN1_INPUT = 0, IDX_FAN1_MIN, IDX_FAN1_MAX,
	FAN1_IDX_LEN, };

static const u8 fan_reg_low[] = {AMC6821_REG_TDATA_LOW,
			AMC6821_REG_TACH_LLIMITL,
			AMC6821_REG_TACH_HLIMITL, };


static const u8 fan_reg_hi[] = {AMC6821_REG_TDATA_HI,
			AMC6821_REG_TACH_LLIMITH,
			AMC6821_REG_TACH_HLIMITH, };

static int amc6821_probe(
		struct i2c_client *client,
		const struct i2c_device_id *id);
static int amc6821_detect(
		struct i2c_client *client,
		struct i2c_board_info *info);
static int amc6821_init_client(struct i2c_client *client);
static int amc6821_remove(struct i2c_client *client);
static struct amc6821_data *amc6821_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id amc6821_id[] = {
	{ "amc6821", amc6821 },
	{ }
};

MODULE_DEVICE_TABLE(i2c, amc6821_id);

static struct i2c_driver amc6821_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
		.name	= "amc6821",
	},
	.probe = amc6821_probe,
	.remove = amc6821_remove,
	.id_table = amc6821_id,
	.detect = amc6821_detect,
	.address_list = normal_i2c,
};


/*
 * Client data (each client gets its own)
 */

struct amc6821_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* register values */
	int temp[TEMP_IDX_LEN];

	u16 fan[FAN1_IDX_LEN];
	u8 fan1_div;

	u8 pwm1;
	u8 temp1_auto_point_temp[3];
	u8 temp2_auto_point_temp[3];
	u8 pwm1_auto_point_pwm[3];
	u8 pwm1_enable;
	u8 pwm1_auto_channels_temp;

	u8 stat1;
	u8 stat2;
};


static ssize_t get_temp(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	int ix = to_sensor_dev_attr(devattr)->index;

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



static ssize_t set_temp(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf,
		size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	int ix = to_sensor_dev_attr(attr)->index;
	long val;

	int ret = kstrtol(buf, 10, &val);
	if (ret)
		return ret;
	val = clamp_val(val / 1000, -128, 127);

	mutex_lock(&data->update_lock);
	data->temp[ix] = val;
	if (i2c_smbus_write_byte_data(client, temp_reg[ix], data->temp[ix])) {
		dev_err(&client->dev, "Register write error, aborting.\n");
		count = -EIO;
	}
	mutex_unlock(&data->update_lock);
	return count;
}




static ssize_t get_temp_alarm(
	struct device *dev,
	struct device_attribute *devattr,
	char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	int ix = to_sensor_dev_attr(devattr)->index;
	u8 flag;

	switch (ix) {
	case IDX_TEMP1_MIN:
		flag = data->stat1 & AMC6821_STAT1_LTL;
		break;
	case IDX_TEMP1_MAX:
		flag = data->stat1 & AMC6821_STAT1_LTH;
		break;
	case IDX_TEMP1_CRIT:
		flag = data->stat2 & AMC6821_STAT2_LTC;
		break;
	case IDX_TEMP2_MIN:
		flag = data->stat1 & AMC6821_STAT1_RTL;
		break;
	case IDX_TEMP2_MAX:
		flag = data->stat1 & AMC6821_STAT1_RTH;
		break;
	case IDX_TEMP2_CRIT:
		flag = data->stat2 & AMC6821_STAT2_RTC;
		break;
	default:
		dev_dbg(dev, "Unknown attr->index (%d).\n", ix);
		return -EINVAL;
	}
	if (flag)
		return sprintf(buf, "1");
	else
		return sprintf(buf, "0");
}




static ssize_t get_temp2_fault(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	if (data->stat1 & AMC6821_STAT1_RTF)
		return sprintf(buf, "1");
	else
		return sprintf(buf, "0");
}

static ssize_t get_pwm1(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	return sprintf(buf, "%d\n", data->pwm1);
}

