summaryrefslogtreecommitdiff
path: root/sound/soc/fsl/mpc5200_psc_i2s.c
blob: 86923299bc1049d9a74d274d449d6f0e5f32494e (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
/*
 * Freescale MPC5200 PSC in I2S mode
 * ALSA SoC Digital Audio Interface (DAI) driver
 *
 * Copyright (C) 2008 Secret Lab Technologies Ltd.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/dma-mapping.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/soc-of-simple.h>

#include <sysdev/bestcomm/bestcomm.h>
#include <sysdev/bestcomm/gen_bd.h>
#include <asm/mpc52xx_psc.h>

MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver");
MODULE_LICENSE("GPL");

/**
 * PSC_I2S_RATES: sample rates supported by the I2S
 *
 * This driver currently only supports the PSC running in I2S slave mode,
 * which means the codec determines the sample rate.  Therefore, we tell
 * ALSA that we support all rates and let the codec driver decide what rates
 * are really supported.
 */
#define PSC_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \
			SNDRV_PCM_RATE_CONTINUOUS)

/**
 * PSC_I2S_FORMATS: audio formats supported by the PSC I2S mode
 */
#define PSC_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
			 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_BE | \
			 SNDRV_PCM_FMTBIT_S32_BE)

/**
 * psc_i2s_stream - Data specific to a single stream (playback or capture)
 * @active:		flag indicating if the stream is active
 * @psc_i2s:		pointer back to parent psc_i2s data structure
 * @bcom_task:		bestcomm task structure
 * @irq:		irq number for bestcomm task
 * @period_start:	physical address of start of DMA region
 * @period_end:		physical address of end of DMA region
 * @period_next_pt:	physical address of next DMA buffer to enqueue
 * @period_bytes:	size of DMA period in bytes
 */
struct psc_i2s_stream {
	int active;
	struct psc_i2s *psc_i2s;
	struct bcom_task *bcom_task;
	int irq;
	struct snd_pcm_substream *stream;
	dma_addr_t period_start;
	dma_addr_t period_end;
	dma_addr_t period_next_pt;
	dma_addr_t period_current_pt;
	int period_bytes;
};

/**
 * psc_i2s - Private driver data
 * @name: short name for this device ("PSC0", "PSC1", etc)
 * @psc_regs: pointer to the PSC's registers
 * @fifo_regs: pointer to the PSC's FIFO registers
 * @irq: IRQ of this PSC
 * @dev: struct device pointer
 * @dai: the CPU DAI for this device
 * @sicr: Base value used in serial interface control register; mode is ORed
 *        with this value.
 * @playback: Playback stream context data
 * @capture: Capture stream context data
 */
struct psc_i2s {
	char name[32];
	struct mpc52xx_psc __iomem *psc_regs;
	struct mpc52xx_psc_fifo __iomem *fifo_regs;
	unsigned int irq;
	struct device *dev;
	struct snd_soc_dai dai;
	spinlock_t lock;
	u32 sicr;

	/* per-stream data */
	struct psc_i2s_stream playback;
	struct psc_i2s_stream capture;

	/* Statistics */
	struct {
		int overrun_count;
		int underrun_count;
	} stats;
};

/*
 * Interrupt handlers
 */
static irqreturn_t psc_i2s_status_irq(int irq, void *_psc_i2s)
{
	struct psc_i2s *psc_i2s = _psc_i2s;
	struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
	u16 isr;

	isr = in_be16(&regs->mpc52xx_psc_isr);

	/* Playback underrun error */
	if (psc_i2s->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
		psc_i2s->stats.underrun_count++;

	/* Capture overrun error */
	if (psc_i2s->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
		psc_i2s->stats.overrun_count++;

	out_8(&regs->command, 4 << 4);	/* reset the error status */

	return IRQ_HANDLED;
}

/**
 * psc_i2s_bcom_enqueue_next_buffer - Enqueue another audio buffer
 * @s: pointer to stream private data structure
 *
 * Enqueues another audio period buffer into the bestcomm queue.
 *
 * Note: The routine must only be called when there is space available in
 * the queue.  Otherwise the enqueue will fail and the audio ring buffer
 * will get out of sync
 */
static void psc_i2s_bcom_enqueue_next_buffer(struct psc_i2s_stream *s)
{
	struct bcom_bd *bd;

