summaryrefslogtreecommitdiffstats
path: root/drivers/power/avs/smartreflex.c
blob: c7d4417104232d864b464708f149b81ce3a796d1 (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
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
/*
 * OMAP SmartReflex Voltage Control
 *
 * Author: Thara Gopinath	<thara@ti.com>
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 * Thara Gopinath <thara@ti.com>
 *
 * Copyright (C) 2008 Nokia Corporation
 * Kalle Jokiniemi
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Lesly A M <x0080970@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/power/smartreflex.h>

#include <plat/cpu.h>

#define SMARTREFLEX_NAME_LEN	16
#define NVALUE_NAME_LEN		40
#define SR_DISABLE_TIMEOUT	200

/* sr_list contains all the instances of smartreflex module */
static LIST_HEAD(sr_list);

static struct omap_sr_class_data *sr_class;
static struct omap_sr_pmic_data *sr_pmic_data;
static struct dentry		*sr_dbg_dir;

static inline void sr_write_reg(struct omap_sr *sr, unsigned offset, u32 value)
{
	__raw_writel(value, (sr->base + offset));
}

static inline void sr_modify_reg(struct omap_sr *sr, unsigned offset, u32 mask,
					u32 value)
{
	u32 reg_val;

	/*
	 * Smartreflex error config register is special as it contains
	 * certain status bits which if written a 1 into means a clear
	 * of those bits. So in order to make sure no accidental write of
	 * 1 happens to those status bits, do a clear of them in the read
	 * value. This mean this API doesn't rewrite values in these bits
	 * if they are currently set, but does allow the caller to write
	 * those bits.
	 */
	if (sr->ip_type == SR_TYPE_V1 && offset == ERRCONFIG_V1)
		mask |= ERRCONFIG_STATUS_V1_MASK;
	else if (sr->ip_type == SR_TYPE_V2 && offset == ERRCONFIG_V2)
		mask |= ERRCONFIG_VPBOUNDINTST_V2;

	reg_val = __raw_readl(sr->base + offset);
	reg_val &= ~mask;

	value &= mask;

	reg_val |= value;

	__raw_writel(reg_val, (sr->base + offset));
}

static inline u32 sr_read_reg(struct omap_sr *sr, unsigned offset)
{
	return __raw_readl(sr->base + offset);
}

static struct omap_sr *_sr_lookup(struct voltagedomain *voltdm)
{
	struct omap_sr *sr_info;

	if (!voltdm) {
		pr_err("%s: Null voltage domain passed!\n", __func__);
		return ERR_PTR(-EINVAL);
	}

	list_for_each_entry(sr_info, &sr_list, node) {
		if (voltdm == sr_info->voltdm)
			return sr_info;
	}

	return ERR_PTR(-ENODATA);
}

static irqreturn_t sr_interrupt(int irq, void *data)
{
	struct omap_sr *sr_info = data;
	u32 status = 0;

	switch (sr_info->ip_type) {
	case SR_TYPE_V1:
		/* Read the status bits */
		status = sr_read_reg(sr_info, ERRCONFIG_V1);

		/* Clear them by writing back */
		sr_write_reg(sr_info, ERRCONFIG_V1, status);
		break;
	case SR_TYPE_V2:
		/* Read the status bits */
		status = sr_read_reg(sr_info, IRQSTATUS);

		/* Clear them by writing back */
		sr_write_reg(sr_info, IRQSTATUS, status);
		break;
	default:
		dev_err(&sr_info->pdev->dev, "UNKNOWN IP type %d\n",
			sr_info->ip_type);
		return IRQ_NONE;
	}

	if (sr_class->notify)
		sr_class->notify(sr_info, status);

	return IRQ_HANDLED;
}

static void sr_set_clk_length(struct omap_sr *sr)
{
	struct clk *sys_ck;
	u32 sys_clk_speed;

	if (cpu_is_omap34xx())
		sys_ck = clk_get(NULL, "sys_ck");
	else
		sys_ck = clk_get(NULL, "sys_clkin_ck");

	if (IS_ERR(sys_ck)) {
		dev_err(&sr->pdev->dev, "%s: unable to get sys clk\n",
			__func__);
		return;
	}

	sys_clk_speed = clk_get_rate(sys_ck);
	clk_put(sys_ck);

