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Diffstat (limited to 'Documentation/devicetree/bindings/sram/sram.yaml')
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diff --git a/Documentation/devicetree/bindings/sram/sram.yaml b/Documentation/devicetree/bindings/sram/sram.yaml new file mode 100644 index 000000000000..ee2287a1b14d --- /dev/null +++ b/Documentation/devicetree/bindings/sram/sram.yaml @@ -0,0 +1,257 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/sram/sram.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic on-chip SRAM + +maintainers: + - Rob Herring <robh@kernel.org> + +description: |+ + Simple IO memory regions to be managed by the genalloc API. + + Each child of the sram node specifies a region of reserved memory. Each + child node should use a 'reg' property to specify a specific range of + reserved memory. + + Following the generic-names recommended practice, node names should + reflect the purpose of the node. Unit address (@<address>) should be + appended to the name. + +properties: + $nodename: + pattern: "^sram(@.*)?" + + compatible: + contains: + enum: + - mmio-sram + - atmel,sama5d2-securam + + reg: + maxItems: 1 + + clocks: + description: + A list of phandle and clock specifier pair that controls the single + SRAM clock. + + "#address-cells": + const: 1 + + "#size-cells": + const: 1 + + ranges: + description: + Should translate from local addresses within the sram to bus addresses. + + no-memory-wc: + description: + The flag indicating, that SRAM memory region has not to be remapped + as write combining. WC is used by default. + type: boolean + +patternProperties: + "^([a-z]*-)?sram@[a-f0-9]+$": + type: object + description: + Each child of the sram node specifies a region of reserved memory. + properties: + compatible: + description: + Should contain a vendor specific string in the form + <vendor>,[<device>-]<usage> + enum: + - allwinner,sun9i-a80-smp-sram + - amlogic,meson8-smp-sram + - amlogic,meson8b-smp-sram + - renesas,smp-sram + - rockchip,rk3066-smp-sram + - samsung,exynos4210-sysram + - samsung,exynos4210-sysram-ns + - socionext,milbeaut-smp-sram + + reg: + description: + IO mem address range, relative to the SRAM range. + maxItems: 1 + + pool: + description: + Indicates that the particular reserved SRAM area is addressable + and in use by another device or devices. + type: boolean + + export: + description: + Indicates that the reserved SRAM area may be accessed outside + of the kernel, e.g. by bootloader or userspace. + type: boolean + + protect-exec: + description: | + Same as 'pool' above but with the additional constraint that code + will be run from the region and that the memory is maintained as + read-only, executable during code execution. NOTE: This region must + be page aligned on start and end in order to properly allow + manipulation of the page attributes. + type: boolean + + label: + description: + The name for the reserved partition, if omitted, the label is taken + from the node name excluding the unit address. + + required: + - reg + + additionalProperties: false + +required: + - compatible + - reg + - "#address-cells" + - "#size-cells" + - ranges + +additionalProperties: false + +examples: + - | + sram@5c000000 { + compatible = "mmio-sram"; + reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */ + + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x5c000000 0x40000>; + + smp-sram@100 { + reg = <0x100 0x50>; + }; + + device-sram@1000 { + reg = <0x1000 0x1000>; + pool; + }; + + exported-sram@20000 { + reg = <0x20000 0x20000>; + export; + }; + }; + + - | + // Samsung SMP-capable Exynos SoCs use part of the SYSRAM for the bringup + // of the secondary cores. Once the core gets powered up it executes the + // code that is residing at some specific location of the SYSRAM. + // + // Therefore reserved section sub-nodes have to be added to the mmio-sram + // declaration. These nodes are of two types depending upon secure or + // non-secure execution environment. + sram@2020000 { + compatible = "mmio-sram"; + reg = <0x02020000 0x54000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x02020000 0x54000>; + + smp-sram@0 { + compatible = "samsung,exynos4210-sysram"; + reg = <0x0 0x1000>; + }; + + smp-sram@53000 { + compatible = "samsung,exynos4210-sysram-ns"; + reg = <0x53000 0x1000>; + }; + }; + + - | + // Amlogic's SMP-capable SoCs use part of the sram for the bringup of the cores. + // Once the core gets powered up it executes the code that is residing at a + // specific location. + // + // Therefore a reserved section sub-node has to be added to the mmio-sram + // declaration. + sram@d9000000 { + compatible = "mmio-sram"; + reg = <0xd9000000 0x20000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0xd9000000 0x20000>; + + smp-sram@1ff80 { + compatible = "amlogic,meson8b-smp-sram"; + reg = <0x1ff80 0x8>; + }; + }; + + - | + sram@e63c0000 { + compatible = "mmio-sram"; + reg = <0xe63c0000 0x1000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0xe63c0000 0x1000>; + + smp-sram@0 { + compatible = "renesas,smp-sram"; + reg = <0 0x10>; + }; + }; + + - | + sram@10080000 { + compatible = "mmio-sram"; + reg = <0x10080000 0x10000>; + #address-cells = <1>; + #size-cells = <1>; + ranges; + + smp-sram@10080000 { + compatible = "rockchip,rk3066-smp-sram"; + reg = <0x10080000 0x50>; + }; + }; + + - | + // Allwinner's A80 SoC uses part of the secure sram for hotplugging of the + // primary core (cpu0). Once the core gets powered up it checks if a magic + // value is set at a specific location. If it is then the BROM will jump + // to the software entry address, instead of executing a standard boot. + // + // Also there are no "secure-only" properties. The implementation should + // check if this SRAM is usable first. + sram@20000 { + // 256 KiB secure SRAM at 0x20000 + compatible = "mmio-sram"; + reg = <0x00020000 0x40000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x00020000 0x40000>; + + smp-sram@1000 { + // This is checked by BROM to determine if + // cpu0 should jump to SMP entry vector + compatible = "allwinner,sun9i-a80-smp-sram"; + reg = <0x1000 0x8>; + }; + }; + + - | + sram@0 { + compatible = "mmio-sram"; + reg = <0x0 0x10000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x0 0x10000>; + + smp-sram@f100 { + compatible = "socionext,milbeaut-smp-sram"; + reg = <0xf100 0x20>; + }; + }; |