[PATCH 2/2] arm64: dts: qcom: qrb4210-rb2: switch I2C2 to i2c-gpio

From: Dmitry Baryshkov
Date: Tue Jun 04 2024 - 06:15:37 EST


On the Qualcomm RB2 platform the I2C bus connected to the LT9611UXC
bridge under some circumstances can go into a state when all transfers
timeout. This causes both issues with fetching of EDID and with
updating of the bridge's firmware. While we are debugging the issue,
switch corresponding I2C bus to use i2c-gpio driver. While using
i2c-gpio no communication issues are observed.

This patch is asusmed to be a temporary fix, so it is implemented in a
non-intrusive manner to simply reverting it later.

Fixes: f7b01e07e89c ("arm64: dts: qcom: qrb4210-rb2: Enable display out")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/qrb4210-rb2.dts | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
index 2c39bb1b97db..5bfbd81db032 100644
--- a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
+++ b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
@@ -60,6 +60,17 @@ hdmi_con: endpoint {
};
};

+ i2c2_gpio: i2c2-gpio {
+ compatible = "i2c-gpio";
+
+ sda-gpios = <&tlmm 6 GPIO_ACTIVE_HIGH>;
+ scl-gpios = <&tlmm 7 GPIO_ACTIVE_HIGH>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ status = "disabled";
+ };
+
leds {
compatible = "gpio-leds";

@@ -190,7 +201,7 @@ zap-shader {
};
};

-&i2c2 {
+&i2c2_gpio {
clock-frequency = <400000>;
status = "okay";


--
2.39.2