	switch (sys_clk_speed) {
	case 12000000:
		sr->clk_length = SRCLKLENGTH_12MHZ_SYSCLK;
		break;
	case 13000000:
		sr->clk_length = SRCLKLENGTH_13MHZ_SYSCLK;
		break;
	case 19200000:
		sr->clk_length = SRCLKLENGTH_19MHZ_SYSCLK;
		break;
	case 26000000:
		sr->clk_length = SRCLKLENGTH_26MHZ_SYSCLK;
		break;
	case 38400000:
		sr->clk_length = SRCLKLENGTH_38MHZ_SYSCLK;
		break;
	default:
		dev_err(&sr->pdev->dev, "%s: Invalid sysclk value: %d\n",
			__func__, sys_clk_speed);
		break;
	}
}

static void sr_set_regfields(struct omap_sr *sr)
{
	/*
	 * For time being these values are defined in smartreflex.h
	 * and populated during init. May be they can be moved to board
	 * file or pmic specific data structure. In that case these structure
	 * fields will have to be populated using the pdata or pmic structure.
	 */
	if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
		sr->err_weight = OMAP3430_SR_ERRWEIGHT;
		sr->err_maxlimit = OMAP3430_SR_ERRMAXLIMIT;
		sr->accum_data = OMAP3430_SR_ACCUMDATA;
		if (!(strcmp(sr->name, "smartreflex_mpu_iva"))) {
			sr->senn_avgweight = OMAP3430_SR1_SENNAVGWEIGHT;
			sr->senp_avgweight = OMAP3430_SR1_SENPAVGWEIGHT;
		} else {
			sr->senn_avgweight = OMAP3430_SR2_SENNAVGWEIGHT;
			sr->senp_avgweight = OMAP3430_SR2_SENPAVGWEIGHT;
		}
	}
}

static void sr_start_vddautocomp(struct omap_sr *sr)
{
	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
		dev_warn(&sr->pdev->dev,
			"%s: smartreflex class driver not registered\n",
			__func__);
		return;
	}

	if (!sr_class->enable(sr))
		sr->autocomp_active = true;
}

static void sr_stop_vddautocomp(struct omap_sr *sr)
{
	if (!sr_class || !(sr_class->disable)) {
		dev_warn(&sr->pdev->dev,
			"%s: smartreflex class driver not registered\n",
			__func__);
		return;
	}

	if (sr->autocomp_active) {
		sr_class->disable(sr, 1);
		sr->autocomp_active = false;
	}
}

/*
 * This function handles the intializations which have to be done
 * only when both sr device and class driver regiter has
 * completed. This will be attempted to be called from both sr class
 * driver register and sr device intializtion API's. Only one call
 * will ultimately succeed.
 *
 * Currently this function registers interrupt handler for a particular SR
 * if smartreflex class driver is already registered and has
 * requested for interrupts and the SR interrupt line in present.
 */
static int sr_late_init(struct omap_sr *sr_info)
{
	struct omap_sr_data *pdata = sr_info->pdev->dev.platform_data;
	struct resource *mem;
	int ret = 0;

	if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
		ret = request_irq(sr_info->irq, sr_interrupt,
				  0, sr_info->name, sr_info);
		if (ret)
			goto error;
		disable_irq(sr_info->irq);
	}

	if (pdata && pdata->enable_on_init)
		sr_start_vddautocomp(sr_info);

	return ret;

error:
	iounmap(sr_info->base);
	mem = platform_get_resource(sr_info->pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, resource_size(mem));
	list_del(&sr_info->node);
	dev_err(&sr_info->pdev->dev, "%s: ERROR in registering"
		"interrupt handler. Smartreflex will"
		"not function as desired\n", __func__);
	kfree(sr_info);

	return ret;
}

static void sr_v1_disable(struct omap_sr *sr)
{
	int timeout = 0;
	int errconf_val = ERRCONFIG_MCUACCUMINTST | ERRCONFIG_MCUVALIDINTST |
			ERRCONFIG_MCUBOUNDINTST;

	/* Enable MCUDisableAcknowledge interrupt */
	sr_modify_reg(sr, ERRCONFIG_V1,
			ERRCONFIG_MCUDISACKINTEN, ERRCONFIG_MCUDISACKINTEN);

	/* SRCONFIG - disable SR */
	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);

	/* Disable all other SR interrupts and clear the status as needed */
	if (sr_read_reg(sr, ERRCONFIG_V1) & ERRCONFIG_VPBOUNDINTST_V1)
		errconf_val |= ERRCONFIG_VPBOUNDINTST_V1;
	sr_modify_reg(sr, ERRCONFIG_V1,
			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
			ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_VPBOUNDINTEN_V1),
			errconf_val);

