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: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 2dee93892ea2..bebe44b03e0f 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -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 */