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-rw-r--r-- | Documentation/devicetree/bindings/sram/sunxi-sram.txt | 99 |
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diff --git a/Documentation/devicetree/bindings/sram/sunxi-sram.txt b/Documentation/devicetree/bindings/sram/sunxi-sram.txt new file mode 100644 index 000000000..c51ade865 --- /dev/null +++ b/Documentation/devicetree/bindings/sram/sunxi-sram.txt @@ -0,0 +1,99 @@ +Allwinnner SoC SRAM controllers +----------------------------------------------------- + +The SRAM controller found on most Allwinner devices is represented by +a regular node for the SRAM controller itself, with sub-nodes +reprensenting the SRAM handled by the SRAM controller. + +Controller Node +--------------- + +Required properties: +- compatible : should be: + - "allwinner,sun4i-a10-sram-controller" (deprecated) + - "allwinner,sun4i-a10-system-control" + - "allwinner,sun5i-a13-system-control" + - "allwinner,sun7i-a20-system-control", "allwinner,sun4i-a10-system-control" + - "allwinner,sun8i-a23-system-control" + - "allwinner,sun8i-h3-system-control" + - "allwinner,sun50i-a64-sram-controller" (deprecated) + - "allwinner,sun50i-a64-system-control" +- reg : sram controller register offset + length + +SRAM nodes +---------- + +Each SRAM is described using the mmio-sram bindings documented in +Documentation/devicetree/bindings/sram/sram.txt + +Each SRAM will have SRAM sections that are going to be handled by the +SRAM controller as subnodes. These sections are represented following +once again the representation described in the mmio-sram binding. + +The valid sections compatible for A10 are: + - allwinner,sun4i-a10-sram-a3-a4 + - allwinner,sun4i-a10-sram-c1 + - allwinner,sun4i-a10-sram-d + +The valid sections compatible for A13 are: + - allwinner,sun5i-a13-sram-a3-a4, allwinner,sun4i-a10-sram-a3-a4 + - allwinner,sun5i-a13-sram-c1, allwinner,sun4i-a10-sram-c1 + - allwinner,sun5i-a13-sram-d, allwinner,sun4i-a10-sram-d + +The valid sections compatible for A20 are: + - allwinner,sun7i-a20-sram-a3-a4, allwinner,sun4i-a10-sram-a3-a4 + - allwinner,sun7i-a20-sram-c1, allwinner,sun4i-a10-sram-c1 + - allwinner,sun7i-a20-sram-d, allwinner,sun4i-a10-sram-d + +The valid sections compatible for A23/A33 are: + - allwinner,sun8i-a23-sram-c1, allwinner,sun4i-a10-sram-c1 + +The valid sections compatible for H3 are: + - allwinner,sun8i-h3-sram-c1, allwinner,sun4i-a10-sram-c1 + +The valid sections compatible for A64 are: + - allwinner,sun50i-a64-sram-c + +Devices using SRAM sections +--------------------------- + +Some devices need to request to the SRAM controller to map an SRAM for +their exclusive use. + +The relationship between such a device and an SRAM section is +expressed through the allwinner,sram property, that will take a +phandle and an argument. + +This valid values for this argument are: + - 0: CPU + - 1: Device + +Example +------- +system-control@1c00000 { + compatible = "allwinner,sun4i-a10-system-control"; + reg = <0x01c00000 0x30>; + #address-cells = <1>; + #size-cells = <1>; + ranges; + + sram_a: sram@00000000 { + compatible = "mmio-sram"; + reg = <0x00000000 0xc000>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x00000000 0xc000>; + + emac_sram: sram-section@8000 { + compatible = "allwinner,sun4i-a10-sram-a3-a4"; + reg = <0x8000 0x4000>; + }; + }; +}; + +emac: ethernet@1c0b000 { + compatible = "allwinner,sun4i-a10-emac"; + ... + + allwinner,sram = <&emac_sram 1>; +}; |