ASoC: dt-bindings: sun50i-codec: Add binding for internal bias

In order to properly bias headset microphones, there should be a pull-up
resistor between pins HBIAS and MIC2P. This can be an external resistor,
but the codec also provides an internal 2.2K resistor which is enabled
by a register.

This patch adds a device-tree property to the sun50i-codec-analog driver
to take advantage of this feature.

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
[Samuel: split binding and implementation patches]
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220621035452.60272-2-samuel@sholland.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/Documentation/devicetree/bindings/sound/allwinner,sun50i-a64-codec-analog.yaml b/Documentation/devicetree/bindings/sound/allwinner,sun50i-a64-codec-analog.yaml
index 3b764415c9abf7a696c7f965cbb36abfac4264d0..66859eb8f79ab1df66b486579a2273d030f771f0 100644 (file)
--- a/Documentation/devicetree/bindings/sound/allwinner,sun50i-a64-codec-analog.yaml
+++ b/Documentation/devicetree/bindings/sound/allwinner,sun50i-a64-codec-analog.yaml
@@ -21,6 +21,11 @@ properties:
     description:
       Regulator for the headphone amplifier
 
+  allwinner,internal-bias-resistor:
+    description:
+      Enable the internal 2.2K bias resistor between HBIAS and MICDET pins
+    type: boolean
+
 required:
   - compatible
   - reg