static ssize_t set_pwm1(
		struct device *dev,
		struct device_attribute *devattr,
		const char *buf,
		size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	long val;
	int ret = kstrtol(buf, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&data->update_lock);
	data->pwm1 = clamp_val(val , 0, 255);
	i2c_smbus_write_byte_data(client, AMC6821_REG_DCY, data->pwm1);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t get_pwm1_enable(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	return sprintf(buf, "%d\n", data->pwm1_enable);
}

static ssize_t set_pwm1_enable(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf,
		size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	long val;
	int config = kstrtol(buf, 10, &val);
	if (config)
		return config;

	config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
	if (config < 0) {
			dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
			return config;
	}

	switch (val) {
	case 1:
		config &= ~AMC6821_CONF1_FDRC0;
		config &= ~AMC6821_CONF1_FDRC1;
		break;
	case 2:
		config &= ~AMC6821_CONF1_FDRC0;
		config |= AMC6821_CONF1_FDRC1;
		break;
	case 3:
		config |= AMC6821_CONF1_FDRC0;
		config |= AMC6821_CONF1_FDRC1;
		break;
	default:
		return -EINVAL;
	}
	mutex_lock(&data->update_lock);
	if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF1, config)) {
			dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
			count = -EIO;
	}
	mutex_unlock(&data->update_lock);
	return count;
}


static ssize_t get_pwm1_auto_channels_temp(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	return sprintf(buf, "%d\n", data->pwm1_auto_channels_temp);
}


static ssize_t get_temp_auto_point_temp(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	int ix = to_sensor_dev_attr_2(devattr)->index;
	int nr = to_sensor_dev_attr_2(devattr)->nr;
	struct amc6821_data *data = amc6821_update_device(dev);
	switch (nr) {
	case 1:
		return sprintf(buf, "%d\n",
			data->temp1_auto_point_temp[ix] * 1000);
		break;
	case 2:
		return sprintf(buf, "%d\n",
			data->temp2_auto_point_temp[ix] * 1000);
		break;
	default:
		dev_dbg(dev, "Unknown attr->nr (%d).\n", nr);
		return -EINVAL;
	}
}


static ssize_t get_pwm1_auto_point_pwm(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	int ix = to_sensor_dev_attr(devattr)->index;
	struct amc6821_data *data = amc6821_update_device(dev);
	return sprintf(buf, "%d\n", data->pwm1_auto_point_pwm[ix]);
}


static inline ssize_t set_slope_register(struct i2c_client *client,
		u8 reg,
		u8 dpwm,
		u8 *ptemp)
{
	int dt;
	u8 tmp;

	dt = ptemp[2]-ptemp[1];
	for (tmp = 4; tmp > 0; tmp--) {
		if (dt * (0x20 >> tmp) >= dpwm)
			break;
	}
	tmp |= (ptemp[1] & 0x7C) << 1;
	if (i2c_smbus_write_byte_data(client,
			reg, tmp)) {
		dev_err(&client->dev, "Register write error, aborting.\n");
		return -EIO;
	}
	return 0;
}



static ssize_t set_temp_auto_point_temp(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf,
		size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = amc6821_update_device(dev);
	int ix = to_sensor_dev_attr_2(attr)->index;
	int nr = to_sensor_dev_attr_2(attr)->nr;
	u8 *ptemp;
	u8 reg;
	int dpwm;
	long val;
	int ret = kstrtol(buf, 10, &val);
	if (ret)
		return ret;

	switch (nr) {
	case 1:
		ptemp = data->temp1_auto_point_temp;
		reg = AMC6821_REG_LTEMP_FAN_CTRL;
		break;
	case 2:
		ptemp = data->temp2_auto_point_temp;
		reg = AMC6821_REG_RTEMP_FAN_CTRL;
		break;
	default:
		dev_dbg(dev, "Unknown attr->nr (%d).\n", nr);
		return -EINVAL;
	}

