summaryrefslogtreecommitdiffstats
path: root/sound/atmel/ac97c.c
blob: 380025887aef61e2aa87a7845d12a7d1ba9b85ae (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
/*
 * Driver for Atmel AC97C
 *
 * Copyright (C) 2005-2009 Atmel Corporation
 *
 * 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/clk.h>
#include <linux/delay.h>
#include <linux/bitmap.h>
#include <linux/device.h>
#include <linux/atmel_pdc.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/ac97_codec.h>
#include <sound/memalloc.h>

#include "ac97c.h"

/* Serialize access to opened variable */
static DEFINE_MUTEX(opened_mutex);

struct atmel_ac97c {
	struct clk			*pclk;
	struct platform_device		*pdev;

	struct snd_pcm_substream	*playback_substream;
	struct snd_pcm_substream	*capture_substream;
	struct snd_card			*card;
	struct snd_pcm			*pcm;
	struct snd_ac97			*ac97;
	struct snd_ac97_bus		*ac97_bus;

	u64				cur_format;
	unsigned int			cur_rate;
	int				playback_period, capture_period;
	/* Serialize access to opened variable */
	spinlock_t			lock;
	void __iomem			*regs;
	int				irq;
	int				opened;
	struct gpio_desc		*reset_pin;
};

#define get_chip(card) ((struct atmel_ac97c *)(card)->private_data)

#define ac97c_writel(chip, reg, val)			\
	__raw_writel((val), (chip)->regs + AC97C_##reg)
#define ac97c_readl(chip, reg)				\
	__raw_readl((chip)->regs + AC97C_##reg)

static const struct snd_pcm_hardware atmel_ac97c_hw = {
	.info			= (SNDRV_PCM_INFO_MMAP
				  | SNDRV_PCM_INFO_MMAP_VALID
				  | SNDRV_PCM_INFO_INTERLEAVED
				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
				  | SNDRV_PCM_INFO_JOINT_DUPLEX
				  | SNDRV_PCM_INFO_RESUME
				  | SNDRV_PCM_INFO_PAUSE),
	.formats		= (SNDRV_PCM_FMTBIT_S16_BE
				  | SNDRV_PCM_FMTBIT_S16_LE),
	.rates			= (SNDRV_PCM_RATE_CONTINUOUS),
	.rate_min		= 4000,
	.rate_max		= 48000,
	.channels_min		= 1,
	.channels_max		= 2,
	.buffer_bytes_max	= 2 * 2 * 64 * 2048,
	.period_bytes_min	= 4096,
	.period_bytes_max	= 4096,
	.periods_min		= 6,
	.periods_max		= 64,
};

static int atmel_ac97c_playback_open(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;

	mutex_lock(&opened_mutex);
	chip->opened++;
	runtime->hw = atmel_ac97c_hw;
	if (chip->cur_rate) {
		runtime->hw.rate_min = chip->cur_rate;
		runtime->hw.rate_max = chip->cur_rate;
	}
	if (chip->cur_format)
		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
	mutex_unlock(&opened_mutex);
	chip->playback_substream = substream;
	return 0;
}

static int atmel_ac97c_capture_open(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;

	mutex_lock(&opened_mutex);
	chip->opened++;
	runtime->hw = atmel_ac97c_hw;
	if (chip->cur_rate) {
		runtime->hw.rate_min = chip->cur_rate;
		runtime->hw.rate_max = chip->cur_rate;
	}
	if (chip->cur_format)
		runtime->hw.formats = pcm_format_to_bits(chip->cur_format);
	mutex_unlock(&opened_mutex);
	chip->capture_substream = substream;
	return 0;
}

static int atmel_ac97c_playback_close(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);

	mutex_lock(&opened_mutex);
	chip->opened--;
	if (!chip->opened) {
		chip->cur_rate = 0;
		chip->cur_format = 0;
	}
	mutex_unlock(&opened_mutex);

	chip->playback_substream = NULL;

