static snd_pcm_uframes_t
s3c_dma_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct s3c24xx_runtime_data *prtd = runtime->private_data;
unsigned long res;
dma_addr_t src, dst;
pr_debug("Entered %s\n", __func__);
spin_lock(&prtd->lock);
s3c2410_dma_getposition(prtd->params->channel, &src, &dst);
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
res = dst - prtd->dma_start;
else
res = src - prtd->dma_start;
spin_unlock(&prtd->lock);
pr_debug("Pointer %x %x\n", src, dst);
/* we seem to be getting the odd error from the pcm library due
* to out-of-bounds pointers. this is maybe due to the dma engine
* not having loaded the new values for the channel before being
* callled... (todo - fix )
*/
if (res >= snd_pcm_lib_buffer_bytes(substream)) {
if (res == snd_pcm_lib_buffer_bytes(substream))
res = 0;
}
return bytes_to_frames(substream->runtime, res);
}
static u_int audio_get_dma_pos(audio_stream_t *s)
{
int dma_srcpos,dma_dstpos;
audio_buf_t *b = &s->buffers[s->dma_tail];
u_int offset;
if (b->dma_ref) {
s3c2410_dma_getposition(s->dma, &dma_srcpos,&dma_dstpos);
offset = dma_srcpos - b->dma_addr;
if (offset >= s->fragsize)
offset = s->fragsize - 4;
} else if (s->pending_frags) {
offset = b->offset;
} else {
offset = 0;
}
return offset;
}
