diff mbox

[RFC,4/4] V4L: Events: Add backend

Message ID 1260879591-14376-4-git-send-email-sakari.ailus@maxwell.research.nokia.com (mailing list archive)
State RFC
Headers show

Commit Message

Sakari Ailus Dec. 15, 2009, 12:19 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 1947146..dd6a853 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 0000000..91c3acc
--- /dev/null
+++ b/drivers/media/video/v4l2-event.c
@@ -0,0 +1,254 @@ 
+/*
+ * drivers/media/video/v4l2-event.c
+ *
+ * V4L2 events.
+ *
+ * Copyright (C) 2009 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-event.h>
+
+#include <linux/sched.h>
+
+static struct kmem_cache *event_kmem;
+
+static void v4l2_event_kmem_ctor(void *ptr)
+{
+	struct _v4l2_event *ev = ptr;
+
+	INIT_LIST_HEAD(&ev->list);
+}
+
+int v4l2_event_init(struct v4l2_events *events)
+{
+	if (!event_kmem)
+		event_kmem = kmem_cache_create("event_kmem",
+					       sizeof(struct _v4l2_event), 0,
+					       SLAB_HWCACHE_ALIGN,
+					       &v4l2_event_kmem_ctor);
+
+	if (!event_kmem)
+		return -ENOMEM;
+
+	init_waitqueue_head(&events->wait);
+	spin_lock_init(&events->lock);
+
+	INIT_LIST_HEAD(&events->available);
+	INIT_LIST_HEAD(&events->subscribed);
+
+	return 0;
+};
+EXPORT_SYMBOL_GPL(v4l2_event_init);
+
+void v4l2_event_exit(struct v4l2_events *events)
+{
+	while (!list_empty(&events->available)) {
+		struct _v4l2_event *ev;
+
+		ev = list_entry(events->available.next,
+				struct _v4l2_event, list);
+
+		list_del(&ev->list);
+
+		kmem_cache_free(event_kmem, ev);
+	}
+
+	while (!list_empty(&events->subscribed)) {
+		struct v4l2_subscribed_event *sub;
+
+		sub = list_entry(events->subscribed.next,
+				struct v4l2_subscribed_event, list);
+
+		list_del(&sub->list);
+
+		kfree(sub);
+	}
+}
+EXPORT_SYMBOL_GPL(v4l2_event_exit);
+
+int v4l2_event_dequeue(struct v4l2_events *events, struct v4l2_event *event)
+{
+	struct _v4l2_event *ev;
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&events->lock, flags);
+
+	if (list_empty(&events->available)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	ev = list_first_entry(&events->available, struct _v4l2_event, list);
+	list_del(&ev->list);
+
+	ev->event.count = !list_empty(&events->available);
+
+	memcpy(event, &ev->event, sizeof(ev->event));
+
+	kmem_cache_free(event_kmem, ev);
+
+out:
+
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_dequeue);
+
+static struct _v4l2_event *v4l2_event_queue_get(struct v4l2_events *events)
+{
+	return kmem_cache_alloc(event_kmem, GFP_KERNEL | GFP_ATOMIC);
+}
+
+static void v4l2_event_queue_put(struct v4l2_events *events,
+				 struct _v4l2_event *ev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&events->lock, flags);
+
+	list_add(&ev->list, &events->available);
+
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	wake_up_all(&events->wait);
+}
+
+static struct v4l2_subscribed_event *__v4l2_event_subscribed(
+	struct v4l2_events *events, u32 type)
+{
+	struct v4l2_subscribed_event *ev;
+
+	list_for_each_entry(ev, &events->subscribed, list) {
+		if (ev->type == type)
+			return ev;
+	}
+
+	return NULL;
+}
+
+struct v4l2_subscribed_event *v4l2_event_subscribed(
+	struct v4l2_events *events, u32 type)
+{
+	struct v4l2_subscribed_event *ev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&events->lock, flags);
+
+	ev = __v4l2_event_subscribed(events, type);
+
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	return ev;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_subscribed);
+
+void v4l2_event_queue(struct video_device *vdev, struct v4l2_event *ev)
+{
+	struct v4l2_file_handle *fh;
+	unsigned long flags;
+
+	spin_lock_irqsave(&vdev->fh_lock, flags);
+
+	list_for_each_entry(fh, &vdev->fh, list) {
+		struct _v4l2_event *_ev;
+
+		if (!v4l2_event_subscribed(&fh->events, ev->type))
+			continue;
+
+		_ev = v4l2_event_queue_get(&fh->events);
+		if (!_ev)
+			continue;
+
+		_ev->event = *ev;
+		v4l2_event_queue_put(&fh->events, _ev);
+
+		printk(KERN_ALERT "deliver to some fh\n");
+	}
+
+	spin_unlock_irqrestore(&vdev->fh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_queue);
+
+int v4l2_event_pending(struct v4l2_events *events)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&events->lock, flags);
+	ret = list_empty(&events->available);
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_pending);
+
+int v4l2_event_subscribe(struct v4l2_events *events,
+			 struct v4l2_event_subscription *sub)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct v4l2_subscribed_event *ev;
+
+	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+	if (!ev)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&events->lock, flags);
+
+	if (__v4l2_event_subscribed(events, sub->type) != NULL) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	INIT_LIST_HEAD(&ev->list);
+	ev->type = sub->type;
+
+	list_add(&ev->list, &events->subscribed);
+
+out:
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	if (ret)
+		kfree(ev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
+
+int v4l2_event_unsubscribe(struct v4l2_events *events,
+			   struct v4l2_event_subscription *sub)
+{
+	struct v4l2_subscribed_event *ev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&events->lock, flags);
+
+	ev = __v4l2_event_subscribed(events, sub->type);
+
+	if (ev != NULL)
+		list_del(&ev->list);
+
+	spin_unlock_irqrestore(&events->lock, flags);
+
+	return ev == NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
index 52cb3b3..a8d4318 100644
--- a/drivers/media/video/v4l2-fh.c
+++ b/drivers/media/video/v4l2-fh.c
@@ -59,6 +59,7 @@  int v4l2_file_handle_add(struct video_device *vdev, struct file *filp)
 {
 	struct v4l2_file_handle *fh;
 	unsigned long flags;
+	int ret;
 
