simple-audio-card,mclk-fs

Commit Message

Daniel Baluta Feb. 22, 2019, 3:16 p.m. UTC

Hello Morimoto-san,

Do you have any plans on adding support for multiple mclk-fs values
in simple-card?

Usually one constant mclk-fs value is not enough because usually codecs
have different value depending on rate.

For example, for wm8524 [1] one can use
mclk-fs = 256 for rates between 8kHz and 96kHz
but it needs to change mclk-fs = 128 for 176.4hHz
and 192kHz.

I am thinking of something like this:

Let me know if this would be a good direction and I will send a patch.

thanks,
Daniel.
[1] https://www.cirrus.com/products/wm8524/

Comments

Kuninori Morimoto Feb. 25, 2019, 1:48 a.m. UTC | #1

Hi Daniel

Thank you for your mail

> Do you have any plans on adding support for multiple mclk-fs values
> in simple-card?
> 
> Usually one constant mclk-fs value is not enough because usually codecs
> have different value depending on rate.
> 
> For example, for wm8524 [1] one can use
> mclk-fs = 256 for rates between 8kHz and 96kHz
> but it needs to change mclk-fs = 128 for 176.4hHz
> and 192kHz.
> 
> I am thinking of something like this:
> 
> --- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> @@ -44,6 +44,8 @@
>                 compatible = "simple-audio-card";
>                 simple-audio-card,name = "wm8524-audio";
>                 simple-audio-card,format = "i2s";
> +               simple-audio-card,lrclk-fs = <8000>, <32000>, <44100>
> <48000>, <96000>, <176400>, <192000>;
> +               simple-audio-card,mclk-fs = <256>, <256>, <256>,
> <256>, <256>, <128>, <128>;
> 
> Let me know if this would be a good direction and I will send a patch.

Yes, actually I have noticed that current mclk-fs is not enough.
Above is nice idea to me. Thank you
One note is that we need to keep compatible

Patch

--- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
@@ -44,6 +44,8 @@ 
                compatible = "simple-audio-card";
                simple-audio-card,name = "wm8524-audio";
                simple-audio-card,format = "i2s";
+               simple-audio-card,lrclk-fs = <8000>, <32000>, <44100>
<48000>, <96000>, <176400>, <192000>;
+               simple-audio-card,mclk-fs = <256>, <256>, <256>,
<256>, <256>, <128>, <128>;