update from reeves; eliminates overlaid c-list q; tested with 4.2

[unix-history] / usr / src / sys / kern / tty_tb.c

/*      tty_tb.c        4.9     83/08/13        */

#include "tb.h"
#if NTB > 0

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/ioctl.h"
#include "../h/tty.h"
#include "../h/proc.h"
#include "../h/inode.h"
#include "../h/file.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/uio.h"

/*
* Line discipline for RS232 tablets.
* Supplies binary coordinate data.
*
* MAKE TABLET TYPE AN ioctl TO AVOID HAVING ONE DISCIPLINE PER TABLET TYPE.
*/

#define NTBS            (16)
#define MALLTABCHAR     (8)
#define MTABCHAR        (5)
#define MNTABCHAR       (6)

struct tb {
       short used;
       char cbuf[MALLTABCHAR];
       struct tbpos {
               int     xpos;
               int     ypos;
               short   status;
               short   scount;
       } tbpos;
} tb[NTBS];

/*
* Open as tablet discipline.  Called when discipline changed
* with ioctl, and changes the interpretation of the information
* in the tty structure.
*/
/*ARGSUSED*/
tbopen(dev, tp)
       dev_t dev;
       register struct tty *tp;
{
       register struct tb *tbp;

       if (tp->t_line == TABLDISC || tp->t_line == NTABLDISC)
               return (ENODEV);
       ttywflush(tp);
       for (tbp = tb; tbp < &tb[NTBS]; tbp++)
               if (!tbp->used)
                       break;
       if (tbp >= &tb[NTBS])
               return (EBUSY);
       tbp->used++;
       tp->t_cp = tbp->cbuf;
       tp->t_inbuf = 0;
       tbp->tbpos.xpos = tbp->tbpos.ypos = 0;
       tbp->tbpos.status = tbp->tbpos.scount = 0;
       tp->T_LINEP = (caddr_t) tbp;
       return (0);
}

/*
* Break down... called when discipline changed or from device
* close routine.
*/
tbclose(tp)
       register struct tty *tp;
{
       register int s = spl5();

       tp->t_cp = 0;
       tp->t_inbuf = 0;
       tp->t_rawq.c_cc = 0;            /* clear queues -- paranoid */
       tp->t_canq.c_cc = 0;
       tp->t_line = 0;         /* paranoid: avoid races */
       splx(s);
}

/*
* Read from a tablet line.
* Characters have been buffered in a buffer and
* decoded. The coordinates are now sluffed back to the user.
*/
tbread(tp, uio)
       register struct tty *tp;
       struct uio *uio;
{
       register int i;
       register s;
       struct tbpos *tbpos;

       if ((tp->t_state&TS_CARR_ON)==0)
               return (EIO);
       tbpos = &(((struct tb *) (tp->T_LINEP))->tbpos);
       return (uiomove(tbpos, sizeof *tbpos, UIO_READ, uio));
}

/*
* Low level character input routine.
* Stuff the character in the buffer, and decode the it
* if all the chars are there.
*
* This routine could be expanded in-line in the receiver
* interrupt routine of the dh-11 to make it run as fast as possible.
*/
int     LASTTABC;

tbinput(c, tp)
       register int c;
       register struct tty *tp;
{
       register struct tb *tbp = (struct tb *) tp->T_LINEP;

       if (tp->t_line == TABLDISC) {
               if ((c&0200) || (tp->t_inbuf == MTABCHAR)) {
                       tp->t_cp = tbp->cbuf;
                       tp->t_inbuf = 0;
               }
               *tp->t_cp++ = c&0177;
               if (++tp->t_inbuf == MTABCHAR)
                       tbdecode(tbp->cbuf, &tbp->tbpos);
       } else if (tp->t_line == NTABLDISC) {
               if ((c&0200) || (tp->t_inbuf == MNTABCHAR)) {
                       tp->t_cp = tbp->cbuf;
                       tp->t_inbuf = 0;
               }
               *tp->t_cp++ = c&0177;
               if (++tp->t_inbuf == MNTABCHAR)
                       tbndecode(tbp->cbuf, &tbp->tbpos);
       }
}

/*
* Decode tablet coordinates from ascii to binary.
*      (gtco 6 character format)
*/
tbndecode(cp, tbpos)
       register char *cp;
       register struct tbpos *tbpos;
{

       tbpos->status = *cp>>2; /* this needs to be decoded */
       tbpos->xpos = ((*cp++)&03)<<14;
       tbpos->xpos |= (*cp++)<<7;
       tbpos->xpos |= (*cp++);
       tbpos->ypos = ((*cp++)&03)<<14;
       tbpos->ypos |= (*cp++)<<7;
       tbpos->ypos |= (*cp++);
       tbpos->scount++;
}

/*
* Decode tablet coordinates from ascii to binary.
*      (hitachi 5 character format)
*/
tbdecode(cp, tbpos)
       register char *cp;
       register struct tbpos *tbpos;
{
       register int status;
       register char byte;

       byte = *cp++;
       status = (byte&0100) ? 0100000 : 0;
       byte &= ~0100;
       if (byte > 036)
               status |= 1<<((byte-040)/2);
       tbpos->xpos = (*cp++)<<7;
       tbpos->xpos |= (*cp++);
       if (tbpos->xpos < 256)          /* tablet wraps around at 256 */
               status &= 077777;       /* make it out of proximity */
       tbpos->ypos = (*cp++)<<7;
       tbpos->ypos |= (*cp++);
       tbpos->status  = status;
       tbpos->scount++;
}

/*
* This routine is called whenever a ioctl is about to be performed
* and gets a chance to reject the ioctl.  We reject all teletype
* oriented ioctl's except those which set the discipline, and
* those which get parameters (gtty and get special characters).
*/
/*ARGSUSED*/
tbioctl(tp, cmd, data, flag)
       struct tty *tp;
       caddr_t data;
{

       if ((cmd>>8) != 't')
               return (cmd);
       switch (cmd) {

       case TIOCSETD:
       case TIOCGETD:
       case TIOCGETP:
       case TIOCGETC:
               return (cmd);
       }
       u.u_error = ENOTTY;
       return (0);
}
#endif