	/* Prepare and enqueue the next buffer descriptor */
	bd = bcom_prepare_next_buffer(s->bcom_task);
	bd->status = s->period_bytes;
	bd->data[0] = s->period_next_pt;
	bcom_submit_next_buffer(s->bcom_task, NULL);

	/* Update for next period */
	s->period_next_pt += s->period_bytes;
	if (s->period_next_pt >= s->period_end)
		s->period_next_pt = s->period_start;
}

/* Bestcomm DMA irq handler */
static irqreturn_t psc_i2s_bcom_irq(int irq, void *_psc_i2s_stream)
{
	struct psc_i2s_stream *s = _psc_i2s_stream;

	/* For each finished period, dequeue the completed period buffer
	 * and enqueue a new one in it's place. */
	while (bcom_buffer_done(s->bcom_task)) {
		bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
		s->period_current_pt += s->period_bytes;
		if (s->period_current_pt >= s->period_end)
			s->period_current_pt = s->period_start;
		psc_i2s_bcom_enqueue_next_buffer(s);
		bcom_enable(s->bcom_task);
	}

	/* If the stream is active, then also inform the PCM middle layer
	 * of the period finished event. */
	if (s->active)
		snd_pcm_period_elapsed(s->stream);

	return IRQ_HANDLED;
}

/**
 * psc_i2s_startup: create a new substream
 *
 * This is the first function called when a stream is opened.
 *
 * If this is the first stream open, then grab the IRQ and program most of
 * the PSC registers.
 */
static int psc_i2s_startup(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	int rc;

	dev_dbg(psc_i2s->dev, "psc_i2s_startup(substream=%p)\n", substream);

	if (!psc_i2s->playback.active &&
	    !psc_i2s->capture.active) {
		/* Setup the IRQs */
		rc = request_irq(psc_i2s->irq, &psc_i2s_status_irq, IRQF_SHARED,
				 "psc-i2s-status", psc_i2s);
		rc |= request_irq(psc_i2s->capture.irq,
				  &psc_i2s_bcom_irq, IRQF_SHARED,
				  "psc-i2s-capture", &psc_i2s->capture);
		rc |= request_irq(psc_i2s->playback.irq,
				  &psc_i2s_bcom_irq, IRQF_SHARED,
				  "psc-i2s-playback", &psc_i2s->playback);
		if (rc) {
			free_irq(psc_i2s->irq, psc_i2s);
			free_irq(psc_i2s->capture.irq,
				 &psc_i2s->capture);
			free_irq(psc_i2s->playback.irq,
				 &psc_i2s->playback);
			return -ENODEV;
		}
	}

	return 0;
}

static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
				 struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	u32 mode;

	dev_dbg(psc_i2s->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
		" periods=%i buffer_size=%i  buffer_bytes=%i\n",
		__func__, substream, params_period_size(params),
		params_period_bytes(params), params_periods(params),
		params_buffer_size(params), params_buffer_bytes(params));

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
		break;
	case SNDRV_PCM_FORMAT_S16_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
		break;
	case SNDRV_PCM_FORMAT_S24_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
		break;
	case SNDRV_PCM_FORMAT_S32_BE:
		mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
		break;
	default:
		dev_dbg(psc_i2s->dev, "invalid format\n");
		return -EINVAL;
	}
	out_be32(&psc_i2s->psc_regs->sicr, psc_i2s->sicr | mode);

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	return 0;
}

static int psc_i2s_hw_free(struct snd_pcm_substream *substream)
{
	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}

/**
 * psc_i2s_trigger: start and stop the DMA transfer.
 *
 * This function is called by ALSA to start, stop, pause, and resume the DMA
 * transfer of data.
 */
static int psc_i2s_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct psc_i2s_stream *s;
	struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
	u16 imr;
	u8 psc_cmd;
	long flags;

