dt-bindings: arm: atmel: describe SECUMOD usage as a GPIO controller

This patch describes the Security Module's usage as a GPIO
controller for its PIOBU pins. These pins have the special
property of maintaining their voltage during suspend-to-mem.

Signed-off-by: Andrei Stefanescu <andrei.stefanescu@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/Documentation/devicetree/bindings/arm/atmel-sysregs.txt b/Documentation/devicetree/bindings/arm/atmel-sysregs.txt
index 4b96608ad69252777164a02cfe117311ae288b78..14f319f694b79a34c275020152b488b2c4550f9c 100644 (file)
--- a/Documentation/devicetree/bindings/arm/atmel-sysregs.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-sysregs.txt
@@ -158,14 +158,24 @@ Security Module (SECUMOD)
 
 The Security Module macrocell provides all necessary secure functions to avoid
 voltage, temperature, frequency and mechanical attacks on the chip. It also
-embeds secure memories that can be scrambled
+embeds secure memories that can be scrambled.
+
+The Security Module also offers the PIOBU pins which can be used as GPIO pins.
+Note that they maintain their voltage during Backup/Self-refresh.
 
 required properties:
 - compatible: Should be "atmel,<chip>-secumod", "syscon".
   <chip> can be "sama5d2".
 - reg: Should contain registers location and length
+- gpio-controller:     Marks the port as GPIO controller.
+- #gpio-cells:         There are 2. The pin number is the
+                       first, the second represents additional
+                       parameters such as GPIO_ACTIVE_HIGH/LOW.
+
 
        secumod@fc040000 {
                compatible = "atmel,sama5d2-secumod", "syscon";
                reg = <0xfc040000 0x100>;
+               gpio-controller;
+               #gpio-cells = <2>;
        };