aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/smsc47m1.c
blob: b5aa38dd7ab90fe06a9cfbfb9d0bb6323a5237c4 (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
/*
 * smsc47m1.c - Part of lm_sensors, Linux kernel modules
 *		for hardware monitoring
 *
 * Supports the SMSC LPC47B27x, LPC47M10x, LPC47M112, LPC47M13x,
 * LPC47M14x, LPC47M15x, LPC47M192, LPC47M292 and LPC47M997
 * Super-I/O chips.
 *
 * Copyright (C) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
 * Copyright (C) 2004-2007 Jean Delvare <khali@linux-fr.org>
 * Ported to Linux 2.6 by Gabriele Gorla <gorlik@yahoo.com>
 *			and Jean Delvare
 *
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/acpi.h>
#include <linux/io.h>

static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");

static struct platform_device *pdev;

#define DRVNAME "smsc47m1"
enum chips { smsc47m1, smsc47m2 };

/* Super-I/0 registers and commands */

#define REG	0x2e	/* The register to read/write */
#define VAL	0x2f	/* The value to read/write */

static inline void
superio_outb(int reg, int val)
{
	outb(reg, REG);
	outb(val, VAL);
}

static inline int
superio_inb(int reg)
{
	outb(reg, REG);
	return inb(VAL);
}

/* logical device for fans is 0x0A */
#define superio_select() superio_outb(0x07, 0x0A)

static inline void
superio_enter(void)
{
	outb(0x55, REG);
}

static inline void
superio_exit(void)
{
	outb(0xAA, REG);
}

#define SUPERIO_REG_ACT		0x30
#define SUPERIO_REG_BASE	0x60
#define SUPERIO_REG_DEVID	0x20
#define SUPERIO_REG_DEVREV	0x21

/* Logical device registers */

#define SMSC_EXTENT		0x80

/* nr is 0 or 1 in the macros below */
#define SMSC47M1_REG_ALARM		0x04
#define SMSC47M1_REG_TPIN(nr)		(0x34 - (nr))
#define SMSC47M1_REG_PPIN(nr)		(0x36 - (nr))
#define SMSC47M1_REG_FANDIV		0x58

static const u8 SMSC47M1_REG_FAN[3]		= { 0x59, 0x5a, 0x6b };
static const u8 SMSC47M1_REG_FAN_PRELOAD[3]	= { 0x5b, 0x5c, 0x6c };
static const u8 SMSC47M1_REG_PWM[3]		= { 0x56, 0x57, 0x69 };

#define SMSC47M2_REG_ALARM6		0x09
#define SMSC47M2_REG_TPIN1		0x38
#define SMSC47M2_REG_TPIN2		0x37
#define SMSC47M2_REG_TPIN3		0x2d
#define SMSC47M2_REG_PPIN3		0x2c
#define SMSC47M2_REG_FANDIV3		0x6a

#define MIN_FROM_REG(reg, div)		((reg) >= 192 ? 0 : \
					 983040 / ((192 - (reg)) * (div)))
#define FAN_FROM_REG(reg, div, preload)	((reg) <= (preload) || (reg) == 255 ? \
					 0 : \
					 983040 / (((reg) - (preload)) * (div)))
#define DIV_FROM_REG(reg)		(1 << (reg))
#define PWM_FROM_REG(reg)		(((reg) & 0x7E) << 1)
#define PWM_EN_FROM_REG(reg)		((~(reg)) & 0x01)
#define PWM_TO_REG(reg)			(((reg) >> 1) & 0x7E)

struct smsc47m1_data {
	unsigned short addr;
	const char *name;
	enum chips type;
	struct device *hwmon_dev;

	struct mutex update_lock;
	unsigned long last_updated;	/* In jiffies */

	u8 fan[3];		/* Register value */
	u8 fan_preload[3];	/* Register value */
	u8 fan_div[3];		/* Register encoding, shifted right */
	u8 alarms;		/* Register encoding */
	u8 pwm[3];		/* Register value (bit 0 is disable) */
};

struct smsc47m1_sio_data {
	enum chips type;
	u8 activate;		/* Remember initial device state */
};


static int __exit smsc47m1_remove(struct platform_device *pdev);
static struct smsc47m1_data *smsc47m1_update_device(struct device *dev,
		int init);

static inline int smsc47m1_read_value(struct smsc47m1_data *data, u8 reg)
{
	return inb_p(data->addr + reg);
}

static inline void smsc47m1_write_value(struct smsc47m1_data *data, u8 reg,
		u8 value)
{
	outb_p(value, data->addr + reg);
}