	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
		s = &psc_i2s->capture;
	else
		s = &psc_i2s->playback;

	dev_dbg(psc_i2s->dev, "psc_i2s_trigger(substream=%p, cmd=%i)"
		" stream_id=%i\n",
		substream, cmd, substream->pstr->stream);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		s->period_bytes = frames_to_bytes(runtime,
						  runtime->period_size);
		s->period_start = virt_to_phys(runtime->dma_area);
		s->period_end = s->period_start +
				(s->period_bytes * runtime->periods);
		s->period_next_pt = s->period_start;
		s->period_current_pt = s->period_start;
		s->active = 1;

		/* First; reset everything */
		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
			out_8(&regs->command, MPC52xx_PSC_RST_RX);
			out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
		} else {
			out_8(&regs->command, MPC52xx_PSC_RST_TX);
			out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
		}

		/* Next, fill up the bestcomm bd queue and enable DMA.
		 * This will begin filling the PSC's fifo. */
		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
			bcom_gen_bd_rx_reset(s->bcom_task);
		else
			bcom_gen_bd_tx_reset(s->bcom_task);
		while (!bcom_queue_full(s->bcom_task))
			psc_i2s_bcom_enqueue_next_buffer(s);
		bcom_enable(s->bcom_task);

		/* Due to errata in the i2s mode; need to line up enabling
		 * the transmitter with a transition on the frame sync
		 * line */

		spin_lock_irqsave(&psc_i2s->lock, flags);
		/* first make sure it is low */
		while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) != 0)
			;
		/* then wait for the transition to high */
		while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) == 0)
			;
		/* Finally, enable the PSC.
		 * Receiver must always be enabled; even when we only want
		 * transmit.  (see 15.3.2.3 of MPC5200B User's Guide) */
		psc_cmd = MPC52xx_PSC_RX_ENABLE;
		if (substream->pstr->stream == SNDRV_PCM_STREAM_PLAYBACK)
			psc_cmd |= MPC52xx_PSC_TX_ENABLE;
		out_8(&regs->command, psc_cmd);
		spin_unlock_irqrestore(&psc_i2s->lock, flags);

		break;

	case SNDRV_PCM_TRIGGER_STOP:
		/* Turn off the PSC */
		s->active = 0;
		if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
			if (!psc_i2s->playback.active) {
				out_8(&regs->command, 2 << 4);	/* reset rx */
				out_8(&regs->command, 3 << 4);	/* reset tx */
				out_8(&regs->command, 4 << 4);	/* reset err */
			}
		} else {
			out_8(&regs->command, 3 << 4);	/* reset tx */
			out_8(&regs->command, 4 << 4);	/* reset err */
			if (!psc_i2s->capture.active)
				out_8(&regs->command, 2 << 4);	/* reset rx */
		}

		bcom_disable(s->bcom_task);
		while (!bcom_queue_empty(s->bcom_task))
			bcom_retrieve_buffer(s->bcom_task, NULL, NULL);

		break;

	default:
		dev_dbg(psc_i2s->dev, "invalid command\n");
		return -EINVAL;
	}

	/* Update interrupt enable settings */
	imr = 0;
	if (psc_i2s->playback.active)
		imr |= MPC52xx_PSC_IMR_TXEMP;
	if (psc_i2s->capture.active)
		imr |= MPC52xx_PSC_IMR_ORERR;
	out_be16(&regs->isr_imr.imr, imr);

	return 0;
}

/**
 * psc_i2s_shutdown: shutdown the data transfer on a stream
 *
 * Shutdown the PSC if there are no other substreams open.
 */
static void psc_i2s_shutdown(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;

	dev_dbg(psc_i2s->dev, "psc_i2s_shutdown(substream=%p)\n", substream);

	/*
	 * If this is the last active substream, disable the PSC and release
	 * the IRQ.
	 */
	if (!psc_i2s->playback.active &&
	    !psc_i2s->capture.active) {

