/* Output a character in polled mode. 
Writes data to tx register if transmitter is not full. */
static void uart_sifive_poll_out(const struct device *dev, unsigned char c)
/* Output a character in polled mode. 
Writes data to tx register if transmitter is not full. */
static void uart_sifive_poll_out(const struct device *dev, unsigned char c)
{
	volatile struct uart_sifive_regs_t *uart = DEV_UART(dev);
	while (uart->tx & TXDATA_FULL) {
	}
	uart->tx = (int)c;
}