static int imx_pcm_prepare(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct mxc_runtime_data *prtd = runtime->private_data;
int ret = 0, channel = 0;
if (prtd->dma_alloc) {
mxc_dma_free(prtd->dma_wchannel);
prtd->dma_alloc = 0;
}
/* only allocate the DMA chn once */
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
#if defined(CONFIG_MXC_ASRC) || defined(CONFIG_MXC_ASRC_MODULE)
if (prtd->asrc_enable == 1) {
struct dma_channel_info info;
mxc_dma_requestbuf_t sdma_request;
info.asrc.channs = runtime->channels;
if (prtd->dma_asrc) {
mxc_dma_free(prtd->dma_asrc);
prtd->dma_asrc = 0;
}
memset(&sdma_request, 0, sizeof(mxc_dma_requestbuf_t));
/* num_of_bytes can be set any value except for zero */
sdma_request.num_of_bytes = 0x40;
channel =
mxc_dma_request_ext(prtd->dma_ch,
"ALSA TX SDMA", &info);
mxc_dma_config(channel, &sdma_request,
1, MXC_DMA_MODE_WRITE);
prtd->dma_asrc = channel;
if (prtd->asrc_index == 0)
prtd->dma_ch = MXC_DMA_ASRC_A_RX;
else if (prtd->asrc_index == 1)
prtd->dma_ch = MXC_DMA_ASRC_B_RX;
else
prtd->dma_ch = MXC_DMA_ASRC_C_RX;
channel =
mxc_dma_request(MXC_DMA_ASRC_A_RX, "ALSA ASRC RX");
} else
channel = mxc_dma_request(prtd->dma_ch, "ALSA TX SDMA");
#else
channel = mxc_dma_request(prtd->dma_ch, "ALSA TX SDMA");
#endif
if (channel < 0) {
pr_err("imx-pcm: error requesting \
a write dma channel\n");
return channel;
}
ret = mxc_dma_callback_set(channel, (mxc_dma_callback_t)
audio_dma_irq, (void *)substream);
} else {
static void mxcmci_setup_dma(struct mxcmci_priv *priv)
{
switch (priv->id) {
case 0:
priv->dma_1bit = mxc_dma_request(MXC_DMA_MMC1_WIDTH_1,
"MMC1-1bit");
priv->dma_4bit = mxc_dma_request(MXC_DMA_MMC1_WIDTH_4,
"MMC1-4bit");
break;
case 1:
priv->dma_1bit = mxc_dma_request(MXC_DMA_MMC2_WIDTH_1,
"MMC2-1bit");
priv->dma_4bit = mxc_dma_request(MXC_DMA_MMC2_WIDTH_4,
"MMC2-4bit");
break;
default:
dev_err(priv->host->parent, "unknown dma-id(%d)\n", priv->id);
return;
}
mxc_dma_callback_set(priv->dma_1bit, mxcmci_dma_irq, (void *)priv);
mxc_dma_callback_set(priv->dma_4bit, mxcmci_dma_irq, (void *)priv);
}
