mdc.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)mdc.c	4.3      (ULTRIX)        9/10/90";
#endif	lint

/************************************************************************
 *									*
 *			Copyright (c) 1990 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any	other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or	reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************
 *
 * mdc.c
 *
 * Mipsmate DC7085 SLU console driver -the real thing!!!!!
 *
 * Modification history
 *
 *
 *  August 22, 1990     Paul Grist
 *      Changed initilazation of console baud rate to use "baud0", it
 *      was left "baud1" from some early prom debug, hence was broke.
 *
 *  July 14, 1990	Kuo-Hsiung Hsieh
 *	Asserted Speed Select (SS) modem control signal in open routine.
 *	Deasserted SS when process exits.  As requested by PTT test.
 *
 *  July 5, 1990	Kuo-Hsiung Hsieh
 *      Fixed data corrupted problem due to setting break condition
 *      on a transmission line.  On DC type of chip, a specific delay
 *      period has to be imposed on the transmission line if the next
 *      thing to transmit is a break condition.  Data could be corrupted
 *      even though TRDY bit may say it is ready to send the next
 * 	character.
 *
 *  June 4, 1990	Kuo-Hsiung Hsieh
 *	Fixed duplicated assertion of break.  It is caused by reading
 *	the transmit data register which is the modem status register.
 *
 *  May 10, 1990	Kuo-Hsiung Hsieh
 *	Fixed linenum typo which caused system hung and added modem stuff.
 *
 *  March 23, 1990	Tim Burke
 *
 *	Created file. Contents based on dc7085.c file.  Due to time constraints
 *	a separate copy of this driver is being developed instead of modifying
 *	the original source to accomodate all three device types.  The main
 *	changes from the dc7085 sources is to remove all references to graphic
 *	capabilities.  This driver can accomodate up to 3 DC7085 chips while
 *	the original driver could only have 1 such chip.  
 *
 *	Extensive cleanups of the original dc7085.c driver were also done.
 *	These cleanups include using #define constants, overhaul of the buad
 *	rate representation scheme.  Use consistent variable terminology,
 *	specifically unit means dc number, linenum is the particular line of
 *	a dc and minor_num is the device minor number.
 */

#include "../machine/pte.h"
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/ioctl.h"
#include "../h/tty.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/map.h"
#include "../h/buf.h"
#include "../h/vm.h"
#include "../h/conf.h"
#include "../h/file.h"
#include "../h/uio.h"
#include "../h/kernel.h"
#include "../h/devio.h"
#include "../../machine/common/cpuconf.h"
#include "../h/exec.h"
#include "../h/kmalloc.h"
#include "../h/sys_tpath.h"
#include "../io/uba/ubavar.h"	/* auto-config headers */

#include "../machine/cpu.h"
#include "../machine/mips/mdcreg.h"

/*
 * Declare the data structures used to represent the terminal attributes.
 */
struct	tty mdc_tty[NDC * NDCLINE]; /* Allocate 1 tty structure per line*/
u_char	mdcmodem[NDC];	   	   /* keeps track of modem state 	*/
u_short mdcscan_previous[NDC];	   /* Used to detect modem transitions  */
int 	mdcmodem_active;	   /* Determines scan rate		*/
int 	console_baud;		   /* Specifies console baud rate	*/
int	mdcdefaultCAR[NDC];	   /* Default status of modem/nomodem   */
int	mdcsoftCAR[NDC];	   /* Present status of modem/nomodem   */
int	mdc_cnt;	   	   /* The number of configured lines	*/
u_char  mdc_brk[NDC];
extern  int nMDC;                  /* Configuration - # of DC chips     */
struct	timeval mdctimestamp[NDC]; /* Timer for modem control		*/
int	mdc_attach_called = 0;	   /* Attach routine has been called    */

int	mdcprobe(), mdcattach(), mdcrint(), mdc_unit_init();
int	mdc_dsr_check(), mdc_tty_drop(), mdc_cd_drop(); 
int	mdcputc(), mdcgetc();
void	mdcsetbreak();

u_short mdcstd[] = { 0 };
struct uba_device *mdcinfo[1];

/*
 * Unibus device driver definition.  These routines are used at boot time by
 * the configuration program.
 */
struct	uba_driver mdcdriver = { 
	mdcprobe, 			/* probe routine		   */
	0, 				/* slave routine		   */
	mdcattach, 			/* attach routine		   */
	0, 				/* ud_dgo routine		   */
	mdcstd, 			/* device csr address		   */
	"mdc", 				/* device name			   */
	mdcinfo 			/* backpointers to ubdinit structs */
					/* I guess the rest are just 0's   */
					/* name of a controller		   */
					/* backpointers to ubminit structs */
					/* want exclusive use of bdp's	   */
    };

int	mdcstart(), mdcxint(), mdcbaudrate();
int	ttrstrt();

