summaryrefslogtreecommitdiff
path: root/drivers/hwtracing/coresight/coresight-cti-core.c
blob: 61dbc1afd8da506a84f6ade2b58be670f1c651bf (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018 Linaro Limited, All rights reserved.
 * Author: Mike Leach <mike.leach@linaro.org>
 */

#include <linux/amba/bus.h>
#include <linux/atomic.h>
#include <linux/bits.h>
#include <linux/coresight.h>
#include <linux/cpu_pm.h>
#include <linux/cpuhotplug.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/spinlock.h>

#include "coresight-priv.h"
#include "coresight-cti.h"

/**
 * CTI devices can be associated with a PE, or be connected to CoreSight
 * hardware. We have a list of all CTIs irrespective of CPU bound or
 * otherwise.
 *
 * We assume that the non-CPU CTIs are always powered as we do with sinks etc.
 *
 * We leave the client to figure out if all the CTIs are interconnected with
 * the same CTM, in general this is the case but does not always have to be.
 */

/* net of CTI devices connected via CTM */
static LIST_HEAD(ect_net);

/* protect the list */
static DEFINE_MUTEX(ect_mutex);

#define csdev_to_cti_drvdata(csdev)	\
	dev_get_drvdata(csdev->dev.parent)

/* power management handling */
static int nr_cti_cpu;

/* quick lookup list for CPU bound CTIs when power handling */
static struct cti_drvdata *cti_cpu_drvdata[NR_CPUS];

/*
 * CTI naming. CTI bound to cores will have the name cti_cpu<N> where
 * N is the CPU ID. System CTIs will have the name cti_sys<I> where I
 * is an index allocated by order of discovery.
 *
 * CTI device name list - for CTI not bound to cores.
 */
DEFINE_CORESIGHT_DEVLIST(cti_sys_devs, "cti_sys");

/* write set of regs to hardware - call with spinlock claimed */
void cti_write_all_hw_regs(struct cti_drvdata *drvdata)
{
	struct cti_config *config = &drvdata->config;
	int i;

	CS_UNLOCK(drvdata->base);

	/* disable CTI before writing registers */
	writel_relaxed(0, drvdata->base + CTICONTROL);

	/* write the CTI trigger registers */
	for (i = 0; i < config->nr_trig_max; i++) {
		writel_relaxed(config->ctiinen[i], drvdata->base + CTIINEN(i));
		writel_relaxed(config->ctiouten[i],
			       drvdata->base + CTIOUTEN(i));
	}

	/* other regs */
	writel_relaxed(config->ctigate, drvdata->base + CTIGATE);
	writel_relaxed(config->asicctl, drvdata->base + ASICCTL);
	writel_relaxed(config->ctiappset, drvdata->base + CTIAPPSET);

	/* re-enable CTI */
	writel_relaxed(1, drvdata->base + CTICONTROL);

	CS_LOCK(drvdata->base);
}

/* write regs to hardware and enable */
static int cti_enable_hw(struct cti_drvdata *drvdata)
{
	struct cti_config *config = &drvdata->config;
	struct device *dev = &drvdata->csdev->dev;
	unsigned long flags;
	int rc = 0;

	pm_runtime_get_sync(dev->parent);
	spin_lock_irqsave(&drvdata->spinlock, flags);

	/* no need to do anything if enabled or unpowered*/
	if (config->hw_enabled || !config->hw_powered)
		goto cti_state_unchanged;

	/* claim the device */
	rc = coresight_claim_device(drvdata->base);
	if (rc)
		goto cti_err_not_enabled;

	cti_write_all_hw_regs(drvdata);

	config->hw_enabled = true;
	atomic_inc(&drvdata->config.enable_req_count);
	spin_unlock_irqrestore(&drvdata->spinlock, flags);
	return rc;

cti_state_unchanged:
	atomic_inc(&drvdata->config.enable_req_count);