	data->valid = 0;
	mutex_lock(&data->update_lock);
	switch (ix) {
	case 0:
		ptemp[0] = clamp_val(val / 1000, 0,
				     data->temp1_auto_point_temp[1]);
		ptemp[0] = clamp_val(ptemp[0], 0,
				     data->temp2_auto_point_temp[1]);
		ptemp[0] = clamp_val(ptemp[0], 0, 63);
		if (i2c_smbus_write_byte_data(
					client,
					AMC6821_REG_PSV_TEMP,
					ptemp[0])) {
				dev_err(&client->dev,
					"Register write error, aborting.\n");
				count = -EIO;
		}
		goto EXIT;
		break;
	case 1:
		ptemp[1] = clamp_val(val / 1000, (ptemp[0] & 0x7C) + 4, 124);
		ptemp[1] &= 0x7C;
		ptemp[2] = clamp_val(ptemp[2], ptemp[1] + 1, 255);
		break;
	case 2:
		ptemp[2] = clamp_val(val / 1000, ptemp[1]+1, 255);
		break;
	default:
		dev_dbg(dev, "Unknown attr->index (%d).\n", ix);
		count = -EINVAL;
		goto EXIT;
	}
	dpwm = data->pwm1_auto_point_pwm[2] - data->pwm1_auto_point_pwm[1];
	if (set_slope_register(client, reg, dpwm, ptemp))
		count = -EIO;

EXIT:
	mutex_unlock(&data->update_lock);
	return count;
}



static ssize_t set_pwm1_auto_point_pwm(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf,
		size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	int dpwm;
	long val;
	int ret = kstrtol(buf, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&data->update_lock);
	data->pwm1_auto_point_pwm[1] = clamp_val(val, 0, 254);
	if (i2c_smbus_write_byte_data(client, AMC6821_REG_DCY_LOW_TEMP,
			data->pwm1_auto_point_pwm[1])) {
		dev_err(&client->dev, "Register write error, aborting.\n");
		count = -EIO;
		goto EXIT;
	}
	dpwm = data->pwm1_auto_point_pwm[2] - data->pwm1_auto_point_pwm[1];
	if (set_slope_register(client, AMC6821_REG_LTEMP_FAN_CTRL, dpwm,
			data->temp1_auto_point_temp)) {
		count = -EIO;
		goto EXIT;
	}
	if (set_slope_register(client, AMC6821_REG_RTEMP_FAN_CTRL, dpwm,
			data->temp2_auto_point_temp)) {
		count = -EIO;
		goto EXIT;
	}

EXIT:
	data->valid = 0;
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t get_fan(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	int ix = to_sensor_dev_attr(devattr)->index;
	if (0 == data->fan[ix])
		return sprintf(buf, "0");
	return sprintf(buf, "%d\n", (int)(6000000 / data->fan[ix]));
}



static ssize_t get_fan1_fault(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	if (data->stat1 & AMC6821_STAT1_FANS)
		return sprintf(buf, "1");
	else
		return sprintf(buf, "0");
}



static ssize_t set_fan(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	long val;
	int ix = to_sensor_dev_attr(attr)->index;
	int ret = kstrtol(buf, 10, &val);
	if (ret)
		return ret;
	val = 1 > val ? 0xFFFF : 6000000/val;

	mutex_lock(&data->update_lock);
	data->fan[ix] = (u16) clamp_val(val, 1, 0xFFFF);
	if (i2c_smbus_write_byte_data(client, fan_reg_low[ix],
			data->fan[ix] & 0xFF)) {
		dev_err(&client->dev, "Register write error, aborting.\n");
		count = -EIO;
		goto EXIT;
	}
	if (i2c_smbus_write_byte_data(client,
			fan_reg_hi[ix], data->fan[ix] >> 8)) {
		dev_err(&client->dev, "Register write error, aborting.\n");
		count = -EIO;
	}
EXIT:
	mutex_unlock(&data->update_lock);
	return count;
}



static ssize_t get_fan1_div(
		struct device *dev,
		struct device_attribute *devattr,
		char *buf)
{
	struct amc6821_data *data = amc6821_update_device(dev);
	return sprintf(buf, "%d\n", data->fan1_div);
}

static ssize_t set_fan1_div(
		struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	long val;
	int config = kstrtol(buf, 10, &val);
	if (config)
		return config;

