[media] v4l: emulate old crop API using extended crop/compose API

This patch allows new video drivers to work correctly with applications that
use the old-style crop API.  The old crop ioctl is emulated by using selection
callbacks.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/v4l2-ioctl.c

@@ -1549,11 +1549,32 @@ static long __video_do_ioctl(struct file *file,
 	{
 		struct v4l2_crop *p = arg;
 
-		if (!ops->vidioc_g_crop)
+		if (!ops->vidioc_g_crop && !ops->vidioc_g_selection)
 			break;
 
 		dbgarg(cmd, "type=%s\n", prt_names(p->type, v4l2_type_names));
+
+		if (ops->vidioc_g_crop) {
 			ret = ops->vidioc_g_crop(file, fh, p);
+		} else {
+			/* simulate capture crop using selection api */
+			struct v4l2_selection s = {
+				.type = p->type,
+			};
+
+			/* crop means compose for output devices */
+			if (V4L2_TYPE_IS_OUTPUT(p->type))
+				s.target = V4L2_SEL_TGT_COMPOSE_ACTIVE;
+			else
+				s.target = V4L2_SEL_TGT_CROP_ACTIVE;
+
+			ret = ops->vidioc_g_selection(file, fh, &s);
+
+			/* copying results to old structure on success */
+			if (!ret)
+				p->c = s.r;
+		}
+
 		if (!ret)
 			dbgrect(vfd, "", &p->c);
 		break;
@@ -1562,15 +1583,33 @@ static long __video_do_ioctl(struct file *file,
 	{
 		struct v4l2_crop *p = arg;
 
-		if (!ops->vidioc_s_crop)
+		if (!ops->vidioc_s_crop && !ops->vidioc_s_selection)
 			break;
+
 		if (ret_prio) {
 			ret = ret_prio;
 			break;
 		}
 		dbgarg(cmd, "type=%s\n", prt_names(p->type, v4l2_type_names));
 		dbgrect(vfd, "", &p->c);
+
+		if (ops->vidioc_s_crop) {
 			ret = ops->vidioc_s_crop(file, fh, p);
+		} else {
+			/* simulate capture crop using selection api */
+			struct v4l2_selection s = {
+				.type = p->type,
+				.r = p->c,
+			};
+
+			/* crop means compose for output devices */
+			if (V4L2_TYPE_IS_OUTPUT(p->type))
+				s.target = V4L2_SEL_TGT_COMPOSE_ACTIVE;
+			else
+				s.target = V4L2_SEL_TGT_CROP_ACTIVE;
+
+			ret = ops->vidioc_s_selection(file, fh, &s);
+		}
 		break;
 	}
 	case VIDIOC_G_SELECTION:
@@ -1610,11 +1649,42 @@ static long __video_do_ioctl(struct file *file,
 		struct v4l2_cropcap *p = arg;
 
 		/*FIXME: Should also show v4l2_fract pixelaspect */
-		if (!ops->vidioc_cropcap)
+		if (!ops->vidioc_cropcap && !ops->vidioc_g_selection)
 			break;
 
 		dbgarg(cmd, "type=%s\n", prt_names(p->type, v4l2_type_names));
+		if (ops->vidioc_cropcap) {
 			ret = ops->vidioc_cropcap(file, fh, p);
+		} else {
+			struct v4l2_selection s = { .type = p->type };
+
+			/* obtaining bounds */
+			if (V4L2_TYPE_IS_OUTPUT(p->type))
+				s.target = V4L2_SEL_TGT_COMPOSE_BOUNDS;
+			else
+				s.target = V4L2_SEL_TGT_CROP_BOUNDS;
+
+			ret = ops->vidioc_g_selection(file, fh, &s);
+			if (ret)
+				break;
+			p->bounds = s.r;
+
+			/* obtaining defrect */
+			if (V4L2_TYPE_IS_OUTPUT(p->type))
+				s.target = V4L2_SEL_TGT_COMPOSE_DEFAULT;
+			else
+				s.target = V4L2_SEL_TGT_CROP_DEFAULT;
+
+			ret = ops->vidioc_g_selection(file, fh, &s);
+			if (ret)
+				break;
+			p->defrect = s.r;
+
+			/* setting trivial pixelaspect */
+			p->pixelaspect.numerator = 1;
+			p->pixelaspect.denominator = 1;
+		}
+
 		if (!ret) {
 			dbgrect(vfd, "bounds ", &p->bounds);
 			dbgrect(vfd, "defrect ", &p->defrect);