static struct platform_driver smsc47m1_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= DRVNAME,
	},
	.remove		= __exit_p(smsc47m1_remove),
};

static ssize_t get_fan(struct device *dev, struct device_attribute
		       *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	int nr = attr->index;
	/*
	 * This chip (stupidly) stops monitoring fan speed if PWM is
	 * enabled and duty cycle is 0%. This is fine if the monitoring
	 * and control concern the same fan, but troublesome if they are
	 * not (which could as well happen).
	 */
	int rpm = (data->pwm[nr] & 0x7F) == 0x00 ? 0 :
		  FAN_FROM_REG(data->fan[nr],
			       DIV_FROM_REG(data->fan_div[nr]),
			       data->fan_preload[nr]);
	return sprintf(buf, "%d\n", rpm);
}

static ssize_t get_fan_min(struct device *dev, struct device_attribute
			   *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	int nr = attr->index;
	int rpm = MIN_FROM_REG(data->fan_preload[nr],
			       DIV_FROM_REG(data->fan_div[nr]));
	return sprintf(buf, "%d\n", rpm);
}

static ssize_t get_fan_div(struct device *dev, struct device_attribute
			   *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
}

static ssize_t get_fan_alarm(struct device *dev, struct device_attribute
			     *devattr, char *buf)
{
	int bitnr = to_sensor_dev_attr(devattr)->index;
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}

static ssize_t get_pwm(struct device *dev, struct device_attribute
		       *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	return sprintf(buf, "%d\n", PWM_FROM_REG(data->pwm[attr->index]));
}

static ssize_t get_pwm_en(struct device *dev, struct device_attribute
			  *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	return sprintf(buf, "%d\n", PWM_EN_FROM_REG(data->pwm[attr->index]));
}

static ssize_t get_alarms(struct device *dev, struct device_attribute
			  *devattr, char *buf)
{
	struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
	return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t set_fan_min(struct device *dev, struct device_attribute
			   *devattr, const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = dev_get_drvdata(dev);
	int nr = attr->index;
	long rpmdiv;
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err)
		return err;

	mutex_lock(&data->update_lock);
	rpmdiv = val * DIV_FROM_REG(data->fan_div[nr]);

	if (983040 > 192 * rpmdiv || 2 * rpmdiv > 983040) {
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}

	data->fan_preload[nr] = 192 - ((983040 + rpmdiv / 2) / rpmdiv);
	smsc47m1_write_value(data, SMSC47M1_REG_FAN_PRELOAD[nr],
			     data->fan_preload[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

/*
 * Note: we save and restore the fan minimum here, because its value is
 * determined in part by the fan clock divider.  This follows the principle
 * of least surprise; the user doesn't expect the fan minimum to change just
 * because the divider changed.
 */
static ssize_t set_fan_div(struct device *dev, struct device_attribute
			   *devattr, const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = dev_get_drvdata(dev);
	int nr = attr->index;
	long new_div;
	int err;
	long tmp;
	u8 old_div = DIV_FROM_REG(data->fan_div[nr]);

	err = kstrtol(buf, 10, &new_div);
	if (err)
		return err;

	if (new_div == old_div) /* No change */
		return count;

	mutex_lock(&data->update_lock);
	switch (new_div) {
	case 1:
		data->fan_div[nr] = 0;
		break;
	case 2:
		data->fan_div[nr] = 1;
		break;
	case 4:
		data->fan_div[nr] = 2;
		break;
	case 8:
		data->fan_div[nr] = 3;
		break;
	default:
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}

	switch (nr) {
	case 0:
	case 1:
		tmp = smsc47m1_read_value(data, SMSC47M1_REG_FANDIV)
		      & ~(0x03 << (4 + 2 * nr));
		tmp |= data->fan_div[nr] << (4 + 2 * nr);
		smsc47m1_write_value(data, SMSC47M1_REG_FANDIV, tmp);
		break;
	case 2:
		tmp = smsc47m1_read_value(data, SMSC47M2_REG_FANDIV3) & 0xCF;
		tmp |= data->fan_div[2] << 4;
		smsc47m1_write_value(data, SMSC47M2_REG_FANDIV3, tmp);
		break;
	}