	config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF4);
	if (config < 0) {
		dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
		return config;
	}
	mutex_lock(&data->update_lock);
	switch (val) {
	case 2:
		config &= ~AMC6821_CONF4_PSPR;
		data->fan1_div = 2;
		break;
	case 4:
		config |= AMC6821_CONF4_PSPR;
		data->fan1_div = 4;
		break;
	default:
		count = -EINVAL;
		goto EXIT;
	}
	if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF4, config)) {
		dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
		count = -EIO;
	}
EXIT:
	mutex_unlock(&data->update_lock);
	return count;
}



static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
	get_temp, NULL, IDX_TEMP1_INPUT);
static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP1_MIN);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP1_MAX);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP1_CRIT);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP1_MIN);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP1_MAX);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP1_CRIT);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO | S_IWUSR,
	get_temp, NULL, IDX_TEMP2_INPUT);
static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP2_MIN);
static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP2_MAX);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR, get_temp,
	set_temp, IDX_TEMP2_CRIT);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO,
	get_temp2_fault, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP2_MIN);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP2_MAX);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO,
	get_temp_alarm, NULL, IDX_TEMP2_CRIT);
static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, IDX_FAN1_INPUT);
static SENSOR_DEVICE_ATTR(fan1_min, S_IRUGO | S_IWUSR,
	get_fan, set_fan, IDX_FAN1_MIN);
static SENSOR_DEVICE_ATTR(fan1_max, S_IRUGO | S_IWUSR,
	get_fan, set_fan, IDX_FAN1_MAX);
static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan1_fault, NULL, 0);
static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
	get_fan1_div, set_fan1_div, 0);

static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm1, set_pwm1, 0);
static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
	get_pwm1_enable, set_pwm1_enable, 0);
static SENSOR_DEVICE_ATTR(pwm1_auto_point1_pwm, S_IRUGO,
	get_pwm1_auto_point_pwm, NULL, 0);
static SENSOR_DEVICE_ATTR(pwm1_auto_point2_pwm, S_IWUSR | S_IRUGO,
	get_pwm1_auto_point_pwm, set_pwm1_auto_point_pwm, 1);
static SENSOR_DEVICE_ATTR(pwm1_auto_point3_pwm, S_IRUGO,
	get_pwm1_auto_point_pwm, NULL, 2);
static SENSOR_DEVICE_ATTR(pwm1_auto_channels_temp, S_IRUGO,
	get_pwm1_auto_channels_temp, NULL, 0);
static SENSOR_DEVICE_ATTR_2(temp1_auto_point1_temp, S_IRUGO,
	get_temp_auto_point_temp, NULL, 1, 0);
static SENSOR_DEVICE_ATTR_2(temp1_auto_point2_temp, S_IWUSR | S_IRUGO,
	get_temp_auto_point_temp, set_temp_auto_point_temp, 1, 1);
static SENSOR_DEVICE_ATTR_2(temp1_auto_point3_temp, S_IWUSR | S_IRUGO,
	get_temp_auto_point_temp, set_temp_auto_point_temp, 1, 2);

static SENSOR_DEVICE_ATTR_2(temp2_auto_point1_temp, S_IWUSR | S_IRUGO,
	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 0);
static SENSOR_DEVICE_ATTR_2(temp2_auto_point2_temp, S_IWUSR | S_IRUGO,
	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 1);
static SENSOR_DEVICE_ATTR_2(temp2_auto_point3_temp, S_IWUSR | S_IRUGO,
	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 2);



static struct attribute *amc6821_attrs[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan1_min.dev_attr.attr,
	&sensor_dev_attr_fan1_max.dev_attr.attr,
	&sensor_dev_attr_fan1_fault.dev_attr.attr,
	&sensor_dev_attr_fan1_div.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_temp1_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_temp1_auto_point3_temp.dev_attr.attr,
	&sensor_dev_attr_temp2_auto_point1_temp.dev_attr.attr,
	&sensor_dev_attr_temp2_auto_point2_temp.dev_attr.attr,
	&sensor_dev_attr_temp2_auto_point3_temp.dev_attr.attr,
	NULL
};

static struct attribute_group amc6821_attr_grp = {
	.attrs = amc6821_attrs,
};



