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 */
27 static inline enum dma_transfer_direction
snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream * substream)28 snd_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
36 int 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);
38 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
39 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
40 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
41
42 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
43 struct dma_chan *chan);
44 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
45
46 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
47 dma_filter_fn filter_fn, void *filter_data);
48 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
49
50 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
51 void *filter_data);
52 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
53
54 /*
55 * The DAI supports packed transfers, eg 2 16-bit samples in a 32-bit word.
56 * If this flag is set the dmaengine driver won't put any restriction on
57 * the supported sample formats and set the DMA transfer size to undefined.
58 * The DAI driver is responsible to disable any unsupported formats in it's
59 * configuration and catch corner cases that are not already handled in
60 * the ALSA core.
61 */
62 #define SND_DMAENGINE_PCM_DAI_FLAG_PACK BIT(0)
63
64 /**
65 * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
66 * @addr: Address of the DAI data source or destination register.
67 * @addr_width: Width of the DAI data source or destination register.
68 * @maxburst: Maximum number of words(note: words, as in units of the
69 * src_addr_width member, not bytes) that can be send to or received from the
70 * DAI in one burst.
71 * @slave_id: Slave requester id for the DMA channel.
72 * @filter_data: Custom DMA channel filter data, this will usually be used when
73 * requesting the DMA channel.
74 * @chan_name: Custom channel name to use when requesting DMA channel.
75 * @fifo_size: FIFO size of the DAI controller in bytes
76 * @flags: PCM_DAI flags, only SND_DMAENGINE_PCM_DAI_FLAG_PACK for now
77 */
78 struct snd_dmaengine_dai_dma_data {
79 dma_addr_t addr;
80 enum dma_slave_buswidth addr_width;
81 u32 maxburst;
82 unsigned int slave_id;
83 void *filter_data;
84 const char *chan_name;
85 unsigned int fifo_size;
86 unsigned int flags;
87 };
88
89 void snd_dmaengine_pcm_set_config_from_dai_data(
90 const struct snd_pcm_substream *substream,
91 const struct snd_dmaengine_dai_dma_data *dma_data,
92 struct dma_slave_config *config);
93
94
95 /*
96 * Try to request the DMA channel using compat_request_channel or
97 * compat_filter_fn if it couldn't be requested through devicetree.
98 */
99 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
100 /*
101 * Don't try to request the DMA channels through devicetree. This flag only
102 * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
103 */
104 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
105 /*
106 * The PCM is half duplex and the DMA channel is shared between capture and
107 * playback.
108 */
109 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
110 /*
111 * The PCM streams have custom channel names specified.
112 */
113 #define SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME BIT(4)
114
115 /**
116 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
117 * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
118 * PCM substream. Will be called from the PCM drivers hwparams callback.
119 * @compat_request_channel: Callback to request a DMA channel for platforms
120 * which do not use devicetree.
121 * @compat_filter_fn: Will be used as the filter function when requesting a
122 * channel for platforms which do not use devicetree. The filter parameter
123 * will be the DAI's DMA data.
124 * @dma_dev: If set, request DMA channel on this device rather than the DAI
125 * device.
126 * @chan_names: If set, these custom DMA channel names will be requested at
127 * registration time.
128 * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
129 * @prealloc_buffer_size: Size of the preallocated audio buffer.
130 *
131 * Note: If both compat_request_channel and compat_filter_fn are set
132 * compat_request_channel will be used to request the channel and
133 * compat_filter_fn will be ignored. Otherwise the channel will be requested
134 * using dma_request_channel with compat_filter_fn as the filter function.
135 */
136 struct snd_dmaengine_pcm_config {
137 int (*prepare_slave_config)(struct snd_pcm_substream *substream,
138 struct snd_pcm_hw_params *params,
139 struct dma_slave_config *slave_config);
140 struct dma_chan *(*compat_request_channel)(
141 struct snd_soc_pcm_runtime *rtd,
142 struct snd_pcm_substream *substream);
143 dma_filter_fn compat_filter_fn;
144 struct device *dma_dev;
145 const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
146
147 const struct snd_pcm_hardware *pcm_hardware;
148 unsigned int prealloc_buffer_size;
149 };
150
151 int snd_dmaengine_pcm_register(struct device *dev,
152 const struct snd_dmaengine_pcm_config *config,
153 unsigned int flags);
154 void snd_dmaengine_pcm_unregister(struct device *dev);
155
156 int devm_snd_dmaengine_pcm_register(struct device *dev,
157 const struct snd_dmaengine_pcm_config *config,
158 unsigned int flags);
159
160 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
161 struct snd_pcm_hw_params *params,
162 struct dma_slave_config *slave_config);
163
164 #endif
165