aboutsummaryrefslogtreecommitdiff
path: root/sound/soc/soc-generic-dmaengine-pcm.c
blob: 6fd1906af3873aa90b351649c2d0b8afe7152e9d (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
/*
 *  Copyright (C) 2013, Analog Devices Inc.
 *	Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dmaengine.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>

#include <sound/dmaengine_pcm.h>

/*
 * The platforms dmaengine driver does not support reporting the amount of
 * bytes that are still left to transfer.
 */
#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)

struct dmaengine_pcm {
	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
	const struct snd_dmaengine_pcm_config *config;
	struct snd_soc_platform platform;
	unsigned int flags;
};

static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
{
	return container_of(p, struct dmaengine_pcm, platform);
}

static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
	struct snd_pcm_substream *substream)
{
	if (!pcm->chan[substream->stream])
		return NULL;

	return pcm->chan[substream->stream]->device->dev;
}

/**
 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
 * @substream: PCM substream
 * @params: hw_params
 * @slave_config: DMA slave config to prepare
 *
 * This function can be used as a generic prepare_slave_config callback for
 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
 * DAI DMA data. Internally the function will first call
 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
 * remaining fields based on the DAI DMA data.
 */
int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_dmaengine_dai_dma_data *dma_data;
	int ret;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
	if (ret)
		return ret;

	snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
		slave_config);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);

static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
			struct snd_pcm_hw_params *params,
			struct dma_slave_config *slave_config);
	struct dma_slave_config slave_config;
	int ret;

	memset(&slave_config, 0, sizeof(slave_config));

	if (!pcm->config)
		prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
	else
		prepare_slave_config = pcm->config->prepare_slave_config;

	if (prepare_slave_config) {
		ret = prepare_slave_config(substream, params, &slave_config);
		if (ret)
			return ret;

		ret = dmaengine_slave_config(chan, &slave_config);
		if (ret)
			return ret;
	}

	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
}

static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
	struct dma_chan *chan = pcm->chan[substream->stream];
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct dma_slave_caps dma_caps;
	struct snd_pcm_hardware hw;
	u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
			  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
			  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
	int i, ret;

	if (pcm->config && pcm->config->pcm_hardware)
		return snd_soc_set_runtime_hwparams(substream,
				pcm->config->pcm_hardware);

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	memset(&hw, 0, sizeof(hw));
	hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
			SNDRV_PCM_INFO_INTERLEAVED;
	hw.periods_min = 2;
	hw.periods_max = UINT_MAX;
	hw.period_bytes_min = 256;
	hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
	hw.buffer_bytes_max = SIZE_MAX;
	hw.fifo_size = dma_data->fifo_size;

	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
		hw.info |= SNDRV_PCM_INFO_BATCH;

	ret = dma_get_slave_caps(chan, &dma_caps);
	if (ret == 0) {
		if (dma_caps.cmd_pause)
			hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
		if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
			hw.info |= SNDRV_PCM_INFO_BATCH;

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			addr_widths = dma_caps.dst_addr_widths;
		else
			addr_widths = dma_caps.src_addr_widths;
	}

	/*
	 * Prepare formats mask for valid/allowed sample types. If the dma does
	 * not have support for the given physical word size, it needs to be
	 * masked out so user space can not use the format which produces
	 * corrupted audio.
	 * In case the dma driver does not implement the slave_caps the default
	 * assumption is that it supports 1, 2 and 4 bytes widths.
	 */
	for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
		int bits = snd_pcm_format_physical_width(i);

		/* Enable only samples with DMA supported physical widths */
		switch (bits) {
		case 8:
		case 16:
		case 24:
		case 32:
		case 64:
			if (addr_widths & (1 << (bits / 8)))
				hw.formats |= (1LL << i);
			break;
		default:
			/* Unsupported types */
			break;
		}
	}

	return snd_soc_set_runtime_hwparams(substream, &hw);
}

static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct dma_chan *chan = pcm->chan[substream->stream];
	int ret;

	ret = dmaengine_pcm_set_runtime_hwparams(substream);
	if (ret)
		return ret;

	return snd_dmaengine_pcm_open(substream, chan);
}

static struct dma_chan *dmaengine_pcm_compat_request_channel(
	struct snd_soc_pcm_runtime *rtd,
	struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	struct snd_dmaengine_dai_dma_data *dma_data;
	dma_filter_fn fn = NULL;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
		return pcm->chan[0];

	if (pcm->config && pcm->config->compat_request_channel)
		return pcm->config->compat_request_channel(rtd, substream);

	if (pcm->config)
		fn = pcm->config->compat_filter_fn;

	return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
}

static bool dmaengine_pcm_can_report_residue(struct device *dev,
	struct dma_chan *chan)
{
	struct dma_slave_caps dma_caps;
	int ret;

	ret = dma_get_slave_caps(chan, &dma_caps);
	if (ret != 0) {
		dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
			 ret);
		return false;
	}

	if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
		return false;

	return true;
}

static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
	const struct snd_dmaengine_pcm_config *config = pcm->config;
	struct device *dev = rtd->platform->dev;
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct snd_pcm_substream *substream;
	size_t prealloc_buffer_size;
	size_t max_buffer_size;
	unsigned int i;
	int ret;

	if (config && config->prealloc_buffer_size) {
		prealloc_buffer_size = config->prealloc_buffer_size;
		max_buffer_size = config->pcm_hardware->buffer_bytes_max;
	} else {
		prealloc_buffer_size = 512 * 1024;
		max_buffer_size = SIZE_MAX;
	}


