samples: v4l: from Documentation to samples directory

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: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

4 files changed, 2 insertions, 927 deletions

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 13b5ae1b87aa..de955e151af8 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -1,4 +1,3 @@
 subdir-y := accounting auxdisplay blackfin \
 	filesystems filesystems ia64 laptops mic misc-devices \
-	networking pcmcia prctl ptp timers vDSO video4linux \
-	watchdog
+	networking pcmcia prctl ptp timers vDSO watchdog
diff --git a/Documentation/video4linux/Makefile b/Documentation/video4linux/Makefile
deleted file mode 100644
index 65a351d75c95..000000000000
--- a/Documentation/video4linux/Makefile
+++ /dev/null
@@ -1 +0,0 @@
-obj-$(CONFIG_VIDEO_PCI_SKELETON) := v4l2-pci-skeleton.o
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index fa41608ab2b4..cbefc7902f5f 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -35,7 +35,7 @@ need and this same framework should make it much easier to refactor
 common code into utility functions shared by all drivers.
 
 A good example to look at as a reference is the v4l2-pci-skeleton.c
-source that is available in this directory. It is a skeleton driver for
+source that is available in samples/v4l/. It is a skeleton driver for
 a PCI capture card, and demonstrates how to use the V4L2 driver
 framework. It can be used as a template for real PCI video capture driver.
 
diff --git a/Documentation/video4linux/v4l2-pci-skeleton.c b/Documentation/video4linux/v4l2-pci-skeleton.c
deleted file mode 100644
index 79af0c041056..000000000000
--- a/Documentation/video4linux/v4l2-pci-skeleton.c
+++ /dev/null
@@ -1,923 +0,0 @@
-/*
- * This is a V4L2 PCI Skeleton Driver. It gives an initial skeleton source
- * for use with other PCI drivers.
- *
- * This skeleton PCI driver assumes that the card has an S-Video connector as
- * input 0 and an HDMI connector as input 1.
- *
- * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
- *
- * This program is free software; you may redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/kmod.h>
-#include <linux/mutex.h>
-#include <linux/pci.h>
-#include <linux/interrupt.h>
-#include <linux/videodev2.h>
-#include <linux/v4l2-dv-timings.h>
-#include <media/v4l2-device.h>
-#include <media/v4l2-dev.h>
-#include <media/v4l2-ioctl.h>
-#include <media/v4l2-dv-timings.h>
-#include <media/v4l2-ctrls.h>
-#include <media/v4l2-event.h>
-#include <media/videobuf2-v4l2.h>
-#include <media/videobuf2-dma-contig.h>
-
-MODULE_DESCRIPTION("V4L2 PCI Skeleton Driver");
-MODULE_AUTHOR("Hans Verkuil");
-MODULE_LICENSE("GPL v2");
-
-/**
- * struct skeleton - All internal data for one instance of device
- * @pdev: PCI device
- * @v4l2_dev: top-level v4l2 device struct
- * @vdev: video node structure
- * @ctrl_handler: control handler structure
- * @lock: ioctl serialization mutex
- * @std: current SDTV standard
- * @timings: current HDTV timings
- * @format: current pix format
- * @input: current video input (0 = SDTV, 1 = HDTV)
- * @queue: vb2 video capture queue
- * @alloc_ctx: vb2 contiguous DMA context
- * @qlock: spinlock controlling access to buf_list and sequence
- * @buf_list: list of buffers queued for DMA
- * @sequence: frame sequence counter
- */
-struct skeleton {
-	struct pci_dev *pdev;
-	struct v4l2_device v4l2_dev;
-	struct video_device vdev;
-	struct v4l2_ctrl_handler ctrl_handler;
-	struct mutex lock;
-	v4l2_std_id std;
-	struct v4l2_dv_timings timings;
-	struct v4l2_pix_format format;
-	unsigned input;
-
-	struct vb2_queue queue;
-	struct vb2_alloc_ctx *alloc_ctx;
-
-	spinlock_t qlock;
-	struct list_head buf_list;
-	unsigned field;
-	unsigned sequence;
-};
-
-struct skel_buffer {
-	struct vb2_buffer vb;
-	struct list_head list;
-};
-
-static inline struct skel_buffer *to_skel_buffer(struct vb2_buffer *vb2)
-{
-	return container_of(vb2, struct skel_buffer, vb);
-}
-
-static const struct pci_device_id skeleton_pci_tbl[] = {
-	/* { PCI_DEVICE(PCI_VENDOR_ID_, PCI_DEVICE_ID_) }, */
-	{ 0, }
-};
-MODULE_DEVICE_TABLE(pci, skeleton_pci_tbl);
-
-/*
- * HDTV: this structure has the capabilities of the HDTV receiver.
- * It is used to constrain the huge list of possible formats based
- * upon the hardware capabilities.
- */
-static const struct v4l2_dv_timings_cap skel_timings_cap = {
-	.type = V4L2_DV_BT_656_1120,
-	/* keep this initialization for compatibility with GCC < 4.4.6 */
-	.reserved = { 0 },
-	V4L2_INIT_BT_TIMINGS(
-		720, 1920,		/* min/max width */
-		480, 1080,		/* min/max height */
-		27000000, 74250000,	/* min/max pixelclock*/
-		V4L2_DV_BT_STD_CEA861,	/* Supported standards */
-		/* capabilities */
-		V4L2_DV_BT_CAP_INTERLACED | V4L2_DV_BT_CAP_PROGRESSIVE
-	)
-};
-
-/*
- * Supported SDTV standards. This does the same job as skel_timings_cap, but
- * for standard TV formats.
- */
-#define SKEL_TVNORMS V4L2_STD_ALL
-
-/*
- * Interrupt handler: typically interrupts happen after a new frame has been
- * captured. It is the job of the handler to remove the new frame from the
- * internal list and give it back to the vb2 framework, updating the sequence
- * counter, field and timestamp at the same time.
- */
-static irqreturn_t skeleton_irq(int irq, void *dev_id)
-{
-#ifdef TODO
-	struct skeleton *skel = dev_id;
-
-	/* handle interrupt */
-
-	/* Once a new frame has been captured, mark it as done like this: */
-	if (captured_new_frame) {
-		...
-		spin_lock(&skel->qlock);
-		list_del(&new_buf->list);
-		spin_unlock(&skel->qlock);
-		v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
-		new_buf->vb.v4l2_buf.sequence = skel->sequence++;
-		new_buf->vb.v4l2_buf.field = skel->field;
-		if (skel->format.field == V4L2_FIELD_ALTERNATE) {
-			if (skel->field == V4L2_FIELD_BOTTOM)
-				skel->field = V4L2_FIELD_TOP;
-			else if (skel->field == V4L2_FIELD_TOP)
-				skel->field = V4L2_FIELD_BOTTOM;
-		}
-		vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE);
-	}
-#endif
-	return IRQ_HANDLED;
-}
-
-/*
- * Setup the constraints of the queue: besides setting the number of planes
- * per buffer and the size and allocation context of each plane, it also
- * checks if sufficient buffers have been allocated. Usually 3 is a good
- * minimum number: many DMA engines need a minimum of 2 buffers in the
- * queue and you need to have another available for userspace processing.
- */
-static int queue_setup(struct vb2_queue *vq,
-		       unsigned int *nbuffers, unsigned int *nplanes,
-		       unsigned int sizes[], void *alloc_ctxs[])
-{
-	struct skeleton *skel = vb2_get_drv_priv(vq);
-
-	skel->field = skel->format.field;
-	if (skel->field == V4L2_FIELD_ALTERNATE) {
-		/*
-		 * You cannot use read() with FIELD_ALTERNATE since the field
-		 * information (TOP/BOTTOM) cannot be passed back to the user.
-		 */
-		if (vb2_fileio_is_active(vq))
-			return -EINVAL;
-		skel->field = V4L2_FIELD_TOP;
-	}
-
-	if (vq->num_buffers + *nbuffers < 3)
-		*nbuffers = 3 - vq->num_buffers;
-	alloc_ctxs[0] = skel->alloc_ctx;
-
-	if (*nplanes)
-		return sizes[0] < skel->format.sizeimage ? -EINVAL : 0;
-	*nplanes = 1;
-	sizes[0] = skel->format.sizeimage;
-	return 0;
-}
-
-/*
- * Prepare the buffer for queueing to the DMA engine: check and set the
- * payload size.
- */
-static int buffer_prepare(struct vb2_buffer *vb)
-{
-	struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
-	unsigned long size = skel->format.sizeimage;
-
-	if (vb2_plane_size(vb, 0) < size) {
-		dev_err(&skel->pdev->dev, "buffer too small (%lu < %lu)\n",
-			 vb2_plane_size(vb, 0), size);
-		return -EINVAL;
-	}
-
-	vb2_set_plane_payload(vb, 0, size);
-	return 0;
-}
-
-/*
- * Queue this buffer to the DMA engine.
- */
-static void buffer_queue(struct vb2_buffer *vb)
-{
-	struct skeleton *skel = vb2_get_drv_priv(vb->vb2_queue);
-	struct skel_buffer *buf = to_skel_buffer(vb);
-	unsigned long flags;
-
-	spin_lock_irqsave(&skel->qlock, flags);
-	list_add_tail(&buf->list, &skel->buf_list);
-
-	/* TODO: Update any DMA pointers if necessary */
-
-	spin_unlock_irqrestore(&skel->qlock, flags);
-}
-
-static void return_all_buffers(struct skeleton *skel,
-			       enum vb2_buffer_state state)
-{
-	struct skel_buffer *buf, *node;
-	unsigned long flags;
-
-	spin_lock_irqsave(&skel->qlock, flags);
-	list_for_each_entry_safe(buf, node, &skel->buf_list, list) {
-		vb2_buffer_done(&buf->vb, state);
-		list_del(&buf->list);
-	}
-	spin_unlock_irqrestore(&skel->qlock, flags);
-}
-
-/*
- * Start streaming. First check if the minimum number of buffers have been
- * queued. If not, then return -ENOBUFS and the vb2 framework will call
- * this function again the next time a buffer has been queued until enough
- * buffers are available to actually start the DMA engine.
- */
-static int start_streaming(struct vb2_queue *vq, unsigned int count)
-{
-	struct skeleton *skel = vb2_get_drv_priv(vq);
-	int ret = 0;
-
-	skel->sequence = 0;
-
-	/* TODO: start DMA */
-
-	if (ret) {
-		/*
-		 * In case of an error, return all active buffers to the
-		 * QUEUED state
-		 */
-		return_all_buffers(skel, VB2_BUF_STATE_QUEUED);
-	}
-	return ret;
-}
-
-/*
- * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
- * and passed on to the vb2 framework marked as STATE_ERROR.
- */
-static void stop_streaming(struct vb2_queue *vq)
-{
-	struct skeleton *skel = vb2_get_drv_priv(vq);
-
-	/* TODO: stop DMA */
-
-	/* Release all active buffers */
-	return_all_buffers(skel, VB2_BUF_STATE_ERROR);
-}
-
-/*
- * The vb2 queue ops. Note that since q->lock is set we can use the standard
- * vb2_ops_wait_prepare/finish helper functions. If q->lock would be NULL,
- * then this driver would have to provide these ops.
- */
-static struct vb2_ops skel_qops = {
-	.queue_setup		= queue_setup,
-	.buf_prepare		= buffer_prepare,
-	.buf_queue		= buffer_queue,
-	.start_streaming	= start_streaming,
-	.stop_streaming		= stop_streaming,
-	.wait_prepare		= vb2_ops_wait_prepare,
-	.wait_finish		= vb2_ops_wait_finish,
-};
-
-/*
- * Required ioctl querycap. Note that the version field is prefilled with
- * the version of the kernel.
- */
-static int skeleton_querycap(struct file *file, void *priv,
-			     struct v4l2_capability *cap)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
-	strlcpy(cap->card, "V4L2 PCI Skeleton", sizeof(cap->card));
-	snprintf(cap->bus_info, sizeof(cap->bus_info), "PCI:%s",
-		 pci_name(skel->pdev));
-	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
-			   V4L2_CAP_STREAMING;
-	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
-	return 0;
-}
-
-/*
- * Helper function to check and correct struct v4l2_pix_format. It's used
- * not only in VIDIOC_TRY/S_FMT, but also elsewhere if changes to the SDTV
- * standard, HDTV timings or the video input would require updating the
- * current format.
- */
-static void skeleton_fill_pix_format(struct skeleton *skel,
-				     struct v4l2_pix_format *pix)
-{
-	pix->pixelformat = V4L2_PIX_FMT_YUYV;
-	if (skel->input == 0) {
-		/* S-Video input */
-		pix->width = 720;
-		pix->height = (skel->std & V4L2_STD_525_60) ? 480 : 576;
-		pix->field = V4L2_FIELD_INTERLACED;
-		pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
-	} else {
-		/* HDMI input */
-		pix->width = skel->timings.bt.width;
-		pix->height = skel->timings.bt.height;
-		if (skel->timings.bt.interlaced) {
-			pix->field = V4L2_FIELD_ALTERNATE;
-			pix->height /= 2;
-		} else {
-			pix->field = V4L2_FIELD_NONE;
-		}
-		pix->colorspace = V4L2_COLORSPACE_REC709;
-	}
-
-	/*
-	 * The YUYV format is four bytes for every two pixels, so bytesperline
-	 * is width * 2.
-	 */
-	pix->bytesperline = pix->width * 2;
-	pix->sizeimage = pix->bytesperline * pix->height;
-	pix->priv = 0;
-}
-
-static int skeleton_try_fmt_vid_cap(struct file *file, void *priv,
-				    struct v4l2_format *f)
-{
-	struct skeleton *skel = video_drvdata(file);
-	struct v4l2_pix_format *pix = &f->fmt.pix;
-
-	/*
-	 * Due to historical reasons providing try_fmt with an unsupported
-	 * pixelformat will return -EINVAL for video receivers. Webcam drivers,
-	 * however, will silently correct the pixelformat. Some video capture
-	 * applications rely on this behavior...
-	 */
-	if (pix->pixelformat != V4L2_PIX_FMT_YUYV)
-		return -EINVAL;
-	skeleton_fill_pix_format(skel, pix);
-	return 0;
-}
-
-static int skeleton_s_fmt_vid_cap(struct file *file, void *priv,
-				  struct v4l2_format *f)
-{
-	struct skeleton *skel = video_drvdata(file);
-	int ret;
-
-	ret = skeleton_try_fmt_vid_cap(file, priv, f);
-	if (ret)
-		return ret;
-
-	/*
-	 * It is not allowed to change the format while buffers for use with
-	 * streaming have already been allocated.
-	 */
-	if (vb2_is_busy(&skel->queue))
-		return -EBUSY;
-
-	/* TODO: change format */
-	skel->format = f->fmt.pix;
-	return 0;
-}
-
-static int skeleton_g_fmt_vid_cap(struct file *file, void *priv,
-				  struct v4l2_format *f)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	f->fmt.pix = skel->format;
-	return 0;
-}
-
-static int skeleton_enum_fmt_vid_cap(struct file *file, void *priv,
-				     struct v4l2_fmtdesc *f)
-{
-	if (f->index != 0)
-		return -EINVAL;
-
-	f->pixelformat = V4L2_PIX_FMT_YUYV;
-	return 0;
-}
-
-static int skeleton_s_std(struct file *file, void *priv, v4l2_std_id std)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* S_STD is not supported on the HDMI input */
-	if (skel->input)
-		return -ENODATA;
-
-	/*
-	 * No change, so just return. Some applications call S_STD again after
-	 * the buffers for streaming have been set up, so we have to allow for
-	 * this behavior.
-	 */
-	if (std == skel->std)
-		return 0;
-
-	/*
-	 * Changing the standard implies a format change, which is not allowed
-	 * while buffers for use with streaming have already been allocated.
-	 */
-	if (vb2_is_busy(&skel->queue))
-		return -EBUSY;
-
-	/* TODO: handle changing std */
-
-	skel->std = std;
-
-	/* Update the internal format */
-	skeleton_fill_pix_format(skel, &skel->format);
-	return 0;
-}
-
-static int skeleton_g_std(struct file *file, void *priv, v4l2_std_id *std)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* G_STD is not supported on the HDMI input */
-	if (skel->input)
-		return -ENODATA;
-
-	*std = skel->std;
-	return 0;
-}
-
-/*
- * Query the current standard as seen by the hardware. This function shall
- * never actually change the standard, it just detects and reports.
- * The framework will initially set *std to tvnorms (i.e. the set of
- * supported standards by this input), and this function should just AND
- * this value. If there is no signal, then *std should be set to 0.
- */
-static int skeleton_querystd(struct file *file, void *priv, v4l2_std_id *std)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* QUERY_STD is not supported on the HDMI input */
-	if (skel->input)
-		return -ENODATA;
-
-#ifdef TODO
-	/*
-	 * Query currently seen standard. Initial value of *std is
-	 * V4L2_STD_ALL. This function should look something like this:
-	 */
-	get_signal_info();
-	if (no_signal) {
-		*std = 0;
-		return 0;
-	}
-	/* Use signal information to reduce the number of possible standards */
-	if (signal_has_525_lines)
-		*std &= V4L2_STD_525_60;
-	else
-		*std &= V4L2_STD_625_50;
-#endif
-	return 0;
-}
-
-static int skeleton_s_dv_timings(struct file *file, void *_fh,
-				 struct v4l2_dv_timings *timings)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* S_DV_TIMINGS is not supported on the S-Video input */
-	if (skel->input == 0)
-		return -ENODATA;
-
-	/* Quick sanity check */
-	if (!v4l2_valid_dv_timings(timings, &skel_timings_cap, NULL, NULL))
-		return -EINVAL;
-
-	/* Check if the timings are part of the CEA-861 timings. */
-	if (!v4l2_find_dv_timings_cap(timings, &skel_timings_cap,
-				      0, NULL, NULL))
-		return -EINVAL;
-
-	/* Return 0 if the new timings are the same as the current timings. */
-	if (v4l2_match_dv_timings(timings, &skel->timings, 0, false))
-		return 0;
-
-	/*
-	 * Changing the timings implies a format change, which is not allowed
-	 * while buffers for use with streaming have already been allocated.
-	 */
-	if (vb2_is_busy(&skel->queue))
-		return -EBUSY;
-
-	/* TODO: Configure new timings */
-
-	/* Save timings */
-	skel->timings = *timings;
-
-	/* Update the internal format */
-	skeleton_fill_pix_format(skel, &skel->format);
-	return 0;
-}
-
-static int skeleton_g_dv_timings(struct file *file, void *_fh,
-				 struct v4l2_dv_timings *timings)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* G_DV_TIMINGS is not supported on the S-Video input */
-	if (skel->input == 0)
-		return -ENODATA;
-
-	*timings = skel->timings;
-	return 0;
-}
-
-static int skeleton_enum_dv_timings(struct file *file, void *_fh,
-				    struct v4l2_enum_dv_timings *timings)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* ENUM_DV_TIMINGS is not supported on the S-Video input */
-	if (skel->input == 0)
-		return -ENODATA;
-
-	return v4l2_enum_dv_timings_cap(timings, &skel_timings_cap,
-					NULL, NULL);
-}
-
-/*
- * Query the current timings as seen by the hardware. This function shall
- * never actually change the timings, it just detects and reports.
- * If no signal is detected, then return -ENOLINK. If the hardware cannot
- * lock to the signal, then return -ENOLCK. If the signal is out of range
- * of the capabilities of the system (e.g., it is possible that the receiver
- * can lock but that the DMA engine it is connected to cannot handle
- * pixelclocks above a certain frequency), then -ERANGE is returned.
- */
-static int skeleton_query_dv_timings(struct file *file, void *_fh,
-				     struct v4l2_dv_timings *timings)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* QUERY_DV_TIMINGS is not supported on the S-Video input */
-	if (skel->input == 0)
-		return -ENODATA;
-
-#ifdef TODO
-	/*
-	 * Query currently seen timings. This function should look
-	 * something like this:
-	 */
-	detect_timings();
-	if (no_signal)
-		return -ENOLINK;
-	if (cannot_lock_to_signal)
-		return -ENOLCK;
-	if (signal_out_of_range_of_capabilities)
-		return -ERANGE;
-
-	/* Useful for debugging */
-	v4l2_print_dv_timings(skel->v4l2_dev.name, "query_dv_timings:",
-			timings, true);
-#endif
-	return 0;
-}
-
-static int skeleton_dv_timings_cap(struct file *file, void *fh,
-				   struct v4l2_dv_timings_cap *cap)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	/* DV_TIMINGS_CAP is not supported on the S-Video input */
-	if (skel->input == 0)
-		return -ENODATA;
-	*cap = skel_timings_cap;
-	return 0;
-}
-
-static int skeleton_enum_input(struct file *file, void *priv,
-			       struct v4l2_input *i)
-{
-	if (i->index > 1)
-		return -EINVAL;
-
-	i->type = V4L2_INPUT_TYPE_CAMERA;
-	if (i->index == 0) {
-		i->std = SKEL_TVNORMS;
-		strlcpy(i->name, "S-Video", sizeof(i->name));
-		i->capabilities = V4L2_IN_CAP_STD;
-	} else {
-		i->std = 0;
-		strlcpy(i->name, "HDMI", sizeof(i->name));
-		i->capabilities = V4L2_IN_CAP_DV_TIMINGS;
-	}
-	return 0;
-}
-
-static int skeleton_s_input(struct file *file, void *priv, unsigned int i)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	if (i > 1)
-		return -EINVAL;
-
-	/*
-	 * Changing the input implies a format change, which is not allowed
-	 * while buffers for use with streaming have already been allocated.
-	 */
-	if (vb2_is_busy(&skel->queue))
-		return -EBUSY;
-
-	skel->input = i;
-	/*
-	 * Update tvnorms. The tvnorms value is used by the core to implement
-	 * VIDIOC_ENUMSTD so it has to be correct. If tvnorms == 0, then
-	 * ENUMSTD will return -ENODATA.
-	 */
-	skel->vdev.tvnorms = i ? 0 : SKEL_TVNORMS;
-
-	/* Update the internal format */
-	skeleton_fill_pix_format(skel, &skel->format);
-	return 0;
-}
-
-static int skeleton_g_input(struct file *file, void *priv, unsigned int *i)
-{
-	struct skeleton *skel = video_drvdata(file);
-
-	*i = skel->input;
-	return 0;
-}
-
-/* The control handler. */
-static int skeleton_s_ctrl(struct v4l2_ctrl *ctrl)
-{
-	/*struct skeleton *skel =
-		container_of(ctrl->handler, struct skeleton, ctrl_handler);*/
-
-	switch (ctrl->id) {
-	case V4L2_CID_BRIGHTNESS:
-		/* TODO: set brightness to ctrl->val */
-		break;
-	case V4L2_CID_CONTRAST:
-		/* TODO: set contrast to ctrl->val */
-		break;
-	case V4L2_CID_SATURATION:
-		/* TODO: set saturation to ctrl->val */
-		break;
-	case V4L2_CID_HUE:
-		/* TODO: set hue to ctrl->val */
-		break;
-	default:
-		return -EINVAL;
-	}
-	return 0;
-}
-
-/* ------------------------------------------------------------------
-	File operations for the device
-   ------------------------------------------------------------------*/
-
-static const struct v4l2_ctrl_ops skel_ctrl_ops = {
-	.s_ctrl = skeleton_s_ctrl,
-};
-
-/*
- * The set of all supported ioctls. Note that all the streaming ioctls
- * use the vb2 helper functions that take care of all the locking and
- * that also do ownership tracking (i.e. only the filehandle that requested
- * the buffers can call the streaming ioctls, all other filehandles will
- * receive -EBUSY if they attempt to call the same streaming ioctls).
- *
- * The last three ioctls also use standard helper functions: these implement
- * standard behavior for drivers with controls.
- */
-static const struct v4l2_ioctl_ops skel_ioctl_ops = {
-	.vidioc_querycap = skeleton_querycap,
-	.vidioc_try_fmt_vid_cap = skeleton_try_fmt_vid_cap,
-	.vidioc_s_fmt_vid_cap = skeleton_s_fmt_vid_cap,
-	.vidioc_g_fmt_vid_cap = skeleton_g_fmt_vid_cap,
-	.vidioc_enum_fmt_vid_cap = skeleton_enum_fmt_vid_cap,
-
-	.vidioc_g_std = skeleton_g_std,
-	.vidioc_s_std = skeleton_s_std,
-	.vidioc_querystd = skeleton_querystd,
-
-	.vidioc_s_dv_timings = skeleton_s_dv_timings,
-	.vidioc_g_dv_timings = skeleton_g_dv_timings,
-	.vidioc_enum_dv_timings = skeleton_enum_dv_timings,
-	.vidioc_query_dv_timings = skeleton_query_dv_timings,
-	.vidioc_dv_timings_cap = skeleton_dv_timings_cap,
-
-	.vidioc_enum_input = skeleton_enum_input,
-	.vidioc_g_input = skeleton_g_input,
-	.vidioc_s_input = skeleton_s_input,
-
-	.vidioc_reqbufs = vb2_ioctl_reqbufs,
-	.vidioc_create_bufs = vb2_ioctl_create_bufs,
-	.vidioc_querybuf = vb2_ioctl_querybuf,
-	.vidioc_qbuf = vb2_ioctl_qbuf,
-	.vidioc_dqbuf = vb2_ioctl_dqbuf,
-	.vidioc_expbuf = vb2_ioctl_expbuf,
-	.vidioc_streamon = vb2_ioctl_streamon,
-	.vidioc_streamoff = vb2_ioctl_streamoff,
-
-	.vidioc_log_status = v4l2_ctrl_log_status,
-	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
-	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
-};
-
-/*
- * The set of file operations. Note that all these ops are standard core
- * helper functions.
- */
-static const struct v4l2_file_operations skel_fops = {
-	.owner = THIS_MODULE,
-	.open = v4l2_fh_open,
-	.release = vb2_fop_release,
-	.unlocked_ioctl = video_ioctl2,
-	.read = vb2_fop_read,
-	.mmap = vb2_fop_mmap,
-	.poll = vb2_fop_poll,
-};
-
-/*
- * The initial setup of this device instance. Note that the initial state of
- * the driver should be complete. So the initial format, standard, timings
- * and video input should all be initialized to some reasonable value.
- */
-static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
-{
-	/* The initial timings are chosen to be 720p60. */
-	static const struct v4l2_dv_timings timings_def =
-		V4L2_DV_BT_CEA_1280X720P60;
-	struct skeleton *skel;
-	struct video_device *vdev;
-	struct v4l2_ctrl_handler *hdl;
-	struct vb2_queue *q;
-	int ret;
-
-	/* Enable PCI */
-	ret = pci_enable_device(pdev);
-	if (ret)
-		return ret;
-	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
-	if (ret) {
-		dev_err(&pdev->dev, "no suitable DMA available.\n");
-		goto disable_pci;
-	}
-
-	/* Allocate a new instance */
-	skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL);
-	if (!skel)
-		return -ENOMEM;
-
-	/* Allocate the interrupt */
-	ret = devm_request_irq(&pdev->dev, pdev->irq,
-			       skeleton_irq, 0, KBUILD_MODNAME, skel);
-	if (ret) {
-		dev_err(&pdev->dev, "request_irq failed\n");
-		goto disable_pci;
-	}
-	skel->pdev = pdev;
-
-	/* Fill in the initial format-related settings */
-	skel->timings = timings_def;
-	skel->std = V4L2_STD_625_50;
-	skeleton_fill_pix_format(skel, &skel->format);
-
-	/* Initialize the top-level structure */
-	ret = v4l2_device_register(&pdev->dev, &skel->v4l2_dev);
-	if (ret)
-		goto disable_pci;
-
-	mutex_init(&skel->lock);
-
-	/* Add the controls */
-	hdl = &skel->ctrl_handler;
-	v4l2_ctrl_handler_init(hdl, 4);
-	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
-			  V4L2_CID_BRIGHTNESS, 0, 255, 1, 127);
-	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
-			  V4L2_CID_CONTRAST, 0, 255, 1, 16);
-	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
-			  V4L2_CID_SATURATION, 0, 255, 1, 127);
-	v4l2_ctrl_new_std(hdl, &skel_ctrl_ops,
-			  V4L2_CID_HUE, -128, 127, 1, 0);
-	if (hdl->error) {
-		ret = hdl->error;
-		goto free_hdl;
-	}
-	skel->v4l2_dev.ctrl_handler = hdl;
-
-	/* Initialize the vb2 queue */
-	q = &skel->queue;
-	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-	q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
-	q->drv_priv = skel;
-	q->buf_struct_size = sizeof(struct skel_buffer);
-	q->ops = &skel_qops;
-	q->mem_ops = &vb2_dma_contig_memops;
-	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
-	/*
-	 * Assume that this DMA engine needs to have at least two buffers
-	 * available before it can be started. The start_streaming() op
-	 * won't be called until at least this many buffers are queued up.
