summaryrefslogtreecommitdiff
path: root/sound/soc/codecs/tas6424.c
blob: 63d2983c3fcf4dd64839f8f07d8caf8a0f46ca00 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * ALSA SoC Texas Instruments TAS6424 Quad-Channel Audio Amplifier
 *
 * Copyright (C) 2016-2017 Texas Instruments Incorporated - https://www.ti.com/
 *	Author: Andreas Dannenberg <dannenberg@ti.com>
 *	Andrew F. Davis <afd@ti.com>
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>

#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>
#include <sound/tlv.h>

#include "tas6424.h"

/* Define how often to check (and clear) the fault status register (in ms) */
#define TAS6424_FAULT_CHECK_INTERVAL 200

static const char * const tas6424_supply_names[] = {
	"dvdd", /* Digital power supply. Connect to 3.3-V supply. */
	"vbat", /* Supply used for higher voltage analog circuits. */
	"pvdd", /* Class-D amp output FETs supply. */
};
#define TAS6424_NUM_SUPPLIES ARRAY_SIZE(tas6424_supply_names)

struct tas6424_data {
	struct device *dev;
	struct regmap *regmap;
	struct regulator_bulk_data supplies[TAS6424_NUM_SUPPLIES];
	struct delayed_work fault_check_work;
	unsigned int last_cfault;
	unsigned int last_fault1;
	unsigned int last_fault2;
	unsigned int last_warn;
	struct gpio_desc *standby_gpio;
	struct gpio_desc *mute_gpio;
};

/*
 * DAC digital volumes. From -103.5 to 24 dB in 0.5 dB steps. Note that
 * setting the gain below -100 dB (register value <0x7) is effectively a MUTE
 * as per device datasheet.
 */
static DECLARE_TLV_DB_SCALE(dac_tlv, -10350, 50, 0);

static const struct snd_kcontrol_new tas6424_snd_controls[] = {
	SOC_SINGLE_TLV("Speaker Driver CH1 Playback Volume",
		       TAS6424_CH1_VOL_CTRL, 0, 0xff, 0, dac_tlv),
	SOC_SINGLE_TLV("Speaker Driver CH2 Playback Volume",
		       TAS6424_CH2_VOL_CTRL, 0, 0xff, 0, dac_tlv),
	SOC_SINGLE_TLV("Speaker Driver CH3 Playback Volume",
		       TAS6424_CH3_VOL_CTRL, 0, 0xff, 0, dac_tlv),
	SOC_SINGLE_TLV("Speaker Driver CH4 Playback Volume",
		       TAS6424_CH4_VOL_CTRL, 0, 0xff, 0, dac_tlv),
	SOC_SINGLE_STROBE("Auto Diagnostics Switch", TAS6424_DC_DIAG_CTRL1,
			  TAS6424_LDGBYPASS_SHIFT, 1),
};

static int tas6424_dac_event(struct snd_soc_dapm_widget *w,
			     struct snd_kcontrol *kcontrol, int event)
{
	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);

	dev_dbg(component->dev, "%s() event=0x%0x\n", __func__, event);

	if (event & SND_SOC_DAPM_POST_PMU) {
		/* Observe codec shutdown-to-active time */
		msleep(12);

		/* Turn on TAS6424 periodic fault checking/handling */
		tas6424->last_fault1 = 0;
		tas6424->last_fault2 = 0;
		tas6424->last_warn = 0;
		schedule_delayed_work(&tas6424->fault_check_work,
				      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
	} else if (event & SND_SOC_DAPM_PRE_PMD) {
		/* Disable TAS6424 periodic fault checking/handling */
		cancel_delayed_work_sync(&tas6424->fault_check_work);
	}

	return 0;
}

static const struct snd_soc_dapm_widget tas6424_dapm_widgets[] = {
	SND_SOC_DAPM_AIF_IN("DAC IN", "Playback", 0, SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_DAC_E("DAC", NULL, SND_SOC_NOPM, 0, 0, tas6424_dac_event,
			   SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
	SND_SOC_DAPM_OUTPUT("OUT")
};

static const struct snd_soc_dapm_route tas6424_audio_map[] = {
	{ "DAC", NULL, "DAC IN" },
	{ "OUT", NULL, "DAC" },
};

