Hi NXP,
We have a custon board and config uart as rs485 + rts-gpio like below and it works well on SDK-5.10.72. (We have modified imx-atf and u-boot to change uart4 for cpu use not mcu)
Now we upgrade to SDK-5.15.32 and also merge this config to 5.15.32 but it has some problem.
We connect to PC and test by minicon.
When we "disable flow control", imx8mp can send characters to PC but cannot receive from PC.
When we "enable flow control", imx8mp can receive characters from PC but cannot send to PC (PC cannot receive from imx8mp).
What do I need to modify for SDK-5.15.32?
pinctrl_uart4: uart4grp {
fsl,pins = <
MX8MP_IOMUXC_UART4_RXD__UART4_DCE_RX 0x00000106
MX8MP_IOMUXC_UART4_TXD__UART4_DCE_TX 0x00000106
MX8MP_IOMUXC_NAND_DATA03__GPIO3_IO09 0x00000106
>;
};
&uart4 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart4>;
assigned-clocks = <&clk IMX8MP_CLK_UART4>;
assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_80M>;
linux,rs485-enabled-at-boot-time;
rts-gpios = <&gpio3 9 GPIO_ACTIVE_HIGH>;
status = "okay";
};
Best Regards,
Sophie
