sio.c

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/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
 *	$Id: sio.c,v 1.224.2.5 1999/04/13 18:54:43 jhay Exp $
 */

#include "opt_comconsole.h"
#include "opt_compat.h"
#include "opt_ddb.h"
#include "opt_devfs.h"
#include "opt_sio.h"
#include "sio.h"
#include "pnp.h"

/*
 * Serial driver, based on 386BSD-0.1 com driver.
 * Mostly rewritten to use pseudo-DMA.
 * Works for National Semiconductor NS8250-NS16550AF UARTs.
 * COM driver, based on HP dca driver.
 *
 * Changes for PC-Card integration:
 *	- Added PC-Card driver table and handlers
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/reboot.h>
#include <sys/malloc.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/dkstat.h>
#include <sys/fcntl.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif
#include <sys/timepps.h>

#include <machine/clock.h>
#include <machine/ipl.h>
#ifndef SMP
#include <machine/lock.h>
#endif

#include <i386/isa/isa.h>
#include <i386/isa/isa_device.h>
#include <i386/isa/sioreg.h>
#include <i386/isa/intr_machdep.h>

#ifdef COM_ESP
#include <i386/isa/ic/esp.h>
#endif
#include <i386/isa/ic/ns16550.h>

#include "card.h"
#if NCARD > 0
#include <sys/module.h>
#include <pccard/cardinfo.h>
#include <pccard/slot.h>
#endif

#if NPNP > 0
#include <i386/isa/pnp.h>
#endif

#ifdef SMP
#define disable_intr()	COM_DISABLE_INTR()
#define enable_intr()	COM_ENABLE_INTR()
#endif /* SMP */

#ifndef EXTRA_SIO
#if NPNP > 0
#define EXTRA_SIO MAX_PNP_CARDS
#else
#define EXTRA_SIO 0
#endif
#endif

#define NSIOTOT (NSIO + EXTRA_SIO)

#define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
#define	RS_IBUFSIZE	256

#define	CALLOUT_MASK		0x80
#define	CONTROL_MASK		0x60
#define	CONTROL_INIT_STATE	0x20
#define	CONTROL_LOCK_STATE	0x40
#define	DEV_TO_UNIT(dev)	(MINOR_TO_UNIT(minor(dev)))
#define	MINOR_MAGIC_MASK	(CALLOUT_MASK | CONTROL_MASK)
#define	MINOR_TO_UNIT(mynor)	((mynor) & ~MINOR_MAGIC_MASK)

#ifdef COM_MULTIPORT
/* checks in flags for multiport and which is multiport "master chip"
 * for a given card
 */
#define	COM_ISMULTIPORT(dev)	((dev)->id_flags & 0x01)
#define	COM_MPMASTER(dev)	(((dev)->id_flags >> 8) & 0x0ff)
#define	COM_NOTAST4(dev)	((dev)->id_flags & 0x04)
#endif /* COM_MULTIPORT */

#define	COM_CONSOLE(dev)	((dev)->id_flags & 0x10)
#define	COM_FORCECONSOLE(dev)	((dev)->id_flags & 0x20)
#define	COM_LLCONSOLE(dev)	((dev)->id_flags & 0x40)
#define	COM_LOSESOUTINTS(dev)	((dev)->id_flags & 0x08)
#define	COM_NOFIFO(dev)		((dev)->id_flags & 0x02)
#define COM_ST16650A(dev)	((dev)->id_flags & 0x20000)
#define COM_C_NOPROBE     (0x40000)
#define COM_NOPROBE(dev)  ((dev)->id_flags & COM_C_NOPROBE)
#define COM_C_IIR_TXRDYBUG    (0x80000)
#define COM_IIR_TXRDYBUG(dev) ((dev)->id_flags & COM_C_IIR_TXRDYBUG)
#define	COM_FIFOSIZE(dev)	(((dev)->id_flags & 0xff000000) >> 24)