		/* Disable all interrupts and reset the PSC */
		out_be16(&psc_i2s->psc_regs->isr_imr.imr, 0);
		out_8(&psc_i2s->psc_regs->command, 3 << 4); /* reset tx */
		out_8(&psc_i2s->psc_regs->command, 2 << 4); /* reset rx */
		out_8(&psc_i2s->psc_regs->command, 1 << 4); /* reset mode */
		out_8(&psc_i2s->psc_regs->command, 4 << 4); /* reset error */

		/* Release irqs */
		free_irq(psc_i2s->irq, psc_i2s);
		free_irq(psc_i2s->capture.irq, &psc_i2s->capture);
		free_irq(psc_i2s->playback.irq, &psc_i2s->playback);
	}
}

/**
 * psc_i2s_set_sysclk: set the clock frequency and direction
 *
 * This function is called by the machine driver to tell us what the clock
 * frequency and direction are.
 *
 * Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
 * and we don't care about the frequency.  Return an error if the direction
 * is not SND_SOC_CLOCK_IN.
 *
 * @clk_id: reserved, should be zero
 * @freq: the frequency of the given clock ID, currently ignored
 * @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
 */
static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
			      int clk_id, unsigned int freq, int dir)
{
	struct psc_i2s *psc_i2s = cpu_dai->private_data;
	dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",
				cpu_dai, dir);
	return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
}

/**
 * psc_i2s_set_fmt: set the serial format.
 *
 * This function is called by the machine driver to tell us what serial
 * format to use.
 *
 * This driver only supports I2S mode.  Return an error if the format is
 * not SND_SOC_DAIFMT_I2S.
 *
 * @format: one of SND_SOC_DAIFMT_xxx
 */
static int psc_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int format)
{
	struct psc_i2s *psc_i2s = cpu_dai->private_data;
	dev_dbg(psc_i2s->dev, "psc_i2s_set_fmt(cpu_dai=%p, format=%i)\n",
				cpu_dai, format);
	return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;
}

/* ---------------------------------------------------------------------
 * ALSA SoC Bindings
 *
 * - Digital Audio Interface (DAI) template
 * - create/destroy dai hooks
 */

/**
 * psc_i2s_dai_template: template CPU Digital Audio Interface
 */
static struct snd_soc_dai psc_i2s_dai_template = {
	.type = SND_SOC_DAI_I2S,
	.playback = {
		.channels_min = 2,
		.channels_max = 2,
		.rates = PSC_I2S_RATES,
		.formats = PSC_I2S_FORMATS,
	},
	.capture = {
		.channels_min = 2,
		.channels_max = 2,
		.rates = PSC_I2S_RATES,
		.formats = PSC_I2S_FORMATS,
	},
	.ops = {
		.startup = psc_i2s_startup,
		.hw_params = psc_i2s_hw_params,
		.hw_free = psc_i2s_hw_free,
		.shutdown = psc_i2s_shutdown,
		.trigger = psc_i2s_trigger,
	},
	.dai_ops = {
		.set_sysclk = psc_i2s_set_sysclk,
		.set_fmt = psc_i2s_set_fmt,
	},
};

/* ---------------------------------------------------------------------
 * The PSC I2S 'ASoC platform' driver
 *
 * Can be referenced by an 'ASoC machine' driver
 * This driver only deals with the audio bus; it doesn't have any
 * interaction with the attached codec
 */

static const struct snd_pcm_hardware psc_i2s_pcm_hardware = {
	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
		SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER,
	.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
		   SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
	.rate_min = 8000,
	.rate_max = 48000,
	.channels_min = 2,
	.channels_max = 2,
	.period_bytes_max	= 1024 * 1024,
	.period_bytes_min	= 32,
	.periods_min		= 2,
	.periods_max		= 256,
	.buffer_bytes_max	= 2 * 1024 * 1024,
	.fifo_size		= 0,
};

static int psc_i2s_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	struct psc_i2s_stream *s;

	dev_dbg(psc_i2s->dev, "psc_i2s_pcm_open(substream=%p)\n", substream);

