Document the ast2400, ast2500 PCI-to-AHB bridge control driver bindings.
Signed-off-by: Patrick Venture <venture@xxxxxxxxxx>
---
Changes for v8:
- None
Changes for v7:
- Moved node under the syscon node it requires
Changes for v6:
- None
Changes for v5:
- None
Changes for v4:
- None
Changes for v3:
- None
Changes for v2:
- Added comment about syscon required parameter.
---
.../bindings/misc/aspeed-p2a-ctrl.txt | 48 +++++++++++++++++++
1 file changed, 48 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt
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 0000000000000..088cc4e3dc54b
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/aspeed-p2a-ctrl.txt
@@ -0,0 +1,48 @@
+======================================================================
+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"
+
+ - syscon: handle to syscon device node controlling PCI.
+
+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>;
+ };
+};
--
2.21.0.392.gf8f6787159e-goog