#define	com_scr		7	/* scratch register for 16450-16550 (R/W) */

/*
 * Input buffer watermarks.
 * The external device is asked to stop sending when the buffer exactly reaches
 * high water, or when the high level requests it.
 * The high level is notified immediately (rather than at a later clock tick)
 * when this watermark is reached.
 * The buffer size is chosen so the watermark should almost never be reached.
 * The low watermark is invisibly 0 since the buffer is always emptied all at
 * once.
 */
#define	RS_IHIGHWATER (3 * RS_IBUFSIZE / 4)

/*
 * com state bits.
 * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
 * than the other bits so that they can be tested as a group without masking
 * off the low bits.
 *
 * The following com and tty flags correspond closely:
 *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
 *				   siostop())
 *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
 *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
 *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
 * TS_FLUSH is not used.
 * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
 * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
 */
#define	CS_BUSY		0x80	/* output in progress */
#define	CS_TTGO		0x40	/* output not stopped by XOFF */
#define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
#define	CS_CHECKMSR	1	/* check of MSR scheduled */
#define	CS_CTS_OFLOW	2	/* use CTS output flow control */
#define	CS_DTR_OFF	0x10	/* DTR held off */
#define	CS_ODONE	4	/* output completed */
#define	CS_RTS_IFLOW	8	/* use RTS input flow control */
#define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */

static	char const * const	error_desc[] = {
#define	CE_OVERRUN			0
	"silo overflow",
#define	CE_INTERRUPT_BUF_OVERFLOW	1
	"interrupt-level buffer overflow",
#define	CE_TTY_BUF_OVERFLOW		2
	"tty-level buffer overflow",
};

#define	CE_NTYPES			3
#define	CE_RECORD(com, errnum)		(++(com)->delta_error_counts[errnum])

/* types.  XXX - should be elsewhere */
typedef u_int	Port_t;		/* hardware port */
typedef u_char	bool_t;		/* boolean */

/* queue of linear buffers */
struct lbq {
	u_char	*l_head;	/* next char to process */
	u_char	*l_tail;	/* one past the last char to process */
	struct lbq *l_next;	/* next in queue */
	bool_t	l_queued;	/* nonzero if queued */
};

/* com device structure */
struct com_s {
	u_int	id_flags;	/* Copy isa device falgas */
	u_char	state;		/* miscellaneous flag bits */
	bool_t  active_out;	/* nonzero if the callout device is open */
	u_char	cfcr_image;	/* copy of value written to CFCR */
#ifdef COM_ESP
	bool_t	esp;		/* is this unit a hayes esp board? */
#endif
	u_char	extra_state;	/* more flag bits, separate for order trick */
	u_char	fifo_image;	/* copy of value written to FIFO */
	bool_t	hasfifo;	/* nonzero for 16550 UARTs */
	bool_t	st16650a;	/* Is a Startech 16650A or RTS/CTS compat */
	bool_t	loses_outints;	/* nonzero if device loses output interrupts */
	u_char	mcr_image;	/* copy of value written to MCR */
#ifdef COM_MULTIPORT
	bool_t	multiport;	/* is this unit part of a multiport device? */
#endif /* COM_MULTIPORT */
	bool_t	no_irq;		/* nonzero if irq is not attached */
	bool_t  gone;		/* hardware disappeared */
	bool_t	poll;		/* nonzero if polling is required */
	bool_t	poll_output;	/* nonzero if polling for output is required */
	int	unit;		/* unit	number */
	int	dtr_wait;	/* time to hold DTR down on close (* 1/hz) */
	u_int	tx_fifo_size;
	u_int	wopeners;	/* # processes waiting for DCD in open() */

	/*
	 * The high level of the driver never reads status registers directly
	 * because there would be too many side effects to handle conveniently.
	 * Instead, it reads copies of the registers stored here by the
	 * interrupt handler.
	 */
	u_char	last_modem_status;	/* last MSR read by intr handler */
	u_char	prev_modem_status;	/* last MSR handled by high level */

	u_char	hotchar;	/* ldisc-specific char to be handled ASAP */
	u_char	*ibuf;		/* start of input buffer */
	u_char	*ibufend;	/* end of input buffer */
	u_char	*ihighwater;	/* threshold in input buffer */
	u_char	*iptr;		/* next free spot in input buffer */

	struct lbq	obufq;	/* head of queue of output buffers */
	struct lbq	obufs[2];	/* output buffers */

