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

On Fri, Jul 30, 2021 at 03:45:50PM +0200, Bert Vermeulen wrote:

From: John Crispin <john@phrozen.org>

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@phrozen.org>
Signed-off-by: Bert Vermeulen <redacted>
---
 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.