include/ns16550.h

/*
 * NS16550 Serial Port
 * originally from linux source (arch/powerpc/boot/ns16550.h)
 *
 * Cleanup and unification
 * (C) 2009 by Detlev Zundel, DENX Software Engineering GmbH
 *
 * modified slightly to
 * have addresses as offsets from CONFIG_SYS_ISA_BASE
 * added a few more definitions
 * added prototypes for ns16550.c
 * reduced no of com ports to 2
 * modifications (c) Rob Taylor, Flying Pig Systems. 2000.
 *
 * added support for port on 64-bit bus
 * by Richard Danter (richard.danter@windriver.com), (C) 2005 Wind River Systems
 */

/*
 * Note that the following macro magic uses the fact that the compiler
 * will not allocate storage for arrays of size 0
 */

#include <linux/types.h>

#if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
#error "Please define NS16550 registers size."
#elif defined(CONFIG_SYS_NS16550_MEM32)
#define UART_REG(x) u32 x
#elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
#define UART_REG(x)						   \
	unsigned char prepad_##x[CONFIG_SYS_NS16550_REG_SIZE - 1]; \
	unsigned char x;
#elif (CONFIG_SYS_NS16550_REG_SIZE < 0)
#define UART_REG(x)							\
	unsigned char x;						\
	unsigned char postpad_##x[-CONFIG_SYS_NS16550_REG_SIZE - 1];
#endif

struct NS16550 {
	UART_REG(rbr);		/* 0 */
	UART_REG(ier);		/* 1 */
	UART_REG(fcr);		/* 2 */
	UART_REG(lcr);		/* 3 */
	UART_REG(mcr);		/* 4 */
	UART_REG(lsr);		/* 5 */
	UART_REG(msr);		/* 6 */
	UART_REG(spr);		/* 7 */
#ifdef CONFIG_SOC_DA8XX
	UART_REG(reg8);		/* 8 */
	UART_REG(reg9);		/* 9 */
	UART_REG(revid1);	/* A */
	UART_REG(revid2);	/* B */
	UART_REG(pwr_mgmt);	/* C */
	UART_REG(mdr1);		/* D */
#else
	UART_REG(mdr1);		/* 8 */
	UART_REG(reg9);		/* 9 */
	UART_REG(regA);		/* A */
	UART_REG(regB);		/* B */
	UART_REG(regC);		/* C */
	UART_REG(regD);		/* D */
	UART_REG(regE);		/* E */
	UART_REG(uasr);		/* F */
	UART_REG(scr);		/* 10*/
	UART_REG(ssr);		/* 11*/
#endif
};

#define thr rbr
#define iir fcr
#define dll rbr
#define dlm ier

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_AFE	0x20		/* Enable auto-RTS/CTS */

#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 */

/* useful defaults for LCR */
#define UART_LCR_8N1	0x03

void NS16550_init(NS16550_t com_port, int baud_divisor);
void NS16550_putc(NS16550_t com_port, char c);
char NS16550_getc(NS16550_t com_port);
int NS16550_tstc(NS16550_t com_port);
void NS16550_reinit(NS16550_t com_port, int baud_divisor);

/**
 * ns16550_calc_divisor() - calculate the divisor given clock and baud rate
 *
 * Given the UART input clock and required baudrate, calculate the divisor
 * that should be used.
 *
 * @port:	UART port
 * @clock:	UART input clock speed in Hz
 * @baudrate:	Required baud rate
 * @return baud rate divisor that should be used
 */
int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate);