Re: [PATCH 07/18] ARM: dts: r8a7742: Initial SoC device tree

Geert Uytterhoeven
2020-04-30T13:49:31Z

Hi Prabhakar,

Thanks for your patch!

On Wed, Apr 29, 2020 at 11:58 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> Basic support for the RZ/G1H (R8A7742) SoC. Added placeholders
> for the peripherals supported by the SoC which will be filled up
> by incremental patches.

Please remove the placeholders, as there is nothing that depends on their
presence.

> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>

> --- /dev/null
> +++ b/arch/arm/boot/dts/r8a7742.dtsi
> @@ -0,0 +1,715 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Device Tree Source for the r8a7742 SoC
> + *
> + * Copyright (C) 2020 Renesas Electronics Corp.
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +#include <dt-bindings/clock/r8a7742-cpg-mssr.h>
> +#include <dt-bindings/power/r8a7742-sysc.h>
> +
> +/ {
> + compatible = "renesas,r8a7742";
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + /*
> + * The external audio clocks are configured as 0 Hz fixed frequency
> + * clocks by default.
> + * Boards that provide audio clocks should override them.
> + */
> + audio_clk_a: audio_clk_a {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <0>;
> + };
> +
> + audio_clk_b: audio_clk_b {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <0>;
> + };
> +
> + audio_clk_c: audio_clk_c {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <0>;
> + };
> +
> + /* External CAN clock */
> + can_clk: can {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + /* This value must be overridden by the board. */
> + clock-frequency = <0>;
> + };

Please drop the audio and CAN clocks for now, as they are not used.

> + /* External root clock */
> + extal_clk: extal {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + /* This value must be overridden by the board. */
> + clock-frequency = <0>;
> + };
> +
> + /* External PCIe clock - can be overridden by the board */
> + pcie_bus_clk: pcie_bus {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <0>;
> + };

Please drop the PCI clock for now, as it is not used.

> +
> + /* External SCIF clock */
> + scif_clk: scif {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + /* This value must be overridden by the board. */
> + clock-frequency = <0>;
> + };

This should be used (see below).

> +
> + /* External USB clock - can be overridden by the board */
> + usb_extal_clk: usb_extal {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <48000000>;
> + };
> +
> + cpus {

Please sort nodes by unit-address (if present) per type, or alphabetically.

> + soc {

> + scifa2: serial@e6c60000 {
> + reg = <0 0xe6c60000 0 0x40>;
> + /* placeholder */
> + };

I prefer to see a real node for the serial console, so the system can at
least be boot tested to a console prompt.
Note that this requires adding a minimal board DTS, too.

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