media: v4l: async: Drop useless list move operation

v4l2_async_unbind_subdev_one(), which is called in the line
following the list_move() operation contains list_move_tail()
for the same entry and overrides anything list_move() did.
Thus it can be removed.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: v4l: async: Fix duplicated list deletion

The list deletion call dropped here is already called from the
helper function in the line before. Having a second list_del()
call results in either a warning (with CONFIG_DEBUG_LIST=y):

list_del corruption, c46c8198->next is LIST_POISON1 (00000100)

If CONFIG_DEBUG_LIST is disabled the operation results in a
kernel error due to NULL pointer dereference.

Fixes: 28a1295795d8 ("media: v4l: async: Allow multiple connections between entities")
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: v4l: async: Avoid a goto in loop implementation

Replace a goto-based loop by a while loop.

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

media: v4l: async: Set v4l2_device and subdev in async notifier init

Set the v4l2_device already in async notifier init, so struct device
related to it will be available before the notifier is registered. This
requires separating notifier initialisation into two functions, one that
takes v4l2_device as its argument, v4l2_async_nf_init and
v4l2_async_subdev_nf_init, for sub-device notifiers. Registering the
notifier will use a single function, v4l2_async_nf_register.

This is done in order to make struct device available earlier, during
construction of the async connections, for sensible debug prints.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Support fwnode endpoint list matching for subdevs

Support matching V4L2 async sub-devices based on particular fwnode
endpoint. This makes it possible to instantiate multiple V4L2 sub-devices
based on given fwnode endpoints from a single device, based on driver
needs.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Try more connections

When an async sub-device is registered, it used to be that the first one
of its connections were matched when found. Continue looking for matches
until a notifier no longer has any.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Drop unneeded list entry initialisation

The list entry is initialised as a head in v4l2_async_register_subdev()
just before being added to the list. This isn't needed, drop the
initialisation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Allow multiple connections between entities

When the v4l2-async framework was introduced, the use case for it was to
connect a camera sensor with a parallel receiver. Both tended to be rather
simple devices with a single connection between them.

The framework has been since improved in multiple ways but there are
limitations that have remained, for instance the assumption an async
sub-device is connected towards a single notifier and via a single link
only.

This patch enables connecting a sub-device to one or more notifiers
simultaneously, with one or more connections per notifier. The notifier
information is moved from the sub-device to the connection and the
connections in sub-device are no longer a pointer but a linked list.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Obtain async connection based on sub-device

Add v4l2_async_connection_unique() function for obtaining a struct
v4l2_async_connection, typically allocated by drivers together with their
own information on an external sub-device.

The relation between connections and sub-devices still remains 1:1 but
this code becomes more complex when the relation soon changes.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Rework internal lists

This patch re-arranges internal V4L2 async lists for preparation of
supporting multiple connections per sub-device as well as cleaning up used
lists.

The list of unbound V4L2 sub-devices shall be maintained for the purpose of
listing those sub-devices only, not for their bindin status. Also, the V4L2
async connections now have, instead of two list entries, a single list
entry in the notifier's list, be that either waiting or done lists, while
the notifier's asc_list is removed.

The one-to-one relation between a sub-device and a connection is still
maintained in this patch.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Drop duplicate handling when adding connections

The connections are checked for duplicates already when the notifier is
registered. This is effectively a sanity check for driver (and possibly
obscure firmware) bugs. Don't do this when adding the connection.

Retain the int return type for now. It'll be needed very soon again.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Clean up error handling in v4l2_async_match_notify

Add labels for error handling instead of doing it all in individual cases.
Prepare for more functionality in this function.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Rename v4l2_async_subdev as v4l2_async_connection

Rename v4l2_async_subdev as v4l2_async_connection, in order to
differentiate between the sub-devices and their connections: one
sub-device can have many connections but the V4L2 async framework has so
far allowed just a single one. Connections in this context will later
translate into either MC ancillary or data links.

This patch prepares changing that relation by changing existing users of
v4l2_async_subdev to switch to v4l2_async_connection. Async sub-devices
themselves will not be needed anymore

Additionally, __v4l2_async_nf_add_subdev() has been renamed
__v4l2_async_nf_add_connection().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Simplify async sub-device fwnode matching

V4L2 async sub-device matching originally used the device nodes only.
Endpoint nodes were taken into use instead as using the device nodes was
problematic for it was in some cases ambiguous which link might have been
in question.

There is however no need to use endpoint nodes on both sides, as the async
sub-device's fwnode can always be trivially obtained using
fwnode_graph_get_remote_endpoint() when needed while what counts is
whether or not the link is between two device nodes, i.e. the device nodes
match.

This will briefly break the adv748x driver but it will be fixed later in
the set, by patch "media: adv748x: Return to endpoint matching".

