[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>

[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>
Laurent Pinchart · Mauro Carvalho Chehab
1 parent 0070d91e5b
Showing 8 changed files with 158 additions and 22 deletions Side-by-side Diff
Documentation/video4linux/v4l2-framework.txt
drivers/media/video/Makefile
drivers/media/video/v4l2-dev.c
drivers/media/video/v4l2-device.c
drivers/media/video/v4l2-subdev.c
include/media/v4l2-dev.h
include/media/v4l2-device.h
include/media/v4l2-subdev.h
@@ -319,6 +319,22 @@
 up the device, but once the subdev is registered it is completely transparent.
  
  
+V4L2 sub-device userspace API
+-----------------------------
+
+Beside exposing a kernel API through the v4l2_subdev_ops structure, V4L2
+sub-devices can also be controlled directly by userspace applications.
+
+Device nodes named v4l-subdevX can be created in /dev to access sub-devices
+directly. If a sub-device supports direct userspace configuration it must set
+the V4L2_SUBDEV_FL_HAS_DEVNODE flag before being registered.
+
+After registering sub-devices, the v4l2_device driver can create device nodes
+for all registered sub-devices marked with V4L2_SUBDEV_FL_HAS_DEVNODE by calling
+v4l2_device_register_subdev_nodes(). Those device nodes will be automatically
+removed when sub-devices are unregistered.
+
+
 I2C sub-device drivers
 ----------------------
  
@@ -11,7 +11,7 @@
 omap2cam-objs	:=	omap24xxcam.o omap24xxcam-dma.o
  
 videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
-			v4l2-event.o v4l2-ctrls.o
+			v4l2-event.o v4l2-ctrls.o v4l2-subdev.o
  
 # V4L2 core modules
  
@@ -408,13 +408,14 @@
 }
  
 /**
- *	video_register_device - register video4linux devices
+ *	__video_register_device - register video4linux devices
  *	@vdev: video device structure we want to register
  *	@type: type of device to register
  *	@nr:   which device node number (0 == /dev/video0, 1 == /dev/video1, ...
  *             -1 == first free)
  *	@warn_if_nr_in_use: warn if the desired device node number
  *	       was already in use and another number was chosen instead.
+ *	@owner: module that owns the video device node
  *
  *	The registration code assigns minor numbers and device node numbers
  *	based on the requested type and registers the new device node with
  
@@ -435,9 +436,11 @@
  *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
  *
  *	%VFL_TYPE_RADIO - A radio card
+ *
+ *	%VFL_TYPE_SUBDEV - A subdevice
  */
-static int __video_register_device(struct video_device *vdev, int type, int nr,
-		int warn_if_nr_in_use)
+int __video_register_device(struct video_device *vdev, int type, int nr,
+		int warn_if_nr_in_use, struct module *owner)
 {
 	int i = 0;
 	int ret;
@@ -469,6 +472,9 @@
 	case VFL_TYPE_RADIO:
 		name_base = "radio";
 		break;
+	case VFL_TYPE_SUBDEV:
+		name_base = "v4l-subdev";
+		break;
 	default:
 		printk(KERN_ERR "%s called with unknown type: %d\n",
 		       __func__, type);
@@ -552,7 +558,7 @@
 		goto cleanup;
 	}
 	vdev->cdev->ops = &v4l2_fops;
-	vdev->cdev->owner = vdev->fops->owner;
+	vdev->cdev->owner = owner;
 	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
 	if (ret < 0) {
 		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
@@ -597,18 +603,7 @@
 	vdev->minor = -1;
 	return ret;
 }
-
-int video_register_device(struct video_device *vdev, int type, int nr)
-{
-	return __video_register_device(vdev, type, nr, 1);
-}
-EXPORT_SYMBOL(video_register_device);
-
-int video_register_device_no_warn(struct video_device *vdev, int type, int nr)
-{
-	return __video_register_device(vdev, type, nr, 0);
-}
-EXPORT_SYMBOL(video_register_device_no_warn);
+EXPORT_SYMBOL(__video_register_device);
  
 /**
  *	video_unregister_device - unregister a video4linux device
@@ -124,16 +124,20 @@
 	/* Check for valid input */
 	if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
 		return -EINVAL;
+
 	/* Warn if we apparently re-register a subdev */
 	WARN_ON(sd->v4l2_dev != NULL);
+
 	if (!try_module_get(sd->owner))
 		return -ENODEV;
+
 	sd->v4l2_dev = v4l2_dev;
 	if (sd->internal_ops && sd->internal_ops->registered) {
 		err = sd->internal_ops->registered(sd);
 		if (err)
 			return err;
 	}
+
 	/* This just returns 0 if either of the two args is NULL */
 	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
 	if (err) {
  