	return 0;
}

static int atmel_ac97c_capture_close(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);

	mutex_lock(&opened_mutex);
	chip->opened--;
	if (!chip->opened) {
		chip->cur_rate = 0;
		chip->cur_format = 0;
	}
	mutex_unlock(&opened_mutex);

	chip->capture_substream = NULL;

	return 0;
}

static int atmel_ac97c_playback_hw_params(struct snd_pcm_substream *substream,
		struct snd_pcm_hw_params *hw_params)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	int retval;

	retval = snd_pcm_lib_malloc_pages(substream,
					params_buffer_bytes(hw_params));
	if (retval < 0)
		return retval;

	/* Set restrictions to params. */
	mutex_lock(&opened_mutex);
	chip->cur_rate = params_rate(hw_params);
	chip->cur_format = params_format(hw_params);
	mutex_unlock(&opened_mutex);

	return retval;
}

static int atmel_ac97c_capture_hw_params(struct snd_pcm_substream *substream,
		struct snd_pcm_hw_params *hw_params)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	int retval;

	retval = snd_pcm_lib_malloc_pages(substream,
					params_buffer_bytes(hw_params));
	if (retval < 0)
		return retval;

	/* Set restrictions to params. */
	mutex_lock(&opened_mutex);
	chip->cur_rate = params_rate(hw_params);
	chip->cur_format = params_format(hw_params);
	mutex_unlock(&opened_mutex);

	return retval;
}

static int atmel_ac97c_playback_prepare(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int block_size = frames_to_bytes(runtime, runtime->period_size);
	unsigned long word = ac97c_readl(chip, OCA);
	int retval;

	chip->playback_period = 0;
	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));

	/* assign channels to AC97C channel A */
	switch (runtime->channels) {
	case 1:
		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
		break;
	case 2:
		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
		break;
	default:
		/* TODO: support more than two channels */
		return -EINVAL;
	}
	ac97c_writel(chip, OCA, word);

	/* configure sample format and size */
	word = ac97c_readl(chip, CAMR);
	if (chip->opened <= 1)
		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
	else
		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;

	switch (runtime->format) {
	case SNDRV_PCM_FORMAT_S16_LE:
		break;
	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
		word &= ~(AC97C_CMR_CEM_LITTLE);
		break;
	default:
		word = ac97c_readl(chip, OCA);
		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
		ac97c_writel(chip, OCA, word);
		return -EINVAL;
	}

	/* Enable underrun interrupt on channel A */
	word |= AC97C_CSR_UNRUN;

	ac97c_writel(chip, CAMR, word);

	/* Enable channel A event interrupt */
	word = ac97c_readl(chip, IMR);
	word |= AC97C_SR_CAEVT;
	ac97c_writel(chip, IER, word);

	/* set variable rate if needed */
	if (runtime->rate != 48000) {
		word = ac97c_readl(chip, MR);
		word |= AC97C_MR_VRA;
		ac97c_writel(chip, MR, word);
	} else {
		word = ac97c_readl(chip, MR);
		word &= ~(AC97C_MR_VRA);
		ac97c_writel(chip, MR, word);
	}

	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
			runtime->rate);
	if (retval)
		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
				runtime->rate);

	/* Initialize and start the PDC */
	writel(runtime->dma_addr, chip->regs + ATMEL_PDC_TPR);
	writel(block_size / 2, chip->regs + ATMEL_PDC_TCR);
	writel(runtime->dma_addr + block_size, chip->regs + ATMEL_PDC_TNPR);
	writel(block_size / 2, chip->regs + ATMEL_PDC_TNCR);

	return retval;
}

static int atmel_ac97c_capture_prepare(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int block_size = frames_to_bytes(runtime, runtime->period_size);
	unsigned long word = ac97c_readl(chip, ICA);
	int retval;

	chip->capture_period = 0;
	word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));