/* Return 0 if detection is successful, -ENODEV otherwise */
static int amc6821_detect(
		struct i2c_client *client,
		struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	int address = client->addr;
	int dev_id, comp_id;

	dev_dbg(&adapter->dev, "amc6821_detect called.\n");

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
		dev_dbg(&adapter->dev,
			"amc6821: I2C bus doesn't support byte mode, "
			"skipping.\n");
		return -ENODEV;
	}

	dev_id = i2c_smbus_read_byte_data(client, AMC6821_REG_DEV_ID);
	comp_id = i2c_smbus_read_byte_data(client, AMC6821_REG_COMP_ID);
	if (dev_id != 0x21 || comp_id != 0x49) {
		dev_dbg(&adapter->dev,
			"amc6821: detection failed at 0x%02x.\n",
			address);
		return -ENODEV;
	}

	/*
	 * Bit 7 of the address register is ignored, so we can check the
	 * ID registers again
	 */
	dev_id = i2c_smbus_read_byte_data(client, 0x80 | AMC6821_REG_DEV_ID);
	comp_id = i2c_smbus_read_byte_data(client, 0x80 | AMC6821_REG_COMP_ID);
	if (dev_id != 0x21 || comp_id != 0x49) {
		dev_dbg(&adapter->dev,
			"amc6821: detection failed at 0x%02x.\n",
			address);
		return -ENODEV;
	}

	dev_info(&adapter->dev, "amc6821: chip found at 0x%02x.\n", address);
	strlcpy(info->type, "amc6821", I2C_NAME_SIZE);

	return 0;
}

static int amc6821_probe(
	struct i2c_client *client,
	const struct i2c_device_id *id)
{
	struct amc6821_data *data;
	int err;

	data = devm_kzalloc(&client->dev, sizeof(struct amc6821_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

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

	/*
	 * Initialize the amc6821 chip
	 */
	err = amc6821_init_client(client);
	if (err)
		return err;

	err = sysfs_create_group(&client->dev.kobj, &amc6821_attr_grp);
	if (err)
		return err;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (!IS_ERR(data->hwmon_dev))
		return 0;

	err = PTR_ERR(data->hwmon_dev);
	dev_err(&client->dev, "error registering hwmon device.\n");
	sysfs_remove_group(&client->dev.kobj, &amc6821_attr_grp);
	return err;
}

static int amc6821_remove(struct i2c_client *client)
{
	struct amc6821_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &amc6821_attr_grp);

	return 0;
}


static int amc6821_init_client(struct i2c_client *client)
{
	int config;
	int err = -EIO;

	if (init) {
		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF4);

		if (config < 0) {
				dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
				return err;
		}

		config |= AMC6821_CONF4_MODE;

		if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF4,
				config)) {
			dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
			return err;
		}

		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF3);

		if (config < 0) {
			dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
			return err;
		}

		dev_info(&client->dev, "Revision %d\n", config & 0x0f);

		config &= ~AMC6821_CONF3_THERM_FAN_EN;

		if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF3,
				config)) {
			dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
			return err;
		}

		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF2);

		if (config < 0) {
			dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
			return err;
		}

		config &= ~AMC6821_CONF2_RTFIE;
		config &= ~AMC6821_CONF2_LTOIE;
		config &= ~AMC6821_CONF2_RTOIE;
		if (i2c_smbus_write_byte_data(client,
				AMC6821_REG_CONF2, config)) {
			dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
			return err;
		}