	/* cannot enable due to error */
cti_err_not_enabled:
	spin_unlock_irqrestore(&drvdata->spinlock, flags);
	pm_runtime_put(dev->parent);
	return rc;
}

/* re-enable CTI on CPU when using CPU hotplug */
static void cti_cpuhp_enable_hw(struct cti_drvdata *drvdata)
{
	struct cti_config *config = &drvdata->config;

	spin_lock(&drvdata->spinlock);
	config->hw_powered = true;

	/* no need to do anything if no enable request */
	if (!atomic_read(&drvdata->config.enable_req_count))
		goto cti_hp_not_enabled;

	/* try to claim the device */
	if (coresight_claim_device(drvdata->base))
		goto cti_hp_not_enabled;

	cti_write_all_hw_regs(drvdata);
	config->hw_enabled = true;
	spin_unlock(&drvdata->spinlock);
	return;

	/* did not re-enable due to no claim / no request */
cti_hp_not_enabled:
	spin_unlock(&drvdata->spinlock);
}

/* disable hardware */
static int cti_disable_hw(struct cti_drvdata *drvdata)
{
	struct cti_config *config = &drvdata->config;
	struct device *dev = &drvdata->csdev->dev;

	spin_lock(&drvdata->spinlock);

	/* check refcount - disable on 0 */
	if (atomic_dec_return(&drvdata->config.enable_req_count) > 0)
		goto cti_not_disabled;

	/* no need to do anything if disabled or cpu unpowered */
	if (!config->hw_enabled || !config->hw_powered)
		goto cti_not_disabled;

	CS_UNLOCK(drvdata->base);

	/* disable CTI */
	writel_relaxed(0, drvdata->base + CTICONTROL);
	config->hw_enabled = false;

	coresight_disclaim_device_unlocked(drvdata->base);
	CS_LOCK(drvdata->base);
	spin_unlock(&drvdata->spinlock);
	pm_runtime_put(dev);
	return 0;

	/* not disabled this call */
cti_not_disabled:
	spin_unlock(&drvdata->spinlock);
	return 0;
}

void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value)
{
	CS_UNLOCK(drvdata->base);
	writel_relaxed(value, drvdata->base + offset);
	CS_LOCK(drvdata->base);
}

void cti_write_intack(struct device *dev, u32 ackval)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
	struct cti_config *config = &drvdata->config;

	spin_lock(&drvdata->spinlock);
	/* write if enabled */
	if (cti_active(config))
		cti_write_single_reg(drvdata, CTIINTACK, ackval);
	spin_unlock(&drvdata->spinlock);
}

/*
 * Look at the HW DEVID register for some of the HW settings.
 * DEVID[15:8] - max number of in / out triggers.
 */
#define CTI_DEVID_MAXTRIGS(devid_val) ((int) BMVAL(devid_val, 8, 15))

/* DEVID[19:16] - number of CTM channels */
#define CTI_DEVID_CTMCHANNELS(devid_val) ((int) BMVAL(devid_val, 16, 19))

static void cti_set_default_config(struct device *dev,
				   struct cti_drvdata *drvdata)
{
	struct cti_config *config = &drvdata->config;
	u32 devid;

	devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
	config->nr_trig_max = CTI_DEVID_MAXTRIGS(devid);

	/*
	 * no current hardware should exceed this, but protect the driver
	 * in case of fault / out of spec hw
	 */
	if (config->nr_trig_max > CTIINOUTEN_MAX) {
		dev_warn_once(dev,
			"Limiting HW MaxTrig value(%d) to driver max(%d)\n",
			config->nr_trig_max, CTIINOUTEN_MAX);
		config->nr_trig_max = CTIINOUTEN_MAX;
	}

	config->nr_ctm_channels = CTI_DEVID_CTMCHANNELS(devid);

