[media] v4l: Support extending the v4l2_pix_format structure

The v4l2_pix_format structure has no reserved field. It is embedded in
the v4l2_framebuffer structure which has no reserved fields either, and
in the v4l2_format structure which has reserved fields that were not
previously required to be zeroed out by applications.

To allow extending v4l2_pix_format, inline it in the v4l2_framebuffer
structure, and use the priv field as a magic value to indicate that the
application has set all v4l2_pix_format extended fields and zeroed all
reserved fields following the v4l2_pix_format field in the v4l2_format
structure.

The availability of this API extension is reported to userspace through
the new V4L2_CAP_EXT_PIX_FORMAT capability flag. Just checking that the
priv field is still set to the magic value at [GS]_FMT return wouldn't
be enough, as older kernels don't zero the priv field on return.

To simplify the internal API towards drivers zero the extended fields
and set the priv field to the magic value for applications not aware of
the extensions.

Signed-off-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Documentation/DocBook/media/Makefile

···
 DOCUMENTED = \
 	-e "s/\(enum *\)v4l2_mpeg_cx2341x_video_\([a-z]*_spatial_filter_type\)/\1<link linkend=\"\2\">v4l2_mpeg_cx2341x_video_\2<\/link>/g" \
 	-e "s/\(\(enum\|struct\) *\)\(v4l2_[a-zA-Z0-9_]*\)/\1<link linkend=\"\3\">\3<\/link>/g" \
-	-e "s/\(V4L2_PIX_FMT_[A-Z0-9_]\+\) /<link linkend=\"\1\">\1<\/link> /g" \
+	-e "s/\(V4L2_PIX_FMT_[A-Z0-9_]\+\)\(\s\+v4l2_fourcc\)/<link linkend=\"\1\">\1<\/link>\2/g" \
 	-e ":a;s/\(linkend=\".*\)_\(.*\">\)/\1-\2/;ta" \
 	-e "s/v4l2\-mpeg\-vbi\-ITV0/v4l2-mpeg-vbi-itv0-1/g"
 

Documentation/DocBook/media/v4l/pixfmt.xml

···
 	<row>
 	  <entry>__u32</entry>
 	  <entry><structfield>priv</structfield></entry>
-	  <entry>Reserved for custom (driver defined) additional
-information about formats. When not used drivers and applications must
-set this field to zero.</entry>
+	  <entry><para>This field indicates whether the remaining fields of the
+<structname>v4l2_pix_format</structname> structure, also called the extended
+fields, are valid. When set to <constant>V4L2_PIX_FMT_PRIV_MAGIC</constant>, it
+indicates that the extended fields have been correctly initialized. When set to
+any other value it indicates that the extended fields contain undefined values.
+</para>
+<para>Applications that wish to use the pixel format extended fields must first
+ensure that the feature is supported by querying the device for the
+<link linkend="querycap"><constant>V4L2_CAP_EXT_PIX_FORMAT</constant></link>
+capability. If the capability isn't set the pixel format extended fields are not
+supported and using the extended fields will lead to undefined results.</para>
+<para>To use the extended fields, applications must set the
+<structfield>priv</structfield> field to
+<constant>V4L2_PIX_FMT_PRIV_MAGIC</constant>, initialize all the extended fields
+and zero the unused bytes of the <structname>v4l2_format</structname>
+<structfield>raw_data</structfield> field.</para>
+<para>When the <structfield>priv</structfield> field isn't set to
+<constant>V4L2_PIX_FMT_PRIV_MAGIC</constant> drivers must act as if all the
+extended fields were set to zero. On return drivers must set the
+<structfield>priv</structfield> field to
+<constant>V4L2_PIX_FMT_PRIV_MAGIC</constant> and all the extended fields to
+applicable values.</para></entry>
 	</row>
       </tbody>
     </tgroup>

Documentation/DocBook/media/v4l/v4l2.xml

···
 applications. -->
 
       <revision>
+	<revnumber>3.16</revnumber>
+	<date>2014-05-27</date>
+	<authorinitials>lp</authorinitials>
+	<revremark>Extended &v4l2-pix-format;.
+	</revremark>
+      </revision>
+
+      <revision>
 	<revnumber>3.15</revnumber>
 	<date>2014-02-03</date>
 	<authorinitials>hv, ap</authorinitials>

