media: ov6650: Fix .get_fmt() V4L2_SUBDEV_FORMAT_TRY support

Commit da298c6d ("[media] v4l2: replace video op g_mbus_fmt by pad
op get_fmt") converted a former ov6650_g_fmt() video operation callback
to an ov6650_get_fmt() pad operation callback.  However, the converted
function disregards a format->which flag that pad operations should
obey and always returns active frame format settings.

That can be fixed by always responding to V4L2_SUBDEV_FORMAT_TRY with
-EINVAL, or providing the response from a pad config argument, likely
updated by a former user call to V4L2_SUBDEV_FORMAT_TRY .set_fmt().
Since implementation of the latter is trivial, go for it.

Fixes: da298c6d ("[media] v4l2: replace video op g_mbus_fmt by pad op get_fmt")
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/i2c/ov6650.c

@@ -525,10 +525,16 @@ static int ov6650_get_fmt(struct v4l2_subdev *sd,
 	*mf = ov6650_def_fmt;
 
 	/* update media bus format code and frame size */
-	mf->width	= priv->rect.width >> priv->half_scale;
-	mf->height	= priv->rect.height >> priv->half_scale;
-	mf->code	= priv->code;
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
+		mf->width = cfg->try_fmt.width;
+		mf->height = cfg->try_fmt.height;
+		mf->code = cfg->try_fmt.code;
 
+	} else {
+		mf->width = priv->rect.width >> priv->half_scale;
+		mf->height = priv->rect.height >> priv->half_scale;
+		mf->code = priv->code;
+	}
 	return 0;
 }