static void transfer_done_callback(unsigned long param)
{
int result;
struct ksnd_pcm_streaming *streaming = (struct ksnd_pcm_streaming *)param;
snd_pcm_sframes_t commited_frames;
BUG_ON(streaming->magic != magic_good);
BUG_ON(test_bit(FLAG_BUSY, &streaming->flags) != 1);
// Check if the transfer wasn't stopped by any chance...
if (test_bit(FLAG_STOPPED, &streaming->flags))
return;
// "Commit" playback data
commited_frames = ksnd_pcm_mmap_commit(streaming->playback_handle,
streaming->playback_offset, streaming->playback_frames);
if (commited_frames < 0 ||
(snd_pcm_uframes_t)commited_frames != streaming->playback_frames) {
ERROR("Playback XRUN!\n");
result = ksnd_pcm_prepare(streaming->playback_handle);
if (result != 0) {
ERROR("Can't recover from playback XRUN!\n");
return;
}
}
// "Commit" captured data
commited_frames = ksnd_pcm_mmap_commit(streaming->capture_handle,
streaming->capture_offset, streaming->playback_frames);
if (commited_frames < 0 ||
(snd_pcm_uframes_t)commited_frames != streaming->playback_frames) {
ERROR("Capture XRUN!\n");
result = ksnd_pcm_prepare(streaming->capture_handle);
if (result != 0) {
ERROR("Can't recover from capture XRUN!\n");
return;
}
ksnd_pcm_start(streaming->capture_handle);
}
// Release the lock
clear_bit(FLAG_BUSY, &streaming->flags);
// If another data period has been received in meantime, trigger it not
// (period_captured_callback could be skipped because of transfer in progress)
if (ksnd_pcm_avail_update(streaming->capture_handle) >=
streaming->capture_handle->substream->runtime->period_size)
period_captured_callback(streaming->capture_handle->substream);
}
int ksnd_pcm_mute(ksnd_pcm_t *kpcm, unsigned int push)
{
int err;
snd_pcm_substream_t *substream = kpcm->substream;
if (push == 0)
{
err = ksnd_pcm_prepare(kpcm);
if (err < 0)
return err;
ksnd_pcm_start(kpcm);
}
else
{
_ksnd_pcm_pause(substream, push);
_ksnd_pcm_drop(substream);
}
return 0;
}
int ksnd_pcm_streaming_start(ksnd_pcm_streaming_t *handle,
ksnd_pcm_t *capture, ksnd_pcm_t *playback)
{
int result;
struct ksnd_pcm_streaming *streaming;
const char *fdmac_id[] = { STM_DMAC_ID, NULL };
const char *lb_cap[] = { STM_DMA_CAP_LOW_BW, NULL };
const char *hb_cap[] = { STM_DMA_CAP_HIGH_BW, NULL };
// Allocate and clean streaming structure
streaming = kzalloc(sizeof(*streaming), GFP_KERNEL);
if (streaming == NULL) {
ERROR("Can't get memory for streaming structure!\n");
return -ENOMEM;
}
// Prepare description
streaming->capture_handle = capture;
streaming->playback_handle = playback;
streaming->magic = magic_good;
// Initialize FDMA
streaming->fdma_channel = request_dma_bycap(fdmac_id, lb_cap, "KSOUND_STREAMING");
if (streaming->fdma_channel < 0) {
streaming->fdma_channel = request_dma_bycap(fdmac_id, hb_cap, "KSOUND_STREAMING");
if (streaming->fdma_channel < 0) {
ERROR("Can't allocate FDMA channel!\n");
kfree(streaming);
return -EBUSY;
}
}
dma_params_init(&streaming->fdma_params, MODE_FREERUNNING, STM_DMA_LIST_OPEN);
dma_params_comp_cb(&streaming->fdma_params, transfer_done_callback,
(unsigned long)streaming, STM_DMA_CB_CONTEXT_TASKLET);
dma_params_err_cb(&streaming->fdma_params, transfer_error_callback,
(unsigned long)streaming, STM_DMA_CB_CONTEXT_TASKLET);
dma_params_DIM_1_x_1(&streaming->fdma_params);
result = dma_compile_list(streaming->fdma_channel, &streaming->fdma_params, GFP_KERNEL);
if (result < 0) {
ERROR("Can't compile FDMA parameters!\n");
free_dma(streaming->fdma_channel);
kfree(streaming);
return -EFAULT;
}
// Initialize ALSA
capture->substream->runtime->transfer_ack_end = period_captured_callback;
BUG_ON(capture->substream->runtime->private_data != NULL); // It used to be not used ;-)
capture->substream->runtime->private_data = streaming;
ksnd_pcm_start(capture);
// Return handle
*handle = streaming;
return 0;
}