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Diffstat (limited to 'Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt')
-rw-r--r-- | Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt | 46 |
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diff --git a/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt b/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt new file mode 100644 index 000000000..f2e2e28b3 --- /dev/null +++ b/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt @@ -0,0 +1,46 @@ +====================================================================== +Device tree bindings for Aspeed AST2400/AST2500 PCI-to-AHB Bridge Control Driver +====================================================================== + +The bridge is available on platforms with the VGA enabled on the Aspeed device. +In this case, the host has access to a 64KiB window into all of the BMC's +memory. The BMC can disable this bridge. If the bridge is enabled, the host +has read access to all the regions of memory, however the host only has read +and write access depending on a register controlled by the BMC. + +Required properties: +=================== + + - compatible: must be one of: + - "aspeed,ast2400-p2a-ctrl" + - "aspeed,ast2500-p2a-ctrl" + +Optional properties: +=================== + +- reg: A hint for the memory regions associated with the P2A controller +- memory-region: A phandle to a reserved_memory region to be used for the PCI + to AHB mapping + +The p2a-control node should be the child of a syscon node with the required +property: + +- compatible : Should be one of the following: + "aspeed,ast2400-scu", "syscon", "simple-mfd" + "aspeed,ast2500-scu", "syscon", "simple-mfd" + +Example +=================== + +g4 Example +---------- + +syscon: scu@1e6e2000 { + compatible = "aspeed,ast2400-scu", "syscon", "simple-mfd"; + reg = <0x1e6e2000 0x1a8>; + + p2a: p2a-control { + compatible = "aspeed,ast2400-p2a-ctrl"; + memory-region = <&reserved_memory>; + }; +}; |