static int tas6424_hw_params(struct snd_pcm_substream *substream,
			     struct snd_pcm_hw_params *params,
			     struct snd_soc_dai *dai)
{
	struct snd_soc_component *component = dai->component;
	unsigned int rate = params_rate(params);
	unsigned int width = params_width(params);
	u8 sap_ctrl = 0;

	dev_dbg(component->dev, "%s() rate=%u width=%u\n", __func__, rate, width);

	switch (rate) {
	case 44100:
		sap_ctrl |= TAS6424_SAP_RATE_44100;
		break;
	case 48000:
		sap_ctrl |= TAS6424_SAP_RATE_48000;
		break;
	case 96000:
		sap_ctrl |= TAS6424_SAP_RATE_96000;
		break;
	default:
		dev_err(component->dev, "unsupported sample rate: %u\n", rate);
		return -EINVAL;
	}

	switch (width) {
	case 16:
		sap_ctrl |= TAS6424_SAP_TDM_SLOT_SZ_16;
		break;
	case 24:
		break;
	default:
		dev_err(component->dev, "unsupported sample width: %u\n", width);
		return -EINVAL;
	}

	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
			    TAS6424_SAP_RATE_MASK |
			    TAS6424_SAP_TDM_SLOT_SZ_16,
			    sap_ctrl);

	return 0;
}

static int tas6424_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
{
	struct snd_soc_component *component = dai->component;
	u8 serial_format = 0;

	dev_dbg(component->dev, "%s() fmt=0x%0x\n", __func__, fmt);

	/* clock masters */
	switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
	case SND_SOC_DAIFMT_CBC_CFC:
		break;
	default:
		dev_err(component->dev, "Invalid DAI clocking\n");
		return -EINVAL;
	}

	/* signal polarity */
	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		break;
	default:
		dev_err(component->dev, "Invalid DAI clock signal polarity\n");
		return -EINVAL;
	}

	/* interface format */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		serial_format |= TAS6424_SAP_I2S;
		break;
	case SND_SOC_DAIFMT_DSP_A:
		serial_format |= TAS6424_SAP_DSP;
		break;
	case SND_SOC_DAIFMT_DSP_B:
		/*
		 * We can use the fact that the TAS6424 does not care about the
		 * LRCLK duty cycle during TDM to receive DSP_B formatted data
		 * in LEFTJ mode (no delaying of the 1st data bit).
		 */
		serial_format |= TAS6424_SAP_LEFTJ;
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		serial_format |= TAS6424_SAP_LEFTJ;
		break;
	default:
		dev_err(component->dev, "Invalid DAI interface format\n");
		return -EINVAL;
	}

	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL,
			    TAS6424_SAP_FMT_MASK, serial_format);

	return 0;
}

static int tas6424_set_dai_tdm_slot(struct snd_soc_dai *dai,
				    unsigned int tx_mask, unsigned int rx_mask,
				    int slots, int slot_width)
{
	struct snd_soc_component *component = dai->component;
	unsigned int first_slot, last_slot;
	bool sap_tdm_slot_last;

	dev_dbg(component->dev, "%s() tx_mask=%d rx_mask=%d\n", __func__,
		tx_mask, rx_mask);

	if (!tx_mask || !rx_mask)
		return 0; /* nothing needed to disable TDM mode */

	/*
	 * Determine the first slot and last slot that is being requested so
	 * we'll be able to more easily enforce certain constraints as the
	 * TAS6424's TDM interface is not fully configurable.
	 */
	first_slot = __ffs(tx_mask);
	last_slot = __fls(rx_mask);

	if (last_slot - first_slot != 4) {
		dev_err(component->dev, "tdm mask must cover 4 contiguous slots\n");
		return -EINVAL;
	}

	switch (first_slot) {
	case 0:
		sap_tdm_slot_last = false;
		break;
	case 4:
		sap_tdm_slot_last = true;
		break;
	default:
		dev_err(component->dev, "tdm mask must start at slot 0 or 4\n");
		return -EINVAL;
	}

	snd_soc_component_update_bits(component, TAS6424_SAP_CTRL, TAS6424_SAP_TDM_SLOT_LAST,
			    sap_tdm_slot_last ? TAS6424_SAP_TDM_SLOT_LAST : 0);

	return 0;
}

static int tas6424_mute(struct snd_soc_dai *dai, int mute, int direction)
{
	struct snd_soc_component *component = dai->component;
	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
	unsigned int val;

	dev_dbg(component->dev, "%s() mute=%d\n", __func__, mute);

	if (tas6424->mute_gpio) {
		gpiod_set_value_cansleep(tas6424->mute_gpio, mute);
		return 0;
	}

	if (mute)
		val = TAS6424_ALL_STATE_MUTE;
	else
		val = TAS6424_ALL_STATE_PLAY;

