3 files changed, 297 insertions, 2 deletions

diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index c84175c5526..c96b2b1e2fd 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -10,7 +10,8 @@ stkwebcam-objs	:=	stk-webcam.o stk-sensor.o
 
 omap2cam-objs	:=	omap24xxcam.o omap24xxcam-dma.o
 
-videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o
+videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
+			v4l2-event.o
 
 # V4L2 core modules
 
diff --git a/drivers/media/video/v4l2-event.c b/drivers/media/video/v4l2-event.c
new file mode 100644
index 00000000000..170e40f56cf
--- /dev/null
+++ b/drivers/media/video/v4l2-event.c
@@ -0,0 +1,290 @@
+/*
+ * v4l2-event.c
+ *
+ * V4L2 events.
+ *
+ * Copyright (C) 2009--2010 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+int v4l2_event_init(struct v4l2_fh *fh)
+{
+	fh->events = kzalloc(sizeof(*fh->events), GFP_KERNEL);
+	if (fh->events == NULL)
+		return -ENOMEM;
+
+	init_waitqueue_head(&fh->events->wait);
+
+	INIT_LIST_HEAD(&fh->events->free);
+	INIT_LIST_HEAD(&fh->events->available);
+	INIT_LIST_HEAD(&fh->events->subscribed);
+
+	fh->events->sequence = -1;
+
+	return 0;
+}
+
+int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
+{
+	struct v4l2_events *events = fh->events;
+	unsigned long flags;
+
+	if (!events) {
+		WARN_ON(1);
+		return -ENOMEM;
+	}
+
+	while (events->nallocated < n) {
+		struct v4l2_kevent *kev;
+
+		kev = kzalloc(sizeof(*kev), GFP_KERNEL);
+		if (kev == NULL)
+			return -ENOMEM;
+
+		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+		list_add_tail(&kev->list, &events->free);
+		events->nallocated++;
+		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_alloc);
+
+#define list_kfree(list, type, member)				\
+	while (!list_empty(list)) {				\
+		type *hi;					\
+		hi = list_first_entry(list, type, member);	\
+		list_del(&hi->member);				\
+		kfree(hi);					\
+	}
+
+void v4l2_event_free(struct v4l2_fh *fh)
+{
+	struct v4l2_events *events = fh->events;
+
+	if (!events)
+		return;
+
+	list_kfree(&events->free, struct v4l2_kevent, list);
+	list_kfree(&events->available, struct v4l2_kevent, list);
+	list_kfree(&events->subscribed, struct v4l2_subscribed_event, list);
+
+	kfree(events);
+	fh->events = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_free);
+
+static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
+{
+	struct v4l2_events *events = fh->events;
+	struct v4l2_kevent *kev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+
+	if (list_empty(&events->available)) {
+		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+		return -ENOENT;
+	}
+
+	WARN_ON(events->navailable == 0);
+
+	kev = list_first_entry(&events->available, struct v4l2_kevent, list);
+	list_move(&kev->list, &events->free);
+	events->navailable--;
+
+	kev->event.pending = events->navailable;
+	*event = kev->event;
+
+	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+	return 0;
+}
+
+int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
+		       int nonblocking)
+{
+	struct v4l2_events *events = fh->events;
+	int ret;
+
+	if (nonblocking)
+		return __v4l2_event_dequeue(fh, event);
+
+	do {
+		ret = wait_event_interruptible(events->wait,
+					       events->navailable != 0);
+		if (ret < 0)
+			return ret;
+
+		ret = __v4l2_event_dequeue(fh, event);
+	} while (ret == -ENOENT);
+
+	return ret;
+}
+
+/* Caller must hold fh->event->lock! */
+static struct v4l2_subscribed_event *v4l2_event_subscribed(
+	struct v4l2_fh *fh, u32 type)
+{
+	struct v4l2_events *events = fh->events;
+	struct v4l2_subscribed_event *sev;
+
+	WARN_ON(!spin_is_locked(&fh->vdev->fh_lock));
+
+	list_for_each_entry(sev, &events->subscribed, list) {