	/*
	 * Wait for SR to be disabled.
	 * wait until ERRCONFIG.MCUDISACKINTST = 1. Typical latency is 1us.
	 */
	sr_test_cond_timeout((sr_read_reg(sr, ERRCONFIG_V1) &
			     ERRCONFIG_MCUDISACKINTST), SR_DISABLE_TIMEOUT,
			     timeout);

	if (timeout >= SR_DISABLE_TIMEOUT)
		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
			__func__);

	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
	sr_modify_reg(sr, ERRCONFIG_V1, ERRCONFIG_MCUDISACKINTEN,
			ERRCONFIG_MCUDISACKINTST);
}

static void sr_v2_disable(struct omap_sr *sr)
{
	int timeout = 0;

	/* Enable MCUDisableAcknowledge interrupt */
	sr_write_reg(sr, IRQENABLE_SET, IRQENABLE_MCUDISABLEACKINT);

	/* SRCONFIG - disable SR */
	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, 0x0);

	/*
	 * Disable all other SR interrupts and clear the status
	 * write to status register ONLY on need basis - only if status
	 * is set.
	 */
	if (sr_read_reg(sr, ERRCONFIG_V2) & ERRCONFIG_VPBOUNDINTST_V2)
		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
			ERRCONFIG_VPBOUNDINTST_V2);
	else
		sr_modify_reg(sr, ERRCONFIG_V2, ERRCONFIG_VPBOUNDINTEN_V2,
				0x0);
	sr_write_reg(sr, IRQENABLE_CLR, (IRQENABLE_MCUACCUMINT |
			IRQENABLE_MCUVALIDINT |
			IRQENABLE_MCUBOUNDSINT));
	sr_write_reg(sr, IRQSTATUS, (IRQSTATUS_MCUACCUMINT |
			IRQSTATUS_MCVALIDINT |
			IRQSTATUS_MCBOUNDSINT));

	/*
	 * Wait for SR to be disabled.
	 * wait until IRQSTATUS.MCUDISACKINTST = 1. Typical latency is 1us.
	 */
	sr_test_cond_timeout((sr_read_reg(sr, IRQSTATUS) &
			     IRQSTATUS_MCUDISABLEACKINT), SR_DISABLE_TIMEOUT,
			     timeout);

	if (timeout >= SR_DISABLE_TIMEOUT)
		dev_warn(&sr->pdev->dev, "%s: Smartreflex disable timedout\n",
			__func__);

	/* Disable MCUDisableAcknowledge interrupt & clear pending interrupt */
	sr_write_reg(sr, IRQENABLE_CLR, IRQENABLE_MCUDISABLEACKINT);
	sr_write_reg(sr, IRQSTATUS, IRQSTATUS_MCUDISABLEACKINT);
}

static struct omap_sr_nvalue_table *sr_retrieve_nvalue_row(
				struct omap_sr *sr, u32 efuse_offs)
{
	int i;

	if (!sr->nvalue_table) {
		dev_warn(&sr->pdev->dev, "%s: Missing ntarget value table\n",
			__func__);
		return NULL;
	}

	for (i = 0; i < sr->nvalue_count; i++) {
		if (sr->nvalue_table[i].efuse_offs == efuse_offs)
			return &sr->nvalue_table[i];
	}

	return NULL;
}

/* Public Functions */

/**
 * sr_configure_errgen() - Configures the smrtreflex to perform AVS using the
 *			 error generator module.
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the smartreflex class driver to
 * configure the error generator module inside the smartreflex module.
 * SR settings if using the ERROR module inside Smartreflex.
 * SR CLASS 3 by default uses only the ERROR module where as
 * SR CLASS 2 can choose between ERROR module and MINMAXAVG
 * module. Returns 0 on success and error value in case of failure.
 */
int sr_configure_errgen(struct voltagedomain *voltdm)
{
	u32 sr_config, sr_errconfig, errconfig_offs;
	u32 vpboundint_en, vpboundint_st;
	u32 senp_en = 0, senn_en = 0;
	u8 senp_shift, senn_shift;
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return PTR_ERR(sr);
	}

	if (!sr->clk_length)
		sr_set_clk_length(sr);

	senp_en = sr->senp_mod;
	senn_en = sr->senn_mod;

