Re: [PATCH 3/5] ARM: dts: Add basic support for EcoNet EN7523

[Mark Rutland]

On Fri, Jul 30, 2021 at 03:45:50PM +0200, Bert Vermeulen wrote:
> From: John Crispin <john@xxxxxxxxxxx>
> 
> Add basic support for EcoNet EN7523, enough for booting to console.
> 
> The UART is basically 8250-compatible, except for the clock selection.
> A clock-frequency value is synthesized to get this to run at 115200 bps.
> 
> Signed-off-by: John Crispin <john@xxxxxxxxxxx>
> Signed-off-by: Bert Vermeulen <bert@xxxxxxxx>
> ---
>  arch/arm/boot/dts/Makefile       |   2 +
>  arch/arm/boot/dts/en7523-evb.dts |  17 ++++
>  arch/arm/boot/dts/en7523.dtsi    | 128 +++++++++++++++++++++++++++++++
>  3 files changed, 147 insertions(+)
>  create mode 100644 arch/arm/boot/dts/en7523-evb.dts
>  create mode 100644 arch/arm/boot/dts/en7523.dtsi

[...]

> +	gic: interrupt-controller@09000000 {
> +		compatible = "arm,gic-v3";
> +		interrupt-controller;
> +		#interrupt-cells = <3>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		reg = <0x09000000 0x20000>,
> +			  <0x09080000 0x80000>;
> +		interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_LOW>;
> +
> +		its: gic-its@09020000 {
> +			compatible = "arm,gic-v3-its";
> +			msi-controller;
> +			#msi-cell = <1>;
> +			reg = <0x090200000 0x20000>;
> +		};
> +	};
> +
> +	timer {
> +		compatible = "arm,armv8-timer";

This should be "arm,armv7-timer".

> +		interrupt-parent = <&gic>;
> +		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
> +			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;

GICv3 doesn't have a cpumask in its PPI description, so the
GIC_CPU_MASK_SIMPLE() bits should be removed.

> +		clock-frequency = <25000000>;

Please have your FW configure CNTFRQ on each CPU; the clock-frequency
property in the DT is a workaround for broken FW, and it's *vastly*
preferable for FW to configure this correctly (e.g. as it means VMs
should "just work").

Thanks,
Mark.