/* * 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 * * 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 #include #include struct video_device; struct v4l2_ctrl_handler; /** * struct v4l2_fh - Describes a V4L2 file handler * * @list: list of file handlers * @vdev: pointer to &struct video_device * @ctrl_handler: pointer to &struct v4l2_ctrl_handler * @prio: priority of the file handler, as defined by &enum v4l2_priority * * @wait: event' s wait queue * @subscribed: list of subscribed events * @available: list of events waiting to be dequeued * @navailable: number of available events at @available list * @sequence: event sequence number * @m2m_ctx: pointer to &struct v4l2_m2m_ctx */ 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; struct list_head available; unsigned int navailable; u32 sequence; #if IS_ENABLED(CONFIG_V4L2_MEM2MEM_DEV) struct v4l2_m2m_ctx *m2m_ctx; #endif }; /** * v4l2_fh_init - Initialise the file handle. * * @fh: pointer to &struct v4l2_fh * @vdev: pointer to &struct video_device * * 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 &struct v4l2_fh. */ void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev); /** * v4l2_fh_add - Add the fh to the list of file handles on a video_device. * * @fh: pointer to &struct v4l2_fh * * .. note:: * The @fh file handle must be initialised first. */ void v4l2_fh_add(struct v4l2_fh *fh); /** * v4l2_fh_open - Ancillary routine that can be used as the open\(\) op * of v4l2_file_operations. * * @filp: pointer to struct file * * It allocates a v4l2_fh and inits and adds it to the &struct video_device * associated with the file pointer. */ int v4l2_fh_open(struct file *filp); /** * v4l2_fh_del - Remove file handle from the list of file handles. * * @fh: pointer to &struct v4l2_fh * * On error filp->private_data will be %NULL, otherwise it will point to * the &struct v4l2_fh. * * .. note:: * Must be called in v4l2_file_operations->release\(\) handler if the driver * uses &struct v4l2_fh. */ void v4l2_fh_del(struct v4l2_fh *fh); /** * v4l2_fh_exit - Release resources related to a file handle. * * @fh: pointer to &struct v4l2_fh * * Parts of the V4L2 framework using the v4l2_fh must release their * resources here, too. * * .. note:: * Must be called in v4l2_file_operations->release\(\) handler if the * driver uses &struct v4l2_fh. */ void v4l2_fh_exit(struct v4l2_fh *fh); /** * v4l2_fh_release - Ancillary routine that can be used as the release\(\) op * of v4l2_file_operations. * * @filp: pointer to struct file * * 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); /** * v4l2_fh_is_singular - Returns 1 if this filehandle is the only filehandle * opened for the associated video_device. * * @fh: pointer to &struct v4l2_fh * * If @fh is NULL, then it returns 0. */ int v4l2_fh_is_singular(struct v4l2_fh *fh); /** * v4l2_fh_is_singular_file - Returns 1 if this filehandle is the only * filehandle opened for the associated video_device. * * @filp: pointer to struct file * * This is a helper function variant of v4l2_fh_is_singular() with uses * 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 */ elect>mode:
Diffstat (limited to 'drivers/usb/storage/usb.h')