to_dmadata
pcd = to_dmadata(substream, component);
struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream, component);
u32 c = to_dmadata(substream, component)->ddma_chan;
to_dmadata(substream, component)->pos);
struct au1xpsc_audio_dmadata *pcd = to_dmadata(substream, component);
au1x_pcm_dbdma_free(to_dmadata(substream, component));