aboutsummaryrefslogtreecommitdiff
path: root/sound/atmel/abdac.c
blob: 4fa1dbd8ee8381e1fbc4260c779cfecdea1d1923 (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
/*
 * Driver for the Atmel on-chip Audio Bitstream DAC (ABDAC)
 *
 * Copyright (C) 2006-2009 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/bitmap.h>
#include <linux/dw_dmac.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/atmel-abdac.h>

/* DAC register offsets */
#define DAC_DATA                                0x0000
#define DAC_CTRL                                0x0008
#define DAC_INT_MASK                            0x000c
#define DAC_INT_EN                              0x0010
#define DAC_INT_DIS                             0x0014
#define DAC_INT_CLR                             0x0018
#define DAC_INT_STATUS                          0x001c

/* Bitfields in CTRL */
#define DAC_SWAP_OFFSET                         30
#define DAC_SWAP_SIZE                           1
#define DAC_EN_OFFSET                           31
#define DAC_EN_SIZE                             1

/* Bitfields in INT_MASK/INT_EN/INT_DIS/INT_STATUS/INT_CLR */
#define DAC_UNDERRUN_OFFSET                     28
#define DAC_UNDERRUN_SIZE                       1
#define DAC_TX_READY_OFFSET                     29
#define DAC_TX_READY_SIZE                       1

/* Bit manipulation macros */
#define DAC_BIT(name)					\
	(1 << DAC_##name##_OFFSET)
#define DAC_BF(name, value)				\
	(((value) & ((1 << DAC_##name##_SIZE) - 1))	\
	 << DAC_##name##_OFFSET)
#define DAC_BFEXT(name, value)				\
	(((value) >> DAC_##name##_OFFSET)		\
	 & ((1 << DAC_##name##_SIZE) - 1))
#define DAC_BFINS(name, value, old)			\
	(((old) & ~(((1 << DAC_##name##_SIZE) - 1)	\
		    << DAC_##name##_OFFSET))		\
	 | DAC_BF(name, value))

/* Register access macros */
#define dac_readl(port, reg)				\
	__raw_readl((port)->regs + DAC_##reg)
#define dac_writel(port, reg, value)			\
	__raw_writel((value), (port)->regs + DAC_##reg)

/*
 * ABDAC supports a maximum of 6 different rates from a generic clock. The
 * generic clock has a power of two divider, which gives 6 steps from 192 kHz
 * to 5112 Hz.
 */
#define MAX_NUM_RATES	6
/* ALSA seems to use rates between 192000 Hz and 5112 Hz. */
#define RATE_MAX	192000
#define RATE_MIN	5112

enum {
	DMA_READY = 0,
};

struct atmel_abdac_dma {
	struct dma_chan		*chan;
	struct dw_cyclic_desc	*cdesc;
};

struct atmel_abdac {
	struct clk				*pclk;
	struct clk				*sample_clk;
	struct platform_device			*pdev;
	struct atmel_abdac_dma			dma;

	struct snd_pcm_hw_constraint_list	constraints_rates;
	struct snd_pcm_substream		*substream;
	struct snd_card				*card;
	struct snd_pcm				*pcm;

	void __iomem				*regs;
	unsigned long				flags;
	unsigned int				rates[MAX_NUM_RATES];
	unsigned int				rates_num;
	int					irq;
};

#define get_dac(card) ((struct atmel_abdac *)(card)->private_data)

/* This function is called by the DMA driver. */
static void atmel_abdac_dma_period_done(void *arg)
{
	struct atmel_abdac *dac = arg;
	snd_pcm_period_elapsed(dac->substream);
}

static int atmel_abdac_prepare_dma(struct atmel_abdac *dac,
		struct snd_pcm_substream *substream,
		enum dma_data_direction direction)
{
	struct dma_chan			*chan = dac->dma.chan;
	struct dw_cyclic_desc		*cdesc;
	struct snd_pcm_runtime		*runtime = substream->runtime;
	unsigned long			buffer_len, period_len;

