arm64: dts: qcom: qrb4210-rb2: switch I2C2 to i2c-gpio

commit f77e7bd40c3c2d79685e9cc80de874b69a976f55 upstream.

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@vger.kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Link: https://lore.kernel.org/r/20240605-rb12-i2c2g-pio-v2-2-946f5d6b6948@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
index 696d6d43c56b326f5eff21b57cc28daad94c70c1..54d17eca97519edd787cdef83a1f0f749cdbba29 100644 (file)
--- a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
+++ b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
@@ -60,6 +60,17 @@
                };
        };
 
+       i2c2_gpio: i2c {
+               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 @@
        };
 };
 
-&i2c2 {
+&i2c2_gpio {
        clock-frequency = <400000>;
        status = "okay";