10 Apr, 2017

1 commit

  • Add a specific serial driver for Intel MID platforms.

    It has special fractional divider which can be programmed via UART_PS,
    UART_MUL, and UART_DIV registers.

    The UART clock is calculated as

    UART clock = XTAL * UART_MUL / UART_DIV

    The baudrate is calculated as

    baud rate = UART clock / UART_PS / DLAB

    Initialize fractional divider correctly for Intel Edison platform.

    For backward compatibility we have to set initial DLAB value to 16
    and speed to 115200 baud, where initial frequency is 29491200Hz, and
    XTAL frequency is 38.4MHz.

    Signed-off-by: Andy Shevchenko
    Reviewed-by: Simon Glass
    Reviewed-by: Kever Yang

    Andy Shevchenko