[media] v4l2-fh: add v4l2_fh_open and v4l2_fh_release helper functions (73cb4206) · Commits · 戴 / test

drivers/media/video/v4l2-fh.c

+28 −0

Original line number	Diff line number	Diff line
		@@ -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);

+15 −0

Original line number	Diff line number	Diff line
		@@ -50,9 +50,17 @@ int v4l2_fh_init(struct v4l2_fh fh, struct video_device vdev);
		* handle must be initialised first.
		*/
		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 */