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Commit 8cce431a authored by Kuninori Morimoto's avatar Kuninori Morimoto Committed by Mark Brown
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ASoC: rsnd: add detail explanation of L/R conversion timing 



Renesas Sound device *Hardware* L/R and Linux *Software* L/R are
inverted. Because of this background, it needs to convert L/R.
Then, DVC needs *Hardware* L/R, and Linux needs *Software* L/R.
Because Playback/Capture needs different timing, and there is no
explanation about it on source code / git log, this patch adds it.

Signed-off-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent a97a06c7

sound/soc/sh/rcar/core.c

+18 −0
Original line number Diff line number Diff line
@@ -310,6 +310,24 @@ u32 rsnd_get_dalign(struct rsnd_mod *mod, struct rsnd_dai_stream *io) 
	u32 val = 0x76543210;

	u32 mask = ~0;



	/*

	 * *Hardware* L/R and *Software* L/R are inverted.

	 * We need to care about inversion timing to control

	 * Playback/Capture correctly.

	 * The point is [DVC] needs *Hardware* L/R, [MEM] needs *Software* L/R

	 *

	 * sL/R : software L/R

	 * hL/R : hardware L/R

	 * (*)  : conversion timing

	 *

	 * Playback

	 *	     sL/R (*) hL/R     hL/R     hL/R      hL/R     hL/R

	 *	[MEM] -> [SRC] -> [DVC] -> [CMD] -> [SSIU] -> [SSI] -> codec

	 *

	 * Capture

	 *	     hL/R     hL/R      hL/R     hL/R     hL/R (*) sL/R

	 *	codec -> [SSI] -> [SSIU] -> [SRC] -> [DVC] -> [CMD] -> [MEM]

	 */

	if (rsnd_io_is_play(io)) {

		struct rsnd_mod *src = rsnd_io_to_mod_src(io);