	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
		SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN;

	switch (sr->ip_type) {
	case SR_TYPE_V1:
		sr_config |= SRCONFIG_DELAYCTRL;
		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
		errconfig_offs = ERRCONFIG_V1;
		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
		break;
	case SR_TYPE_V2:
		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
		errconfig_offs = ERRCONFIG_V2;
		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
		break;
	default:
		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
			"module without specifying the ip\n", __func__);
		return -EINVAL;
	}

	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
	sr_write_reg(sr, SRCONFIG, sr_config);
	sr_errconfig = (sr->err_weight << ERRCONFIG_ERRWEIGHT_SHIFT) |
		(sr->err_maxlimit << ERRCONFIG_ERRMAXLIMIT_SHIFT) |
		(sr->err_minlimit <<  ERRCONFIG_ERRMINLIMIT_SHIFT);
	sr_modify_reg(sr, errconfig_offs, (SR_ERRWEIGHT_MASK |
		SR_ERRMAXLIMIT_MASK | SR_ERRMINLIMIT_MASK),
		sr_errconfig);

	/* Enabling the interrupts if the ERROR module is used */
	sr_modify_reg(sr, errconfig_offs, (vpboundint_en | vpboundint_st),
		      vpboundint_en);

	return 0;
}

/**
 * sr_disable_errgen() - Disables SmartReflex AVS module's errgen component
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the smartreflex class driver to
 * disable the error generator module inside the smartreflex module.
 *
 * Returns 0 on success and error value in case of failure.
 */
int sr_disable_errgen(struct voltagedomain *voltdm)
{
	u32 errconfig_offs;
	u32 vpboundint_en, vpboundint_st;
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return PTR_ERR(sr);
	}

	switch (sr->ip_type) {
	case SR_TYPE_V1:
		errconfig_offs = ERRCONFIG_V1;
		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V1;
		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V1;
		break;
	case SR_TYPE_V2:
		errconfig_offs = ERRCONFIG_V2;
		vpboundint_en = ERRCONFIG_VPBOUNDINTEN_V2;
		vpboundint_st = ERRCONFIG_VPBOUNDINTST_V2;
		break;
	default:
		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
			"module without specifying the ip\n", __func__);
		return -EINVAL;
	}

	/* Disable the interrupts of ERROR module */
	sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);

	/* Disable the Sensor and errorgen */
	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);

	return 0;
}

/**
 * sr_configure_minmax() - Configures the smrtreflex to perform AVS using the
 *			 minmaxavg module.
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the smartreflex class driver to
 * configure the minmaxavg module inside the smartreflex module.
 * SR settings if using the ERROR module inside Smartreflex.
 * SR CLASS 3 by default uses only the ERROR module where as
 * SR CLASS 2 can choose between ERROR module and MINMAXAVG
 * module. Returns 0 on success and error value in case of failure.
 */
int sr_configure_minmax(struct voltagedomain *voltdm)
{
	u32 sr_config, sr_avgwt;
	u32 senp_en = 0, senn_en = 0;
	u8 senp_shift, senn_shift;
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return PTR_ERR(sr);
	}

	if (!sr->clk_length)
		sr_set_clk_length(sr);

	senp_en = sr->senp_mod;
	senn_en = sr->senn_mod;

	sr_config = (sr->clk_length << SRCONFIG_SRCLKLENGTH_SHIFT) |
		SRCONFIG_SENENABLE |
		(sr->accum_data << SRCONFIG_ACCUMDATA_SHIFT);

	switch (sr->ip_type) {
	case SR_TYPE_V1:
		sr_config |= SRCONFIG_DELAYCTRL;
		senn_shift = SRCONFIG_SENNENABLE_V1_SHIFT;
		senp_shift = SRCONFIG_SENPENABLE_V1_SHIFT;
		break;
	case SR_TYPE_V2:
		senn_shift = SRCONFIG_SENNENABLE_V2_SHIFT;
		senp_shift = SRCONFIG_SENPENABLE_V2_SHIFT;
		break;
	default:
		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
			"module without specifying the ip\n", __func__);
		return -EINVAL;
	}

	sr_config |= ((senn_en << senn_shift) | (senp_en << senp_shift));
	sr_write_reg(sr, SRCONFIG, sr_config);
	sr_avgwt = (sr->senp_avgweight << AVGWEIGHT_SENPAVGWEIGHT_SHIFT) |
		(sr->senn_avgweight << AVGWEIGHT_SENNAVGWEIGHT_SHIFT);
	sr_write_reg(sr, AVGWEIGHT, sr_avgwt);

