drm: rcar-du: vsp: Extract framebuffer (un)mapping to separate functions

The rcar_du_vsp_plane_prepare_fb() and rcar_du_vsp_plane_cleanup_fb()
functions implement the DRM plane .prepare_fb() and .cleanup_fb()
operations. They map and unmap the framebuffer to/from the VSP
internally, which will be useful to implement writeback support. Split
the mapping and unmapping out to separate functions.

Signed-off-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Kieran Bingham <[e-mail]>

drivers/gpu/drm/rcar-du/rcar_du_vsp.c

···
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
···
 			      plane->index, &cfg);
 }
 
-static int rcar_du_vsp_plane_prepare_fb(struct drm_plane *plane,
-					struct drm_plane_state *state)
+int rcar_du_vsp_map_fb(struct rcar_du_vsp *vsp, struct drm_framebuffer *fb,
+		       struct sg_table sg_tables[3])
 {
-	struct rcar_du_vsp_plane_state *rstate = to_rcar_vsp_plane_state(state);
-	struct rcar_du_vsp *vsp = to_rcar_vsp_plane(plane)->vsp;
 	struct rcar_du_device *rcdu = vsp->dev;
 	unsigned int i;
 	int ret;
 
-	/*
-	 * There's no need to prepare (and unprepare) the framebuffer when the
-	 * plane is not visible, as it will not be displayed.
-	 */
-	if (!state->visible)
-		return 0;
-
-	for (i = 0; i < rstate->format->planes; ++i) {
-		struct drm_gem_cma_object *gem =
-			drm_fb_cma_get_gem_obj(state->fb, i);
-		struct sg_table *sgt = &rstate->sg_tables[i];
+	for (i = 0; i < fb->format->num_planes; ++i) {
+		struct drm_gem_cma_object *gem = drm_fb_cma_get_gem_obj(fb, i);
+		struct sg_table *sgt = &sg_tables[i];
 
 		ret = dma_get_sgtable(rcdu->dev, sgt, gem->vaddr, gem->paddr,
 				      gem->base.size);
···
 		}
 	}
 
-	ret = drm_gem_fb_prepare_fb(plane, state);
-	if (ret)
-		goto fail;
-
 	return 0;
 
 fail:
 	while (i--) {
-		struct sg_table *sgt = &rstate->sg_tables[i];
+		struct sg_table *sgt = &sg_tables[i];
 
 		vsp1_du_unmap_sg(vsp->vsp, sgt);
 		sg_free_table(sgt);
···
 	return ret;
 }
 
+static int rcar_du_vsp_plane_prepare_fb(struct drm_plane *plane,
+					struct drm_plane_state *state)
+{
+	struct rcar_du_vsp_plane_state *rstate = to_rcar_vsp_plane_state(state);
+	struct rcar_du_vsp *vsp = to_rcar_vsp_plane(plane)->vsp;
+	int ret;
+
+	/*
+	 * There's no need to prepare (and unprepare) the framebuffer when the
+	 * plane is not visible, as it will not be displayed.
+	 */
+	if (!state->visible)
+		return 0;
+
+	ret = rcar_du_vsp_map_fb(vsp, state->fb, rstate->sg_tables);
+	if (ret < 0)
+		return ret;
+
+	return drm_gem_fb_prepare_fb(plane, state);
+}
+
+void rcar_du_vsp_unmap_fb(struct rcar_du_vsp *vsp, struct drm_framebuffer *fb,
+			  struct sg_table sg_tables[3])
+{
+	unsigned int i;
+
+	for (i = 0; i < fb->format->num_planes; ++i) {
+		struct sg_table *sgt = &sg_tables[i];
+
+		vsp1_du_unmap_sg(vsp->vsp, sgt);
+		sg_free_table(sgt);
+	}
+}
+
 static void rcar_du_vsp_plane_cleanup_fb(struct drm_plane *plane,
 					 struct drm_plane_state *state)
 {
 	struct rcar_du_vsp_plane_state *rstate = to_rcar_vsp_plane_state(state);
 	struct rcar_du_vsp *vsp = to_rcar_vsp_plane(plane)->vsp;
-	unsigned int i;
 
 	if (!state->visible)
 		return;
 
-	for (i = 0; i < rstate->format->planes; ++i) {
-		struct sg_table *sgt = &rstate->sg_tables[i];
-
-		vsp1_du_unmap_sg(vsp->vsp, sgt);
-		sg_free_table(sgt);
-	}
+	rcar_du_vsp_unmap_fb(vsp, state->fb, rstate->sg_tables);
 }
 
 static int rcar_du_vsp_plane_atomic_check(struct drm_plane *plane,

drivers/gpu/drm/rcar-du/rcar_du_vsp.h

···
 
 #include <drm/drm_plane.h>
 
+struct drm_framebuffer;
 struct rcar_du_format_info;
 struct rcar_du_vsp;
+struct sg_table;
 
 struct rcar_du_vsp_plane {
 	struct drm_plane plane;
···
 void rcar_du_vsp_disable(struct rcar_du_crtc *crtc);
 void rcar_du_vsp_atomic_begin(struct rcar_du_crtc *crtc);
 void rcar_du_vsp_atomic_flush(struct rcar_du_crtc *crtc);
+int rcar_du_vsp_map_fb(struct rcar_du_vsp *vsp, struct drm_framebuffer *fb,
+		       struct sg_table sg_tables[3]);
+void rcar_du_vsp_unmap_fb(struct rcar_du_vsp *vsp, struct drm_framebuffer *fb,
+			  struct sg_table sg_tables[3]);
 #else
 static inline int rcar_du_vsp_init(struct rcar_du_vsp *vsp,
 				   struct device_node *np,
···
 static inline void rcar_du_vsp_disable(struct rcar_du_crtc *crtc) { };
 static inline void rcar_du_vsp_atomic_begin(struct rcar_du_crtc *crtc) { };
 static inline void rcar_du_vsp_atomic_flush(struct rcar_du_crtc *crtc) { };
+static inline int rcar_du_vsp_map_fb(struct rcar_du_vsp *vsp,
+				     struct drm_framebuffer *fb,
+				     struct sg_table sg_tables[3])
+{
+	return -ENXIO;
+}
+static inline void rcar_du_vsp_unmap_fb(struct rcar_du_vsp *vsp,
+					struct drm_framebuffer *fb,
+					struct sg_table sg_tables[3])
+{
+}
 #endif
 
 #endif /* __RCAR_DU_VSP_H__ */