  
  
  
@@ -141,24 +145,57 @@
 			sd->internal_ops->unregistered(sd);
 		return err;
 	}
+
 	spin_lock(&v4l2_dev->lock);
 	list_add_tail(&sd->list, &v4l2_dev->subdevs);
 	spin_unlock(&v4l2_dev->lock);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
  
+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
+{
+	struct video_device *vdev;
+	struct v4l2_subdev *sd;
+	int err;
+
+	/* Register a device node for every subdev marked with the
+	 * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
+	 */
+	list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
+		if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
+			continue;
+
+		vdev = &sd->devnode;
+		strlcpy(vdev->name, sd->name, sizeof(vdev->name));
+		vdev->v4l2_dev = v4l2_dev;
+		vdev->fops = &v4l2_subdev_fops;
+		vdev->release = video_device_release_empty;
+		err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
+					      sd->owner);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
+
 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
 {
 	/* return if it isn't registered */
 	if (sd == NULL || sd->v4l2_dev == NULL)
 		return;
+
 	spin_lock(&sd->v4l2_dev->lock);
 	list_del(&sd->list);
 	spin_unlock(&sd->v4l2_dev->lock);
 	if (sd->internal_ops && sd->internal_ops->unregistered)
 		sd->internal_ops->unregistered(sd);
 	sd->v4l2_dev = NULL;
+
+	video_unregister_device(&sd->devnode);
 	module_put(sd->owner);
 }
 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
+/*
+ *  V4L2 subdevice support.
+ *
+ *  Copyright (C) 2010 Nokia Corporation
+ *
+ *  Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+
+static int subdev_open(struct file *file)
+{
+	return 0;
+}
+
+static int subdev_close(struct file *file)
+{
+	return 0;
+}
+
+static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
+{
+	switch (cmd) {
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static long subdev_ioctl(struct file *file, unsigned int cmd,
+	unsigned long arg)
+{
+	return video_usercopy(file, cmd, arg, subdev_do_ioctl);
+}
+
+const struct v4l2_file_operations v4l2_subdev_fops = {
+	.owner = THIS_MODULE,
+	.open = subdev_open,
+	.unlocked_ioctl = subdev_ioctl,
+	.release = subdev_close,
+};
@@ -21,7 +21,8 @@
 #define VFL_TYPE_GRABBER	0
 #define VFL_TYPE_VBI		1
 #define VFL_TYPE_RADIO		2
-#define VFL_TYPE_MAX		3
+#define VFL_TYPE_SUBDEV		3
+#define VFL_TYPE_MAX		4
  
 struct v4l2_ioctl_callbacks;
 struct video_device;
  
  
@@ -102,15 +103,26 @@
 /* dev to video-device */
 #define to_video_device(cd) container_of(cd, struct video_device, dev)
  
+int __must_check __video_register_device(struct video_device *vdev, int type,
+		int nr, int warn_if_nr_in_use, struct module *owner);
+
 /* Register video devices. Note that if video_register_device fails,
    the release() callback of the video_device structure is *not* called, so
    the caller is responsible for freeing any data. Usually that means that
    you call video_device_release() on failure. */
-int __must_check video_register_device(struct video_device *vdev, int type, int nr);
+static inline int __must_check video_register_device(struct video_device *vdev,
+		int type, int nr)
+{
+	return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
+}
  
 /* Same as video_register_device, but no warning is issued if the desired
    device node number was already in use. */
-int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
+static inline int __must_check video_register_device_no_warn(
+		struct video_device *vdev, int type, int nr)
+{
+	return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
+}
  
 /* Unregister video devices. Will do nothing if vdev == NULL or
    video_is_registered() returns false. */
@@ -96,6 +96,12 @@
    wasn't registered. In that case it will do nothing. */
 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
  
+/* Register device nodes for all subdev of the v4l2 device that are marked with
+ * the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
+ */
+int __must_check
+v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
+
 /* Iterate over all subdevs. */
 #define v4l2_device_for_each_subdev(sd, v4l2_dev)			\
 	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
@@ -22,6 +22,7 @@
 #define _V4L2_SUBDEV_H
  
 #include <media/v4l2-common.h>
+#include <media/v4l2-dev.h>
 #include <media/v4l2-mediabus.h>
  