	/*
	 * Enabling the interrupts if MINMAXAVG module is used.
	 * TODO: check if all the interrupts are mandatory
	 */
	switch (sr->ip_type) {
	case SR_TYPE_V1:
		sr_modify_reg(sr, ERRCONFIG_V1,
			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUVALIDINTEN |
			ERRCONFIG_MCUBOUNDINTEN),
			(ERRCONFIG_MCUACCUMINTEN | ERRCONFIG_MCUACCUMINTST |
			 ERRCONFIG_MCUVALIDINTEN | ERRCONFIG_MCUVALIDINTST |
			 ERRCONFIG_MCUBOUNDINTEN | ERRCONFIG_MCUBOUNDINTST));
		break;
	case SR_TYPE_V2:
		sr_write_reg(sr, IRQSTATUS,
			IRQSTATUS_MCUACCUMINT | IRQSTATUS_MCVALIDINT |
			IRQSTATUS_MCBOUNDSINT | IRQSTATUS_MCUDISABLEACKINT);
		sr_write_reg(sr, IRQENABLE_SET,
			IRQENABLE_MCUACCUMINT | IRQENABLE_MCUVALIDINT |
			IRQENABLE_MCUBOUNDSINT | IRQENABLE_MCUDISABLEACKINT);
		break;
	default:
		dev_err(&sr->pdev->dev, "%s: Trying to Configure smartreflex"
			"module without specifying the ip\n", __func__);
		return -EINVAL;
	}

	return 0;
}

/**
 * sr_enable() - Enables the smartreflex module.
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 * @volt:	The voltage at which the Voltage domain associated with
 *		the smartreflex module is operating at.
 *		This is required only to program the correct Ntarget value.
 *
 * This API is to be called from the smartreflex class driver to
 * enable a smartreflex module. Returns 0 on success. Returns error
 * value if the voltage passed is wrong or if ntarget value is wrong.
 */
int sr_enable(struct voltagedomain *voltdm, unsigned long volt)
{
	struct omap_volt_data *volt_data;
	struct omap_sr *sr = _sr_lookup(voltdm);
	struct omap_sr_nvalue_table *nvalue_row;
	int ret;

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return PTR_ERR(sr);
	}

	volt_data = omap_voltage_get_voltdata(sr->voltdm, volt);

	if (IS_ERR(volt_data)) {
		dev_warn(&sr->pdev->dev, "%s: Unable to get voltage table"
			"for nominal voltage %ld\n", __func__, volt);
		return PTR_ERR(volt_data);
	}

	nvalue_row = sr_retrieve_nvalue_row(sr, volt_data->sr_efuse_offs);

	if (!nvalue_row) {
		dev_warn(&sr->pdev->dev, "%s: failure getting SR data for this voltage %ld\n",
			 __func__, volt);
		return -ENODATA;
	}

	/* errminlimit is opp dependent and hence linked to voltage */
	sr->err_minlimit = nvalue_row->errminlimit;

	pm_runtime_get_sync(&sr->pdev->dev);

	/* Check if SR is already enabled. If yes do nothing */
	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE)
		return 0;

	/* Configure SR */
	ret = sr_class->configure(sr);
	if (ret)
		return ret;

	sr_write_reg(sr, NVALUERECIPROCAL, nvalue_row->nvalue);

	/* SRCONFIG - enable SR */
	sr_modify_reg(sr, SRCONFIG, SRCONFIG_SRENABLE, SRCONFIG_SRENABLE);
	return 0;
}

/**
 * sr_disable() - Disables the smartreflex module.
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the smartreflex class driver to
 * disable a smartreflex module.
 */
void sr_disable(struct voltagedomain *voltdm)
{
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return;
	}

	/* Check if SR clocks are already disabled. If yes do nothing */
	if (pm_runtime_suspended(&sr->pdev->dev))
		return;

