dt-bindings: pinctrl: renesas,r9a09g077: Document pin configuration properties

Document the pin configuration properties supported by the RZ/T2H
pinctrl driver.

The RZ/T2H SoC allows configuring several electrical characteristics
through the DRCTLm (I/O Buffer Function Switching) registers. These
registers control drive strength, bias configuration, Schmitt trigger
input, and output slew rate.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260319141515.2053556-2-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,r9a09g077-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/renesas,r9a09g077-pinctrl.yaml
index f049013a4e0c958932db66605052775020914f57..63993b20524f55e3fb6f21d91659a9ed501e5681 100644 (file)
--- a/Documentation/devicetree/bindings/pinctrl/renesas,r9a09g077-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/renesas,r9a09g077-pinctrl.yaml
@@ -83,6 +83,23 @@ definitions:
       input: true
       input-enable: true
       output-enable: true
+      bias-disable: true
+      bias-pull-down: true
+      bias-pull-up: true
+      input-schmitt-enable: true
+      input-schmitt-disable: true
+      slew-rate:
+        description: 0 is slow slew rate, 1 is fast slew rate
+        enum: [0, 1]
+      drive-strength-microamp:
+        description: |
+          Four discrete levels are supported (via registers DRCTLm), corresponding
+          to the following nominal values:
+          - 2500  (Low strength)
+          - 5000  (Middle strength)
+          - 9000  (High strength)
+          - 11800 (Ultra High strength)
+        enum: [2500, 5000, 9000, 11800]
     oneOf:
       - required: [pinmux]
       - required: [pins]