Documentation/DocBook/media/v4l/vidioc-g-fbuf.xml

···
 framebuffer device (see <xref linkend="osd" />).</entry>
 	  </row>
 	  <row>
-	    <entry>&v4l2-pix-format;</entry>
+	    <entry>struct</entry>
 	    <entry><structfield>fmt</structfield></entry>
 	    <entry></entry>
-	    <entry>Layout of the frame buffer. The
-<structname>v4l2_pix_format</structname> structure is defined in <xref
-linkend="pixfmt" />, for clarification the fields and acceptable values
-	    are listed below:</entry>
+	    <entry>Layout of the frame buffer.</entry>
 	  </row>
 	  <row>
 	    <entry></entry>
···
 	    <entry></entry>
 	    <entry>__u32</entry>
 	    <entry><structfield>priv</structfield></entry>
-	    <entry>Reserved for additional information about custom
-(driver defined) formats. When not used drivers and applications must
-set this field to zero.</entry>
+	    <entry>Reserved. Drivers and applications must set this field to
+zero.</entry>
 	  </row>
 	</tbody>
       </tgroup>

Documentation/DocBook/media/v4l/vidioc-querycap.xml

···
 <link linkend="sdr">SDR Capture</link> interface.</entry>
 	  </row>
 	  <row>
+	    <entry><constant>V4L2_CAP_EXT_PIX_FORMAT</constant></entry>
+	    <entry>0x00200000</entry>
+	    <entry>The device supports the &v4l2-pix-format; extended
+fields.</entry>
+	  </row>
+	  <row>
 	    <entry><constant>V4L2_CAP_READWRITE</constant></entry>
 	    <entry>0x01000000</entry>
 	    <entry>The device supports the <link

drivers/media/parport/bw-qcam.c

···
 	pix->sizeimage = pix->width * pix->height;
 	/* Just a guess */
 	pix->colorspace = V4L2_COLORSPACE_SRGB;
-	pix->priv = 0;
 	return 0;
 }
 
···
 	pix->sizeimage = pix->width * pix->height;
 	/* Just a guess */
 	pix->colorspace = V4L2_COLORSPACE_SRGB;
-	pix->priv = 0;
 	return 0;
 }
 

drivers/media/pci/cx18/cx18-ioctl.c

···
 	pixfmt->height = cx->cxhdl.height;
 	pixfmt->colorspace = V4L2_COLORSPACE_SMPTE170M;
 	pixfmt->field = V4L2_FIELD_INTERLACED;
-	pixfmt->priv = 0;
 	if (id->type == CX18_ENC_STREAM_TYPE_YUV) {
 		pixfmt->pixelformat = s->pixelformat;
 		pixfmt->sizeimage = s->vb_bytes_per_frame;

drivers/media/pci/cx25821/cx25821-video.c

···
 	f->fmt.pix.bytesperline = (chan->width * chan->fmt->depth) >> 3;
 	f->fmt.pix.sizeimage = chan->height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 	return 0;
 }
 

drivers/media/pci/ivtv/ivtv-ioctl.c

···
 	pixfmt->height = itv->cxhdl.height;
 	pixfmt->colorspace = V4L2_COLORSPACE_SMPTE170M;
 	pixfmt->field = V4L2_FIELD_INTERLACED;
-	pixfmt->priv = 0;
 	if (id->type == IVTV_ENC_STREAM_TYPE_YUV) {
 		pixfmt->pixelformat = V4L2_PIX_FMT_HM12;
 		/* YUV size is (Y=(h*720) + UV=(h*(720/2))) */
···
 	pixfmt->height = itv->main_rect.height;
 	pixfmt->colorspace = V4L2_COLORSPACE_SMPTE170M;
 	pixfmt->field = V4L2_FIELD_INTERLACED;
-	pixfmt->priv = 0;
 	if (id->type == IVTV_DEC_STREAM_TYPE_YUV) {
 		switch (itv->yuv_info.lace_mode & IVTV_YUV_MODE_MASK) {
 		case IVTV_YUV_MODE_INTERLACED:
···
 	fb->fmt.bytesperline = fb->fmt.width;
 	fb->fmt.colorspace = V4L2_COLORSPACE_SMPTE170M;
 	fb->fmt.field = V4L2_FIELD_INTERLACED;
-	fb->fmt.priv = 0;
 	if (fb->fmt.pixelformat != V4L2_PIX_FMT_PAL8)
 		fb->fmt.bytesperline *= 2;
 	if (fb->fmt.pixelformat == V4L2_PIX_FMT_RGB32 ||

