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

#include <mach/dma-mx1-mx2.h>

#include "imx-ssi.h"

struct imx_pcm_runtime_data {
      int sg_count;
      struct scatterlist *sg_list;
      int period;
      int periods;
      unsigned long dma_addr;
      int dma;
      struct snd_pcm_substream *substream;
      unsigned long offset;
      unsigned long size;
      unsigned long period_cnt;
      void *buf;
      int period_time;
};

/* Called by the DMA framework when a period has elapsed */
static void imx_ssi_dma_progression(int channel, void *data,
                              struct scatterlist *sg)
{
      struct snd_pcm_substream *substream = data;
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;

      if (!sg)
            return;

      runtime = iprtd->substream->runtime;

      iprtd->offset = sg->dma_address - runtime->dma_addr;

      snd_pcm_period_elapsed(iprtd->substream);
}

static void imx_ssi_dma_callback(int channel, void *data)
{
      pr_err("%s shouldn't be called\n", __func__);
}

static void snd_imx_dma_err_callback(int channel, void *data, int err)
{
      pr_err("DMA error callback called\n");

      pr_err("DMA timeout on channel %d -%s%s%s%s\n",
             channel,
             err & IMX_DMA_ERR_BURST ?    " burst" : "",
             err & IMX_DMA_ERR_REQUEST ?  " request" : "",
             err & IMX_DMA_ERR_TRANSFER ? " transfer" : "",
             err & IMX_DMA_ERR_BUFFER ?   " buffer" : "");
}

static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream)
{
      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;
      int ret;

      dma_params = snd_soc_get_dma_data(rtd->dai->cpu_dai, substream);

      iprtd->dma = imx_dma_request_by_prio(DRV_NAME, DMA_PRIO_HIGH);
      if (iprtd->dma < 0) {
            pr_err("Failed to claim the audio DMA\n");
            return -ENODEV;
      }

      ret = imx_dma_setup_handlers(iprtd->dma,
                        imx_ssi_dma_callback,
                        snd_imx_dma_err_callback, substream);
      if (ret)
            goto out;

      ret = imx_dma_setup_progression_handler(iprtd->dma,
                  imx_ssi_dma_progression);
      if (ret) {
            pr_err("Failed to setup the DMA handler\n");
            goto out;
      }

      ret = imx_dma_config_channel(iprtd->dma,
                  IMX_DMA_MEMSIZE_16 | IMX_DMA_TYPE_FIFO,
                  IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
                  dma_params->dma, 1);
      if (ret < 0) {
            pr_err("Cannot configure DMA channel: %d\n", ret);
            goto out;
      }

      imx_dma_config_burstlen(iprtd->dma, dma_params->burstsize * 2);

      return 0;
out:
      imx_dma_free(iprtd->dma);
      return ret;
}

static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *params)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;
      int i;
      unsigned long dma_addr;

      imx_ssi_dma_alloc(substream);

      iprtd->size = params_buffer_bytes(params);
      iprtd->periods = params_periods(params);
      iprtd->period = 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);

      if (iprtd->sg_count != iprtd->periods) {
            kfree(iprtd->sg_list);

            iprtd->sg_list = kcalloc(iprtd->periods + 1,
                        sizeof(struct scatterlist), GFP_KERNEL);
            if (!iprtd->sg_list)
                  return -ENOMEM;
            iprtd->sg_count = iprtd->periods + 1;
      }

      sg_init_table(iprtd->sg_list, iprtd->sg_count);
      dma_addr = runtime->dma_addr;

      for (i = 0; i < iprtd->periods; i++) {
            iprtd->sg_list[i].page_link = 0;
            iprtd->sg_list[i].offset = 0;
            iprtd->sg_list[i].dma_address = dma_addr;
            iprtd->sg_list[i].length = iprtd->period;
            dma_addr += iprtd->period;
      }

      /* close the loop */
      iprtd->sg_list[iprtd->sg_count - 1].offset = 0;
      iprtd->sg_list[iprtd->sg_count - 1].length = 0;
      iprtd->sg_list[iprtd->sg_count - 1].page_link =
                  ((unsigned long) iprtd->sg_list | 0x01) & ~0x02;
      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 >= 0) {
            imx_dma_free(iprtd->dma);
            iprtd->dma = -EINVAL;
      }

      kfree(iprtd->sg_list);
      iprtd->sg_list = NULL;

      return 0;
}

static int snd_imx_pcm_prepare(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct imx_pcm_dma_params *dma_params;
      struct imx_pcm_runtime_data *iprtd = runtime->private_data;
      int err;

      dma_params = snd_soc_get_dma_data(rtd->dai->cpu_dai, substream);

      iprtd->substream = substream;
      iprtd->buf = (unsigned int *)substream->dma_buffer.area;
      iprtd->period_cnt = 0;

      pr_debug("%s: buf: %p period: %d periods: %d\n",
                  __func__, iprtd->buf, iprtd->period, iprtd->periods);

      err = imx_dma_setup_sg(iprtd->dma, iprtd->sg_list, iprtd->sg_count,
                  IMX_DMA_LENGTH_LOOP, dma_params->dma_addr,
                  substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
                  DMA_MODE_WRITE : DMA_MODE_READ);
      if (err)
            return err;

      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:
            imx_dma_enable(iprtd->dma);

            break;

      case SNDRV_PCM_TRIGGER_STOP:
      case SNDRV_PCM_TRIGGER_SUSPEND:
      case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
            imx_dma_disable(iprtd->dma);

            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;

      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 = 16 * 1024,
      .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);
      runtime->private_data = iprtd;

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

      snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
      return 0;
}

static struct snd_pcm_ops imx_pcm_ops = {
      .open       = snd_imx_open,
      .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 imx_soc_platform_dma = {
      .name       = "imx-audio",
      .pcm_ops    = &imx_pcm_ops,
      .pcm_new    = imx_pcm_new,
      .pcm_free   = imx_pcm_free,
};

struct snd_soc_platform *imx_ssi_dma_mx2_init(struct platform_device *pdev,
            struct imx_ssi *ssi)
{
      ssi->dma_params_tx.burstsize = DMA_TXFIFO_BURST;
      ssi->dma_params_rx.burstsize = DMA_RXFIFO_BURST;

      return &imx_soc_platform_dma;
}


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