	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, val);

	return 0;
}

static int tas6424_power_off(struct snd_soc_component *component)
{
	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
	int ret;

	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, TAS6424_ALL_STATE_HIZ);

	regcache_cache_only(tas6424->regmap, true);
	regcache_mark_dirty(tas6424->regmap);

	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
				     tas6424->supplies);
	if (ret < 0) {
		dev_err(component->dev, "failed to disable supplies: %d\n", ret);
		return ret;
	}

	return 0;
}

static int tas6424_power_on(struct snd_soc_component *component)
{
	struct tas6424_data *tas6424 = snd_soc_component_get_drvdata(component);
	int ret;
	u8 chan_states;
	int no_auto_diags = 0;
	unsigned int reg_val;

	if (!regmap_read(tas6424->regmap, TAS6424_DC_DIAG_CTRL1, &reg_val))
		no_auto_diags = reg_val & TAS6424_LDGBYPASS_MASK;

	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
				    tas6424->supplies);
	if (ret < 0) {
		dev_err(component->dev, "failed to enable supplies: %d\n", ret);
		return ret;
	}

	regcache_cache_only(tas6424->regmap, false);

	ret = regcache_sync(tas6424->regmap);
	if (ret < 0) {
		dev_err(component->dev, "failed to sync regcache: %d\n", ret);
		return ret;
	}

	if (tas6424->mute_gpio) {
		gpiod_set_value_cansleep(tas6424->mute_gpio, 0);
		/*
		 * channels are muted via the mute pin.  Don't also mute
		 * them via the registers so that subsequent register
		 * access is not necessary to un-mute the channels
		 */
		chan_states = TAS6424_ALL_STATE_PLAY;
	} else {
		chan_states = TAS6424_ALL_STATE_MUTE;
	}
	snd_soc_component_write(component, TAS6424_CH_STATE_CTRL, chan_states);

	/* any time we come out of HIZ, the output channels automatically run DC
	 * load diagnostics if autodiagnotics are enabled. wait here until this
	 * completes.
	 */
	if (!no_auto_diags)
		msleep(230);

	return 0;
}

static int tas6424_set_bias_level(struct snd_soc_component *component,
				  enum snd_soc_bias_level level)
{
	dev_dbg(component->dev, "%s() level=%d\n", __func__, level);

	switch (level) {
	case SND_SOC_BIAS_ON:
	case SND_SOC_BIAS_PREPARE:
		break;
	case SND_SOC_BIAS_STANDBY:
		if (snd_soc_component_get_bias_level(component) == SND_SOC_BIAS_OFF)
			tas6424_power_on(component);
		break;
	case SND_SOC_BIAS_OFF:
		tas6424_power_off(component);
		break;
	}

	return 0;
}

static struct snd_soc_component_driver soc_codec_dev_tas6424 = {
	.set_bias_level		= tas6424_set_bias_level,
	.controls		= tas6424_snd_controls,
	.num_controls		= ARRAY_SIZE(tas6424_snd_controls),
	.dapm_widgets		= tas6424_dapm_widgets,
	.num_dapm_widgets	= ARRAY_SIZE(tas6424_dapm_widgets),
	.dapm_routes		= tas6424_audio_map,
	.num_dapm_routes	= ARRAY_SIZE(tas6424_audio_map),
	.use_pmdown_time	= 1,
	.endianness		= 1,
};

static const struct snd_soc_dai_ops tas6424_speaker_dai_ops = {
	.hw_params	= tas6424_hw_params,
	.set_fmt	= tas6424_set_dai_fmt,
	.set_tdm_slot	= tas6424_set_dai_tdm_slot,
	.mute_stream	= tas6424_mute,
	.no_capture_mute = 1,
};