drivers/media/pci/meye/meye.c

···
 	f->fmt.pix.sizeimage = f->fmt.pix.height *
 			       f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = 0;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.sizeimage = f->fmt.pix.height *
 			       f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = 0;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }

drivers/media/pci/saa7134/saa7134-empress.c

···
 	f->fmt.pix.pixelformat  = V4L2_PIX_FMT_MPEG;
 	f->fmt.pix.sizeimage    = TS_PACKET_SIZE * dev->ts.nr_packets;
 	f->fmt.pix.bytesperline = 0;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.pixelformat  = V4L2_PIX_FMT_MPEG;
 	f->fmt.pix.sizeimage    = TS_PACKET_SIZE * dev->ts.nr_packets;
 	f->fmt.pix.bytesperline = 0;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.pixelformat  = V4L2_PIX_FMT_MPEG;
 	f->fmt.pix.sizeimage    = TS_PACKET_SIZE * dev->ts.nr_packets;
 	f->fmt.pix.bytesperline = 0;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }

drivers/media/pci/saa7134/saa7134-video.c

···
 	f->fmt.pix.sizeimage =
 		f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace   = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 	return 0;
 }
 
···
 	f->fmt.pix.sizeimage =
 		f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace   = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }

drivers/media/pci/sta2x11/sta2x11_vip.c

···
 	f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
 	f->fmt.pix.sizeimage = f->fmt.pix.width * 2 * f->fmt.pix.height;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 	return 0;
 }
 

drivers/media/platform/coda.c

···
 		BUG();
 	}
 
-	f->fmt.pix.priv = 0;
-
 	return 0;
 }
 

drivers/media/platform/davinci/vpif_display.c

···
 	pixfmt->width = common->fmt.fmt.pix.width;
 	pixfmt->height = common->fmt.fmt.pix.height;
 	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height * 2;
-	pixfmt->priv = 0;
 
 	return 0;
 }

drivers/media/platform/mem2mem_testdev.c

···
 	f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.field = V4L2_FIELD_NONE;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }

drivers/media/platform/omap/omap_vout.c

···
 
 	pix->pixelformat = omap_formats[ifmt].pixelformat;
 	pix->field = V4L2_FIELD_ANY;
-	pix->priv = 0;
 
 	switch (pix->pixelformat) {
 	case V4L2_PIX_FMT_YUYV:
···
 	pix->field = V4L2_FIELD_ANY;
 	pix->bytesperline = pix->width * 2;
 	pix->sizeimage = pix->bytesperline * pix->height;
-	pix->priv = 0;
 	pix->colorspace = V4L2_COLORSPACE_JPEG;
 
 	vout->bpp = RGB565_BPP;

drivers/media/platform/sh_veu.c

···
 	pix->bytesperline	= vfmt->bytesperline;
 	pix->sizeimage		= vfmt->bytesperline * pix->height *
 		vfmt->fmt->depth / vfmt->fmt->ydepth;
-	pix->priv		= 0;
 	dev_dbg(veu->dev, "%s(): type: %d, size %u @ %ux%u, fmt %x\n", __func__,
 		f->type, pix->sizeimage, pix->width, pix->height, pix->pixelformat);
 
···
 
 	pix->pixelformat	= fmt->fourcc;
 	pix->colorspace		= sh_veu_4cc2cspace(pix->pixelformat);
-	pix->priv		= 0;
 
 	pr_debug("%s(): type: %d, size %u\n", __func__, f->type, pix->sizeimage);
 

drivers/media/platform/vino.c

···
 	pf->colorspace =
 		vino_data_formats[tempvcs.data_format].colorspace;
 