	Port_t	data_port;	/* i/o ports */
#ifdef COM_ESP
	Port_t	esp_port;
#endif
	Port_t	int_id_port;
	Port_t	iobase;
	Port_t	modem_ctl_port;
	Port_t	line_status_port;
	Port_t	modem_status_port;
	Port_t	intr_ctl_port;	/* Ports of IIR register */

	struct tty	*tp;	/* cross reference */

	/* Initial state. */
	struct termios	it_in;	/* should be in struct tty */
	struct termios	it_out;

	/* Lock state. */
	struct termios	lt_in;	/* should be in struct tty */
	struct termios	lt_out;

	bool_t	do_timestamp;
	bool_t	do_dcd_timestamp;
	struct timeval	timestamp;
	struct timeval	dcd_timestamp;
	struct	pps_state pps;

	u_long	bytes_in;	/* statistics */
	u_long	bytes_out;
	u_int	delta_error_counts[CE_NTYPES];
	u_long	error_counts[CE_NTYPES];

	/*
	 * Ping-pong input buffers.  The extra factor of 2 in the sizes is
	 * to allow for an error byte for each input byte.
	 */
#define	CE_INPUT_OFFSET		RS_IBUFSIZE
	u_char	ibuf1[2 * RS_IBUFSIZE];
	u_char	ibuf2[2 * RS_IBUFSIZE];

	/*
	 * Data area for output buffers.  Someday we should build the output
	 * buffer queue without copying data.
	 */
	u_char	obuf1[256];
	u_char	obuf2[256];
#ifdef DEVFS
	void	*devfs_token_ttyd;
	void	*devfs_token_ttyl;
	void	*devfs_token_ttyi;
	void	*devfs_token_cuaa;
	void	*devfs_token_cual;
	void	*devfs_token_cuai;
#endif
};

#ifdef COM_ESP
static	int	espattach	__P((struct isa_device *isdp, struct com_s *com,
				     Port_t esp_port));
#endif
static	int	sioattach	__P((struct isa_device *dev));
static	timeout_t siobusycheck;
static	timeout_t siodtrwakeup;
static	void	comhardclose	__P((struct com_s *com));
static	ointhand2_t	siointr;
static	void	siointr1	__P((struct com_s *com));
static	int	commctl		__P((struct com_s *com, int bits, int how));
static	int	comparam	__P((struct tty *tp, struct termios *t));
static	swihand_t siopoll;
static	int	sioprobe	__P((struct isa_device *dev));
static	void	siosettimeout	__P((void));
static	void	comstart	__P((struct tty *tp));
static	timeout_t comwakeup;
static	void	disc_optim	__P((struct tty	*tp, struct termios *t,
				     struct com_s *com));


static char driver_name[] = "sio";

/* table and macro for fast conversion from a unit number to its com struct */
static	struct com_s	*p_com_addr[NSIOTOT];
#define	com_addr(unit)	(p_com_addr[unit])

struct isa_driver	siodriver = {
	sioprobe, sioattach, driver_name
};

static	d_open_t	sioopen;
static	d_close_t	sioclose;
static	d_read_t	sioread;
static	d_write_t	siowrite;
static	d_ioctl_t	sioioctl;
static	d_stop_t	siostop;
static	d_devtotty_t	siodevtotty;