+		if (sev->type == type)
+			return sev;
+	}
+
+	return NULL;
+}
+
+void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
+{
+	struct v4l2_fh *fh;
+	unsigned long flags;
+	struct timespec timestamp;
+
+	ktime_get_ts(&timestamp);
+
+	spin_lock_irqsave(&vdev->fh_lock, flags);
+
+	list_for_each_entry(fh, &vdev->fh_list, list) {
+		struct v4l2_events *events = fh->events;
+		struct v4l2_kevent *kev;
+
+		/* Are we subscribed? */
+		if (!v4l2_event_subscribed(fh, ev->type))
+			continue;
+
+		/* Increase event sequence number on fh. */
+		events->sequence++;
+
+		/* Do we have any free events? */
+		if (list_empty(&events->free))
+			continue;
+
+		/* Take one and fill it. */
+		kev = list_first_entry(&events->free, struct v4l2_kevent, list);
+		kev->event.type = ev->type;
+		kev->event.u = ev->u;
+		kev->event.timestamp = timestamp;
+		kev->event.sequence = events->sequence;
+		list_move_tail(&kev->list, &events->available);
+
+		events->navailable++;
+
+		wake_up_all(&events->wait);
+	}
+
+	spin_unlock_irqrestore(&vdev->fh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_queue);
+
+int v4l2_event_pending(struct v4l2_fh *fh)
+{
+	return fh->events->navailable;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_pending);
+
+int v4l2_event_subscribe(struct v4l2_fh *fh,
+			 struct v4l2_event_subscription *sub)
+{
+	struct v4l2_events *events = fh->events;
+	struct v4l2_subscribed_event *sev;
+	unsigned long flags;
+
+	if (fh->events == NULL) {
+		WARN_ON(1);
+		return -ENOMEM;
+	}
+
+	sev = kmalloc(sizeof(*sev), GFP_KERNEL);
+	if (!sev)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+
+	if (v4l2_event_subscribed(fh, sub->type) == NULL) {
+		INIT_LIST_HEAD(&sev->list);
+		sev->type = sub->type;
+
+		list_add(&sev->list, &events->subscribed);
+		sev = NULL;
+	}
+
+	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+	kfree(sev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
+
+static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
+{
+	struct v4l2_events *events = fh->events;
+	struct v4l2_subscribed_event *sev;
+	unsigned long flags;
+
+	do {
+		sev = NULL;
+
+		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+		if (!list_empty(&events->subscribed)) {
+			sev = list_first_entry(&events->subscribed,
+				       struct v4l2_subscribed_event, list);
+			list_del(&sev->list);
+		}
+		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+		kfree(sev);
+	} while (sev);
+}
+
+int v4l2_event_unsubscribe(struct v4l2_fh *fh,
+			   struct v4l2_event_subscription *sub)
+{
+	struct v4l2_subscribed_event *sev;
+	unsigned long flags;
+
+	if (sub->type == V4L2_EVENT_ALL) {
+		v4l2_event_unsubscribe_all(fh);
+		return 0;
+	}
+
+	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+
+	sev = v4l2_event_subscribed(fh, sub->type);
+	if (sev != NULL)
+		list_del(&sev->list);
+
+	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+	kfree(sev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
index 93ea0af5fac..aab2fb639ef 100644
--- a/drivers/media/video/v4l2-fh.c
+++ b/drivers/media/video/v4l2-fh.c
@@ -25,6 +25,8 @@
 #include <linux/bitops.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
 
 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 {
@@ -32,7 +34,7 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 	INIT_LIST_HEAD(&fh->list);
 	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
 
-	return 0;
+	return v4l2_event_init(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_init);
 
@@ -62,5 +64,7 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
 		return;
 
 	fh->vdev = NULL;
+
+	v4l2_event_free(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_exit);