There is an Errata with the built-in I2C controller where various I2C hardware errors cause a complete lockup of the CPU (which eventually results in an watchdog reset).
Put the I2C MPP pins into GPIO mode and use the i2c-gpio driver instead. This uses a bit-banged implementation of an I2C controller and avoids triggering the Errata. Signed-off-by: Chris Packham <judge.pack...@gmail.com> --- This is dependent on a bug-fix for the i2c-gpio driver I just sent out[1] (sorry I should have sent them as a series but I thought this would take me longer to test than it did). [1] - https://lore.kernel.org/u-boot/20230720023107.1184147-1-judge.pack...@gmail.com/ arch/arm/dts/ac5-98dx35xx-atl-x240.dts | 30 ++++++++++++++++++++++---- configs/x240_defconfig | 1 + 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/arch/arm/dts/ac5-98dx35xx-atl-x240.dts b/arch/arm/dts/ac5-98dx35xx-atl-x240.dts index 820ec18b4355..d47220520b9e 100644 --- a/arch/arm/dts/ac5-98dx35xx-atl-x240.dts +++ b/arch/arm/dts/ac5-98dx35xx-atl-x240.dts @@ -71,8 +71,25 @@ }; &i2c0 { - status = "okay"; + status = "disabled"; +}; +&{/} { + i2cgpio: i2c-gpio-0 { + compatible = "i2c-gpio"; + #address-cells = <1>; + #size-cells = <0>; + + pinctrl-names = "default"; + pinctrl-0 = <&i2c0_gpio>; + scl-gpios = <&gpio0 26 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; + sda-gpios = <&gpio0 27 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; + i2c-gpio,delay-us = <2>; + status = "okay"; + }; +}; + +&i2cgpio { mux@71 { #address-cells = <1>; #size-cells = <0>; @@ -177,8 +194,8 @@ * LED_OE_N [23] * USB_PWR_FLT_N [24] * SFP_INT_N [25] - * I2C0_SCL [26] - * I2C0_SDA [27] + * I2C0_SCL [26] (GPIO) + * I2C0_SDA [27] (GPIO) * USB_EN [28] * MONITOR_INT_N [29] * XM1_MDC [30] @@ -201,7 +218,7 @@ /* 0 1 2 3 4 5 6 7 8 9 */ pin-func = < 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 0xff 1 1 1 1 0xff 0xff 0 0 - 0 0 0 0 0 0 1 1 0 0 + 0 0 0 0 0 0 0xff 0xff 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 1 1 1 >; @@ -209,4 +226,9 @@ marvell,pins = <0 1 2 3 4 5 6 7 8 9 10 11 16 17>; marvell,function = <2>; }; + + i2c0_gpio: i2c0-gpio-pins { + marvell,pins = <26 27>; + marvell,function = <0>; + }; }; diff --git a/configs/x240_defconfig b/configs/x240_defconfig index 6d25c5ae3fcf..e8589d636081 100644 --- a/configs/x240_defconfig +++ b/configs/x240_defconfig @@ -43,6 +43,7 @@ CONFIG_CLK_MVEBU=y CONFIG_GPIO_HOG=y CONFIG_DM_PCA953X=y CONFIG_DM_I2C=y +CONFIG_DM_I2C_GPIO=y CONFIG_SYS_I2C_MVTWSI=y CONFIG_I2C_MUX=y CONFIG_I2C_MUX_PCA954x=y -- 2.41.0
