drm/imx: Use drm_mode_get_hv_timing() to populate plane clip rectangle

Use drm_mode_get_hv_timing() to fill out the plane clip rectangle.

Note that this replaces crtc_state->adjusted_mode usage with
crtc_state->mode. The latter is the correct choice since that's the
mode the user provided and it matches the plane crtc coordinates
the user also provided.

Once everyone agrees on this we can move the clip handling into
drm_atomic_helper_check_plane_state().

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171123190502.28449-7-ville.syrjala@linux.intel.com
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -351,7 +351,7 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
 	struct drm_framebuffer *old_fb = old_state->fb;
 	unsigned long eba, ubo, vbo, old_ubo, old_vbo, alpha_eba;
 	bool can_position = (plane->type == DRM_PLANE_TYPE_OVERLAY);
-	struct drm_rect clip;
+	struct drm_rect clip = {};
 	int hsub, vsub;
 	int ret;
 
@@ -367,10 +367,10 @@ static int ipu_plane_atomic_check(struct drm_plane *plane,
 	if (WARN_ON(!crtc_state))
 		return -EINVAL;
 
-	clip.x1 = 0;
-	clip.y1 = 0;
-	clip.x2 = crtc_state->adjusted_mode.hdisplay;
-	clip.y2 = crtc_state->adjusted_mode.vdisplay;
+	if (crtc_state->enable)
+		drm_mode_get_hv_timing(&crtc_state->mode,
+				       &clip.x2, &clip.y2);
+
 	ret = drm_atomic_helper_check_plane_state(state, crtc_state, &clip,
 						  DRM_PLANE_HELPER_NO_SCALING,
 						  DRM_PLANE_HELPER_NO_SCALING,