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Clean up list heads and entries

The naming of list heads and list entries is confusing as they're named
similarly. Use _list for list head and _entry for list entries.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Only pass match information for async subdev validation

Pass only information required for sub-device matching to functions
checking whether the async sub-device already exists. Do the same for
debug message printing. This makes further changes to other aspects of
async sub-devices easier.

Accordingly, also perform further renames:

asd_equal as v4l2_async_match_equal,
v4l2_async_nf_has_async_subdev as v4l2_async_nf_has_async_match,
__v4l2_async_nf_has_async_subdev as
v4l2_async_nf_has_async_subdev_entry and
v4l2_async_nf_asd_valid as v4l2_async_nf_match_valid.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Rename V4L2_ASYNC_MATCH_ macros, add TYPE_

The async match type is a struct field now, rename V4L2_ASYNC_MATCH_*
macros as V4L2_ASYNC_MATCH_TYPE_* instead.

This patch has been produced by:

git grep -l V4L2_ASYNC_MATCH_ -- drivers/media/ drivers/staging/media/ \
include/ Documentation/|xargs perl -i -pe \
's/V4L2_ASYNC_MATCH_\K/TYPE_/g'

so it must be correct.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Make V4L2 async match information a struct

Make V4L2 async match information a struct, making it easier to use it
elsewhere outside the scope of struct v4l2_async_subdev.

Also remove an obsolete comment --- none of these fields are supposed to
be touched by drivers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Don't check whether asd is NULL in validity check

The callers do pass a non-NULL asd to v4l2_async_nf_asd_valid() already.
There's no need for the NULL check here.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Clean up testing for duplicate async subdevs

There's a need to verify that a single async sub-device isn't being added
multiple times, this would be an error. This takes place at the time of
adding the async sub-device to the notifier's list as well as when the
notifier is added to the global notifier's list.

Use the pointer to the sub-device for testing this instead of an index to
an array that is long gone. (There was an array of async sub-devices in
the notifier before it was converted to a linked list by commit
66beb323e4a0 ("media: v4l2: async: Remove notifier subdevs array").)

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Add some debug prints

Just add some debug prints for V4L2 async sub-device matching process.
These might come useful in figuring out why things don't work as expected.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Drop v4l2_async_nf_parse_fwnode_endpoints()

The v4l2_async_nf_parse_fwnode_endpoints() function, part of
v4l2-fwnode.c, was a helper meant to register one async sub-dev for each
fwnode endpoint of a device.

The function is marked as deprecated in the documentation and is actually
not used anywhere anymore. Drop it and remove the helper function
v4l2_async_nf_fwnode_parse_endpoint() from v4l2-fwnode.c.

This change allows to make the helper function
__v4l2_async_nf_add_connection() visibility private to v4l2-async.c so
that there is no risk drivers can mistakenly use it.

[Sakari Ailus: Small fixups on top.]

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Return async sub-devices to subnotifier list

When an async notifier is unregistered, the async sub-devices in the
notifier's done list will disappear with the notifier. However this is
currently also done to the sub-notifiers that remain registered. Their
sub-devices only need to be unbound while the async sub-devices themselves
need to be returned to the sub-notifier's waiting list. Do this now.

Fixes: 2cab00bb076b ("media: v4l: async: Allow binding notifiers to sub-devices")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: v4l2-core: Make the v4l2-core code enable/disable the privacy LED if present

Make v4l2_async_register_subdev_sensor() try to get a privacy LED
associated with the sensor and extend the call_s_stream() wrapper to
enable/disable the privacy LED if found.

This makes the core handle privacy LED control, rather then having to
duplicate this code in all the sensor drivers.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20230127203729.10205-2-hdegoede@redhat.com

media: v4l2-async: Add notifier operation to destroy asd instances

Drivers typically extend the v4l2_async_subdev structure by embedding it
in a driver-specific structure, to store per-subdev custom data. The
v4l2_async_subdev instances are freed by the v4l2-async framework, which
makes this mechanism cumbersome to use safely when custom data needs
special treatment to be destroyed (such as freeing additional memory, or
releasing references to kernel objects).

To ease this, add a .destroy() operation to the
v4l2_async_notifier_operations structure. The operation is called right
before the v4l2_async_subdev is freed, giving drivers a chance to
destroy data if needed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Also match secondary fwnode endpoints

For camera sensor devices the firmware information of which comes from
non-DT (or some ACPI variants), the kernel makes the information visible
to the drivers in a form similar to DT. This takes place through device's
secondary fwnodes, in which case also the secondary fwnode needs to be
heterogenously (endpoint vs. device) matched.

Fixes: 1f391df44607 ("media: v4l2-async: Use endpoints in __v4l2_async_nf_add_fwnode_remote()")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l2-async: Use endpoints in __v4l2_async_nf_add_fwnode_remote()

Matching on device fwnode handles is deprecated in favour of endpoint
fwnode handles. Switch the __v4l2_async_nf_add_fwnode_remote() function
to use the latter. The match code handles backward compatibility by
falling by to the device fwnode handle, so this shouldn't introduce any
regression.

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

media: v4l2-async: Create links during v4l2_async_match_notify()

Upon an async fwnode match, there's some typical behaviour that the
notifier and matching subdev will want to do. For example, a notifier
representing a sensor matching to an async subdev representing its
VCM will want to create an ancillary link to expose that relationship
to userspace.

To avoid lots of code in individual drivers, try to build these links
within v4l2 core.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: v4l: async: Rename async nf functions, clean up long lines

Rename V4L2 async notifier functions, replacing "notifier" with "nf" and
removing "_subdev" at the end of the function names adding subdevs as you
can only add subdevs to a notifier. Also wrap and otherwise clean up long
lines.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com> (imx7)
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l: async, fwnode: Improve module organisation

The V4L2 async framework is generally used with the V4L2 fwnode, which
also depends on the former. There are a few exceptions but they are
relatively few.

At the same time there is a vast number of systems that need videodev
module, but have no use for v4l2-async that's now part of videodev.

In order to improve, split the v4l2-async into its own module. Selecting
V4L2_FWNODE also selects V4L2_ASYNC.

This also moves the initialisation of the debufs entries for async subdevs
to loading of the v4l2-async module. The directory is named as
"v4l2-async".

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Improve v4l2_async_notifier_add_*_subdev() API

The functions that add an async subdev to an async subdev notifier take
as an argument the size of the container structure they need to
allocate. This is error prone, as passing an invalid size will not be
caught by the compiler. Wrap those functions in macros that take a
container type instead of a size, and cast the returned pointer to the
desired type. The compiler will catch mistakes if the incorrect type is
passed to the macro, as the assignment types won't match.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> (core+ti-cal)
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Discourage use of v4l2_async_notifier_add_subdev

Most -if not all- use-cases are expected to be covered by one of:
v4l2_async_notifier_add_fwnode_subdev,
v4l2_async_notifier_add_fwnode_remote_subdev or
v4l2_async_notifier_add_i2c_subdev.

We'd like to discourage drivers from using v4l2_async_notifier_add_subdev,
so rename it as __v4l2_async_notifier_add_subdev. This is
typically a good hint for drivers to avoid using the function.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Clean v4l2_async_notifier_add_fwnode_remote_subdev

Change v4l2_async_notifier_add_fwnode_remote_subdev semantics
so it allocates the struct v4l2_async_subdev pointer.

This makes the API consistent: the v4l2-async subdevice addition
functions have now a unified usage model. This model is simpler,
as it makes v4l2-async responsible for the allocation and release
of the subdevice descriptor, and no longer something the driver
has to worry about.

On the user side, the change makes the API simpler for the drivers
to use and less error-prone.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Remove V4L2_ASYNC_MATCH_DEVNAME

The last user for this type of match was the soc-camera/sh_mobile_csi2
driver, which was removed in v4.9. If the support is ever needed,
it can always be restored.

[Sakari Ailus: Also drop DEVNAME from debug prints recently added.]

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

media: v4l2-async: Safely unregister an non-registered async subdev

Make the V4L2 async framework a bit more robust by allowing to
unregister a non-registered async subdev. Otherwise the
v4l2_async_cleanup() will attempt to delete the async subdev from the
subdev_list with the corresponding list_head not initialized.

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

media: v4l2-async: Add waiting subdevices debugfs

There is currently little to no information available about the reasons
why a v4l2-async device hasn't probed completely.

Inspired by the "devices_deferred" debugfs file, add a file to list
information about the subdevices that are on waiting lists, for each
notifier.

This is useful to debug v4l2-async subdevices and notifiers, for instance
when doing device bring-up.

For instance, a typical output would be:

$ cat /sys/kernel/debug/video4linux/pending_async_subdevices
ipu1_csi1:
[fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi1_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi1_mux
ipu1_csi0:
[fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi0_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi0_mux
imx6-mipi-csi2:
[fwnode] dev=1-003c, node=/soc/bus@2100000/i2c@21a4000/camera@3c
imx-media:

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Remove V4L2_ASYNC_MATCH_CUSTOM

Custom/driver-specific v4l2-async match support was introduced
in 2013, as V4L2_ASYNC_BUS_CUSTOM.

