[PATCH v3] arm64: dts: qcom: lemans-evk: Enable CAN RX via I2C GPIO expander

[Anup Kulkarni]

The LeMans EVK board routes the RX lines of CAN controllers 2, 4, and 6
(part of the RTSS subsystem) through a signal multiplexer controlled by
GPIO 4 of the I2C GPIO expander at address 0x3b. The remaining CAN
controllers, out of 8 total on RTSS, are wired directly to their
transceivers.

The multiplexer select pin defaults low on reset, disconnecting CAN 2,
4, and 6 RX lines from their respective transceivers, which results in
no data being received on these interfaces.

Configure GPIO 4 as output-high to assert the mux select line at boot,
connecting the RX signals of CAN 2, 4, and 6 to their transceivers as
required by the EVK board wiring.

Signed-off-by: Anup Kulkarni <anup.kulkarni@xxxxxxxxxxxxxxxx>
---
v1->v2
- Fixed commit text to include platform name.

v2->v3
- Updated commit text.
---
 arch/arm64/boot/dts/qcom/lemans-evk.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/lemans-evk.dts b/arch/arm64/boot/dts/qcom/lemans-evk.dts
index c665db6a4595..34dfc8d22b6a 100644
--- a/arch/arm64/boot/dts/qcom/lemans-evk.dts
+++ b/arch/arm64/boot/dts/qcom/lemans-evk.dts
@@ -616,6 +616,13 @@ expander3: gpio@3b {
 		interrupts-extended = <&tlmm 39 IRQ_TYPE_LEVEL_LOW>;
 		pinctrl-0 = <&expander3_int>;
 		pinctrl-names = "default";
+
+		rtss-can-sel-hog {
+			gpio-hog;
+			gpios = <4 GPIO_ACTIVE_HIGH>;
+			output-high;
+			line-name = "rtss-can-sel";
+		};
 	};
 
 	eeprom@50 {
-- 
2.34.1