[PATCH v4 1/2] dt-bindings: arm: atmel: describe SECUMOD usage as a GPIO controller

From: Andrei.Stefanescu
Date: Wed Dec 12 2018 - 06:57:17 EST

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@xxxxxxxxxxxxx>
Documentation/devicetree/bindings/arm/atmel-sysregs.txt | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/atmel-sysregs.txt b/Documentation/devicetree/bindings/arm/atmel-sysregs.txt
index 4b96608..c89db84 100644
--- 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>;