Re: [PATCH 3/4] arm64: dts: rockchip: Add base DT for rk3528 SoC

["Heiko Stübner" <heiko@sntech.de>]

Am Sonntag, 4. August 2024, 15:25:47 CEST schrieb Dragan Simic:
> On 2024-08-04 15:20, Yao Zi wrote:
> > On Sun, Aug 04, 2024 at 12:05:11PM +0200, Krzysztof Kozlowski wrote:
> >> On 03/08/2024 14:55, Yao Zi wrote:
> >> > This initial device tree describes CPU, interrupts and UART on the chip
> >> > and is able to boot into basic kernel with only UART. Cache information
> >> > is omitted for now as there is no precise documentation. Support for
> >> > other features will be added later.
> >> >
> >> > Signed-off-by: Yao Zi <ziyao@disroot.org>
> >> > ---
> >> >  arch/arm64/boot/dts/rockchip/rk3528.dtsi | 182 +++++++++++++++++++++++
> >> >  1 file changed, 182 insertions(+)
> >> >  create mode 100644 arch/arm64/boot/dts/rockchip/rk3528.dtsi
> >> >
> >> > diff --git a/arch/arm64/boot/dts/rockchip/rk3528.dtsi b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
> >> > new file mode 100644
> >> > index 000000000000..77687d9e7e80
> >> > --- /dev/null
> >> > +++ b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
> >> > @@ -0,0 +1,182 @@
> >> > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> >> > +/*
> >> > + * Copyright (c) 2022 Rockchip Electronics Co., Ltd.
> >> > + * Copyright (c) 2024 Yao Zi <ziyao@disroot.org>
> >> > + */
> >> > +
> >> > +#include <dt-bindings/interrupt-controller/arm-gic.h>
> >> > +#include <dt-bindings/interrupt-controller/irq.h>
> >> > +
> >> > +/ {
> >> > +	compatible = "rockchip,rk3528";
> >> > +
> >> > +	interrupt-parent = <&gic>;
> >> > +	#address-cells = <2>;
> >> > +	#size-cells = <2>;
> >> > +
> >> > +	aliases {
> >> > +		serial0 = &uart0;
> >> > +		serial1 = &uart1;
> >> > +		serial2 = &uart2;
> >> > +		serial3 = &uart3;
> >> > +		serial4 = &uart4;
> >> > +		serial5 = &uart5;
> >> > +		serial6 = &uart6;
> >> > +		serial7 = &uart7;
> >> > +	};
> >> > +
> >> > +	cpus {
> >> > +		#address-cells = <1>;
> >> > +		#size-cells = <0>;
> >> > +
> >> > +		cpu-map {
> >> > +			cluster0 {
> >> > +				core0 {
> >> > +					cpu = <&cpu0>;
> >> > +				};
> >> > +				core1 {
> >> > +					cpu = <&cpu1>;
> >> > +				};
> >> > +				core2 {
> >> > +					cpu = <&cpu2>;
> >> > +				};
> >> > +				core3 {
> >> > +					cpu = <&cpu3>;
> >> > +				};
> >> > +			};
> >> > +		};
> >> > +
> >> > +		cpu0: cpu@0 {
> >> > +			device_type = "cpu";
> >> > +			compatible = "arm,cortex-a53";
> >> > +			reg = <0x0>;
> >> > +			enable-method = "psci";
> >> > +		};
> >> > +
> >> > +		cpu1: cpu@1 {
> >> > +			device_type = "cpu";
> >> > +			compatible = "arm,cortex-a53";
> >> > +			reg = <0x1>;
> >> > +			enable-method = "psci";
> >> > +		};
> >> > +
> >> > +		cpu2: cpu@2 {
> >> > +			device_type = "cpu";
> >> > +			compatible = "arm,cortex-a53";
> >> > +			reg = <0x2>;
> >> > +			enable-method = "psci";
> >> > +		};
> >> > +
> >> > +		cpu3: cpu@3 {
> >> > +			device_type = "cpu";
> >> > +			compatible = "arm,cortex-a53";
> >> > +			reg = <0x3>;
> >> > +			enable-method = "psci";
> >> > +		};
> >> > +	};
> >> > +
> >> > +	psci {
> >> > +		compatible = "arm,psci-1.0", "arm,psci-0.2";
> >> > +		method = "smc";
> >> > +	};
> >> > +
> >> > +	timer {
> >> > +		compatible = "arm,armv8-timer";
> >> > +		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)>;
> >> > +	};
> >> > +
> >> > +	xin24m: xin24m {
> >> 
> >> Please use name for all fixed clocks which matches current format
> >> recommendation: 'clock-([0-9]+|[a-z0-9-]+)+'
> > 
> > Will be fixed in next revision.
> 
> Hmm, why should we apply that rule to the xin24m clock, which is
> named exactly like that everywhere else in Rockchip SoC dtsi files?
> It's much better to remain consistent.

bindings or how we write devicetrees evolve over time ... similarly the
xin24m name comes from more than 10 years ago.

We also name all those regulator nodes regulator-foo now, which in turn
automatically does enforce a nice sorting rule to keep all the regulators
around the same area ;-)

So I don't see a problem of going with xin24m: clock-xin24m {}


Heiko

> 
> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/clock/fixed-clock.yaml?h=v6.11-rc1
> >> 
> >> > +		compatible = "fixed-clock";
> >> > +		#clock-cells = <0>;
> >> > +		clock-frequency = <24000000>;
> >> > +		clock-output-names = "xin24m";
> >> > +	};
> >> > +
> >> > +	gic: interrupt-controller@fed01000 {
> >> 
> >> Why this all is outside of SoC?
> > 
> > Just as Heiko says, device tree for all other Rockchip SoCs don't have
> > a "soc" node. I didn't know why before but just follow the style.
> > 
> > If you prefer add a soc node, I am willing to.
>