The new values were never copied to userspace due to this copy and paste
error. This was introduced during the rewrite of this part of the code in
commit 3219f8a362640b7e4b7e2187b1094c4e46d85aa0.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Normally no control events will go to the filehandle that called the
VIDIOC_S_CTRL/VIDIOC_S_EXT_CTRLS ioctls. This is to prevent a feedback
loop.

This can now be overridden by setting the new V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK
flag.

Based on suggestions from Mauro Carvalho Chehab <mchehab@redhat.com> and
Laurent Pinchart <laurent.pinchart@ideasonboard.com>.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Thanks to Laurent Pinchart <laurent.pinchart@ideasonboard.com>.
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>

Split try_or_set_ext_ctrls() into a validate_ctrls() part ('Phase 1')
and merge the second part ('Phase 2') into try_set_ext_ctrls().

This makes a lot more sense and it also does the validation before
trying to try/set the controls.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The implementation of VIDIOC_G/S/TRY_EXT_CTRLS in the control framework has
to figure out which controls in the control list belong to the same cluster.
Since controls belonging to the same cluster need to be handled as a unit,
this is important information.

It did that by going over the controls in the list and for each control that
belonged to a multi-control cluster it would walk the remainder of the list
to try and find controls that belong to that same cluster.

This approach has two disadvantages:

1) it was a potentially quadratic algorithm (although highly unlikely that
it would ever be that bad in practice).
2) it took place with the control handler's lock held.

Since we want to make it possible in the future to change control values
from interrupt context, doing a lot of work while holding a lock is not a
good idea.

In the new code the algorithm is no longer quadratic but linear in the
number of controls in the list. Also, it now can be done beforehand.

Another change that was made was to so the try and set at the same time.
Before when S_TRY_EXT_CTRLS was called it would 'try' the controls first,
and then it would 'set' them. The idea was that any 'try' errors would
prevent the 'set' from happening, thus avoiding having partially set
control lists.

However, this caused more problems than it solved because between the 'try'
and the 'set' changes might have happened, so it had to try a second time,
and since actual controls with a try_ctrl op are very rare (and those that
we have just adjust values and do not return an error), I've decided to
drop that two-stage approach and just combine try and set.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When sending the SEND_INITIAL event for write-only controls the
V4L2_EVENT_CTRL_CH_VALUE flag should not be set. It's meaningless.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The driver had to decide how many events to allocate when the v4l2_fh struct
was created. It was possible to add more events afterwards, but there was no
way to ensure that you wouldn't miss important events if the event queue
would fill up for that filehandle.

In addition, once there were no more free events, any new events were simply
dropped on the floor.

For the control event in particular this made life very difficult since
control status/value changes could just be missed if the number of allocated
events and the speed at which the application read events was too low to keep
up with the number of generated events. The application would have no idea
what the latest state was for a control since it could have missed the latest
control change.

So this patch makes some major changes in how events are allocated. Instead
of allocating events per-filehandle they are now allocated when subscribing an
event. So for that particular event type N events (determined by the driver)
are allocated. Those events are reserved for that particular event type.
This ensures that you will not miss events for a particular type altogether.

In addition, if there are N events in use and a new event is raised, then
the oldest event is dropped and the new one is added. So the latest event
is always available.

This can be further improved by adding the ability to merge the state of
two events together, ensuring that no data is lost at all. This will be
added in the next patch.

This also makes it possible to allow the user to determine the number of
events that will be allocated. This is not implemented at the moment, but
would be trivial.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The v4l2_ctrl_fh struct connected v4l2_ctrl with v4l2_fh so the control
would know which filehandles subscribed to it. However, it is much easier
to use struct v4l2_subscribed_event directly for that and get rid of that
intermediate struct.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Drivers that supported events used to be rare, but now that controls can also
raise events this will become much more common since almost all drivers have
controls.

This means that keeping struct v4l2_events as a separate struct make no more
sense. Merging it into struct v4l2_fh simplifies things substantially as it
is now an integral part of the filehandle struct.
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>

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

Whenever a control changes value or state an event is sent to anyone
that subscribed to it.

This functionality is useful for control panels but also for applications
that need to wait for (usually status) controls to change value.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When an application changes a control you want to generate an event.
However, you want to avoid sending such an event back to the application
(file handle) that caused the change.

Add the filehandle to the various set control functions.

The filehandle isn't used yet, but the control event patches will need
this.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

It is a bit tricky to handle autogain/gain type scenerios correctly. Such
controls need to be clustered and the V4L2_CTRL_FLAG_UPDATE should be set on
the autofoo controls. In addition, the manual controls should be marked
inactive when the automatic mode is on, and active when the manual mode is on.
This also requires specialized volatile handling.

The chances of drivers doing all these things correctly are pretty remote.
So a new v4l2_ctrl_auto_cluster function was added that takes care of these
issues.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

If you have a cluster of controls that is a mix of volatile and non-volatile
controls, then requesting the value of the volatile control would fail if the
master control of that cluster was non-volatile. The code assumed that the
volatile state of the master control was the same for all other controls in
the cluster.

This is now fixed.

