regulator: dt-bindings: document the SGM3804 Dual Output regulator

Document the SG Micro SGM3804 Single Inductor Dual Output Buck/Boost
Converter used to power LCD panels a provide positive and negative
power rails with configurable voltage and active discharge function
for each output.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260522-topic-sm8650-ayaneo-pocket-s2-sgm3804-v5-1-bd6b1c300ecc@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/sgmicro,sgm3804.yaml

@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/sgmicro,sgm3804.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SG Micro SGM3804 Single Inductor Dual Output Buck/Boost Converter
+
+maintainers:
+  - Neil Armstrong <neil.armstrong@linaro.org>
+
+description:
+  The SGM3804 is a dual voltage regulator, designed to support positive/negative
+  supply for driving LCD panels. It support software-configurable output
+  switching. The output voltages can be programmed via an I2C compatible interface.
+
+properties:
+  compatible:
+    const: sgmicro,sgm3804
+
+  reg:
+    maxItems: 1
+
+  vin-supply: true
+
+patternProperties:
+  "^(pos|neg)$":
+    type: object
+    $ref: regulator.yaml#
+
+    properties:
+      enable-gpios: true
+
+    unevaluatedProperties: false
+
+    required:
+      - enable-gpios
+
+required:
+  - compatible
+  - reg
+  - pos
+  - neg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@3e {
+            compatible = "sgmicro,sgm3804";
+            reg = <0x3e>;
+
+            vin-supply = <&vin_reg>;
+
+            pos {
+                regulator-name = "outpos";
+                regulator-min-microvolt = <5000000>;
+                regulator-max-microvolt = <5000000>;
+                enable-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
+            };
+
+            neg {
+                regulator-name = "outneg";
+                regulator-min-microvolt = <5000000>;
+                regulator-max-microvolt = <5000000>;
+                enable-gpios = <&gpio 18 GPIO_ACTIVE_HIGH>;
+            };
+        };
+    };
+...
+