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Diffstat (limited to 'include/media/v4l2-fh.h')
| -rw-r--r-- | include/media/v4l2-fh.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h new file mode 100644 index 0000000..a62ee18 --- /dev/null +++ b/include/media/v4l2-fh.h @@ -0,0 +1,101 @@ +/* + * v4l2-fh.h + * + * V4L2 file handle. Store per file handle data for the V4L2 + * framework. Using file handles is optional for the drivers. + * + * Copyright (C) 2009--2010 Nokia Corporation. + * + * Contact: Sakari Ailus <sakari.ailus@iki.fi> + * + * 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/list.h> + +struct video_device; +struct v4l2_ctrl_handler; + +struct v4l2_fh { + struct list_head list; + struct video_device *vdev; + struct v4l2_ctrl_handler *ctrl_handler; + enum v4l2_priority prio; + + /* Events */ + wait_queue_head_t wait; + struct list_head subscribed; /* Subscribed events */ + struct list_head available; /* Dequeueable event */ + unsigned int navailable; + u32 sequence; +}; + +/* + * Initialise the file handle. Parts of the V4L2 framework using the + * file handles should be initialised in this function. Must be called + * from driver's v4l2_file_operations->open() handler if the driver + * uses v4l2_fh. + */ +void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev); +/* + * Add the fh to the list of file handles on a video_device. The file + * 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); +/* + * Release resources related to a file handle. Parts of the V4L2 + * framework using the v4l2_fh must release their resources here, too. + * Must be called in v4l2_file_operations->release() handler if the + * 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); +/* + * 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 */ |