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bf5xx-tdm-pcm.c

/*
 * File:         sound/soc/blackfin/bf5xx-tdm-pcm.c
 * Author:       Barry Song <Barry.Song@analog.com>
 *
 * Created:      Tue June 06 2009
 * Description:  DMA driver for tdm codec
 *
 * Modified:
 *               Copyright 2009 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>

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

#include <asm/dma.h>

#include "bf5xx-tdm-pcm.h"
#include "bf5xx-tdm.h"
#include "bf5xx-sport.h"

#define PCM_BUFFER_MAX  0x10000
#define FRAGMENT_SIZE_MIN  (4*1024)
#define FRAGMENTS_MIN  2
#define FRAGMENTS_MAX  32

static void bf5xx_dma_irq(void *data)
{
      struct snd_pcm_substream *pcm = data;
      snd_pcm_period_elapsed(pcm);
}

static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
      .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
            SNDRV_PCM_INFO_RESUME),
      .formats =          SNDRV_PCM_FMTBIT_S32_LE,
      .rates =            SNDRV_PCM_RATE_48000,
      .channels_min =     2,
      .channels_max =     8,
      .buffer_bytes_max = PCM_BUFFER_MAX,
      .period_bytes_min = FRAGMENT_SIZE_MIN,
      .period_bytes_max = PCM_BUFFER_MAX/2,
      .periods_min =      FRAGMENTS_MIN,
      .periods_max =      FRAGMENTS_MAX,
};

static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
      struct snd_pcm_hw_params *params)
{
      size_t size = bf5xx_pcm_hardware.buffer_bytes_max;
      snd_pcm_lib_malloc_pages(substream, size * 4);

      return 0;
}

static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
      snd_pcm_lib_free_pages(substream);

      return 0;
}

static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct sport_device *sport = runtime->private_data;
      int fragsize_bytes = frames_to_bytes(runtime, runtime->period_size);

      fragsize_bytes /= runtime->channels;
      /* inflate the fragsize to match the dma width of SPORT */
      fragsize_bytes *= 8;

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
            sport_config_tx_dma(sport, runtime->dma_area,
                  runtime->periods, fragsize_bytes);
      } else {
            sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
            sport_config_rx_dma(sport, runtime->dma_area,
                  runtime->periods, fragsize_bytes);
      }

      return 0;
}

static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct sport_device *sport = runtime->private_data;
      int ret = 0;

      switch (cmd) {
      case SNDRV_PCM_TRIGGER_START:
            if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                  sport_tx_start(sport);
            else
                  sport_rx_start(sport);
            break;
      case SNDRV_PCM_TRIGGER_STOP:
      case SNDRV_PCM_TRIGGER_SUSPEND:
      case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
            if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                  sport_tx_stop(sport);
            else
                  sport_rx_stop(sport);
            break;
      default:
            ret = -EINVAL;
      }

      return ret;
}

static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct sport_device *sport = runtime->private_data;
      unsigned int diff;
      snd_pcm_uframes_t frames;

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            diff = sport_curr_offset_tx(sport);
            frames = diff / (8*4); /* 32 bytes per frame */
      } else {
            diff = sport_curr_offset_rx(sport);
            frames = diff / (8*4);
      }
      return frames;
}

static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      int ret = 0;

      snd_soc_set_runtime_hwparams(substream, &bf5xx_pcm_hardware);

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

      if (sport_handle != NULL)
            runtime->private_data = sport_handle;
      else {
            pr_err("sport_handle is NULL\n");
            ret = -ENODEV;
      }
out:
      return ret;
}

static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
      snd_pcm_uframes_t pos, void *buf, snd_pcm_uframes_t count)
{
      unsigned int *src;
      unsigned int *dst;
      int i;