#define MODEM_LINE	2		/* Modem control only on line 2     */
#define NOMODEM_UNIT	2		/* DC #2 does not have full modem   */
#define LINEMASK	0x03		/* line unit mask, each DC has 4 lines*/
#define LINEBITS	2		/* The linemask occupies 2 bits     */


/*
 * Baud Rate Support
 *
 * When the baud rate on the right is specified, the line parameter register
 * is setup with the appropriate bits as specified in the left column.
 */
#define BAUD_UNSUPPORTED 0	/* Device does not provide this baud rate */
#define BAUD_SUPPORTED   1	/* Device does provide this baud rate     */

/*
 * If the BAUD38 bit of the System Control and Status Register is set the
 * chip can do 38400 baud in which case EXTB would be supported.  This bit
 * applies to all 4 lines such that it is not possible to simultaneously do
 * 19200 and 38400.  To keep things simple, only provide support for 19.2.
 * The third column is the minimum delay value for setting a break
 * condition.  If we set a break condition without delaying this minimum
 * interval, we might corrupt character which is still in the shift
 * register.  The delay values are calculated based on the equation:
 * 12 (bits/char) * 256 (hz) / baudrate + 2 (safety factor).

 */
struct baud_support mdc_speeds[] = {
     	{0,			BAUD_UNSUPPORTED,	0},	/* B0    */
	{DC_B50,		BAUD_SUPPORTED,		78},	/* B50   */
	{DC_B75,		BAUD_SUPPORTED,		42},	/* B75   */
	{DC_B110,		BAUD_SUPPORTED,		30},	/* B110  */
	{DC_B134_5,		BAUD_SUPPORTED,		25},	/* B134  */
	{DC_B150,		BAUD_SUPPORTED,		22},	/* B150  */
	{0,			BAUD_UNSUPPORTED,	0},	/* B200  */
	{DC_B300,		BAUD_SUPPORTED,		12},	/* B300  */
	{DC_B600,		BAUD_SUPPORTED,		7},	/* B600  */
	{DC_B1200,		BAUD_SUPPORTED,		5},	/* B1200 */
	{DC_B1800,		BAUD_SUPPORTED,		4},	/* B1800 */
	{DC_B2400,		BAUD_SUPPORTED,		3},	/* B2400 */
	{DC_B4800,		BAUD_SUPPORTED,		2},	/* B4800 */
	{DC_B9600,		BAUD_SUPPORTED,		2},	/* B9600 */
	{DC_B19200,		BAUD_SUPPORTED,		2},	/* EXTA  */
	{0,			BAUD_UNSUPPORTED,	0}, 	/* EXTB  */
   };

extern int pmcons_init();
extern int prom_getenv();
extern int cpu;

#ifdef DEBUG
int mdcdebug = 0;

/*
 * Print out the modem leads for this DC unit.
 */
#define PRINT_SIGNALS(dcaddr) { cprintf("Modem signals: "); \
	if (dcaddr->dcmsr & DC_DSR) cprintf(" DSR "); \
	if (dcaddr->dcmsr & DC_CTS) cprintf(" CTS "); \
	if (dcaddr->dcmsr & DC_CD) cprintf(" CD "); \
	cprintf("\n"); } 
#endif DEBUG


/*
 * Probe to see if the device is alive.  Since this is a bounded configuration
 * there must be a DC chip present for the console.  The intialization is done
 * through dc_cons_init out of startup().
 */
mdcprobe(reg)
int reg;
{
	return(1);
}

/*
 * Initialize the device and setup initial values of relevant variables.
 */
mdcattach()
{
    register int unit;
    extern mdcscan();

    /*
     * If the option card is in place this routine may end up being called
     * more than once.  Use mdc_attach_called to insure that the body of this
     * routine is only executed once.
     */
    if (mdc_attach_called == 0) {
	mdc_attach_called = 1;
	/*
	 * Setup per-DC registers and software status.
	 */
	mdc_cnt = 0;
	if (nMDC <= 0) {
		panic("mdcattach: no units configured.\n");
	}
	if (nMDC > MAX_NDC) {
		nMDC = MAX_NDC;
		cprintf("Too many DC chips configured: nMDC = %d\n",nMDC);
	}
	for (unit = 0; unit < nMDC; unit++) {
		mdc_brk[unit] = 0;
		mdc_unit_init(unit);
		mdc_cnt += NDCLINE;
	}
	/*
 	 * Initialize the scanner process.  Since the chip does not 
	 * interrupt on modem transitions it is necessary to have a scanner
	 * thread that occasionally checks the modem leads and looks for
	 * changes.  Start up this to examine the modem leads once per second.
	 */
 	mdcmodem_active = 0;
	timeout(mdcscan, (caddr_t)0, hz);
    }
}

