[ Upstream commit 518fa4e0e0da97ea2e17c95ab57647ce748a96e2 ]

You can't memset the contents of a __user pointer. Instead, call copy_to_user to
copy links.reserved (which is zeroed) to the user memory.

This fixes this sparse warning:

SPARSE:drivers/media/mc/mc-device.c drivers/media/mc/mc-device.c:521:16:  warning: incorrect type in argument 1 (different address spaces)

Fixes: f49308878d720 ("media: media_device_enum_links32: clean a reserved field")
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit f49308878d7202e07d8761238e01bd0e5fce2750 ]

In v4l2-compliance utility, test MEDIA_IOC_ENUM_ENTITIES
will check whether reserved field of media_links_enum filled
with zero.

However, for 32 bit program, the reserved field is missing
copy from kernel space to user space in media_device_enum_links32
function.

This patch adds the cleaning a reserved field logic in
media_device_enum_links32 function.
Signed-off-by: NJungo Lin <jungo.lin@mediatek.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Removes a call to ida_pre_get().
Signed-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The media.h public header is one of only three public headers that include
linux/version.h. Drop it from media.h. It was only used for an obsolete
define.

It has to be added to media-device.c, since that source relied on media.h
to include it.
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The v2 entity structure never exposed the entity flags, which made it
impossible to detect connector or default entities.

It is really trivial to just expose this information, so implement this.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The v2 pad structure never exposed the pad index, which made it impossible
to call the MEDIA_IOC_SETUP_LINK ioctl, which needs that information.

It is really trivial to just expose this information, so implement this.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The __NEED_MEDIA_LEGACY_API define is 1) ugly and 2) dangerous
since it is all too easy for drivers to define it to get hold of
legacy defines. Instead just define what we need in media-device.c
which is the only place where we need the legacy define
(MEDIA_ENT_T_DEVNODE_UNKNOWN).
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

This change fixes function types for media device ioctls to avoid
indirect call mismatches with Control-Flow Integrity checking.
Signed-off-by: NSami Tolvanen <samitolvanen@google.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The MEDIA_IOC_G_TOPOLOGY implementation did not zero the reservedX fields.
Fix this.

Found with v4l2-compliance.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

MEDIA_IOC_SETUP_LINK didn't zero the reserved field of the media_link_desc
struct. Do so in media_device_setup_link().

MEDIA_IOC_ENUM_LINKS didn't zero the reserved field of the media_links_enum
struct. Do so in media_device_enum_links().
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

gcc-8 reports

drivers/media/media-device.c: In function 'media_device_get_topology':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified
bound 64 equals destination size [-Wstringop-truncation]

We need to use strlcpy() to make sure the dest string is nul-terminated.
Signed-off-by: NXiongfeng Wang <xiongfeng.wang@linaro.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Set media_version to LINUX_VERSION_CODE, just as we did for
driver_version.

Nobody ever rememebers to update the version number, but
LINUX_VERSION_CODE will always be updated.

Move the MEDIA_API_VERSION define to the ifndef __KERNEL__ section of the
media.h header. That way kernelspace can't accidentally start to use
it again.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Since the driver_version field in struct media_device is no longer
used, just remove it.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Don't use driver_version from struct media_device, just return
LINUX_VERSION_CODE as the other media subsystems do.

The driver_version field in struct media_device will be removed
in the following patches.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Historically, mdev argument name was being used on both struct
media_device and struct media_devnode. Recently most occurrences of mdev
referring to struct media_devnode were replaced by devnode, which makes
more sense. Fix the last remaining occurrence.

Fixes: 163f1e93 ("[media] media-devnode: fix namespace mess")
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Simplify the code to satisfy Linux coding style.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

The media_entity_pipeline_start() and media_entity_pipeline_stop()
functions are renamed as media_pipeline_start() and media_pipeline_stop(),
respectively. The reason is two-fold: the pipeline struct is, rightly,
already called media_pipeline (rather than media_entity_pipeline) and what
this really is about is a pipeline. A pipeline consists of entities ---
and, well, other objects embedded in these entities.

As the pipeline object will be in the future moved from entities to pads
in order to support multiple pipelines through a single entity, do the
renaming now.

Similarly, functions operating on struct media_entity_graph as well as the
struct itself are renamed by dropping the "entity_" part from the prefix
of the function family and the data structure. The graph traversal which
is what the functions are about is not specifically about entities only
and will operate on pads for the same reason as the media pipeline.