	/*
	 * Disable SR if only it is indeed enabled. Else just
	 * disable the clocks.
	 */
	if (sr_read_reg(sr, SRCONFIG) & SRCONFIG_SRENABLE) {
		switch (sr->ip_type) {
		case SR_TYPE_V1:
			sr_v1_disable(sr);
			break;
		case SR_TYPE_V2:
			sr_v2_disable(sr);
			break;
		default:
			dev_err(&sr->pdev->dev, "UNKNOWN IP type %d\n",
				sr->ip_type);
		}
	}

	pm_runtime_put_sync_suspend(&sr->pdev->dev);
}

/**
 * sr_register_class() - API to register a smartreflex class parameters.
 * @class_data:	The structure containing various sr class specific data.
 *
 * This API is to be called by the smartreflex class driver to register itself
 * with the smartreflex driver during init. Returns 0 on success else the
 * error value.
 */
int sr_register_class(struct omap_sr_class_data *class_data)
{
	struct omap_sr *sr_info;

	if (!class_data) {
		pr_warning("%s:, Smartreflex class data passed is NULL\n",
			__func__);
		return -EINVAL;
	}

	if (sr_class) {
		pr_warning("%s: Smartreflex class driver already registered\n",
			__func__);
		return -EBUSY;
	}

	sr_class = class_data;

	/*
	 * Call into late init to do intializations that require
	 * both sr driver and sr class driver to be initiallized.
	 */
	list_for_each_entry(sr_info, &sr_list, node)
		sr_late_init(sr_info);

	return 0;
}

/**
 * omap_sr_enable() -  API to enable SR clocks and to call into the
 *			registered smartreflex class enable API.
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the kernel in order to enable
 * a particular smartreflex module. This API will do the initial
 * configurations to turn on the smartreflex module and in turn call
 * into the registered smartreflex class enable API.
 */
void omap_sr_enable(struct voltagedomain *voltdm)
{
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return;
	}

	if (!sr->autocomp_active)
		return;

	if (!sr_class || !(sr_class->enable) || !(sr_class->configure)) {
		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
			"registered\n", __func__);
		return;
	}

	sr_class->enable(sr);
}

/**
 * omap_sr_disable() - API to disable SR without resetting the voltage
 *			processor voltage
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the kernel in order to disable
 * a particular smartreflex module. This API will in turn call
 * into the registered smartreflex class disable API. This API will tell
 * the smartreflex class disable not to reset the VP voltage after
 * disabling smartreflex.
 */
void omap_sr_disable(struct voltagedomain *voltdm)
{
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return;
	}

	if (!sr->autocomp_active)
		return;

	if (!sr_class || !(sr_class->disable)) {
		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
			"registered\n", __func__);
		return;
	}

	sr_class->disable(sr, 0);
}

/**
 * omap_sr_disable_reset_volt() - API to disable SR and reset the
 *				voltage processor voltage
 * @voltdm:	VDD pointer to which the SR module to be configured belongs to.
 *
 * This API is to be called from the kernel in order to disable
 * a particular smartreflex module. This API will in turn call
 * into the registered smartreflex class disable API. This API will tell
 * the smartreflex class disable to reset the VP voltage after
 * disabling smartreflex.
 */
void omap_sr_disable_reset_volt(struct voltagedomain *voltdm)
{
	struct omap_sr *sr = _sr_lookup(voltdm);

	if (IS_ERR(sr)) {
		pr_warning("%s: omap_sr struct for voltdm not found\n",	__func__);
		return;
	}

	if (!sr->autocomp_active)
		return;

	if (!sr_class || !(sr_class->disable)) {
		dev_warn(&sr->pdev->dev, "%s: smartreflex class driver not"
			"registered\n", __func__);
		return;
	}

	sr_class->disable(sr, 1);
}

/**
 * omap_sr_register_pmic() - API to register pmic specific info.
 * @pmic_data:	The structure containing pmic specific data.
 *
 * This API is to be called from the PMIC specific code to register with
 * smartreflex driver pmic specific info. Currently the only info required
 * is the smartreflex init on the PMIC side.
 */
void omap_sr_register_pmic(struct omap_sr_pmic_data *pmic_data)
{
	if (!pmic_data) {
		pr_warning("%s: Trying to register NULL PMIC data structure"
			"with smartreflex\n", __func__);
		return;
	}

	sr_pmic_data = pmic_data;
}

/* PM Debug FS entries to enable and disable smartreflex. */
static int omap_sr_autocomp_show(void *data, u64 *val)
{
	struct omap_sr *sr_info = data;

	if (!sr_info) {
		pr_warning("%s: omap_sr struct not found\n", __func__);
		return -EINVAL;
	}

	*val = sr_info->autocomp_active;

	return 0;
}

static int omap_sr_autocomp_store(void *data, u64 val)
{
	struct omap_sr *sr_info = data;

	if (!sr_info) {
		pr_warning("%s: omap_sr struct not found\n", __func__);
		return -EINVAL;
	}

