how to enable UART4 and UART5 ??

[cw_lee]

Hi, all

I added configuraion to enable UART4 / UART5.

(Ref: http://variwiki.com/index.php?title=DART-6UL_UART)

It's not working if I use imx6ull-var-dart-5g-emmc_wifi.dtb (ttymxc3, ttymxc4 are not loaded)

But it's working if I use imx6ull-var-dart-5g-sd-emmc.dtb (ttymxc3, ttymxc4 are loaded)

do you know why?

please check my dtsi file.

I added only below for UART4 / UART5

--------------------------------------------------------

/* ttymxc3 UART  */
&uart4 {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_uart4>;
   fsl,uart-has-rtscts;
    status = "okay"; 
};

/* ttymxc4 UART  */
&uart5 {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_uart5>;
   fsl,uart-has-rtscts;
    status = "okay"; 
};

    pinctrl_uart4: uart4grp {
        fsl,pins = <
            MX6UL_PAD_LCD_CLK__UART4_DCE_TX      0x1b0b1 
            MX6UL_PAD_LCD_ENABLE__UART4_DCE_RX   0x1b0b1
MX6UL_PAD_LCD_HSYNC__UART4_DCE_CTS   0x1b0b1
MX6UL_PAD_LCD_VSYNC__UART4_DCE_RTS   0x1b0b1
        >;      
    };
   
    pinctrl_uart5: uart5grp {
        fsl,pins = <
            MX6UL_PAD_CSI_DATA00__UART5_DCE_TX   0x1b0b1
            MX6UL_PAD_CSI_DATA01__UART5_DCE_RX   0x1b0b1
MX6UL_PAD_CSI_DATA03__UART5_DCE_CTS  0x1b0b1
MX6UL_PAD_CSI_DATA02__UART5_DCE_RTS  0x1b0b1
        >;
    };

and disable &lcdif configuration because of LCD_CLK / LCD_ENABLE.

my board: DART-6UL-5G (CPU: i.MX6ULL)

[CarlosCasillas]

Hi Lee,

If you are using a Variscite board, you should directly contact with Variscite:

Variscite Support Center - Variscite 

Anyway, as general recommendations, to enable a peripheral, it is required to have the proper driver enabled by the kernel or as module, and also consider it as enabled/maped on the Device Tree, and such configuration should match with the pin muxing to ensure proper functionality of the peripheral.

Hope this will be useful for you.
Best regards!
/Carlos
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