Research V7 development

Work on file usr/sys/dev/cat.c

Synthesized-from: v7

diff --git a/usr/sys/dev/cat.c b/usr/sys/dev/cat.c
new file mode 100644 (file)
index 0000000..46bd3c1
--- /dev/null
+++ b/usr/sys/dev/cat.c
@@ -0,0 +1,74 @@
+#
+/*
+ */
+
+/*
+ * GP DR11C driver used for C/A/T
+ */
+
+#include "../h/param.h"
+#include "../h/dir.h"
+#include "../h/user.h"
+#include "../h/tty.h"
+
+#define        CATADDR ((struct catdev *)0167770)
+#define        PCAT    (PZERO+9)
+#define        CATHIWAT        100
+#define        CATLOWAT        30
+
+struct {
+       int     catlock;
+       struct  clist   oq;
+} cat;
+
+struct catdev {
+       int     catcsr;
+       int     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((caddr_t)&cat.oq);
+               } else {
+                       if (cat.catlock==0)
+                               CATADDR->catcsr = 0;
+               }
+       }
+}