Subject: [PATCH v3 07/10] ARM: dts: Add initial device tree support for Exynos5420

From: [email-masked] (Tomasz Figa)
Date: Tue, 18 Jun 2013 09:36:55 +0200

On Tuesday 18 of June 2013 09:51:14 Chander Kashyap wrote:
> On 17 June 2013 17:14, Tomasz Figa <[email-masked]> wrote:
> > --
> > Tomasz Figa
> > Linux Kernel Developer
> > Samsung R&D Institute Poland
> > Samsung Electronics
> > 
> > On Monday 17 of June 2013 16:30:32 Chander Kashyap wrote:
> >> Add initial device tree nodes for Exynos5420 SoC and SMDK5420 board.
> >> 
> >> Signed-off-by: Chander Kashyap <[email-masked]>
> >> ---
> >> 
> >>  arch/arm/boot/dts/Makefile                |    1 +
> >>  arch/arm/boot/dts/exynos5420-smdk5420.dts |   33 +++++++++
> >>  arch/arm/boot/dts/exynos5420.dtsi         |  103
> >> 
> >> +++++++++++++++++++++++++++++ 3 files changed, 137 insertions(+)
> >> 
> >>  create mode 100644 arch/arm/boot/dts/exynos5420-smdk5420.dts
> >>  create mode 100644 arch/arm/boot/dts/exynos5420.dtsi
> >> 
> >> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> >> index f0895c5..5efa7e0 100644
> >> --- a/arch/arm/boot/dts/Makefile
> >> +++ b/arch/arm/boot/dts/Makefile
> >> @@ -57,6 +57,7 @@ dtb-$(CONFIG_ARCH_EXYNOS) += exynos4210-origen.dtb
> >> \
> >> 
> >>       exynos5440-sd5v1.dtb \
> >>       exynos5250-smdk5250.dtb \
> >>       exynos5250-snow.dtb \
> >> 
> >> +     exynos5420-smdk5420.dtb \
> >> 
> >>       exynos5440-ssdk5440.dtb
> >>  
> >>  dtb-$(CONFIG_ARCH_HIGHBANK) += highbank.dtb \
> >>  
> >>       ecx-2000.dtb
> >> 
> >> diff --git a/arch/arm/boot/dts/exynos5420-smdk5420.dts
> >> b/arch/arm/boot/dts/exynos5420-smdk5420.dts new file mode 100644
> >> index 0000000..d14ece5
> >> --- /dev/null
> >> +++ b/arch/arm/boot/dts/exynos5420-smdk5420.dts
> >> @@ -0,0 +1,33 @@
> >> +/*
> >> + * SAMSUNG SMDK5420 board device tree source
> >> + *
> >> + * Copyright (c) 2013 Samsung Electronics Co., Ltd.
> >> + *           http://www.samsung.com
> >> + *
> >> + * This program is free software; you can redistribute it and/or
> >> modify + * it under the terms of the GNU General Public License
> >> version 2 as + * published by the Free Software Foundation.
> >> +*/
> >> +
> >> +/dts-v1/;
> >> +#include "exynos5420.dtsi"
> >> +
> >> +/ {
> >> +     model = "Samsung SMDK5420 board based on EXYNOS5420";
> >> +     compatible = "samsung,smdk5420", "samsung,exynos5420";
> >> +
> >> +     memory {
> >> +             reg =   <0x20000000 0x80000000>;
> >> +     };
> >> +
> >> +     chosen {
> >> +             bootargs = "console=ttySAC2,115200 init=/linuxrc";
> >> +     };
> >> +
> >> +     fixed-rate-clocks {
> >> +             oscclk {
> >> +                     compatible = "samsung,exynos5420-oscclk";
> >> +                     clock-frequency = <24000000>;
> >> +             };
> >> +     };
> >> +};
> >> diff --git a/arch/arm/boot/dts/exynos5420.dtsi
> >> b/arch/arm/boot/dts/exynos5420.dtsi new file mode 100644
> >> index 0000000..e865be5
> >> --- /dev/null
> >> +++ b/arch/arm/boot/dts/exynos5420.dtsi
> >> @@ -0,0 +1,103 @@
> >> +/*
> >> + * SAMSUNG EXYNOS5420 SoC device tree source
> >> + *
> >> + * Copyright (c) 2013 Samsung Electronics Co., Ltd.
> >> + *           http://www.samsung.com
> >> + *
> >> + * SAMSUNG EXYNOS54200 SoC device nodes are listed in this file.
> >> + * EXYNOS5420 based board files can include this file and provide
> >> + * values for board specfic bindings.
> >> + *
> >> + * This program is free software; you can redistribute it and/or
> >> modify + * it under the terms of the GNU General Public License
> >> version 2 as + * published by the Free Software Foundation.
> >> + */
> >> +
> >> +#include "exynos5.dtsi"
> >> +/ {
> >> +     compatible = "samsung,exynos5420";
> >> +
> >> +     cpus {
> >> +             #address-cells = <1>;
> >> +             #size-cells = <0>;
> >> +
> >> +             cpu0: cpu at 0 {
> >> +                     device_type = "cpu";
> >> +                     compatible = "arm,cortex-a15";
> >> +                     reg = <0x0>;
> >> +                     clock-frequency = <800000000>;
> > 
> > It is the only frequency at which this SoC can run? What code does
> > actually use this property? Can't this frequency be read by calling
> > clk_get_rate() on armclk?
> 
> This is the max cpu frequency.
> This property is used in "parse_dt_topology" in
> arch/arm/kernel/topology.c" to calculate cpu capacity.

