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

["Heiko Stübner" <heiko@sntech.de>]

Am Sonntag, 4. August 2024, 15:59:19 CEST schrieb Dragan Simic:
> On 2024-08-04 15:44, Heiko Stübner wrote:
> > 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 {}
> 
> I agree that using "clock-xin24m" makes more sense in general, but the
> trouble is that we can't rename the already existing instances of 
> "xin24m",
> because that has become part of the ABI.  Thus, I'm not sure that 
> breaking
> away from the legacy brings benefits in this particular case.

In the regulator case, we have _new_ boards using the new _node_-names
but I don't see any renaming of old boards and also don't think we should.

But that still does not keep us from using the nicer naming convention in
new boards ;-) .


Same with xin24m. We're talking only about the node-name here. The
phandle stays the same and also the actual clock name stays the same and
really only the actual node name you need to look for in /proc/device-tree
changes ;-) .

So I don't see the need to go about changing all the old socs, but new
additions should use improved naming conventions.

xin24m: clock-xin24m {
	compatible = "fixed-clock";
	#clock-cells = <0>;
	clock-frequency = <24000000>;
	clock-output-names = "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.
> >> 
> > 
> > 
> > 
> > 
> > 
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>