	/* assign channels to AC97C channel A */
	switch (runtime->channels) {
	case 1:
		word |= AC97C_CH_ASSIGN(PCM_LEFT, A);
		break;
	case 2:
		word |= AC97C_CH_ASSIGN(PCM_LEFT, A)
			| AC97C_CH_ASSIGN(PCM_RIGHT, A);
		break;
	default:
		/* TODO: support more than two channels */
		return -EINVAL;
	}
	ac97c_writel(chip, ICA, word);

	/* configure sample format and size */
	word = ac97c_readl(chip, CAMR);
	if (chip->opened <= 1)
		word = AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;
	else
		word |= AC97C_CMR_DMAEN | AC97C_CMR_SIZE_16;

	switch (runtime->format) {
	case SNDRV_PCM_FORMAT_S16_LE:
		break;
	case SNDRV_PCM_FORMAT_S16_BE: /* fall through */
		word &= ~(AC97C_CMR_CEM_LITTLE);
		break;
	default:
		word = ac97c_readl(chip, ICA);
		word &= ~(AC97C_CH_MASK(PCM_LEFT) | AC97C_CH_MASK(PCM_RIGHT));
		ac97c_writel(chip, ICA, word);
		return -EINVAL;
	}

	/* Enable overrun interrupt on channel A */
	word |= AC97C_CSR_OVRUN;

	ac97c_writel(chip, CAMR, word);

	/* Enable channel A event interrupt */
	word = ac97c_readl(chip, IMR);
	word |= AC97C_SR_CAEVT;
	ac97c_writel(chip, IER, word);

	/* set variable rate if needed */
	if (runtime->rate != 48000) {
		word = ac97c_readl(chip, MR);
		word |= AC97C_MR_VRA;
		ac97c_writel(chip, MR, word);
	} else {
		word = ac97c_readl(chip, MR);
		word &= ~(AC97C_MR_VRA);
		ac97c_writel(chip, MR, word);
	}

	retval = snd_ac97_set_rate(chip->ac97, AC97_PCM_LR_ADC_RATE,
			runtime->rate);
	if (retval)
		dev_dbg(&chip->pdev->dev, "could not set rate %d Hz\n",
				runtime->rate);

	/* Initialize and start the PDC */
	writel(runtime->dma_addr, chip->regs + ATMEL_PDC_RPR);
	writel(block_size / 2, chip->regs + ATMEL_PDC_RCR);
	writel(runtime->dma_addr + block_size, chip->regs + ATMEL_PDC_RNPR);
	writel(block_size / 2, chip->regs + ATMEL_PDC_RNCR);

	return retval;
}

static int
atmel_ac97c_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	unsigned long camr, ptcr = 0;

	camr = ac97c_readl(chip, CAMR);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
	case SNDRV_PCM_TRIGGER_START:
		ptcr = ATMEL_PDC_TXTEN;
		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDTX;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
	case SNDRV_PCM_TRIGGER_STOP:
		ptcr |= ATMEL_PDC_TXTDIS;
		if (chip->opened <= 1)
			camr &= ~AC97C_CMR_CENA;
		break;
	default:
		return -EINVAL;
	}

	ac97c_writel(chip, CAMR, camr);
	writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
	return 0;
}

static int
atmel_ac97c_capture_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct atmel_ac97c *chip = snd_pcm_substream_chip(substream);
	unsigned long camr, ptcr = 0;

	camr = ac97c_readl(chip, CAMR);
	ptcr = readl(chip->regs + ATMEL_PDC_PTSR);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
	case SNDRV_PCM_TRIGGER_START:
		ptcr = ATMEL_PDC_RXTEN;
		camr |= AC97C_CMR_CENA | AC97C_CSR_ENDRX;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
	case SNDRV_PCM_TRIGGER_STOP:
		ptcr |= ATMEL_PDC_RXTDIS;
		if (chip->opened <= 1)
			camr &= ~AC97C_CMR_CENA;
		break;
	default:
		return -EINVAL;
	}

