staging: dgnc: add dgnc digi driver

This patch adds the DGNC driver. This is a TTY Serial Port
Driver for the Digi International Neo and Classic PCI based product
line by Digi International <http://www.digi.com>.

This driver isn't hooked up to the build system because it doesn't
build, it merely adds the driver written by Digi to the kernel tree so
that it can be cleaned up and fixed up properly over time.

Cc: Mark Hounschell <markh@compro.net>
Signed-off-by: Lidza Louina <lidza.louina@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 187 insertions, 0 deletions

diff --git a/drivers/staging/dgnc/dgnc_trace.c b/drivers/staging/dgnc/dgnc_trace.c
new file mode 100644
index 00000000000..ea710e56579
--- /dev/null
+++ b/drivers/staging/dgnc/dgnc_trace.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright 2003 Digi International (www.digi.com)
+ *	Scott H Kilau <Scott_Kilau at digi dot com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
+ * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ *	NOTE TO LINUX KERNEL HACKERS:  DO NOT REFORMAT THIS CODE! 
+ *
+ *	This is shared code between Digi's CVS archive and the
+ *	Linux Kernel sources.
+ *	Changing the source just for reformatting needlessly breaks
+ *	our CVS diff history.
+ *
+ *	Send any bug fixes/changes to:  Eng.Linux at digi dot com. 
+ *	Thank you. 
+ *
+ */
+
+/* $Id: dgnc_trace.c,v 1.1.1.1 2009/05/20 12:19:19 markh Exp $ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/sched.h>	/* For jiffies, task states */
+#include <linux/interrupt.h>	/* For tasklet and interrupt structs/defines */
+#include <linux/vmalloc.h>
+
+#include "dgnc_driver.h"
+
+#define TRC_TO_CONSOLE 1
+
+/* file level globals */
+static char *dgnc_trcbuf;		/* the ringbuffer */
+
+#if defined(TRC_TO_KMEM)
+static int dgnc_trcbufi = 0;		/* index of the tilde at the end of */
+#endif
+
+#if defined(TRC_TO_KMEM)
+static DEFINE_SPINLOCK(dgnc_tracef_lock);
+#endif
+
+
+#if 0
+
+#if !defined(TRC_TO_KMEM) && !defined(TRC_TO_CONSOLE)
+
+void dgnc_tracef(const char *fmt, ...)
+{
+	return;
+}
+
+#else /* !defined(TRC_TO_KMEM) && !defined(TRC_TO_CONSOLE) */
+
+void dgnc_tracef(const char *fmt, ...)
+{
+	va_list	         ap;
+	char  	         buf[TRC_MAXMSG+1];
+	size_t		 lenbuf;
+	int		 i;
+	static int	 failed = FALSE;
+# if defined(TRC_TO_KMEM)
+	unsigned long	 flags;
+#endif
+
+	if(failed)
+		return;
+# if defined(TRC_TO_KMEM)
+	DGNC_LOCK(dgnc_tracef_lock, flags);
+#endif
+
+	/* Format buf using fmt and arguments contained in ap. */
+	va_start(ap, fmt);
+	i = vsprintf(buf, fmt,  ap);
+	va_end(ap);
+	lenbuf = strlen(buf);
+
+# if defined(TRC_TO_KMEM)
+	{
+		static int	 initd=0;
+
+		/*
+		 * Now, in addition to (or instead of) printing this stuff out
+		 * (which is a buffered operation), also tuck it away into a
+		 * corner of memory which can be examined post-crash in kdb.
+		 */
+		if (!initd) {
+			dgnc_trcbuf = (char *) vmalloc(dgnc_trcbuf_size);
+			if(!dgnc_trcbuf) {
+				failed = TRUE;
+				printk("dgnc: tracing init failed!\n");
+				return;
+			}
+
+			memset(dgnc_trcbuf, '\0',  dgnc_trcbuf_size);
+			dgnc_trcbufi = 0;
+			initd++;
+
+			printk("dgnc: tracing enabled - " TRC_DTRC 
+				" 0x%lx 0x%x\n",
+				(unsigned long)dgnc_trcbuf, 
+				dgnc_trcbuf_size);
+		}
+
+#  if defined(TRC_ON_OVERFLOW_WRAP_AROUND)
+		/*
+		 * This is the less CPU-intensive way to do things.  We simply
+		 * wrap around before we fall off the end of the buffer.  A 
+		 * tilde (~) demarcates the current end of the trace.
+		 *
+		 * This method should be used if you are concerned about race
+		 * conditions as it is less likely to affect the timing of
+		 * things.
+		 */
+
+		if (dgnc_trcbufi + lenbuf >= dgnc_trcbuf_size) {
+			/* We are wrapping, so wipe out the last tilde. */
+			dgnc_trcbuf[dgnc_trcbufi] = '\0';
+			/* put the new string at the beginning of the buffer */
+			dgnc_trcbufi = 0;
+		}
+
+		strcpy(&dgnc_trcbuf[dgnc_trcbufi], buf);	
+		dgnc_trcbufi += lenbuf;
+		dgnc_trcbuf[dgnc_trcbufi] = '~';
+
+#  elif defined(TRC_ON_OVERFLOW_SHIFT_BUFFER)
+		/*
+		 * This is the more CPU-intensive way to do things.  If we
+		 * venture into the last 1/8 of the buffer, we shift the 
+		 * last 7/8 of the buffer forward, wiping out the first 1/8.
+		 * Advantage: No wrap-around, only truncation from the
+		 * beginning.
+		 *
+		 * This method should not be used if you are concerned about
+		 * timing changes affecting the behaviour of the driver (ie,
+		 * race conditions).
+		 */
+		strcpy(&dgnc_trcbuf[dgnc_trcbufi], buf);
+		dgnc_trcbufi += lenbuf;
+		dgnc_trcbuf[dgnc_trcbufi] = '~';
+		dgnc_trcbuf[dgnc_trcbufi+1] = '\0';
+
+		/* If we're near the end of the trace buffer... */
+		if (dgnc_trcbufi > (dgnc_trcbuf_size/8)*7) {
+			/* Wipe out the first eighth to make some more room. */
+			strcpy(dgnc_trcbuf, &dgnc_trcbuf[dgnc_trcbuf_size/8]);
+			dgnc_trcbufi = strlen(dgnc_trcbuf)-1;
+			/* Plop overflow message at the top of the buffer. */
+			bcopy(TRC_OVERFLOW, dgnc_trcbuf, strlen(TRC_OVERFLOW));
+		}
+#  else
+#   error "TRC_ON_OVERFLOW_WRAP_AROUND or TRC_ON_OVERFLOW_SHIFT_BUFFER?"
+#  endif
+	}
+	DGNC_UNLOCK(dgnc_tracef_lock, flags);
+
+# endif /* defined(TRC_TO_KMEM) */
+}
+
+#endif /* !defined(TRC_TO_KMEM) && !defined(TRC_TO_CONSOLE) */
+
+#endif
+
+
+/*
+ * dgnc_tracer_free()
+ *
+ *
+ */
+void dgnc_tracer_free(void)
+{
+	if(dgnc_trcbuf)
+		vfree(dgnc_trcbuf);
+}