sam: printer support

diff --git a/Kernel/platform-sam/devlpr.c b/Kernel/platform-sam/devlpr.c
index 65d8c43..a6cc047 100644 (file)
--- a/Kernel/platform-sam/devlpr.c
+++ b/Kernel/platform-sam/devlpr.c
@@ -3,36 +3,66 @@
 #include <kdata.h>
 #include <devlpr.h>
 
-__sfr __at 0x02 lpstat;                /* I/O 2 and 3 */
-__sfr __at 0x03 lpdata;
+__sfr __at 232 lpdata;
+__sfr __at 233 lpstrobe;
+__sfr __at 233 lpbusy;
+__sfr __at 234 lpmode;
 
 int lpr_open(uint8_t minor, uint16_t flag)
 {
-    minor; flag; // shut up compiler
-    return 0;
+       used(flag);
+
+       if (minor) {
+               udata.u_error = ENODEV;
+               return -1;
+       }
+       lpmode = 0;
+       return 0;
 }
 
 int lpr_close(uint8_t minor)
 {
-    minor; // shut up compiler
-    return 0;
+       used(minor);
+       return 0;
 }
 
+/* FIXME: review strobe delay requirement */
+static void nap(void)
+{
+}
+
+static uint8_t iopoll(void)
+{
+       /* Ought to be a core helper for this lot ? */
+       if (need_reschedule())
+               _sched_yield();
+       if (chksigs()) {
+               if (!udata.u_done) {
+                       udata.u_error = EINTR;
+                       udata.u_done = (usize_t) - 1;
+               }
+               return 1;
+       }
+       return 0;
+}
+
+
 int lpr_write(uint8_t minor, uint8_t rawflag, uint8_t flag)
 {
-    int c = udata.u_count;
-    char *p = udata.u_base;
-    minor; rawflag; flag; // shut up compiler
-
-    while(c) {
-        /* Note; on real hardware it might well be necessary to
-           busy wait a bit just to get acceptable performance */
-        while (lpstat != 0xFF) {
-//            if (psleep_flags(&clocktick, flag))
-//                return -1;
-        }
-        /* FIXME: tidy up ugetc and sysio checks globally */
-        lpdata = ugetc(p++);
-    }
-    return (-1);
+       minor;
+       rawflag;
+       flag;
+
+       while (udata.u_done < udata.u_count) {
+               while (lpbusy) {
+                       if (iopoll())
+                               return udata.u_done;
+               }
+               lpdata = ugetc(udata.u_base++);
+               lpstrobe = 1;
+               nap();
+               lpstrobe = 0;
+               udata.u_done++;
+       }
+       return (-1);
 }