	/* Preserve fan min */
	tmp = 192 - (old_div * (192 - data->fan_preload[nr])
		     + new_div / 2) / new_div;
	data->fan_preload[nr] = SENSORS_LIMIT(tmp, 0, 191);
	smsc47m1_write_value(data, SMSC47M1_REG_FAN_PRELOAD[nr],
			     data->fan_preload[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t set_pwm(struct device *dev, struct device_attribute
		       *devattr, const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = dev_get_drvdata(dev);
	int nr = attr->index;
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err)
		return err;

	if (val < 0 || val > 255)
		return -EINVAL;

	mutex_lock(&data->update_lock);
	data->pwm[nr] &= 0x81; /* Preserve additional bits */
	data->pwm[nr] |= PWM_TO_REG(val);
	smsc47m1_write_value(data, SMSC47M1_REG_PWM[nr],
			     data->pwm[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t set_pwm_en(struct device *dev, struct device_attribute
			  *devattr, const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct smsc47m1_data *data = dev_get_drvdata(dev);
	int nr = attr->index;
	unsigned long val;
	int err;

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

	if (val > 1)
		return -EINVAL;

	mutex_lock(&data->update_lock);
	data->pwm[nr] &= 0xFE; /* preserve the other bits */
	data->pwm[nr] |= !val;
	smsc47m1_write_value(data, SMSC47M1_REG_PWM[nr],
			     data->pwm[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

#define fan_present(offset)						\
static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO, get_fan,	\
		NULL, offset - 1);					\
static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,		\
		get_fan_min, set_fan_min, offset - 1);			\
static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR,		\
		get_fan_div, set_fan_div, offset - 1);			\
static SENSOR_DEVICE_ATTR(fan##offset##_alarm, S_IRUGO, get_fan_alarm,	\
		NULL, offset - 1);					\
static SENSOR_DEVICE_ATTR(pwm##offset, S_IRUGO | S_IWUSR,		\
		get_pwm, set_pwm, offset - 1);				\
static SENSOR_DEVICE_ATTR(pwm##offset##_enable, S_IRUGO | S_IWUSR,	\
		get_pwm_en, set_pwm_en, offset - 1)

fan_present(1);
fan_present(2);
fan_present(3);

static DEVICE_ATTR(alarms, S_IRUGO, get_alarms, NULL);

static ssize_t show_name(struct device *dev, struct device_attribute
			 *devattr, char *buf)
{
	struct smsc47m1_data *data = dev_get_drvdata(dev);

	return sprintf(buf, "%s\n", data->name);
}
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

static struct attribute *smsc47m1_attributes_fan1[] = {
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan1_min.dev_attr.attr,
	&sensor_dev_attr_fan1_div.dev_attr.attr,
	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_fan1 = {
	.attrs = smsc47m1_attributes_fan1,
};

static struct attribute *smsc47m1_attributes_fan2[] = {
	&sensor_dev_attr_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan2_min.dev_attr.attr,
	&sensor_dev_attr_fan2_div.dev_attr.attr,
	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_fan2 = {
	.attrs = smsc47m1_attributes_fan2,
};

static struct attribute *smsc47m1_attributes_fan3[] = {
	&sensor_dev_attr_fan3_input.dev_attr.attr,
	&sensor_dev_attr_fan3_min.dev_attr.attr,
	&sensor_dev_attr_fan3_div.dev_attr.attr,
	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_fan3 = {
	.attrs = smsc47m1_attributes_fan3,
};

static struct attribute *smsc47m1_attributes_pwm1[] = {
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_pwm1 = {
	.attrs = smsc47m1_attributes_pwm1,
};

static struct attribute *smsc47m1_attributes_pwm2[] = {
	&sensor_dev_attr_pwm2.dev_attr.attr,
	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_pwm2 = {
	.attrs = smsc47m1_attributes_pwm2,
};

static struct attribute *smsc47m1_attributes_pwm3[] = {
	&sensor_dev_attr_pwm3.dev_attr.attr,
	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
	NULL
};

static const struct attribute_group smsc47m1_group_pwm3 = {
	.attrs = smsc47m1_attributes_pwm3,
};

static struct attribute *smsc47m1_attributes[] = {
	&dev_attr_alarms.attr,
	&dev_attr_name.attr,
	NULL
};

static const struct attribute_group smsc47m1_group = {
	.attrs = smsc47m1_attributes,
};

static int __init smsc47m1_find(struct smsc47m1_sio_data *sio_data)
{
	u8 val;
	unsigned short addr;

	superio_enter();
	val = force_id ? force_id : superio_inb(SUPERIO_REG_DEVID);

