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