syscon: dt-bindings: Add binding document for iProc MHB block

Add binding document for Broadcom iProc's Multi-Host Bridge (MHB)
block

Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/Documentation/devicetree/bindings/mfd/brcm,iproc-mhb.txt b/Documentation/devicetree/bindings/mfd/brcm,iproc-mhb.txt
new file mode 100644 (file)
index 0000000..4421e97
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/brcm,iproc-mhb.txt
@@ -0,0 +1,18 @@
+Broadcom iProc Multi Host Bridge (MHB)
+
+Certain Broadcom iProc SoCs have a multi host bridge (MHB) block that controls
+the connection and configuration of 1) internal PCIe serdes; 2) PCIe endpoint
+interface; 3) access to the Nitro (network processing) engine
+
+This node allows access to these MHB registers via syscon.
+
+Required properties:
+- compatible: should contain:
+               "brcm,sr-mhb", "syscon" for Stingray
+- reg: base address and range of the MHB registers
+
+Example:
+       mhb: syscon@60401000 {
+               compatible = "brcm,sr-mhb", "syscon";
+               reg = <0 0x60401000 0 0x38c>;
+       };