Re: [PATCH 04/18] arm64: dts: renesas: beacon kit: Fix Audio Clock sources

From: Geert Uytterhoeven
Date: Thu Dec 17 2020 - 05:55:21 EST


Hi Adam,

On Sun, Dec 13, 2020 at 7:38 PM Adam Ford <aford173@xxxxxxxxx> wrote:
> The SoC was expecting two clock sources with different frequencies.
> One to support 44.1KHz and one to support 48KHz. With the newly added
> ability to configure the programmably clock, configure both clocks.
>
> Beacause the SoC is expecting a fixed clock/oscillator, it doesn't
> attempt to get and enable the clock for audio_clk_a. The choice to
> use a fixed-factor-clock was due to the fact that it will automatically
> enable the programmable clock frequency without change any code.
>
> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>

Thanks for your patch!

> --- a/arch/arm64/boot/dts/renesas/beacon-renesom-baseboard.dtsi
> +++ b/arch/arm64/boot/dts/renesas/beacon-renesom-baseboard.dtsi
> @@ -250,9 +250,12 @@ ss_ep: endpoint {
> };
>
> &audio_clk_a {
> - clock-frequency = <24576000>;
> - assigned-clocks = <&versaclock6_bb 4>;
> - assigned-clock-rates = <24576000>;
> + /delete-property/ clock-frequency;
> + #clock-cells = <0>;
> + compatible = "fixed-factor-clock";
> + clock-mult = <1>;
> + clock-div = <1>;
> + clocks = <&versaclock6_bb 4>;
> };

Shouldn't you override the clocks property in the rcar_sound node
instead, like is done in several other board DTS files (with cs2000)?

>
> &audio_clk_b {
> @@ -591,7 +594,7 @@ sound_pins: sound {
> };
>
> sound_clk_pins: sound_clk {
> - groups = "audio_clk_a_a";
> + groups = "audio_clk_a_a", "audio_clk_b_a";
> function = "audio_clk";
> };

Yes, this part was definitely missing.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds