media: mc-device: remove unnecessary __must_check

In the file mc-device.c, the function
media_device_register_entity_notify() does not need to have the
__must_check attribute since it returns only a value of 0.
Therefore, we can remove this attribute and change the function's
return type.

Signed-off-by: Jason Kim <sukbeom.kim@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: mc: entity: Merge media_entity_enum_init and __media_entity_enum_init

The media_entity_enum_init() function is a wrapper around
__media_entity_enum_init() that turns a media_device pointer argument
into the maximum entity ID in the corresponding media graph.
__media_entity_enum_init() is never used outside of
media_entity_enum_init(), so the two functions can be merged together.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: mc: Set bus_info in media_device_init()

Set bus_info field based on struct device in media_device_init() and
remove corresponding code from drivers.

Also update media_device_init() documentation: the dev field must be now
initialised before calling it.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: mc: Provide a helper for setting bus_info field

The bus_info or a similar field exists in a lot of structs, yet drivers
tend to set the value of that field by themselves in a determinable way.
Thus provide a helper for doing this. To be used in subsequent patches.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: mc: media_device_init() initialises a media_device, not media_entity

The documentation for media_device_init() had several references to
(struct) media_entity where it should have referred to struct media_device
instead. Fix this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: mc: Remove redundant documentation

Remove redundant kerneldoc documentation in mc-device.c. The functions are
already documented in media-device.h, where non-redundant documentation is
also moved.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: media-device.h: drop duplicated word in comment

Delete the doubled word "the" in a comment.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: media-request: implement media requests

Add initial media request support:

1) Add MEDIA_IOC_REQUEST_ALLOC ioctl support to media-device.c
2) Add struct media_request to store request objects.
3) Add struct media_request_object to represent a request object.
4) Add MEDIA_REQUEST_IOC_QUEUE/REINIT ioctl support.

Basic lifecycle: the application allocates a request, adds
objects to it, queues the request, polls until it is completed
and can then read the final values of the objects at the time
of completion. When it closes the file descriptor the request
memory will be freed (actually, when the last user of that request
releases the request).

Drivers will bind an object to a request (the 'adds objects to it'
phase), when MEDIA_REQUEST_IOC_QUEUE is called the request is
validated (req_validate op), then queued (the req_queue op).

When done with an object it can either be unbound from the request
(e.g. when the driver has finished with a vb2 buffer) or marked as
completed (e.g. for controls associated with a buffer). When all
objects in the request are completed (or unbound), then the request
fd will signal an exception (poll).

Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Co-developed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Co-developed-by: Alexandre Courbot <acourbot@chromium.org>

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: media-device: remove driver_version

Since the driver_version field in struct media_device is no longer
used, just remove it.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: media-device: set driver_version directly

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: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Protect enable_source and disable_source handler code paths

Drivers might try to access and run enable_source and disable_source
handlers when the driver that implements these handlers is clearing
the handlers during its unregister.

Fix the following race condition:

process 1 process 2

request video streaming unbind au0828
v4l2 checks if tuner is free
... ...

au0828_unregister_media_device()
... ...
(doesn't hold graph_mutex)
mdev->enable_source = NULL;
if (mdev && mdev->enable_source) mdev->disable_source = NULL;
mdev->enable_source()
(enable_source holds graph_mutex)

As shown above enable_source check is done without holding the graph_mutex.
If unbind happens to be in progress, au0828 could clear enable_source and
disable_source handlers leading to null pointer de-reference.

