aboutsummaryrefslogtreecommitdiffstats
path: root/sound/soc/codecs/wm8804.c
blob: 1bd4ace295948a4851132e9f75d3e3c12529ea9c (plain) (blame)
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
/*
 * wm8804.c  --  WM8804 S/PDIF transceiver driver
 *
 * Copyright 2010-11 Wolfson Microelectronics plc
 *
 * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.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/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/of_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/initval.h>
#include <sound/tlv.h>

#include "wm8804.h"

#define WM8804_NUM_SUPPLIES 2
static const char *wm8804_supply_names[WM8804_NUM_SUPPLIES] = {
	"PVDD",
	"DVDD"
};

static const struct reg_default wm8804_reg_defaults[] = {
	{ 3,  0x21 },     /* R3  - PLL1 */
	{ 4,  0xFD },     /* R4  - PLL2 */
	{ 5,  0x36 },     /* R5  - PLL3 */
	{ 6,  0x07 },     /* R6  - PLL4 */
	{ 7,  0x16 },     /* R7  - PLL5 */
	{ 8,  0x18 },     /* R8  - PLL6 */
	{ 9,  0xFF },     /* R9  - SPDMODE */
	{ 10, 0x00 },     /* R10 - INTMASK */
	{ 18, 0x00 },     /* R18 - SPDTX1 */
	{ 19, 0x00 },     /* R19 - SPDTX2 */
	{ 20, 0x00 },     /* R20 - SPDTX3 */
	{ 21, 0x71 },     /* R21 - SPDTX4 */
	{ 22, 0x0B },     /* R22 - SPDTX5 */
	{ 23, 0x70 },     /* R23 - GPO0 */
	{ 24, 0x57 },     /* R24 - GPO1 */
	{ 26, 0x42 },     /* R26 - GPO2 */
	{ 27, 0x06 },     /* R27 - AIFTX */
	{ 28, 0x06 },     /* R28 - AIFRX */
	{ 29, 0x80 },     /* R29 - SPDRX1 */
	{ 30, 0x07 },     /* R30 - PWRDN */
};

struct wm8804_priv {
	struct regmap *regmap;
	struct regulator_bulk_data supplies[WM8804_NUM_SUPPLIES];
	struct notifier_block disable_nb[WM8804_NUM_SUPPLIES];
	int mclk_div;
};

static int txsrc_get(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol);

static int txsrc_put(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol);

/*
 * We can't use the same notifier block for more than one supply and
 * there's no way I can see to get from a callback to the caller
 * except container_of().
 */
#define WM8804_REGULATOR_EVENT(n) \
static int wm8804_regulator_event_##n(struct notifier_block *nb, \
				      unsigned long event, void *data)    \
{ \
	struct wm8804_priv *wm8804 = container_of(nb, struct wm8804_priv, \
						  disable_nb[n]); \
	if (event & REGULATOR_EVENT_DISABLE) { \
		regcache_mark_dirty(wm8804->regmap);	\
	} \
	return 0; \
}

WM8804_REGULATOR_EVENT(0)
WM8804_REGULATOR_EVENT(1)

static const char *txsrc_text[] = { "S/PDIF RX", "AIF" };
static SOC_ENUM_SINGLE_EXT_DECL(txsrc, txsrc_text);

static const struct snd_kcontrol_new wm8804_snd_controls[] = {
	SOC_ENUM_EXT("Input Source", txsrc, txsrc_get, txsrc_put),
	SOC_SINGLE("TX Playback Switch", WM8804_PWRDN, 2, 1, 1),
	SOC_SINGLE("AIF Playback Switch", WM8804_PWRDN, 4, 1, 1)
};

static int txsrc_get(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct snd_soc_codec *codec;
	unsigned int src;

	codec = snd_soc_kcontrol_codec(kcontrol);
	src = snd_soc_read(codec, WM8804_SPDTX4);
	if (src & 0x40)
		ucontrol->value.integer.value[0] = 1;
	else
		ucontrol->value.integer.value[0] = 0;

	return 0;
}

static int txsrc_put(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct snd_soc_codec *codec;
	unsigned int src, txpwr;

	codec = snd_soc_kcontrol_codec(kcontrol);

	if (ucontrol->value.integer.value[0] != 0
			&& ucontrol->value.integer.value[0] != 1)
		return -EINVAL;

	src = snd_soc_read(codec, WM8804_SPDTX4);
	switch ((src & 0x40) >> 6) {
	case 0:
		if (!ucontrol->value.integer.value[0])
			return 0;
		break;
	case 1:
		if (ucontrol->value.integer.value[1])
			return 0;
		break;
	}

	/* save the current power state of the transmitter */
	txpwr = snd_soc_read(codec, WM8804_PWRDN) & 0x4;
	/* power down the transmitter */
	snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, 0x4);
	/* set the tx source */
	snd_soc_update_bits(codec, WM8804_SPDTX4, 0x40,
			    ucontrol->value.integer.value[0] << 6);

	if (ucontrol->value.integer.value[0]) {
		/* power down the receiver */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x2, 0x2);
		/* power up the AIF */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x10, 0);
	} else {
		/* don't power down the AIF -- may be used as an output */
		/* power up the receiver */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x2, 0);
	}

	/* restore the transmitter's configuration */
	snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, txpwr);

	return 0;
}

static bool wm8804_volatile(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case WM8804_RST_DEVID1:
	case WM8804_DEVID2:
	case WM8804_DEVREV:
	case WM8804_INTSTAT:
	case WM8804_SPDSTAT:
	case WM8804_RXCHAN1:
	case WM8804_RXCHAN2:
	case WM8804_RXCHAN3:
	case WM8804_RXCHAN4:
	case WM8804_RXCHAN5:
		return true;
	default:
		return false;
	}
}

static int wm8804_reset(struct wm8804_priv *wm8804)
{
	return regmap_write(wm8804->regmap, WM8804_RST_DEVID1, 0x0);
}

static int wm8804_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
{
	struct snd_soc_codec *codec;
	u16 format, master, bcp, lrp;

	codec = dai->codec;

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		format = 0x2;
		break;
	case SND_SOC_DAIFMT_RIGHT_J:
		format = 0x0;
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		format = 0x1;
		break;
	case SND_SOC_DAIFMT_DSP_A:
	case SND_SOC_DAIFMT_DSP_B:
		format = 0x3;
		break;
	default:
		dev_err(dai->dev, "Unknown dai format\n");
		return -EINVAL;
	}

	/* set data format */
	snd_soc_update_bits(codec, WM8804_AIFTX, 0x3, format);
	snd_soc_update_bits(codec, WM8804_AIFRX, 0x3, format);

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
		master = 1;
		break;
	case SND_SOC_DAIFMT_CBS_CFS:
		master = 0;
		break;
	default:
		dev_err(dai->dev, "Unknown master/slave configuration\n");
		return -EINVAL;
	}

	/* set master/slave mode */
	snd_soc_update_bits(codec, WM8804_AIFRX, 0x40, master << 6);

	bcp = lrp = 0;
	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		break;
	case SND_SOC_DAIFMT_IB_IF:
		bcp = lrp = 1;
		break;
	case SND_SOC_DAIFMT_IB_NF:
		bcp = 1;
		break;
	case SND_SOC_DAIFMT_NB_IF:
		lrp = 1;
		break;
	default:
		dev_err(dai->dev, "Unknown polarity configuration\n");
		return -EINVAL;
	}

	/* set frame inversion */
	snd_soc_update_bits(codec, WM8804_AIFTX, 0x10 | 0x20,
			    (bcp << 4) | (lrp << 5));
	snd_soc_update_bits(codec, WM8804_AIFRX, 0x10 | 0x20,
			    (bcp << 4) | (lrp << 5));
	return 0;
}

static int wm8804_hw_params(struct snd_pcm_substream *substream,
			    struct snd_pcm_hw_params *params,
			    struct snd_soc_dai *dai)
{
	struct snd_soc_codec *codec;
	u16 blen;

	codec = dai->codec;

	switch (params_width(params)) {
	case 16:
		blen = 0x0;
		break;
	case 20:
		blen = 0x1;
		break;
	case 24:
		blen = 0x2;
		break;
	default:
		dev_err(dai->dev, "Unsupported word length: %u\n",
			params_width(params));
		return -EINVAL;
	}