	/*
	 * We don't do DMA on "complex" transfers, i.e. with
	 * non-halfword-aligned buffers or lengths.
	 */
	if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
		dev_dbg(&dac->pdev->dev, "too complex transfer\n");
		return -EINVAL;
	}

	buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
	period_len = frames_to_bytes(runtime, runtime->period_size);

	cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
			period_len, DMA_MEM_TO_DEV);
	if (IS_ERR(cdesc)) {
		dev_dbg(&dac->pdev->dev, "could not prepare cyclic DMA\n");
		return PTR_ERR(cdesc);
	}

	cdesc->period_callback = atmel_abdac_dma_period_done;
	cdesc->period_callback_param = dac;

	dac->dma.cdesc = cdesc;

	set_bit(DMA_READY, &dac->flags);

	return 0;
}

static struct snd_pcm_hardware atmel_abdac_hw = {
	.info			= (SNDRV_PCM_INFO_MMAP
				  | SNDRV_PCM_INFO_MMAP_VALID
				  | SNDRV_PCM_INFO_INTERLEAVED
				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
				  | SNDRV_PCM_INFO_RESUME
				  | SNDRV_PCM_INFO_PAUSE),
	.formats		= (SNDRV_PCM_FMTBIT_S16_BE),
	.rates			= (SNDRV_PCM_RATE_KNOT),
	.rate_min		= RATE_MIN,
	.rate_max		= RATE_MAX,
	.channels_min		= 2,
	.channels_max		= 2,
	.buffer_bytes_max	= 64 * 4096,
	.period_bytes_min	= 4096,
	.period_bytes_max	= 4096,
	.periods_min		= 6,
	.periods_max		= 64,
};

static int atmel_abdac_open(struct snd_pcm_substream *substream)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);

	dac->substream = substream;
	atmel_abdac_hw.rate_max = dac->rates[dac->rates_num - 1];
	atmel_abdac_hw.rate_min = dac->rates[0];
	substream->runtime->hw = atmel_abdac_hw;

	return snd_pcm_hw_constraint_list(substream->runtime, 0,
			SNDRV_PCM_HW_PARAM_RATE, &dac->constraints_rates);
}

static int atmel_abdac_close(struct snd_pcm_substream *substream)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
	dac->substream = NULL;
	return 0;
}

static int atmel_abdac_hw_params(struct snd_pcm_substream *substream,
		struct snd_pcm_hw_params *hw_params)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
	int retval;

	retval = snd_pcm_lib_malloc_pages(substream,
			params_buffer_bytes(hw_params));
	if (retval < 0)
		return retval;
	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
	if (retval == 1)
		if (test_and_clear_bit(DMA_READY, &dac->flags))
			dw_dma_cyclic_free(dac->dma.chan);

	return retval;
}

static int atmel_abdac_hw_free(struct snd_pcm_substream *substream)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
	if (test_and_clear_bit(DMA_READY, &dac->flags))
		dw_dma_cyclic_free(dac->dma.chan);
	return snd_pcm_lib_free_pages(substream);
}

static int atmel_abdac_prepare(struct snd_pcm_substream *substream)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
	int retval;

	retval = clk_set_rate(dac->sample_clk, 256 * substream->runtime->rate);
	if (retval)
		return retval;

	if (!test_bit(DMA_READY, &dac->flags))
		retval = atmel_abdac_prepare_dma(dac, substream, DMA_TO_DEVICE);

	return retval;
}

static int atmel_abdac_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
	int retval = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
	case SNDRV_PCM_TRIGGER_START:
		clk_enable(dac->sample_clk);
		retval = dw_dma_cyclic_start(dac->dma.chan);
		if (retval)
			goto out;
		dac_writel(dac, CTRL, DAC_BIT(EN));
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
	case SNDRV_PCM_TRIGGER_STOP:
		dw_dma_cyclic_stop(dac->dma.chan);
		dac_writel(dac, DATA, 0);
		dac_writel(dac, CTRL, 0);
		clk_disable(dac->sample_clk);
		break;
	default:
		retval = -EINVAL;
		break;
	}
out:
	return retval;
}

static snd_pcm_uframes_t
atmel_abdac_pointer(struct snd_pcm_substream *substream)
{
	struct atmel_abdac	*dac = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime	*runtime = substream->runtime;
	snd_pcm_uframes_t	frames;
	unsigned long		bytes;

	bytes = dw_dma_get_src_addr(dac->dma.chan);
	bytes -= runtime->dma_addr;

