Root/include/sound/dmaengine_pcm.h

1/*
2 * Copyright (C) 2012, Analog Devices Inc.
3 * Author: Lars-Peter Clausen <lars@metafoo.de>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15#ifndef __SOUND_DMAENGINE_PCM_H__
16#define __SOUND_DMAENGINE_PCM_H__
17
18#include <sound/pcm.h>
19#include <sound/soc.h>
20#include <linux/dmaengine.h>
21
22/**
23 * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
24 * substream
25 * @substream: PCM substream
26 */
27static inline enum dma_transfer_direction
28snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
29{
30    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
31        return DMA_MEM_TO_DEV;
32    else
33        return DMA_DEV_TO_MEM;
34}
35
36int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
37    const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
38int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
39snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
40snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
41
42int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
43    struct dma_chan *chan);
44int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
45
46int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
47    dma_filter_fn filter_fn, void *filter_data);
48int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
49
50struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
51    void *filter_data);
52struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
53
54/**
55 * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
56 * @addr: Address of the DAI data source or destination register.
57 * @addr_width: Width of the DAI data source or destination register.
58 * @maxburst: Maximum number of words(note: words, as in units of the
59 * src_addr_width member, not bytes) that can be send to or received from the
60 * DAI in one burst.
61 * @slave_id: Slave requester id for the DMA channel.
62 * @filter_data: Custom DMA channel filter data, this will usually be used when
63 * requesting the DMA channel.
64 * @chan_name: Custom channel name to use when requesting DMA channel.
65 * @fifo_size: FIFO size of the DAI controller in bytes
66 */
67struct snd_dmaengine_dai_dma_data {
68    dma_addr_t addr;
69    enum dma_slave_buswidth addr_width;
70    u32 maxburst;
71    unsigned int slave_id;
72    void *filter_data;
73    const char *chan_name;
74    unsigned int fifo_size;
75};
76
77void snd_dmaengine_pcm_set_config_from_dai_data(
78    const struct snd_pcm_substream *substream,
79    const struct snd_dmaengine_dai_dma_data *dma_data,
80    struct dma_slave_config *config);
81
82
83/*
84 * Try to request the DMA channel using compat_request_channel or
85 * compat_filter_fn if it couldn't be requested through devicetree.
86 */
87#define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
88/*
89 * Don't try to request the DMA channels through devicetree. This flag only
90 * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
91 */
92#define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
93/*
94 * The platforms dmaengine driver does not support reporting the amount of
95 * bytes that are still left to transfer.
96 */
97#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)
98/*
99 * The PCM is half duplex and the DMA channel is shared between capture and
100 * playback.
101 */
102#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
103/*
104 * The PCM streams have custom channel names specified.
105 */
106#define SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME BIT(4)
107
108/**
109 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
110 * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
111 * PCM substream. Will be called from the PCM drivers hwparams callback.
112 * @compat_request_channel: Callback to request a DMA channel for platforms
113 * which do not use devicetree.
114 * @compat_filter_fn: Will be used as the filter function when requesting a
115 * channel for platforms which do not use devicetree. The filter parameter
116 * will be the DAI's DMA data.
117 * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
118 * @prealloc_buffer_size: Size of the preallocated audio buffer.
119 *
120 * Note: If both compat_request_channel and compat_filter_fn are set
121 * compat_request_channel will be used to request the channel and
122 * compat_filter_fn will be ignored. Otherwise the channel will be requested
123 * using dma_request_channel with compat_filter_fn as the filter function.
124 */
125struct snd_dmaengine_pcm_config {
126    int (*prepare_slave_config)(struct snd_pcm_substream *substream,
127            struct snd_pcm_hw_params *params,
128            struct dma_slave_config *slave_config);
129    struct dma_chan *(*compat_request_channel)(
130            struct snd_soc_pcm_runtime *rtd,
131            struct snd_pcm_substream *substream);
132    dma_filter_fn compat_filter_fn;
133
134    const struct snd_pcm_hardware *pcm_hardware;
135    unsigned int prealloc_buffer_size;
136};
137
138int snd_dmaengine_pcm_register(struct device *dev,
139    const struct snd_dmaengine_pcm_config *config,
140    unsigned int flags);
141void snd_dmaengine_pcm_unregister(struct device *dev);
142
143int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
144    struct snd_pcm_hw_params *params,
145    struct dma_slave_config *slave_config);
146
147#endif
148

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