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            src = buf;
            dst = (unsigned int *)substream->runtime->dma_area;

            dst += pos * 8;
            while (count--) {
                  for (i = 0; i < substream->runtime->channels; i++)
                        *(dst + i) = *src++;
                  dst += 8;
            }
      } else {
            src = (unsigned int *)substream->runtime->dma_area;
            dst = buf;

            src += pos * 8;
            while (count--) {
                  for (i = 0; i < substream->runtime->channels; i++)
                        *dst++ = *(src+i);
                  src += 8;
            }
      }

      return 0;
}

static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
      int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
{
      unsigned char *buf = substream->runtime->dma_area;
      buf += pos * 8 * 4;
      memset(buf, '\0', count * 8 * 4);

      return 0;
}


struct snd_pcm_ops bf5xx_pcm_tdm_ops = {
      .open           = bf5xx_pcm_open,
      .ioctl          = snd_pcm_lib_ioctl,
      .hw_params      = bf5xx_pcm_hw_params,
      .hw_free        = bf5xx_pcm_hw_free,
      .prepare        = bf5xx_pcm_prepare,
      .trigger        = bf5xx_pcm_trigger,
      .pointer        = bf5xx_pcm_pointer,
      .copy           = bf5xx_pcm_copy,
      .silence        = bf5xx_pcm_silence,
};

static int bf5xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
      struct snd_pcm_substream *substream = pcm->streams[stream].substream;
      struct snd_dma_buffer *buf = &substream->dma_buffer;
      size_t size = bf5xx_pcm_hardware.buffer_bytes_max;

      buf->dev.type = SNDRV_DMA_TYPE_DEV;
      buf->dev.dev = pcm->card->dev;
      buf->private_data = NULL;
      buf->area = dma_alloc_coherent(pcm->card->dev, size * 4,
            &buf->addr, GFP_KERNEL);
      if (!buf->area) {
            pr_err("Failed to allocate dma memory \
                  Please increase uncached DMA memory region\n");
            return -ENOMEM;
      }
      buf->bytes = size;

      if (stream == SNDRV_PCM_STREAM_PLAYBACK)
            sport_handle->tx_buf = buf->area;
      else
            sport_handle->rx_buf = buf->area;

      return 0;
}

static void bf5xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
      struct snd_pcm_substream *substream;
      struct snd_dma_buffer *buf;
      int stream;

      for (stream = 0; stream < 2; stream++) {
            substream = pcm->streams[stream].substream;
            if (!substream)
                  continue;

            buf = &substream->dma_buffer;
            if (!buf->area)
                  continue;
            dma_free_coherent(NULL, buf->bytes, buf->area, 0);
            buf->area = NULL;
      }
      if (sport_handle)
            sport_done(sport_handle);
}

static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);

static int bf5xx_pcm_tdm_new(struct snd_card *card, struct snd_soc_dai *dai,
      struct snd_pcm *pcm)
{
      int ret = 0;

      if (!card->dev->dma_mask)
            card->dev->dma_mask = &bf5xx_pcm_dmamask;
      if (!card->dev->coherent_dma_mask)
            card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

      if (dai->playback.channels_min) {
            ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                  SNDRV_PCM_STREAM_PLAYBACK);
            if (ret)
                  goto out;
      }

      if (dai->capture.channels_min) {
            ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
                  SNDRV_PCM_STREAM_CAPTURE);
            if (ret)
                  goto out;
      }
out:
      return ret;
}

struct snd_soc_platform bf5xx_tdm_soc_platform = {
      .name           = "bf5xx-audio",
      .pcm_ops        = &bf5xx_pcm_tdm_ops,
      .pcm_new        = bf5xx_pcm_tdm_new,
      .pcm_free       = bf5xx_pcm_free_dma_buffers,
};
EXPORT_SYMBOL_GPL(bf5xx_tdm_soc_platform);

static int __init bfin_pcm_tdm_init(void)
{
      return snd_soc_register_platform(&bf5xx_tdm_soc_platform);
}
module_init(bfin_pcm_tdm_init);

static void __exit bfin_pcm_tdm_exit(void)
{
      snd_soc_unregister_platform(&bf5xx_tdm_soc_platform);
}
module_exit(bfin_pcm_tdm_exit);

MODULE_AUTHOR("Barry Song");
MODULE_DESCRIPTION("ADI Blackfin TDM PCM DMA module");
MODULE_LICENSE("GPL");

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