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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 2 Mar 2020 13:28:13 +0100
Message-ID: <CAMuHMdV9urx-6N4tiaPdkssa6Wu-9HSB4VY-rvCu+8JpfZcBfA@mail.gmail.com>
Subject: Re: [PATCH 8/8] arm64: dts: renesas: salvator: add a connection from
 adv748x codec (HDMI input) to the R-Car SoC
To:     Alex Riesen <alexander.riesen@cetitec.com>,
        Kieran Bingham <kieran.bingham@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        driverdevel <devel@driverdev.osuosl.org>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>
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Hi Alex,

Thanks for your patch!

On Mon, Jan 13, 2020 at 3:24 PM Alex Riesen
<alexander.riesen@cetitec.com> wrote:
> Not sure if all variants of the Salvator board have the HDMI decoder
> chip (the ADV7482) connected to the SSI4 on R-Car SoC, as it is on
> Salvator-X ES1, so the the ADV7482 endpoint and connection definitions
> are placed in the board file.

Both Salvator-X and Salvator-XS have SSI4 wired to the ADV7482.

> I do assume though that all Salvator variants have the CLK_C clock line
> hard-wired to the ADV7482 HDMI decoder, and remove it from the list of
> clocks provided by the R-Car sound system.

Yes, both Salvator-X and Salvator-XS have it wired that way.  But please
see below.

> The I2C wiring is also likely to persist across the variants (similar
> to ak4613, connected to the same interface), so that is in the common
> file.
>
> Signed-off-by: Alexander Riesen <alexander.riesen@cetitec.com>

Below are my comments w.r.t. the board-specific wiring.
I'll defer to the multimedia people for commenting on the audio parts.

BTW, what is the status of the other patches in this series?

> --- a/arch/arm64/boot/dts/renesas/salvator-common.dtsi
> +++ b/arch/arm64/boot/dts/renesas/salvator-common.dtsi
> @@ -322,6 +322,10 @@
>         clock-frequency = <22579200>;
>  };
>
> +&audio_clk_c {
> +       clock-frequency = <12288000>;
> +};

Does the ADV7482 always generate a 12.288 MHz clock signal?
Or is this programmable?

> +
>  &avb {
>         pinctrl-0 = <&avb_pins>;
>         pinctrl-names = "default";
> @@ -471,12 +475,14 @@
>
>                 #address-cells = <1>;
>                 #size-cells = <0>;
> +               #sound-dai-cells = <0>;
>
>                 interrupt-parent = <&gpio6>;
>                 interrupt-names = "intrq1", "intrq2";
>                 interrupts = <30 IRQ_TYPE_LEVEL_LOW>,
>                              <31 IRQ_TYPE_LEVEL_LOW>;
> -
> +               clocks = <&rcar_sound 3>, <&audio_clk_c>;
> +               clock-names = "clk-hdmi-video", "clk-hdmi-i2s-mclk";

The above declares the Audio CLK C to be a clock input of the ADV7482, while
it is an output.
Furthermore, the DT bindings do not document that clocks can be specified.

>                 port@7 {
>                         reg = <7>;
>
> @@ -512,6 +518,14 @@
>                                 remote-endpoint = <&csi20_in>;
>                         };
>                 };
> +
> +               port@c {
> +                       reg = <12>;
> +
> +                       adv7482_i2s: endpoint {
> +                               /* remote-endpoint defined in the board file */
> +                       };
> +               };
>         };
>
>         csa_vdd: adc@7c {
> @@ -686,7 +700,8 @@
>         };
>
>         sound_pins: sound {
> -               groups = "ssi01239_ctrl", "ssi0_data", "ssi1_data_a";
> +               groups = "ssi01239_ctrl", "ssi0_data", "ssi1_data_a",
> +                        "ssi4_data";

Missing "ss4_ctrl", for the SCK4 and WS4 pins.

>                 function = "ssi";
>         };
>
> @@ -735,8 +750,8 @@
>         pinctrl-0 = <&sound_pins &sound_clk_pins>;
>         pinctrl-names = "default";
>
> -       /* Single DAI */
> -       #sound-dai-cells = <0>;
> +       /* multi DAI */
> +       #sound-dai-cells = <1>;
>
>         /* audio_clkout0/1/2/3 */
>         #clock-cells = <1>;
> @@ -760,8 +775,18 @@
>                  <&cpg CPG_MOD 1020>, <&cpg CPG_MOD 1021>,
>                  <&cpg CPG_MOD 1019>, <&cpg CPG_MOD 1018>,
>                  <&audio_clk_a>, <&cs2000>,
> -                <&audio_clk_c>,

Why remove it? This is the list of clock inputs, not outputs.

>                  <&cpg CPG_CORE CPG_AUDIO_CLK_I>;
> +       clock-names = "ssi-all",
> +                     "ssi.9", "ssi.8", "ssi.7", "ssi.6",
> +                     "ssi.5", "ssi.4", "ssi.3", "ssi.2",
> +                     "ssi.1", "ssi.0",
> +                     "src.9", "src.8", "src.7", "src.6",
> +                     "src.5", "src.4", "src.3", "src.2",
> +                     "src.1", "src.0",
> +                     "mix.1", "mix.0",
> +                     "ctu.1", "ctu.0",
> +                     "dvc.0", "dvc.1",
> +                     "clk_a", "clk_b", "clk_i";
>
>         ports {
>                 #address-cells = <1>;
> --
> 2.24.1.508.g91d2dafee0

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