This patch adds a list of v4l2_file_handle structures to every video_device.
It allows using file handle related information in V4L2. The event interface
is one example of such use.
Signed-off-by: Sakari Ailus <sakari.ai...@maxwell.research.nokia.com>
---
drivers/media/video/Makefile | 2 +-
drivers/media/video/v4l2-dev.c | 7 +++-
drivers/media/video/v4l2-fh.c | 95 ++++++++++++++++++++++++++++++++++++++++
include/media/v4l2-dev.h | 4 ++
include/media/v4l2-fh.h | 45 +++++++++++++++++++
5 files changed, 151 insertions(+), 2 deletions(-)
create mode 100644 drivers/media/video/v4l2-fh.c
create mode 100644 include/media/v4l2-fh.h
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index a61e3f3..1947146 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -10,7 +10,7 @@ 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
+videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o
# V4L2 core modules
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 7090699..387a302 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -283,7 +283,8 @@ static int v4l2_open(struct inode *inode, struct file *filp)
/* and increase the device refcount */
video_get(vdev);
mutex_unlock(&videodev_lock);
- if (vdev->fops->open)
+ ret = v4l2_file_handle_add(vdev, filp);
+ if (!ret && vdev->fops->open)
ret = vdev->fops->open(filp);
/* decrease the refcount in case of an error */
@@ -301,6 +302,8 @@ static int v4l2_release(struct inode *inode, struct file
*filp)
if (vdev->fops->release)
vdev->fops->release(filp);
+ v4l2_file_handle_del(vdev, filp);
+
/* decrease the refcount unconditionally since the release()
return value is ignored. */
video_put(vdev);
@@ -421,6 +424,8 @@ static int __video_register_device(struct video_device
*vdev, int type, int nr,
if (!vdev->release)
return -EINVAL;
+ v4l2_file_handle_init(vdev);
+
/* Part 1: check device type */
switch (type) {
case VFL_TYPE_GRABBER:
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
new file mode 100644
index 0000000..52cb3b3
--- /dev/null
+++ b/drivers/media/video/v4l2-fh.c
@@ -0,0 +1,95 @@
+/*
+ * drivers/media/video/v4l2-fh.c
+ *
+ * V4L2 file handles.
+ *
+ * Copyright (C) 2009 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ai...@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 <linux/sched.h>
+#include <linux/vmalloc.h>
+
+static struct v4l2_file_handle *__v4l2_file_handle_get(
+ struct video_device *vdev, struct file *filp)
+{
+ struct v4l2_file_handle *fh;
+
+ list_for_each_entry(fh, &vdev->fh, list) {
+ if (fh->filp == filp)
+ return fh;
+ }
+
+ return NULL;
+}
+
+struct v4l2_file_handle *v4l2_file_handle_get(struct video_device *vdev,
+ struct file *filp)
+{
+ struct v4l2_file_handle *fh;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vdev->fh_lock, flags);
+ fh = __v4l2_file_handle_get(vdev, filp);
+ spin_unlock_irqrestore(&vdev->fh_lock, flags);
+
+ return fh;
+}
+EXPORT_SYMBOL_GPL(v4l2_file_handle_get);
+
+int v4l2_file_handle_add(struct video_device *vdev, struct file *filp)
+{
+ struct v4l2_file_handle *fh;
+ unsigned long flags;
+
+ fh = kmalloc(sizeof(*fh), GFP_KERNEL);
+ if (!fh)
+ return -ENOMEM;
+
+ fh->filp = filp;
+
+ spin_lock_irqsave(&vdev->fh_lock, flags);
+ list_add(&fh->list, &vdev->fh);
+ spin_unlock_irqrestore(&vdev->fh_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_file_handle_add);
+
+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;
+
+ spin_lock_irqsave(&vdev->fh_lock, flags);
+ list_del(&fh->list);
+ spin_unlock_irqrestore(&vdev->fh_lock, flags);
+
+ kfree(fh);
+}
+EXPORT_SYMBOL_GPL(v4l2_file_handle_del);
+
+void v4l2_file_handle_init(struct video_device *vdev)
+{
+ spin_lock_init(&vdev->fh_lock);
+ INIT_LIST_HEAD(&vdev->fh);
+}
+EXPORT_SYMBOL_GPL(v4l2_file_handle_init);
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 2dee938..8eac93d 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -16,6 +16,8 @@
#include <linux/mutex.h>
#include <linux/videodev2.h>
+#include <media/v4l2-fh.h>
+
#define VIDEO_MAJOR 81
#define VFL_TYPE_GRABBER 0
@@ -77,6 +79,8 @@ struct video_device
/* attribute to differentiate multiple indices on one physical device */
int index;
+ spinlock_t fh_lock; /* Lock for file handle list */
+ struct list_head fh; /* File handle list */
int debug; /* Activates debug level*/
/* Video standard vars */
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
new file mode 100644
index 0000000..5c9d08b
--- /dev/null
+++ b/include/media/v4l2-fh.h
@@ -0,0 +1,45 @@
+/*
+ * include/media/v4l2-fh.h
+ *
+ * V4L2 file handle.
+ *
+ * Copyright (C) 2009 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ai...@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_FH_H
+#define V4L2_FH_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+struct v4l2_file_handle {
+ struct list_head list;
+ struct file *filp;
+};
+
+struct video_device;
+
+struct v4l2_file_handle *v4l2_file_handle_get(struct video_device *vdev,
+ struct file *filp);
+int __must_check v4l2_file_handle_add(struct video_device *vdev,
+ struct file *filp);
+void v4l2_file_handle_del(struct video_device *vdev, struct file *filp);
+void v4l2_file_handle_init(struct video_device *vdev);
+
+#endif /* V4L2_EVENT_H */
--
1.5.6.5
--
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