ASoC: dt-bindings: samsung,midas-audio: Add GPIO-based headset jack detection

Some Samsung devices that share the midas-audio driver use a GPIO-based
approach to headset jack detection, as opposed to using the built-in
jack detection provided by the wm8994 driver. This setup uses two GPIOs
(one for jack detection and another for key detection) and an ADC
channel for determining the jack type or button pressed.

Add DT configuration values that allow for describing these setups.
Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://msgid.link/r/20240525-midas-wm1811-gpio-jack-v4-2-f488e03bd8c7@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/samsung,midas-audio.yaml

@@ -64,6 +64,36 @@ properties:
     maxItems: 1
     description: GPIO pin for line out selection
 
+  headset-detect-gpios:
+    maxItems: 1
+    description: GPIO for detection of headset insertion
+
+  headset-key-gpios:
+    maxItems: 1
+    description: GPIO for detection of headset key press
+
+  io-channels:
+    maxItems: 1
+    description: IO channel to read micbias voltage for headset detection
+
+  io-channel-names:
+    const: headset-detect
+
+  samsung,headset-4pole-threshold-microvolt:
+    minItems: 2
+    maxItems: 2
+    description:
+      Array containing minimum and maximum IO channel value for 4-pole
+      (with microphone/button) headsets. If the IO channel value is
+      outside of this range, a 3-pole headset is assumed.
+
+  samsung,headset-button-threshold-microvolt:
+    minItems: 3
+    maxItems: 3
+    description: |
+      Array of minimum (inclusive) IO channel values for headset button
+      detection, in order: "Media", "Volume Up" and "Volume Down".
+
 required:
   - compatible
   - cpu