[v4,1/7] V4L: File handles
Commit Message
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.
Video device drivers should use the v4l2_fh pointer as their
file->private_data.
Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
---
drivers/media/video/Makefile | 3 +-
drivers/media/video/v4l2-dev.c | 2 +
drivers/media/video/v4l2-fh.c | 65 ++++++++++++++++++++++++++++++++++++++++
include/media/v4l2-dev.h | 6 ++++
include/media/v4l2-fh.h | 47 +++++++++++++++++++++++++++++
5 files changed, 122 insertions(+), 1 deletions(-)
create mode 100644 drivers/media/video/v4l2-fh.c
create mode 100644 include/media/v4l2-fh.h
Comments
On Wednesday 10 February 2010 15:58:03 Sakari Ailus wrote:
> 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.
>
> Video device drivers should use the v4l2_fh pointer as their
> file->private_data.
See small review comment below.
Regards,
Hans
>
> Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
> ---
> drivers/media/video/Makefile | 3 +-
> drivers/media/video/v4l2-dev.c | 2 +
> drivers/media/video/v4l2-fh.c | 65 ++++++++++++++++++++++++++++++++++++++++
> include/media/v4l2-dev.h | 6 ++++
> include/media/v4l2-fh.h | 47 +++++++++++++++++++++++++++++
> 5 files changed, 122 insertions(+), 1 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 6e75647..b888ad1 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-subdev.o
> +videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-subdev.o \
> + v4l2-fh.o
>
> # V4L2 core modules
>
> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
> index 13a899d..c24c832 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -423,6 +423,8 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
> if (!vdev->release)
> return -EINVAL;
>
> + v4l2_fhs_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..3c1cea2
> --- /dev/null
> +++ b/drivers/media/video/v4l2-fh.c
> @@ -0,0 +1,65 @@
> +/*
> + * drivers/media/video/v4l2-fh.c
> + *
> + * V4L2 file handles.
> + *
> + * 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-fh.h>
> +
> +void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
> +{
> + fh->vdev = vdev;
> +}
> +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(&fh->list);
> + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(v4l2_fh_del);
> +
> +void v4l2_fh_exit(struct v4l2_fh *fh)
> +{
> + BUG_ON(fh->vdev == NULL);
> + fh->vdev = NULL;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_fh_exit);
> +
> +void v4l2_fhs_init(struct video_device *vdev)
> +{
> + spin_lock_init(&vdev->fh_lock);
> + INIT_LIST_HEAD(&vdev->fh_list);
> +}
Move the contents of this function to __video_register_device. I do not see
any particular need to have a separate function here.
> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> index 26d4e79..ee3a0c9 100644
> --- a/include/media/v4l2-dev.h
> +++ b/include/media/v4l2-dev.h
> @@ -18,6 +18,8 @@
>
> #include <media/media-entity.h>
>
> +#include <media/v4l2-fh.h>
> +
> #define VIDEO_MAJOR 81
>
> #define VFL_TYPE_GRABBER 0
> @@ -82,6 +84,10 @@ 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 */
> diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
> new file mode 100644
> index 0000000..2e88031
> --- /dev/null
> +++ b/include/media/v4l2-fh.h
> @@ -0,0 +1,47 @@
> +/*
> + * include/media/v4l2-fh.h
> + *
> + * V4L2 file handle.
> + *
> + * 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_FH_H
> +#define V4L2_FH_H
> +
> +#include <linux/types.h>
> +#include <linux/list.h>
> +
> +#include <asm/atomic.h>
> +
> +struct video_device;
> +
> +struct v4l2_fh {
> + struct list_head list;
> + struct video_device *vdev;
> +};
> +
> +void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
> +void v4l2_fh_add(struct v4l2_fh *fh);
> +void v4l2_fh_del(struct v4l2_fh *fh);
> +void v4l2_fh_exit(struct v4l2_fh *fh);
> +
> +void v4l2_fhs_init(struct video_device *vdev);
> +
> +#endif /* V4L2_EVENT_H */
>
@@ -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-subdev.o
+videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-subdev.o \
+ v4l2-fh.o
# V4L2 core modules
@@ -423,6 +423,8 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
if (!vdev->release)
return -EINVAL;
+ v4l2_fhs_init(vdev);
+
/* Part 1: check device type */
switch (type) {
case VFL_TYPE_GRABBER:
new file mode 100644
@@ -0,0 +1,65 @@
+/*
+ * drivers/media/video/v4l2-fh.c
+ *
+ * V4L2 file handles.
+ *
+ * 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-fh.h>
+
+void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
+{
+ fh->vdev = vdev;
+}
+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(&fh->list);
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_del);
+
+void v4l2_fh_exit(struct v4l2_fh *fh)
+{
+ BUG_ON(fh->vdev == NULL);
+ fh->vdev = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_exit);
+
+void v4l2_fhs_init(struct video_device *vdev)
+{
+ spin_lock_init(&vdev->fh_lock);
+ INIT_LIST_HEAD(&vdev->fh_list);
+}
@@ -18,6 +18,8 @@
#include <media/media-entity.h>
+#include <media/v4l2-fh.h>
+
#define VIDEO_MAJOR 81
#define VFL_TYPE_GRABBER 0
@@ -82,6 +84,10 @@ 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 */
new file mode 100644
@@ -0,0 +1,47 @@
+/*
+ * include/media/v4l2-fh.h
+ *
+ * V4L2 file handle.
+ *
+ * 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_FH_H
+#define V4L2_FH_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+#include <asm/atomic.h>
+
+struct video_device;
+
+struct v4l2_fh {
+ struct list_head list;
+ struct video_device *vdev;
+};
+
+void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
+void v4l2_fh_add(struct v4l2_fh *fh);
+void v4l2_fh_del(struct v4l2_fh *fh);
+void v4l2_fh_exit(struct v4l2_fh *fh);
+
+void v4l2_fhs_init(struct video_device *vdev);
+
+#endif /* V4L2_EVENT_H */