spi: sh-spi: Improve bindings

  - Add future-proof "renesas,hspi-<soctype>" compatible values,
  - Add missing "interrupt-parent", "#address-cells", and "#size-cells"
    properties,
  - Add reference to pinctrl documentation,
  - Add example bindings.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 25 insertions, 3 deletions

diff --git a/Documentation/devicetree/bindings/spi/sh-hspi.txt b/Documentation/devicetree/bindings/spi/sh-hspi.txt
index 30b57b1c8a13..319bad4af875 100644
--- a/Documentation/devicetree/bindings/spi/sh-hspi.txt
+++ b/Documentation/devicetree/bindings/spi/sh-hspi.txt
@@ -1,7 +1,29 @@
 Renesas HSPI.
 
 Required properties:
-- compatible :  "renesas,hspi"
-- reg : Offset and length of the register set for the device
-- interrupts : interrupt line used by HSPI
+- compatible       : "renesas,hspi-<soctype>", "renesas,hspi" as fallback.
+                     Examples with soctypes are:
+                       - "renesas,hspi-r8a7778" (R-Car M1)
+                       - "renesas,hspi-r8a7779" (R-Car H1)
+- reg              : Offset and length of the register set for the device
+- interrupt-parent : The phandle for the interrupt controller that
+                     services interrupts for this device
+- interrupts       : Interrupt specifier
+- #address-cells   : Must be <1>
+- #size-cells      : Must be <0>
+
+Pinctrl properties might be needed, too.  See
+Documentation/devicetree/bindings/pinctrl/renesas,*.
+
+Example:
+
+        hspi0: spi@fffc7000 {
+                compatible = "renesas,hspi-r8a7778", "renesas,hspi";
+                reg = <0xfffc7000 0x18>;
+                interrupt-parent = <&gic>;
+                interrupts = <0 63 IRQ_TYPE_LEVEL_HIGH>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+                status = "disabled";
+        };