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authorPatrick Venture <venture@google.com>2019-04-08 17:42:16 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-25 20:33:33 +0300
commit28703c6ef6228635f7c8b248c1d846511a2b60a3 (patch)
treee8f0d8838033a2c2bcd204c974fc8e6c081c5a67 /Documentation/devicetree/bindings/misc
parent3a26172437bb5ecdf6921e3ae24730ef37d3c860 (diff)
downloadlinux-28703c6ef6228635f7c8b248c1d846511a2b60a3.tar.xz
dt-bindings: misc: aspeed-p2a-ctrl: add support
Document the ast2400, ast2500 PCI-to-AHB bridge control driver bindings. Signed-off-by: Patrick Venture <venture@google.com> Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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+======================================================================
+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:
+===================
+
+- 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,g4-scu", "syscon", "simple-mfd"
+ "aspeed,ast2500-scu", "syscon", "simple-mfd"
+ "aspeed,g5-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>;
+ };
+};