[PATCH v2 0/2] arm64: dts: mediatek: mt8395-radxa-nio-12l: Enable i2c3 on 40-pin header

[Ricardo Pardini via B4 Relay]

The Radxa NIO 12L exposes i2c3 (SDA3/SCL3, GPIO14/GPIO15) on its 40-pin
GPIO header, on the blue-colored pins 27 (SCL3) and 28 (SDA3).

Enable the i2c3 controller, add the matching pinctrl configuration and run
the bus at 400 kHz, matching the other I2C buses already enabled on this
board.

While at it, drop a pre-existing redundant drive-strength from i2c2_pins
that was also about to be copied into i2c3: specifying both drive-strength
(mA) and drive-strength-microamp (uA) makes the generic pinconf parser log
"cannot have multiple drive strength properties" at boot, and the advanced
(uA) setting wins in hardware, leaving the mA value dead.

Tested using a SD1306 I2C OLED display.

---
Changes in v2:
- Add a drive-by patch dropping the redundant drive-strength in i2c2_pins
  (via Claude, reported by Sashiko).
- i2c3: use only drive-strength-microamp, as per Sashiko's review.
- Link to v1: https://patch.msgid.link/20260624-nio-12l-add-i2c-40-pin-v1-1-f6c11ed2184c@xxxxxxxxxxx

To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Matthias Brugger <matthias.bgg@xxxxxxxxx>
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Ricardo Pardini <ricardo@xxxxxxxxxxx>

---
Ricardo Pardini (2):
      arm64: dts: mediatek: mt8395-radxa-nio-12l: Drop redundant i2c2 drive-strength
      arm64: dts: mediatek: mt8395-radxa-nio-12l: Enable i2c3 on 40-pin header

 arch/arm64/boot/dts/mediatek/mt8395-radxa-nio-12l.dts | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)
---
base-commit: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
change-id: 20260624-nio-12l-add-i2c-40-pin-19e0482fd835

Best regards,
--  
Ricardo Pardini <ricardo@xxxxxxxxxxx>