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

	return frames;
}

static irqreturn_t abdac_interrupt(int irq, void *dev_id)
{
	struct atmel_abdac *dac = dev_id;
	u32 status;

	status = dac_readl(dac, INT_STATUS);
	if (status & DAC_BIT(UNDERRUN)) {
		dev_err(&dac->pdev->dev, "underrun detected\n");
		dac_writel(dac, INT_CLR, DAC_BIT(UNDERRUN));
	} else {
		dev_err(&dac->pdev->dev, "spurious interrupt (status=0x%x)\n",
			status);
		dac_writel(dac, INT_CLR, status);
	}

	return IRQ_HANDLED;
}

static struct snd_pcm_ops atmel_abdac_ops = {
	.open		= atmel_abdac_open,
	.close		= atmel_abdac_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= atmel_abdac_hw_params,
	.hw_free	= atmel_abdac_hw_free,
	.prepare	= atmel_abdac_prepare,
	.trigger	= atmel_abdac_trigger,
	.pointer	= atmel_abdac_pointer,
};

static int __devinit atmel_abdac_pcm_new(struct atmel_abdac *dac)
{
	struct snd_pcm_hardware hw = atmel_abdac_hw;
	struct snd_pcm *pcm;
	int retval;

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

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

	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_abdac_ops);

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

	return retval;
}

static bool filter(struct dma_chan *chan, void *slave)
{
	struct dw_dma_slave *dws = slave;

	if (dws->dma_dev == chan->device->dev) {
		chan->private = dws;
		return true;
	} else
		return false;
}

static int set_sample_rates(struct atmel_abdac *dac)
{
	long new_rate = RATE_MAX;
	int retval = -EINVAL;
	int index = 0;

	/* we start at 192 kHz and work our way down to 5112 Hz */
	while (new_rate >= RATE_MIN && index < (MAX_NUM_RATES + 1)) {
		new_rate = clk_round_rate(dac->sample_clk, 256 * new_rate);
		if (new_rate < 0)
			break;
		/* make sure we are below the ABDAC clock */
		if (new_rate <= clk_get_rate(dac->pclk)) {
			dac->rates[index] = new_rate / 256;
			index++;
		}
		/* divide by 256 and then by two to get next rate */
		new_rate /= 256 * 2;
	}

	if (index) {
		int i;

		/* reverse array, smallest go first */
		for (i = 0; i < (index / 2); i++) {
			unsigned int tmp = dac->rates[index - 1 - i];
			dac->rates[index - 1 - i] = dac->rates[i];
			dac->rates[i] = tmp;
		}

		dac->constraints_rates.count = index;
		dac->constraints_rates.list = dac->rates;
		dac->constraints_rates.mask = 0;
		dac->rates_num = index;

		retval = 0;
	}

	return retval;
}

static int __devinit atmel_abdac_probe(struct platform_device *pdev)
{
	struct snd_card		*card;
	struct atmel_abdac	*dac;
	struct resource		*regs;
	struct atmel_abdac_pdata	*pdata;
	struct clk		*pclk;
	struct clk		*sample_clk;
	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 number\n");
		return irq;
	}

	pdata = pdev->dev.platform_data;
	if (!pdata) {
		dev_dbg(&pdev->dev, "no platform data\n");
		return -ENXIO;
	}

	pclk = clk_get(&pdev->dev, "pclk");
	if (IS_ERR(pclk)) {
		dev_dbg(&pdev->dev, "no peripheral clock\n");
		return PTR_ERR(pclk);
	}
	sample_clk = clk_get(&pdev->dev, "sample_clk");
	if (IS_ERR(sample_clk)) {
		dev_dbg(&pdev->dev, "no sample clock\n");
		retval = PTR_ERR(sample_clk);
		goto out_put_pclk;
	}
	clk_enable(pclk);

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

	dac = get_dac(card);

	dac->irq = irq;
	dac->card = card;
	dac->pclk = pclk;
	dac->sample_clk = sample_clk;
	dac->pdev = pdev;

	retval = set_sample_rates(dac);
	if (retval < 0) {
		dev_dbg(&pdev->dev, "could not set supported rates\n");
		goto out_free_card;
	}

	dac->regs = ioremap(regs->start, resource_size(regs));
	if (!dac->regs) {
		dev_dbg(&pdev->dev, "could not remap register memory\n");
		goto out_free_card;
	}