	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
		s = &psc_i2s->capture;
	else
		s = &psc_i2s->playback;

	snd_soc_set_runtime_hwparams(substream, &psc_i2s_pcm_hardware);

	s->stream = substream;
	return 0;
}

static int psc_i2s_pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	struct psc_i2s_stream *s;

	dev_dbg(psc_i2s->dev, "psc_i2s_pcm_close(substream=%p)\n", substream);

	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
		s = &psc_i2s->capture;
	else
		s = &psc_i2s->playback;

	s->stream = NULL;
	return 0;
}

static snd_pcm_uframes_t
psc_i2s_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
	struct psc_i2s_stream *s;
	dma_addr_t count;

	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
		s = &psc_i2s->capture;
	else
		s = &psc_i2s->playback;

	count = s->period_current_pt - s->period_start;

	return bytes_to_frames(substream->runtime, count);
}

static struct snd_pcm_ops psc_i2s_pcm_ops = {
	.open		= psc_i2s_pcm_open,
	.close		= psc_i2s_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.pointer	= psc_i2s_pcm_pointer,
};

static u64 psc_i2s_pcm_dmamask = 0xffffffff;
static int psc_i2s_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
			   struct snd_pcm *pcm)
{
	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
	size_t size = psc_i2s_pcm_hardware.buffer_bytes_max;
	int rc = 0;

	dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_new(card=%p, dai=%p, pcm=%p)\n",
		card, dai, pcm);

	if (!card->dev->dma_mask)
		card->dev->dma_mask = &psc_i2s_pcm_dmamask;
	if (!card->dev->coherent_dma_mask)
		card->dev->coherent_dma_mask = 0xffffffff;

	if (pcm->streams[0].substream) {
		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,
					&pcm->streams[0].substream->dma_buffer);
		if (rc)
			goto playback_alloc_err;
	}

	if (pcm->streams[1].substream) {
		rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,
					&pcm->streams[1].substream->dma_buffer);
		if (rc)
			goto capture_alloc_err;
	}

	return 0;

 capture_alloc_err:
	if (pcm->streams[0].substream)
		snd_dma_free_pages(&pcm->streams[0].substream->dma_buffer);
 playback_alloc_err:
	dev_err(card->dev, "Cannot allocate buffer(s)\n");
	return -ENOMEM;
}

static void psc_i2s_pcm_free(struct snd_pcm *pcm)
{
	struct snd_soc_pcm_runtime *rtd = pcm->private_data;
	struct snd_pcm_substream *substream;
	int stream;

	dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_free(pcm=%p)\n", pcm);

	for (stream = 0; stream < 2; stream++) {
		substream = pcm->streams[stream].substream;
		if (substream) {
			snd_dma_free_pages(&substream->dma_buffer);
			substream->dma_buffer.area = NULL;
			substream->dma_buffer.addr = 0;
		}
	}
}

struct snd_soc_platform psc_i2s_pcm_soc_platform = {
	.name		= "mpc5200-psc-audio",
	.pcm_ops	= &psc_i2s_pcm_ops,
	.pcm_new	= &psc_i2s_pcm_new,
	.pcm_free	= &psc_i2s_pcm_free,
};

/* ---------------------------------------------------------------------
 * Sysfs attributes for debugging
 */

static ssize_t psc_i2s_status_show(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);

	return sprintf(buf, "status=%.4x sicr=%.8x rfnum=%i rfstat=0x%.4x "
			"tfnum=%i tfstat=0x%.4x\n",
			in_be16(&psc_i2s->psc_regs->sr_csr.status),
			in_be32(&psc_i2s->psc_regs->sicr),
			in_be16(&psc_i2s->fifo_regs->rfnum) & 0x1ff,
			in_be16(&psc_i2s->fifo_regs->rfstat),
			in_be16(&psc_i2s->fifo_regs->tfnum) & 0x1ff,
			in_be16(&psc_i2s->fifo_regs->tfstat));
}

static int *psc_i2s_get_stat_attr(struct psc_i2s *psc_i2s, const char *name)
{
	if (strcmp(name, "playback_underrun") == 0)
		return &psc_i2s->stats.underrun_count;
	if (strcmp(name, "capture_overrun") == 0)
		return &psc_i2s->stats.overrun_count;

	return NULL;
}

static ssize_t psc_i2s_stat_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
	int *attrib;

	attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
	if (!attrib)
		return 0;

	return sprintf(buf, "%i\n", *attrib);
}

static ssize_t psc_i2s_stat_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t count)
{
	struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
	int *attrib;

	attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
	if (!attrib)
		return 0;

