linux/sound/soc/soc-generic-dmaengine-pcm.c
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   1/*
   2 *  Copyright (C) 2013, 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#include <linux/module.h>
  16#include <linux/init.h>
  17#include <linux/dmaengine.h>
  18#include <linux/slab.h>
  19#include <sound/pcm.h>
  20#include <sound/pcm_params.h>
  21#include <sound/soc.h>
  22#include <linux/dma-mapping.h>
  23#include <linux/of.h>
  24
  25#include <sound/dmaengine_pcm.h>
  26
  27struct dmaengine_pcm {
  28        struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1];
  29        const struct snd_dmaengine_pcm_config *config;
  30        struct snd_soc_platform platform;
  31        unsigned int flags;
  32};
  33
  34static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
  35{
  36        return container_of(p, struct dmaengine_pcm, platform);
  37}
  38
  39/**
  40 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
  41 * @substream: PCM substream
  42 * @params: hw_params
  43 * @slave_config: DMA slave config to prepare
  44 *
  45 * This function can be used as a generic prepare_slave_config callback for
  46 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
  47 * DAI DMA data. Internally the function will first call
  48 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
  49 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
  50 * remaining fields based on the DAI DMA data.
  51 */
  52int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
  53        struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
  54{
  55        struct snd_soc_pcm_runtime *rtd = substream->private_data;
  56        struct snd_dmaengine_dai_dma_data *dma_data;
  57        int ret;
  58
  59        dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  60
  61        ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
  62        if (ret)
  63                return ret;
  64
  65        snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
  66                slave_config);
  67
  68        return 0;
  69}
  70EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
  71
  72static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
  73        struct snd_pcm_hw_params *params)
  74{
  75        struct snd_soc_pcm_runtime *rtd = substream->private_data;
  76        struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
  77        struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
  78        struct dma_slave_config slave_config;
  79        int ret;
  80
  81        if (pcm->config->prepare_slave_config) {
  82                ret = pcm->config->prepare_slave_config(substream, params,
  83                                &slave_config);
  84                if (ret)
  85                        return ret;
  86
  87                ret = dmaengine_slave_config(chan, &slave_config);
  88                if (ret)
  89                        return ret;
  90        }
  91
  92        return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
  93}
  94
  95static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
  96{
  97        struct snd_soc_pcm_runtime *rtd = substream->private_data;
  98        struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
  99        struct dma_chan *chan = pcm->chan[substream->stream];
 100        int ret;
 101
 102        ret = snd_soc_set_runtime_hwparams(substream,
 103                                pcm->config->pcm_hardware);
 104        if (ret)
 105                return ret;
 106
 107        return snd_dmaengine_pcm_open(substream, chan);
 108}
 109
 110static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
 111        struct snd_pcm_substream *substream)
 112{
 113        if (!pcm->chan[substream->stream])
 114                return NULL;
 115
 116        return pcm->chan[substream->stream]->device->dev;
 117}
 118
 119static void dmaengine_pcm_free(struct snd_pcm *pcm)
 120{
 121        snd_pcm_lib_preallocate_free_for_all(pcm);
 122}
 123
 124static struct dma_chan *dmaengine_pcm_compat_request_channel(
 125        struct snd_soc_pcm_runtime *rtd,
 126        struct snd_pcm_substream *substream)
 127{
 128        struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 129
 130        if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
 131                return pcm->chan[0];
 132
 133        if (pcm->config->compat_request_channel)
 134                return pcm->config->compat_request_channel(rtd, substream);
 135
 136        return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
 137                snd_soc_dai_get_dma_data(rtd->cpu_dai, substream));
 138}
 139
 140static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 141{
 142        struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
 143        const struct snd_dmaengine_pcm_config *config = pcm->config;
 144        struct snd_pcm_substream *substream;
 145        unsigned int i;
 146        int ret;
 147
 148        for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 149                substream = rtd->pcm->streams[i].substream;
 150                if (!substream)
 151                        continue;
 152
 153                if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
 154                        pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
 155                                substream);
 156                }
 157
 158                if (!pcm->chan[i]) {