static struct snd_soc_dai_driver tas6424_dai[] = {
	{
		.name = "tas6424-amplifier",
		.playback = {
			.stream_name = "Playback",
			.channels_min = 1,
			.channels_max = 4,
			.rates = TAS6424_RATES,
			.formats = TAS6424_FORMATS,
		},
		.ops = &tas6424_speaker_dai_ops,
	},
};

static void tas6424_fault_check_work(struct work_struct *work)
{
	struct tas6424_data *tas6424 = container_of(work, struct tas6424_data,
						    fault_check_work.work);
	struct device *dev = tas6424->dev;
	unsigned int reg;
	int ret;

	ret = regmap_read(tas6424->regmap, TAS6424_CHANNEL_FAULT, &reg);
	if (ret < 0) {
		dev_err(dev, "failed to read CHANNEL_FAULT register: %d\n", ret);
		goto out;
	}

	if (!reg) {
		tas6424->last_cfault = reg;
		goto check_global_fault1_reg;
	}

	/*
	 * Only flag errors once for a given occurrence. This is needed as
	 * the TAS6424 will take time clearing the fault condition internally
	 * during which we don't want to bombard the system with the same
	 * error message over and over.
	 */
	if ((reg & TAS6424_FAULT_OC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH1))
		dev_crit(dev, "experienced a channel 1 overcurrent fault\n");

	if ((reg & TAS6424_FAULT_OC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH2))
		dev_crit(dev, "experienced a channel 2 overcurrent fault\n");

	if ((reg & TAS6424_FAULT_OC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH3))
		dev_crit(dev, "experienced a channel 3 overcurrent fault\n");

	if ((reg & TAS6424_FAULT_OC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_OC_CH4))
		dev_crit(dev, "experienced a channel 4 overcurrent fault\n");

	if ((reg & TAS6424_FAULT_DC_CH1) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH1))
		dev_crit(dev, "experienced a channel 1 DC fault\n");

	if ((reg & TAS6424_FAULT_DC_CH2) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH2))
		dev_crit(dev, "experienced a channel 2 DC fault\n");

	if ((reg & TAS6424_FAULT_DC_CH3) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH3))
		dev_crit(dev, "experienced a channel 3 DC fault\n");

	if ((reg & TAS6424_FAULT_DC_CH4) && !(tas6424->last_cfault & TAS6424_FAULT_DC_CH4))
		dev_crit(dev, "experienced a channel 4 DC fault\n");

	/* Store current fault1 value so we can detect any changes next time */
	tas6424->last_cfault = reg;

check_global_fault1_reg:
	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT1, &reg);
	if (ret < 0) {
		dev_err(dev, "failed to read GLOB_FAULT1 register: %d\n", ret);
		goto out;
	}

	/*
	 * Ignore any clock faults as there is no clean way to check for them.
	 * We would need to start checking for those faults *after* the SAIF
	 * stream has been setup, and stop checking *before* the stream is
	 * stopped to avoid any false-positives. However there are no
	 * appropriate hooks to monitor these events.
	 */
	reg &= TAS6424_FAULT_PVDD_OV |
	       TAS6424_FAULT_VBAT_OV |
	       TAS6424_FAULT_PVDD_UV |
	       TAS6424_FAULT_VBAT_UV;

	if (!reg) {
		tas6424->last_fault1 = reg;
		goto check_global_fault2_reg;
	}

	if ((reg & TAS6424_FAULT_PVDD_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_OV))
		dev_crit(dev, "experienced a PVDD overvoltage fault\n");

	if ((reg & TAS6424_FAULT_VBAT_OV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_OV))
		dev_crit(dev, "experienced a VBAT overvoltage fault\n");

	if ((reg & TAS6424_FAULT_PVDD_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_PVDD_UV))
		dev_crit(dev, "experienced a PVDD undervoltage fault\n");

	if ((reg & TAS6424_FAULT_VBAT_UV) && !(tas6424->last_fault1 & TAS6424_FAULT_VBAT_UV))
		dev_crit(dev, "experienced a VBAT undervoltage fault\n");