In addition, it was clear from bugs in some drivers that it was confusing that
the ctrl->cur union had to be used in g_volatile_ctrl. Several drivers used the
'new' values instead. The framework was changed so that drivers now set the new
value instead of the current value.

This has an additional benefit as well: the volatile values are now only stored
in the 'new' value, leaving the current value alone. This is useful for
autofoo/foo control clusters where you want to have a 'foo' control act like a
volatile control if 'autofoo' is on, but as a normal control when it is off.

Since with this change the cur value is no longer overwritten when g_volatile_ctrl
is called, you can use it to remember the original 'foo' value. For example:

autofoo = 0, foo = 10 and foo is non-volatile.

Now autofoo is set to 1 and foo is marked volatile. Retrieving the foo value
will get the volatile value. Set autofoo back to 0, which marks foo as non-
volatile again, and retrieving foo will get the old current value of 10.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When applications try to set READ_ONLY controls an error should
be returned. However, when drivers do that it should be accepted.

Those controls could reflect some driver status which the application
can't change but the driver obviously has to be able to change it.

This is needed among others for future HDMI status controls.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The lower-level prepare functions just set error_idx for each control that
might have an error. The high-level functions will override this with
cs->count in the get and set cases. Only try will keep the error_idx.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add the call_op define to safely call the control ops. This also allows
for controls without any ops such as the 'control class' controls.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2-ctl and qv4l2 enumerate controls using V4L2_CTRL_FLAG_NEXT_CTRL,
falling back to the old method if the flag isn't supported.

The v4l2_subdev_queryctrl function will currently handle that flag, but
for the controls of the subdev only. This isn't right, it should refuse
this flag, otherwise v4l2-ctl will only see the controls of the first
subdev.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2_queryctrl sets the step value based on the control type. That would
be fine if it used the control type stored in the V4L2 kernel control
object, not the one stored in the userspace ioctl structure that has
just been memset to 0. Fix this.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When queryctrl is called with a V4L2_CID_PRIVATE_BASE control ID, then
currently it is replaced by the real internal ID. This is not according to
the spec so keep the V4L2_CID_PRIVATE_BASE ID in this case.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

VIDIOC_S_CTRL did not check against read-only controls. Even worse, for
controls of type CTRL_CLASS it would cause a kernel oops since those controls
do not have a s_ctrl op.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Renamed has_new to is_new.

Drivers can use the is_new field to determine if a new value was specified
for a control. The v4l2_ctrl_handler_setup() must always set this to 1 since
the setup has to force a full update of all controls.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The 'def' field is only valid for menus, integers and booleans.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This prevents checkpatch warnings generated when defining
'static const char *foo[]' arrays. It makes sense to use
const char * const * anyway since the pointers in the array
are indeed const.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Some media devices (microscopes) may have one or many illuminators.
This patch makes them controlable by the applications.
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Acked-by: NAndy Walls <awalls@md.metrocast.net>
Signed-off-by: NJean-François Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2-ctrls.c needs to include slab.h to prevent build errors:

drivers/media/video/v4l2-ctrls.c:766: error: implicit declaration of function 'kzalloc'
drivers/media/video/v4l2-ctrls.c:786: error: implicit declaration of function 'kfree'
drivers/media/video/v4l2-ctrls.c:1528: error: implicit declaration of function 'kmalloc'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Fixes 37 checkpatch.pl warnings like:

WARNING: please, no space before tabs
+^Icase V4L2_CID_MPEG_VIDEO_PULLDOWN: ^Ireturn "Video Pulldown";$
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

To make it easier to determine whether all controls are added in v4l2-ctrls.c
the case statements inside the switch are re-ordered to match the header.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add a new framework to handle controls which makes life for driver
developers much easier.

Note that this patch moves some of the control support that used to be in
v4l2-common.c to v4l2-ctrls.c. The tables were copied unchanged. The body
of v4l2_ctrl_query_fill() was copied to a new v4l2_ctrl_fill() function
in v4l2-ctrls.c. This new function doesn't use the v4l2_queryctrl
struct anymore, which makes it more general.

The remainder of v4l2-ctrls.c is all new. Highlights include:

- No need to implement VIDIOC_QUERYCTRL, QUERYMENU, S_CTRL, G_CTRL,
  S_EXT_CTRLS, G_EXT_CTRLS or TRY_EXT_CTRLS in either bridge drivers
  or subdevs. New wrapper functions are provided that can just be plugged in.
  Once everything has been converted these wrapper functions can be removed as well.

- When subdevices are added their controls can be automatically merged
  with the bridge driver's controls.

- Most drivers just need to implement s_ctrl to set the controls.
  The framework handles the locking and tries to be as 'atomic' as possible.

- Ready for the subdev device nodes: the same mechanism applies to subdevs
  and their device nodes as well. Sub-device drivers can make controls
  local, preventing them from being merged with bridge drivers.

- Takes care of backwards compatibility handling of VIDIOC_S_CTRL and
  VIDIOC_G_CTRL. Handling of V4L2_CID_PRIVATE_BASE is fully transparent.
  CTRL_CLASS controls are automatically added.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>