This patch uses the new pl080 DMA driver for I2S playback and LCD
update. I have tried to be as fiel as possible to the current
behaviour, algorithms and configurations are the same, but using
the new driver. Other modifications:
Playback:
- CHUNK_SIZE is decreased from 42988 to 8188 bytes, it does not
affect normal playback (block size 1024), was tested using
metronome (block size 46080). This change is needed because the
new code commits d-cache range instead of commiting the whole
d-cache, maximum time spent commiting the range should be
limited, CHUNK_SIZE can be decreased even more if necessary.
- pcm_play_dma_start() calls pcm_play_dma_stop() to stop the
channel when it is running (metronome replays the tick sound
without stopping the channel).
- pcm_play_dma_get_peak_buffer(): same as actual SVN function but
returns samples count instead of bytes count.
TODO: AFAIK, actually this function is not used in RB. Not tested,
but probably this function will fail because it returns pointers
to the internal double buffer.
LCD update:
- suppresses lcd_wakeup semaphore and uses yield()
Change-Id: I79b8aa47a941e0dd91847150618f3f7f676c26ef
67b4e7f958