 /* generic v4l2_device notify callback notification values */
  
@@ -431,9 +432,11 @@
 #define V4L2_SUBDEV_NAME_SIZE 32
  
 /* Set this flag if this subdev is a i2c device. */
-#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
+#define V4L2_SUBDEV_FL_IS_I2C			(1U << 0)
 /* Set this flag if this subdev is a spi device. */
-#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
+#define V4L2_SUBDEV_FL_IS_SPI			(1U << 1)
+/* Set this flag if this subdev needs a device node. */
+#define V4L2_SUBDEV_FL_HAS_DEVNODE		(1U << 2)
  
 /* Each instance of a subdev driver should create this struct, either
    stand-alone or embedded in a larger struct.
  
@@ -455,7 +458,14 @@
 	/* pointer to private data */
 	void *dev_priv;
 	void *host_priv;
+	/* subdev device node */
+	struct video_device devnode;
 };
+
+#define vdev_to_v4l2_subdev(vdev) \
+	container_of(vdev, struct v4l2_subdev, devnode)
+
+extern const struct v4l2_file_operations v4l2_subdev_fops;
  
 static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
 {
...	...	@@ -319,6 +319,22 @@
319	319	up the device, but once the subdev is registered it is completely transparent.
320	320
321	321
	322	+V4L2 sub-device userspace API
	323	+-----------------------------
	324	+
	325	+Beside exposing a kernel API through the v4l2_subdev_ops structure, V4L2
	326	+sub-devices can also be controlled directly by userspace applications.
	327	+
	328	+Device nodes named v4l-subdevX can be created in /dev to access sub-devices
	329	+directly. If a sub-device supports direct userspace configuration it must set
	330	+the V4L2_SUBDEV_FL_HAS_DEVNODE flag before being registered.
	331	+
	332	+After registering sub-devices, the v4l2_device driver can create device nodes
	333	+for all registered sub-devices marked with V4L2_SUBDEV_FL_HAS_DEVNODE by calling
	334	+v4l2_device_register_subdev_nodes(). Those device nodes will be automatically
	335	+removed when sub-devices are unregistered.
	336	+
	337	+
322	338	I2C sub-device drivers
323	339	----------------------
324	340
...	...	@@ -11,7 +11,7 @@
11	11	omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o
12	12
13	13	videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
14		- v4l2-event.o v4l2-ctrls.o
	14	+ v4l2-event.o v4l2-ctrls.o v4l2-subdev.o
15	15
16	16	# V4L2 core modules
17	17
...	...	@@ -408,13 +408,14 @@
408	408	}
409	409
410	410	/**
411		- * video_register_device - register video4linux devices
	411	+ * __video_register_device - register video4linux devices
412	412	* @vdev: video device structure we want to register
413	413	* @type: type of device to register
414	414	* @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
415	415	* -1 == first free)
416	416	* @warn_if_nr_in_use: warn if the desired device node number
417	417	* was already in use and another number was chosen instead.
	418	+ * @owner: module that owns the video device node
418	419	*
419	420	* The registration code assigns minor numbers and device node numbers
420	421	* based on the requested type and registers the new device node with
421	422
...	...	@@ -435,9 +436,11 @@
435	436	* %VFL_TYPE_VBI - Vertical blank data (undecoded)
436	437	*
437	438	* %VFL_TYPE_RADIO - A radio card
	439	+ *
	440	+ * %VFL_TYPE_SUBDEV - A subdevice
438	441	*/
439		-static int __video_register_device(struct video_device *vdev, int type, int nr,
440		- int warn_if_nr_in_use)
	442	+int __video_register_device(struct video_device *vdev, int type, int nr,
	443	+ int warn_if_nr_in_use, struct module *owner)
441	444	{
442	445	int i = 0;
443	446	int ret;
...	...	@@ -469,6 +472,9 @@
469	472	case VFL_TYPE_RADIO:
470	473	name_base = "radio";
471	474	break;
	475	+ case VFL_TYPE_SUBDEV:
	476	+ name_base = "v4l-subdev";
	477	+ break;
472	478	default:
473	479	printk(KERN_ERR "%s called with unknown type: %d\n",
474	480	__func__, type);
...	...	@@ -552,7 +558,7 @@
552	558	goto cleanup;
553	559	}
554	560	vdev->cdev->ops = &v4l2_fops;
555		- vdev->cdev->owner = vdev->fops->owner;
	561	+ vdev->cdev->owner = owner;
556	562	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
557	563	if (ret < 0) {
558	564	printk(KERN_ERR "%s: cdev_add failed\n", __func__);
