Quelle  pxa2xx-pcm-lib.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/dma/pxa-dma.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pxa2xx-lib.h>
#include <sound/dmaengine_pcm.h>

static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
 .info   = SNDRV_PCM_INFO_MMAP |
      SNDRV_PCM_INFO_MMAP_VALID |
      SNDRV_PCM_INFO_INTERLEAVED |
      SNDRV_PCM_INFO_PAUSE |
      SNDRV_PCM_INFO_RESUME,
 .formats  = SNDRV_PCM_FMTBIT_S16_LE |
      SNDRV_PCM_FMTBIT_S24_LE |
      SNDRV_PCM_FMTBIT_S32_LE,
 .period_bytes_min = 32,
 .period_bytes_max = 8192 - 32,
 .periods_min  = 1,
 .periods_max  = 256,
 .buffer_bytes_max = 128 * 1024,
 .fifo_size  = 32,
};

int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *params)
{
 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct snd_dmaengine_dai_dma_data *dma_params;
 struct dma_slave_config config;
 int ret;

 dma_params = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
 if (!dma_params)
  return 0;

 ret = snd_hwparams_to_dma_slave_config(substream, params, &config);
 if (ret)
  return ret;

 snd_dmaengine_pcm_set_config_from_dai_data(substream,
   snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream),
   &config);

 ret = dmaengine_slave_config(chan, &config);
 if (ret)
  return ret;

 return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_hw_params);

int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
 return snd_dmaengine_pcm_trigger(substream, cmd);
}
EXPORT_SYMBOL(pxa2xx_pcm_trigger);

snd_pcm_uframes_t
pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
{
 return snd_dmaengine_pcm_pointer(substream);
}
EXPORT_SYMBOL(pxa2xx_pcm_pointer);

int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
{
 return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_prepare);

int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
{
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_dmaengine_dai_dma_data *dma_params;
 int ret;

 runtime->hw = pxa2xx_pcm_hardware;

 dma_params = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
 if (!dma_params)
  return 0;

 /*
 * For mysterious reasons (and despite what the manual says)
 * playback samples are lost if the DMA count is not a multiple
 * of the DMA burst size.  Let's add a rule to enforce that.
 */
 ret = snd_pcm_hw_constraint_step(runtime, 0,
  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
 if (ret)
  return ret;

 ret = snd_pcm_hw_constraint_step(runtime, 0,
  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
 if (ret)
  return ret;

 ret = snd_pcm_hw_constraint_integer(runtime,
         SNDRV_PCM_HW_PARAM_PERIODS);
 if (ret < 0)
  return ret;

 return snd_dmaengine_pcm_open(
  substream, dma_request_slave_channel(snd_soc_rtd_to_cpu(rtd, 0)->dev,
           dma_params->chan_name));
}
EXPORT_SYMBOL(pxa2xx_pcm_open);

int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
{
 return snd_dmaengine_pcm_close_release_chan(substream);
}
EXPORT_SYMBOL(pxa2xx_pcm_close);

int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm)
{
 size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;

 return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
         pcm->card->dev, size);
}
EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);

int pxa2xx_soc_pcm_new(struct snd_soc_component *component,
         struct snd_soc_pcm_runtime *rtd)
{
 struct snd_card *card = rtd->card->snd_card;
 struct snd_pcm *pcm = rtd->pcm;
 int ret;

 ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 if (ret)
  return ret;

 return pxa2xx_pcm_preallocate_dma_buffer(pcm);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_new);

int pxa2xx_soc_pcm_open(struct snd_soc_component *component,
   struct snd_pcm_substream *substream)
{
 return pxa2xx_pcm_open(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_open);

int pxa2xx_soc_pcm_close(struct snd_soc_component *component,
    struct snd_pcm_substream *substream)
{
 return pxa2xx_pcm_close(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_close);

int pxa2xx_soc_pcm_hw_params(struct snd_soc_component *component,
        struct snd_pcm_substream *substream,
        struct snd_pcm_hw_params *params)
{
 return pxa2xx_pcm_hw_params(substream, params);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_hw_params);

int pxa2xx_soc_pcm_prepare(struct snd_soc_component *component,
      struct snd_pcm_substream *substream)
{
 return pxa2xx_pcm_prepare(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_prepare);

int pxa2xx_soc_pcm_trigger(struct snd_soc_component *component,
      struct snd_pcm_substream *substream, int cmd)
{
 return pxa2xx_pcm_trigger(substream, cmd);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_trigger);

snd_pcm_uframes_t
pxa2xx_soc_pcm_pointer(struct snd_soc_component *component,
         struct snd_pcm_substream *substream)
{
 return pxa2xx_pcm_pointer(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_pointer);

MODULE_AUTHOR("Nicolas Pitre");
MODULE_DESCRIPTION("Intel PXA2xx sound library");
MODULE_LICENSE("GPL");