This type of match never had any user, so it's fair
to conclude it's not required and that safe for removal.
If the support is ever needed, it can always be restored.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-core: v4l2-async: Check sd->fwnode->secondary in match_fwnode()

Where the fwnode graph is comprised of software_nodes, these will be
assigned as the secondary to dev->fwnode. Check the v4l2_subdev's fwnode
for a secondary and attempt to match against it during match_fwnode() to
accommodate that possibility.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Log message in case of heterogeneous fwnode match

When a notifier supplies a device fwnode and a subdev supplies an
endpoint fwnode, incorrect matches may occur if multiple subdevs
correspond to the same device fwnode. This can't be handled
transparently in the framework, and requires the notifier to switch to
endpoint fwnodes. Log a message to notify of this problem. A second
message is added to help accelerating the transition to endpoint
matching.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Pass notifier pointer to match functions

The notifier is useful to match functions to access information about
the device matching a subdev. This will be used to print messages using
the correct struct device and driver name.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Accept endpoints and devices for fwnode matching

fwnode matching was designed to match on nodes corresponding to a
device. Some drivers, however, needed to match on endpoints, and have
passed endpoint fwnodes to v4l2-async. This works when both the subdev
and the notifier use the same fwnode types (endpoint or device), but
makes drivers that use different types incompatible.

Fix this by extending the fwnode match to handle fwnodes of different
types. When the types (deduced from the presence of remote endpoints)
are different, retrieve the device fwnode for the side that provides an
endpoint fwnode, and compare it with the device fwnode provided by the
other side. This allows interoperability between all drivers, regardless
of which type of fwnode they use for matching.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: v4l2-async: Safely clean up an uninitialised notifier

Make the V4L2 async framework a bit more robust by allowing to clean up an
uninitialised notifier. Otherwise the result would be a (close to) NULL
pointer dereference.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2-async: Add v4l2_async_notifier_add_fwnode_remote_subdev

v4l2_async_notifier_add_fwnode_remote_subdev is a convenience function for
parsing information on V4L2 fwnode subdevs.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2-async: Get fwnode reference when putting it to the notifier's list

The v4l2_async_notifier_add_fwnode_subdev() did not take a reference of
the added fwnode, relying on the caller to handle that instead, in essence
putting the fwnode to be added if there was an error.

As the reference is eventually released during the notifier cleanup, this
is not intuitive nor logical. Improve this by always getting a reference
when the function succeeds, and the caller releasing the reference when it
does not *itself* need it anymore.

Luckily, perhaps, there were just a handful of callers using the function.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 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 #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: v4l2: async: remove locking when initializing async notifier

There is no need to hold the list_lock when initializing the local
asd_list of a notifier. Remove the lock handling to simplify the code
and remove a potential LOCKDEP warning.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reported-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2-core: cleanup coding style at V4L2 async/fwnode

There are several coding style issues at those definitions,
and the previous patchset added even more.

Address the trivial ones by first calling:

./scripts/checkpatch.pl --strict --fix-inline include/media/v4l2-async.h include/media/v4l2-fwnode.h include/media/v4l2-mediabus.h drivers/media/v4l2-core/v4l2-async.c drivers/media/v4l2-core/v4l2-fwnode.c

and then manually adjusting the style where needed.

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

media: v4l2: async: Remove notifier subdevs array

All platform drivers have been converted to use
v4l2_async_notifier_add_subdev(), in place of adding
asd's to the notifier subdevs array. So the subdevs
array can now be removed from struct v4l2_async_notifier,
and remove the backward compatibility support for that
array in v4l2-async.c.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2-fwnode: Switch to v4l2_async_notifier_add_subdev

The fwnode endpoint and reference parsing functions in v4l2-fwnode.c
are modified to make use of v4l2_async_notifier_add_subdev().
As a result the notifier->subdevs array is no longer allocated or
re-allocated, and by extension the max_subdevs value is also no
longer needed.

Callers of the fwnode endpoint and reference parsing functions must now
first initialize the notifier with a call to v4l2_async_notifier_init().
This includes the function v4l2_async_register_subdev_sensor_common(),
and the intel-ipu3, omap3isp, and rcar-vin drivers.

Since the notifier->subdevs array is no longer allocated in the
fwnode endpoint and reference parsing functions, the callers of
those functions must never reference that array, since it is now
NULL. Of the drivers that make use of the fwnode/ref parsing,
only the intel-ipu3 driver references the ->subdevs[] array,
(in the notifier completion callback), so that driver has been
modified to iterate through the notifier->asd_list instead.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2: async: Add convenience functions to allocate and add asd's

Add these convenience functions, which allocate an asd of match type
fwnode, i2c, or device-name, of size asd_struct_size, and then adds
them to the notifier asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2: async: Add v4l2_async_notifier_add_subdev

v4l2_async_notifier_add_subdev() adds an asd to the notifier. It checks
that no other equivalent asd's have already been added to this notifier's
asd list, or to other registered notifier's waiting or done lists, and
increments num_subdevs.

v4l2_async_notifier_add_subdev() does not make use of the notifier subdevs
array, otherwise it would have to re-allocate the array every time the
function was called. In place of the subdevs array, the function adds
the newly allocated asd to a new master asd_list. The function will
return error with a WARN() if it is ever called with the subdevs array
allocated.