#define	CDEV_MAJOR	28
static	struct cdevsw	sio_cdevsw = {
	sioopen,	sioclose,	sioread,	siowrite,
	sioioctl,	siostop,	noreset,	siodevtotty,
	ttpoll,		nommap,		NULL,		driver_name,
	NULL,		-1,		nodump,		nopsize,
	D_TTY,
};

static	int	comconsole = -1;
static	volatile speed_t	comdefaultrate = CONSPEED;
static	u_int	com_events;	/* input chars + weighted output completions */
static	Port_t	siocniobase;
static	bool_t	sio_registered;
static	int	sio_timeout;
static	int	sio_timeouts_until_log;
static	struct	callout_handle sio_timeout_handle
    = CALLOUT_HANDLE_INITIALIZER(&sio_timeout_handle);
#if 0 /* XXX */
static struct tty	*sio_tty[NSIOTOT];
#else
static struct tty	sio_tty[NSIOTOT];
#endif
static	const int	nsio_tty = NSIOTOT;

static	struct speedtab comspeedtab[] = {
	{ 0,		0 },
	{ 50,		COMBRD(50) },
	{ 75,		COMBRD(75) },
	{ 110,		COMBRD(110) },
	{ 134,		COMBRD(134) },
	{ 150,		COMBRD(150) },
	{ 200,		COMBRD(200) },
	{ 300,		COMBRD(300) },
	{ 600,		COMBRD(600) },
	{ 1200,		COMBRD(1200) },
	{ 1800,		COMBRD(1800) },
	{ 2400,		COMBRD(2400) },
	{ 4800,		COMBRD(4800) },
	{ 9600,		COMBRD(9600) },
	{ 19200,	COMBRD(19200) },
	{ 38400,	COMBRD(38400) },
	{ 57600,	COMBRD(57600) },
	{ 115200,	COMBRD(115200) },
	{ -1,		-1 }
};

#ifdef COM_ESP
/* XXX configure this properly. */
static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
#endif

/*
 * handle sysctl read/write requests for console speed
 * 
 * In addition to setting comdefaultrate for I/O through /dev/console,
 * also set the initial and lock values for the /dev/ttyXX device
 * if there is one associated with the console.  Finally, if the /dev/tty
 * device has already been open, change the speed on the open running port
 * itself.
 */

static int
sysctl_machdep_comdefaultrate SYSCTL_HANDLER_ARGS
{
	int error, s;
	speed_t newspeed;
	struct com_s *com;
	struct tty *tp;

	newspeed = comdefaultrate;

	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
	if (error || !req->newptr)
		return (error);

	comdefaultrate = newspeed;

	if (comconsole < 0)		/* serial console not selected? */
		return (0);

	com = com_addr(comconsole);
	if (!com)
		return (ENXIO);

	/*
	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
	 * (note, the lock rates really are boolean -- if non-zero, disallow
	 *  speed changes)
	 */
	com->it_in.c_ispeed  = com->it_in.c_ospeed =
	com->lt_in.c_ispeed  = com->lt_in.c_ospeed =
	com->it_out.c_ispeed = com->it_out.c_ospeed =
	com->lt_out.c_ispeed = com->lt_out.c_ospeed = comdefaultrate;

	/*
	 * if we're open, change the running rate too
	 */
	tp = com->tp;
	if (tp && (tp->t_state & TS_ISOPEN)) {
		tp->t_termios.c_ispeed =
		tp->t_termios.c_ospeed = comdefaultrate;
		s = spltty();
		error = comparam(tp, &tp->t_termios);
		splx(s);
	}
	return error;
}

SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RW,
	    0, 0, sysctl_machdep_comdefaultrate, "I", "");

#if NCARD > 0
/*
 *	PC-Card (PCMCIA) specific code.
 */
static int	sioinit		__P((struct pccard_devinfo *));
static void	siounload	__P((struct pccard_devinfo *));
static int	card_intr	__P((struct pccard_devinfo *));

PCCARD_MODULE(sio, sioinit, siounload, card_intr, 0, tty_imask);

/*
 *	Initialize the device - called from Slot manager.
 */
int
sioinit(struct pccard_devinfo *devi)
{

	/* validate unit number. */
	if (devi->isahd.id_unit >= (NSIOTOT))
		return(ENODEV);
	/* Make sure it isn't already probed. */
	if (com_addr(devi->isahd.id_unit))
		return(EBUSY);

	/* It's already probed as serial by Upper */
	devi->isahd.id_flags |= COM_C_NOPROBE; 

	/*