gpio-rcar: Add DT support

Add DT bindings for the gpio-rcar driver and read the device
configuration from the DT node at probe time if available.

Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 52 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
new file mode 100644
index 000000000000..46d76a004246
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
@@ -0,0 +1,52 @@
+* Renesas R-Car GPIO Controller
+
+Required Properties:
+
+  - compatible: should be one of the following.
+    - "renesas,gpio-r8a7778": for R8A7778 (R-Mobile M1) compatible GPIO controller.
+    - "renesas,gpio-r8a7779": for R8A7779 (R-Car H1) compatible GPIO controller.
+    - "renesas,gpio-r8a7790": for R8A7790 (R-Car H2) compatible GPIO controller.
+    - "renesas,gpio-rcar": for generic R-Car GPIO controller.
+
+  - reg: Base address and length of each memory resource used by the GPIO
+    controller hardware module.
+
+  - interrupt-parent: phandle of the parent interrupt controller.
+  - interrupts: Interrupt specifier for the controllers interrupt.
+
+  - gpio-controller: Marks the device node as a gpio controller.
+  - #gpio-cells: Should be 2. The first cell is the GPIO number and the second
+    cell is used to specify optional parameters as bit flags. Only the GPIO
+    active low flag (bit 0) is currently supported.
+  - gpio-ranges: Range of pins managed by the GPIO controller as a 4-cells
+    tuple using the following syntax.
+
+    <[phandle of the pin controller node]
+     0
+     [index of the first pin]
+     [number of pins]>
+
+Please refer to gpio.txt in this directory for details of the common GPIO
+bindings used by client devices.
+
+Example: R8A7779 (R-Car H1) GPIO controller nodes
+
+        gpio0: gpio@ffc40000 {
+                compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+                reg = <0xffc40000 0x2c>;
+                interrupt-parent = <&gic>;
+                interrupts = <0 141 0x4>;
+                #gpio-cells = <2>;
+                gpio-controller;
+                gpio-ranges = <&pfc 0 0 32>;
+        };
+        ...
+        gpio6: gpio@ffc46000 {
+                compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+                reg = <0xffc46000 0x2c>;
+                interrupt-parent = <&gic>;
+                interrupts = <0 147 0x4>;
+                #gpio-cells = <2>;
+                gpio-controller;
+                gpio-ranges = <&pfc 0 192 9>;
+        };