	/* set word length */
	snd_soc_update_bits(codec, WM8804_AIFTX, 0xc, blen << 2);
	snd_soc_update_bits(codec, WM8804_AIFRX, 0xc, blen << 2);

	return 0;
}

struct pll_div {
	u32 prescale:1;
	u32 mclkdiv:1;
	u32 freqmode:2;
	u32 n:4;
	u32 k:22;
};

/* PLL rate to output rate divisions */
static struct {
	unsigned int div;
	unsigned int freqmode;
	unsigned int mclkdiv;
} post_table[] = {
	{  2,  0, 0 },
	{  4,  0, 1 },
	{  4,  1, 0 },
	{  8,  1, 1 },
	{  8,  2, 0 },
	{ 16,  2, 1 },
	{ 12,  3, 0 },
	{ 24,  3, 1 }
};

#define FIXED_PLL_SIZE ((1ULL << 22) * 10)
static int pll_factors(struct pll_div *pll_div, unsigned int target,
		       unsigned int source, unsigned int mclk_div)
{
	u64 Kpart;
	unsigned long int K, Ndiv, Nmod, tmp;
	int i;

	/*
	 * Scale the output frequency up; the PLL should run in the
	 * region of 90-100MHz.
	 */
	for (i = 0; i < ARRAY_SIZE(post_table); i++) {
		tmp = target * post_table[i].div;
		if ((tmp >= 90000000 && tmp <= 100000000) &&
		    (mclk_div == post_table[i].mclkdiv)) {
			pll_div->freqmode = post_table[i].freqmode;
			pll_div->mclkdiv = post_table[i].mclkdiv;
			target *= post_table[i].div;
			break;
		}
	}

	if (i == ARRAY_SIZE(post_table)) {
		pr_err("%s: Unable to scale output frequency: %uHz\n",
		       __func__, target);
		return -EINVAL;
	}

	pll_div->prescale = 0;
	Ndiv = target / source;
	if (Ndiv < 5) {
		source >>= 1;
		pll_div->prescale = 1;
		Ndiv = target / source;
	}

	if (Ndiv < 5 || Ndiv > 13) {
		pr_err("%s: WM8804 N value is not within the recommended range: %lu\n",
		       __func__, Ndiv);
		return -EINVAL;
	}
	pll_div->n = Ndiv;

	Nmod = target % source;
	Kpart = FIXED_PLL_SIZE * (u64)Nmod;

	do_div(Kpart, source);

	K = Kpart & 0xffffffff;
	if ((K % 10) >= 5)
		K += 5;
	K /= 10;
	pll_div->k = K;

	return 0;
}

static int wm8804_set_pll(struct snd_soc_dai *dai, int pll_id,
			  int source, unsigned int freq_in,
			  unsigned int freq_out)
{
	struct snd_soc_codec *codec;

	codec = dai->codec;
	if (!freq_in || !freq_out) {
		/* disable the PLL */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x1, 0x1);
		return 0;
	} else {
		int ret;
		struct pll_div pll_div;
		struct wm8804_priv *wm8804;

		wm8804 = snd_soc_codec_get_drvdata(codec);

		ret = pll_factors(&pll_div, freq_out, freq_in,
				  wm8804->mclk_div);
		if (ret)
			return ret;

		/* power down the PLL before reprogramming it */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x1, 0x1);

		/* set PLLN and PRESCALE */
		snd_soc_update_bits(codec, WM8804_PLL4, 0xf | 0x10,
				    pll_div.n | (pll_div.prescale << 4));
		/* set mclkdiv and freqmode */
		snd_soc_update_bits(codec, WM8804_PLL5, 0x3 | 0x8,
				    pll_div.freqmode | (pll_div.mclkdiv << 3));
		/* set PLLK */
		snd_soc_write(codec, WM8804_PLL1, pll_div.k & 0xff);
		snd_soc_write(codec, WM8804_PLL2, (pll_div.k >> 8) & 0xff);
		snd_soc_write(codec, WM8804_PLL3, pll_div.k >> 16);

