dt-bindings: pincfg-node: Add input-threshold-voltage-microvolt property

Add a generic pin configuration property
"input-threshold-voltage-microvolt" to support hardware designs where the
input logic threshold is decoupled from the power supply voltage.

This property allows the pinctrl driver to configure the correct internal
reference voltage for pins that need to accept input signals at a different
voltage level than their power supply. For example, a pin powered by 3.3V
may need to accept 1.8V logic signals.

This defines the reference for VIH (Input High Voltage) and VIL (Input Low
Voltage) thresholds, enabling proper signal detection across different
voltage domains.

Signed-off-by: Tzuyi Chang <tychang@realtek.com>
Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com>
Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>

diff --git a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
index 981f45c2f56b01af8d487156bbd0f73169309a72..97dbce8a261f2bfcf9cb78eb196f1c4aa12e1cb8 100644 (file)
--- a/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
@@ -162,6 +162,11 @@ properties:
       this affects the expected delay in ps before latching a value to
       an output pin.
 
+  input-threshold-voltage-microvolt:
+    description: Specifies the input voltage level of the pin in microvolts.
+      This defines the reference for  VIH (Input High Voltage) and VIL
+      (Input Low Voltage) thresholds for proper signal detection.
+
 allOf:
   - if:
       required:
@@ -177,6 +182,7 @@ allOf:
     then:
       properties:
         input-enable: false
+        input-threshold-voltage-microvolt: false
 
   - if:
       required: