Set the capabilities field of v4l2_requestbuffers and v4l2_create_buffers.

The various mapping modes were easy, but for signaling the request capability
a new 'supports_requests' bitfield was added to videobuf2-core.h (and set in
vim2m and vivid). Drivers have to set this bitfield for any queue where
requests are supported.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

VIDIOC_REQBUFS and VIDIOC_CREATE_BUFFERS will return capabilities
telling userspace what the given buffer type is capable of.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Document that V4L2_BUF_FLAG_REQUEST_FD should only be used with
VIDIOC_QBUF and cleared otherwise.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

For now (this might be relaxed in the future) we do not allow getting
controls from a request that isn't completed. In that case we return
-EACCES. Update the documentation accordingly.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Instead of returning -ENOENT when a request_fd was not found (VIDIOC_QBUF
and VIDIOC_G/S/TRY_EXT_CTRLS), we now return -EINVAL. This is in line
with what we do when invalid dmabuf fds are passed to e.g. VIDIOC_QBUF.

Also document that EINVAL is returned for invalid m.fd values, we never
documented that.
Signed-off-by: NHans Verkuil <hansverk@cisco.com>
Reviewed-by: NTomasz Figa <tfiga@chromium.org>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add support for requests to vivid.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add support for the media_device to vivid. This is a prerequisite
for request support.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add support for requests to vim2m.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

v4l2_ctrl uses mutexes, so we can't setup a ctrl_handler in
interrupt context. Switch to a workqueue instead and drop the timer.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

For mem2mem devices we have to make sure that v4l2_m2m_try_schedule()
is called whenever a request is queued.

We do that by creating a vb2_m2m_request_queue() helper that should
be used instead of the 'normal' vb2_request_queue() helper. The m2m
helper function will call v4l2_m2m_try_schedule() as needed.

In addition we also avoid calling v4l2_m2m_try_schedule() when preparing
or queueing a buffer for a request since that is no longer needed.
Instead this helper function will do that when the request is actually
queued.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Check if the vb2 queue uses requests, and if so refuse to
add buffers that are not part of a request. Also check for
the reverse: a vb2 queue did not use requests, and an attempt
was made to queue a buffer to a request.

We might relax this in the future, but for now just return
-EPERM in that case.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Set the first time a buffer from a request is queued to vb2
(uses_requests) or directly queued (uses_qbuf).
Cleared when the queue is canceled.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The generic vb2_request_validate helper function checks if
there are buffers in the request and if so, prepares (validates)
all objects in the request.

The generic vb2_request_queue helper function queues all buffer
objects in the validated request.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add a new helper function to tell if a request object is a buffer.

Add a new helper function that returns true if a media_request
contains at least one buffer.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

This implements the V4L2 part of the request support. The main
change is that vb2_qbuf and vb2_prepare_buf now have a new
media_device pointer. This required changes to several drivers
that did not use the vb2_ioctl_qbuf/prepare_buf helper functions.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Buffers can now be prepared or queued for a request.

A buffer is unbound from the request at vb2_buffer_done time or
when the queue is cancelled.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Make vb2_buffer a request object.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

We need to initialize the request_fd field in struct vb2_v4l2_buffer
to -1 instead of the default of 0. So we need to add a new op that
is called when struct vb2_v4l2_buffer is allocated.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

When queuing buffers allow for passing the request that should
be associated with this buffer.

If V4L2_BUF_FLAG_REQUEST_FD is set, then request_fd is used as
the file descriptor.

If a buffer is stored in a request, but not yet queued to the
driver, then V4L2_BUF_FLAG_IN_REQUEST is set.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The PREPARED state becomes a problem with the request API: a buffer
could be PREPARED but dequeued, or PREPARED and in state IN_REQUEST.

PREPARED is really not a state as such, but more a property of the
buffer. So make new 'prepared' and 'synced' bools instead to remember
whether the buffer is prepared and/or synced or not.

V4L2_BUF_FLAG_PREPARED is only set if the buffer is both synced and
prepared and in the DEQUEUED state.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

There is no need to check the vb2 state in the buf_prepare
callback: it can never be wrong.

Since VB2_BUF_STATE_PREPARED will be removed in the next patch
we'll remove this unnecessary check (and use of that state) first.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The userspace-provided plane data needs to be stored in
vb2_v4l2_buffer. Currently this information is applied by
__fill_vb2_buffer() which is called by the core prepare_buf
and qbuf functions, but when using requests these functions
aren't called yet since the buffer won't be prepared until
the media request is actually queued.

In the meantime this information has to be stored somewhere
and vb2_v4l2_buffer is a good place for it.

The __fill_vb2_buffer callback now just copies the relevant
information from vb2_v4l2_buffer into the planes array.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Replace 'if' statements by a switch in __fill_vb2_buffer()
in preparation of the next patch.

No other changes.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Move the __fill_v4l2_buffer() to before the vb2_queue_or_prepare_buf()
function to prepare for the next two patches.

No other changes.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

If a driver needs to find/inspect the controls set in a request then
it can use these functions.

E.g. to check if a required control is set in a request use this in the
req_validate() implementation:

	int res = -EINVAL;

	hdl = v4l2_ctrl_request_hdl_find(req, parent_hdl);
	if (hdl) {
		if (v4l2_ctrl_request_hdl_ctrl_find(hdl, ctrl_id))
			res = 0;
		v4l2_ctrl_request_hdl_put(hdl);
	}
	return res;
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The v4l2_g/s_ext_ctrls functions now support control handlers that
represent requests.

The v4l2_ctrls_find_req_obj() function is responsible for finding the
request from the fd.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Integrate the request support. This adds the v4l2_ctrl_request_complete
and v4l2_ctrl_request_setup functions to complete a request and (as a
helper function) to apply a request to the hardware.

It takes care of queuing requests and correctly chaining control values
in the request queue.

Note that when a request is marked completed it will copy control values
to the internal request state. This can be optimized in the future since
this is sub-optimal when dealing with large compound and/or array controls.

For the initial 'stateless codec' use-case the current implementation is
sufficient.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

The next patch needs the reference to a control instead of the
control itself, so change struct v4l2_ctrl_helper accordingly.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

To store request data the handler_new_ref() allocates memory
for it if needed.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Embed and initialize a media_request_object in struct v4l2_ctrl_handler.

Add a p_req field to struct v4l2_ctrl_ref that will store the
request value.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NAlexandre Courbot <acourbot@chromium.org>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add a 'bool from_other_dev' argument: set to true if the two
handlers refer to different devices (e.g. it is true when
inheriting controls from a subdev into a main v4l2 bridge
driver).

This will be used later when implementing support for the
request API since we need to skip such controls.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NAlexandre Courbot <acourbot@chromium.org>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

If 'which' is V4L2_CTRL_WHICH_REQUEST_VAL, then the 'request_fd' field
can be used to specify a request for the G/S/TRY_EXT_CTRLS ioctls.
Signed-off-by: NAlexandre Courbot <acourbot@chromium.org>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

We need to serialize streamon/off with queueing new requests.
These ioctls may trigger the cancellation of a streaming
operation, and that should not be mixed with queuing a new
request at the same time.

Finally close() needs this lock since that too can trigger the
cancellation of a streaming operation.

We take the req_queue_mutex here before any other locks since
it is a very high-level lock.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add a simple helper function that tests if the driver supports
the request API.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add media_request_object_find to find a request object inside a
request based on ops and priv values.

Objects of the same type (vb2 buffer, control handler) will have
the same ops value. And objects that refer to the same 'parent'
object (e.g. the v4l2_ctrl_handler that has the current driver
state) will have the same priv value.

The caller has to call media_request_object_put() for the returned
object since this function increments the refcount.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add media_request_get_by_fd() to find a request based on the file
descriptor.

The caller has to call media_request_put() for the returned
request since this function increments the refcount.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

media-request.h has been recently added; add it to the documentation build
as well.
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Add initial media request support:

1) Add MEDIA_IOC_REQUEST_ALLOC ioctl support to media-device.c
2) Add struct media_request to store request objects.
3) Add struct media_request_object to represent a request object.
4) Add MEDIA_REQUEST_IOC_QUEUE/REINIT ioctl support.

Basic lifecycle: the application allocates a request, adds
objects to it, queues the request, polls until it is completed
and can then read the final values of the objects at the time
of completion. When it closes the file descriptor the request
memory will be freed (actually, when the last user of that request
releases the request).

Drivers will bind an object to a request (the 'adds objects to it'
phase), when MEDIA_REQUEST_IOC_QUEUE is called the request is
validated (req_validate op), then queued (the req_queue op).

When done with an object it can either be unbound from the request
(e.g. when the driver has finished with a vb2 buffer) or marked as
completed (e.g. for controls associated with a buffer). When all
objects in the request are completed (or unbound), then the request
fd will signal an exception (poll).
Co-developed-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Co-developed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Co-developed-by: NAlexandre Courbot <acourbot@chromium.org>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Define the public request API.

This adds the new MEDIA_IOC_REQUEST_ALLOC ioctl to allocate a request
and two ioctls that operate on a request in order to queue the
contents of the request to the driver and to re-initialize the
request.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

Document the request API for V4L2 devices, and amend the documentation
of system calls influenced by it.
Signed-off-by: NAlexandre Courbot <acourbot@chromium.org>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>