	/* Sanity check */
	if (val > 1) {
		pr_warning("%s: Invalid argument %lld\n", __func__, val);
		return -EINVAL;
	}

	/* control enable/disable only if there is a delta in value */
	if (sr_info->autocomp_active != val) {
		if (!val)
			sr_stop_vddautocomp(sr_info);
		else
			sr_start_vddautocomp(sr_info);
	}

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(pm_sr_fops, omap_sr_autocomp_show,
			omap_sr_autocomp_store, "%llu\n");

static int __init omap_sr_probe(struct platform_device *pdev)
{
	struct omap_sr *sr_info;
	struct omap_sr_data *pdata = pdev->dev.platform_data;
	struct resource *mem, *irq;
	struct dentry *nvalue_dir;
	int i, ret = 0;

	sr_info = kzalloc(sizeof(struct omap_sr), GFP_KERNEL);
	if (!sr_info) {
		dev_err(&pdev->dev, "%s: unable to allocate sr_info\n",
			__func__);
		return -ENOMEM;
	}

	platform_set_drvdata(pdev, sr_info);

	if (!pdata) {
		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
		ret = -EINVAL;
		goto err_free_devinfo;
	}

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
		dev_err(&pdev->dev, "%s: no mem resource\n", __func__);
		ret = -ENODEV;
		goto err_free_devinfo;
	}

	mem = request_mem_region(mem->start, resource_size(mem),
					dev_name(&pdev->dev));
	if (!mem) {
		dev_err(&pdev->dev, "%s: no mem region\n", __func__);
		ret = -EBUSY;
		goto err_free_devinfo;
	}

	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

	pm_runtime_enable(&pdev->dev);
	pm_runtime_irq_safe(&pdev->dev);

	sr_info->name = kasprintf(GFP_KERNEL, "%s", pdata->name);
	if (!sr_info->name) {
		dev_err(&pdev->dev, "%s: Unable to alloc SR instance name\n",
			__func__);
		ret = -ENOMEM;
		goto err_release_region;
	}

	sr_info->pdev = pdev;
	sr_info->srid = pdev->id;
	sr_info->voltdm = pdata->voltdm;
	sr_info->nvalue_table = pdata->nvalue_table;
	sr_info->nvalue_count = pdata->nvalue_count;
	sr_info->senn_mod = pdata->senn_mod;
	sr_info->senp_mod = pdata->senp_mod;
	sr_info->autocomp_active = false;
	sr_info->ip_type = pdata->ip_type;
	sr_info->base = ioremap(mem->start, resource_size(mem));
	if (!sr_info->base) {
		dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
		ret = -ENOMEM;
		goto err_free_name;
	}

	if (irq)
		sr_info->irq = irq->start;

	sr_set_clk_length(sr_info);
	sr_set_regfields(sr_info);

	list_add(&sr_info->node, &sr_list);

	/*
	 * Call into late init to do intializations that require
	 * both sr driver and sr class driver to be initiallized.
	 */
	if (sr_class) {
		ret = sr_late_init(sr_info);
		if (ret) {
			pr_warning("%s: Error in SR late init\n", __func__);
			goto err_iounmap;
		}
	}

	dev_info(&pdev->dev, "%s: SmartReflex driver initialized\n", __func__);
	if (!sr_dbg_dir) {
		sr_dbg_dir = debugfs_create_dir("smartreflex", NULL);
		if (IS_ERR_OR_NULL(sr_dbg_dir)) {
			ret = PTR_ERR(sr_dbg_dir);
			pr_err("%s:sr debugfs dir creation failed(%d)\n",
				__func__, ret);
			goto err_iounmap;
		}
	}

	sr_info->dbg_dir = debugfs_create_dir(sr_info->name, sr_dbg_dir);
	if (IS_ERR_OR_NULL(sr_info->dbg_dir)) {
		dev_err(&pdev->dev, "%s: Unable to create debugfs directory\n",
			__func__);
		ret = PTR_ERR(sr_info->dbg_dir);
		goto err_debugfs;
	}

