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lms.c revision 1.6.2.14
      1       1.1   andrew /*-
      2  1.6.2.11  mycroft  * Copyright (c) 1993 Charles Hannum.
      3       1.1   andrew  * Copyright (c) 1992, 1993 Erik Forsberg.
      4       1.1   andrew  * All rights reserved.
      5       1.1   andrew  *
      6       1.1   andrew  * Redistribution and use in source and binary forms, with or without
      7       1.1   andrew  * modification, are permitted provided that the following conditions
      8       1.1   andrew  * are met:
      9       1.1   andrew  * 1. Redistributions of source code must retain the above copyright
     10       1.1   andrew  *    notice, this list of conditions and the following disclaimer.
     11       1.1   andrew  *
     12       1.1   andrew  * THIS SOFTWARE IS PROVIDED BY ``AS IS'' AND ANY EXPRESS OR IMPLIED
     13       1.1   andrew  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     14       1.1   andrew  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
     15       1.1   andrew  * NO EVENT SHALL I BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     16       1.1   andrew  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     17       1.1   andrew  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     18       1.1   andrew  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     19       1.1   andrew  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     20       1.1   andrew  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     21       1.1   andrew  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     22       1.1   andrew  *
     23  1.6.2.14  mycroft  *	$Id: lms.c,v 1.6.2.14 1993/10/31 16:55:28 mycroft Exp $
     24       1.1   andrew  */
     25       1.1   andrew 
     26  1.6.2.13  mycroft #include <sys/param.h>
     27  1.6.2.13  mycroft #include <sys/kernel.h>
     28  1.6.2.13  mycroft #include <sys/systm.h>
     29  1.6.2.13  mycroft #include <sys/buf.h>
     30  1.6.2.13  mycroft #include <sys/malloc.h>
     31  1.6.2.13  mycroft #include <sys/ioctl.h>
     32  1.6.2.13  mycroft #include <sys/tty.h>
     33  1.6.2.13  mycroft #include <sys/file.h>
     34  1.6.2.13  mycroft #include <sys/select.h>
     35  1.6.2.13  mycroft #include <sys/proc.h>
     36  1.6.2.13  mycroft #include <sys/vnode.h>
     37  1.6.2.13  mycroft #include <sys/device.h>
     38  1.6.2.13  mycroft 
     39  1.6.2.13  mycroft #include <machine/cpu.h>
     40  1.6.2.13  mycroft #include <machine/mouse.h>
     41  1.6.2.13  mycroft #include <machine/pio.h>
     42       1.1   andrew 
     43  1.6.2.13  mycroft #include <i386/isa/isavar.h>
     44  1.6.2.13  mycroft #include <i386/isa/icu.h>
     45       1.1   andrew 
     46   1.6.2.1  mycroft #define LMS_DATA	0       /* Offset for data port, read-only */
     47   1.6.2.1  mycroft #define LMS_SIGN	1       /* Offset for signature port, read-write */
     48   1.6.2.1  mycroft #define LMS_INTR	2       /* Offset for interrupt port, read-only */
     49   1.6.2.1  mycroft #define LMS_CNTRL	2       /* Offset for control port, write-only */
