i.MX ProcessorsのトピックAdditional UART in u-boot

Additional UART in u-boot

david_schmidt — Fri, 21 Sep 2018 12:52:08 GMT

Hi,

I need to use an additional UART interface (UART2) in my case during u-boot to send and recevice data to a peripheral. My u-boot console should still work with my current UART interface (UART1).

I have added my UART2 to my dtsi file:

&uart2 {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_uart2>;
    status = "okay";
};

I suppose I need 3 functions, uart_init, uart_putc and uart_getc.

Can I use the routines from /drivers/serial/serial_mxc.c?

It allows only using one UART interface, defined by

#define UART_PHYS CONFIG_MXC_UART_BASE

Thanks for the help.

Re: Additional UART in u-boot

igorpadykov — Fri, 21 Sep 2018 23:33:47 GMT

Hi David

one can look at implementation of this feature on other boards and post

issue on uboot mail list

[U-Boot] [PATCH 02/18] Blackfin: uart: add multiple serial support

lists.denx.de Mailing Lists

Best regards
igor
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Re: Additional UART in u-boot

david_schmidt — Fri, 28 Sep 2018 12:10:28 GMT

To use an additional UART interface in u-boot, one can copy the functions from /drivers/serial/serial_mxc.c.

The thing I missed was the

imx_iomux_v3_setup_multiple_pads(uart2_pads, ARRAY_SIZE(uart2_pads));

pin initialization in the board.c, but this only works in board_init or board_late_init, and not in board_early_init_f,

After that, the send and receive functions work properly.