/*
 * Initalizes the DC registers and associated software attributes.
 * Called on a per unit basis from attach().
 */
mdc_unit_init(unit)
	register int unit;
{
	register volatile struct mdz_reg *dcaddr;

#	ifdef DEBUG
	if (mdcdebug)
		cprintf("mdc_unit_init: unit = %d.\n",unit);
#	endif DEBUG
	if (unit > MAX_NDC) {		/* paranoia */
		return;
	}
	dcaddr = mdz_regs[unit];
	/*
	 * Note that the dcsoftCAR and dcdefaultCAR do not look at the flags
	 * field of the config file.  This may need to be fixed up.
	 */
	mdcsoftCAR[unit] = 0xf;		/* Set lines to direct connect     */
	mdcdefaultCAR[unit] = 0xf;	/* Default lines to direct connect */
	mdcscan_previous[unit] = 0;	/* Initial modem status		   */
	/*
	 * DC0 and DC1 allow modem control on line 2.  Initialize these leads
	 * to clear the modem control signals.
	 */
	if (unit != NOMODEM_UNIT) {
		dcaddr->dctcr &= ~(DC_RDTR | DC_RRTS | DC_RSS);
	}
}
/*
 * Called early from startup.  The purpose of this routine is to setup the
 * console line to enable output so the startup messages can be displayed.
 */
mdc_cons_init()
{
	register int linenum = CONSOLE_LINE;
	register volatile struct mdz_reg *dcaddr = mdz_regs[CONSOLE_UNIT];
	register int prom_baud;

	/*
	 * The console will default to 9600 baud.  This can be changed via
	 * the baud environment variable.  Read in the console baud rate
	 * for later use.  This presently only supports a selected number of
	 * baud rates.
	 */
	prom_baud = atoi(prom_getenv("baud0"));
	switch (prom_baud) {
		case 75:	console_baud = B75; 	break;
		case 110:	console_baud = B110; 	break;
		case 150:	console_baud = B150; 	break;
		case 300:	console_baud = B300; 	break;
		case 600:	console_baud = B600; 	break;
		case 1200:	console_baud = B1200; 	break;
		case 2400:	console_baud = B2400; 	break;
		case 4800:	console_baud = B4800; 	break;
		case 9600:	console_baud = B9600; 	break;
		default:	console_baud = B9600;
	}

	dcaddr->dclpr = linenum | mdc_speeds[console_baud].baud_param 
			| BITS8 | DC_RE;
}

/*
 * Open line and set default parameters.  If this is a modem line wait for
 * the appropriate leads to be asserted.
 */
mdcopen(dev, flag)
	dev_t dev;
{
	register volatile struct mdz_reg *dcaddr;
	register struct tty *tp;
	register int unit;
	register int linenum;
	register int minor_num;
	int inuse;  /*hold state of inuse bit while blocked waiting for carr*/

	minor_num = minor(dev);
	unit = minor_num >> LINEBITS;
	dcaddr = mdz_regs[unit];
	linenum = minor_num & LINEMASK;
	if (minor_num >= mdc_cnt) {
		return (ENXIO);
	}
	tp = &mdc_tty[minor_num];
	if (tp->t_state&TS_XCLUDE && u.u_uid != 0) {
		return (EBUSY);
	}

	while (tp->t_state&TS_CLOSING) { /* let DTR stay down for awhile */
		sleep((caddr_t)&tp->t_rawq, TTIPRI);
	}
	tp->t_addr = (caddr_t)tp;
	tp->t_oproc = mdcstart;
	tp->t_baudrate = mdcbaudrate;

	tty_def_open(tp, dev, flag, (mdcsoftCAR[unit]&(1<<(linenum))));

	/*
	 * If the line is not presently open setup the default terminal
	 * attributes.
	 */
	if ((tp->t_state & TS_ISOPEN) == 0) {
	    /*
	     * Prevent spurious startups by making the 500ms timer
	     * initially high.
	     */
	    /* Tim  - Should this only be set if opening modem line? */
	    mdcmodem[unit] = MODEM_DSR_START;
	    /*
	     * Specify console terminal attributes.  Do not allow modem control 
	     * on the console.  Setup <NL> to <CR> <LF> mapping.
	     */
	    if ((unit == CONSOLE_UNIT) && (linenum == CONSOLE_LINE)) {
		tp->t_cflag |= CLOCAL;
		tp->t_flags = ANYP|ECHO|CRMOD;
		tp->t_iflag |= ICRNL;
		tp->t_oflag |= ONLCR;
	    }
	}
	mdcparam(minor_num);		/* enables interrupts */
	(void) spltty();