	ac97c_writel(chip, CAMR, camr);
	writel(ptcr, chip->regs + ATMEL_PDC_PTCR);
	return 0;
}

static snd_pcm_uframes_t
atmel_ac97c_playback_pointer(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime	*runtime = substream->runtime;
	snd_pcm_uframes_t	frames;
	unsigned long		bytes;

	bytes = readl(chip->regs + ATMEL_PDC_TPR);
	bytes -= runtime->dma_addr;

	frames = bytes_to_frames(runtime, bytes);
	if (frames >= runtime->buffer_size)
		frames -= runtime->buffer_size;
	return frames;
}

static snd_pcm_uframes_t
atmel_ac97c_capture_pointer(struct snd_pcm_substream *substream)
{
	struct atmel_ac97c	*chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime	*runtime = substream->runtime;
	snd_pcm_uframes_t	frames;
	unsigned long		bytes;

	bytes = readl(chip->regs + ATMEL_PDC_RPR);
	bytes -= runtime->dma_addr;

	frames = bytes_to_frames(runtime, bytes);
	if (frames >= runtime->buffer_size)
		frames -= runtime->buffer_size;
	return frames;
}

static const struct snd_pcm_ops atmel_ac97_playback_ops = {
	.open		= atmel_ac97c_playback_open,
	.close		= atmel_ac97c_playback_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= atmel_ac97c_playback_hw_params,
	.hw_free	= snd_pcm_lib_free_pages,
	.prepare	= atmel_ac97c_playback_prepare,
	.trigger	= atmel_ac97c_playback_trigger,
	.pointer	= atmel_ac97c_playback_pointer,
};

static const struct snd_pcm_ops atmel_ac97_capture_ops = {
	.open		= atmel_ac97c_capture_open,
	.close		= atmel_ac97c_capture_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= atmel_ac97c_capture_hw_params,
	.hw_free	= snd_pcm_lib_free_pages,
	.prepare	= atmel_ac97c_capture_prepare,
	.trigger	= atmel_ac97c_capture_trigger,
	.pointer	= atmel_ac97c_capture_pointer,
};

static irqreturn_t atmel_ac97c_interrupt(int irq, void *dev)
{
	struct atmel_ac97c	*chip  = (struct atmel_ac97c *)dev;
	irqreturn_t		retval = IRQ_NONE;
	u32			sr     = ac97c_readl(chip, SR);
	u32			casr   = ac97c_readl(chip, CASR);
	u32			cosr   = ac97c_readl(chip, COSR);
	u32			camr   = ac97c_readl(chip, CAMR);

	if (sr & AC97C_SR_CAEVT) {
		struct snd_pcm_runtime *runtime;
		int offset, next_period, block_size;
		dev_dbg(&chip->pdev->dev, "channel A event%s%s%s%s%s%s\n",
				casr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
				casr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
				casr & AC97C_CSR_UNRUN   ? " UNRUN"   : "",
				casr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
				casr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
				!casr                    ? " NONE"    : "");
		if ((casr & camr) & AC97C_CSR_ENDTX) {
			runtime = chip->playback_substream->runtime;
			block_size = frames_to_bytes(runtime, runtime->period_size);
			chip->playback_period++;

			if (chip->playback_period == runtime->periods)
				chip->playback_period = 0;
			next_period = chip->playback_period + 1;
			if (next_period == runtime->periods)
				next_period = 0;

			offset = block_size * next_period;

			writel(runtime->dma_addr + offset, chip->regs + ATMEL_PDC_TNPR);
			writel(block_size / 2, chip->regs + ATMEL_PDC_TNCR);

			snd_pcm_period_elapsed(chip->playback_substream);
		}
		if ((casr & camr) & AC97C_CSR_ENDRX) {
			runtime = chip->capture_substream->runtime;
			block_size = frames_to_bytes(runtime, runtime->period_size);
			chip->capture_period++;