Drivers are now required to call a v4l2_async_notifier_init(), before the
first call to v4l2_async_notifier_add_subdev(), in order to initialize
the asd_list.

In v4l2_async_notifier_has_async_subdev(), __v4l2_async_notifier_register(),
and v4l2_async_notifier_cleanup(), maintain backward compatibility with
the subdevs array, by alternatively operate on the subdevs array or a
non-empty notifier->asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2: async: Allow searching for asd of any type

Generalize v4l2_async_notifier_fwnode_has_async_subdev() to allow
searching for any type of async subdev, not just fwnodes. Rename to
v4l2_async_notifier_has_async_subdev() and pass it an asd pointer.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: v4l2-async: simplify v4l2_async_subdev structure

The V4L2_ASYNC_MATCH_FWNODE match criteria requires just one
struct to be filled (struct fwnode_handle). The V4L2_ASYNC_MATCH_DEVNAME
match criteria requires just a device name.

So, it doesn't make sense to enclose those into structs,
as the criteria can go directly into the union.

That makes easier to document it, as we don't need to document
weird senseless structs.

At drivers, this makes even clearer about the match criteria.

Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Benoit Parrot <bparrot@ti.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Hyun Kwon <hyun.kwon@xilinx.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: use the v4l2_dev from the root notifier when matching sub-devices

When matching and registering a sub-device from a sub-notifier use the
v4l2_device from the root parent notifier. Using the v4l2_dev stored in
the sub-notifier itself is incorrect as it might not be set.

This can be demonstrated by unbinding and rebinding the adv748x driver
and observing that it fails to probe due to the check !v4l2_dev in
v4l2_device_register_subdev().

# echo 4-0070 > /sys/bus/i2c/drivers/adv748x/unbind
# echo 4-0070 > /sys/bus/i2c/drivers/adv748x/bind
adv748x 4-0070: chip found @ 0xe0 revision 2143
adv748x 4-0070: Failed to probe TXA
adv748x: probe of 4-0070 failed with error -22

Looking at the commit which adds sub-notifiers to V4L2 it looks like
this is the intended behavior of the original commit. With this fix the
adv748x can be re-bound and still function properly.

Fixes: 2cab00bb076b9f0e ("media: v4l: async: Allow binding notifiers to sub-devices")

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: fix unregister for implicitly registered sub-device notifiers

The commit aef69d54755d45ed ("media: v4l: fwnode: Add a convenience
function for registering sensors") adds the function
v4l2_async_notifier_parse_fwnode_sensor_common() to parse and register a
subdevice and a subdev-notifier by parsing firmware information. This
new subdev-notifier is stored in the new field 'subdev_notifier' in
struct v4l2_subdev.

In v4l2_async_unregister_subdev() this field is used to unregister and
cleanup the subdev-notifier. A check for if the subdev-notifier is
initialized or not was forgotten leading to a NULL pointer dereference
in v4l2_async_notifier_cleanup() if a subdevice do not use the optional
convince function to initialize the field.

Fix this by checking in v4l2_async_notifier_cleanup() that it is
provided whit a notifier making it safe to call with a NULL parameter.

Fixes: aef69d54755d45ed ("media: v4l: fwnode: Add a convenience function for registering sensors")

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: fix return of unitialized variable ret

A shadow declaration of variable ret is being assigned a return error
status and this value is being lost when the error exit goto's jump
out of the local scope. This leads to an uninitalized error return value
in the outer scope being returned. Fix this by removing the inner scoped
declaration of variable ret.

Detected by CoverityScan, CID#1460380 ("Uninitialized scalar variable")

Fixes: fb45f436b818 ("media: v4l: async: Fix notifier complete callback error handling")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: fwnode: Add a convenience function for registering sensors

Add a convenience function for parsing firmware for information on related
devices using v4l2_async_notifier_parse_fwnode_sensor_common() registering
the notifier and finally the async sub-device itself.

This should be useful for sensor drivers that do not have device specific
requirements related to firmware information parsing or the async
framework.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Ensure only unique fwnodes are registered to notifiers

While registering a notifier, check that each newly added fwnode is
unique, and return an error if it is not. Also check that a newly added
notifier does not have the same fwnodes twice.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Allow binding notifiers to sub-devices

Registering a notifier has required the knowledge of struct v4l2_device
for the reason that sub-devices generally are registered to the
v4l2_device (as well as the media device, also available through
v4l2_device).

This information is not available for sub-device drivers at probe time.

What this patch does is that it allows registering notifiers without
having v4l2_device around. Instead the sub-device pointer is stored in the
notifier. Once the sub-device of the driver that registered the notifier
is registered, the notifier will gain the knowledge of the v4l2_device,
and the binding of async sub-devices from the sub-device driver's notifier
may proceed.

The complete callback of the root notifier will be called only when the
v4l2_device is available and no notifier has pending sub-devices to bind.
No complete callbacks are supported for sub-device notifiers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Prepare for async sub-device notifiers

Refactor the V4L2 async framework a little in preparation for async
sub-device notifiers. This avoids making some structural changes in the
patch actually implementing sub-device notifiers, making that patch easier
to review.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Allow async notifier register call succeed with no subdevs

The information on how many async sub-devices would be bindable to a
notifier is typically dependent on information from platform firmware and
it's not driver's business to be aware of that.

Many V4L2 main drivers are perfectly usable (and useful) without async
sub-devices and so if there aren't any around, just proceed call the
notifier's complete callback immediately without registering the notifier
itself.

If a driver needs to check whether there are async sub-devices available,
it can be done by inspecting the notifier's num_subdevs field which tells
the number of async sub-devices.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Register sub-devices before calling bound callback

Register the sub-device before calling the notifier's bound callback.
Doing this the other way around is problematic as the struct v4l2_device
has not assigned for the sub-device yet and may be required by the bound
callback.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Introduce helpers for calling async ops callbacks

Add three helper functions to call async operations callbacks. Besides
simplifying callbacks, this allows async notifiers to have no ops set,
i.e. it can be left NULL.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Move async subdev notifier operations to a separate structure

The async subdev notifier .bound(), .unbind() and .complete() operations
are function pointers stored directly in the v4l2_async_subdev
structure. As the structure isn't immutable, this creates a potential
security risk as the function pointers are mutable.

To fix this, move the function pointers to a new
v4l2_async_subdev_operations structure that can be made const in
drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: fwnode: Support generic parsing of graph endpoints in a device

Add two functions for parsing devices graph endpoints:
v4l2_async_notifier_parse_fwnode_endpoints and
v4l2_async_notifier_parse_fwnode_endpoints_by_port. The former iterates
over all endpoints whereas the latter only iterates over the endpoints in
a given port.

The former is mostly useful for existing drivers that currently implement
the iteration over all the endpoints themselves whereas the latter is
especially intended for devices with both sinks and sources: async
sub-devices for external devices connected to the device's sources will
have already been set up, or the external sub-devices are part of the
master device.

Depends-on: ("device property: preserve usecount for node passed to of_fwnode_graph_get_port_parent()")

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Use more intuitive names for internal functions

Rename internal functions to make the names of the functions better
describe what they do.

Old name New name
v4l2_async_test_notify v4l2_async_match_notify
v4l2_async_belongs v4l2_async_find_match

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Correctly serialise async sub-device unregistration

The check whether an async sub-device is bound to a notifier was performed
without list_lock held, making it possible for another process to
unbind the async sub-device before the sub-device unregistration function
proceeds to take the lock.

Fix this by first acquiring the lock and then proceeding with the check.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Fix notifier complete callback error handling

The notifier complete callback may return an error. This error code was
simply returned to the caller but never handled properly.

Move calling the complete callback function to the caller from
v4l2_async_test_notify and undo the work that was done either in async
sub-device or async notifier registration.

Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: fix unbind error in v4l2_async_notifier_unregister()

The call to v4l2_async_cleanup() will set sd->asd to NULL so passing it to
notifier->unbind() has no effect and leaves the notifier confused. Call
the unbind() callback prior to cleaning up the subdevice to avoid this.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Don't set sd->dev NULL in v4l2_async_cleanup

v4l2_async_cleanup() is called when the async sub-device is unbound from
the media device. As the pointer is set by the driver registering the
async sub-device, leave the pointer as set by the driver.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: v4l: async: Remove re-probing support

Remove V4L2 async re-probing support. The re-probing support has been
there to support cases where the sub-devices require resources provided by
the main driver's hardware to function, such as clocks.

Reprobing has allowed unbinding and again binding the main driver without
explicitly unbinding the sub-device drivers. This is certainly not a
common need, and the responsibility will be the user's going forward.

An alternative could have been to introduce notifier specific locks.
Considering the complexity of the re-probing and that it isn't really a
solution to a problem but a workaround, remove re-probing instead.

If there is a need to support the clock provider unregister/register cycle
while keeping the clock references in the consumers in the future, this
should be implemented in the clock framework instead, not in V4L2.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: Revert "[media] v4l: async: make v4l2 coexist with devicetree nodes in a dt overlay"

This reverts commit d2180e0cf77dc7a7049671d5d57dfa0a228f83c1.

The commit was flawed in that if the device_node pointers are different,
then in fact a different device is present and the device node could be
different in ways other than full_name.