Fix it by protecting enable_source and disable_source set and clear and
protecting enable_source and disable_source handler access and the call
itself.

process 1 process 2

request video streaming unbind au0828
v4l2 checks if tuner is free
... ...

au0828_unregister_media_device()
... ...
(hold graph_mutex while clearing)
mdev->enable_source = NULL;
if (mdev) mdev->disable_source = NULL;
(hold graph_mutex to check and
call enable_source)
if (mdev->enable_source)
mdev->enable_source()

If graph_mutex is held to just heck for handler being null and needs to be
released before calling the handler, there will be another window for the
handlers to be cleared. Hence, enable_source and disable_source handlers
no longer hold the graph_mutex and expect callers to hold it to avoid
forcing them release the graph_mutex before calling the handlers.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Rename graph and pipeline structs and functions

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: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Drop FSF's postal address from the source code files

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: Sakari Ailus <sakari.ailus@linux.intel.com>

[media] media: remove obsolete Media Device Managed resource interfaces

Remove obsolete media_device_get_devres(), media_device_find_devres(),
and media_device_release_devres() interfaces. These interfaces are now
obsolete.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Update documentation for media_entity_notify

Update documentation for media_entity_notify to clearly state the usage
restrictions. This handler is intended for creating links between exiting
entities and should not used to create and register entities.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Move media_device link_notify operation to an ops structure

This will allow adding new operations without increasing the
media_device structure size for drivers that don't implement any media
device operation.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] docs-rst: improve the kAPI documentation for the mediactl

There are several issues on the documentation:
- the media.h header were not properly referenced;
- verbatim expressions were not properly marked as such;
- struct member references were wrong;
- some notes were not using the right markup;
- a comment that were moved to the kernel-doc markup were
duplicated as a comment inside the struct media_entity;
- some args were not pointing to the struct they're using;
- macros weren't documented.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] doc-rst: Fix conversion for MC core functions

There were lots of issues at the media controller side,
after the conversion:

- Some documentation at the header files weren't using the
kernel-doc start block;

- Now, the C files with the exported symbols also need to be
added. So, all headers need to be included twice: one to
get the structs/enums/.. and another one for the functions;

- Notes should use the ReST tag, as kernel-doc doesn't
recognizes it anymore;

- Identation needs to be fixed, as ReST uses it to identify
when a format "tag" ends.

- Fix the cross-references at the media controller description.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] doc-rst: Convert media API to rst

Move the contents of the media section at
DocBooks/DocBook/device-drivers.tmpl to a new ReST book.

For now, the contents is kept as-is. Next patches will fix
the warnings and add cross-references that were removed due to
the conversion.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media-device: dynamically allocate struct media_devnode

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: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: Improve documentation for link_setup/link_modify

Those callbacks are called with the media_device.graph_mutex held.

Add a note about that, as the code called by those notifiers should
not be touching in the mutex.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: get rid of the spinlock

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: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: make topology_version u64

The uAPI defines it with 64 bits. Let's change the Kernel
implementation too.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: Fix a comment

The comment is for the wrong function. Fix it.

Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Always keep a graph walk large enough around

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: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device.h: fix compiler warning

Fix these compiler warnings:

media-git/include/media/media-device.h: In function 'media_device_pci_init':
media-git/include/media/media-device.h:610:9: warning: 'return' with a value, in function returning void
return NULL;
^
media-git/include/media/media-device.h: In function '__media_device_usb_init':
media-git/include/media/media-device.h:618:9: warning: 'return' with a value, in function returning void
return NULL;
^

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Media Controller enable/disable source handler API

Add new fields to struct media_device to add enable_source, and
disable_source handlers, and source_priv to stash driver private
data that is used to run these handlers. The enable_source handler
finds source entity for the passed in entity and checks if it is
available. When link is found, it activates it. Disable source
handler deactivates the link.

