drivers/tty/serial/68328serial.h

/* 68328serial.h: Definitions for the mc68328 serial driver.
 *
 * Copyright (C) 1995       David S. Miller    <davem@caip.rutgers.edu>
 * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
 * Copyright (C) 1998, 1999 D. Jeff Dionne     <jeff@uclinux.org>
 * Copyright (C) 1999       Vladimir Gurevich  <vgurevic@cisco.com>
 *
 * VZ Support/Fixes             Evan Stawnyczy <e@lineo.ca>
 */

#ifndef _MC683XX_SERIAL_H
#define _MC683XX_SERIAL_H


struct serial_struct {
	int	type;
	int	line;
	int	port;
	int	irq;
	int	flags;
	int	xmit_fifo_size;
	int	custom_divisor;
	int	baud_base;
	unsigned short	close_delay;
	char	reserved_char[2];
	int	hub6;  /* FIXME: We don't have AT&T Hub6 boards! */
	unsigned short	closing_wait; /* time to wait before closing */
	unsigned short	closing_wait2; /* no longer used... */
	int	reserved[4];
};

/*
 * For the close wait times, 0 means wait forever for serial port to
 * flush its output.  65535 means don't wait at all.
 */
#define S_CLOSING_WAIT_INF	0
#define S_CLOSING_WAIT_NONE	65535

/*
 * Definitions for S_struct (and serial_struct) flags field
 */
#define S_HUP_NOTIFY 0x0001 /* Notify getty on hangups and closes 
				   on the callout port */
#define S_FOURPORT  0x0002	/* Set OU1, OUT2 per AST Fourport settings */
#define S_SAK	0x0004	/* Secure Attention Key (Orange book) */
#define S_SPLIT_TERMIOS 0x0008 /* Separate termios for dialin/callout */

#define S_SPD_MASK	0x0030
#define S_SPD_HI	0x0010	/* Use 56000 instead of 38400 bps */

#define S_SPD_VHI	0x0020  /* Use 115200 instead of 38400 bps */
#define S_SPD_CUST	0x0030  /* Use user-specified divisor */

#define S_SKIP_TEST	0x0040 /* Skip UART test during autoconfiguration */
#define S_AUTO_IRQ  0x0080 /* Do automatic IRQ during autoconfiguration */
#define S_SESSION_LOCKOUT 0x0100 /* Lock out cua opens based on session */
#define S_PGRP_LOCKOUT    0x0200 /* Lock out cua opens based on pgrp */
#define S_CALLOUT_NOHUP   0x0400 /* Don't do hangups for cua device */

#define S_FLAGS	0x0FFF	/* Possible legal S flags */
#define S_USR_MASK 0x0430	/* Legal flags that non-privileged
				 * users can set or reset */

/* Internal flags used only by kernel/chr_drv/serial.c */
#define S_INITIALIZED	0x80000000 /* Serial port was initialized */
#define S_CALLOUT_ACTIVE	0x40000000 /* Call out device is active */
#define S_NORMAL_ACTIVE	0x20000000 /* Normal device is active */
#define S_BOOT_AUTOCONF	0x10000000 /* Autoconfigure port on bootup */
#define S_CLOSING		0x08000000 /* Serial port is closing */
#define S_CTS_FLOW		0x04000000 /* Do CTS flow control */
#define S_CHECK_CD		0x02000000 /* i.e., CLOCAL */

/* Software state per channel */

#ifdef __KERNEL__

/*
 * I believe this is the optimal setting that reduces the number of interrupts.
 * At high speeds the output might become a little "bursted" (use USTCNT_TXHE
 * if that bothers you), but in most cases it will not, since we try to 
 * transmit characters every time rs_interrupt is called. Thus, quite often
 * you'll see that a receive interrupt occures before the transmit one.
 *                                  -- Vladimir Gurevich
 */
#define USTCNT_TX_INTR_MASK (USTCNT_TXEE)

/*
 * 68328 and 68EZ328 UARTS are a little bit different. EZ328 has special
 * "Old data interrupt" which occures whenever the data stay in the FIFO
 * longer than 30 bits time. This allows us to use FIFO without compromising
 * latency. '328 does not have this feature and without the real  328-based
 * board I would assume that RXRE is the safest setting.
 *
 * For EZ328 I use RXHE (Half empty) interrupt to reduce the number of
 * interrupts. RXFE (receive queue full) causes the system to lose data
 * at least at 115200 baud
 *
 * If your board is busy doing other stuff, you might consider to use
 * RXRE (data ready intrrupt) instead.
 *
 * The other option is to make these INTR masks run-time configurable, so
 * that people can dynamically adapt them according to the current usage.
 *                                  -- Vladimir Gurevich
 */

/* (es) */
#if defined(CONFIG_M68EZ328) || defined(CONFIG_M68VZ328)
#define USTCNT_RX_INTR_MASK (USTCNT_RXHE | USTCNT_ODEN)
#elif defined(CONFIG_M68328)
#define USTCNT_RX_INTR_MASK (USTCNT_RXRE)
#else
#error Please, define the Rx interrupt events for your CPU
#endif
/* (/es) */

/*
 * This is our internal structure for each serial port's state.
 * 
 * Many fields are paralleled by the structure used by the serial_struct
 * structure.
 *
 * For definitions of the flags field, see tty.h
 */

struct m68k_serial {
	char soft_carrier;  /* Use soft carrier on this channel */
	char break_abort;   /* Is serial console in, so process brk/abrt */
	char is_cons;       /* Is this our console. */

	/* We need to know the current clock divisor
	 * to read the bps rate the chip has currently
	 * loaded.
	 */
	unsigned char clk_divisor;  /* May be 1, 16, 32, or 64 */
	int baud;
	int			magic;
	int			baud_base;
	int			port;
	int			irq;
	int			flags; 		/* defined in tty.h */
	int			type; 		/* UART type */
	struct tty_struct 	*tty;
	int			read_status_mask;
	int			ignore_status_mask;
	int			timeout;
	int			xmit_fifo_size;
	int			custom_divisor;
	int			x_char;	/* xon/xoff character */
	int			close_delay;
	unsigned short		closing_wait;
	unsigned short		closing_wait2;
	unsigned long		event;
	unsigned long		last_active;
	int			line;
	int			count;	    /* # of fd on device */
	int			blocked_open; /* # of blocked opens */
	unsigned char 		*xmit_buf;
	int			xmit_head;
	int			xmit_tail;
	int			xmit_cnt;
	wait_queue_head_t	open_wait;
	wait_queue_head_t	close_wait;
};


#define SERIAL_MAGIC 0x5301

/*
 * The size of the serial xmit buffer is 1 page, or 4096 bytes
 */
#define SERIAL_XMIT_SIZE 4096

/*
 * Events are used to schedule things to happen at timer-interrupt
 * time, instead of at rs interrupt time.
 */
#define RS_EVENT_WRITE_WAKEUP	0

/* 
 * Define the number of ports supported and their irqs.
 */
#define NR_PORTS 1
#define UART_IRQ_DEFNS {UART_IRQ_NUM}

#endif /* __KERNEL__ */
#endif /* !(_MC683XX_SERIAL_H) */