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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
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Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+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>;
+};