Move the documentation for video device node creation to
a separate file.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Add documentation for v4l2-dev.h, and put it at v4l2-framework.rst,
where struct video_device is currently documented.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

There are two additional subdev-specific sections at the
v4l2-framework file. Move them to the subdev chapter, in order
to better organize the book.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

There are lots of documentation about V4L2 subdevices at
v4l2-framework.rst. Move them to its specific chapter at
v4l2-subdev.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Part of the contents of v4l2-framework is related to the
kAPI defined by v4l2-device. Move such contents to the
v4l2-device.rst.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Make Sphinx happy with v4l2-framework.rst by putting all C
code inside code-block.

Please note that this is a poor man ReST conversion, as several
of those blocks should actually be converted to use :cpp:func:,
pointing to the kAPI auto-generated documentation.

The problem is that we currently lack kernel-doc documentation
for most of the stuff described there.

So, let's do a poor man's conversion. We should later address
this.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Those documentation are part of the kAPI one. Move to the right
place.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

With the new autoksyms support, we can run into a situation where
the v4l pci skeleton module is the only one using some exported
symbols that get dropped because they are never referenced by
the kernel otherwise, causing a build problem:

ERROR: "vb2_dma_contig_memops" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "vb2_dma_contig_init_ctx_attrs" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "v4l2_match_dv_timings" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "v4l2_find_dv_timings_cap" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "v4l2_valid_dv_timings" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "v4l2_enum_dv_timings_cap" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!
ERROR: "vb2_dma_contig_cleanup_ctx" [Documentation/video4linux/v4l2-pci-skeleton.ko] undefined!

Specifically, we do look in the samples directory for users of
symbols, but not the Documentation directory.

This solves the build problem by moving the connector sample into
the same directory as the other samples.

Fixes: 23121ca2 ("kbuild: create/adjust generated/autoksyms.h")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

A small bug with the new autoksyms support showed that there are
two kernel modules in the Documentation directory that qualify
as samples, while all other samples are in the samples/ directory.

This patch was originally meant as a workaround for that bug, but
it has now been solved in a different way. However, I still think
it makes sense as a cleanup to consolidate all sample code in
one place.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

With the MC next gen rework, what's left for media_entity_init()
is to just initialize the PADs. However, certain devices, like
a FLASH led/light doesn't have any input or output PAD.

So, there's no reason why calling media_entity_init() would be
mandatory. Also, despite its name, what this function actually
does is to initialize the PADs data. So, rename it to
media_entity_pads_init() in order to reflect that.

The media entity actual init happens during entity register,
at media_device_register_entity(). We should move init of
num_links and num_backlinks to it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Entities should have one or more functions. Calling it as a
type proofed to not be correct, as an entity could eventually
have more than one type.

So, rename the field as function.

Please notice that this patch doesn't extend support for
multiple function entities. Such change will happen when
we have real case drivers using it.

No functional changes.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Currently, media_entity_init() creates an array with the links,
allocated at init time. It provides a parameter (extra_links)
that would allocate more links than the current needs, but this
is not used by any driver.

As we want to be able to do dynamic link allocation/removal,
we'll need to change the implementation of the links. So,
before doing that, let's first remove that extra unused
parameter, in order to cleanup the interface first.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

All drivers use custom notifications, in particular when source changes.
The bridge only has to map the subdev that sends it to whatever video node it is connected to.
Signed-off-by: NJean-Michel Hautbois <jean-michel.hautbois@vodalys.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The debug attribute was renamed to dev_debug. Update the doc accordingly.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The debug attribute in /sys/class/video4linux/<devX>/debug was never
documented. Add this.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The V4L2_FL_USE_FH_PRIO has been removed from the code, now remove it from the
documentation.
Signed-off-by: NRamakrishnan Muthukrishnan <ramakrmu@cisco.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

This example driver uses all the latest frameworks and can serve as a
starting point for a new V4L2 PCI driver.

Originally written for a presentation on how to use V4L2 frameworks
during FOSDEM 2014.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Add SDR device type to v4l2-framework.txt document.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Add documentation for the V4L2 clock and V4L2 asynchronous probing APIs
to v4l2-framework.txt.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

'parent' was renamed to 'dev_parent'. Clarify how/when this should be used.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The framework documentation used the g_chip_ident op as an example. This
op has been removed, so replace its use in the examples by the g_std op.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from the kernel documentation.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix tense used for describing struct v4l2_fh as it has been added a
while ago.
Signed-off-by: NNicolas Thery <nicolas.thery@st.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

due to structure change for video drivers, change the
description with correct path.
Signed-off-by: NLad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: NManjunath Hadli <manjunath.hadli@ti.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This documents the new queue->lock and how to use it. It also removes the
documentation of v4l2_disable_ioctl_locking: this is only used in gspca and
will be removed once gspca has been converted to vb2.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Rename the function v4l2_dont_use_lock to v4l2_disable_ioctl_locking,
and rename v4l2_dont_use_cmd to v4l2_disable_ioctl.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Thanks to Laurent Pinchart for pointing out that this information was missing.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Using the V4L2 core lock is a very robust method that is usually very good
at doing the right thing. But some drivers, particularly USB drivers, may
want to prevent the core from taking the lock for specific ioctls, particularly
buffer queuing ioctls.

The reason is that certain commands like S_CTRL can take a long time to process
over USB and all the time the core has the lock, preventing VIDIOC_DQBUF from
proceeding, even though a frame may be ready in the queue.

This introduces unwanted latency.

Since the buffer queuing commands often have their own internal lock it is
often not necessary to take the core lock. Drivers can now say that they don't
want the core to take the lock for specific ioctls.

As it is a specific opt-out it makes it clear to the reviewer that those
ioctls will need more care when reviewing.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2_subdev_link_validate() is the default op for validating a link. In V4L2
subdev context, it is used to call a pad op which performs the proper link
check without much extra work.
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Document that format related configuration is done through pad ops in case
the driver does use the media framework.
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Just like with ctrl events, drivers may want to get called back on
listener add / remove for other event types too. Rather then special
casing all of this in subscribe / unsubscribe event it is better to
use ops for this.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Both radio-keene and dsbr100 did one v4l2_device_get too many. Thus the refcount
never became 0 and that causes a memory leak.

Also updated the V4L2 framework documentation accordingly.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

  high-latency devices.

Thanks to Hans de Goede for our discussions on this topic.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Thanks-to: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2_fh_init now returns void instead of int, updated the doc.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Rather than guess which driver supports core priority handling, require drivers
that do to explicitly set the V4L2_FL_USE_FH_PRIO flag in video_device.

Updated the core prio handling accordingly and set the flag in the three
drivers that do.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>