[RFC PATCH 1/3] dt-bindings: mfd: rk808: add board level power hold GPIOs

[Yaozhong Li <yaozhonguwl@gmail.com>]

Some boards route "power hold" lines from the SoC into the board's power
circuitry. Those lines have to be held asserted while the system is
running and released before the PMIC shutdown request is written; with any
of them left asserted the rails drop and then come back up.

Add power-hold-gpios to describe those lines and power-hold-delay-ms for
the settle time.

Signed-off-by: Yaozhong Li <yaozhonguwl@gmail.com>
---
 .../bindings/mfd/rockchip,rk808.yaml          | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml b/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
index 50dfffa..00cbb27 100644
--- a/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
+++ b/Documentation/devicetree/bindings/mfd/rockchip,rk808.yaml
@@ -43,6 +43,23 @@ properties:
 
   system-power-controller: true
 
+  power-hold-gpios:
+    minItems: 1
+    maxItems: 2
+    description:
+      Board level power hold lines driven by the SoC. They have to be held
+      asserted while the system is running and released before the PMIC
+      shutdown request is written; with any of them left asserted the rails
+      drop and then come back up. A line left asserted by another consumer
+      therefore defeats the sequence, so every line involved must be listed
+      here.
+
+  power-hold-delay-ms:
+    default: 0
+    description:
+      Time to wait after releasing power-hold-gpios before the shutdown
+      request is written, to let the lines settle.
+
   wakeup-source:
     type: boolean
     description:
@@ -113,6 +130,9 @@ properties:
         unevaluatedProperties: false
     unevaluatedProperties: false
 
+dependencies:
+  power-hold-delay-ms: [ power-hold-gpios ]
+
 required:
   - compatible
   - reg
-- 
2.55.0.windows.3