[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 <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

8 files changed, 4 insertions, 17 deletions

diff --git a/drivers/media/usb/cx231xx/cx231xx-417.c b/drivers/media/usb/cx231xx/cx231xx-417.c
index f0400e260eb7..459bb0e98971 100644
--- a/drivers/media/usb/cx231xx/cx231xx-417.c
+++ b/drivers/media/usb/cx231xx/cx231xx-417.c
@@ -1563,7 +1563,6 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
 	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");
@@ -1582,7 +1581,6 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 	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");
diff --git a/drivers/media/usb/cx231xx/cx231xx-video.c b/drivers/media/usb/cx231xx/cx231xx-video.c
index ae31ca2fc9a1..3b3ada6562ca 100644
--- a/drivers/media/usb/cx231xx/cx231xx-video.c
+++ b/drivers/media/usb/cx231xx/cx231xx-video.c
@@ -885,7 +885,6 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
-	f->fmt.pix.priv = 0;
 
 	return 0;
 }
@@ -930,7 +929,6 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 	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;
 }
diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c
index 42d223239206..e8cf23c91cef 100644
--- a/drivers/media/usb/gspca/gspca.c
+++ b/drivers/media/usb/gspca/gspca.c
@@ -1109,8 +1109,8 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
 	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;
 }
@@ -1146,8 +1146,8 @@ static int try_fmt_vid_cap(struct gspca_dev *gspca_dev,
 		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 */
 }
diff --git a/drivers/media/usb/hdpvr/hdpvr-video.c b/drivers/media/usb/hdpvr/hdpvr-video.c
index dca4b65053aa..4b7653fd4b0b 100644
--- a/drivers/media/usb/hdpvr/hdpvr-video.c
+++ b/drivers/media/usb/hdpvr/hdpvr-video.c
@@ -1022,7 +1022,6 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *_fh,
 	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;
diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index d76860b6a0b8..3588dc38db87 100644
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -923,7 +923,6 @@ static int stk_vidioc_g_fmt_vid_cap(struct file *filp,
 		pix_format->bytesperline = 2 * pix_format->width;
 	pix_format->sizeimage = pix_format->bytesperline
 				* pix_format->height;
-	pix_format->priv = 0;
 	return 0;
 }
 
@@ -967,7 +966,6 @@ static int stk_try_fmt_vid_cap(struct file *filp,
 		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;
 }
 
diff --git a/drivers/media/usb/tlg2300/pd-video.c b/drivers/media/usb/tlg2300/pd-video.c
index 8df668d06552..8cd7f02fcf9f 100644
--- a/drivers/media/usb/tlg2300/pd-video.c
+++ b/drivers/media/usb/tlg2300/pd-video.c
@@ -1321,7 +1321,6 @@ static void init_video_context(struct running_context *context)
 				.bytesperline	= 720 * 2,
 				.sizeimage	= 720 * 576 * 2,
 				.colorspace	= V4L2_COLORSPACE_SMPTE170M,
-				.priv		= 0
 			};
 }
 
diff --git a/drivers/media/usb/tm6000/tm6000-video.c b/drivers/media/usb/tm6000/tm6000-video.c
index 9bde0642ffd1..793577fc4633 100644
--- a/drivers/media/usb/tm6000/tm6000-video.c
+++ b/drivers/media/usb/tm6000/tm6000-video.c
@@ -918,7 +918,6 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
 		(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;
 }
@@ -959,7 +958,6 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 	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;
diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c
index 3b80579a82c5..5c006277b8b1 100644
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -806,7 +806,6 @@ static int zr364xx_vidioc_try_fmt_vid_cap(struct file *file, void *priv,
 	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);
@@ -829,7 +828,6 @@ static int zr364xx_vidioc_g_fmt_vid_cap(struct file *file, void *priv,
 	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;
 }
 
@@ -866,7 +864,6 @@ static int zr364xx_vidioc_s_fmt_vid_cap(struct file *file, void *priv,
 	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)