ar933x_uart_get_baud
diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);