     50   1.6.2.1  mycroft #define LMS_CONFIG	3	/* for configuration port, read-write */
     51   1.6.2.1  mycroft #define	LMS_NPORTS	4
     52   1.6.2.1  mycroft 
     53   1.6.2.1  mycroft #define	LMS_CHUNK	128	/* chunk size for read */
     54   1.6.2.8  mycroft #define	LMS_BSIZE	1020	/* buffer size */
     55   1.6.2.1  mycroft 
     56   1.6.2.1  mycroft struct lms_softc {		/* Driver status information */
     57   1.6.2.5  mycroft 	struct	device sc_dev;
     58   1.6.2.5  mycroft 	struct	isadev sc_id;
     59   1.6.2.5  mycroft 	struct	intrhand sc_ih;
     60   1.6.2.5  mycroft 
     61   1.6.2.8  mycroft 	struct	clist sc_q;
     62   1.6.2.1  mycroft 	struct	selinfo sc_rsel;
     63   1.6.2.1  mycroft 	u_short	sc_iobase;	/* I/O port base */
     64   1.6.2.1  mycroft 	u_char	sc_state;	/* Mouse driver state */
     65   1.6.2.2  mycroft #define LMS_OPEN	0x01	/* Device is open */
     66   1.6.2.2  mycroft #define LMS_ASLP	0x02	/* Waiting for mouse data */
     67   1.6.2.1  mycroft 	u_char	sc_status;	/* Mouse button status */
     68   1.6.2.1  mycroft 	int	sc_x, sc_y;	/* accumulated motion in the X,Y axis */
     69       1.1   andrew };
     70       1.1   andrew 
     71   1.6.2.1  mycroft static int lmsprobe __P((struct device *, struct cfdata *, void *));
     72   1.6.2.1  mycroft static void lmsforceintr __P((void *));
     73   1.6.2.1  mycroft static void lmsattach __P((struct device *, struct device *, void *));
     74   1.6.2.1  mycroft static int lmsintr __P((void *));
     75       1.1   andrew 
     76   1.6.2.1  mycroft struct cfdriver lmscd =
     77  1.6.2.12  mycroft { NULL, "lms", lmsprobe, lmsattach, DV_TTY, sizeof (struct lms_softc) };
     78       1.1   andrew 
     79   1.6.2.8  mycroft #define LMSUNIT(dev)	(minor(dev))
     80       1.1   andrew 
     81   1.6.2.1  mycroft static int
     82   1.6.2.1  mycroft lmsprobe(parent, cf, aux)
     83   1.6.2.1  mycroft 	struct device *parent;
     84   1.6.2.1  mycroft 	struct cfdata *cf;
     85   1.6.2.1  mycroft 	void *aux;
     86       1.1   andrew {
     87   1.6.2.1  mycroft 	struct	isa_attach_args *ia = aux;
     88   1.6.2.1  mycroft 	u_short	iobase = ia->ia_iobase;
     89       1.1   andrew 
     90   1.6.2.6  mycroft 	if (iobase == IOBASEUNK)
     91   1.6.2.6  mycroft 		return 0;
     92   1.6.2.6  mycroft 
     93       1.1   andrew 	/* Configure and check for port present */
     94   1.6.2.1  mycroft 	outb(iobase + LMS_CONFIG, 0x91);
     95   1.6.2.1  mycroft 	delay(10);
     96   1.6.2.1  mycroft 	outb(iobase + LMS_SIGN, 0x0c);
     97   1.6.2.1  mycroft 	delay(10);
     98   1.6.2.1  mycroft 	if (inb(iobase + LMS_SIGN) != 0x0c)
     99   1.6.2.1  mycroft 		return 0;
    100   1.6.2.1  mycroft 	outb(iobase + LMS_SIGN, 0x50);
    101   1.6.2.1  mycroft 	delay(10);
    102   1.6.2.1  mycroft 	if (inb(iobase + LMS_SIGN) != 0x50)
    103   1.6.2.1  mycroft 		return 0;
    104   1.6.2.1  mycroft 
    105  1.6.2.14  mycroft 	/* disable interrupts */
    106  1.6.2.14  mycroft 	outb(iobase + LMS_CNTRL, 0x10);
    107  1.6.2.14  mycroft 
    108   1.6.2.6  mycroft 	if (ia->ia_irq == IRQUNK) {
