| From 071ccf09cd95cfa486cab493611cb16b7e144294 Mon Sep 17 00:00:00 2001 |
| From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> |
| Date: Thu, 23 Jan 2014 18:39:56 -0800 |
| Subject: ASoC: rsnd: explain SRC bypass mode settings in comment |
| |
| SRC bypass mode is useful for debugging. |
| This patch explains SRC bypass mode settings in comment |
| |
| Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> |
| Signed-off-by: Mark Brown <broonie@linaro.org> |
| (cherry picked from commit 41c6221c39accdc4fe2b0c0fa196b6302b704e57) |
| Signed-off-by: Simon Horman <horms+renesas@verge.net.au> |
| --- |
| sound/soc/sh/rcar/scu.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ |
| 1 file changed, 45 insertions(+) |
| |
| diff --git a/sound/soc/sh/rcar/scu.c b/sound/soc/sh/rcar/scu.c |
| index 872a115cd224..076aa71bc102 100644 |
| --- a/sound/soc/sh/rcar/scu.c |
| +++ b/sound/soc/sh/rcar/scu.c |
| @@ -40,6 +40,51 @@ struct rsnd_scu { |
| * |
| */ |
| |
| +/* |
| + * How to use SRC bypass mode for debugging |
| + * |
| + * SRC has bypass mode, and it is useful for debugging. |
| + * In Gen2 case, |
| + * SRCm_MODE controls whether SRC is used or not |
| + * SSI_MODE0 controls whether SSIU which receives SRC data |
| + * is used or not. |
| + * Both SRCm_MODE/SSI_MODE0 settings are needed if you use SRC, |
| + * but SRC bypass mode needs SSI_MODE0 only. |
| + * |
| + * This driver request |
| + * struct rsnd_scu_platform_info { |
| + * u32 flags; |
| + * u32 convert_rate; |
| + * } |
| + * |
| + * rsnd_scu_hpbif_is_enable() will be true |
| + * if flags had RSND_SCU_USE_HPBIF, |
| + * and it controls whether SSIU is used or not. |
| + * |
| + * rsnd_scu_convert_rate() indicates |
| + * above convert_rate, and it controls |
| + * whether SRC is used or not. |
| + * |
| + * ex) doesn't use SRC |
| + * struct rsnd_scu_platform_info info = { |
| + * .flags = 0, |
| + * .convert_rate = 0, |
| + * }; |
| + * |
| + * ex) uses SRC |
| + * struct rsnd_scu_platform_info info = { |
| + * .flags = RSND_SCU_USE_HPBIF, |
| + * .convert_rate = 48000, |
| + * }; |
| + * |
| + * ex) uses SRC bypass mode |
| + * struct rsnd_scu_platform_info info = { |
| + * .flags = RSND_SCU_USE_HPBIF, |
| + * .convert_rate = 0, |
| + * }; |
| + * |
| + */ |
| + |
| #define rsnd_mod_to_scu(_mod) \ |
| container_of((_mod), struct rsnd_scu, mod) |
| |
| -- |
| 2.1.2 |
| |