[PATCH 2/8] dt-bindings: display: panel: novatek,nt36672e: Add bias enable GPIO

[Vladimir Zapolskiy <vz@kernel.org>]

The pair of positive and negative bias supplies of an NT36672E panel,
AVDD and AVEE, also known as VSP and VSN, are either provided by the host,
or generated on the panel module itself. In the latter case the module
exposes only a bias enable signal with no need to describe the supplies.

Make the AVDD and AVEE supplies optional, but require them to be
described together as the indivisible pair, and add an optional enable
GPIO for the bias enable signal of the panel module, which excludes
the bias supplies, if present in the actual device tree node.

Signed-off-by: Vladimir Zapolskiy <vz@kernel.org>
---
 .../display/panel/novatek,nt36672e.yaml       | 32 +++++++++++++++----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/panel/novatek,nt36672e.yaml b/Documentation/devicetree/bindings/display/panel/novatek,nt36672e.yaml
index 45743376995b..daf2f96b8ed4 100644
--- a/Documentation/devicetree/bindings/display/panel/novatek,nt36672e.yaml
+++ b/Documentation/devicetree/bindings/display/panel/novatek,nt36672e.yaml
@@ -11,6 +11,13 @@ maintainers:
 
 allOf:
   - $ref: panel-common.yaml#
+  - if:
+      required:
+        - enable-gpios
+    then:
+      properties:
+        avdd-supply: false
+        avee-supply: false
 
 properties:
   compatible:
@@ -21,8 +28,20 @@ properties:
     description: DSI virtual channel
 
   vddi-supply: true
-  avdd-supply: true
-  avee-supply: true
+
+  avdd-supply:
+    description: Positive bias supply of the panel
+
+  avee-supply:
+    description: Negative bias supply of the panel
+
+  enable-gpios:
+    maxItems: 1
+    description:
+      GPIO connected to the bias enable signal of the panel module, which
+      switches on the positive and negative bias supplies generated on the
+      module. The signal is active high.
+
   port: true
   reset-gpios:
     maxItems: 1
@@ -38,11 +57,13 @@ required:
   - compatible
   - reg
   - vddi-supply
-  - avdd-supply
-  - avee-supply
   - reset-gpios
   - port
 
+dependentRequired:
+  avdd-supply: [avee-supply]
+  avee-supply: [avdd-supply]
+
 additionalProperties: false
 
 examples:
@@ -55,11 +76,10 @@ examples:
             compatible = "novatek,nt36672e";
             reg = <0>;
 
+            enable-gpios = <&pmic_gpios 8 GPIO_ACTIVE_HIGH>;
             reset-gpios = <&tlmm 44 GPIO_ACTIVE_HIGH>;
 
             vddi-supply = <&vreg_l8c_1p8>;
-            avdd-supply = <&disp_avdd>;
-            avee-supply = <&disp_avee>;
 
             backlight = <&pwm_backlight>;
 
-- 
2.51.0