提交 1babcb46 编写于 作者: S Sakari Ailus 提交者: Mauro Carvalho Chehab

V4L/DVB: V4L: File handles

This patch adds a list of v4l2_fh structures to every video_device.
It allows using file handle related information in V4L2. The event interface
is one example of such use.

The use of v4l2_fh is not mandatory for drivers.
Signed-off-by: NSakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
上级 96d8eab5
......@@ -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
......
......@@ -421,6 +421,10 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
if (!vdev->release)
return -EINVAL;
/* v4l2_fh support */
spin_lock_init(&vdev->fh_lock);
INIT_LIST_HEAD(&vdev->fh_list);
/* Part 1: check device type */
switch (type) {
case VFL_TYPE_GRABBER:
......
/*
* v4l2-fh.c
*
* V4L2 file handles.
*
* 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 <linux/bitops.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
{
fh->vdev = vdev;
INIT_LIST_HEAD(&fh->list);
set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fh_init);
void v4l2_fh_add(struct v4l2_fh *fh)
{
unsigned long flags;
spin_lock_irqsave(&fh->vdev->fh_lock, flags);
list_add(&fh->list, &fh->vdev->fh_list);
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_fh_add);
void v4l2_fh_del(struct v4l2_fh *fh)
{
unsigned long flags;
spin_lock_irqsave(&fh->vdev->fh_lock, flags);
list_del_init(&fh->list);
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_fh_del);
void v4l2_fh_exit(struct v4l2_fh *fh)
{
if (fh->vdev == NULL)
return;
fh->vdev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_fh_exit);
......@@ -32,6 +32,7 @@ struct v4l2_device;
Drivers can clear this flag if they want to block all future
device access. It is cleared by video_unregister_device. */
#define V4L2_FL_REGISTERED (0)
#define V4L2_FL_USES_V4L2_FH (1)
struct v4l2_file_operations {
struct module *owner;
......@@ -77,6 +78,10 @@ struct video_device
/* attribute to differentiate multiple indices on one physical device */
int index;
/* V4L2 file handles */
spinlock_t fh_lock; /* Lock for all v4l2_fhs */
struct list_head fh_list; /* List of struct v4l2_fh */
int debug; /* Activates debug level*/
/* Video standard vars */
......
/*
* v4l2-fh.h
*
* V4L2 file handle. Store per file handle data for the V4L2
* framework. Using file handles is optional for the drivers.
*
* 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
*/
#ifndef V4L2_FH_H
#define V4L2_FH_H
#include <linux/list.h>
struct video_device;
struct v4l2_fh {
struct list_head list;
struct video_device *vdev;
};
/*
* Initialise the file handle. Parts of the V4L2 framework using the
* file handles should be initialised in this function. Must be called
* from driver's v4l2_file_operations->open() handler if the driver
* uses v4l2_fh.
*/
int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
/*
* Add the fh to the list of file handles on a video_device. The file
* handle must be initialised first.
*/
void v4l2_fh_add(struct v4l2_fh *fh);
/*
* Remove file handle from the list of file handles. Must be called in
* v4l2_file_operations->release() handler if the driver uses v4l2_fh.
*/
void v4l2_fh_del(struct v4l2_fh *fh);
/*
* Release resources related to a file handle. Parts of the V4L2
* framework using the v4l2_fh must release their resources here, too.
* Must be called in v4l2_file_operations->release() handler if the
* driver uses v4l2_fh.
*/
void v4l2_fh_exit(struct v4l2_fh *fh);
#endif /* V4L2_EVENT_H */
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