-	pf->priv = 0;
 	return 0;
 }
 
···
 		vcs->decimation;
 	pf->colorspace =
 		vino_data_formats[vcs->data_format].colorspace;
-
-	pf->priv = 0;
 
 	spin_unlock_irqrestore(&vino_drvdata->input_lock, flags);
 	return 0;
···
 		vcs->decimation;
 	pf->colorspace =
 		vino_data_formats[vcs->data_format].colorspace;
-
-	pf->priv = 0;
 
 	spin_unlock_irqrestore(&vino_drvdata->input_lock, flags);
 	return 0;

drivers/media/platform/vivi.c

···
 		f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 	else
 		f->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
-	f->fmt.pix.priv = 0;
 	return 0;
 }
 

drivers/media/usb/cx231xx/cx231xx-417.c

···
 	f->fmt.pix.width = dev->ts1.width;
 	f->fmt.pix.height = dev->ts1.height;
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
-	f->fmt.pix.priv = 0;
 	dprintk(1, "VIDIOC_G_FMT: w: %d, h: %d\n",
 		dev->ts1.width, dev->ts1.height);
 	dprintk(3, "exit vidioc_g_fmt_vid_cap()\n");
···
 	f->fmt.pix.sizeimage = mpeglines * mpeglinesize;
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
-	f->fmt.pix.priv = 0;
 	dprintk(1, "VIDIOC_TRY_FMT: w: %d, h: %d\n",
 		dev->ts1.width, dev->ts1.height);
 	dprintk(3, "exit vidioc_try_fmt_vid_cap()\n");

drivers/media/usb/cx231xx/cx231xx-video.c

···
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.sizeimage = f->fmt.pix.bytesperline * height;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }

drivers/media/usb/gspca/gspca.c

···
 	struct gspca_dev *gspca_dev = video_drvdata(file);
 
 	fmt->fmt.pix = gspca_dev->pixfmt;
-	/* some drivers use priv internally, zero it before giving it to
-	   userspace */
+	/* some drivers use priv internally, zero it before giving it back to
+	   the core */
 	fmt->fmt.pix.priv = 0;
 	return 0;
 }
···
 		fmt->fmt.pix.height = h;
 		gspca_dev->sd_desc->try_fmt(gspca_dev, fmt);
 	}
-	/* some drivers use priv internally, zero it before giving it to
-	   userspace */
+	/* some drivers use priv internally, zero it before giving it back to
+	   the core */
 	fmt->fmt.pix.priv = 0;
 	return mode;			/* used when s_fmt */
 }

drivers/media/usb/hdpvr/hdpvr-video.c

···
 	f->fmt.pix.pixelformat	= V4L2_PIX_FMT_MPEG;
 	f->fmt.pix.sizeimage	= dev->bulk_in_size;
 	f->fmt.pix.bytesperline	= 0;
-	f->fmt.pix.priv		= 0;
 	if (f->fmt.pix.width == 720) {
 		/* SDTV formats */
 		f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;

drivers/media/usb/stkwebcam/stk-webcam.c

···
 		pix_format->bytesperline = 2 * pix_format->width;
 	pix_format->sizeimage = pix_format->bytesperline
 				* pix_format->height;
-	pix_format->priv = 0;
 	return 0;
 }
 
···
 		fmtd->fmt.pix.bytesperline = 2 * fmtd->fmt.pix.width;
 	fmtd->fmt.pix.sizeimage = fmtd->fmt.pix.bytesperline
 		* fmtd->fmt.pix.height;
-	fmtd->fmt.pix.priv = 0;
 	return 0;
 }
 

drivers/media/usb/tlg2300/pd-video.c

···
 				.bytesperline	= 720 * 2,
 				.sizeimage	= 720 * 576 * 2,
 				.colorspace	= V4L2_COLORSPACE_SMPTE170M,
-				.priv		= 0
 			};
 }
 

drivers/media/usb/tm6000/tm6000-video.c

···
 		(f->fmt.pix.width * fh->fmt->depth) >> 3;
 	f->fmt.pix.sizeimage =
 		f->fmt.pix.height * f->fmt.pix.bytesperline;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
···
 	f->fmt.pix.width &= ~0x01;
 
 	f->fmt.pix.field = field;
-	f->fmt.pix.priv = 0;
 
 	f->fmt.pix.bytesperline =
 		(f->fmt.pix.width * fmt->depth) >> 3;

drivers/media/usb/zr364xx/zr364xx.c

···
 	f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
-	f->fmt.pix.priv = 0;
 	DBG("%s: V4L2_PIX_FMT_%s (%d) ok!\n", __func__,
 	    decode_fourcc(f->fmt.pix.pixelformat, pixelformat_name),
 	    f->fmt.pix.field);
···
 	f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
-	f->fmt.pix.priv = 0;
 	return 0;
 }
 
···
 	f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
 	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
-	f->fmt.pix.priv = 0;
 	cam->vb_vidq.field = f->fmt.pix.field;
 
 	if (f->fmt.pix.width == 160 && f->fmt.pix.height == 120)

drivers/media/v4l2-core/v4l2-compat-ioctl32.c

···
 	__u32			capability;
 	__u32			flags;
 	compat_caddr_t 		base;
-	struct v4l2_pix_format	fmt;
+	struct {
+		__u32		width;
+		__u32		height;
+		__u32		pixelformat;
+		__u32		field;
+		__u32		bytesperline;
+		__u32		sizeimage;
+		__u32		colorspace;
+		__u32		priv;
+	} fmt;
 };
 
 static int get_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_framebuffer32 __user *up)
···
 	if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_framebuffer32)) ||
 		get_user(tmp, &up->base) ||
 		get_user(kp->capability, &up->capability) ||
-		get_user(kp->flags, &up->flags))
+		get_user(kp->flags, &up->flags) ||
+		copy_from_user(&kp->fmt, &up->fmt, sizeof(up->fmt)))
 			return -EFAULT;
 	kp->base = compat_ptr(tmp);
-	get_v4l2_pix_format(&kp->fmt, &up->fmt);
 	return 0;
 }
 
···
 	if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_framebuffer32)) ||
 		put_user(tmp, &up->base) ||
 		put_user(kp->capability, &up->capability) ||
-		put_user(kp->flags, &up->flags))
+		put_user(kp->flags, &up->flags) ||
+		copy_to_user(&up->fmt, &kp->fmt, sizeof(up->fmt)))
 			return -EFAULT;
-	put_v4l2_pix_format(&kp->fmt, &up->fmt);
 	return 0;
 }
 

drivers/media/v4l2-core/v4l2-ioctl.c

···
 	return -EINVAL;
 }
 
+static void v4l_sanitize_format(struct v4l2_format *fmt)
+{
+	unsigned int offset;
+
+	/*
+	 * The v4l2_pix_format structure has been extended with fields that were
+	 * not previously required to be set to zero by applications. The priv
+	 * field, when set to a magic value, indicates the the extended fields
+	 * are valid. Otherwise they will contain undefined values. To simplify
+	 * the API towards drivers zero the extended fields and set the priv
+	 * field to the magic value when the extended pixel format structure
+	 * isn't used by applications.
+	 */
+
+	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
+	    fmt->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
+		return;
+
+	if (fmt->fmt.pix.priv == V4L2_PIX_FMT_PRIV_MAGIC)
+		return;
+
+	fmt->fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
+
+	offset = offsetof(struct v4l2_pix_format, priv)
+	       + sizeof(fmt->fmt.pix.priv);
+	memset(((void *)&fmt->fmt.pix) + offset, 0,
+	       sizeof(fmt->fmt.pix) - offset);
+}
+
 static int v4l_querycap(const struct v4l2_ioctl_ops *ops,
 				struct file *file, void *fh, void *arg)
 {
 	struct v4l2_capability *cap = (struct v4l2_capability *)arg;
+	int ret;
 
 	cap->version = LINUX_VERSION_CODE;
-	return ops->vidioc_querycap(file, fh, cap);
+
+	ret = ops->vidioc_querycap(file, fh, cap);
+
+	cap->capabilities |= V4L2_CAP_EXT_PIX_FORMAT;
+
+	return ret;
 }
 
 static int v4l_s_input(const struct v4l2_ioctl_ops *ops,
···
 	bool is_sdr = vfd->vfl_type == VFL_TYPE_SDR;
 	bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
+	int ret;
+
+	p->fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
 
 	switch (p->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 		if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_vid_cap))
 			break;
-		return ops->vidioc_g_fmt_vid_cap(file, fh, arg);
+		ret = ops->vidioc_g_fmt_vid_cap(file, fh, arg);
+		p->fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
+		return ret;
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
 		if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_vid_cap_mplane))
 			break;
···
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
 		if (unlikely(!is_tx || !is_vid || !ops->vidioc_g_fmt_vid_out))
 			break;
-		return ops->vidioc_g_fmt_vid_out(file, fh, arg);
+		ret = ops->vidioc_g_fmt_vid_out(file, fh, arg);
+		p->fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
+		return ret;
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
 		if (unlikely(!is_tx || !is_vid || !ops->vidioc_g_fmt_vid_out_mplane))
 			break;
···
 	bool is_sdr = vfd->vfl_type == VFL_TYPE_SDR;
 	bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
+
+	v4l_sanitize_format(p);
 
 	switch (p->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
···
 	bool is_sdr = vfd->vfl_type == VFL_TYPE_SDR;
 	bool is_rx = vfd->vfl_dir != VFL_DIR_TX;
 	bool is_tx = vfd->vfl_dir != VFL_DIR_RX;
+
+	v4l_sanitize_format(p);
 
 	switch (p->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
···
 	struct v4l2_create_buffers *create = arg;
 	int ret = check_fmt(file, create->format.type);
 
-	return ret ? ret : ops->vidioc_create_bufs(file, fh, create);
+	if (ret)
+		return ret;
+
+	v4l_sanitize_format(&create->format);
+
+	ret = ops->vidioc_create_bufs(file, fh, create);
+
+	if (create->format.type == V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+	    create->format.type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+		create->format.fmt.pix.priv = V4L2_PIX_FMT_PRIV_MAGIC;
+
+	return ret;
 }
 
 static int v4l_prepare_buf(const struct v4l2_ioctl_ops *ops,

include/uapi/linux/videodev2.h

···
 #define V4L2_CAP_MODULATOR		0x00080000  /* has a modulator */
 
 #define V4L2_CAP_SDR_CAPTURE		0x00100000  /* Is a SDR capture device */
+#define V4L2_CAP_EXT_PIX_FORMAT		0x00200000  /* Supports the extended pixel format */
 
 #define V4L2_CAP_READWRITE              0x01000000  /* read/write systemcalls */
 #define V4L2_CAP_ASYNCIO                0x02000000  /* async I/O */
···
 /* SDR formats - used only for Software Defined Radio devices */
 #define V4L2_SDR_FMT_CU8          v4l2_fourcc('C', 'U', '0', '8') /* IQ u8 */
 #define V4L2_SDR_FMT_CU16LE       v4l2_fourcc('C', 'U', '1', '6') /* IQ u16le */
+
+/* priv field value to indicates that subsequent fields are valid. */
+#define V4L2_PIX_FMT_PRIV_MAGIC		0xfeedcafe
 
 /*
  *	F O R M A T   E N U M E R A T I O N
···
 /* FIXME: in theory we should pass something like PCI device + memory
  * region + offset instead of some physical address */
 	void                    *base;
-	struct v4l2_pix_format	fmt;
+	struct {
+		__u32		width;
+		__u32		height;
+		__u32		pixelformat;
+		__u32		field;		/* enum v4l2_field */
+		__u32		bytesperline;	/* for padding, zero if unused */
+		__u32		sizeimage;
+		__u32		colorspace;	/* enum v4l2_colorspace */
+		__u32		priv;		/* reserved field, set to 0 */
+	} fmt;
 };
 /*  Flags for the 'capability' field. Read only */
 #define V4L2_FBUF_CAP_EXTERNOVERLAY	0x0001