Bridge driver is expected to implement and set these handlers.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Media Controller register/unregister entity_notify API

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: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media_device: move allocation out of media_device_*_init

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: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: move PCI/USB helper functions from v4l2-mc

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: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] allow overriding the driver name

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: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device.h: use just one u32 counter for object ID

Instead of using one u32 counter per type for object IDs, use
just one counter. With such change, it makes sense to simplify
the debug logs too.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-entity.h fix documentation for several parameters

Several parameters added by the media_ent_enum patches
were declared with wrong argument names:
include/media/media-device.h:333: warning: No description found for parameter 'entity_internal_idx_max'
include/media/media-device.h:354: warning: No description found for parameter 'ent_enum'
include/media/media-device.h:354: warning: Excess function parameter 'e' description in 'media_entity_enum_init'
include/media/media-device.h:333: warning: No description found for parameter 'entity_internal_idx_max'
include/media/media-device.h:354: warning: No description found for parameter 'ent_enum'
include/media/media-device.h:354: warning: Excess function parameter 'e' description in 'media_entity_enum_init'
include/media/media-entity.h:397: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:397: warning: Excess function parameter 'e' description in 'media_entity_enum_zero'
include/media/media-entity.h:409: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:409: warning: Excess function parameter 'e' description in 'media_entity_enum_set'
include/media/media-entity.h:424: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:424: warning: Excess function parameter 'e' description in 'media_entity_enum_clear'
include/media/media-entity.h:441: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:441: warning: Excess function parameter 'e' description in 'media_entity_enum_test'
include/media/media-entity.h:458: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:458: warning: Excess function parameter 'e' description in 'media_entity_enum_test_and_set'
include/media/media-entity.h:474: warning: No description found for parameter 'ent_enum'
include/media/media-entity.h:474: warning: Excess function parameter 'e' description in 'media_entity_enum_empty'
include/media/media-entity.h:474: warning: Excess function parameter 'entity' description in 'media_entity_enum_empty'
include/media/media-entity.h:489: warning: No description found for parameter 'ent_enum1'
include/media/media-entity.h:489: warning: No description found for parameter 'ent_enum2'
include/media/media-entity.h:489: warning: Excess function parameter 'e' description in 'media_entity_enum_intersects'
include/media/media-entity.h:489: warning: Excess function parameter 'f' description in 'media_entity_enum_intersects'

Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] move documentation to the header files

Some exported functions were still documented at the .c file,
instead of documenting at the .h one.

Move the documentation to the right place, as we only use headers
at media device-drivers.xml DocBook.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Add an API to manage entity enumerations

This is useful in e.g. knowing whether certain operations have already
been performed for an entity. The users include the framework itself (for
graph walking) and a number of drivers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Introduce internal index for media entities

The internal index can be used internally by the framework in order to keep
track of entities for a purpose or another. The internal index is constant
while it's registered to a media device, but the same index may be re-used
once the entity having that index is unregistered.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: split media initialization and registration

The media device node is registered and so made visible to user-space
before entities are registered and links created which means that the
media graph obtained by user-space could be only partially enumerated
if that happens too early before all the graph has been created.

To avoid this race condition, split the media init and registration
in separate functions and only register the media device node when
all the pending subdevices have been registered, either explicitly
by the driver or asynchronously using v4l2_async_register_subdev().

The media_device_register() had a check for drivers not filling dev
and model fields but all drivers in mainline set them and not doing
it will be a driver bug so change the function return to void and
add a BUG_ON() for dev being NULL instead.

Also, add a media_device_cleanup() function that will destroy the
graph_mutex that is initialized in media_device_init().

[mchehab@osg.samsung.com: Fix compilation if !CONFIG_MEDIA_CONTROLLER
and remove two warnings added by this changeset]
Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device.h: document the last functions

Add kernel-doc documentation for media_device_get_devres and
media_device_find_devres.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device.h: Let clearer that entity function must be initialized

Improve the documentation to let it clear that the entity function
must be initialized.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: remove extra blank lines

No functional changes.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device.h: Improve documentation and update it

Now that we moved the content of the media-framework.txt into
the kerneldoc documentation, move the per-function specific
documentation to the corresponding functions and clean it up.

