-typedef volatile struct NS16550 *NS16550_t;
-
-#define FCR_FIFO_EN 0x01 /* Fifo enable */
-#define FCR_RXSR 0x02 /* Receiver soft reset */
-#define FCR_TXSR 0x04 /* Transmitter soft reset */
-
-#define MCR_DTR 0x01
-#define MCR_RTS 0x02
-#define MCR_DMA_EN 0x04
-#define MCR_TX_DFR 0x08
-#define MCR_LOOP 0x10 /* Enable loopback test mode */
-
-#define LCR_WLS_MSK 0x03 /* character length select mask */
-#define LCR_WLS_5 0x00 /* 5 bit character length */
-#define LCR_WLS_6 0x01 /* 6 bit character length */
-#define LCR_WLS_7 0x02 /* 7 bit character length */
-#define LCR_WLS_8 0x03 /* 8 bit character length */
-#define LCR_STB 0x04 /* Number of stop Bits, off = 1, on = 1.5 or 2) */
-#define LCR_PEN 0x08 /* Parity eneble */
-#define LCR_EPS 0x10 /* Even Parity Select */
-#define LCR_STKP 0x20 /* Stick Parity */
-#define LCR_SBRK 0x40 /* Set Break */
-#define LCR_BKSE 0x80 /* Bank select enable */
-#define LCR_DLAB 0x80 /* Divisor latch access bit */
-
-#define LSR_DR 0x01 /* Data ready */
-#define LSR_OE 0x02 /* Overrun */
-#define LSR_PE 0x04 /* Parity error */
-#define LSR_FE 0x08 /* Framing error */
-#define LSR_BI 0x10 /* Break */
-#define LSR_THRE 0x20 /* Xmit holding register empty */
-#define LSR_TEMT 0x40 /* Xmitter empty */
-#define LSR_ERR 0x80 /* Error */
-
-#define MSR_DCD 0x80 /* Data Carrier Detect */
-#define MSR_RI 0x40 /* Ring Indicator */
-#define MSR_DSR 0x20 /* Data Set Ready */
-#define MSR_CTS 0x10 /* Clear to Send */
-#define MSR_DDCD 0x08 /* Delta DCD */
-#define MSR_TERI 0x04 /* Trailing edge ring indicator */
-#define MSR_DDSR 0x02 /* Delta DSR */
-#define MSR_DCTS 0x01 /* Delta CTS */
+typedef struct NS16550 *NS16550_t;
+
+/*
+ * These are the definitions for the FIFO Control Register
+ */
+#define UART_FCR_FIFO_EN 0x01 /* Fifo enable */
+#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
+#define UART_FCR_CLEAR_XMIT 0x04 /* Clear the XMIT FIFO */
+#define UART_FCR_DMA_SELECT 0x08 /* For DMA applications */
+#define UART_FCR_TRIGGER_MASK 0xC0 /* Mask for the FIFO trigger range */
+#define UART_FCR_TRIGGER_1 0x00 /* Mask for trigger set at 1 */
+#define UART_FCR_TRIGGER_4 0x40 /* Mask for trigger set at 4 */
+#define UART_FCR_TRIGGER_8 0x80 /* Mask for trigger set at 8 */
+#define UART_FCR_TRIGGER_14 0xC0 /* Mask for trigger set at 14 */
+
+#define UART_FCR_RXSR 0x02 /* Receiver soft reset */
+#define UART_FCR_TXSR 0x04 /* Transmitter soft reset */
+
+/*
+ * These are the definitions for the Modem Control Register
+ */
+#define UART_MCR_DTR 0x01 /* DTR */
+#define UART_MCR_RTS 0x02 /* RTS */
+#define UART_MCR_OUT1 0x04 /* Out 1 */
+#define UART_MCR_OUT2 0x08 /* Out 2 */
+#define UART_MCR_LOOP 0x10 /* Enable loopback test mode */
+
+#define UART_MCR_DMA_EN 0x04
+#define UART_MCR_TX_DFR 0x08
+
+/*
+ * These are the definitions for the Line Control Register
+ *
+ * Note: if the word length is 5 bits (UART_LCR_WLEN5), then setting
+ * UART_LCR_STOP will select 1.5 stop bits, not 2 stop bits.
+ */
+#define UART_LCR_WLS_MSK 0x03 /* character length select mask */
+#define UART_LCR_WLS_5 0x00 /* 5 bit character length */
+#define UART_LCR_WLS_6 0x01 /* 6 bit character length */
+#define UART_LCR_WLS_7 0x02 /* 7 bit character length */
+#define UART_LCR_WLS_8 0x03 /* 8 bit character length */
+#define UART_LCR_STB 0x04 /* # stop Bits, off=1, on=1.5 or 2) */
+#define UART_LCR_PEN 0x08 /* Parity eneble */
+#define UART_LCR_EPS 0x10 /* Even Parity Select */
+#define UART_LCR_STKP 0x20 /* Stick Parity */
+#define UART_LCR_SBRK 0x40 /* Set Break */
+#define UART_LCR_BKSE 0x80 /* Bank select enable */
+#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
+
+/*
+ * These are the definitions for the Line Status Register
+ */
+#define UART_LSR_DR 0x01 /* Data ready */
+#define UART_LSR_OE 0x02 /* Overrun */
+#define UART_LSR_PE 0x04 /* Parity error */
+#define UART_LSR_FE 0x08 /* Framing error */
+#define UART_LSR_BI 0x10 /* Break */
+#define UART_LSR_THRE 0x20 /* Xmit holding register empty */
+#define UART_LSR_TEMT 0x40 /* Xmitter empty */
+#define UART_LSR_ERR 0x80 /* Error */
+
+#define UART_MSR_DCD 0x80 /* Data Carrier Detect */
+#define UART_MSR_RI 0x40 /* Ring Indicator */
+#define UART_MSR_DSR 0x20 /* Data Set Ready */
+#define UART_MSR_CTS 0x10 /* Clear to Send */
+#define UART_MSR_DDCD 0x08 /* Delta DCD */
+#define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */
+#define UART_MSR_DDSR 0x02 /* Delta DSR */
+#define UART_MSR_DCTS 0x01 /* Delta CTS */
+
+/*
+ * These are the definitions for the Interrupt Identification Register
+ */
+#define UART_IIR_NO_INT 0x01 /* No interrupts pending */
+#define UART_IIR_ID 0x06 /* Mask for the interrupt ID */
+
+#define UART_IIR_MSI 0x00 /* Modem status interrupt */
+#define UART_IIR_THRI 0x02 /* Transmitter holding register empty */
+#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
+#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
+
+/*
+ * These are the definitions for the Interrupt Enable Register
+ */
+#define UART_IER_MSI 0x08 /* Enable Modem status interrupt */
+#define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */
+#define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */
+#define UART_IER_RDI 0x01 /* Enable receiver data interrupt */
+