[PATCH 3/4] ARM: shmobile: Document DT bindings for Product Register

[Simon Horman]

From: Geert Uytterhoeven <geert+renesas at glider.be>

Add device tree binding documentation for the Product Register (PRR),
which provides product and revision information on most Renesas ARM
SoCs.

Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
Acked-by: Rob Herring <robh at kernel.org>
Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
---
 Documentation/devicetree/bindings/arm/shmobile.txt | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/shmobile.txt b/Documentation/devicetree/bindings/arm/shmobile.txt
index 2f0b7169f132..23c77315fdac 100644
--- a/Documentation/devicetree/bindings/arm/shmobile.txt
+++ b/Documentation/devicetree/bindings/arm/shmobile.txt
@@ -75,3 +75,21 @@ Boards:
     compatible = "renesas,silk", "renesas,r8a7794"
   - Wheat
     compatible = "renesas,wheat", "renesas,r8a7792"
+
+
+Most Renesas ARM SoCs have a Product Register that allows to retrieve SoC
+product and revision information.  If present, a device node for this register
+should be added.
+
+Required properties:
+  - compatible: Must be "renesas,prr".
+  - reg: Base address and length of the register block.
+
+
+Examples
+--------
+
+	prr: chipid at ff000044 {
+		compatible = "renesas,prr";
+		reg = <0 0xff000044 0 4>;
+	};
-- 
2.7.0.rc3.207.g0ac5344