	/*
	 * No modem control provided for lines with softCAR set.
	 * Modem control provided only for line 2.
	 */
#	ifdef DEBUG
	if (mdcdebug)
		cprintf("mdcopen: unit = %d, linenum = %d\n",unit, linenum);
#	endif DEBUG
	/*
	 * Modem control is only provided on line 2 of DC0 and DC1.  All other
	 * lines are restricted to be direct connect.  For this reason set
	 * CLOCAL as a sanity check.
	 */
	if ((unit == NOMODEM_UNIT) || (linenum != MODEM_LINE)) {
		tp->t_cflag |= CLOCAL;
	}
	if (tp->t_cflag & CLOCAL) {
		/*
		 * This is a local connection - ignore carrier
		 * receive enable interrupts enabled above via dcparam()
		 */
		tp->t_state |= TS_CARR_ON;		/* dcscan sets */
		if (linenum == MODEM_LINE) {
			dcaddr->dctcr |= (DC_RDTR | DC_RRTS | DC_RSS);
		}
		/*
		 * Set state bit to tell tty.c not to assign this line as the
		 * controlling terminal for the process which opens this line.
		 */
		if ((flag & O_NOCTTY) && (u.u_procp->p_progenv == A_POSIX))
			tp->t_state |= TS_ONOCTTY;
		(void) spl0();
		return ((*linesw[tp->t_line].l_open)(dev, tp));
	}
	/*
	 *  this is a modem line
	 */
	/* receive enable interrupts enabled above via dcparam() */

	if (linenum == MODEM_LINE) {
		dcaddr->dctcr |= (DC_RDTR | DC_RRTS | DC_RSS);
	}

	/*
	 * After DSR first comes up we must wait for the other signals
	 * before commencing transmission.
         */
#ifdef DEBUG
	if (mdcdebug) {
		cprintf("open flag : %x\n", flag);
		if (flag & (O_NDELAY|O_NONBLOCK)) 
			cprintf("flag & (O_NDELAY|O_NONBLOCK)\n");
	}
#endif DEBUG
	if ((flag & (O_NDELAY|O_NONBLOCK)) == 0) {
		/*
		 * Delay before examining other signals if DSR is being followed
		 * otherwise proceed directly to dc_dsr_check to look for
		 * carrier detect and clear to send.
		 */
#ifdef DEBUG
		if (mdcdebug) {
			cprintf("mdcopen: ");
			PRINT_SIGNALS(dcaddr);
		}
#endif DEBUG
		if (dcaddr->dcmsr & DC_DSR) {
			mdcmodem[unit] |= (MODEM_DSR_START|MODEM_DSR);
			tp->t_dev = dev; /* need it for timeouts */
			    /*
			     * Give CD and CTS 30 sec. to 
			     * come up.  Start transmission
			     * immediately, no longer need
			     * 500ms delay.
			     */
			    timeout(mdc_dsr_check, tp, hz*30);
			    mdc_dsr_check(tp);
		}
	}
#	ifdef DEBUG
	if (mdcdebug)
		cprintf("mdcopen:  linenum=%d, state=0x%x, tp=0x%x\n", linenum,
			tp->t_state, tp);
#	endif DEBUG
	if (flag & (O_NDELAY|O_NONBLOCK))
		tp->t_state |= TS_ONDELAY;
	else
		while ((tp->t_state & TS_CARR_ON) == 0) {
			tp->t_state |= TS_WOPEN;
			inuse = tp->t_state&TS_INUSE;
#ifdef DEBUG
			if (mdcdebug) {
				cprintf("mdc_open: going to sleep\n");
			}
#endif DEBUG
			sleep((caddr_t)&tp->t_rawq, TTIPRI);
			/*
			 * See if we were awoken by a false call to the modem
			 * line by a non-modem.
			 */
			if (mdcmodem[unit]&MODEM_BADCALL){
				(void) spl0();
				return(EWOULDBLOCK);
			}
			/* if we opened "block if in use"  and
			 *  the terminal was not inuse at that time
			 *  but is became "in use" while we were
			 *  waiting for carrier then return
			 */
			if ((flag & O_BLKINUSE) && (inuse==0) &&
				(tp->t_state&TS_INUSE)) {
					(void) spl0();
					return(EALREADY);
			}
		}
	/*
	 * Set state bit to tell tty.c not to assign this line as the
	 * controlling terminal for the process which opens this line.
	 */
	if ((flag & O_NOCTTY) && (u.u_procp->p_progenv == A_POSIX))
		tp->t_state |= TS_ONOCTTY;
	(void) spl0();