[PATCH 2/4] ARM: rockchip: add sram dt nodes and documentation
From: Rob Herring <hidden>
Date: 2013-06-17 23:41:27
On 06/17/2013 05:44 PM, Heiko St?bner wrote:
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The Rockchip SoCs need a special part of their sram for bringup of additional cores. Therefore the mapped area should be split into a special area for the smp code and a generic area that gets handled by mmio-sram. Signed-off-by: Heiko Stuebner <heiko@sntech.de> --- .../devicetree/bindings/arm/rockchip/smp-sram.txt | 29 ++++++++++++++++++++ arch/arm/boot/dts/rk3066a.dtsi | 14 ++++++++++ 2 files changed, 43 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/rockchip/smp-sram.txtdiff --git a/Documentation/devicetree/bindings/arm/rockchip/smp-sram.txt b/Documentation/devicetree/bindings/arm/rockchip/smp-sram.txt new file mode 100644 index 0000000..9c81fac --- /dev/null +++ b/Documentation/devicetree/bindings/arm/rockchip/smp-sram.txt@@ -0,0 +1,29 @@ +Rockchip SRAM for smp bringup: +------------------------------ + +Rockchip smp-capable SoCs use the first part of the sram for the bringup +of the cores. Once the core gets powered up it executes the code that is +residing at the very beginning of the sram. + +While the suspend also needs to have code in the sram that can be realized +with the generic mmio-sram driver and only the smp specific part needs to +be mapped specially in the smp code. + +Therefore split the sram mapping in a smp-specific part that gets used +by the smp code exclusively and a bigger generic part for mmio-sram + +Required node properties: +- compatible value : = "rockchip,rk3066-smp-sram"; +- reg : physical base address and the size of the registers window + +Example: + + sram at 10080000 { + compatible = "rockchip,rk3066-smp-sram"; + reg = <0x10080000 0x100>; + }; + + sram: sram at 10080100 { + compatible = "mmio-sram"; + reg = <0x10080100 0x9900>;
I think a better way would be to specify some portion of the sram as reserved rather than defining the s/w use of the sram in DT. Something like this: mmio-sram-reserved = <base size base size>; where base values are relative to reg property base. Rob
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+ };diff --git a/arch/arm/boot/dts/rk3066a.dtsi b/arch/arm/boot/dts/rk3066a.dtsi index 26c4311..44eabd2 100644 --- a/arch/arm/boot/dts/rk3066a.dtsi +++ b/arch/arm/boot/dts/rk3066a.dtsi@@ -53,6 +53,20 @@ reg = <0x1013c000 0x100>; }; + /* + * the first part of the sram is needed for the smp + * trampoline code during cpu bringup + */ + sram at 10080000 { + compatible = "rockchip,rk3066-smp-sram"; + reg = <0x10080000 0x100>; + }; + + sram: sram at 10080100 { + compatible = "mmio-sram"; + reg = <0x10080100 0x9900>; + }; + gic: interrupt-controller at 1013d000 { compatible = "arm,cortex-a9-gic"; interrupt-controller;