openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Kuninori Morimoto 2014-01-23 18:39:56 -08:00 committed by Mark Brown
parent f80e1c9633
commit 41c6221c39
1 changed files with 45 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
sound/soc/sh/rcar/scu.c
View File

@ -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)