As Frank Rowand explained:

"When an overlay (1) is removed, all uses and references to the nodes and
properties in that overlay are no longer valid. Any driver that uses any
information from the overlay _must_ stop using any data from the overlay.
Any driver that is bound to a new node in the overlay _must_ unbind. Any
driver that became bound to a pre-existing node that was modified by the
overlay (became bound after the overlay was applied) _must_ adjust itself
to account for any changes to that node when the overlay is removed. One
way to do this is to unbind when notified that the overlay is about to
be removed, then to re-bind after the overlay is completely removed.

If an overlay (2) is subsequently applied, a node with the same
full_name as from overlay (1) may exist. There is no guarantee
that overlay (1) and overlay (2) are the same overlay, even if
that node has the same full_name in both cases."

Also, there's not sufficient overlay support in mainline to actually
remove and re-apply an overlay to hit this condition as overlays can
only be applied from in kernel APIs.

Fixes: d2180e0cf77d ("[media] v4l: async: make v4l2 coexist with devicetree nodes in a dt overlay")

Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Javi Merino <javi.merino@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l2-core: Use kvmalloc() for potentially big allocations

There are multiple places where arrays or otherwise variable sized
buffer are allocated through V4L2 core code, including things like
controls, memory pages, staging buffers for ioctls and so on. Such
allocations can potentially require an order > 0 allocation from the
page allocator, which is not guaranteed to be fulfilled and is likely to
fail on a system with severe memory fragmentation (e.g. a system with
very long uptime).

Since the memory being allocated is intended to be used by the CPU
exclusively, we can consider using vmalloc() as a fallback and this is
exactly what the recently merged kvmalloc() helpers do. A kmalloc() call
is still attempted, even for order > 0 allocations, but it is done
with __GFP_NORETRY and __GFP_NOWARN, with expectation of failing if
requested memory is not available instantly. Only then the vmalloc()
fallback is used. This should give us fast and more reliable allocations
even on systems with higher memory pressure and/or more fragmentation,
while still retaining the same performance level on systems not
suffering from such conditions.

While at it, replace explicit array size calculations on changed
allocations with kvmalloc_array().

Purposedly not touching videobuf1, as it is deprecated, has only few
users remaining and would rather be seen removed instead.

Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l: async: check for v4l2_dev in v4l2_async_notifier_register()

Add a check for v4l2_dev to v4l2_async_notifier_register() as to fail as
early as possible since this will fail later in v4l2_async_test_notify().

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l: Switch from V4L2 OF not V4L2 fwnode API

Switch users of the v4l2_of_ APIs to the more generic v4l2_fwnode_ APIs.
Async OF matching is replaced by fwnode matching and OF matching support
is removed.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Benoit Parrot <bparrot@ti.com> # i2c/ov2569.c, am437x/am437x-vpfe.c and ti-vpe/cal.c
Tested-by: Hans Verkuil <hans.verkuil@cisco.com> # Atmel sama5d3 board + ov2640 sensor
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l: async: Add fwnode match support

Add fwnode matching to complement OF node matching. And fwnode may also be
an OF node.

Do not enable fwnode matching yet. It will replace OF matching soon.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l2-async: failing functions shouldn't have side effects

v4l2-async had several functions doing some operations and then
not undoing the operations in a failure situation. For example,
v4l2_async_test_notify() moved a subdev into notifier's done list
even if registering the subdev (v4l2_device_register_subdev) failed.
If the subdev was allocated and v4l2_async_register_subdev() called
from the driver's probe() function, as usually, the probe()
function freed the allocated subdev and returned a failure.
Nevertheless, the subdev was still left into the notifier's done
list, causing an access to already freed memory when the notifier
was later unregistered.

A hand-edited call trace leaving freed subdevs into the notifier:

v4l2_async_register_notifier(notifier, asd)
cameradrv_probe
sd = devm_kzalloc()
v4l2_async_register_subdev(sd)
v4l2_async_test_notify(notifier, sd, asd)
list_move(sd, &notifier->done)
v4l2_device_register_subdev(notifier->v4l2_dev, sd)
cameradrv_registered(sd) -> fails
->v4l2_async_register_subdev returns failure
->cameradrv_probe returns failure
->devres frees the allocated sd
->sd was freed but it still remains in the notifier's list.

This patch fixes this and several other cases where a failing
function could leave nodes into a linked list while the caller
might free the node due to a failure.

Signed-off-by: Tuukka Toivonen <tuukka.toivonen@intel.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l: async: make v4l2 coexist with devicetree nodes in a dt overlay

In asds configured with V4L2_ASYNC_MATCH_OF, the v4l2 subdev can be
part of a devicetree overlay, for example:

&media_bridge {
...
my_port: port@0 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0>;
ep: endpoint@0 {
remote-endpoint = <&camera0>;
};
};
};

/ {
fragment@0 {
target = <&i2c0>;
__overlay__ {
my_cam {
compatible = "foo,bar";
port {
camera0: endpoint {
remote-endpoint = <&my_port>;
...
};
};
};
};
};
};

Each time the overlay is applied, its of_node pointer will be
different. We are not interested in matching the pointer, what we
want to match is that the path is the one we are expecting. Change to
use of_node_cmp() so that we continue matching after the overlay has
been removed and reapplied.

Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javi Merino <javi.merino@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l2-async: Use kmalloc_array() in v4l2_async_notifier_unregister()

A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l2-async: remove unneeded .registered_async callback

The v4l2_subdev_core_ops .registered_async callback was added to notify
a subdev when its entity has been registered with the media device, to
allow for example to modify the media graph (i.e: adding entities/links).

But that's not needed since there is already a .registered callback in
struct v4l2_subdev_internal_ops that's called after the entity has been
registered with the media device in v4l2_device_register_subdev().

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] v4l2-async: Don't fail if registered_async isn't implemented

After sub-dev registration in v4l2_async_test_notify(), the v4l2-async
core calls the registered_async callback but if a sub-dev driver does
not implement it, v4l2_subdev_call() will return a -ENOIOCTLCMD which
should not be considered an error.

Reported-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Benoit Parrot <bparrot@ti.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] v4l2-async: call registered_async after subdev registration

V4L2 sub-devices might need to do initialization that depends on being
registered with a V4L2 device. As an example, sub-devices with Media
Controller support may need to register entities and create pad links.

Execute the registered_async callback after the sub-device has been
registered with the V4L2 device so the driver can do any needed init.

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

v4l: async: Add a pointer to of_node to struct v4l2_subdev, match it

V4L2 async sub-devices are currently matched (OF case) based on the struct
device_node pointer in struct device. LED devices may have more than one
LED, and in that case the OF node to match is not directly the device's
node, but a LED's node.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

[media] v4l2-async: Don't use dynamic static allocation

Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/v4l2-core/v4l2-async.c:238:1: warning: 'v4l2_async_notifier_unregister' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer.
In this specific case, there's a hard limit imposed by V4L2_MAX_SUBDEVS,
with is currently 128. That means that the buffer size can be up to
128x8 = 1024 bytes (on a 64bits kernel), with is too big for stack.
Worse than that, someone could increase it and cause real troubles.
So, let's use dynamically allocated data, instead.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] v4l2-async: Use proper list head for iteration over registered subdevs

This fixes regression introduced in commit b426b3a660c85faf6e1ca1c92c6d
[media] V4L: Merge struct v4l2_async_subdev_list with struct v4l2_subdev

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] v4l: async: Make it safe to unregister unregistered notifier

Calling v4l2_async_notifier_unregister() on a notifier that hasn't been
registered leads to a crash. To simplify drivers, make it safe to
unregister a notifier that has not been registered.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L: Merge struct v4l2_async_subdev_list with struct v4l2_subdev

By integrating the v4l2-async API internals a bit more with
the core overall the v4l2-async code becomes a bit simpler
and easier to follow.
Acked-and-tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>

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: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L: Rename subdev field of struct v4l2_async_notifier

This is a purely cosmetic change. Since the 'subdev' member
points to an array of subdevs make it more explicit by
renaming to the plural form.
Acked-and-tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>

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: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L: Add V4L2_ASYNC_MATCH_OF subdev matching type

Add support for matching by device_node pointer. This allows
the notifier user to simply pass a list of device_node pointers
corresponding to sub-devices.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L: Rename v4l2_async_bus_* to v4l2_async_match_*

enum v4l2_async_bus_type also selects a method subdevs are matched
in the notification handlers, rename it to v4l2_async_match_type
so V4L2_ASYNC_MATCH_OF entry can be further added for matching by
device tree node pointer.
Acked-and-tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>

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: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L: Drop bus_type check in v4l2-async match functions

These match_* functions are internal callbacks and are always
invoked only after checking asd->bus_type. So drop redundant
checks in match_i2c() and match_platform() functions.
Acked-and-tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>

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: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] V4L2: fix compilation if CONFIG_I2C is undefined

i2c_verify_client() is only available, if I2C is enabled. Fix v4l2-async.c
compilation if I2C is disabled.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] V4L2: support asynchronous subdevice registration

Currently bridge device drivers register devices for all subdevices
synchronously, typically, during their probing. E.g. if an I2C CMOS sensor
is attached to a video bridge device, the bridge driver will create an I2C
device and wait for the respective I2C driver to probe. This makes linking
of devices straight forward, but this approach cannot be used with
intrinsically asynchronous and unordered device registration systems like
the Flattened Device Tree. To support such systems this patch adds an
asynchronous subdevice registration framework to V4L2. To use it respective
(e.g. I2C) subdevice drivers must register themselves with the framework.
A bridge driver on the other hand must register notification callbacks,
that will be called upon various related events.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>