The patch has been generated using the following command:

git grep -l media_entity |xargs perl -i -pe '
	s/media_entity_pipeline/media_pipeline/g;
	s/media_entity_graph/media_graph/g'

And a few manual edits related to line start alignment and line wrapping.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Drop the FSF's postal address from the source code files that typically
contain mostly the license text. Of the 628 removed instances, 578 are
outdated.

The patch has been created with the following command without manual edits:

git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \
	drivers/media/ include/media|while read i; do i=$i perl -e '
open(F,"< $ENV{i}");
$a=join("", <F>);
$a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m
	&& $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m;
close(F);
open(F, "> $ENV{i}");
print F $a;
close(F);'; done
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>

When the functions replaced media entity types, the range which was
allowed for the types was incorrect. This meant that media entity types
for specific devices were not passed correctly to the userspace through
MEDIA_IOC_ENUM_ENTITIES. Fix it.

Fixes: commit b2cd2744 ("[media] media-device: map new functions into old types for legacy API")
Reported-and-tested-by: NAntti Laakso <antti.laakso@intel.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@vger.kernel.org # For v4.5 and up
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Remove obsolete media_device_get_devres(), media_device_find_devres(),
and media_device_release_devres() interfaces. These interfaces are now
obsolete.
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

While removing all interfaces in media_device_unregister(), all
media_interface pointers are freed.  This is illegal and results in
double kfree() if any media_interface is still linked at this point;
maybe because a userspace process still has a file handle.  Once the
process closes the file handle, dvb_media_device_free() gets called,
which frees the dvb_device.intf_devnode again.

This patch removes the unnecessary kfree() call, and documents who's
responsible for really freeing it.
Signed-off-by: NMax Kellermann <max.kellermann@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

New IOCTLs (especially for the request API) do not necessarily need the
graph mutex acquired. Leave this up to the drivers.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Refactor copying the IOCTL argument structs from the user space and back,
in order to reduce code copied around and make the implementation more
robust.

As a result, the copying is done while not holding the graph mutex.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Each IOCTL handler can be listed in an array instead of using a large and
cumbersome switch. Do that.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Preparation for refactoring media IOCTL handling to unify common parts.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Media devnode open/ioctl could be in progress when media device unregister
is initiated. System calls and ioctls check media device registered status
at the beginning, however, there is a window where unregister could be in
progress without changing the media devnode status to unregistered.

process 1				process 2
fd = open(/dev/media0)
media_devnode_is_registered()
	(returns true here)

					media_device_unregister()
						(unregister is in progress
						and devnode isn't
						unregistered yet)
					...
ioctl(fd, ...)
__media_ioctl()
media_devnode_is_registered()
	(returns true here)
					...
					media_devnode_unregister()
					...
					(driver releases the media device
					memory)

media_device_ioctl()
	(By this point
	devnode->media_dev does not
	point to allocated memory.
	use-after free in in mutex_lock_nested)

BUG: KASAN: use-after-free in mutex_lock_nested+0x79c/0x800 at addr
ffff8801ebe914f0

Fix it by clearing register bit when unregister starts to avoid the race.

process 1                               process 2
fd = open(/dev/media0)
media_devnode_is_registered()
        (could return true here)

                                        media_device_unregister()
                                                (clear the register bit,
						 then start unregister.)
                                        ...
ioctl(fd, ...)
__media_ioctl()
media_devnode_is_registered()
        (return false here, ioctl
	 returns I/O error, and
	 will not access media
	 device memory)
                                        ...
                                        media_devnode_unregister()
                                        ...
                                        (driver releases the media device
					 memory)
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Suggested-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reported-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Tested-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

When driver unbinds while media_ioctl is in progress, cdev_put() fails with
when app exits after driver unbinds.

Add devnode struct device kobj as the cdev parent kobject. cdev_add() gets
a reference to it and releases it in cdev_del() ensuring that the devnode
is not deallocated as long as the application has the device file open.

media_devnode_register() initializes the struct device kobj before calling
cdev_add(). media_devnode_unregister() does cdev_del() and then deletes the
device. devnode is released when the last reference to the struct device is
gone.

This problem is found on uvcvideo, em28xx, and au0828 drivers and fix has
been tested on all three.

kernel: [  193.599736] BUG: KASAN: use-after-free in cdev_put+0x4e/0x50
kernel: [  193.599745] Read of size 8 by task media_device_te/1851
kernel: [  193.599792] INFO: Allocated in __media_device_register+0x54
kernel: [  193.599951] INFO: Freed in media_devnode_release+0xa4/0xc0

kernel: [  193.601083] Call Trace:
kernel: [  193.601093]  [<ffffffff81aecac3>] dump_stack+0x67/0x94
kernel: [  193.601102]  [<ffffffff815359b2>] print_trailer+0x112/0x1a0
kernel: [  193.601111]  [<ffffffff8153b5e4>] object_err+0x34/0x40
kernel: [  193.601119]  [<ffffffff8153d9d4>] kasan_report_error+0x224/0x530
kernel: [  193.601128]  [<ffffffff814a2c3d>] ? kzfree+0x2d/0x40
kernel: [  193.601137]  [<ffffffff81539d72>] ? kfree+0x1d2/0x1f0
kernel: [  193.601154]  [<ffffffff8157ca7e>] ? cdev_put+0x4e/0x50
kernel: [  193.601162]  [<ffffffff8157ca7e>] cdev_put+0x4e/0x50
kernel: [  193.601170]  [<ffffffff815767eb>] __fput+0x52b/0x6c0
kernel: [  193.601179]  [<ffffffff8117743a>] ? switch_task_namespaces+0x2a
kernel: [  193.601188]  [<ffffffff815769ee>] ____fput+0xe/0x10
kernel: [  193.601196]  [<ffffffff81170023>] task_work_run+0x133/0x1f0
kernel: [  193.601204]  [<ffffffff8117746e>] ? switch_task_namespaces+0x5e
kernel: [  193.601213]  [<ffffffff8111b50c>] do_exit+0x72c/0x2c20
kernel: [  193.601224]  [<ffffffff8111ade0>] ? release_task+0x1250/0x1250
-
-
-
kernel: [  193.601360]  [<ffffffff81003587>] ? exit_to_usermode_loop+0xe7
kernel: [  193.601368]  [<ffffffff810035c0>] exit_to_usermode_loop+0x120
kernel: [  193.601376]  [<ffffffff810061da>] syscall_return_slowpath+0x16a
kernel: [  193.601386]  [<ffffffff82848b33>] entry_SYSCALL_64_fastpath+0xa6
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Tested-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

struct media_devnode is currently embedded at struct media_device.

While this works fine during normal usage, it leads to a race
condition during devnode unregister. the problem is that drivers
assume that, after calling media_device_unregister(), the struct
that contains media_device can be freed. This is not true, as it
can't be freed until userspace closes all opened /dev/media devnodes.

In other words, if the media devnode is still open, and media_device
gets freed, any call to an ioctl will make the core to try to access
struct media_device, with will cause an use-after-free and even GPF.

Fix this by dynamically allocating the struct media_devnode and only
freeing it when it is safe.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Only MEDIA_IOC_ENUM_LINKS32 require an special logic when
userspace is 32 bits and Kernel is 64 bits.

For the rest, media_device_ioctl() will do the right thing,
and will return -ENOIOCTLCMD if the ioctl is unknown.
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

After media_devnode_unregister(), the struct media_device may be freed
already, and dereferencing it may crash.
Signed-off-by: NMax Kellermann <max@duempel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Just checking ifdef CONFIG_USB is not enough, if the USB is compiled
as module. The same applies to PCI.

Tested with the following .config alternatives:

CONFIG_USB=m
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=m
CONFIG_VIDEO_AU0828=m

CONFIG_USB=m
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=m

CONFIG_USB=y
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=m

CONFIG_USB=y
CONFIG_MEDIA_CONTROLLER=y
CONFIG_MEDIA_SUPPORT=y
CONFIG_VIDEO_AU0828=y
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Right now, the lock schema for media_device struct is messy,
since sometimes, it is protected via a spin lock, while, for
media graph traversal, it is protected by a mutex.

Solve this conflict by always using a mutex.

As a side effect, this prevents a bug when the media notifiers
is called at atomic context, while running the notifier callback:

 BUG: sleeping function called from invalid context at mm/slub.c:1289
 in_atomic(): 1, irqs_disabled(): 0, pid: 3479, name: modprobe
 4 locks held by modprobe/3479:
 #0:  (&dev->mutex){......}, at: [<ffffffff81ce8933>] __driver_attach+0xa3/0x160
 #1:  (&dev->mutex){......}, at: [<ffffffff81ce8941>] __driver_attach+0xb1/0x160
 #2:  (register_mutex#5){+.+.+.}, at: [<ffffffffa10596c7>] usb_audio_probe+0x257/0x1c90 [snd_usb_audio]
 #3:  (&(&mdev->lock)->rlock){+.+.+.}, at: [<ffffffffa0e6051b>] media_device_register_entity+0x1cb/0x700 [media]
 CPU: 2 PID: 3479 Comm: modprobe Not tainted 4.5.0-rc3+ #49
 Hardware name:                  /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015
 0000000000000000 ffff8803b3f6f288 ffffffff81933901 ffff8803c4bae000
 ffff8803c4bae5c8 ffff8803b3f6f2b0 ffffffff811c6af5 ffff8803c4bae000
 ffffffff8285d7f6 0000000000000509 ffff8803b3f6f2f0 ffffffff811c6ce5
 Call Trace:
 [<ffffffff81933901>] dump_stack+0x85/0xc4
 [<ffffffff811c6af5>] ___might_sleep+0x245/0x3a0
 [<ffffffff811c6ce5>] __might_sleep+0x95/0x1a0
 [<ffffffff8155aade>] kmem_cache_alloc_trace+0x20e/0x300
 [<ffffffffa0e66e3d>] ? media_add_link+0x4d/0x140 [media]
 [<ffffffffa0e66e3d>] media_add_link+0x4d/0x140 [media]
 [<ffffffffa0e69931>] media_create_pad_link+0xa1/0x600 [media]
 [<ffffffffa0fe11b3>] au0828_media_graph_notify+0x173/0x360 [au0828]
 [<ffffffffa0e68a6a>] ? media_gobj_create+0x1ba/0x480 [media]
 [<ffffffffa0e606fb>] media_device_register_entity+0x3ab/0x700 [media]
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The legacy media controller userspace API exposes entity types that
carry both type and function information. The new API replaces the type
with a function. It preserves backward compatibility by defining legacy
functions for the existing types and using them in drivers.

This works fine, as long as newer entity functions won't be added.

Unfortunately, some tools, like media-ctl with --print-dot argument
rely on the now legacy MEDIA_ENT_T_V4L2_SUBDEV and MEDIA_ENT_T_DEVNODE
numeric ranges to identify what entities will be shown.

Also, if the entity doesn't match those ranges, it will ignore the
major/minor information on devnodes, and won't be getting the devnode
name via udev or sysfs.

As we're now adding devices outside the old range, the legacy ioctl
needs to map the new entity functions into a type at the old range,
or otherwise we'll have a regression.

Detected on all released media-ctl versions (e. g. versions <= 1.10).

Fix this by deriving the type from the function to emulate the legacy
API if the function isn't in the legacy functions range.
Reported-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Mark pointers containing user pointers as such.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media_get_uptr() macro is mostly useful only for the IOCTL handling
code in media-device.c so move it there.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Re-create the graph walk object as needed in order to have one large enough
available for all entities in the graph.

This enumeration is used for pipeline power management in the future.

[mchehab@osg.samsung.com: fix documentation bug:
 " warning: bad line: graph_mutex"]
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add new interfaces to register and unregister entity_notify
hook to media device. These interfaces allow drivers to add
hooks to take appropriate actions when new entities get added
to a shared media device. For example, au0828 bridge driver
registers an entity_notify hook to create links as needed
between media graph nodes.

[mchehab@osg.samsung.com: simple comments should be /* and not /**]
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Right now, media_device_pci_init and media_device_usb_init does
media_device allocation internaly. That preents its usage when
the media_device struct is embedded on some other structure.

Move memory allocation outside it, to make it more generic.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Those ancillary functions could be called even when compiled
without V4L2 support, as warned by ktest build robot:

All errors (new ones prefixed by >>):

>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/dvb-usb/dvb-usb.ko] undefined!
>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/dvb-usb-v2/dvb_usb_v2.ko] undefined!
>> ERROR: "__v4l2_mc_usb_media_device_init" [drivers/media/usb/au0828/au0828.ko] undefined!

Also, there's nothing there that are specific to V4L2. So, move
those ancillary functions to MC core.

No functional changes. Just function rename.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

On USB drivers, the dev struct is usually filled with the USB
device. That would mean that the name of the driver specified
by media_device.dev.driver.name would be "usb", instead of the
name of the actual driver that created the media entity.

Add an optional field at the internal struct to allow drivers
to override the driver name.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>