			if (chip->capture_period == runtime->periods)
				chip->capture_period = 0;
			next_period = chip->capture_period + 1;
			if (next_period == runtime->periods)
				next_period = 0;

			offset = block_size * next_period;

			writel(runtime->dma_addr + offset, chip->regs + ATMEL_PDC_RNPR);
			writel(block_size / 2, chip->regs + ATMEL_PDC_RNCR);
			snd_pcm_period_elapsed(chip->capture_substream);
		}
		retval = IRQ_HANDLED;
	}

	if (sr & AC97C_SR_COEVT) {
		dev_info(&chip->pdev->dev, "codec channel event%s%s%s%s%s\n",
				cosr & AC97C_CSR_OVRUN   ? " OVRUN"   : "",
				cosr & AC97C_CSR_RXRDY   ? " RXRDY"   : "",
				cosr & AC97C_CSR_TXEMPTY ? " TXEMPTY" : "",
				cosr & AC97C_CSR_TXRDY   ? " TXRDY"   : "",
				!cosr                    ? " NONE"    : "");
		retval = IRQ_HANDLED;
	}

	if (retval == IRQ_NONE) {
		dev_err(&chip->pdev->dev, "spurious interrupt sr 0x%08x "
				"casr 0x%08x cosr 0x%08x\n", sr, casr, cosr);
	}

	return retval;
}

static const struct ac97_pcm at91_ac97_pcm_defs[] = {
	/* Playback */
	{
		.exclusive = 1,
		.r = { {
			.slots = ((1 << AC97_SLOT_PCM_LEFT)
				  | (1 << AC97_SLOT_PCM_RIGHT)),
		} },
	},
	/* PCM in */
	{
		.stream = 1,
		.exclusive = 1,
		.r = { {
			.slots = ((1 << AC97_SLOT_PCM_LEFT)
					| (1 << AC97_SLOT_PCM_RIGHT)),
		} }
	},
	/* Mic in */
	{
		.stream = 1,
		.exclusive = 1,
		.r = { {
			.slots = (1<<AC97_SLOT_MIC),
		} }
	},
};

static int atmel_ac97c_pcm_new(struct atmel_ac97c *chip)
{
	struct snd_pcm		*pcm;
	struct snd_pcm_hardware	hw = atmel_ac97c_hw;
	int			retval;

	retval = snd_ac97_pcm_assign(chip->ac97_bus,
				     ARRAY_SIZE(at91_ac97_pcm_defs),
				     at91_ac97_pcm_defs);
	if (retval)
		return retval;

	retval = snd_pcm_new(chip->card, chip->card->shortname, 0, 1, 1, &pcm);
	if (retval)
		return retval;

	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &atmel_ac97_capture_ops);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_ac97_playback_ops);

	retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
			&chip->pdev->dev, hw.periods_min * hw.period_bytes_min,
			hw.buffer_bytes_max);
	if (retval)
		return retval;

	pcm->private_data = chip;
	pcm->info_flags = 0;
	strcpy(pcm->name, chip->card->shortname);
	chip->pcm = pcm;

	return 0;
}

static int atmel_ac97c_mixer_new(struct atmel_ac97c *chip)
{
	struct snd_ac97_template template;
	memset(&template, 0, sizeof(template));
	template.private_data = chip;
	return snd_ac97_mixer(chip->ac97_bus, &template, &chip->ac97);
}

static void atmel_ac97c_write(struct snd_ac97 *ac97, unsigned short reg,
		unsigned short val)
{
	struct atmel_ac97c *chip = get_chip(ac97);
	unsigned long word;
	int timeout = 40;

	word = (reg & 0x7f) << 16 | val;

	do {
		if (ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) {
			ac97c_writel(chip, COTHR, word);
			return;
		}
		udelay(1);
	} while (--timeout);

