drm/sun4i: abstract a engine type

As we are going to add support for the Allwinner DE2 engine in sun4i-drm
driver, we will finally have two types of display engines -- the DE1
backend and the DE2 mixer. They both do some display blending and feed
graphics data to TCON, and is part of the "Display Engine" called by
Allwinner, so I choose to call them both "engine" here.

Abstract the engine type to a new struct with an ops struct, which contains
functions that should be called outside the engine-specified code (in
TCON, CRTC or TV Encoder code).

In order to preserve bisectability, we also switch the backend and layer
code in its own module.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
index 59b757350a1f..a251fb36c951 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -5,9 +5,10 @@ sun4i-tcon-y += sun4i_tcon.o
 sun4i-tcon-y += sun4i_rgb.o
 sun4i-tcon-y += sun4i_dotclock.o
 sun4i-tcon-y += sun4i_crtc.o
-sun4i-tcon-y += sun4i_layer.o
+
+sun4i-backend-y += sun4i_backend.o sun4i_layer.o
 
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i-drm.o sun4i-tcon.o
-obj-$(CONFIG_DRM_SUN4I)		+= sun4i_backend.o
+obj-$(CONFIG_DRM_SUN4I)		+= sun4i-backend.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.o