It would be good if we had already the markdown kernel-doc
patches merged upstream, but, while we doesn't have it,
let's make it less ugly at device-drivers.xml.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] DocBook: Move media-framework.txt contents to media-device.h

Instead of using a text file, let's put it together with the
struct documentation for the Media Controller.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-entity: protect object creation/removal using spin lock

Some parts of the media controller are using mutexes while
others are using spin locks in order to protect creation
and removal of elements in the graph. That's wrong!

Also, the V4L2 core can remove graph elements on non-interactive
context:
BUG: sleeping function called from invalid context at include/linux/sched.h:2776

Fix it by always using spin locks for graph element addition/removal,
just like entity creation/removal is protected at media-device.c

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media_device: add a topology version field

Every time a graph object is added or removed, the version
of the topology changes. That's a requirement for the new
MEDIA_IOC_G_TOPOLOGY, in order to allow userspace to know
that the topology has changed after a previous call to it.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media-device: add pads and links to media_device

The MC next gen API sends objects to userspace grouped by
their types.

In the case of pads and links, in order to improve performance
and have a simpler code, the best is to store them also on
separate linked lists at MC.

If we don't do that, we would need this kind of interaction
to send data to userspace (code is in structured english):

for each entity:
for each pad:
store pads

for each entity:
for each link:
store link

for each interface:
for each link:
store link

With would require one nested loop for pads and two nested
loops for links. By using separate linked lists for them,
just one loop would be enough.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: move mdev list init to gobj

Let's control the topology changes inside the graph_object. So, move the
addition and removal of interfaces/entities from the mdev lists to
media_gobj_init() and media_gobj_remove().

The main reason is that mdev should have lists for all object types, as
the new MC api will require to store objects in separate places.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Use a macro to interate between all interfaces

Just like we do with entities, use a similar macro for the
interfaces loop.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: add a linked list to track interfaces by mdev

The media device should list the interface objects, so add a linked list
for those interfaces in struct media_device.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: add functions to allow creating interfaces

Interfaces are different than entities: they represent a
Kernel<->userspace interaction, while entities represent a
piece of hardware/firmware/software that executes a function.

Let's distinguish them by creating a separate structure to
store the interfaces.

Later patches should change the existing drivers and logic
to split the current interface embedded inside the entity
structure (device nodes) into a separate object of the graph.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: use media_gobj inside links

Just like entities and pads, links also need to have unique
Object IDs along a given media controller.

So, let's add a media_gobj inside it and initialize
the object then a new link is created.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: use media_gobj inside pads

PADs also need unique object IDs that won't conflict with
the entity object IDs.

The pad objects are currently created via media_entity_init()
and, once created, never change.

While this will likely change in the future in order to
support dynamic changes, for now we'll keep PADs as arrays
and initialize the media_gobj embedded structs when
registering the entity.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: use media_gobj inside entities

As entities are graph objects, let's embed media_gobj
on it. That ensures an unique ID for entities that can be
global along the entire media controller.

For now, we'll keep the already existing entity ID. Such
field need to be dropped at some point, but for now, let's
not do this, to avoid needing to review all drivers and
the userspace apps.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: define Media Controller API when CONFIG_MEDIA_CONTROLLER enabled

Change to define Media Controller API when CONFIG_MEDIA_CONTROLLER
is enabled. Define stubs for CONFIG_MEDIA_CONTROLLER disabled case.
This will help avoid drivers needing to enclose Media Controller
code within ifdef CONFIG_MEDIA_CONTROLLER block.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: new media controller API for device resource support

Add new media controller API to allocate media device as a
device resource. When a media device is created on the main
struct device which is the parent device for the interface
device, it will be available to all drivers associated with
that interface. For example, if a usb media device driver
creates the media device on the main struct device which is
common for all the drivers that control the media device,
including the non-media ALSA driver, media controller API
can be used to share access to the resources on the media
device. This new interface provides the above described
feature. A second interface that finds and returns the media
device is added to allow drivers to find the media device
created by any of the drivers associated with the device.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] media: Use a better owner for the media device

mdev->fops->owner is actually the owner of the very same module which
implements media_device_register(), so it can't be unloaded anyway. Instead,
use THIS_MODULE through a macro as does video_register_device().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] media: Change media device link_notify behaviour

