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authorHans Verkuil <hverkuil@xs4all.nl>2011-01-08 09:38:02 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-03-22 16:37:58 -0300
commitdfddb2441f39e8c0254504516be35b854addf6fa (patch)
tree7fd4bade365e394e38aee0764adca945a5bf394d /include/media
parent73cb42068cff419e72456940c713ceb5efa68c2a (diff)
downloadlinux-dfddb2441f39e8c0254504516be35b854addf6fa.tar.bz2
[media] v4l2-fh: add v4l2_fh_is_singular
Several drivers need to do something when the first filehandle is opened or the last filehandle is closed. Most implement some use count mechanism, but if they use v4l2_fh, then you can also just check if this is the only filehandle for the device node. A simple helper function can do this. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/v4l2-fh.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
index 5657881cd44e..0206aa55be24 100644
--- a/include/media/v4l2-fh.h
+++ b/include/media/v4l2-fh.h
@@ -77,5 +77,18 @@ void v4l2_fh_exit(struct v4l2_fh *fh);
* v4l2_fh struct) is NULL. This function always returns 0.
*/
int v4l2_fh_release(struct file *filp);
+/*
+ * Returns 1 if this filehandle is the only filehandle opened for the
+ * associated video_device. If fh is NULL, then it returns 0.
+ */
+int v4l2_fh_is_singular(struct v4l2_fh *fh);
+/*
+ * Helper function with struct file as argument. If filp->private_data is
+ * NULL, then it will return 0.
+ */
+static inline int v4l2_fh_is_singular_file(struct file *filp)
+{
+ return v4l2_fh_is_singular(filp->private_data);
+}
#endif /* V4L2_EVENT_H */