Just like in userspace strncpy does not guarantee 0 termination. Use strlcpy
instead which does guarantee 0 termination.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Don't issue a stream stop to the camera at the end of sd_start, this fixes
streaming with this particular model.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Based on the old v4l1 camera by Jeroen Vreeken driver which recently got
removed from the kernel.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Reset image and image_len to NULL/0 on LAST_PACKET when we're in discard
frame mode, just like we do when not discarding the current frame.

The new se401 driver uses image_len for SOF/EOF detection and thus depends on
this.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

In the webcam 041e:405f, the LED is inverted.
Signed-off-by: NJean-François Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The sensor of some webcams could not be detected due to timing problems
in sensor register reading. This patch adds bridge register readings
before sensor register reading.
Signed-off-by: NJean-François Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Mauro Carvalho Chehab wrote:
> I'm validating if all drivers are behaving equally with respect to the
> error codes returned to userspace, and double-checking with the API.
>
> On almost all places, -EFAULT code is used only to indicate when
> copy_from_user/copy_to_user fails. However, firedtv uses a lot of
> -EFAULT, where it seems to me that other error codes should be used
> instead (like -EIO for bus transfer errors and -EINVAL/-ERANGE for
> invalid/out of range parameters).

This concerns only the CI (CAM) related code of firedtv of which I know
little.  Let's just pass through the error returns of lower level I/O
code where applicable, and -EACCES (permission denied) when a seemingly
valid but negative FCP response or an unknown-to-firedtv CA message is
received.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Henrik Kurelid <henrik@kurelid.se>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Those drivers are not relying at the V4L2 core to handle the ioctl's.
So, we need to manually patch them every time a change goes to the
core.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-By: NMike Isely <isely@pobox.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Currently, -EINVAL is used to return either when an IOCTL is not
implemented, or if the ioctl was not implemented.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

While here, removes the bogus EINTERNAL error codes.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Move generic stuff into gen-errors.xml, and remove them from
DVB API. While here, removes two bogus error codes that aren't
supported or used on Linux: EINTERNAL and ENOSIGNAL.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When a device (or their PCI structs) are not found, the error should
be -ENODEV. -EFAULT is reserved for errors while copying arguments
from/to userspace.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Remove generic errors from ioctl() descriptions. For other ioctl's,
there's no generic section. So, just keep whatever is there.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Remove generic errors from ioctl() descriptions. For other ioctl's,
there's no generic section. So, just keep whatever is there.
Also remove the EINTERNAL error code, as no DVB driver returns
it, and this error code is not defined on POSIX or on Linux.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Just like the V4L, MC and LIRC API's, point to the generic error
chapter for ioctl's. This will allow moving generic error codes
to just one place inside all media API's.

A latter patch will remove the generic errors from each specific
ioctl.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

data from/to userspace. Don't mix it with I2C bus error (-EIO).
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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

Add a reference for the generic error code chapter to LIRC ioctl
description.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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

V4L ioctl function descripton also has a generic error chapter.
Remove it, as it is now obsoleted by a general, multi-API generic
error descriptions.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The EBUSY is already described as a generic error condition, with a
similar text.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Instead of having their own generic error codes at the MC API, move
its section to the generic one and be sure that all media ioctl's
will point to it.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Be sure that all VIDIOC_* ioctl are using the return error macro, and
aren't specifying generic error codes internally.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

There are several errors reported by V4L that aren't described.
They can occur on almost all ioctl's. Instead of adding them
into each ioctl, create a new chapter.

For V4L, the new chapter will automatically be listed on all
places, as there's a macro used everywhere there.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Scatter/gather DMA mode works nicely on this platform and is clearly the
best way of doing things.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The core Marvell camera driver can now do scatter/gather DMA on controllers
which support that functionality.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
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>

It's getting confusing who is linking to what, so add an overview at
the start of the header.
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>

Starting with v3.1 the V4L2 API provides certain guarantees with respect to
events. Document these.
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>

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>

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>

When the event queue for a subscribed event is full, then the oldest
event is dropped. It would be nice if the contents of that oldest
event could be merged with the next-oldest. That way no information is
lost, only intermediate steps are lost.

This patch adds optional replace() (called when only one kevent was allocated)
and merge() (called when more than one kevent was allocated) callbacks that
will be called to do this job.

These two callbacks are implemented for the V4L2_EVENT_CTRL event.
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>