	/* Store current fault1 value so we can detect any changes next time */
	tas6424->last_fault1 = reg;

check_global_fault2_reg:
	ret = regmap_read(tas6424->regmap, TAS6424_GLOB_FAULT2, &reg);
	if (ret < 0) {
		dev_err(dev, "failed to read GLOB_FAULT2 register: %d\n", ret);
		goto out;
	}

	reg &= TAS6424_FAULT_OTSD |
	       TAS6424_FAULT_OTSD_CH1 |
	       TAS6424_FAULT_OTSD_CH2 |
	       TAS6424_FAULT_OTSD_CH3 |
	       TAS6424_FAULT_OTSD_CH4;

	if (!reg) {
		tas6424->last_fault2 = reg;
		goto check_warn_reg;
	}

	if ((reg & TAS6424_FAULT_OTSD) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD))
		dev_crit(dev, "experienced a global overtemp shutdown\n");

	if ((reg & TAS6424_FAULT_OTSD_CH1) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH1))
		dev_crit(dev, "experienced an overtemp shutdown on CH1\n");

	if ((reg & TAS6424_FAULT_OTSD_CH2) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH2))
		dev_crit(dev, "experienced an overtemp shutdown on CH2\n");

	if ((reg & TAS6424_FAULT_OTSD_CH3) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH3))
		dev_crit(dev, "experienced an overtemp shutdown on CH3\n");

	if ((reg & TAS6424_FAULT_OTSD_CH4) && !(tas6424->last_fault2 & TAS6424_FAULT_OTSD_CH4))
		dev_crit(dev, "experienced an overtemp shutdown on CH4\n");

	/* Store current fault2 value so we can detect any changes next time */
	tas6424->last_fault2 = reg;

check_warn_reg:
	ret = regmap_read(tas6424->regmap, TAS6424_WARN, &reg);
	if (ret < 0) {
		dev_err(dev, "failed to read WARN register: %d\n", ret);
		goto out;
	}

	reg &= TAS6424_WARN_VDD_UV |
	       TAS6424_WARN_VDD_POR |
	       TAS6424_WARN_VDD_OTW |
	       TAS6424_WARN_VDD_OTW_CH1 |
	       TAS6424_WARN_VDD_OTW_CH2 |
	       TAS6424_WARN_VDD_OTW_CH3 |
	       TAS6424_WARN_VDD_OTW_CH4;

	if (!reg) {
		tas6424->last_warn = reg;
		goto out;
	}

	if ((reg & TAS6424_WARN_VDD_UV) && !(tas6424->last_warn & TAS6424_WARN_VDD_UV))
		dev_warn(dev, "experienced a VDD under voltage condition\n");

	if ((reg & TAS6424_WARN_VDD_POR) && !(tas6424->last_warn & TAS6424_WARN_VDD_POR))
		dev_warn(dev, "experienced a VDD POR condition\n");

	if ((reg & TAS6424_WARN_VDD_OTW) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW))
		dev_warn(dev, "experienced a global overtemp warning\n");

	if ((reg & TAS6424_WARN_VDD_OTW_CH1) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH1))
		dev_warn(dev, "experienced an overtemp warning on CH1\n");

	if ((reg & TAS6424_WARN_VDD_OTW_CH2) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH2))
		dev_warn(dev, "experienced an overtemp warning on CH2\n");

	if ((reg & TAS6424_WARN_VDD_OTW_CH3) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH3))
		dev_warn(dev, "experienced an overtemp warning on CH3\n");

	if ((reg & TAS6424_WARN_VDD_OTW_CH4) && !(tas6424->last_warn & TAS6424_WARN_VDD_OTW_CH4))
		dev_warn(dev, "experienced an overtemp warning on CH4\n");

	/* Store current warn value so we can detect any changes next time */
	tas6424->last_warn = reg;

	/* Clear any warnings by toggling the CLEAR_FAULT control bit */
	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
				TAS6424_CLEAR_FAULT, TAS6424_CLEAR_FAULT);
	if (ret < 0)
		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);

	ret = regmap_write_bits(tas6424->regmap, TAS6424_MISC_CTRL3,
				TAS6424_CLEAR_FAULT, 0);
	if (ret < 0)
		dev_err(dev, "failed to write MISC_CTRL3 register: %d\n", ret);

out:
	/* Schedule the next fault check at the specified interval */
	schedule_delayed_work(&tas6424->fault_check_work,
			      msecs_to_jiffies(TAS6424_FAULT_CHECK_INTERVAL));
}