	/* Most regs default to 0 as zalloc'ed except...*/
	config->trig_filter_enable = true;
	config->ctigate = GENMASK(config->nr_ctm_channels - 1, 0);
	atomic_set(&config->enable_req_count, 0);
}

/*
 * Add a connection entry to the list of connections for this
 * CTI device.
 */
int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
			     struct cti_trig_con *tc,
			     struct coresight_device *csdev,
			     const char *assoc_dev_name)
{
	struct cti_device *cti_dev = &drvdata->ctidev;

	tc->con_dev = csdev;
	/*
	 * Prefer actual associated CS device dev name to supplied value -
	 * which is likely to be node name / other conn name.
	 */
	if (csdev)
		tc->con_dev_name = dev_name(&csdev->dev);
	else if (assoc_dev_name != NULL) {
		tc->con_dev_name = devm_kstrdup(dev,
						assoc_dev_name, GFP_KERNEL);
		if (!tc->con_dev_name)
			return -ENOMEM;
	}
	list_add_tail(&tc->node, &cti_dev->trig_cons);
	cti_dev->nr_trig_con++;

	/* add connection usage bit info to overall info */
	drvdata->config.trig_in_use |= tc->con_in->used_mask;
	drvdata->config.trig_out_use |= tc->con_out->used_mask;

	return 0;
}

/* create a trigger connection with appropriately sized signal groups */
struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
					   int out_sigs)
{
	struct cti_trig_con *tc = NULL;
	struct cti_trig_grp *in = NULL, *out = NULL;

	tc = devm_kzalloc(dev, sizeof(struct cti_trig_con), GFP_KERNEL);
	if (!tc)
		return tc;

	in = devm_kzalloc(dev,
			  offsetof(struct cti_trig_grp, sig_types[in_sigs]),
			  GFP_KERNEL);
	if (!in)
		return NULL;

	out = devm_kzalloc(dev,
			   offsetof(struct cti_trig_grp, sig_types[out_sigs]),
			   GFP_KERNEL);
	if (!out)
		return NULL;

	tc->con_in = in;
	tc->con_out = out;
	tc->con_in->nr_sigs = in_sigs;
	tc->con_out->nr_sigs = out_sigs;
	return tc;
}

/*
 * Add a default connection if nothing else is specified.
 * single connection based on max in/out info, no assoc device
 */
int cti_add_default_connection(struct device *dev, struct cti_drvdata *drvdata)
{
	int ret = 0;
	int n_trigs = drvdata->config.nr_trig_max;
	u32 n_trig_mask = GENMASK(n_trigs - 1, 0);
	struct cti_trig_con *tc = NULL;

	/*
	 * Assume max trigs for in and out,
	 * all used, default sig types allocated
	 */
	tc = cti_allocate_trig_con(dev, n_trigs, n_trigs);
	if (!tc)
		return -ENOMEM;

	tc->con_in->used_mask = n_trig_mask;
	tc->con_out->used_mask = n_trig_mask;
	ret = cti_add_connection_entry(dev, drvdata, tc, NULL, "default");
	return ret;
}

/** cti channel api **/
/* attach/detach channel from trigger - write through if enabled. */
int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
			enum cti_trig_dir direction, u32 channel_idx,
			u32 trigger_idx)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
	struct cti_config *config = &drvdata->config;
	u32 trig_bitmask;
	u32 chan_bitmask;
	u32 reg_value;
	int reg_offset;

	/* ensure indexes in range */
	if ((channel_idx >= config->nr_ctm_channels) ||
	   (trigger_idx >= config->nr_trig_max))
		return -EINVAL;

	trig_bitmask = BIT(trigger_idx);

	/* ensure registered triggers and not out filtered */
	if (direction == CTI_TRIG_IN)	{
		if (!(trig_bitmask & config->trig_in_use))
			return -EINVAL;
	} else {
		if (!(trig_bitmask & config->trig_out_use))
			return -EINVAL;

		if ((config->trig_filter_enable) &&
		    (config->trig_out_filter & trig_bitmask))
			return -EINVAL;
	}