	/* make sure the DAC is silent and disabled */
	dac_writel(dac, DATA, 0);
	dac_writel(dac, CTRL, 0);

	retval = request_irq(irq, abdac_interrupt, 0, "abdac", dac);
	if (retval) {
		dev_dbg(&pdev->dev, "could not request irq\n");
		goto out_unmap_regs;
	}

	snd_card_set_dev(card, &pdev->dev);

	if (pdata->dws.dma_dev) {
		struct dw_dma_slave *dws = &pdata->dws;
		dma_cap_mask_t mask;

		dws->tx_reg = regs->start + DAC_DATA;

		dma_cap_zero(mask);
		dma_cap_set(DMA_SLAVE, mask);

		dac->dma.chan = dma_request_channel(mask, filter, dws);
	}
	if (!pdata->dws.dma_dev || !dac->dma.chan) {
		dev_dbg(&pdev->dev, "DMA not available\n");
		retval = -ENODEV;
		goto out_unset_card_dev;
	}

	strcpy(card->driver, "Atmel ABDAC");
	strcpy(card->shortname, "Atmel ABDAC");
	sprintf(card->longname, "Atmel Audio Bitstream DAC");

	retval = atmel_abdac_pcm_new(dac);
	if (retval) {
		dev_dbg(&pdev->dev, "could not register ABDAC pcm device\n");
		goto out_release_dma;
	}

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

	platform_set_drvdata(pdev, card);

	dev_info(&pdev->dev, "Atmel ABDAC at 0x%p using %s\n",
			dac->regs, dev_name(&dac->dma.chan->dev->device));

	return retval;

out_release_dma:
	dma_release_channel(dac->dma.chan);
	dac->dma.chan = NULL;
out_unset_card_dev:
	snd_card_set_dev(card, NULL);
	free_irq(irq, dac);
out_unmap_regs:
	iounmap(dac->regs);
out_free_card:
	snd_card_free(card);
out_put_sample_clk:
	clk_put(sample_clk);
	clk_disable(pclk);
out_put_pclk:
	clk_put(pclk);
	return retval;
}

#ifdef CONFIG_PM
static int atmel_abdac_suspend(struct platform_device *pdev, pm_message_t msg)
{
	struct snd_card *card = platform_get_drvdata(pdev);
	struct atmel_abdac *dac = card->private_data;

	dw_dma_cyclic_stop(dac->dma.chan);
	clk_disable(dac->sample_clk);
	clk_disable(dac->pclk);

	return 0;
}

static int atmel_abdac_resume(struct platform_device *pdev)
{
	struct snd_card *card = platform_get_drvdata(pdev);
	struct atmel_abdac *dac = card->private_data;

	clk_enable(dac->pclk);
	clk_enable(dac->sample_clk);
	if (test_bit(DMA_READY, &dac->flags))
		dw_dma_cyclic_start(dac->dma.chan);

	return 0;
}
#else
#define atmel_abdac_suspend NULL
#define atmel_abdac_resume NULL
#endif

static int __devexit atmel_abdac_remove(struct platform_device *pdev)
{
	struct snd_card *card = platform_get_drvdata(pdev);
	struct atmel_abdac *dac = get_dac(card);

	clk_put(dac->sample_clk);
	clk_disable(dac->pclk);
	clk_put(dac->pclk);

	dma_release_channel(dac->dma.chan);
	dac->dma.chan = NULL;
	snd_card_set_dev(card, NULL);
	iounmap(dac->regs);
	free_irq(dac->irq, dac);
	snd_card_free(card);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver atmel_abdac_driver = {
	.remove		= __devexit_p(atmel_abdac_remove),
	.driver		= {
		.name	= "atmel_abdac",
	},
	.suspend	= atmel_abdac_suspend,
	.resume		= atmel_abdac_resume,
};

static int __init atmel_abdac_init(void)
{
	return platform_driver_probe(&atmel_abdac_driver,
			atmel_abdac_probe);
}
module_init(atmel_abdac_init);

static void __exit atmel_abdac_exit(void)
{
	platform_driver_unregister(&atmel_abdac_driver);
}
module_exit(atmel_abdac_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Driver for Atmel Audio Bitstream DAC (ABDAC)");
MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");