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UART3, UART4, UART5 on imx6ull

Question asked by Steven Yu on Jan 24, 2018
Latest reply on Aug 20, 2018 by Abhishek Arora

Hi All,

 

We know the i.mx6ull has UART1 and UART2 enabled by default. 

In our board, we would like to use UART4, UART5, and then we have modify the device tree as below.

The result is TX from our board to PC console is OK. But RX from PC console to our board is no action (even no interrupts) Which thing we miss?

 

pinctrl_uart4: uart4grp {
fsl,pins = <
MX6UL_PAD_UART4_TX_DATA__UART4_DCE_TX 0x1b0b1
MX6UL_PAD_UART4_RX_DATA__UART4_DCE_RX 0x1b0b1
>;
};

pinctrl_uart5: uart5grp {
fsl,pins = <
MX6UL_PAD_UART5_TX_DATA__UART5_DCE_TX 0x1b0b1
MX6UL_PAD_UART5_RX_DATA__UART5_DCE_RX 0x1b0b1
>;
};

 

environment:

our board===UART4/UART5===usb2rs232----PC

 

echo "hello" > /dev/ttymxc4 is ok

but cat /dev/ttymxc4 does not receive message from PC teraterm console.

 

Regards,

Stephen 

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