	dev_dbg(&chip->pdev->dev, "codec write timeout\n");
}

static unsigned short atmel_ac97c_read(struct snd_ac97 *ac97,
		unsigned short reg)
{
	struct atmel_ac97c *chip = get_chip(ac97);
	unsigned long word;
	int timeout = 40;
	int write = 10;

	word = (0x80 | (reg & 0x7f)) << 16;

	if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0)
		ac97c_readl(chip, CORHR);

retry_write:
	timeout = 40;

	do {
		if ((ac97c_readl(chip, COSR) & AC97C_CSR_TXRDY) != 0) {
			ac97c_writel(chip, COTHR, word);
			goto read_reg;
		}
		udelay(10);
	} while (--timeout);

	if (!--write)
		goto timed_out;
	goto retry_write;

read_reg:
	do {
		if ((ac97c_readl(chip, COSR) & AC97C_CSR_RXRDY) != 0) {
			unsigned short val = ac97c_readl(chip, CORHR);
			return val;
		}
		udelay(10);
	} while (--timeout);

	if (!--write)
		goto timed_out;
	goto retry_write;

timed_out:
	dev_dbg(&chip->pdev->dev, "codec read timeout\n");
	return 0xffff;
}

static void atmel_ac97c_reset(struct atmel_ac97c *chip)
{
	ac97c_writel(chip, MR,   0);
	ac97c_writel(chip, MR,   AC97C_MR_ENA);
	ac97c_writel(chip, CAMR, 0);
	ac97c_writel(chip, COMR, 0);

	if (!IS_ERR(chip->reset_pin)) {
		gpiod_set_value(chip->reset_pin, 0);
		/* AC97 v2.2 specifications says minimum 1 us. */
		udelay(2);
		gpiod_set_value(chip->reset_pin, 1);
	} else {
		ac97c_writel(chip, MR, AC97C_MR_WRST | AC97C_MR_ENA);
		udelay(2);
		ac97c_writel(chip, MR, AC97C_MR_ENA);
	}
}

static const struct of_device_id atmel_ac97c_dt_ids[] = {
	{ .compatible = "atmel,at91sam9263-ac97c", },
	{ }
};
MODULE_DEVICE_TABLE(of, atmel_ac97c_dt_ids);

static int atmel_ac97c_probe(struct platform_device *pdev)
{
	struct device			*dev = &pdev->dev;
	struct snd_card			*card;
	struct atmel_ac97c		*chip;
	struct resource			*regs;
	struct clk			*pclk;
	static struct snd_ac97_bus_ops	ops = {
		.write	= atmel_ac97c_write,
		.read	= atmel_ac97c_read,
	};
	int				retval;
	int				irq;

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs) {
		dev_dbg(&pdev->dev, "no memory resource\n");
		return -ENXIO;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_dbg(&pdev->dev, "could not get irq: %d\n", irq);
		return irq;
	}

	pclk = clk_get(&pdev->dev, "ac97_clk");
	if (IS_ERR(pclk)) {
		dev_dbg(&pdev->dev, "no peripheral clock\n");
		return PTR_ERR(pclk);
	}
	retval = clk_prepare_enable(pclk);
	if (retval)
		goto err_prepare_enable;

	retval = snd_card_new(&pdev->dev, SNDRV_DEFAULT_IDX1,
			      SNDRV_DEFAULT_STR1, THIS_MODULE,
			      sizeof(struct atmel_ac97c), &card);
	if (retval) {
		dev_dbg(&pdev->dev, "could not create sound card device\n");
		goto err_snd_card_new;
	}

	chip = get_chip(card);

	retval = request_irq(irq, atmel_ac97c_interrupt, 0, "AC97C", chip);
	if (retval) {
		dev_dbg(&pdev->dev, "unable to request irq %d\n", irq);
		goto err_request_irq;
	}
	chip->irq = irq;

	spin_lock_init(&chip->lock);

	strcpy(card->driver, "Atmel AC97C");
	strcpy(card->shortname, "Atmel AC97C");
	sprintf(card->longname, "Atmel AC97 controller");

