mirror of https://gitee.com/openkylin/linux.git
[media] v4l: subdev: Add device node support
Create a device node named subdevX for every registered subdev. As the device node is registered before the subdev core::s_config function is called, return -EGAIN on open until initialization completes. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@gmail.com> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Laurent Pinchart
Mauro Carvalho Chehab
parent
0070d91e5b
commit
2096a5dcf9
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@ -319,6 +319,22 @@ controlled through GPIO pins. This distinction is only relevant when setting
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up the device, but once the subdev is registered it is completely transparent.
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V4L2 sub-device userspace API
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-----------------------------
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Beside exposing a kernel API through the v4l2_subdev_ops structure, V4L2
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sub-devices can also be controlled directly by userspace applications.
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Device nodes named v4l-subdevX can be created in /dev to access sub-devices
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directly. If a sub-device supports direct userspace configuration it must set
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the V4L2_SUBDEV_FL_HAS_DEVNODE flag before being registered.
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After registering sub-devices, the v4l2_device driver can create device nodes
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for all registered sub-devices marked with V4L2_SUBDEV_FL_HAS_DEVNODE by calling
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v4l2_device_register_subdev_nodes(). Those device nodes will be automatically
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removed when sub-devices are unregistered.
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I2C sub-device drivers
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----------------------
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@ -11,7 +11,7 @@ stkwebcam-objs := stk-webcam.o stk-sensor.o
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omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o
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videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
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v4l2-event.o v4l2-ctrls.o
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v4l2-event.o v4l2-ctrls.o v4l2-subdev.o
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# V4L2 core modules
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@ -408,13 +408,14 @@ static int get_index(struct video_device *vdev)
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}
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/**
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* video_register_device - register video4linux devices
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* __video_register_device - register video4linux devices
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* @vdev: video device structure we want to register
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* @type: type of device to register
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* @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
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* -1 == first free)
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* @warn_if_nr_in_use: warn if the desired device node number
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* was already in use and another number was chosen instead.
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* @owner: module that owns the video device node
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*
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* The registration code assigns minor numbers and device node numbers
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* based on the requested type and registers the new device node with
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@ -435,9 +436,11 @@ static int get_index(struct video_device *vdev)
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* %VFL_TYPE_VBI - Vertical blank data (undecoded)
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*
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* %VFL_TYPE_RADIO - A radio card
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*
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* %VFL_TYPE_SUBDEV - A subdevice
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*/
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static int __video_register_device(struct video_device *vdev, int type, int nr,
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int warn_if_nr_in_use)
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int __video_register_device(struct video_device *vdev, int type, int nr,
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int warn_if_nr_in_use, struct module *owner)
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{
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int i = 0;
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int ret;
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@ -469,6 +472,9 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
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case VFL_TYPE_RADIO:
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name_base = "radio";
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break;
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case VFL_TYPE_SUBDEV:
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name_base = "v4l-subdev";
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break;
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default:
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printk(KERN_ERR "%s called with unknown type: %d\n",
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__func__, type);
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@ -552,7 +558,7 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
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goto cleanup;
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}
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vdev->cdev->ops = &v4l2_fops;
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vdev->cdev->owner = vdev->fops->owner;
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vdev->cdev->owner = owner;
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ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
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if (ret < 0) {
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printk(KERN_ERR "%s: cdev_add failed\n", __func__);
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@ -597,18 +603,7 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
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vdev->minor = -1;
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return ret;
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}
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int video_register_device(struct video_device *vdev, int type, int nr)
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{
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return __video_register_device(vdev, type, nr, 1);
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}
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EXPORT_SYMBOL(video_register_device);
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int video_register_device_no_warn(struct video_device *vdev, int type, int nr)
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{
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return __video_register_device(vdev, type, nr, 0);
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}
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EXPORT_SYMBOL(video_register_device_no_warn);
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EXPORT_SYMBOL(__video_register_device);
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/**
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* video_unregister_device - unregister a video4linux device
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@ -124,16 +124,20 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
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/* Check for valid input */
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if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
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return -EINVAL;
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/* Warn if we apparently re-register a subdev */
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WARN_ON(sd->v4l2_dev != NULL);
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if (!try_module_get(sd->owner))
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return -ENODEV;
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sd->v4l2_dev = v4l2_dev;
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if (sd->internal_ops && sd->internal_ops->registered) {
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err = sd->internal_ops->registered(sd);
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if (err)
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return err;
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}
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/* This just returns 0 if either of the two args is NULL */
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err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
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if (err) {
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@ -141,24 +145,57 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
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sd->internal_ops->unregistered(sd);
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return err;
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}
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spin_lock(&v4l2_dev->lock);
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list_add_tail(&sd->list, &v4l2_dev->subdevs);
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spin_unlock(&v4l2_dev->lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
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int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
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{
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struct video_device *vdev;
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struct v4l2_subdev *sd;
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int err;
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/* Register a device node for every subdev marked with the
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* V4L2_SUBDEV_FL_HAS_DEVNODE flag.
