Add two new functions: v4l2_fh_open allocates and initializes a struct v4l2_fh
based on a struct file pointer and v4l2_fh_release releases and frees a struct
v4l2_fh.
Signed-off-by: Hans Verkuil <hverkuil@xxxxxxxxx>
---
drivers/media/video/v4l2-fh.c | 28 ++++++++++++++++++++++++++++
include/media/v4l2-fh.h | 15 +++++++++++++++
2 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
index 78a1608..27242e5 100644
--- a/drivers/media/video/v4l2-fh.c
+++ b/drivers/media/video/v4l2-fh.c
@@ -23,6 +23,7 @@
*/
#include <linux/bitops.h>
+#include <linux/slab.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
@@ -60,6 +61,20 @@ void v4l2_fh_add(struct v4l2_fh *fh)
}
EXPORT_SYMBOL_GPL(v4l2_fh_add);
+int v4l2_fh_open(struct file *filp)
+{
+ struct video_device *vdev = video_devdata(filp);
+ struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
+
+ filp->private_data = fh;
+ if (fh == NULL)
+ return -ENOMEM;
+ v4l2_fh_init(fh, vdev);
+ v4l2_fh_add(fh);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_open);
+
void v4l2_fh_del(struct v4l2_fh *fh)
{
unsigned long flags;
@@ -81,3 +96,16 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
v4l2_event_free(fh);
}
EXPORT_SYMBOL_GPL(v4l2_fh_exit);
+
+int v4l2_fh_release(struct file *filp)
+{
+ struct v4l2_fh *fh = filp->private_data;
+
+ if (fh) {
+ v4l2_fh_del(fh);
+ v4l2_fh_exit(fh);
+ kfree(fh);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_fh_release);
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
index 5fc5ba9..5657881 100644
--- a/include/media/v4l2-fh.h
+++ b/include/media/v4l2-fh.h
@@ -51,8 +51,16 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
*/
void v4l2_fh_add(struct v4l2_fh *fh);
/*
+ * Can be used as the open() op of v4l2_file_operations.
+ * It allocates a v4l2_fh and inits and adds it to the video_device associated
+ * with the file pointer.
+ */
+int v4l2_fh_open(struct file *filp);
+/*
* Remove file handle from the list of file handles. Must be called in
* v4l2_file_operations->release() handler if the driver uses v4l2_fh.
+ * On error filp->private_data will be NULL, otherwise it will point to
+ * the v4l2_fh struct.
*/
void v4l2_fh_del(struct v4l2_fh *fh);
/*
@@ -62,5 +70,12 @@ void v4l2_fh_del(struct v4l2_fh *fh);
* driver uses v4l2_fh.
*/
void v4l2_fh_exit(struct v4l2_fh *fh);
+/*
+ * Can be used as the release() op of v4l2_file_operations.
+ * It deletes and exits the v4l2_fh associated with the file pointer and
+ * frees it. It will do nothing if filp->private_data (the pointer to the
+ * v4l2_fh struct) is NULL. This function always returns 0.
+ */
+int v4l2_fh_release(struct file *filp);
#endif /* V4L2_EVENT_H */
--
1.7.0.4
--
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