i2c: rcar: add Device Tree support

This patch adds Device Tree support to the i2c-rcar driver and respective
documentation.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt
new file mode 100644
index 000000000000..897cfcd5ce92
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt
@@ -0,0 +1,23 @@
+I2C for R-Car platforms
+
+Required properties:
+- compatible: Must be one of
+        "renesas,i2c-rcar"
+        "renesas,i2c-r8a7778"
+        "renesas,i2c-r8a7779"
+        "renesas,i2c-r8a7790"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- interrupts: interrupt specifier.
+
+Optional properties:
+- clock-frequency: desired I2C bus clock frequency in Hz. The absence of this
+  propoerty indicates the default frequency 100 kHz.
+
+Examples :
+
+i2c0: i2c@e6500000 {
+        compatible = "renesas,i2c-rcar-h2";
+        reg = <0 0xe6500000 0 0x428>;
+        interrupts = <0 174 0x4>;
+};