staging: ozwpan: Added event logging support

The event logging subsystem allows internal events in the driver to
be logged. This facilitates testing the correct operation of the
driver. This subsystem is optional and can be switched out at
compile time.

Signed-off-by: Chris Kelly <ckelly@ozmodevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 116 insertions, 0 deletions

diff --git a/drivers/staging/ozwpan/ozevent.c b/drivers/staging/ozwpan/ozevent.c
new file mode 100644
index 000000000000..73703d3e96bd
--- /dev/null
+++ b/drivers/staging/ozwpan/ozevent.c
@@ -0,0 +1,116 @@
+/* -----------------------------------------------------------------------------
+ * Copyright (c) 2011 Ozmo Inc
+ * Released under the GNU General Public License Version 2 (GPLv2).
+ * -----------------------------------------------------------------------------
+ */
+#include "ozconfig.h"
+#ifdef WANT_EVENT_TRACE
+#include <linux/jiffies.h>
+#include <linux/uaccess.h>
+#include "oztrace.h"
+#include "ozevent.h"
+/*------------------------------------------------------------------------------
+ */
+unsigned long g_evt_mask = 0xffffffff;
+/*------------------------------------------------------------------------------
+ */
+#define OZ_MAX_EVTS	2048	/* Must be power of 2 */
+DEFINE_SPINLOCK(g_eventlock);
+static int g_evt_in;
+static int g_evt_out;
+static int g_missed_events;
+static struct oz_event g_events[OZ_MAX_EVTS];
+/*------------------------------------------------------------------------------
+ * Context: process
+ */
+void oz_event_init(void)
+{
+	oz_trace("Event tracing initialized\n");
+	g_evt_in = g_evt_out = 0;
+	g_missed_events = 0;
+}
+/*------------------------------------------------------------------------------
+ * Context: process
+ */
+void oz_event_term(void)
+{
+	oz_trace("Event tracing terminated\n");
+}
+/*------------------------------------------------------------------------------
+ * Context: any
+ */
+void oz_event_log2(u8 evt, u8 ctx1, u16 ctx2, void *ctx3, unsigned ctx4)
+{
+	unsigned long irqstate;
+	int ix;
+	spin_lock_irqsave(&g_eventlock, irqstate);
+	ix = (g_evt_in + 1) & (OZ_MAX_EVTS - 1);
+	if (ix != g_evt_out) {
+		struct oz_event *e = &g_events[g_evt_in];
+		e->jiffies = jiffies;
+		e->evt = evt;
+		e->ctx1 = ctx1;
+		e->ctx2 = ctx2;
+		e->ctx3 = ctx3;
+		e->ctx4 = ctx4;
+		g_evt_in = ix;
+	} else {
+		g_missed_events++;
+	}
+	spin_unlock_irqrestore(&g_eventlock, irqstate);
+}
+/*------------------------------------------------------------------------------
+ * Context: process
+ */
+int oz_events_copy(struct oz_evtlist __user *lst)
+{
+	int first;
+	int ix;
+	struct hdr {
+		int count;
+		int missed;
+	} hdr;
+	ix = g_evt_out;
+	hdr.count = g_evt_in - ix;
+	if (hdr.count < 0)
+		hdr.count += OZ_MAX_EVTS;
+	if (hdr.count > OZ_EVT_LIST_SZ)
+		hdr.count = OZ_EVT_LIST_SZ;
+	hdr.missed = g_missed_events;
+	g_missed_events = 0;
+	if (copy_to_user((void __user *)lst, &hdr, sizeof(hdr)))
+		return -EFAULT;
+	first = OZ_MAX_EVTS - ix;
+	if (first > hdr.count)
+		first = hdr.count;
+	if (first) {
+		int sz = first*sizeof(struct oz_event);
+		void __user *p = (void __user *)lst->evts;
+		if (copy_to_user(p, &g_events[ix], sz))
+			return -EFAULT;
+		if (hdr.count > first) {
+			p = (void __user *)&lst->evts[first];
+			sz = (hdr.count-first)*sizeof(struct oz_event);
+			if (copy_to_user(p, g_events, sz))
+				return -EFAULT;
+		}
+	}
+	ix += hdr.count;
+	if (ix >= OZ_MAX_EVTS)
+		ix -= OZ_MAX_EVTS;
+	g_evt_out = ix;
+	return 0;
+}
+/*------------------------------------------------------------------------------
+ * Context: process
+ */
+void oz_events_clear(void)
+{
+	unsigned long irqstate;
+	spin_lock_irqsave(&g_eventlock, irqstate);
+	g_evt_in = g_evt_out = 0;
+	g_missed_events = 0;
+	spin_unlock_irqrestore(&g_eventlock, irqstate);
+}
+#endif /* WANT_EVENT_TRACE */
+