Hi,
I am currently trying to set up an RS485 line using the lpuart2 and lpuart7. In my device tree i added the lines:
&iomuxc {
pinctrl_uart2: uart2grp { // RS485_1
fsl,pins = <
MX93_PAD_UART2_RXD__LPUART2_RX 0x31e
MX93_PAD_UART2_TXD__LPUART2_TX 0x31e
MX93_PAD_SAI1_TXC__LPUART2_CTS_B 0x31e
>;
};
pinctrl_uart7: uart7grp { // RS485_2
fsl,pins = <
MX93_PAD_GPIO_IO08__LPUART7_TX 0x31e // TX
MX93_PAD_GPIO_IO09__LPUART7_RX 0x31e // RX
MX93_PAD_GPIO_IO10__LPUART7_CTS_B 0x31e // DE
>;
};
};
for the pin control and these:
&lpuart2 { // RS485_1 pin: p1-72[TX] p1-19[RX] p1-53[DE]
fsl,uart-has-rtscts;
rts-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>;
linux,rs485-enabled-at-boot-time; // rs485 abilitata fin da subito al boot
rs485-rts-active-high;
rs485-rts-delay = <1 1>;
};
&lpuart7 { // RS485_2 pin: p1-39[TX] p1-41[RX] p1-37[DE]
uart-has-rtscts;
rts-gpios = <&gpio2 7 GPIO_ACTIVE_HIGH>;
linux,rs485-enabled-at-boot-time; // rs485 abilitata fin da subito al boot
rs485-rts-active-high;
rs485-rts-delay = <1 1>;
};
For the peripherals.
I am trying to test the RS485 with a python script. I am currently able to write, but I am not able to read; that is because RTS pin always high. I haven't find a way to make the machine use in the correct way the RTS/CTS pin from the som.
I checked the compatible is the imx93.dtsi file and it seems that the corresponding driver [fsl_lpuart.c] never access the device tree. Instead i have seen that the driver [imx.c] load from device tree some settings about RS485. Is it possible that there are some correlations? Do you know how can i configure the device tree (or the python script in order to make things work?
I attach all the device tree used in the board and the python script used for test.
Thank you in advance
Best regards
Lorenzo
