Function uart_drv_cmd 

pub unsafe extern "C" fn uart_drv_cmd(
    dev: *const device,
    cmd: u32,
    p: u32,
) -> c_int

@brief Send extra command to driver.

Implementation and accepted commands are driver specific. Refer to the drivers for more information.

@param dev UART device instance. @param cmd Command to driver. @param p Parameter to the command.

@return 0 on success, negative errno value on failure. @retval -ENOSYS Function is not implemented. @retval -ENOTSUP API is not enabled.