dt-bindings: display: panel: Add bindings for Novatek nt36672a

Novatek nt36672a is a display driver IC that can drive DSI panel. It
is also present in the Tianma video mode panel, which is a FHD+ panel
with a resolution of 1080x2246 and 6.18 inches size. It is found in
some of the Poco F1 phones.

This patch adds the display driver for the IC, with support added for
this tianma fhd video mode panel.
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200902064407.30712-2-sumit.semwal@linaro.org

Documentation/devicetree/bindings/display/panel/novatek,nt36672a.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/novatek,nt36672a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Novatek NT36672A based DSI display Panels
+
+maintainers:
+  - Sumit Semwal <sumit.semwal@linaro.org>
+
+description: |
+  The nt36672a IC from Novatek is a generic DSI Panel IC used to drive dsi
+  panels.
+  Right now, support is added only for a Tianma FHD+ LCD display panel with a
+  resolution of 1080x2246. It is a video mode DSI panel.
+
+allOf:
+  - $ref: panel-common.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+         - tianma,fhd-video
+      - const: novatek,nt36672a
+    description: This indicates the panel manufacturer of the panel that is
+      in turn using the NT36672A panel driver. This compatible string
+      determines how the NT36672A panel driver is configured for the indicated
+      panel. The novatek,nt36672a compatible shall always be provided as a fallback.
+
+  reset-gpios:
+    description: phandle of gpio for reset line - This should be 8mA, gpio
+      can be configured using mux, pinctrl, pinctrl-names (active high)
+
+  vddio-supply:
+    description: phandle of the regulator that provides the supply voltage
+      Power IC supply
+
+  vddpos-supply:
+    description: phandle of the positive boost supply regulator
+
+  vddneg-supply:
+    description: phandle of the negative boost supply regulator
+
+  reg: true
+  port: true
+
+required:
+  - compatible
+  - reg
+  - vddi0-supply
+  - vddpos-supply
+  - vddneg-supply
+  - reset-gpios
+  - port
+
+unevaluatedProperties: false
+
+examples:
+  - |+
+    #include <dt-bindings/gpio/gpio.h>
+
+    dsi0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        panel@0 {
+            compatible = "tianma,fhd-video", "novatek,nt36672a";
+            reg = <0>;
+            vddi0-supply = <&vreg_l14a_1p88>;
+            vddpos-supply = <&lab>;
+            vddneg-supply = <&ibb>;
+
+            reset-gpios = <&tlmm 6 GPIO_ACTIVE_HIGH>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+            port {
+                tianma_nt36672a_in_0: endpoint {
+                    remote-endpoint = <&dsi0_out>;
+                };
+            };
+        };
+    };
+
+...