		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);

		if (config < 0) {
			dev_err(&client->dev,
			"Error reading configuration register, aborting.\n");
			return err;
		}

		config &= ~AMC6821_CONF1_THERMOVIE;
		config &= ~AMC6821_CONF1_FANIE;
		config |= AMC6821_CONF1_START;
		if (pwminv)
			config |= AMC6821_CONF1_PWMINV;
		else
			config &= ~AMC6821_CONF1_PWMINV;

		if (i2c_smbus_write_byte_data(
				client, AMC6821_REG_CONF1, config)) {
			dev_err(&client->dev,
			"Configuration register write error, aborting.\n");
			return err;
		}
	}
	return 0;
}


static struct amc6821_data *amc6821_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct amc6821_data *data = i2c_get_clientdata(client);
	int timeout = HZ;
	u8 reg;
	int i;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + timeout) ||
			!data->valid) {

		for (i = 0; i < TEMP_IDX_LEN; i++)
			data->temp[i] = i2c_smbus_read_byte_data(client,
				temp_reg[i]);

		data->stat1 = i2c_smbus_read_byte_data(client,
			AMC6821_REG_STAT1);
		data->stat2 = i2c_smbus_read_byte_data(client,
			AMC6821_REG_STAT2);

		data->pwm1 = i2c_smbus_read_byte_data(client,
			AMC6821_REG_DCY);
		for (i = 0; i < FAN1_IDX_LEN; i++) {
			data->fan[i] = i2c_smbus_read_byte_data(
					client,
					fan_reg_low[i]);
			data->fan[i] += i2c_smbus_read_byte_data(
					client,
					fan_reg_hi[i]) << 8;
		}
		data->fan1_div = i2c_smbus_read_byte_data(client,
			AMC6821_REG_CONF4);
		data->fan1_div = data->fan1_div & AMC6821_CONF4_PSPR ? 4 : 2;

		data->pwm1_auto_point_pwm[0] = 0;
		data->pwm1_auto_point_pwm[2] = 255;
		data->pwm1_auto_point_pwm[1] = i2c_smbus_read_byte_data(client,
			AMC6821_REG_DCY_LOW_TEMP);

		data->temp1_auto_point_temp[0] =
			i2c_smbus_read_byte_data(client,
					AMC6821_REG_PSV_TEMP);
		data->temp2_auto_point_temp[0] =
				data->temp1_auto_point_temp[0];
		reg = i2c_smbus_read_byte_data(client,
			AMC6821_REG_LTEMP_FAN_CTRL);
		data->temp1_auto_point_temp[1] = (reg & 0xF8) >> 1;
		reg &= 0x07;
		reg = 0x20 >> reg;
		if (reg > 0)
			data->temp1_auto_point_temp[2] =
				data->temp1_auto_point_temp[1] +
				(data->pwm1_auto_point_pwm[2] -
				data->pwm1_auto_point_pwm[1]) / reg;
		else
			data->temp1_auto_point_temp[2] = 255;

		reg = i2c_smbus_read_byte_data(client,
			AMC6821_REG_RTEMP_FAN_CTRL);
		data->temp2_auto_point_temp[1] = (reg & 0xF8) >> 1;
		reg &= 0x07;
		reg = 0x20 >> reg;
		if (reg > 0)
			data->temp2_auto_point_temp[2] =
				data->temp2_auto_point_temp[1] +
				(data->pwm1_auto_point_pwm[2] -
				data->pwm1_auto_point_pwm[1]) / reg;
		else
			data->temp2_auto_point_temp[2] = 255;

		reg = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
		reg = (reg >> 5) & 0x3;
		switch (reg) {
		case 0: /*open loop: software sets pwm1*/
			data->pwm1_auto_channels_temp = 0;
			data->pwm1_enable = 1;
			break;
		case 2: /*closed loop: remote T (temp2)*/
			data->pwm1_auto_channels_temp = 2;
			data->pwm1_enable = 2;
			break;
		case 3: /*closed loop: local and remote T (temp2)*/
			data->pwm1_auto_channels_temp = 3;
			data->pwm1_enable = 3;
			break;
		case 1: /*
			 * semi-open loop: software sets rpm, chip controls
			 * pwm1, currently not implemented
			 */
			data->pwm1_auto_channels_temp = 0;
			data->pwm1_enable = 0;
			break;
		}

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

module_i2c_driver(amc6821_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("T. Mertelj <tomaz.mertelj@guest.arnes.si>");
MODULE_DESCRIPTION("Texas Instruments amc6821 hwmon driver");