Quelle  tegra_pcm.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * tegra_pcm.c - Tegra PCM driver
 *
 * Author: Stephen Warren <swarren@nvidia.com>
 * Copyright (C) 2010,2012 - NVIDIA, Inc.
 *
 * Based on code copyright/by:
 *
 * Copyright (c) 2009-2010, NVIDIA Corporation.
 * Scott Peterson <speterson@nvidia.com>
 * Vijay Mali <vmali@nvidia.com>
 *
 * Copyright (C) 2010 Google, Inc.
 * Iliyan Malchev <malchev@google.com>
 */

#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include "tegra_pcm.h"

static const struct snd_pcm_hardware tegra_pcm_hardware = {
 .info   = SNDRV_PCM_INFO_MMAP |
      SNDRV_PCM_INFO_MMAP_VALID |
      SNDRV_PCM_INFO_INTERLEAVED,
 .period_bytes_min = 1024,
 .period_bytes_max = PAGE_SIZE,
 .periods_min  = 2,
 .periods_max  = 8,
 .buffer_bytes_max = PAGE_SIZE * 8,
 .fifo_size  = 4,
};

static const struct snd_dmaengine_pcm_config tegra_dmaengine_pcm_config = {
 .pcm_hardware = &tegra_pcm_hardware,
 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
 .prealloc_buffer_size = PAGE_SIZE * 8,
};

int tegra_pcm_platform_register(struct device *dev)
{
 return snd_dmaengine_pcm_register(dev, &tegra_dmaengine_pcm_config, 0);
}
EXPORT_SYMBOL_GPL(tegra_pcm_platform_register);

int devm_tegra_pcm_platform_register(struct device *dev)
{
 return devm_snd_dmaengine_pcm_register(dev, &tegra_dmaengine_pcm_config, 0);
}
EXPORT_SYMBOL_GPL(devm_tegra_pcm_platform_register);

int tegra_pcm_platform_register_with_chan_names(struct device *dev,
    struct snd_dmaengine_pcm_config *config,
    char *txdmachan, char *rxdmachan)
{
 *config = tegra_dmaengine_pcm_config;
 config->dma_dev = dev->parent;
 config->chan_names[0] = txdmachan;
 config->chan_names[1] = rxdmachan;

 return snd_dmaengine_pcm_register(dev, config, 0);
}
EXPORT_SYMBOL_GPL(tegra_pcm_platform_register_with_chan_names);

void tegra_pcm_platform_unregister(struct device *dev)
{
 return snd_dmaengine_pcm_unregister(dev);
}
EXPORT_SYMBOL_GPL(tegra_pcm_platform_unregister);

int tegra_pcm_open(struct snd_soc_component *component,
     struct snd_pcm_substream *substream)
{
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct snd_dmaengine_dai_dma_data *dmap;
 struct dma_chan *chan;
 struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
 int ret;

 if (rtd->dai_link->no_pcm)
  return 0;

 dmap = snd_soc_dai_get_dma_data(cpu_dai, substream);

 /* Set HW params now that initialization is complete */
 snd_soc_set_runtime_hwparams(substream, &tegra_pcm_hardware);

 /* Ensure period size is multiple of 8 */
 ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
      SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 0x8);
 if (ret) {
  dev_err(rtd->dev, "failed to set constraint %d\n", ret);
  return ret;
 }

 chan = dma_request_chan(cpu_dai->dev, dmap->chan_name);
 if (IS_ERR(chan)) {
  dev_err(cpu_dai->dev,
   "dmaengine request slave channel failed! (%s)\n",
   dmap->chan_name);
  return -ENODEV;
 }

 ret = snd_dmaengine_pcm_open(substream, chan);
 if (ret) {
  dev_err(rtd->dev,
   "dmaengine pcm open failed with err %d (%s)\n", ret,
   dmap->chan_name);

  dma_release_channel(chan);

  return ret;
 }

 /* Set wait time to 500ms by default */
 substream->wait_time = 500;

 return 0;
}
EXPORT_SYMBOL_GPL(tegra_pcm_open);

int tegra_pcm_close(struct snd_soc_component *component,
      struct snd_pcm_substream *substream)
{
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);

 if (rtd->dai_link->no_pcm)
  return 0;

 snd_dmaengine_pcm_close_release_chan(substream);

 return 0;
}
EXPORT_SYMBOL_GPL(tegra_pcm_close);

int tegra_pcm_hw_params(struct snd_soc_component *component,
   struct snd_pcm_substream *substream,
   struct snd_pcm_hw_params *params)
{
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct snd_dmaengine_dai_dma_data *dmap;
 struct dma_slave_config slave_config;
 struct dma_chan *chan;
 int ret;

 if (rtd->dai_link->no_pcm)
  return 0;

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

 chan = snd_dmaengine_pcm_get_chan(substream);

 ret = snd_hwparams_to_dma_slave_config(substream, params,
            &slave_config);
 if (ret) {
  dev_err(rtd->dev, "hw params config failed with err %d\n", ret);
  return ret;
 }

 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  slave_config.dst_addr = dmap->addr;
  slave_config.dst_maxburst = 8;
 } else {
  slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  slave_config.src_addr = dmap->addr;
  slave_config.src_maxburst = 8;
 }

 ret = dmaengine_slave_config(chan, &slave_config);
 if (ret < 0) {
  dev_err(rtd->dev, "dma slave config failed with err %d\n", ret);
  return ret;
 }

 return 0;
}
EXPORT_SYMBOL_GPL(tegra_pcm_hw_params);

snd_pcm_uframes_t tegra_pcm_pointer(struct snd_soc_component *component,
        struct snd_pcm_substream *substream)
{
 return snd_dmaengine_pcm_pointer(substream);
}
EXPORT_SYMBOL_GPL(tegra_pcm_pointer);

static int tegra_pcm_dma_allocate(struct device *dev, struct snd_soc_pcm_runtime *rtd,
      size_t size)
{
 struct snd_pcm *pcm = rtd->pcm;
 int ret;

 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 if (ret < 0)
  return ret;

 return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC, dev, size);
}

int tegra_pcm_construct(struct snd_soc_component *component,
   struct snd_soc_pcm_runtime *rtd)
{
 struct device *dev = component->dev;

 /*
 * Fallback for backwards-compatibility with older device trees that
 * have the iommus property in the virtual, top-level "sound" node.
 */
 if (!of_property_present(dev->of_node, "iommus"))
  dev = rtd->card->snd_card->dev;

 return tegra_pcm_dma_allocate(dev, rtd, tegra_pcm_hardware.buffer_bytes_max);
}
EXPORT_SYMBOL_GPL(tegra_pcm_construct);

MODULE_AUTHOR("Stephen Warren ");
MODULE_DESCRIPTION("Tegra PCM ASoC driver");
MODULE_LICENSE("GPL");