Re: [PATCH v4 4/7] arm64: dts: r8a7795: salvator-x: Add DU1 and DU2 external dot clocks

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Laurent,

On Wed, May 10, 2017 at 9:04 AM, Laurent Pinchart
<laurent.pinchart+renesas@ideasonboard.com> wrote:
> The DU1 and DU2 external dot clocks are fixed frequency clock generators
> running at 33MHz.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
>  arch/arm64/boot/dts/renesas/salvator-x.dtsi | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/renesas/salvator-x.dtsi b/arch/arm64/boot/dts/renesas/salvator-x.dtsi
> index 2cd0cce818e7..884c63ebba69 100644
> --- a/arch/arm64/boot/dts/renesas/salvator-x.dtsi
> +++ b/arch/arm64/boot/dts/renesas/salvator-x.dtsi
> @@ -212,6 +212,19 @@
>                 #clock-cells = <0>;
>                 clock-frequency = <24576000>;
>         };
> +
> +       /* External DU dot clocks */
> +       x21_clk: x21-clock {
> +               compatible = "fixed-clock";
> +               #clock-cells = <0>;
> +               clock-frequency = <33000000>;
> +       };
> +
> +       x22_clk: x22-clock {
> +               compatible = "fixed-clock";
> +               #clock-cells = <0>;
> +               clock-frequency = <33000000>;
> +       };
>  };
>
>  &audio_clk_a {
> @@ -238,6 +251,16 @@
>         pinctrl-names = "default";
>         status = "okay";
>
> +       clocks = <&cpg CPG_MOD 724>,
> +                <&cpg CPG_MOD 723>,
> +                <&cpg CPG_MOD 722>,
> +                <&cpg CPG_MOD 721>,
> +                <&cpg CPG_MOD 727>,
> +                <&x21_clk>,
> +                <&x22_clk>;
> +       clock-names = "du.0", "du.1", "du.2", "du.3", "lvds.0",
> +                     "dclkin.1", "dclkin.2";

Another H3 vs. M3-W oddity: DU_DOTCLKIN2 is wired to pin AR7 on H3 SiP,
and AR8 on M3-W SiP.
But crystal X22 is wired to AR7, and AR8 is not connected.
Hence on M3-W, "dclkin.2" is not available, cfr. "NC <M3SiP>" in the schematics.

So either the du clocks and -names should be overridden in
r8a7795-salvator.dtsi to add "dclkin.2", or in r8a7796-salvator.dtsi to
remove it.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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