...	...	@@ -597,18 +603,7 @@
597	603	vdev->minor = -1;
598	604	return ret;
599	605	}
600		-
601		-int video_register_device(struct video_device *vdev, int type, int nr)
602		-{
603		- return __video_register_device(vdev, type, nr, 1);
604		-}
605		-EXPORT_SYMBOL(video_register_device);
606		-
607		-int video_register_device_no_warn(struct video_device *vdev, int type, int nr)
608		-{
609		- return __video_register_device(vdev, type, nr, 0);
610		-}
611		-EXPORT_SYMBOL(video_register_device_no_warn);
	606	+EXPORT_SYMBOL(__video_register_device);
612	607
613	608	/**
614	609	* video_unregister_device - unregister a video4linux device
...	...	@@ -124,16 +124,20 @@
124	124	/* Check for valid input */
125	125	if (v4l2_dev == NULL \|\| sd == NULL \|\| !sd->name[0])
126	126	return -EINVAL;
	127	+
127	128	/* Warn if we apparently re-register a subdev */
128	129	WARN_ON(sd->v4l2_dev != NULL);
	130	+
129	131	if (!try_module_get(sd->owner))
130	132	return -ENODEV;
	133	+
131	134	sd->v4l2_dev = v4l2_dev;
132	135	if (sd->internal_ops && sd->internal_ops->registered) {
133	136	err = sd->internal_ops->registered(sd);
134	137	if (err)
135	138	return err;
136	139	}
	140	+
137	141	/* This just returns 0 if either of the two args is NULL */
138	142	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
139	143	if (err) {
140	144
141	145
142	146
143	147
...	...	@@ -141,24 +145,57 @@
141	145	sd->internal_ops->unregistered(sd);
142	146	return err;
143	147	}
	148	+
144	149	spin_lock(&v4l2_dev->lock);
145	150	list_add_tail(&sd->list, &v4l2_dev->subdevs);
146	151	spin_unlock(&v4l2_dev->lock);
	152	+
147	153	return 0;
148	154	}
149	155	EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
150	156
	157	+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
	158	+{
	159	+ struct video_device *vdev;
	160	+ struct v4l2_subdev *sd;
	161	+ int err;
	162	+
	163	+ /* Register a device node for every subdev marked with the
	164	+ * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
	165	+ */
	166	+ list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
	167	+ if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
	168	+ continue;
	169	+
	170	+ vdev = &sd->devnode;
	171	+ strlcpy(vdev->name, sd->name, sizeof(vdev->name));
	172	+ vdev->v4l2_dev = v4l2_dev;
	173	+ vdev->fops = &v4l2_subdev_fops;
	174	+ vdev->release = video_device_release_empty;
	175	+ err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
	176	+ sd->owner);
	177	+ if (err < 0)
	178	+ return err;
	179	+ }
	180	+
	181	+ return 0;
	182	+}
	183	+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
	184	+
151	185	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
152	186	{
153	187	/* return if it isn't registered */
154	188	if (sd == NULL \|\| sd->v4l2_dev == NULL)
155	189	return;
	190	+
156	191	spin_lock(&sd->v4l2_dev->lock);
157	192	list_del(&sd->list);
158	193	spin_unlock(&sd->v4l2_dev->lock);
159	194	if (sd->internal_ops && sd->internal_ops->unregistered)
160	195	sd->internal_ops->unregistered(sd);
161	196	sd->v4l2_dev = NULL;
	197	+
	198	+ video_unregister_device(&sd->devnode);
162	199	module_put(sd->owner);
163	200	}
164	201	EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
	1	+/*
	2	+ * V4L2 subdevice support.
	3	+ *
	4	+ * Copyright (C) 2010 Nokia Corporation
	5	+ *
	6	+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License as published by
	10	+ * the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * You should have received a copy of the GNU General Public License
	18	+ * along with this program; if not, write to the Free Software
	19	+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	+ */
	21	+
	22	+#include <linux/types.h>
	23	+#include <linux/ioctl.h>
	24	+#include <linux/videodev2.h>
	25	+
	26	+#include <media/v4l2-device.h>
	27	+#include <media/v4l2-ioctl.h>
	28	+
	29	+static int subdev_open(struct file *file)
	30	+{
	31	+ return 0;
	32	+}
	33	+
	34	+static int subdev_close(struct file *file)
	35	+{
	36	+ return 0;
	37	+}
	38	+
	39	+static long subdev_do_ioctl(struct file file, unsigned int cmd, void arg)
	40	+{
	41	+ switch (cmd) {
	42	+ default:
	43	+ return -ENOIOCTLCMD;
