[PATCH v2 20/21] dt-bindings: gpio: describe Waveshare GPIO controller

[Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>]

The Waveshare DSI TOUCH family of panels has separate on-board GPIO
controller, which controls power supplies to the panel and the touch
screen and provides reset pins for both the panel and the touchscreen.
Also it provides a simple PWM controller for panel backlight.

Add bindings for these GPIO controllers. As overall integration might be
not very obvious (and it differs significantly from the bindings used by
the original drivers), provide complete example with the on-board
regulators and the DSI panel.

Tested-by: Riccardo Mereu <r.mereu@arduino.cc>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 .../bindings/gpio/waveshare,dsi-touch-gpio.yaml    | 100 +++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml b/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml
new file mode 100644
index 000000000000..410348fcda25
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/waveshare,dsi-touch-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Waveshare GPIO controller on DSI TOUCH panels
+
+maintainers:
+  - Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
+
+description:
+  Waveshare DSI TOUCH panel kits contain separate GPIO controller for toggling
+  power supplies and panel / touchscreen resets.
+
+properties:
+  compatible:
+    const: waveshare,dsi-touch-gpio
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        wsgpio: gpio@45 {
+            compatible = "waveshare,dsi-touch-gpio";
+            reg = <0x45>;
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };
+
+    panel_avdd: regulator-panel-avdd {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-avdd";
+        gpios = <&wsgpio 0 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+    };
+
+    panel_iovcc: regulator-panel-iovcc {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-iovcc";
+        gpios = <&wsgpio 4 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+    };
+
+    panel_vcc: regulator-panel-vcc {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-vcc";
+        gpios = <&wsgpio 8 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+        regulator-always-on;
+    };
+
+    dsi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        panel@0 {
+            reg = <0>;
+            compatible = "waveshare,8.0-dsi-touch-a", "jadard,jd9365da-h3";
+            reset-gpios = <&wsgpio 1 GPIO_ACTIVE_LOW>;
+            vdd-supply = <&panel_avdd>;
+            vccio-supply = <&panel_iovcc>;
+            backlight = <&wsgpio>;
+
+            port {
+                  panel_in: endpoint {
+                      remote-endpoint = <&dsi_out>;
+                  };
+            };
+        };
+
+        port {
+            dsi_out: endpoint {
+                data-lanes = <0 1 2 3>;
+                remote-endpoint = <&panel_in>;
+            };
+        };
+    };
+...

-- 
2.47.3