Bell 32V development

[unix-history] / usr / src / sys / dev / cat.c

#
/*
*/

/*
* GP DR11C driver used for C/A/T
*/

#include "../h/param.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/tty.h"
#include "../h/uba.h"

#define CATADDR ((struct catdev *)(UBA0_DEV+0167770))
#define PCAT    (PZERO+9)
#define CATHIWAT        100
#define CATLOWAT        30

struct {
       int     catlock;
       struct  clist   oq;
} cat;

struct catdev {
       short   catcsr;
       short   catbuf;
};

ctopen(dev)
{
       if (cat.catlock==0) {
               cat.catlock++;
               CATADDR->catcsr |= IENABLE;
       } else
               u.u_error = ENXIO;
}

ctclose()
{
       cat.catlock = 0;
       catintr();
}

ctwrite(dev)
{
       register c;
       extern lbolt;

       while ((c=cpass()) >= 0) {
               spl5();
               while (cat.oq.c_cc > CATHIWAT)
                       sleep((caddr_t)&cat.oq, PCAT);
               while (putc(c, &cat.oq) < 0)
                       sleep((caddr_t)&lbolt, PCAT);
               catintr();
               spl0();
       }
}

catintr()
{
       register int c;

       if (CATADDR->catcsr&DONE) {
               if ((c = getc(&cat.oq)) >= 0) {
                       CATADDR->catbuf = c;
                       if (cat.oq.c_cc==0 || cat.oq.c_cc==CATLOWAT)
                               wakeup(&cat.oq);
               } else {
                       if (cat.catlock==0)
                               CATADDR->catcsr = 0;
               }
       }
}