static const struct reg_default tas6424_reg_defaults[] = {
	{ TAS6424_MODE_CTRL,		0x00 },
	{ TAS6424_MISC_CTRL1,		0x32 },
	{ TAS6424_MISC_CTRL2,		0x62 },
	{ TAS6424_SAP_CTRL,		0x04 },
	{ TAS6424_CH_STATE_CTRL,	0x55 },
	{ TAS6424_CH1_VOL_CTRL,		0xcf },
	{ TAS6424_CH2_VOL_CTRL,		0xcf },
	{ TAS6424_CH3_VOL_CTRL,		0xcf },
	{ TAS6424_CH4_VOL_CTRL,		0xcf },
	{ TAS6424_DC_DIAG_CTRL1,	0x00 },
	{ TAS6424_DC_DIAG_CTRL2,	0x11 },
	{ TAS6424_DC_DIAG_CTRL3,	0x11 },
	{ TAS6424_PIN_CTRL,		0xff },
	{ TAS6424_AC_DIAG_CTRL1,	0x00 },
	{ TAS6424_MISC_CTRL3,		0x00 },
	{ TAS6424_CLIP_CTRL,		0x01 },
	{ TAS6424_CLIP_WINDOW,		0x14 },
	{ TAS6424_CLIP_WARN,		0x00 },
	{ TAS6424_CBC_STAT,		0x00 },
	{ TAS6424_MISC_CTRL4,		0x40 },
};

static bool tas6424_is_writable_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case TAS6424_MODE_CTRL:
	case TAS6424_MISC_CTRL1:
	case TAS6424_MISC_CTRL2:
	case TAS6424_SAP_CTRL:
	case TAS6424_CH_STATE_CTRL:
	case TAS6424_CH1_VOL_CTRL:
	case TAS6424_CH2_VOL_CTRL:
	case TAS6424_CH3_VOL_CTRL:
	case TAS6424_CH4_VOL_CTRL:
	case TAS6424_DC_DIAG_CTRL1:
	case TAS6424_DC_DIAG_CTRL2:
	case TAS6424_DC_DIAG_CTRL3:
	case TAS6424_PIN_CTRL:
	case TAS6424_AC_DIAG_CTRL1:
	case TAS6424_MISC_CTRL3:
	case TAS6424_CLIP_CTRL:
	case TAS6424_CLIP_WINDOW:
	case TAS6424_CLIP_WARN:
	case TAS6424_CBC_STAT:
	case TAS6424_MISC_CTRL4:
		return true;
	default:
		return false;
	}
}

static bool tas6424_is_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case TAS6424_DC_LOAD_DIAG_REP12:
	case TAS6424_DC_LOAD_DIAG_REP34:
	case TAS6424_DC_LOAD_DIAG_REPLO:
	case TAS6424_CHANNEL_STATE:
	case TAS6424_CHANNEL_FAULT:
	case TAS6424_GLOB_FAULT1:
	case TAS6424_GLOB_FAULT2:
	case TAS6424_WARN:
	case TAS6424_AC_LOAD_DIAG_REP1:
	case TAS6424_AC_LOAD_DIAG_REP2:
	case TAS6424_AC_LOAD_DIAG_REP3:
	case TAS6424_AC_LOAD_DIAG_REP4:
		return true;
	default:
		return false;
	}
}

static const struct regmap_config tas6424_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.writeable_reg = tas6424_is_writable_reg,
	.volatile_reg = tas6424_is_volatile_reg,

	.max_register = TAS6424_MAX,
	.reg_defaults = tas6424_reg_defaults,
	.num_reg_defaults = ARRAY_SIZE(tas6424_reg_defaults),
	.cache_type = REGCACHE_RBTREE,
};

#if IS_ENABLED(CONFIG_OF)
static const struct of_device_id tas6424_of_ids[] = {
	{ .compatible = "ti,tas6424", },
	{ },
};
MODULE_DEVICE_TABLE(of, tas6424_of_ids);
#endif

static int tas6424_i2c_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct tas6424_data *tas6424;
	int ret;
	int i;

	tas6424 = devm_kzalloc(dev, sizeof(*tas6424), GFP_KERNEL);
	if (!tas6424)
		return -ENOMEM;
	dev_set_drvdata(dev, tas6424);

	tas6424->dev = dev;

	tas6424->regmap = devm_regmap_init_i2c(client, &tas6424_regmap_config);
	if (IS_ERR(tas6424->regmap)) {
		ret = PTR_ERR(tas6424->regmap);
		dev_err(dev, "unable to allocate register map: %d\n", ret);
		return ret;
	}