	chip->card = card;
	chip->pclk = pclk;
	chip->pdev = pdev;
	chip->regs = ioremap(regs->start, resource_size(regs));

	if (!chip->regs) {
		dev_dbg(&pdev->dev, "could not remap register memory\n");
		retval = -ENOMEM;
		goto err_ioremap;
	}

	chip->reset_pin = devm_gpiod_get_index(dev, "ac97", 2, GPIOD_OUT_HIGH);
	if (IS_ERR(chip->reset_pin))
		dev_dbg(dev, "reset pin not available\n");

	atmel_ac97c_reset(chip);

	/* Enable overrun interrupt from codec channel */
	ac97c_writel(chip, COMR, AC97C_CSR_OVRUN);
	ac97c_writel(chip, IER, ac97c_readl(chip, IMR) | AC97C_SR_COEVT);

	retval = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus);
	if (retval) {
		dev_dbg(&pdev->dev, "could not register on ac97 bus\n");
		goto err_ac97_bus;
	}

	retval = atmel_ac97c_mixer_new(chip);
	if (retval) {
		dev_dbg(&pdev->dev, "could not register ac97 mixer\n");
		goto err_ac97_bus;
	}

	retval = atmel_ac97c_pcm_new(chip);
	if (retval) {
		dev_dbg(&pdev->dev, "could not register ac97 pcm device\n");
		goto err_ac97_bus;
	}

	retval = snd_card_register(card);
	if (retval) {
		dev_dbg(&pdev->dev, "could not register sound card\n");
		goto err_ac97_bus;
	}

	platform_set_drvdata(pdev, card);

	dev_info(&pdev->dev, "Atmel AC97 controller at 0x%p, irq = %d\n",
			chip->regs, irq);

	return 0;

err_ac97_bus:
	iounmap(chip->regs);
err_ioremap:
	free_irq(irq, chip);
err_request_irq:
	snd_card_free(card);
err_snd_card_new:
	clk_disable_unprepare(pclk);
err_prepare_enable:
	clk_put(pclk);
	return retval;
}

#ifdef CONFIG_PM_SLEEP
static int atmel_ac97c_suspend(struct device *pdev)
{
	struct snd_card *card = dev_get_drvdata(pdev);
	struct atmel_ac97c *chip = card->private_data;

	clk_disable_unprepare(chip->pclk);
	return 0;
}

static int atmel_ac97c_resume(struct device *pdev)
{
	struct snd_card *card = dev_get_drvdata(pdev);
	struct atmel_ac97c *chip = card->private_data;
	int ret = clk_prepare_enable(chip->pclk);

	return ret;
}

static SIMPLE_DEV_PM_OPS(atmel_ac97c_pm, atmel_ac97c_suspend, atmel_ac97c_resume);
#define ATMEL_AC97C_PM_OPS	&atmel_ac97c_pm
#else
#define ATMEL_AC97C_PM_OPS	NULL
#endif

static int atmel_ac97c_remove(struct platform_device *pdev)
{
	struct snd_card *card = platform_get_drvdata(pdev);
	struct atmel_ac97c *chip = get_chip(card);

	ac97c_writel(chip, CAMR, 0);
	ac97c_writel(chip, COMR, 0);
	ac97c_writel(chip, MR,   0);

	clk_disable_unprepare(chip->pclk);
	clk_put(chip->pclk);
	iounmap(chip->regs);
	free_irq(chip->irq, chip);

	snd_card_free(card);

	return 0;
}

static struct platform_driver atmel_ac97c_driver = {
	.probe		= atmel_ac97c_probe,
	.remove		= atmel_ac97c_remove,
	.driver		= {
		.name	= "atmel_ac97c",
		.pm	= ATMEL_AC97C_PM_OPS,
		.of_match_table = atmel_ac97c_dt_ids,
	},
};
module_platform_driver(atmel_ac97c_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Driver for Atmel AC97 controller");
MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");