    109   1.6.2.6  mycroft 		ia->ia_irq = isa_discoverintr(lmsforceintr, aux);
    110   1.6.2.6  mycroft 		if (ia->ia_irq == IRQNONE)
    111   1.6.2.6  mycroft 			return 0;
    112  1.6.2.14  mycroft 		/* disable interrupts */
    113  1.6.2.14  mycroft 		outb(iobase + LMS_CNTRL, 0x10);
    114   1.6.2.6  mycroft 	}
    115   1.6.2.1  mycroft 
    116   1.6.2.1  mycroft 	ia->ia_iosize = LMS_NPORTS;
    117   1.6.2.1  mycroft 	ia->ia_drq = DRQUNK;
    118   1.6.2.1  mycroft 	ia->ia_msize = 0;
    119   1.6.2.1  mycroft 	return 1;
    120       1.1   andrew }
    121       1.1   andrew 
    122   1.6.2.1  mycroft static void
    123   1.6.2.1  mycroft lmsforceintr(aux)
    124   1.6.2.1  mycroft 	void *aux;
    125       1.1   andrew {
    126   1.6.2.1  mycroft 	struct	isa_attach_args *ia = aux;
    127       1.1   andrew 
    128   1.6.2.1  mycroft 	/* enable interrupts; expect to get one in 1/60 second */
    129   1.6.2.1  mycroft 	outb(ia->ia_iobase + LMS_CNTRL, 0);
    130       1.1   andrew }
    131       1.1   andrew 
    132   1.6.2.1  mycroft static void
    133   1.6.2.1  mycroft lmsattach(parent, self, aux)
    134   1.6.2.1  mycroft 	struct device *parent, *self;
    135   1.6.2.1  mycroft 	void *aux;
    136       1.1   andrew {
    137   1.6.2.1  mycroft 	struct	lms_softc *sc = (struct lms_softc *)self;
    138   1.6.2.1  mycroft 	struct	isa_attach_args *ia = aux;
    139   1.6.2.1  mycroft 	u_short	iobase = ia->ia_iobase;
    140   1.6.2.1  mycroft 
    141   1.6.2.1  mycroft 	/* other initialization done by lmsprobe */
    142   1.6.2.1  mycroft 	sc->sc_iobase = iobase;
    143   1.6.2.1  mycroft 	sc->sc_state = 0;
    144       1.1   andrew 
    145   1.6.2.5  mycroft 	printf(": Logitech mouse\n");
    146   1.6.2.6  mycroft 	isa_establish(&sc->sc_id, &sc->sc_dev);
    147   1.6.2.5  mycroft 
    148   1.6.2.6  mycroft 	sc->sc_ih.ih_fun = lmsintr;
    149   1.6.2.6  mycroft 	sc->sc_ih.ih_arg = sc;
    150   1.6.2.6  mycroft 	intr_establish(ia->ia_irq, &sc->sc_ih, DV_TTY);
    151       1.1   andrew }
    152       1.1   andrew 
    153   1.6.2.1  mycroft int
    154   1.6.2.1  mycroft lmsopen(dev, flag)
    155   1.6.2.1  mycroft 	dev_t dev;
    156   1.6.2.1  mycroft 	int flag;
    157       1.1   andrew {
    158   1.6.2.1  mycroft 	int	unit = LMSUNIT(dev);
    159   1.6.2.1  mycroft 	struct	lms_softc *sc;
    160       1.1   andrew 
    161   1.6.2.1  mycroft 	if (unit >= lmscd.cd_ndevs)
    162   1.6.2.1  mycroft 		return ENXIO;
    163   1.6.2.5  mycroft 	sc = lmscd.cd_devs[unit];
    164   1.6.2.1  mycroft 	if (!sc)
    165   1.6.2.1  mycroft 		return ENXIO;
    166   1.6.2.1  mycroft 
    167   1.6.2.2  mycroft 	if (sc->sc_state & LMS_OPEN)
    168   1.6.2.1  mycroft 		return EBUSY;
    169   1.6.2.1  mycroft 
    170   1.6.2.8  mycroft 	if (clalloc(&sc->sc_q, LMS_BSIZE, 0) == -1)
    171   1.6.2.8  mycroft 		return ENOMEM;
    172   1.6.2.8  mycroft 
    173   1.6.2.2  mycroft 	sc->sc_state |= LMS_OPEN;
    174   1.6.2.1  mycroft 	sc->sc_status = 0;
    175   1.6.2.1  mycroft 	sc->sc_x = sc->sc_y = 0;
    176       1.1   andrew 