	/* update the local register values */
	chan_bitmask = BIT(channel_idx);
	reg_offset = (direction == CTI_TRIG_IN ? CTIINEN(trigger_idx) :
		      CTIOUTEN(trigger_idx));

	spin_lock(&drvdata->spinlock);

	/* read - modify write - the trigger / channel enable value */
	reg_value = direction == CTI_TRIG_IN ? config->ctiinen[trigger_idx] :
		     config->ctiouten[trigger_idx];
	if (op == CTI_CHAN_ATTACH)
		reg_value |= chan_bitmask;
	else
		reg_value &= ~chan_bitmask;

	/* write local copy */
	if (direction == CTI_TRIG_IN)
		config->ctiinen[trigger_idx] = reg_value;
	else
		config->ctiouten[trigger_idx] = reg_value;

	/* write through if enabled */
	if (cti_active(config))
		cti_write_single_reg(drvdata, reg_offset, reg_value);
	spin_unlock(&drvdata->spinlock);
	return 0;
}

int cti_channel_gate_op(struct device *dev, enum cti_chan_gate_op op,
			u32 channel_idx)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
	struct cti_config *config = &drvdata->config;
	u32 chan_bitmask;
	u32 reg_value;
	int err = 0;

	if (channel_idx >= config->nr_ctm_channels)
		return -EINVAL;

	chan_bitmask = BIT(channel_idx);

	spin_lock(&drvdata->spinlock);
	reg_value = config->ctigate;
	switch (op) {
	case CTI_GATE_CHAN_ENABLE:
		reg_value |= chan_bitmask;
		break;

	case CTI_GATE_CHAN_DISABLE:
		reg_value &= ~chan_bitmask;
		break;

	default:
		err = -EINVAL;
		break;
	}
	if (err == 0) {
		config->ctigate = reg_value;
		if (cti_active(config))
			cti_write_single_reg(drvdata, CTIGATE, reg_value);
	}
	spin_unlock(&drvdata->spinlock);
	return err;
}

int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
		      u32 channel_idx)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
	struct cti_config *config = &drvdata->config;
	u32 chan_bitmask;
	u32 reg_value;
	u32 reg_offset;
	int err = 0;

	if (channel_idx >= config->nr_ctm_channels)
		return -EINVAL;

	chan_bitmask = BIT(channel_idx);

	spin_lock(&drvdata->spinlock);
	reg_value = config->ctiappset;
	switch (op) {
	case CTI_CHAN_SET:
		config->ctiappset |= chan_bitmask;
		reg_value  = config->ctiappset;
		reg_offset = CTIAPPSET;
		break;

	case CTI_CHAN_CLR:
		config->ctiappset &= ~chan_bitmask;
		reg_value = chan_bitmask;
		reg_offset = CTIAPPCLEAR;
		break;

	case CTI_CHAN_PULSE:
		config->ctiappset &= ~chan_bitmask;
		reg_value = chan_bitmask;
		reg_offset = CTIAPPPULSE;
		break;

	default:
		err = -EINVAL;
		break;
	}

	if ((err == 0) && cti_active(config))
		cti_write_single_reg(drvdata, reg_offset, reg_value);
	spin_unlock(&drvdata->spinlock);

	return err;
}

static bool cti_add_sysfs_link(struct cti_drvdata *drvdata,
			       struct cti_trig_con *tc)
{
	struct coresight_sysfs_link link_info;
	int link_err = 0;

	link_info.orig = drvdata->csdev;
	link_info.orig_name = tc->con_dev_name;
	link_info.target = tc->con_dev;
	link_info.target_name = dev_name(&drvdata->csdev->dev);

	link_err = coresight_add_sysfs_link(&link_info);
	if (link_err)
		dev_warn(&drvdata->csdev->dev,
			 "Failed to set CTI sysfs link %s<=>%s\n",
			 link_info.orig_name, link_info.target_name);
	return !link_err;
}

static void cti_remove_sysfs_link(struct cti_drvdata *drvdata,
				  struct cti_trig_con *tc)
{
	struct coresight_sysfs_link link_info;

	link_info.orig = drvdata->csdev;
	link_info.orig_name = tc->con_dev_name;
	link_info.target = tc->con_dev;
	link_info.target_name = dev_name(&drvdata->csdev->dev);
	coresight_remove_sysfs_link(&link_info);
}