OK, fine. Thanks for the explanation.

I think we just found some kind of brokenness, because this is obviously 
incorrect (the frequency is often dependent on many configuration factors 
and should be received at runtime, for example from clock driver), but 
that's nothing related to your patches.

Best regards,
Tomasz

> 
> > Otherwise looks good:
> > 
> > Reviewed-by: Tomasz Figa <[email-masked]>
> > 
> > Best regards,
> > Tomasz
> > 
> >> +             };
> >> +
> >> +             cpu1: cpu at 1 {
> >> +                     device_type = "cpu";
> >> +                     compatible = "arm,cortex-a15";
> >> +                     reg = <0x1>;
> >> +                     clock-frequency = <800000000>;
> >> +             };
> >> +
> >> +             cpu2: cpu at 2 {
> >> +                     device_type = "cpu";
> >> +                     compatible = "arm,cortex-a15";
> >> +                     reg = <0x2>;
> >> +                     clock-frequency = <800000000>;
> >> +             };
> >> +
> >> +             cpu3: cpu at 3 {
> >> +                     device_type = "cpu";
> >> +                     compatible = "arm,cortex-a15";
> >> +                     reg = <0x3>;
> >> +                     clock-frequency = <800000000>;
> >> +             };
> >> +     };
> >> +
> >> +     clock: clock-controller at 0x10010000 {
> >> +             compatible = "samsung,exynos5420-clock";
> >> +             reg = <0x10010000 0x30000>;
> >> +             #clock-cells = <1>;
> >> +     };
> >> +
> >> +     mct at 101C0000 {
> >> +             compatible = "samsung,exynos4210-mct";
> >> +             reg = <0x101C0000 0x800>;
> >> +             interrupt-controller;
> >> +             #interrups-cells = <1>;
> >> +             interrupt-parent = <&mct_map>;
> >> +             interrupts = <0>, <1>, <2>, <3>, <4>, <5>, <6>, <7>;
> >> +             clocks = <&clock 1>, <&clock 315>;
> >> +             clock-names = "fin_pll", "mct";
> >> +
> >> +             mct_map: mct-map {
> >> +                     #interrupt-cells = <1>;
> >> +                     #address-cells = <0>;
> >> +                     #size-cells = <0>;
> >> +                     interrupt-map = <0 &combiner 23 3>,
> >> +                                     <1 &combiner 23 4>,
> >> +                                     <2 &combiner 25 2>,
> >> +                                     <3 &combiner 25 3>,
> >> +                                     <4 &gic 0 120 0>,
> >> +                                     <5 &gic 0 121 0>,
> >> +                                     <6 &gic 0 122 0>,
> >> +                                     <7 &gic 0 123 0>;
> >> +             };
> >> +     };
> >> +
> >> +     serial at 12C00000 {
> >> +             clocks = <&clock 257>, <&clock 128>;
> >> +             clock-names = "uart", "clk_uart_baud0";
> >> +     };
> >> +
> >> +     serial at 12C10000 {
> >> +             clocks = <&clock 258>, <&clock 129>;
> >> +             clock-names = "uart", "clk_uart_baud0";
> >> +     };
> >> +
> >> +     serial at 12C20000 {
> >> +             clocks = <&clock 259>, <&clock 130>;
> >> +             clock-names = "uart", "clk_uart_baud0";
> >> +     };
> >> +
> >> +     serial at 12C30000 {
> >> +             clocks = <&clock 260>, <&clock 131>;
> >> +             clock-names = "uart", "clk_uart_baud0";
> >> +     };
> >> +};
> 
> --
> with warm regards,
> Chander Kashyap
> --
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