    177   1.6.2.1  mycroft 	/* enable interrupts */
    178   1.6.2.1  mycroft 	outb(sc->sc_iobase + LMS_CNTRL, 0);
    179       1.1   andrew 
    180   1.6.2.1  mycroft 	return 0;
    181   1.6.2.1  mycroft }
    182       1.1   andrew 
    183   1.6.2.1  mycroft int
    184   1.6.2.1  mycroft lmsclose(dev, flag)
    185   1.6.2.1  mycroft 	dev_t dev;
    186   1.6.2.1  mycroft 	int flag;
    187   1.6.2.1  mycroft {
    188   1.6.2.1  mycroft 	int	unit = LMSUNIT(dev);
    189   1.6.2.5  mycroft 	struct	lms_softc *sc = lmscd.cd_devs[unit];
    190       1.1   andrew 
    191   1.6.2.1  mycroft 	/* disable interrupts */
    192   1.6.2.1  mycroft 	outb(sc->sc_iobase + LMS_CNTRL, 0x10);
    193       1.1   andrew 
    194   1.6.2.2  mycroft 	sc->sc_state &= ~LMS_OPEN;
    195       1.1   andrew 
    196   1.6.2.8  mycroft 	clfree(&sc->sc_q);
    197   1.6.2.8  mycroft 
    198   1.6.2.1  mycroft 	return 0;
    199       1.1   andrew }
    200       1.1   andrew 
    201   1.6.2.1  mycroft int
    202   1.6.2.1  mycroft lmsread(dev, uio, flag)
    203   1.6.2.1  mycroft 	dev_t dev;
    204   1.6.2.1  mycroft 	struct uio *uio;
    205   1.6.2.1  mycroft 	int flag;
    206       1.1   andrew {
    207   1.6.2.1  mycroft 	int	unit = LMSUNIT(dev);
    208   1.6.2.5  mycroft 	struct	lms_softc *sc = lmscd.cd_devs[unit];
    209   1.6.2.1  mycroft 	int	s;
    210   1.6.2.1  mycroft 	int	error;
    211   1.6.2.1  mycroft 	size_t	length;
    212   1.6.2.1  mycroft 	u_char	buffer[LMS_CHUNK];
    213       1.1   andrew 
    214       1.1   andrew 	/* Block until mouse activity occured */
    215       1.1   andrew 
    216       1.1   andrew 	s = spltty();
    217   1.6.2.8  mycroft 	while (sc->sc_q.c_cc == 0) {
    218   1.6.2.8  mycroft 		if (flag & IO_NDELAY) {
    219       1.1   andrew 			splx(s);
    220   1.6.2.1  mycroft 			return EWOULDBLOCK;
    221       1.1   andrew 		}
    222   1.6.2.2  mycroft 		sc->sc_state |= LMS_ASLP;
    223   1.6.2.1  mycroft 		if (error = tsleep((caddr_t)sc, PZERO | PCATCH, "lmsrea", 0)) {
    224   1.6.2.2  mycroft 			sc->sc_state &= ~LMS_ASLP;
    225       1.1   andrew 			splx(s);
    226   1.6.2.1  mycroft 			return error;
    227       1.1   andrew 		}
    228       1.1   andrew 	}
    229  1.6.2.13  mycroft 	splx(s);
    230       1.1   andrew 
    231       1.1   andrew 	/* Transfer as many chunks as possible */
    232       1.1   andrew 
    233   1.6.2.8  mycroft 	while (sc->sc_q.c_cc > 0 && uio->uio_resid > 0) {
    234   1.6.2.8  mycroft 		length = min(sc->sc_q.c_cc, uio->uio_resid);
    235       1.1   andrew 		if (length > sizeof(buffer))
    236       1.1   andrew 			length = sizeof(buffer);
    237       1.1   andrew 
    238   1.6.2.8  mycroft 		/* remove a small chunk from input queue */
    239   1.6.2.8  mycroft 		(void) q_to_b(&sc->sc_q, buffer, length);
    240       1.1   andrew 
    241   1.6.2.8  mycroft 		/* copy data to user process */
    242   1.6.2.1  mycroft 		if (error = uiomove(buffer, length, uio))
    243       1.1   andrew 			break;
    244       1.1   andrew 	}
    245       1.1   andrew 
    246   1.6.2.1  mycroft 	return error;