/*
 * Look for a matching connection device name in the list of connections.
 * If found then swap in the csdev name, set trig con association pointer
 * and return found.
 */
static bool
cti_match_fixup_csdev(struct cti_device *ctidev, const char *node_name,
		      struct coresight_device *csdev)
{
	struct cti_trig_con *tc;
	struct cti_drvdata *drvdata = container_of(ctidev, struct cti_drvdata,
						   ctidev);

	list_for_each_entry(tc, &ctidev->trig_cons, node) {
		if (tc->con_dev_name) {
			if (!strcmp(node_name, tc->con_dev_name)) {
				/* match: so swap in csdev name & dev */
				tc->con_dev_name = dev_name(&csdev->dev);
				tc->con_dev = csdev;
				/* try to set sysfs link */
				if (cti_add_sysfs_link(drvdata, tc))
					return true;
				/* link failed - remove CTI reference */
				tc->con_dev = NULL;
				break;
			}
		}
	}
	return false;
}

/*
 * Search the cti list to add an associated CTI into the supplied CS device
 * This will set the association if CTI declared before the CS device.
 * (called from coresight_register() with coresight_mutex locked).
 */
static void cti_add_assoc_to_csdev(struct coresight_device *csdev)
{
	struct cti_drvdata *ect_item;
	struct cti_device *ctidev;
	const char *node_name = NULL;

	/* protect the list */
	mutex_lock(&ect_mutex);

	/* exit if current is an ECT device.*/
	if ((csdev->type == CORESIGHT_DEV_TYPE_ECT) || list_empty(&ect_net))
		goto cti_add_done;

	/* if we didn't find the csdev previously we used the fwnode name */
	node_name = cti_plat_get_node_name(dev_fwnode(csdev->dev.parent));
	if (!node_name)
		goto cti_add_done;

	/* for each CTI in list... */
	list_for_each_entry(ect_item, &ect_net, node) {
		ctidev = &ect_item->ctidev;
		if (cti_match_fixup_csdev(ctidev, node_name, csdev)) {
			/*
			 * if we found a matching csdev then update the ECT
			 * association pointer for the device with this CTI.
			 */
			csdev->ect_dev = ect_item->csdev;
			break;
		}
	}
cti_add_done:
	mutex_unlock(&ect_mutex);
}

/*
 * Removing the associated devices is easier.
 * A CTI will not have a value for csdev->ect_dev.
 */
static void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
{
	struct cti_drvdata *ctidrv;
	struct cti_trig_con *tc;
	struct cti_device *ctidev;

	mutex_lock(&ect_mutex);
	if (csdev->ect_dev) {
		ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
		ctidev = &ctidrv->ctidev;
		list_for_each_entry(tc, &ctidev->trig_cons, node) {
			if (tc->con_dev == csdev) {
				cti_remove_sysfs_link(ctidrv, tc);
				tc->con_dev = NULL;
				break;
			}
		}
		csdev->ect_dev = NULL;
	}
	mutex_unlock(&ect_mutex);
}

/*
 * Operations to add and remove associated CTI.
 * Register to coresight core driver as call back function.
 */
static struct cti_assoc_op cti_assoc_ops = {
	.add = cti_add_assoc_to_csdev,
	.remove = cti_remove_assoc_from_csdev
};