	/*
	 * SMSC LPC47M10x/LPC47M112/LPC47M13x (device id 0x59), LPC47M14x
	 * (device id 0x5F) and LPC47B27x (device id 0x51) have fan control.
	 * The LPC47M15x and LPC47M192 chips "with hardware monitoring block"
	 * can do much more besides (device id 0x60).
	 * The LPC47M997 is undocumented, but seems to be compatible with
	 * the LPC47M192, and has the same device id.
	 * The LPC47M292 (device id 0x6B) is somewhat compatible, but it
	 * supports a 3rd fan, and the pin configuration registers are
	 * unfortunately different.
	 * The LPC47M233 has the same device id (0x6B) but is not compatible.
	 * We check the high bit of the device revision register to
	 * differentiate them.
	 */
	switch (val) {
	case 0x51:
		pr_info("Found SMSC LPC47B27x\n");
		sio_data->type = smsc47m1;
		break;
	case 0x59:
		pr_info("Found SMSC LPC47M10x/LPC47M112/LPC47M13x\n");
		sio_data->type = smsc47m1;
		break;
	case 0x5F:
		pr_info("Found SMSC LPC47M14x\n");
		sio_data->type = smsc47m1;
		break;
	case 0x60:
		pr_info("Found SMSC LPC47M15x/LPC47M192/LPC47M997\n");
		sio_data->type = smsc47m1;
		break;
	case 0x6B:
		if (superio_inb(SUPERIO_REG_DEVREV) & 0x80) {
			pr_debug("Found SMSC LPC47M233, unsupported\n");
			superio_exit();
			return -ENODEV;
		}

		pr_info("Found SMSC LPC47M292\n");
		sio_data->type = smsc47m2;
		break;
	default:
		superio_exit();
		return -ENODEV;
	}

	superio_select();
	addr = (superio_inb(SUPERIO_REG_BASE) << 8)
	      |  superio_inb(SUPERIO_REG_BASE + 1);
	if (addr == 0) {
		pr_info("Device address not set, will not use\n");
		superio_exit();
		return -ENODEV;
	}

	/*
	 * Enable only if address is set (needed at least on the
	 * Compaq Presario S4000NX)
	 */
	sio_data->activate = superio_inb(SUPERIO_REG_ACT);
	if ((sio_data->activate & 0x01) == 0) {
		pr_info("Enabling device\n");
		superio_outb(SUPERIO_REG_ACT, sio_data->activate | 0x01);
	}

	superio_exit();
	return addr;
}

/* Restore device to its initial state */
static void smsc47m1_restore(const struct smsc47m1_sio_data *sio_data)
{
	if ((sio_data->activate & 0x01) == 0) {
		superio_enter();
		superio_select();

		pr_info("Disabling device\n");
		superio_outb(SUPERIO_REG_ACT, sio_data->activate);

		superio_exit();
	}
}

#define CHECK		1
#define REQUEST		2
#define RELEASE		3

/*
 * This function can be used to:
 *  - test for resource conflicts with ACPI
 *  - request the resources
 *  - release the resources
 * We only allocate the I/O ports we really need, to minimize the risk of
 * conflicts with ACPI or with other drivers.
 */
static int smsc47m1_handle_resources(unsigned short address, enum chips type,
				     int action, struct device *dev)
{
	static const u8 ports_m1[] = {
		/* register, region length */
		0x04, 1,
		0x33, 4,
		0x56, 7,
	};

	static const u8 ports_m2[] = {
		/* register, region length */
		0x04, 1,
		0x09, 1,
		0x2c, 2,
		0x35, 4,
		0x56, 7,
		0x69, 4,
	};

	int i, ports_size, err;
	const u8 *ports;

	switch (type) {
	case smsc47m1:
	default:
		ports = ports_m1;
		ports_size = ARRAY_SIZE(ports_m1);
		break;
	case smsc47m2:
		ports = ports_m2;
		ports_size = ARRAY_SIZE(ports_m2);
		break;
	}

	for (i = 0; i + 1 < ports_size; i += 2) {
		unsigned short start = address + ports[i];
		unsigned short len = ports[i + 1];

		switch (action) {
		case CHECK:
			/* Only check for conflicts */
			err = acpi_check_region(start, len, DRVNAME);
			if (err)
				return err;
			break;
		case REQUEST:
			/* Request the resources */
			if (!request_region(start, len, DRVNAME)) {
				dev_err(dev, "Region 0x%hx-0x%hx already in "
					"use!\n", start, start + len);