	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
		substream = rtd->pcm->streams[i].substream;
		if (!substream)
			continue;

		dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

		if (!pcm->chan[i] &&
		    (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
			pcm->chan[i] = dma_request_slave_channel(dev,
				dma_data->chan_name);

		if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
			pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
				substream);
		}

		if (!pcm->chan[i]) {
			dev_err(rtd->platform->dev,
				"Missing dma channel for stream: %d\n", i);
			return -EINVAL;
		}

		ret = snd_pcm_lib_preallocate_pages(substream,
				SNDRV_DMA_TYPE_DEV_IRAM,
				dmaengine_dma_dev(pcm, substream),
				prealloc_buffer_size,
				max_buffer_size);
		if (ret)
			return ret;

		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
	}

	return 0;
}

static snd_pcm_uframes_t dmaengine_pcm_pointer(
	struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);

	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
		return snd_dmaengine_pcm_pointer_no_residue(substream);
	else
		return snd_dmaengine_pcm_pointer(substream);
}

static const struct snd_pcm_ops dmaengine_pcm_ops = {
	.open		= dmaengine_pcm_open,
	.close		= snd_dmaengine_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= dmaengine_pcm_hw_params,
	.hw_free	= snd_pcm_lib_free_pages,
	.trigger	= snd_dmaengine_pcm_trigger,
	.pointer	= dmaengine_pcm_pointer,
};

static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
	.component_driver = {
		.probe_order = SND_SOC_COMP_ORDER_LATE,
	},
	.ops		= &dmaengine_pcm_ops,
	.pcm_new	= dmaengine_pcm_new,
};

static const char * const dmaengine_pcm_dma_channel_names[] = {
	[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
	[SNDRV_PCM_STREAM_CAPTURE] = "rx",
};

static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
	struct device *dev, const struct snd_dmaengine_pcm_config *config)
{
	unsigned int i;
	const char *name;
	struct dma_chan *chan;

	if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
			   SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
	    !dev->of_node)
		return 0;

	if (config && config->dma_dev) {
		/*
		 * If this warning is seen, it probably means that your Linux
		 * device structure does not match your HW device structure.
		 * It would be best to refactor the Linux device structure to
		 * correctly match the HW structure.
		 */
		dev_warn(dev, "DMA channels sourced from device %s",
			 dev_name(config->dma_dev));
		dev = config->dma_dev;
	}

	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
	     i++) {
		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
			name = "rx-tx";
		else
			name = dmaengine_pcm_dma_channel_names[i];
		if (config && config->chan_names[i])
			name = config->chan_names[i];
		chan = dma_request_slave_channel_reason(dev, name);
		if (IS_ERR(chan)) {
			if (PTR_ERR(chan) == -EPROBE_DEFER)
				return -EPROBE_DEFER;
			pcm->chan[i] = NULL;
		} else {
			pcm->chan[i] = chan;
		}
		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
			break;
	}

	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
		pcm->chan[1] = pcm->chan[0];

	return 0;
}

static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
{
	unsigned int i;

	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
	     i++) {
		if (!pcm->chan[i])
			continue;
		dma_release_channel(pcm->chan[i]);
		if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
			break;
	}
}

/**
 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 * @dev: The parent device for the PCM device
 * @config: Platform specific PCM configuration
 * @flags: Platform specific quirks
 */
int snd_dmaengine_pcm_register(struct device *dev,
	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
{
	struct dmaengine_pcm *pcm;
	int ret;

	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
	if (!pcm)
		return -ENOMEM;

	pcm->config = config;
	pcm->flags = flags;

	ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
	if (ret)
		goto err_free_dma;

	ret = snd_soc_add_platform(dev, &pcm->platform,
		&dmaengine_pcm_platform);
	if (ret)
		goto err_free_dma;

	return 0;

err_free_dma:
	dmaengine_pcm_release_chan(pcm);
	kfree(pcm);
	return ret;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);

/**
 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 * @dev: Parent device the PCM was register with
 *
 * Removes a dmaengine based PCM device previously registered with
 * snd_dmaengine_pcm_register.
 */
void snd_dmaengine_pcm_unregister(struct device *dev)
{
	struct snd_soc_platform *platform;
	struct dmaengine_pcm *pcm;

	platform = snd_soc_lookup_platform(dev);
	if (!platform)
		return;

	pcm = soc_platform_to_pcm(platform);

	snd_soc_remove_platform(platform);
	dmaengine_pcm_release_chan(pcm);
	kfree(pcm);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);

MODULE_LICENSE("GPL");