-	 */
-	q->min_buffers_needed = 2;
-	/*
-	 * The serialization lock for the streaming ioctls. This is the same
-	 * as the main serialization lock, but if some of the non-streaming
-	 * ioctls could take a long time to execute, then you might want to
-	 * have a different lock here to prevent VIDIOC_DQBUF from being
-	 * blocked while waiting for another action to finish. This is
-	 * generally not needed for PCI devices, but USB devices usually do
-	 * want a separate lock here.
-	 */
-	q->lock = &skel->lock;
-	/*
-	 * Since this driver can only do 32-bit DMA we must make sure that
-	 * the vb2 core will allocate the buffers in 32-bit DMA memory.
-	 */
-	q->gfp_flags = GFP_DMA32;
-	ret = vb2_queue_init(q);
-	if (ret)
-		goto free_hdl;
-
-	skel->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
-	if (IS_ERR(skel->alloc_ctx)) {
-		dev_err(&pdev->dev, "Can't allocate buffer context");
-		ret = PTR_ERR(skel->alloc_ctx);
-		goto free_hdl;
-	}
-	INIT_LIST_HEAD(&skel->buf_list);
-	spin_lock_init(&skel->qlock);
-
-	/* Initialize the video_device structure */
-	vdev = &skel->vdev;
-	strlcpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
-	/*
-	 * There is nothing to clean up, so release is set to an empty release
-	 * function. The release callback must be non-NULL.
-	 */
-	vdev->release = video_device_release_empty;
-	vdev->fops = &skel_fops,
-	vdev->ioctl_ops = &skel_ioctl_ops,
-	/*
-	 * The main serialization lock. All ioctls are serialized by this
-	 * lock. Exception: if q->lock is set, then the streaming ioctls
-	 * are serialized by that separate lock.
-	 */
-	vdev->lock = &skel->lock;
-	vdev->queue = q;
-	vdev->v4l2_dev = &skel->v4l2_dev;
-	/* Supported SDTV standards, if any */
-	vdev->tvnorms = SKEL_TVNORMS;
-	video_set_drvdata(vdev, skel);
-
-	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
-	if (ret)
-		goto free_ctx;
-
-	dev_info(&pdev->dev, "V4L2 PCI Skeleton Driver loaded\n");
-	return 0;
-
-free_ctx:
-	vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
-free_hdl:
-	v4l2_ctrl_handler_free(&skel->ctrl_handler);
-	v4l2_device_unregister(&skel->v4l2_dev);
-disable_pci:
-	pci_disable_device(pdev);
-	return ret;
-}
-
-static void skeleton_remove(struct pci_dev *pdev)
-{
-	struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
-	struct skeleton *skel = container_of(v4l2_dev, struct skeleton, v4l2_dev);
-
-	video_unregister_device(&skel->vdev);
-	v4l2_ctrl_handler_free(&skel->ctrl_handler);
-	vb2_dma_contig_cleanup_ctx(skel->alloc_ctx);
-	v4l2_device_unregister(&skel->v4l2_dev);
-	pci_disable_device(skel->pdev);
-}
-
-static struct pci_driver skeleton_driver = {
-	.name = KBUILD_MODNAME,
-	.probe = skeleton_probe,
-	.remove = skeleton_remove,
-	.id_table = skeleton_pci_tbl,
-};
-
-module_pci_driver(skeleton_driver);