				/* Undo all requests */
				for (i -= 2; i >= 0; i -= 2)
					release_region(address + ports[i],
						       ports[i + 1]);
				return -EBUSY;
			}
			break;
		case RELEASE:
			/* Release the resources */
			release_region(start, len);
			break;
		}
	}

	return 0;
}

static void smsc47m1_remove_files(struct device *dev)
{
	sysfs_remove_group(&dev->kobj, &smsc47m1_group);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan1);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan2);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan3);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm1);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm2);
	sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm3);
}

static int __init smsc47m1_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct smsc47m1_sio_data *sio_data = dev->platform_data;
	struct smsc47m1_data *data;
	struct resource *res;
	int err;
	int fan1, fan2, fan3, pwm1, pwm2, pwm3;

	static const char * const names[] = {
		"smsc47m1",
		"smsc47m2",
	};

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	err = smsc47m1_handle_resources(res->start, sio_data->type,
					REQUEST, dev);
	if (err < 0)
		return err;

	data = kzalloc(sizeof(struct smsc47m1_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto error_release;
	}

	data->addr = res->start;
	data->type = sio_data->type;
	data->name = names[sio_data->type];
	mutex_init(&data->update_lock);
	platform_set_drvdata(pdev, data);

	/*
	 * If no function is properly configured, there's no point in
	 * actually registering the chip.
	 */
	pwm1 = (smsc47m1_read_value(data, SMSC47M1_REG_PPIN(0)) & 0x05)
	       == 0x04;
	pwm2 = (smsc47m1_read_value(data, SMSC47M1_REG_PPIN(1)) & 0x05)
	       == 0x04;
	if (data->type == smsc47m2) {
		fan1 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN1)
			& 0x0d) == 0x09;
		fan2 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN2)
			& 0x0d) == 0x09;
		fan3 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN3)
			& 0x0d) == 0x0d;
		pwm3 = (smsc47m1_read_value(data, SMSC47M2_REG_PPIN3)
			& 0x0d) == 0x08;
	} else {
		fan1 = (smsc47m1_read_value(data, SMSC47M1_REG_TPIN(0))
			& 0x05) == 0x05;
		fan2 = (smsc47m1_read_value(data, SMSC47M1_REG_TPIN(1))
			& 0x05) == 0x05;
		fan3 = 0;
		pwm3 = 0;
	}
	if (!(fan1 || fan2 || fan3 || pwm1 || pwm2 || pwm3)) {
		dev_warn(dev, "Device not configured, will not use\n");
		err = -ENODEV;
		goto error_free;
	}

	/*
	 * Some values (fan min, clock dividers, pwm registers) may be
	 * needed before any update is triggered, so we better read them
	 * at least once here. We don't usually do it that way, but in
	 * this particular case, manually reading 5 registers out of 8
	 * doesn't make much sense and we're better using the existing
	 * function.
	 */
	smsc47m1_update_device(dev, 1);

	/* Register sysfs hooks */
	if (fan1) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_fan1);
		if (err)
			goto error_remove_files;
	} else
		dev_dbg(dev, "Fan 1 not enabled by hardware, skipping\n");

	if (fan2) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_fan2);
		if (err)
			goto error_remove_files;
	} else
		dev_dbg(dev, "Fan 2 not enabled by hardware, skipping\n");

	if (fan3) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_fan3);
		if (err)
			goto error_remove_files;
	} else if (data->type == smsc47m2)
		dev_dbg(dev, "Fan 3 not enabled by hardware, skipping\n");

	if (pwm1) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_pwm1);
		if (err)
			goto error_remove_files;
	} else
		dev_dbg(dev, "PWM 1 not enabled by hardware, skipping\n");

	if (pwm2) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_pwm2);
		if (err)
			goto error_remove_files;
	} else
		dev_dbg(dev, "PWM 2 not enabled by hardware, skipping\n");

	if (pwm3) {
		err = sysfs_create_group(&dev->kobj,
					 &smsc47m1_group_pwm3);
		if (err)
			goto error_remove_files;
	} else if (data->type == smsc47m2)
		dev_dbg(dev, "PWM 3 not enabled by hardware, skipping\n");

	err = sysfs_create_group(&dev->kobj, &smsc47m1_group);
	if (err)
		goto error_remove_files;

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

	return 0;

error_remove_files:
	smsc47m1_remove_files(dev);
error_free:
	platform_set_drvdata(pdev, NULL);
	kfree(data);
error_release:
	smsc47m1_handle_resources(res->start, sio_data->type, RELEASE, dev);
	return err;
}

static int __exit smsc47m1_remove(struct platform_device *pdev)
{
	struct smsc47m1_data *data = platform_get_drvdata(pdev);
	struct resource *res;

	hwmon_device_unregister(data->hwmon_dev);
	smsc47m1_remove_files(&pdev->dev);

