Function esp_idf_sys::cfsetispeed

pub unsafe extern "C" fn cfsetispeed(
    p: *mut termios,
    sp: speed_t
) -> c_int

@brief Set input baud rate in the termios structure

There is no effect in hardware until a subsequent call of tcsetattr().

@param p input termios structure @param sp input baud rate @return 0 when successful, -1 otherwise with errno set