dt-bindings: nvmem: Add bindings for ZynqMP nvmem driver

Add documentation to describe Xilinx ZynqMP nvmem driver
bindings.

Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.txt b/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.txt
new file mode 100644 (file)
index 0000000..4881561
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/xlnx,zynqmp-nvmem.txt
@@ -0,0 +1,46 @@
+--------------------------------------------------------------------------
+=  Zynq UltraScale+ MPSoC nvmem firmware driver binding =
+--------------------------------------------------------------------------
+The nvmem_firmware node provides access to the hardware related data
+like soc revision, IDCODE... etc, By using the firmware interface.
+
+Required properties:
+- compatible: should be "xlnx,zynqmp-nvmem-fw"
+
+= Data cells =
+Are child nodes of silicon id, bindings of which as described in
+bindings/nvmem/nvmem.txt
+
+-------
+ Example
+-------
+firmware {
+       zynqmp_firmware: zynqmp-firmware {
+               compatible = "xlnx,zynqmp-firmware";
+               method = "smc";
+
+               nvmem_firmware {
+                       compatible = "xlnx,zynqmp-nvmem-fw";
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+
+                       /* Data cells */
+                       soc_revision: soc_revision {
+                               reg = <0x0 0x4>;
+                       };
+               };
+       };
+};
+
+= Data consumers =
+Are device nodes which consume nvmem data cells.
+
+For example:
+       pcap {
+               ...
+
+               nvmem-cells = <&soc_revision>;
+               nvmem-cell-names = "soc_revision";
+
+               ...
+       };