From 1babcb460f2b87c20eb6860b9685a0dab636cc4b Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 23 Mar 2010 09:25:26 -0300 Subject: [PATCH] V4L/DVB: V4L: File handles This patch adds a list of v4l2_fh structures to every video_device. It allows using file handle related information in V4L2. The event interface is one example of such use. The use of v4l2_fh is not mandatory for drivers. Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/Makefile | 2 +- drivers/media/video/v4l2-dev.c | 4 +++ drivers/media/video/v4l2-fh.c | 66 ++++++++++++++++++++++++++++++++++ include/media/v4l2-dev.h | 5 +++ include/media/v4l2-fh.h | 63 ++++++++++++++++++++++++++++++++ 5 files changed, 139 insertions(+), 1 deletion(-) create mode 100644 drivers/media/video/v4l2-fh.c create mode 100644 include/media/v4l2-fh.h diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile index a688a0f43879..c84175c55268 100644 --- a/drivers/media/video/Makefile +++ b/drivers/media/video/Makefile @@ -10,7 +10,7 @@ stkwebcam-objs := stk-webcam.o stk-sensor.o omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o -videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o +videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o # V4L2 core modules diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 709069916068..65a7b30524ca 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -421,6 +421,10 @@ static int __video_register_device(struct video_device *vdev, int type, int nr, if (!vdev->release) return -EINVAL; + /* v4l2_fh support */ + spin_lock_init(&vdev->fh_lock); + INIT_LIST_HEAD(&vdev->fh_list); + /* Part 1: check device type */ switch (type) { case VFL_TYPE_GRABBER: diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c new file mode 100644 index 000000000000..93ea0af5fac1 --- /dev/null +++ b/drivers/media/video/v4l2-fh.c @@ -0,0 +1,66 @@ +/* + * v4l2-fh.c + * + * V4L2 file handles. + * + * 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 + */ + +#include +#include +#include + +int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev) +{ + fh->vdev = vdev; + INIT_LIST_HEAD(&fh->list); + set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags); + + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_fh_init); + +void v4l2_fh_add(struct v4l2_fh *fh) +{ + unsigned long flags; + + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + list_add(&fh->list, &fh->vdev->fh_list); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); +} +EXPORT_SYMBOL_GPL(v4l2_fh_add); + +void v4l2_fh_del(struct v4l2_fh *fh) +{ + unsigned long flags; + + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + list_del_init(&fh->list); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); +} +EXPORT_SYMBOL_GPL(v4l2_fh_del); + +void v4l2_fh_exit(struct v4l2_fh *fh) +{ + if (fh->vdev == NULL) + return; + + fh->vdev = NULL; +} +EXPORT_SYMBOL_GPL(v4l2_fh_exit); diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h index 2dee93892ea2..bebe44b03e0f 100644 --- a/include/media/v4l2-dev.h +++ b/include/media/v4l2-dev.h @@ -32,6 +32,7 @@ struct v4l2_device; Drivers can clear this flag if they want to block all future device access. It is cleared by video_unregister_device. */ #define V4L2_FL_REGISTERED (0) +#define V4L2_FL_USES_V4L2_FH (1) struct v4l2_file_operations { struct module *owner; @@ -77,6 +78,10 @@ struct video_device /* attribute to differentiate multiple indices on one physical device */ int index; + /* V4L2 file handles */ + spinlock_t fh_lock; /* Lock for all v4l2_fhs */ + struct list_head fh_list; /* List of struct v4l2_fh */ + int debug; /* Activates debug level*/ /* Video standard vars */ diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h new file mode 100644 index 000000000000..4aaa1508c8b5 --- /dev/null +++ b/include/media/v4l2-fh.h @@ -0,0 +1,63 @@ +/* + * 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 + +struct video_device; + +struct v4l2_fh { + struct list_head list; + struct video_device *vdev; +}; + +/* + * 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. + */ +int 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); +/* + * Remove file handle from the list of file handles. Must be called in + * v4l2_file_operations->release() handler if the driver uses v4l2_fh. + */ +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); + +#endif /* V4L2_EVENT_H */ -- 2.20.1