	(void) debugfs_create_file("autocomp", S_IRUGO | S_IWUSR,
			sr_info->dbg_dir, (void *)sr_info, &pm_sr_fops);
	(void) debugfs_create_x32("errweight", S_IRUGO, sr_info->dbg_dir,
			&sr_info->err_weight);
	(void) debugfs_create_x32("errmaxlimit", S_IRUGO, sr_info->dbg_dir,
			&sr_info->err_maxlimit);

	nvalue_dir = debugfs_create_dir("nvalue", sr_info->dbg_dir);
	if (IS_ERR_OR_NULL(nvalue_dir)) {
		dev_err(&pdev->dev, "%s: Unable to create debugfs directory"
			"for n-values\n", __func__);
		ret = PTR_ERR(nvalue_dir);
		goto err_debugfs;
	}

	if (sr_info->nvalue_count == 0 || !sr_info->nvalue_table) {
		dev_warn(&pdev->dev, "%s: %s: No Voltage table for the corresponding vdd. Cannot create debugfs entries for n-values\n",
			 __func__, sr_info->name);

		ret = -ENODATA;
		goto err_debugfs;
	}

	for (i = 0; i < sr_info->nvalue_count; i++) {
		char name[NVALUE_NAME_LEN + 1];

		snprintf(name, sizeof(name), "volt_%lu",
				sr_info->nvalue_table[i].volt_nominal);
		(void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
				&(sr_info->nvalue_table[i].nvalue));
		snprintf(name, sizeof(name), "errminlimit_%lu",
			 sr_info->nvalue_table[i].volt_nominal);
		(void) debugfs_create_x32(name, S_IRUGO | S_IWUSR, nvalue_dir,
				&(sr_info->nvalue_table[i].errminlimit));

	}

	return ret;

err_debugfs:
	debugfs_remove_recursive(sr_info->dbg_dir);
err_iounmap:
	list_del(&sr_info->node);
	iounmap(sr_info->base);
err_free_name:
	kfree(sr_info->name);
err_release_region:
	release_mem_region(mem->start, resource_size(mem));
err_free_devinfo:
	kfree(sr_info);

	return ret;
}

static int __devexit omap_sr_remove(struct platform_device *pdev)
{
	struct omap_sr_data *pdata = pdev->dev.platform_data;
	struct omap_sr *sr_info;
	struct resource *mem;

	if (!pdata) {
		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
		return -EINVAL;
	}

	sr_info = _sr_lookup(pdata->voltdm);
	if (IS_ERR(sr_info)) {
		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
			__func__);
		return PTR_ERR(sr_info);
	}

	if (sr_info->autocomp_active)
		sr_stop_vddautocomp(sr_info);
	if (sr_info->dbg_dir)
		debugfs_remove_recursive(sr_info->dbg_dir);

	list_del(&sr_info->node);
	iounmap(sr_info->base);
	kfree(sr_info->name);
	kfree(sr_info);
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, resource_size(mem));

	return 0;
}

static void __devexit omap_sr_shutdown(struct platform_device *pdev)
{
	struct omap_sr_data *pdata = pdev->dev.platform_data;
	struct omap_sr *sr_info;

	if (!pdata) {
		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
		return;
	}

	sr_info = _sr_lookup(pdata->voltdm);
	if (IS_ERR(sr_info)) {
		dev_warn(&pdev->dev, "%s: omap_sr struct not found\n",
			__func__);
		return;
	}

	if (sr_info->autocomp_active)
		sr_stop_vddautocomp(sr_info);

	return;
}

static struct platform_driver smartreflex_driver = {
	.remove         = omap_sr_remove,
	.shutdown	= omap_sr_shutdown,
	.driver		= {
		.name	= "smartreflex",
	},
};

static int __init sr_init(void)
{
	int ret = 0;

	/*
	 * sr_init is a late init. If by then a pmic specific API is not
	 * registered either there is no need for anything to be done on
	 * the PMIC side or somebody has forgotten to register a PMIC
	 * handler. Warn for the second condition.
	 */
	if (sr_pmic_data && sr_pmic_data->sr_pmic_init)
		sr_pmic_data->sr_pmic_init();
	else
		pr_warning("%s: No PMIC hook to init smartreflex\n", __func__);

	ret = platform_driver_probe(&smartreflex_driver, omap_sr_probe);
	if (ret) {
		pr_err("%s: platform driver register failed for SR\n",
			__func__);
		return ret;
	}

	return 0;
}
late_initcall(sr_init);

static void __exit sr_exit(void)
{
	platform_driver_unregister(&smartreflex_driver);
}
module_exit(sr_exit);

MODULE_DESCRIPTION("OMAP Smartreflex Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("Texas Instruments Inc");