/*
 * Update the cross references where the associated device was found
 * while we were building the connection info. This will occur if the
 * assoc device was registered before the CTI.
 */
static void cti_update_conn_xrefs(struct cti_drvdata *drvdata)
{
	struct cti_trig_con *tc;
	struct cti_device *ctidev = &drvdata->ctidev;

	list_for_each_entry(tc, &ctidev->trig_cons, node) {
		if (tc->con_dev) {
			/* if we can set the sysfs link */
			if (cti_add_sysfs_link(drvdata, tc))
				/* set the CTI/csdev association */
				coresight_set_assoc_ectdev_mutex(tc->con_dev,
							 drvdata->csdev);
			else
				/* otherwise remove reference from CTI */
				tc->con_dev = NULL;
		}
	}
}

static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)
{
	struct cti_trig_con *tc;
	struct cti_device *ctidev = &drvdata->ctidev;

	list_for_each_entry(tc, &ctidev->trig_cons, node) {
		if (tc->con_dev) {
			coresight_set_assoc_ectdev_mutex(tc->con_dev,
							 NULL);
			cti_remove_sysfs_link(drvdata, tc);
			tc->con_dev = NULL;
		}
	}
}

/** cti PM callbacks **/
static int cti_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
			     void *v)
{
	struct cti_drvdata *drvdata;
	unsigned int cpu = smp_processor_id();
	int notify_res = NOTIFY_OK;

	if (!cti_cpu_drvdata[cpu])
		return NOTIFY_OK;

	drvdata = cti_cpu_drvdata[cpu];

	if (WARN_ON_ONCE(drvdata->ctidev.cpu != cpu))
		return NOTIFY_BAD;

	spin_lock(&drvdata->spinlock);

	switch (cmd) {
	case CPU_PM_ENTER:
		/* CTI regs all static - we have a copy & nothing to save */
		drvdata->config.hw_powered = false;
		if (drvdata->config.hw_enabled)
			coresight_disclaim_device(drvdata->base);
		break;

	case CPU_PM_ENTER_FAILED:
		drvdata->config.hw_powered = true;
		if (drvdata->config.hw_enabled) {
			if (coresight_claim_device(drvdata->base))
				drvdata->config.hw_enabled = false;
		}
		break;

	case CPU_PM_EXIT:
		/* write hardware registers to re-enable. */
		drvdata->config.hw_powered = true;
		drvdata->config.hw_enabled = false;

		/* check enable reference count to enable HW */
		if (atomic_read(&drvdata->config.enable_req_count)) {
			/* check we can claim the device as we re-power */
			if (coresight_claim_device(drvdata->base))
				goto cti_notify_exit;

			drvdata->config.hw_enabled = true;
			cti_write_all_hw_regs(drvdata);
		}
		break;

	default:
		notify_res = NOTIFY_DONE;
		break;
	}

cti_notify_exit:
	spin_unlock(&drvdata->spinlock);
	return notify_res;
}

static struct notifier_block cti_cpu_pm_nb = {
	.notifier_call = cti_cpu_pm_notify,
};

/* CPU HP handlers */
static int cti_starting_cpu(unsigned int cpu)
{
	struct cti_drvdata *drvdata = cti_cpu_drvdata[cpu];

	if (!drvdata)
		return 0;

	cti_cpuhp_enable_hw(drvdata);
	return 0;
}

static int cti_dying_cpu(unsigned int cpu)
{
	struct cti_drvdata *drvdata = cti_cpu_drvdata[cpu];

	if (!drvdata)
		return 0;

	spin_lock(&drvdata->spinlock);
	drvdata->config.hw_powered = false;
	if (drvdata->config.hw_enabled)
		coresight_disclaim_device(drvdata->base);
	spin_unlock(&drvdata->spinlock);
	return 0;
}

static int cti_pm_setup(struct cti_drvdata *drvdata)
{
	int ret;

	if (drvdata->ctidev.cpu == -1)
		return 0;

	if (nr_cti_cpu)
		goto done;

