Hello,
Everything is validated on our IMX6UL, but we are facing a problem with I2C3.
With IOMux, we activated I2C3 with pads SCL W17 and SDA W19. Each routed with a pull-up 2.2k resistor, to 3.3V.
While validating I2C with a simple slave, we discovered that the I2C voltages SDA and SCL were falling down when we did “ifconfig eth0 up” rising back to normal when we did “ifconfig eth0 down”.
The I2C communication was very noisy and unusable when the eth0 interface was up.
We tried again without any slave connected, just monitoring the SCL and SDA voltages, and the problem was still present.
Here are the concerned portions of the device tree :
&i2c3 {
pinctrl-names = “default”;
pinctrl-0 = <&pinctrl_i2c3>;
/* Uncomment and fill with your current scl/sda lines. */
//scl-gpios = <&gpio3 8 GPIO_ACTIVE_HIGH>;
//sda-gpios = <&gpio3 7 GPIO_ACTIVE_HIGH>;
status = "okay";
};
pinctrl_i2c3: i2c3grp {
fsl,pins = <
MX6UL_PAD_ENET2_RX_DATA0__I2C3_SCL 0x4001b8b0
MX6UL_PAD_ENET2_RX_DATA1__I2C3_SDA 0x4001b8b0
>;
};
&fec1 {
pinctrl-names = “default”;
pinctrl-0 = <&pinctrl_enet1>, <&pinctrl_enet_mdio>;
phy-mode = “rmii”;
phy-handle = <ðphy1>;
/*
* Optional fields.
*
* Configure the PHY reset with a GPIO in your design.
*/
//phy-reset-gpios = <&gpio5 6 GPIO_ACTIVE_LOW>
//phy-reset-duration = <26>;
//digi,phy-reset-in-suspend;
status = "okay";
mdio {
#address-cells = <1>;
#size-cells = <0>;
ethphy1: ethernet-phy@0 {
compatible = "ethernet-phy-ieee802.3-c22";
/*
* Add your custom PHY configuration.
*/
//smsc,disable-energy-detect;
reg = <0>;
};
};
};
pinctrl_enet1: enet1grp {
fsl,pins = <
MX6UL_PAD_ENET1_RX_DATA0__ENET1_RDATA00 0x1b0b0
MX6UL_PAD_ENET1_RX_DATA1__ENET1_RDATA01 0x1b0b0
MX6UL_PAD_ENET1_RX_EN__ENET1_RX_EN 0x1b0b0
MX6UL_PAD_ENET1_RX_ER__ENET1_RX_ER 0x1b0b0
MX6UL_PAD_ENET1_TX_DATA0__ENET1_TDATA00 0x1b0b0
MX6UL_PAD_ENET1_TX_DATA1__ENET1_TDATA01 0x1b0b0
MX6UL_PAD_ENET1_TX_CLK__ENET1_REF_CLK1 0x4001b031
MX6UL_PAD_ENET1_TX_EN__ENET1_TX_EN 0x1b0b0
>;
};
pinctrl_enet_mdio: mdioenetgrp {
fsl,pins = <
MX6UL_PAD_GPIO1_IO07__ENET1_MDC 0x1b0b0
MX6UL_PAD_GPIO1_IO06__ENET1_MDIO 0x1b0b0
>;
};
Regards,
Mathieu GALLE, Vitirover