From: Kuninori Morimoto Date: Fri, 9 Jun 2017 00:34:09 +0000 (+0000) Subject: ASoC: rsnd: add detail explanation of L/R conversion timing X-Git-Tag: v4.13-rc1~142^2~1^2~4^2~9 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8cce431aa26ef24a4d4b820301ac73bf55df7a5e;p=karo-tx-linux.git 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: Kuninori Morimoto Signed-off-by: Mark Brown --- diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c index 7c68f9d4a0ed..1bf261d677b7 100644 --- a/sound/soc/sh/rcar/core.c +++ b/sound/soc/sh/rcar/core.c @@ -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);