	cpus_read_lock();
	ret = cpuhp_setup_state_nocalls_cpuslocked(
			CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
			"arm/coresight_cti:starting",
			cti_starting_cpu, cti_dying_cpu);
	if (ret) {
		cpus_read_unlock();
		return ret;
	}

	ret = cpu_pm_register_notifier(&cti_cpu_pm_nb);
	cpus_read_unlock();
	if (ret) {
		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
		return ret;
	}

done:
	nr_cti_cpu++;
	cti_cpu_drvdata[drvdata->ctidev.cpu] = drvdata;

	return 0;
}

/* release PM registrations */
static void cti_pm_release(struct cti_drvdata *drvdata)
{
	if (drvdata->ctidev.cpu == -1)
		return;

	cti_cpu_drvdata[drvdata->ctidev.cpu] = NULL;
	if (--nr_cti_cpu == 0) {
		cpu_pm_unregister_notifier(&cti_cpu_pm_nb);
		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
	}
}

/** cti ect operations **/
int cti_enable(struct coresight_device *csdev)
{
	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);

	return cti_enable_hw(drvdata);
}

int cti_disable(struct coresight_device *csdev)
{
	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);

	return cti_disable_hw(drvdata);
}

static const struct coresight_ops_ect cti_ops_ect = {
	.enable = cti_enable,
	.disable = cti_disable,
};

static const struct coresight_ops cti_ops = {
	.ect_ops = &cti_ops_ect,
};

/*
 * Free up CTI specific resources
 * called by dev->release, need to call down to underlying csdev release.
 */
static void cti_device_release(struct device *dev)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
	struct cti_drvdata *ect_item, *ect_tmp;

	mutex_lock(&ect_mutex);
	cti_pm_release(drvdata);

	/* remove from the list */
	list_for_each_entry_safe(ect_item, ect_tmp, &ect_net, node) {
		if (ect_item == drvdata) {
			list_del(&ect_item->node);
			break;
		}
	}
	mutex_unlock(&ect_mutex);

	if (drvdata->csdev_release)
		drvdata->csdev_release(dev);
}
static int cti_remove(struct amba_device *adev)
{
	struct cti_drvdata *drvdata = dev_get_drvdata(&adev->dev);

	mutex_lock(&ect_mutex);
	cti_remove_conn_xrefs(drvdata);
	mutex_unlock(&ect_mutex);

	coresight_unregister(drvdata->csdev);

	return 0;
}

static int cti_probe(struct amba_device *adev, const struct amba_id *id)
{
	int ret = 0;
	void __iomem *base;
	struct device *dev = &adev->dev;
	struct cti_drvdata *drvdata = NULL;
	struct coresight_desc cti_desc;
	struct coresight_platform_data *pdata = NULL;
	struct resource *res = &adev->res;

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

	/* Validity for the resource is already checked by the AMBA core */
	base = devm_ioremap_resource(dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	drvdata->base = base;

	dev_set_drvdata(dev, drvdata);

	/* default CTI device info  */
	drvdata->ctidev.cpu = -1;
	drvdata->ctidev.nr_trig_con = 0;
	drvdata->ctidev.ctm_id = 0;
	INIT_LIST_HEAD(&drvdata->ctidev.trig_cons);

	spin_lock_init(&drvdata->spinlock);

	/* initialise CTI driver config values */
	cti_set_default_config(dev, drvdata);

	pdata = coresight_cti_get_platform_data(dev);
	if (IS_ERR(pdata)) {
		dev_err(dev, "coresight_cti_get_platform_data err\n");
		return  PTR_ERR(pdata);
	}

	/* default to powered - could change on PM notifications */
	drvdata->config.hw_powered = true;

