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imx-pcm-dma-mx2.c

/*
 * imx-pcm-dma-mx2.c  --  ALSA Soc Audio Layer
 *
 * Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
 *
 * This code is based on code copyrighted by Freescale,
 * Liam Girdwood, Javier Martin and probably others.
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <mach/dma.h>

#include "imx-ssi.h"

00035 struct imx_pcm_runtime_data {
      int period_bytes;
      int periods;
      int dma;
      unsigned long offset;
      unsigned long size;
      void *buf;
      int period_time;
      struct dma_async_tx_descriptor *desc;
      struct dma_chan *dma_chan;
      struct imx_dma_data dma_data;
};

static void audio_dma_irq(void *data)
{
      struct snd_pcm_substream *substream = (struct snd_pcm_substream *)data;
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      iprtd->offset += iprtd->period_bytes;
      iprtd->offset %= iprtd->period_bytes * iprtd->periods;

      snd_pcm_period_elapsed(substream);
}

static bool filter(struct dma_chan *chan, void *param)
{
      struct imx_pcm_runtime_data *iprtd = param;

      if (!imx_dma_is_general_purpose(chan))
            return false;

        chan->private = &iprtd->dma_data;

        return true;
}

static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *params)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct imx_pcm_dma_params *dma_params;
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;
      struct dma_slave_config slave_config;
      dma_cap_mask_t mask;
      enum dma_slave_buswidth buswidth;
      int ret;

      dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

      iprtd->dma_data.peripheral_type = IMX_DMATYPE_SSI;
      iprtd->dma_data.priority = DMA_PRIO_HIGH;
      iprtd->dma_data.dma_request = dma_params->dma;

      /* Try to grab a DMA channel */
      dma_cap_zero(mask);
      dma_cap_set(DMA_SLAVE, mask);
      iprtd->dma_chan = dma_request_channel(mask, filter, iprtd);
      if (!iprtd->dma_chan)
            return -EINVAL;

      switch (params_format(params)) {
      case SNDRV_PCM_FORMAT_S16_LE:
            buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
            break;
      case SNDRV_PCM_FORMAT_S20_3LE:
      case SNDRV_PCM_FORMAT_S24_LE:
            buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
            break;
      default:
            return 0;
      }

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            slave_config.direction = DMA_TO_DEVICE;
            slave_config.dst_addr = dma_params->dma_addr;
            slave_config.dst_addr_width = buswidth;
            slave_config.dst_maxburst = dma_params->burstsize;
      } else {
            slave_config.direction = DMA_FROM_DEVICE;
            slave_config.src_addr = dma_params->dma_addr;
            slave_config.src_addr_width = buswidth;
            slave_config.src_maxburst = dma_params->burstsize;
      }

      ret = dmaengine_slave_config(iprtd->dma_chan, &slave_config);
      if (ret)
            return ret;

      return 0;
}

static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *params)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;
      unsigned long dma_addr;
      struct dma_chan *chan;
      struct imx_pcm_dma_params *dma_params;
      int ret;

      dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
      ret = imx_ssi_dma_alloc(substream, params);
      if (ret)
            return ret;
      chan = iprtd->dma_chan;

      iprtd->size = params_buffer_bytes(params);
      iprtd->periods = params_periods(params);
      iprtd->period_bytes = params_period_bytes(params);
      iprtd->offset = 0;
      iprtd->period_time = HZ / (params_rate(params) /
                  params_period_size(params));

      snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

      dma_addr = runtime->dma_addr;

      iprtd->buf = (unsigned int *)substream->dma_buffer.area;

      iprtd->desc = chan->device->device_prep_dma_cyclic(chan, dma_addr,
                  iprtd->period_bytes * iprtd->periods,
                  iprtd->period_bytes,
                  substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
                  DMA_TO_DEVICE : DMA_FROM_DEVICE);
      if (!iprtd->desc) {
            dev_err(&chan->dev->device, "cannot prepare slave dma\n");
            return -EINVAL;
      }

      iprtd->desc->callback = audio_dma_irq;
      iprtd->desc->callback_param = substream;