Currently the media device link_notify callback is invoked before the
actual change of state of a link when the link is being enabled, and
after the actual change of state when the link is being disabled.
This doesn't allow a media device driver to perform any operations
on a full graph before a link is disabled, as well as performing
any tasks on a modified graph right after a link's state is changed.
This patch modifies signature of the link_notify callback. This
callback is now called always before and after a link's state change.
To distinguish the notifications a 'notification' argument is added
to the link_notify callback: MEDIA_DEV_NOTIFY_PRE_LINK_CH indicates
notification before link's state change and
MEDIA_DEV_NOTIFY_POST_LINK_CH corresponds to a notification after
link flags change.

[mchehab@redhat.com: whitespace cleanups]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

device.h: audit and cleanup users in main include dir

The <linux/device.h> header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.

Clean up the users as follows:

1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.

2) For headers not really using anything from device.h, simply
delete the include altogether.

3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h

4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).

Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.

Total removals from #1 and #2: 51. Total additions coming
from #3: 9. Total other implicit dependencies from #4: 7.

As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[media] media: Links setup

Create the following ioctl and implement it at the media device level to
setup links.

- MEDIA_IOC_SETUP_LINK: Modify the properties of a given link

The only property that can currently be modified is the ENABLED link
flag to enable/disable a link. Links marked with the IMMUTABLE link flag
can not be enabled or disabled.

Enabling or disabling a link has effects on entities' use count. Those
changes are automatically propagated through the graph.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] media: Entity use count

Due to the wide differences between drivers regarding power management
needs, the media controller does not implement power management.
However, the media_entity structure includes a use_count field that
media drivers can use to track the number of users of every entity for
power management needs.

The use_count field is owned by media drivers and must not be touched by
entity drivers. Access to the field must be protected by the media
device graph_mutex lock.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] media: Entities, pads and links

As video hardware pipelines become increasingly complex and
configurable, the current hardware description through v4l2 subdevices
reaches its limits. In addition to enumerating and configuring
subdevices, video camera drivers need a way to discover and modify at
runtime how those subdevices are connected. This is done through new
elements called entities, pads and links.

An entity is a basic media hardware building block. It can correspond to
a large variety of logical blocks such as physical hardware devices
(CMOS sensor for instance), logical hardware devices (a building block
in a System-on-Chip image processing pipeline), DMA channels or physical
connectors.

A pad is a connection endpoint through which an entity can interact with
other entities. Data (not restricted to video) produced by an entity
flows from the entity's output to one or more entity inputs. Pads should
not be confused with physical pins at chip boundaries.

A link is a point-to-point oriented connection between two pads, either
on the same entity or on different entities. Data flows from a source
pad to a sink pad.

Links are stored in the source entity. To make backwards graph walk
faster, a copy of all links is also stored in the sink entity. The copy
is known as a backlink and is only used to help graph traversal.

The entity API is made of three functions:

- media_entity_init() initializes an entity. The caller must provide an
array of pads as well as an estimated number of links. The links array
is allocated dynamically and will be reallocated if it grows beyond the
initial estimate.

- media_entity_cleanup() frees resources allocated for an entity. It
must be called during the cleanup phase after unregistering the entity
and before freeing it.

- media_entity_create_link() creates a link between two entities. An
entry in the link array of each entity is allocated and stores pointers
to source and sink pads.

When a media device is unregistered, all its entities are unregistered
automatically.

The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] media: Media device

The media_device structure abstracts functions common to all kind of
media devices (v4l2, dvb, alsa, ...). It manages media entities and
offers a userspace API to discover and configure the media device
internal topology.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>