 	fh = kmalloc(sizeof(*fh), GFP_KERNEL);
 	if (!fh)
@@ -66,6 +67,12 @@  int v4l2_file_handle_add(struct video_device *vdev, struct file *filp)
 
 	fh->filp = filp;
 
+	ret = v4l2_event_init(&fh->events);
+	if (ret) {
+		kfree(fh);
+		return ret;
+	}
+
 	spin_lock_irqsave(&vdev->fh_lock, flags);
 	list_add(&fh->list, &vdev->fh);
 	spin_unlock_irqrestore(&vdev->fh_lock, flags);
@@ -79,6 +86,8 @@  void v4l2_file_handle_del(struct video_device *vdev, struct file *filp)
 	struct v4l2_file_handle *fh = v4l2_file_handle_get(vdev, filp);
 	unsigned long flags;
 
+	v4l2_event_exit(&fh->events);
+
 	spin_lock_irqsave(&vdev->fh_lock, flags);
 	list_del(&fh->list);
 	spin_unlock_irqrestore(&vdev->fh_lock, flags);
diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
new file mode 100644
index 0000000..6984fea
--- /dev/null
+++ b/include/media/v4l2-event.h
@@ -0,0 +1,73 @@ 
+/*
+ * include/media/v4l2-event.h
+ *
+ * V4L2 events.
+ *
+ * Copyright (C) 2009 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
+ */
+
+#ifndef V4L2_EVENT_H
+#define V4L2_EVENT_H
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#include <linux/videodev2.h>
+
+#define V4L2_MAX_EVENTS		1024 /* Ought to be enough for everyone. */
+
+struct video_device;
+
+struct _v4l2_event {
+	struct list_head	list;
+	struct v4l2_event	event;
+};
+
+struct v4l2_events {
+	spinlock_t		lock; /* Protect everything here. */
+	struct list_head	available;
+	wait_queue_head_t	wait;
+	struct list_head	subscribed; /* Subscribed events. */
+};
+
+struct v4l2_subscribed_event {
+	struct list_head	list;
+	u32			type;
+};
+
+int v4l2_event_init(struct v4l2_events *events);
+void v4l2_event_exit(struct v4l2_events *events);
+
+int v4l2_event_dequeue(struct v4l2_events *events, struct v4l2_event *event);
+
+struct v4l2_subscribed_event *v4l2_event_subscribed(struct v4l2_events *sub,
+						    u32 type);
+
+void v4l2_event_queue(struct video_device *vdev, struct v4l2_event *ev);
+int v4l2_event_pending(struct v4l2_events *events);
+
+int v4l2_event_subscribe(struct v4l2_events *sub,
+			 struct v4l2_event_subscription *s);
+int v4l2_event_unsubscribe(struct v4l2_events *sub,
+			   struct v4l2_event_subscription *s);
+void v4l2_event_sub_init(struct v4l2_events *sub);
+void v4l2_event_sub_exit(struct v4l2_events *sub);
+
+#endif /* V4L2_EVENT_H */
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
index 5c9d08b..6e92014 100644
--- a/include/media/v4l2-fh.h
+++ b/include/media/v4l2-fh.h
@@ -28,9 +28,12 @@ 
 #include <linux/types.h>
 #include <linux/list.h>
 
+#include <media/v4l2-event.h>
+
 struct v4l2_file_handle {
 	struct list_head	list;
 	struct file		*filp;
+	struct v4l2_events	events;	/* events, pending and subscribed */
 };
 
 struct video_device;