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	smsc47m1_handle_resources(res->start, data->type, RELEASE, &pdev->dev);
	platform_set_drvdata(pdev, NULL);
	kfree(data);

	return 0;
}

static struct smsc47m1_data *smsc47m1_update_device(struct device *dev,
		int init)
{
	struct smsc47m1_data *data = dev_get_drvdata(dev);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2) || init) {
		int i, fan_nr;
		fan_nr = data->type == smsc47m2 ? 3 : 2;

		for (i = 0; i < fan_nr; i++) {
			data->fan[i] = smsc47m1_read_value(data,
				       SMSC47M1_REG_FAN[i]);
			data->fan_preload[i] = smsc47m1_read_value(data,
					       SMSC47M1_REG_FAN_PRELOAD[i]);
			data->pwm[i] = smsc47m1_read_value(data,
				       SMSC47M1_REG_PWM[i]);
		}

		i = smsc47m1_read_value(data, SMSC47M1_REG_FANDIV);
		data->fan_div[0] = (i >> 4) & 0x03;
		data->fan_div[1] = i >> 6;

		data->alarms = smsc47m1_read_value(data,
			       SMSC47M1_REG_ALARM) >> 6;
		/* Clear alarms if needed */
		if (data->alarms)
			smsc47m1_write_value(data, SMSC47M1_REG_ALARM, 0xC0);

		if (fan_nr >= 3) {
			data->fan_div[2] = (smsc47m1_read_value(data,
					    SMSC47M2_REG_FANDIV3) >> 4) & 0x03;
			data->alarms |= (smsc47m1_read_value(data,
					 SMSC47M2_REG_ALARM6) & 0x40) >> 4;
			/* Clear alarm if needed */
			if (data->alarms & 0x04)
				smsc47m1_write_value(data,
						     SMSC47M2_REG_ALARM6,
						     0x40);
		}

		data->last_updated = jiffies;
	}

	mutex_unlock(&data->update_lock);
	return data;
}

static int __init smsc47m1_device_add(unsigned short address,
				      const struct smsc47m1_sio_data *sio_data)
{
	struct resource res = {
		.start	= address,
		.end	= address + SMSC_EXTENT - 1,
		.name	= DRVNAME,
		.flags	= IORESOURCE_IO,
	};
	int err;

	err = smsc47m1_handle_resources(address, sio_data->type, CHECK, NULL);
	if (err)
		goto exit;

	pdev = platform_device_alloc(DRVNAME, address);
	if (!pdev) {
		err = -ENOMEM;
		pr_err("Device allocation failed\n");
		goto exit;
	}

	err = platform_device_add_resources(pdev, &res, 1);
	if (err) {
		pr_err("Device resource addition failed (%d)\n", err);
		goto exit_device_put;
	}

	err = platform_device_add_data(pdev, sio_data,
				       sizeof(struct smsc47m1_sio_data));
	if (err) {
		pr_err("Platform data allocation failed\n");
		goto exit_device_put;
	}

	err = platform_device_add(pdev);
	if (err) {
		pr_err("Device addition failed (%d)\n", err);
		goto exit_device_put;
	}

	return 0;

exit_device_put:
	platform_device_put(pdev);
exit:
	return err;
}

static int __init sm_smsc47m1_init(void)
{
	int err;
	unsigned short address;
	struct smsc47m1_sio_data sio_data;

	err = smsc47m1_find(&sio_data);
	if (err < 0)
		return err;
	address = err;

	/* Sets global pdev as a side effect */
	err = smsc47m1_device_add(address, &sio_data);
	if (err)
		return err;

	err = platform_driver_probe(&smsc47m1_driver, smsc47m1_probe);
	if (err)
		goto exit_device;

	return 0;

exit_device:
	platform_device_unregister(pdev);
	smsc47m1_restore(&sio_data);
	return err;
}

static void __exit sm_smsc47m1_exit(void)
{
	platform_driver_unregister(&smsc47m1_driver);
	smsc47m1_restore(pdev->dev.platform_data);
	platform_device_unregister(pdev);
}

MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
MODULE_DESCRIPTION("SMSC LPC47M1xx fan sensors driver");
MODULE_LICENSE("GPL");

module_init(sm_smsc47m1_init);
module_exit(sm_smsc47m1_exit);