Re: [PATCH] ARM64: dts: imx8mm-evk: Assigned clocks for audio plls

From: Tim Harvey
Date: Tue May 19 2020 - 16:29:45 EST


On Wed, Oct 16, 2019 at 3:36 AM S.j. Wang <shengjiu.wang@xxxxxxx> wrote:
>
> Assign clocks and clock-rates for audio plls, that audio
> drivers can utilize them.
>
> Add dai-tdm-slot-num and dai-tdm-slot-width for sound-wm8524,
> that sai driver can generate correct bit clock.
>
> Fixes: 13f3b9fdef6c ("arm64: dts: imx8mm-evk: Enable audio codec wm8524")
> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> ---
> arch/arm64/boot/dts/freescale/imx8mm-evk.dts | 2 ++
> arch/arm64/boot/dts/freescale/imx8mm.dtsi | 8 ++++++--
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-evk.dts b/arch/arm64/boot/dts/freescale/imx8mm-evk.dts
> index f7a15f3904c2..13137451b438 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-evk.dts
> @@ -62,6 +62,8 @@
>
> cpudai: simple-audio-card,cpu {
> sound-dai = <&sai3>;
> + dai-tdm-slot-num = <2>;
> + dai-tdm-slot-width = <32>;
> };
>

Shengjiu,

Can you explain the why dai-tdm-slot-width here is 32? I noticed when
I assigned that for an imx8mm board I'm working on (that uses a
tlv320aic3x codec) I ended up with the clock being off by a factor of
2 (audio playback was 2x too slow).

Best Regards,

Tim