	*attrib = simple_strtoul(buf, NULL, 0);
	return count;
}

DEVICE_ATTR(status, 0644, psc_i2s_status_show, NULL);
DEVICE_ATTR(playback_underrun, 0644, psc_i2s_stat_show, psc_i2s_stat_store);
DEVICE_ATTR(capture_overrun, 0644, psc_i2s_stat_show, psc_i2s_stat_store);

/* ---------------------------------------------------------------------
 * OF platform bus binding code:
 * - Probe/remove operations
 * - OF device match table
 */
static int __devinit psc_i2s_of_probe(struct of_device *op,
				      const struct of_device_id *match)
{
	phys_addr_t fifo;
	struct psc_i2s *psc_i2s;
	struct resource res;
	int size, psc_id, irq, rc;
	const __be32 *prop;
	void __iomem *regs;

	dev_dbg(&op->dev, "probing psc i2s device\n");

	/* Get the PSC ID */
	prop = of_get_property(op->node, "cell-index", &size);
	if (!prop || size < sizeof *prop)
		return -ENODEV;
	psc_id = be32_to_cpu(*prop);

	/* Fetch the registers and IRQ of the PSC */
	irq = irq_of_parse_and_map(op->node, 0);
	if (of_address_to_resource(op->node, 0, &res)) {
		dev_err(&op->dev, "Missing reg property\n");
		return -ENODEV;
	}
	regs = ioremap(res.start, 1 + res.end - res.start);
	if (!regs) {
		dev_err(&op->dev, "Could not map registers\n");
		return -ENODEV;
	}

	/* Allocate and initialize the driver private data */
	psc_i2s = kzalloc(sizeof *psc_i2s, GFP_KERNEL);
	if (!psc_i2s) {
		iounmap(regs);
		return -ENOMEM;
	}
	spin_lock_init(&psc_i2s->lock);
	psc_i2s->irq = irq;
	psc_i2s->psc_regs = regs;
	psc_i2s->fifo_regs = regs + sizeof *psc_i2s->psc_regs;
	psc_i2s->dev = &op->dev;
	psc_i2s->playback.psc_i2s = psc_i2s;
	psc_i2s->capture.psc_i2s = psc_i2s;
	snprintf(psc_i2s->name, sizeof psc_i2s->name, "PSC%u", psc_id+1);

	/* Fill out the CPU DAI structure */
	memcpy(&psc_i2s->dai, &psc_i2s_dai_template, sizeof psc_i2s->dai);
	psc_i2s->dai.private_data = psc_i2s;
	psc_i2s->dai.name = psc_i2s->name;
	psc_i2s->dai.id = psc_id;

	/* Find the address of the fifo data registers and setup the
	 * DMA tasks */
	fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
	psc_i2s->capture.bcom_task =
		bcom_psc_gen_bd_rx_init(psc_id, 10, fifo, 512);
	psc_i2s->playback.bcom_task =
		bcom_psc_gen_bd_tx_init(psc_id, 10, fifo);
	if (!psc_i2s->capture.bcom_task ||
	    !psc_i2s->playback.bcom_task) {
		dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
		iounmap(regs);
		kfree(psc_i2s);
		return -ENODEV;
	}

	/* Disable all interrupts and reset the PSC */
	out_be16(&psc_i2s->psc_regs->isr_imr.imr, 0);
	out_8(&psc_i2s->psc_regs->command, 3 << 4); /* reset transmitter */
	out_8(&psc_i2s->psc_regs->command, 2 << 4); /* reset receiver */
	out_8(&psc_i2s->psc_regs->command, 1 << 4); /* reset mode */
	out_8(&psc_i2s->psc_regs->command, 4 << 4); /* reset error */