		/* power up the PLL */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x1, 0);
	}

	return 0;
}

static int wm8804_set_sysclk(struct snd_soc_dai *dai,
			     int clk_id, unsigned int freq, int dir)
{
	struct snd_soc_codec *codec;

	codec = dai->codec;

	switch (clk_id) {
	case WM8804_TX_CLKSRC_MCLK:
		if ((freq >= 10000000 && freq <= 14400000)
				|| (freq >= 16280000 && freq <= 27000000))
			snd_soc_update_bits(codec, WM8804_PLL6, 0x80, 0x80);
		else {
			dev_err(dai->dev, "OSCCLOCK is not within the "
				"recommended range: %uHz\n", freq);
			return -EINVAL;
		}
		break;
	case WM8804_TX_CLKSRC_PLL:
		snd_soc_update_bits(codec, WM8804_PLL6, 0x80, 0);
		break;
	case WM8804_CLKOUT_SRC_CLK1:
		snd_soc_update_bits(codec, WM8804_PLL6, 0x8, 0);
		break;
	case WM8804_CLKOUT_SRC_OSCCLK:
		snd_soc_update_bits(codec, WM8804_PLL6, 0x8, 0x8);
		break;
	default:
		dev_err(dai->dev, "Unknown clock source: %d\n", clk_id);
		return -EINVAL;
	}

	return 0;
}

static int wm8804_set_clkdiv(struct snd_soc_dai *dai,
			     int div_id, int div)
{
	struct snd_soc_codec *codec;
	struct wm8804_priv *wm8804;

	codec = dai->codec;
	switch (div_id) {
	case WM8804_CLKOUT_DIV:
		snd_soc_update_bits(codec, WM8804_PLL5, 0x30,
				    (div & 0x3) << 4);
		break;
	case WM8804_MCLK_DIV:
		wm8804 = snd_soc_codec_get_drvdata(codec);
		wm8804->mclk_div = div;
		break;
	default:
		dev_err(dai->dev, "Unknown clock divider: %d\n", div_id);
		return -EINVAL;
	}
	return 0;
}

static int wm8804_set_bias_level(struct snd_soc_codec *codec,
				 enum snd_soc_bias_level level)
{
	int ret;
	struct wm8804_priv *wm8804;

	wm8804 = snd_soc_codec_get_drvdata(codec);
	switch (level) {
	case SND_SOC_BIAS_ON:
		break;
	case SND_SOC_BIAS_PREPARE:
		/* power up the OSC and the PLL */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x9, 0);
		break;
	case SND_SOC_BIAS_STANDBY:
		if (codec->dapm.bias_level == SND_SOC_BIAS_OFF) {
			ret = regulator_bulk_enable(ARRAY_SIZE(wm8804->supplies),
						    wm8804->supplies);
			if (ret) {
				dev_err(codec->dev,
					"Failed to enable supplies: %d\n",
					ret);
				return ret;
			}
			regcache_sync(wm8804->regmap);
		}
		/* power down the OSC and the PLL */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x9, 0x9);
		break;
	case SND_SOC_BIAS_OFF:
		/* power down the OSC and the PLL */
		snd_soc_update_bits(codec, WM8804_PWRDN, 0x9, 0x9);
		regulator_bulk_disable(ARRAY_SIZE(wm8804->supplies),
				       wm8804->supplies);
		break;
	}

	codec->dapm.bias_level = level;
	return 0;
}

static const struct snd_soc_dai_ops wm8804_dai_ops = {
	.hw_params = wm8804_hw_params,
	.set_fmt = wm8804_set_fmt,
	.set_sysclk = wm8804_set_sysclk,
	.set_clkdiv = wm8804_set_clkdiv,
	.set_pll = wm8804_set_pll
};

#define WM8804_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
			SNDRV_PCM_FMTBIT_S24_LE)

#define WM8804_RATES (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \
		      SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_64000 | \
		      SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 | \
		      SNDRV_PCM_RATE_176400 | SNDRV_PCM_RATE_192000)

static struct snd_soc_dai_driver wm8804_dai = {
	.name = "wm8804-spdif",
	.playback = {
		.stream_name = "Playback",
		.channels_min = 2,
		.channels_max = 2,
		.rates = WM8804_RATES,
		.formats = WM8804_FORMATS,
	},
	.capture = {
		.stream_name = "Capture",
		.channels_min = 2,
		.channels_max = 2,
		.rates = WM8804_RATES,
		.formats = WM8804_FORMATS,
	},
	.ops = &wm8804_dai_ops,
	.symmetric_rates = 1
};

static const struct snd_soc_codec_driver soc_codec_dev_wm8804 = {
	.set_bias_level = wm8804_set_bias_level,
	.idle_bias_off = true,