    247       1.1   andrew }
    248       1.1   andrew 
    249   1.6.2.1  mycroft int
    250   1.6.2.1  mycroft lmsioctl(dev, cmd, addr, flag)
    251   1.6.2.1  mycroft 	dev_t dev;
    252   1.6.2.1  mycroft 	int cmd;
    253   1.6.2.1  mycroft 	caddr_t addr;
    254   1.6.2.1  mycroft 	int flag;
    255       1.1   andrew {
    256   1.6.2.1  mycroft 	int	unit = LMSUNIT(dev);
    257   1.6.2.5  mycroft 	struct	lms_softc *sc = lmscd.cd_devs[unit];
    258   1.6.2.1  mycroft 	struct	mouseinfo info;
    259   1.6.2.1  mycroft 	int	s;
    260   1.6.2.1  mycroft 	int	error;
    261       1.1   andrew 
    262       1.1   andrew 	switch (cmd) {
    263   1.6.2.1  mycroft 	    case MOUSEIOCREAD:
    264       1.1   andrew 		s = spltty();
    265       1.1   andrew 
    266   1.6.2.1  mycroft 		info.status = sc->sc_status;
    267   1.6.2.1  mycroft 		if (sc->sc_x || sc->sc_y)
    268       1.1   andrew 			info.status |= MOVEMENT;
    269       1.1   andrew 
    270   1.6.2.1  mycroft 		if (sc->sc_x > 127)
    271       1.1   andrew 			info.xmotion = 127;
    272   1.6.2.1  mycroft 		else if (sc->sc_x < -127)
    273   1.6.2.1  mycroft 			/* bounding at -127 avoids a bug in XFree86 */
    274       1.3  mycroft 			info.xmotion = -127;
    275       1.1   andrew 		else
    276   1.6.2.1  mycroft 			info.xmotion = sc->sc_x;
    277       1.1   andrew 
    278   1.6.2.1  mycroft 		if (sc->sc_y > 127)
    279       1.1   andrew 			info.ymotion = 127;
    280   1.6.2.1  mycroft 		else if (sc->sc_y < -127)
    281       1.3  mycroft 			info.ymotion = -127;
    282       1.1   andrew 		else
    283   1.6.2.1  mycroft 			info.ymotion = sc->sc_y;
    284       1.1   andrew 
    285   1.6.2.8  mycroft 		/* reset historical information */
    286   1.6.2.1  mycroft 		sc->sc_x = 0;
    287   1.6.2.1  mycroft 		sc->sc_y = 0;
    288   1.6.2.1  mycroft 		sc->sc_status &= ~BUTCHNGMASK;
    289   1.6.2.8  mycroft 		flushq(&sc->sc_q);
    290       1.1   andrew 
    291       1.1   andrew 		splx(s);
    292       1.1   andrew 		error = copyout(&info, addr, sizeof(struct mouseinfo));
    293       1.1   andrew 		break;
    294       1.1   andrew 
    295   1.6.2.1  mycroft 	    default:
    296       1.1   andrew 		error = EINVAL;
    297       1.1   andrew 		break;
    298   1.6.2.1  mycroft 	}
    299       1.1   andrew 
    300   1.6.2.1  mycroft 	return error;
    301       1.1   andrew }
    302       1.1   andrew 
    303   1.6.2.1  mycroft int
    304   1.6.2.1  mycroft lmsintr(arg)
    305   1.6.2.1  mycroft 	void *arg;
    306       1.1   andrew {
    307   1.6.2.1  mycroft 	struct	lms_softc *sc = (struct lms_softc *)arg;
    308   1.6.2.1  mycroft 	u_short	iobase = sc->sc_iobase;
    309   1.6.2.1  mycroft 	u_char	hi, lo, buttons, changed;
    310   1.6.2.1  mycroft 	char	dx, dy;
    311   1.6.2.8  mycroft 	u_char	buffer[5];
    312   1.6.2.1  mycroft 
    313   1.6.2.2  mycroft 	if ((sc->sc_state & LMS_OPEN) == 0)
    314   1.6.2.1  mycroft 		/* interrupts not expected */
    315   1.6.2.1  mycroft 		return 0;
    316   1.6.2.1  mycroft 
    317   1.6.2.1  mycroft 	outb(iobase + LMS_CNTRL, 0xab);
