choice
    prompt "select usart type "
        help
          select usart type
config USART_DW
    bool "designware usart"
    help
        select the dw usart driver

config USART_CK
    bool "csky usart"
    help
        select the ck usart driver
        
config USART_SILAN
    bool "silan usart"
    help
        select the silan usart driver

config USART_ZX29
    bool "zx29 usart"
    help
        select the zx29 usart driver
endchoice