regulator: dt-bindings: rpi-panel: Split 7" Raspberry Pi 720x1280 v2 binding

The 5" and 7" Raspberry Pi 720x1280 Display 2 MCU is a bit more
complex than the original Display 1 ATTINY88 and the binding is
also a bit more demanding. Split the binding into separate file
and fill in required gpio-controller, #gpio-cells and #pwm-cells
which must be present for the V2 MCU. Include mention of the 5"
panel in the description of Display 2, as the 5" panel uses the
same MCU.

Fixes: 6d09c6e474bd ("regulator: dt-bindings: rpi-panel: Add regulator for 7" Raspberry Pi 720x1280")
Signed-off-by: Marek Vasut <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Message-ID: <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator-v2.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/raspberrypi,7inch-touchscreen-panel-regulator-v2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RaspberryPi 5" and 7" display V2 MCU-based regulator/backlight controller
+
+maintainers:
+  - Marek Vasut <[e-mail]>
+
+description: |
+  The RaspberryPi 5" and 7" display 2 has an MCU-based regulator, PWM
+  backlight and GPIO controller on the PCB, which is used to turn the
+  display unit on/off and control the backlight.
+
+allOf:
+  - $ref: regulator.yaml#
+
+properties:
+  compatible:
+    const: raspberrypi,touchscreen-panel-regulator-v2
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+  "#gpio-cells":
+    const: 2
+    description:
+      The first cell is the pin number, and the second cell is used to
+      specify the gpio polarity (GPIO_ACTIVE_HIGH or GPIO_ACTIVE_LOW).
+
+  "#pwm-cells":
+    const: 3
+    description: See ../../pwm/pwm.yaml for description of the cell formats.
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+  - "#pwm-cells"
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      regulator@45 {
+        compatible = "raspberrypi,touchscreen-panel-regulator-v2";
+        reg = <0x45>;
+        gpio-controller;
+        #gpio-cells = <2>;
+        #pwm-cells = <3>;
+      };
+    };
+
+...

Documentation/devicetree/bindings/regulator/raspberrypi,7inch-touchscreen-panel-regulator.yaml

···
 description: |
   The RaspberryPi 7" display has an ATTINY88-based regulator/backlight
   controller on the PCB, which is used to turn the display unit on/off
-  and control the backlight. The V2 supports 5" and 7" panels and also
-  offers PWM backlight control.
+  and control the backlight.
 
 allOf:
   - $ref: regulator.yaml#
 
 properties:
   compatible:
-    enum:
-      - raspberrypi,7inch-touchscreen-panel-regulator
-      - raspberrypi,touchscreen-panel-regulator-v2
+    const: raspberrypi,7inch-touchscreen-panel-regulator
 
   reg:
     maxItems: 1