drm/sun4i: Drop hardcoded .possible_crtcs values from layers

To support multiple display pipelines, we would have multiple crtcs,
with one or more planes bound to them. Obviously having hardcoded
values for the drm_plane .possible_crtcs field is not going to work.

For primary and cursor planes, the value is set by
drm_crtc_init_with_planes. We just need to set it for overlay planes.

We also fix the value set for the RGB encoder, by referencing the
crtc set in sun4i_drv.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_crtc.c

@@ -190,5 +190,14 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm)
 	scrtc->crtc.port = of_graph_get_port_by_id(drv->tcon->dev->of_node,
 						   1);
 
+	/* Set possible_crtcs to this crtc for overlay planes */
+	for (i = 0; scrtc->layers[i]; i++) {
+		uint32_t possible_crtcs = BIT(drm_crtc_index(&scrtc->crtc));
+		struct sun4i_layer *layer = scrtc->layers[i];
+
+		if (layer->plane.type == DRM_PLANE_TYPE_OVERLAY)
+			layer->plane.possible_crtcs = possible_crtcs;
+	}
+
 	return scrtc;
 }

drivers/gpu/drm/sun4i/sun4i_layer.c

@@ -114,7 +114,8 @@ static struct sun4i_layer *sun4i_layer_init_one(struct drm_device *drm,
 	if (!layer)
 		return ERR_PTR(-ENOMEM);
 
-	ret = drm_universal_plane_init(drm, &layer->plane, BIT(0),
+	/* possible crtcs are set later */
+	ret = drm_universal_plane_init(drm, &layer->plane, 0,
 				       &sun4i_backend_layer_funcs,
 				       plane->formats, plane->nformats,
 				       plane->type, NULL);

drivers/gpu/drm/sun4i/sun4i_rgb.c

@@ -17,6 +17,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_panel.h>
 
+#include "sun4i_crtc.h"
 #include "sun4i_drv.h"
 #include "sun4i_tcon.h"
 #include "sun4i_rgb.h"
@@ -238,7 +239,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 	}
 
 	/* The RGB encoder can only work with the TCON channel 0 */
-	rgb->encoder.possible_crtcs = BIT(0);
+	rgb->encoder.possible_crtcs = BIT(drm_crtc_index(&tcon->crtc->crtc));
 
 	if (!IS_ERR(tcon->panel)) {
 		drm_connector_helper_add(&rgb->connector,