dt-bindings: trigger-source: add generic GPIO trigger source

Inspired by pwm-trigger, create a new binding for using a GPIO
line as a trigger source.

Link: https://lore.kernel.org/linux-iio/20250207-dlech-mainline-spi-engine-offload-2-v8-3-e48a489be48c@baylibre.com/
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
Link: https://patch.msgid.link/c4a3a7c828c711b439d1893271b8376823176ea6.1749569957.git.Jonathan.Santos@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml

@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/trigger-source/gpio-trigger.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic trigger source using GPIO
+
+description: A GPIO used as a trigger source.
+
+maintainers:
+  - Jonathan Santos <Jonathan.Santos@analog.com>
+
+properties:
+  compatible:
+    const: gpio-trigger
+
+  '#trigger-source-cells':
+    const: 0
+
+  gpios:
+    maxItems: 1
+    description: GPIO to be used as a trigger source.
+
+required:
+  - compatible
+  - '#trigger-source-cells'
+  - gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    trigger {
+        compatible = "gpio-trigger";
+        #trigger-source-cells = <0>;
+        gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
+    };

MAINTAINERS

@@ -25203,9 +25203,10 @@ W:	https://github.com/srcres258/linux-doc
 T:	git git://github.com/srcres258/linux-doc.git doc-zh-tw
 F:	Documentation/translations/zh_TW/
 
-TRIGGER SOURCE - PWM
+TRIGGER SOURCE
 M:	David Lechner <dlechner@baylibre.com>
 S:	Maintained
+F:	Documentation/devicetree/bindings/trigger-source/gpio-trigger.yaml
 F:	Documentation/devicetree/bindings/trigger-source/pwm-trigger.yaml
 
 TRUSTED SECURITY MODULE (TSM) INFRASTRUCTURE