	/* Configure the serial interface mode; defaulting to CODEC8 mode */
	psc_i2s->sicr = MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
			MPC52xx_PSC_SICR_CLKPOL;
	if (of_get_property(op->node, "fsl,cellslave", NULL))
		psc_i2s->sicr |= MPC52xx_PSC_SICR_CELLSLAVE |
				 MPC52xx_PSC_SICR_GENCLK;
	out_be32(&psc_i2s->psc_regs->sicr,
		 psc_i2s->sicr | MPC52xx_PSC_SICR_SIM_CODEC_8);

	/* Check for the codec handle.  If it is not present then we
	 * are done */
	if (!of_get_property(op->node, "codec-handle", NULL))
		return 0;

	/* Set up mode register;
	 * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
	 * Second write: register Normal mode for non loopback
	 */
	out_8(&psc_i2s->psc_regs->mode, 0);
	out_8(&psc_i2s->psc_regs->mode, 0);

	/* Set the TX and RX fifo alarm thresholds */
	out_be16(&psc_i2s->fifo_regs->rfalarm, 0x100);
	out_8(&psc_i2s->fifo_regs->rfcntl, 0x4);
	out_be16(&psc_i2s->fifo_regs->tfalarm, 0x100);
	out_8(&psc_i2s->fifo_regs->tfcntl, 0x7);

	/* Lookup the IRQ numbers */
	psc_i2s->playback.irq =
		bcom_get_task_irq(psc_i2s->playback.bcom_task);
	psc_i2s->capture.irq =
		bcom_get_task_irq(psc_i2s->capture.bcom_task);

	/* Save what we've done so it can be found again later */
	dev_set_drvdata(&op->dev, psc_i2s);

	/* Register the SYSFS files */
	rc = device_create_file(psc_i2s->dev, &dev_attr_status);
	rc = device_create_file(psc_i2s->dev, &dev_attr_capture_overrun);
	rc = device_create_file(psc_i2s->dev, &dev_attr_playback_underrun);
	if (rc)
		dev_info(psc_i2s->dev, "error creating sysfs files\n");

	/* Tell the ASoC OF helpers about it */
	of_snd_soc_register_platform(&psc_i2s_pcm_soc_platform, op->node,
				     &psc_i2s->dai);

	return 0;
}

static int __devexit psc_i2s_of_remove(struct of_device *op)
{
	struct psc_i2s *psc_i2s = dev_get_drvdata(&op->dev);

	dev_dbg(&op->dev, "psc_i2s_remove()\n");

	bcom_gen_bd_rx_release(psc_i2s->capture.bcom_task);
	bcom_gen_bd_tx_release(psc_i2s->playback.bcom_task);

	iounmap(psc_i2s->psc_regs);
	iounmap(psc_i2s->fifo_regs);
	kfree(psc_i2s);
	dev_set_drvdata(&op->dev, NULL);

	return 0;
}

/* Match table for of_platform binding */
static struct of_device_id psc_i2s_match[] __devinitdata = {
	{ .compatible = "fsl,mpc5200-psc-i2s", },
	{}
};
MODULE_DEVICE_TABLE(of, psc_i2s_match);

static struct of_platform_driver psc_i2s_driver = {
	.match_table = psc_i2s_match,
	.probe = psc_i2s_of_probe,
	.remove = __devexit_p(psc_i2s_of_remove),
	.driver = {
		.name = "mpc5200-psc-i2s",
		.owner = THIS_MODULE,
	},
};

/* ---------------------------------------------------------------------
 * Module setup and teardown; simply register the of_platform driver
 * for the PSC in I2S mode.
 */
static int __init psc_i2s_init(void)
{
	return of_register_platform_driver(&psc_i2s_driver);
}
module_init(psc_i2s_init);

static void __exit psc_i2s_exit(void)
{
	of_unregister_platform_driver(&psc_i2s_driver);
}
module_exit(psc_i2s_exit);