 159                        dev_err(rtd->platform->dev,
 160                                "Missing dma channel for stream: %d\n", i);
 161                        ret = -EINVAL;
 162                        goto err_free;
 163                }
 164
 165                ret = snd_pcm_lib_preallocate_pages(substream,
 166                                SNDRV_DMA_TYPE_DEV,
 167                                dmaengine_dma_dev(pcm, substream),
 168                                config->prealloc_buffer_size,
 169                                config->pcm_hardware->buffer_bytes_max);
 170                if (ret)
 171                        goto err_free;
 172        }
 173
 174        return 0;
 175
 176err_free:
 177        dmaengine_pcm_free(rtd->pcm);
 178        return ret;
 179}
 180
 181static const struct snd_pcm_ops dmaengine_pcm_ops = {
 182        .open           = dmaengine_pcm_open,
 183        .close          = snd_dmaengine_pcm_close,
 184        .ioctl          = snd_pcm_lib_ioctl,
 185        .hw_params      = dmaengine_pcm_hw_params,
 186        .hw_free        = snd_pcm_lib_free_pages,
 187        .trigger        = snd_dmaengine_pcm_trigger,
 188        .pointer        = snd_dmaengine_pcm_pointer,
 189};
 190
 191static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
 192        .ops            = &dmaengine_pcm_ops,
 193        .pcm_new        = dmaengine_pcm_new,
 194        .pcm_free       = dmaengine_pcm_free,
 195        .probe_order    = SND_SOC_COMP_ORDER_LATE,
 196};
 197
 198static const struct snd_pcm_ops dmaengine_no_residue_pcm_ops = {
 199        .open           = dmaengine_pcm_open,
 200        .close          = snd_dmaengine_pcm_close,
 201        .ioctl          = snd_pcm_lib_ioctl,
 202        .hw_params      = dmaengine_pcm_hw_params,
 203        .hw_free        = snd_pcm_lib_free_pages,
 204        .trigger        = snd_dmaengine_pcm_trigger,
 205        .pointer        = snd_dmaengine_pcm_pointer_no_residue,
 206};
 207
 208static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = {
 209        .ops            = &dmaengine_no_residue_pcm_ops,
 210        .pcm_new        = dmaengine_pcm_new,
 211        .pcm_free       = dmaengine_pcm_free,
 212        .probe_order    = SND_SOC_COMP_ORDER_LATE,
 213};
 214
 215static const char * const dmaengine_pcm_dma_channel_names[] = {
 216        [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
 217        [SNDRV_PCM_STREAM_CAPTURE] = "rx",
 218};
 219
 220static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
 221        struct device *dev)
 222{
 223        unsigned int i;
 224
 225        if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !dev->of_node)
 226                return;
 227
 228        if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
 229                pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
 230                pcm->chan[1] = pcm->chan[0];
 231        } else {
 232                for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 233                        pcm->chan[i] = dma_request_slave_channel(dev,
 234                                        dmaengine_pcm_dma_channel_names[i]);
 235                }
 236        }
 237}
 238
 239/**
 240 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
 241 * @dev: The parent device for the PCM device
 242 * @config: Platform specific PCM configuration
 243 * @flags: Platform specific quirks
 244 */
 245int snd_dmaengine_pcm_register(struct device *dev,
 246        const struct snd_dmaengine_pcm_config *config, unsigned int flags)
 247{
 248        struct dmaengine_pcm *pcm;
 249
 250        pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 251        if (!pcm)
 252                return -ENOMEM;
 253
 254        pcm->config = config;
 255        pcm->flags = flags;
 256
 257        dmaengine_pcm_request_chan_of(pcm, dev);
 258
 259        if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 260                return snd_soc_add_platform(dev, &pcm->platform,
 261                                &dmaengine_no_residue_pcm_platform);
 262        else
 263                return snd_soc_add_platform(dev, &pcm->platform,
 264                                &dmaengine_pcm_platform);
 265}
 266EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
 267
 268/**
 269 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
 270 * @dev: Parent device the PCM was register with
 271 *
 272 * Removes a dmaengine based PCM device previously registered with
 273 * snd_dmaengine_pcm_register.
 274 */
 275void snd_dmaengine_pcm_unregister(struct device *dev)
 276{
 277        struct snd_soc_platform *platform;
 278        struct dmaengine_pcm *pcm;
 279        unsigned int i;
 280
 281        platform = snd_soc_lookup_platform(dev);
 282        if (!platform)
 283                return;
 284
 285        pcm = soc_platform_to_pcm(platform);
 286
 287        for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
 288                if (pcm->chan[i]) {
 289                        dma_release_channel(pcm->chan[i]);
 290                        if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
 291                                break;
 292                }
 293        }
 294
 295        snd_soc_remove_platform(platform);
 296        kfree(pcm);
 297}
 298EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
 299
 300MODULE_LICENSE("GPL");
 301
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