ARM: socfpga: add bindings document for fpga bridge drivers

Add bindings documentation for Altera SOCFPGA bridges:
 * fpga2sdram
 * fpga2hps
 * hps2fpga
 * lwhps2fpga

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Matthew Gerlach <mgerlach@altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt b/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt
new file mode 100644
index 000000000000..817a8d4bf903
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/altera-fpga2sdram-bridge.txt
@@ -0,0 +1,16 @@
+Altera FPGA To SDRAM Bridge Driver
+
+Required properties:
+- compatible		: Should contain "altr,socfpga-fpga2sdram-bridge"
+
+Optional properties:
+- bridge-enable		: 0 if driver should disable bridge at startup
+			  1 if driver should enable bridge at startup
+			  Default is to leave bridge in current state.
+
+Example:
+	fpga_bridge3: fpga-bridge@ffc25080 {
+		compatible = "altr,socfpga-fpga2sdram-bridge";
+		reg = <0xffc25080 0x4>;
+		bridge-enable = <0>;
+	};