imx8qxp sc16is750 ==> I can't see ttySC0

[yoonseok]

Hello, I'm asking for help because I have a problem.


From imx8qxp chip, use sc16is750
I want to implement i2c to uart.


The following was added to file imx8x-mek-rpmsg.dtsi.

sc16is750: sc16is750@4d {
        compatible = "nxp,sc16is750";
        reg = <0x4d>;
        clocks = <&sc16is750_clk>;
        interrupt-parent = <&lsio_gpio1>;
         interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
        gpio-controller;
        #gpio-cells = <2>;
       

        sc16is750_clk: sc16is750_clk {
                       compatible = "fixed-clock";
                      #clock-cells = <0>;
                      clock-frequency = <7372800>;
           };
};

When the system boots, the following message appears.
serial serial0: tty port ttySC0 registered

After the system boot,
ttySC0 is not visible in the /dev directory.

For reference, the gpio function added to sc16is750 operates normally.

What's the problem? Please help me.

[igorpadykov]

Hi Yoonseok

for this case may be recommended to check if i2c is not owned by m4 resource, as in below

example (i2c1)

https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8x-mek-rp...

In such case one can move i2c resource to A core as in below example sect."Modifying default configuration" (moving FlexCAN resources from the M4 partition to the A cores partition)

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/System-Controller-Firmware-101-Resource-...

Or try to use dts without "rpmsg", not use m4 core.

Best regards
igor

[yoonseok]

It was solved thanks to you.Thank you.