Hello,
I am trying to use uart3 on sabresd board from the GPS pads present on the boards. My board doesn't have a GPS module installed so I have soldered wires of RX TX on the board.
I put following configuration in the imx6qdl-sabresd.dtsi file and the loopback testing using echo/cat works Perfect.
pinctrl_uart3: uart3grp {
fsl,pins = <
MX6QDL_PAD_EIM_D25__UART3_RX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D24__UART3_TX_DATA 0x1b0b1
>;
};
&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3>;
status = "okay";
};
But I want to use hardware flow control and when I put the following configurations the UART3 doesn't work. No response of loopback is received.
pinctrl_uart3_1: uart3grp-1 {
fsl,pins = <
MX6QDL_PAD_EIM_D25__UART3_RX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D24__UART3_TX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D23__UART3_CTS_B 0x1b0b1
MX6QDL_PAD_EIM_D31__UART3_RTS_B 0x1b0b1
>;
};
pinctrl_uart3dte_1: uart3dtegrp-1 {
fsl,pins = <
MX6QDL_PAD_EIM_D25__UART3_TX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D24__UART3_RX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D31__UART3_CTS_B 0x1b0b1
MX6QDL_PAD_EIM_D23__UART3_RTS_B 0x1b0b1
>;
};
&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3_1>;
fsl,uart-has-rtscts;
status = "okay";
};
Please help me with the problem . Thanks@
Hi muhammad
one can check if flow signals direction is correct using
Table 86. UART I/O Configuration vs. Mode i.MX6DQ Datasheet
http://www.nxp.com/docs/en/data-sheet/IMX6DQCEC.pdf
and verify operation with baremetal test Github SDK
https://github.com/backenklee/swp-report/tree/master/iMX6_Platform_SDK
Best regards
igor
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Hi Igor,
I have got it working. I figured out the problem was with MX6QDL_PAD_EIM_D23_ was already being used for other device. (imx6qdl-sabresd { pinctrl_hog: hoggrp ).
I removed it from there and the UART3 works perfect now. Thank you so much for your time and help.
Best Regards,
Muhammad Awais
Hi Igor,
thanks for your reply, I have tested it with different direction setting but it isn't working. Actually I guess the direction doesn't matter for now as I haven't connected with any other device. I am just checking the loopback.(shorting RX/TX CTS/RTS with each other). So regardless of the direction settings it should respond?
Best Regards,
Muhammad Awais.