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>