	.controls = wm8804_snd_controls,
	.num_controls = ARRAY_SIZE(wm8804_snd_controls),
};

const struct regmap_config wm8804_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = WM8804_MAX_REGISTER,
	.volatile_reg = wm8804_volatile,

	.cache_type = REGCACHE_RBTREE,
	.reg_defaults = wm8804_reg_defaults,
	.num_reg_defaults = ARRAY_SIZE(wm8804_reg_defaults),
};
EXPORT_SYMBOL_GPL(wm8804_regmap_config);

int wm8804_probe(struct device *dev, struct regmap *regmap)
{
	struct wm8804_priv *wm8804;
	unsigned int id1, id2;
	int i, ret;

	wm8804 = devm_kzalloc(dev, sizeof(*wm8804), GFP_KERNEL);
	if (!wm8804)
		return -ENOMEM;

	dev_set_drvdata(dev, wm8804);

	wm8804->regmap = regmap;

	for (i = 0; i < ARRAY_SIZE(wm8804->supplies); i++)
		wm8804->supplies[i].supply = wm8804_supply_names[i];

	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(wm8804->supplies),
				      wm8804->supplies);
	if (ret) {
		dev_err(dev, "Failed to request supplies: %d\n", ret);
		return ret;
	}

	wm8804->disable_nb[0].notifier_call = wm8804_regulator_event_0;
	wm8804->disable_nb[1].notifier_call = wm8804_regulator_event_1;

	/* This should really be moved into the regulator core */
	for (i = 0; i < ARRAY_SIZE(wm8804->supplies); i++) {
		ret = regulator_register_notifier(wm8804->supplies[i].consumer,
						  &wm8804->disable_nb[i]);
		if (ret != 0) {
			dev_err(dev,
				"Failed to register regulator notifier: %d\n",
				ret);
		}
	}

	ret = regulator_bulk_enable(ARRAY_SIZE(wm8804->supplies),
				    wm8804->supplies);
	if (ret) {
		dev_err(dev, "Failed to enable supplies: %d\n", ret);
		goto err_reg_enable;
	}

	ret = regmap_read(regmap, WM8804_RST_DEVID1, &id1);
	if (ret < 0) {
		dev_err(dev, "Failed to read device ID: %d\n", ret);
		goto err_reg_enable;
	}

	ret = regmap_read(regmap, WM8804_DEVID2, &id2);
	if (ret < 0) {
		dev_err(dev, "Failed to read device ID: %d\n", ret);
		goto err_reg_enable;
	}

	id2 = (id2 << 8) | id1;

	if (id2 != 0x8805) {
		dev_err(dev, "Invalid device ID: %#x\n", id2);
		ret = -EINVAL;
		goto err_reg_enable;
	}

	ret = regmap_read(regmap, WM8804_DEVREV, &id1);
	if (ret < 0) {
		dev_err(dev, "Failed to read device revision: %d\n",
			ret);
		goto err_reg_enable;
	}
	dev_info(dev, "revision %c\n", id1 + 'A');

	ret = wm8804_reset(wm8804);
	if (ret < 0) {
		dev_err(dev, "Failed to issue reset: %d\n", ret);
		goto err_reg_enable;
	}

	return snd_soc_register_codec(dev, &soc_codec_dev_wm8804,
				      &wm8804_dai, 1);

err_reg_enable:
	regulator_bulk_disable(ARRAY_SIZE(wm8804->supplies), wm8804->supplies);
	return ret;
}
EXPORT_SYMBOL_GPL(wm8804_probe);

void wm8804_remove(struct device *dev)
{
	struct wm8804_priv *wm8804;
	int i;

	wm8804 = dev_get_drvdata(dev);

	for (i = 0; i < ARRAY_SIZE(wm8804->supplies); ++i)
		regulator_unregister_notifier(wm8804->supplies[i].consumer,
					      &wm8804->disable_nb[i]);

	snd_soc_unregister_codec(dev);
}
EXPORT_SYMBOL_GPL(wm8804_remove);

MODULE_DESCRIPTION("ASoC WM8804 driver");
MODULE_AUTHOR("Dimitris Papastamos <dp@opensource.wolfsonmicro.com>");
MODULE_LICENSE("GPL");