	44	+ }
	45	+
	46	+ return 0;
	47	+}
	48	+
	49	+static long subdev_ioctl(struct file *file, unsigned int cmd,
	50	+ unsigned long arg)
	51	+{
	52	+ return video_usercopy(file, cmd, arg, subdev_do_ioctl);
	53	+}
	54	+
	55	+const struct v4l2_file_operations v4l2_subdev_fops = {
	56	+ .owner = THIS_MODULE,
	57	+ .open = subdev_open,
	58	+ .unlocked_ioctl = subdev_ioctl,
	59	+ .release = subdev_close,
	60	+};
...	...	@@ -21,7 +21,8 @@
21	21	#define VFL_TYPE_GRABBER 0
22	22	#define VFL_TYPE_VBI 1
23	23	#define VFL_TYPE_RADIO 2
24		-#define VFL_TYPE_MAX 3
	24	+#define VFL_TYPE_SUBDEV 3
	25	+#define VFL_TYPE_MAX 4
25	26
26	27	struct v4l2_ioctl_callbacks;
27	28	struct video_device;
28	29
29	30
...	...	@@ -102,15 +103,26 @@
102	103	/* dev to video-device */
103	104	#define to_video_device(cd) container_of(cd, struct video_device, dev)
104	105
	106	+int __must_check __video_register_device(struct video_device *vdev, int type,
	107	+ int nr, int warn_if_nr_in_use, struct module *owner);
	108	+
105	109	/* Register video devices. Note that if video_register_device fails,
106	110	the release() callback of the video_device structure is not called, so
107	111	the caller is responsible for freeing any data. Usually that means that
108	112	you call video_device_release() on failure. */
109		-int __must_check video_register_device(struct video_device *vdev, int type, int nr);
	113	+static inline int __must_check video_register_device(struct video_device *vdev,
	114	+ int type, int nr)
	115	+{
	116	+ return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
	117	+}
110	118
111	119	/* Same as video_register_device, but no warning is issued if the desired
112	120	device node number was already in use. */
113		-int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
	121	+static inline int __must_check video_register_device_no_warn(
	122	+ struct video_device *vdev, int type, int nr)
	123	+{
	124	+ return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
	125	+}
114	126
115	127	/* Unregister video devices. Will do nothing if vdev == NULL or
116	128	video_is_registered() returns false. */
...	...	@@ -96,6 +96,12 @@
96	96	wasn't registered. In that case it will do nothing. */
97	97	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
98	98
	99	+/* Register device nodes for all subdev of the v4l2 device that are marked with
	100	+ * the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
	101	+ */
	102	+int __must_check
	103	+v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
	104	+
99	105	/* Iterate over all subdevs. */
100	106	#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
101	107	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
...	...	@@ -22,6 +22,7 @@
22	22	#define _V4L2_SUBDEV_H
23	23
24	24	#include <media/v4l2-common.h>
	25	+#include <media/v4l2-dev.h>
25	26	#include <media/v4l2-mediabus.h>
26	27
27	28	/* generic v4l2_device notify callback notification values */
28	29
...	...	@@ -431,9 +432,11 @@
431	432	#define V4L2_SUBDEV_NAME_SIZE 32
432	433
433	434	/* Set this flag if this subdev is a i2c device. */
434		-#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
	435	+#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
435	436	/* Set this flag if this subdev is a spi device. */
436		-#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
	437	+#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
	438	+/* Set this flag if this subdev needs a device node. */
	439	+#define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2)
437	440
438	441	/* Each instance of a subdev driver should create this struct, either
439	442	stand-alone or embedded in a larger struct.
440	443
...	...	@@ -455,7 +458,14 @@
455	458	/* pointer to private data */
456	459	void *dev_priv;
457	460	void *host_priv;
	461	+ /* subdev device node */
	462	+ struct video_device devnode;
458	463	};
	464	+
	465	+#define vdev_to_v4l2_subdev(vdev) \
	466	+ container_of(vdev, struct v4l2_subdev, devnode)
	467	+
	468	+extern const struct v4l2_file_operations v4l2_subdev_fops;
459	469
460	470	static inline void v4l2_set_subdevdata(struct v4l2_subdev sd, void p)
461	471	{