      return 0;
}

static int snd_imx_pcm_hw_free(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      if (iprtd->dma_chan) {
            dma_release_channel(iprtd->dma_chan);
            iprtd->dma_chan = NULL;
      }

      return 0;
}

static int snd_imx_pcm_prepare(struct snd_pcm_substream *substream)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct imx_pcm_dma_params *dma_params;

      dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

      return 0;
}

static int snd_imx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      switch (cmd) {
      case SNDRV_PCM_TRIGGER_START:
      case SNDRV_PCM_TRIGGER_RESUME:
      case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
            dmaengine_submit(iprtd->desc);

            break;

      case SNDRV_PCM_TRIGGER_STOP:
      case SNDRV_PCM_TRIGGER_SUSPEND:
      case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
            dmaengine_terminate_all(iprtd->dma_chan);

            break;
      default:
            return -EINVAL;
      }

      return 0;
}

static snd_pcm_uframes_t snd_imx_pcm_pointer(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      pr_debug("%s: %ld %ld\n", __func__, iprtd->offset,
                  bytes_to_frames(substream->runtime, iprtd->offset));

      return bytes_to_frames(substream->runtime, iprtd->offset);
}

static struct snd_pcm_hardware snd_imx_hardware = {
      .info = SNDRV_PCM_INFO_INTERLEAVED |
            SNDRV_PCM_INFO_BLOCK_TRANSFER |
            SNDRV_PCM_INFO_MMAP |
            SNDRV_PCM_INFO_MMAP_VALID |
            SNDRV_PCM_INFO_PAUSE |
            SNDRV_PCM_INFO_RESUME,
      .formats = SNDRV_PCM_FMTBIT_S16_LE,
      .rate_min = 8000,
      .channels_min = 2,
      .channels_max = 2,
      .buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
      .period_bytes_min = 128,
      .period_bytes_max = 65535, /* Limited by SDMA engine */
      .periods_min = 2,
      .periods_max = 255,
      .fifo_size = 0,
};

static int snd_imx_open(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd;
      int ret;

      iprtd = kzalloc(sizeof(*iprtd), GFP_KERNEL);
      if (iprtd == NULL)
            return -ENOMEM;
      runtime->private_data = iprtd;

      ret = snd_pcm_hw_constraint_integer(substream->runtime,
                  SNDRV_PCM_HW_PARAM_PERIODS);
      if (ret < 0) {
            kfree(iprtd);
            return ret;
      }

      snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);

      return 0;
}

static int snd_imx_close(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      kfree(iprtd);

      return 0;
}

static struct snd_pcm_ops imx_pcm_ops = {
      .open       = snd_imx_open,
      .close            = snd_imx_close,
      .ioctl            = snd_pcm_lib_ioctl,
      .hw_params  = snd_imx_pcm_hw_params,
      .hw_free    = snd_imx_pcm_hw_free,
      .prepare    = snd_imx_pcm_prepare,
      .trigger    = snd_imx_pcm_trigger,
      .pointer    = snd_imx_pcm_pointer,
      .mmap       = snd_imx_pcm_mmap,
};

static struct snd_soc_platform_driver imx_soc_platform_mx2 = {
      .ops        = &imx_pcm_ops,
      .pcm_new    = imx_pcm_new,
      .pcm_free   = imx_pcm_free,
};

static int __devinit imx_soc_platform_probe(struct platform_device *pdev)
{
      return snd_soc_register_platform(&pdev->dev, &imx_soc_platform_mx2);
}

static int __devexit imx_soc_platform_remove(struct platform_device *pdev)
{
      snd_soc_unregister_platform(&pdev->dev);
      return 0;
}

static struct platform_driver imx_pcm_driver = {
      .driver = {
                  .name = "imx-pcm-audio",
                  .owner = THIS_MODULE,
      },
      .probe = imx_soc_platform_probe,
      .remove = __devexit_p(imx_soc_platform_remove),
};

static int __init snd_imx_pcm_init(void)
{
      return platform_driver_register(&imx_pcm_driver);
}
module_init(snd_imx_pcm_init);

static void __exit snd_imx_pcm_exit(void)
{
      platform_driver_unregister(&imx_pcm_driver);
}
module_exit(snd_imx_pcm_exit);

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