    318   1.6.2.1  mycroft 	hi = inb(iobase + LMS_DATA);
    319   1.6.2.1  mycroft 	outb(iobase + LMS_CNTRL, 0x90);
    320   1.6.2.1  mycroft 	lo = inb(iobase + LMS_DATA);
    321   1.6.2.1  mycroft 	dx = ((hi & 0x0f) << 4) | (lo & 0x0f);
    322   1.6.2.1  mycroft 	/* bounding at -127 avoids a bug in XFree86 */
    323       1.3  mycroft 	dx = (dx == -128) ? -127 : dx;
    324       1.3  mycroft 
    325   1.6.2.1  mycroft 	outb(iobase + LMS_CNTRL, 0xf0);
    326   1.6.2.1  mycroft 	hi = inb(iobase + LMS_DATA);
    327   1.6.2.1  mycroft 	outb(iobase + LMS_CNTRL, 0xd0);
    328   1.6.2.1  mycroft 	lo = inb(iobase + LMS_DATA);
    329   1.6.2.1  mycroft 	dy = ((hi & 0x0f) << 4) | (lo & 0x0f);
    330       1.1   andrew 	dy = (dy == -128) ? 127 : -dy;
    331       1.3  mycroft 
    332   1.6.2.1  mycroft 	outb(iobase + LMS_CNTRL, 0);
    333   1.6.2.1  mycroft 
    334   1.6.2.4  mycroft 	buttons = (~hi >> 5) & 0x07;
    335   1.6.2.4  mycroft 	changed = ((buttons ^ sc->sc_status) & 0x07) << 3;
    336   1.6.2.4  mycroft 	sc->sc_status = buttons | (sc->sc_status & ~BUTSTATMASK) | changed;
    337   1.6.2.1  mycroft 
    338   1.6.2.4  mycroft 	if (dx || dy || changed) {
    339   1.6.2.8  mycroft 		/* update accumulated movements */
    340   1.6.2.1  mycroft 		sc->sc_x += dx;
    341   1.6.2.1  mycroft 		sc->sc_y += dy;
    342   1.6.2.1  mycroft 
    343   1.6.2.8  mycroft 		buffer[0] = 0x80 | (buttons ^ BUTSTATMASK);
    344   1.6.2.8  mycroft 		buffer[1] = dx;
    345   1.6.2.8  mycroft 		buffer[2] = dy;
    346   1.6.2.8  mycroft 		buffer[3] = buffer[4] = 0;
    347   1.6.2.8  mycroft 		(void) b_to_q(buffer, sizeof buffer, &sc->sc_q);
    348       1.1   andrew 
    349   1.6.2.2  mycroft 		if (sc->sc_state & LMS_ASLP) {
    350   1.6.2.2  mycroft 			sc->sc_state &= ~LMS_ASLP;
    351       1.5   andrew 			wakeup((caddr_t)sc);
    352       1.1   andrew 		}
    353   1.6.2.1  mycroft 		selwakeup(&sc->sc_rsel);
    354       1.5   andrew 	}
    355   1.6.2.1  mycroft 
    356   1.6.2.1  mycroft 	return 1;
    357       1.1   andrew }
    358       1.1   andrew 
    359   1.6.2.1  mycroft int
    360   1.6.2.1  mycroft lmsselect(dev, rw, p)
    361   1.6.2.1  mycroft 	dev_t dev;
    362   1.6.2.1  mycroft 	int rw;
    363   1.6.2.1  mycroft 	struct proc *p;
    364       1.1   andrew {
    365   1.6.2.1  mycroft 	int	unit = LMSUNIT(dev);
    366   1.6.2.5  mycroft 	struct	lms_softc *sc = lmscd.cd_devs[unit];
    367   1.6.2.1  mycroft 	int	s;
    368   1.6.2.1  mycroft 	int	ret;
    369       1.1   andrew 
    370       1.1   andrew 	if (rw == FWRITE)
    371   1.6.2.1  mycroft 		return 0;
    372       1.1   andrew 
    373       1.1   andrew 	s = spltty();
    374   1.6.2.8  mycroft 	if (sc->sc_q.c_cc)
    375       1.1   andrew 		ret = 1;
    376       1.1   andrew 	else {
    377   1.6.2.1  mycroft 		selrecord(p, &sc->sc_rsel);
    378       1.1   andrew 		ret = 0;
    379       1.1   andrew 	}
    380       1.1   andrew 	splx(s);
    381       1.1   andrew 
    382   1.6.2.1  mycroft 	return ret;
    383       1.1   andrew }
    384