	/*
	 * Get control of the standby pin and set it LOW to take the codec
	 * out of the stand-by mode.
	 * Note: The actual pin polarity is taken care of in the GPIO lib
	 * according the polarity specified in the DTS.
	 */
	tas6424->standby_gpio = devm_gpiod_get_optional(dev, "standby",
						      GPIOD_OUT_LOW);
	if (IS_ERR(tas6424->standby_gpio)) {
		if (PTR_ERR(tas6424->standby_gpio) == -EPROBE_DEFER)
			return -EPROBE_DEFER;
		dev_info(dev, "failed to get standby GPIO: %ld\n",
			PTR_ERR(tas6424->standby_gpio));
		tas6424->standby_gpio = NULL;
	}

	/*
	 * Get control of the mute pin and set it HIGH in order to start with
	 * all the output muted.
	 * Note: The actual pin polarity is taken care of in the GPIO lib
	 * according the polarity specified in the DTS.
	 */
	tas6424->mute_gpio = devm_gpiod_get_optional(dev, "mute",
						      GPIOD_OUT_HIGH);
	if (IS_ERR(tas6424->mute_gpio)) {
		if (PTR_ERR(tas6424->mute_gpio) == -EPROBE_DEFER)
			return -EPROBE_DEFER;
		dev_info(dev, "failed to get nmute GPIO: %ld\n",
			PTR_ERR(tas6424->mute_gpio));
		tas6424->mute_gpio = NULL;
	}

	for (i = 0; i < ARRAY_SIZE(tas6424->supplies); i++)
		tas6424->supplies[i].supply = tas6424_supply_names[i];
	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(tas6424->supplies),
				      tas6424->supplies);
	if (ret) {
		dev_err(dev, "unable to request supplies: %d\n", ret);
		return ret;
	}

	ret = regulator_bulk_enable(ARRAY_SIZE(tas6424->supplies),
				    tas6424->supplies);
	if (ret) {
		dev_err(dev, "unable to enable supplies: %d\n", ret);
		return ret;
	}

	/* Reset device to establish well-defined startup state */
	ret = regmap_update_bits(tas6424->regmap, TAS6424_MODE_CTRL,
				 TAS6424_RESET, TAS6424_RESET);
	if (ret) {
		dev_err(dev, "unable to reset device: %d\n", ret);
		goto disable_regs;
	}

	INIT_DELAYED_WORK(&tas6424->fault_check_work, tas6424_fault_check_work);

	ret = devm_snd_soc_register_component(dev, &soc_codec_dev_tas6424,
				     tas6424_dai, ARRAY_SIZE(tas6424_dai));
	if (ret < 0) {
		dev_err(dev, "unable to register codec: %d\n", ret);
		goto disable_regs;
	}

	return 0;

disable_regs:
	regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies), tas6424->supplies);
	return ret;
}

static int tas6424_i2c_remove(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct tas6424_data *tas6424 = dev_get_drvdata(dev);
	int ret;

	cancel_delayed_work_sync(&tas6424->fault_check_work);

	/* put the codec in stand-by */
	if (tas6424->standby_gpio)
		gpiod_set_value_cansleep(tas6424->standby_gpio, 1);

	ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies),
				     tas6424->supplies);
	if (ret < 0)
		dev_err(dev, "unable to disable supplies: %d\n", ret);

	return 0;
}

static const struct i2c_device_id tas6424_i2c_ids[] = {
	{ "tas6424", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tas6424_i2c_ids);

static struct i2c_driver tas6424_i2c_driver = {
	.driver = {
		.name = "tas6424",
		.of_match_table = of_match_ptr(tas6424_of_ids),
	},
	.probe_new = tas6424_i2c_probe,
	.remove = tas6424_i2c_remove,
	.id_table = tas6424_i2c_ids,
};
module_i2c_driver(tas6424_i2c_driver);

MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("TAS6424 Audio amplifier driver");
MODULE_LICENSE("GPL v2");