ALSA: pcm: Introduce copy_user, copy_kernel and fill_silence ops

For supporting the explicit in-kernel copy of PCM buffer data, and
also for further code refactoring, three new PCM ops, copy_user,
copy_kernel and fill_silence, are introduced.  The old copy and
silence ops will be deprecated and removed later once when all callers
are converted.

The copy_kernel ops is the new one, and it's supposed to transfer the
PCM data from the given kernel buffer to the hardware ring-buffer (or
vice-versa depending on the stream direction), while the copy_user ops
is equivalent with the former copy ops, to transfer the data from the
user-space buffer.

The major difference of the new copy_* and fill_silence ops from the
previous ops is that the new ops take bytes instead of frames for size
and position arguments.  It has two merits: first, it allows the
callback implementation often simpler (just call directly memcpy() &
co), and second, it may unify the implementations of both interleaved
and non-interleaved cases, as we'll see in the later patch.

As of this stage, copy_kernel ops isn't referred yet, but only
copy_user is used.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index efc5831f205d..8867ed9e5f56 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -2743,6 +2743,9 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 
 	if (platform->driver->ops) {
 		rtd->ops.ack		= platform->driver->ops->ack;
+		rtd->ops.copy_user	= platform->driver->ops->copy_user;
+		rtd->ops.copy_kernel	= platform->driver->ops->copy_kernel;
+		rtd->ops.fill_silence	= platform->driver->ops->fill_silence;
 		rtd->ops.copy		= platform->driver->ops->copy;
 		rtd->ops.silence	= platform->driver->ops->silence;
 		rtd->ops.page		= platform->driver->ops->page;