1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com
4 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
5 */
6
7#include <linux/device.h>
8#include <linux/module.h>
9#include <sound/core.h>
10#include <sound/pcm.h>
11#include <sound/pcm_params.h>
12#include <sound/soc.h>
13#include <sound/dmaengine_pcm.h>
14
15#include "sdma-pcm.h"
16
17static const struct snd_pcm_hardware sdma_pcm_hardware = {
18 .info = SNDRV_PCM_INFO_MMAP |
19 SNDRV_PCM_INFO_MMAP_VALID |
20 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME |
21 SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
22 SNDRV_PCM_INFO_INTERLEAVED,
23 .period_bytes_min = 32,
24 .period_bytes_max = 64 * 1024,
25 .buffer_bytes_max = 128 * 1024,
26 .periods_min = 2,
27 .periods_max = 255,
28};
29
30static const struct snd_dmaengine_pcm_config sdma_dmaengine_pcm_config = {
31 .pcm_hardware = &sdma_pcm_hardware,
32 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
33 .prealloc_buffer_size = 128 * 1024,
34};
35
36int sdma_pcm_platform_register(struct device *dev,
37 char *txdmachan, char *rxdmachan)
38{
39 struct snd_dmaengine_pcm_config *config;
40 unsigned int flags = 0;
41
42 /* Standard names for the directions: 'tx' and 'rx' */
43 if (!txdmachan && !rxdmachan)
44 return devm_snd_dmaengine_pcm_register(dev,
45 config: &sdma_dmaengine_pcm_config, flags: 0);
46
47 config = devm_kzalloc(dev, size: sizeof(*config), GFP_KERNEL);
48 if (!config)
49 return -ENOMEM;
50
51 *config = sdma_dmaengine_pcm_config;
52
53 if (!txdmachan || !rxdmachan) {
54 /* One direction only PCM */
55 flags |= SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX;
56 if (!txdmachan) {
57 txdmachan = rxdmachan;
58 rxdmachan = NULL;
59 }
60 }
61
62 config->chan_names[0] = txdmachan;
63 config->chan_names[1] = rxdmachan;
64
65 return devm_snd_dmaengine_pcm_register(dev, config, flags);
66}
67EXPORT_SYMBOL_GPL(sdma_pcm_platform_register);
68
69MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
70MODULE_DESCRIPTION("sDMA PCM ASoC platform driver");
71MODULE_LICENSE("GPL v2");
72

source code of linux/sound/soc/ti/sdma-pcm.c