	/* set up device name - will depend if cpu bound or otherwise */
	if (drvdata->ctidev.cpu >= 0)
		cti_desc.name = devm_kasprintf(dev, GFP_KERNEL, "cti_cpu%d",
					       drvdata->ctidev.cpu);
	else
		cti_desc.name = coresight_alloc_device_name(&cti_sys_devs, dev);
	if (!cti_desc.name)
		return -ENOMEM;

	/* setup CPU power management handling for CPU bound CTI devices. */
	ret = cti_pm_setup(drvdata);
	if (ret)
		return ret;

	/* create dynamic attributes for connections */
	ret = cti_create_cons_sysfs(dev, drvdata);
	if (ret) {
		dev_err(dev, "%s: create dynamic sysfs entries failed\n",
			cti_desc.name);
		goto pm_release;
	}

	/* set up coresight component description */
	cti_desc.pdata = pdata;
	cti_desc.type = CORESIGHT_DEV_TYPE_ECT;
	cti_desc.subtype.ect_subtype = CORESIGHT_DEV_SUBTYPE_ECT_CTI;
	cti_desc.ops = &cti_ops;
	cti_desc.groups = drvdata->ctidev.con_groups;
	cti_desc.dev = dev;
	drvdata->csdev = coresight_register(&cti_desc);
	if (IS_ERR(drvdata->csdev)) {
		ret = PTR_ERR(drvdata->csdev);
		goto pm_release;
	}

	/* add to list of CTI devices */
	mutex_lock(&ect_mutex);
	list_add(&drvdata->node, &ect_net);
	/* set any cross references */
	cti_update_conn_xrefs(drvdata);
	mutex_unlock(&ect_mutex);

	/* set up release chain */
	drvdata->csdev_release = drvdata->csdev->dev.release;
	drvdata->csdev->dev.release = cti_device_release;

	/* all done - dec pm refcount */
	pm_runtime_put(&adev->dev);
	dev_info(&drvdata->csdev->dev, "CTI initialized\n");
	return 0;

pm_release:
	cti_pm_release(drvdata);
	return ret;
}

static struct amba_cs_uci_id uci_id_cti[] = {
	{
		/*  CTI UCI data */
		.devarch	= 0x47701a14, /* CTI v2 */
		.devarch_mask	= 0xfff0ffff,
		.devtype	= 0x00000014, /* maj(0x4-debug) min(0x1-ECT) */
	}
};

static const struct amba_id cti_ids[] = {
	CS_AMBA_ID(0x000bb906), /* Coresight CTI (SoC 400), C-A72, C-A57 */
	CS_AMBA_ID(0x000bb922), /* CTI - C-A8 */
	CS_AMBA_ID(0x000bb9a8), /* CTI - C-A53 */
	CS_AMBA_ID(0x000bb9aa), /* CTI - C-A73 */
	CS_AMBA_UCI_ID(0x000bb9da, uci_id_cti), /* CTI - C-A35 */
	CS_AMBA_UCI_ID(0x000bb9ed, uci_id_cti), /* Coresight CTI (SoC 600) */
	{ 0, 0},
};

MODULE_DEVICE_TABLE(amba, cti_ids);

static struct amba_driver cti_driver = {
	.drv = {
		.name	= "coresight-cti",
		.owner = THIS_MODULE,
		.suppress_bind_attrs = true,
	},
	.probe		= cti_probe,
	.remove		= cti_remove,
	.id_table	= cti_ids,
};

static int __init cti_init(void)
{
	int ret;

	ret = amba_driver_register(&cti_driver);
	if (ret)
		pr_info("Error registering cti driver\n");
	coresight_set_cti_ops(&cti_assoc_ops);
	return ret;
}

static void __exit cti_exit(void)
{
	coresight_remove_cti_ops();
	amba_driver_unregister(&cti_driver);
}

module_init(cti_init);
module_exit(cti_exit);

MODULE_AUTHOR("Mike Leach <mike.leach@linaro.org>");
MODULE_DESCRIPTION("Arm CoreSight CTI Driver");
MODULE_LICENSE("GPL v2");