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*/
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list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
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if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
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continue;
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vdev = &sd->devnode;
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strlcpy(vdev->name, sd->name, sizeof(vdev->name));
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vdev->v4l2_dev = v4l2_dev;
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vdev->fops = &v4l2_subdev_fops;
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vdev->release = video_device_release_empty;
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err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
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sd->owner);
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if (err < 0)
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return err;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
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void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
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{
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/* return if it isn't registered */
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if (sd == NULL || sd->v4l2_dev == NULL)
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return;
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spin_lock(&sd->v4l2_dev->lock);
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list_del(&sd->list);
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spin_unlock(&sd->v4l2_dev->lock);
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if (sd->internal_ops && sd->internal_ops->unregistered)
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sd->internal_ops->unregistered(sd);
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sd->v4l2_dev = NULL;
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video_unregister_device(&sd->devnode);
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module_put(sd->owner);
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}
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EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
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@ -0,0 +1,60 @@
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/*
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* V4L2 subdevice support.
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*
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* Copyright (C) 2010 Nokia Corporation
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*
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* Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/types.h>
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#include <linux/ioctl.h>
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#include <linux/videodev2.h>
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#include <media/v4l2-device.h>
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#include <media/v4l2-ioctl.h>
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static int subdev_open(struct file *file)
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{
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return 0;
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}
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static int subdev_close(struct file *file)
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{
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return 0;
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}
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static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
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{
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switch (cmd) {
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default:
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return -ENOIOCTLCMD;
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}
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return 0;
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}
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static long subdev_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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return video_usercopy(file, cmd, arg, subdev_do_ioctl);
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}
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const struct v4l2_file_operations v4l2_subdev_fops = {
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.owner = THIS_MODULE,
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.open = subdev_open,
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.unlocked_ioctl = subdev_ioctl,
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.release = subdev_close,
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};
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@ -21,7 +21,8 @@
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#define VFL_TYPE_GRABBER 0
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#define VFL_TYPE_VBI 1
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#define VFL_TYPE_RADIO 2
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#define VFL_TYPE_MAX 3
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#define VFL_TYPE_SUBDEV 3
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#define VFL_TYPE_MAX 4
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struct v4l2_ioctl_callbacks;
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struct video_device;
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@ -102,15 +103,26 @@ struct video_device
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/* dev to video-device */
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#define to_video_device(cd) container_of(cd, struct video_device, dev)
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int __must_check __video_register_device(struct video_device *vdev, int type,
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int nr, int warn_if_nr_in_use, struct module *owner);
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/* Register video devices. Note that if video_register_device fails,
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the release() callback of the video_device structure is *not* called, so
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the caller is responsible for freeing any data. Usually that means that
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you call video_device_release() on failure. */
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int __must_check video_register_device(struct video_device *vdev, int type, int nr);
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static inline int __must_check video_register_device(struct video_device *vdev,
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int type, int nr)
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{
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return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
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}
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/* Same as video_register_device, but no warning is issued if the desired
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device node number was already in use. */
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int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
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static inline int __must_check video_register_device_no_warn(
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struct video_device *vdev, int type, int nr)
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{
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return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
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}
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/* Unregister video devices. Will do nothing if vdev == NULL or
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video_is_registered() returns false. */
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@ -96,6 +96,12 @@ int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
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wasn't registered. In that case it will do nothing. */
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void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
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/* Register device nodes for all subdev of the v4l2 device that are marked with
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* the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
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*/
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int __must_check
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v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
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/* Iterate over all subdevs. */
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#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
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list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
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@ -22,6 +22,7 @@
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#define _V4L2_SUBDEV_H
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#include <media/v4l2-common.h>
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#include <media/v4l2-dev.h>
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#include <media/v4l2-mediabus.h>
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/* generic v4l2_device notify callback notification values */
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@ -434,6 +435,8 @@ struct v4l2_subdev_internal_ops {
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#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
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/* Set this flag if this subdev is a spi device. */
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#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
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/* Set this flag if this subdev needs a device node. */
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#define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2)
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/* Each instance of a subdev driver should create this struct, either
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stand-alone or embedded in a larger struct.
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@ -455,8 +458,15 @@ struct v4l2_subdev {
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/* pointer to private data */
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void *dev_priv;
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void *host_priv;
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/* subdev device node */
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struct video_device devnode;
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};
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#define vdev_to_v4l2_subdev(vdev) \
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container_of(vdev, struct v4l2_subdev, devnode)
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extern const struct v4l2_file_operations v4l2_subdev_fops;
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static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
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{
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sd->dev_priv = p;
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