drm/exynos: Add plane support with fimd

The exynos fimd supports 5 window overlays. Only one window overlay of
fimd is used by the crtc, so we need plane feature to use the rest
window overlays.

This creates one ioctl exynos specific - DRM_EXYNOS_PLANE_SET_ZPOS, it
is the ioctl to decide for user to assign which window overlay.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/include/drm/exynos_drm.h b/include/drm/exynos_drm.h
index 1205043..7a2262a 100644
--- a/include/drm/exynos_drm.h
+++ b/include/drm/exynos_drm.h
@@ -74,9 +74,16 @@
 	uint64_t mapped;
 };
 
+struct drm_exynos_plane_set_zpos {
+	__u32 plane_id;
+	__s32 zpos;
+};
+
 #define DRM_EXYNOS_GEM_CREATE		0x00
 #define DRM_EXYNOS_GEM_MAP_OFFSET	0x01
 #define DRM_EXYNOS_GEM_MMAP		0x02
+/* Reserved 0x03 ~ 0x05 for exynos specific gem ioctl */
+#define DRM_EXYNOS_PLANE_SET_ZPOS	0x06
 
 #define DRM_IOCTL_EXYNOS_GEM_CREATE		DRM_IOWR(DRM_COMMAND_BASE + \
 		DRM_EXYNOS_GEM_CREATE, struct drm_exynos_gem_create)
@@ -87,6 +94,9 @@
 #define DRM_IOCTL_EXYNOS_GEM_MMAP	DRM_IOWR(DRM_COMMAND_BASE + \
 		DRM_EXYNOS_GEM_MMAP, struct drm_exynos_gem_mmap)
 
+#define DRM_IOCTL_EXYNOS_PLANE_SET_ZPOS	DRM_IOWR(DRM_COMMAND_BASE + \
+		DRM_EXYNOS_PLANE_SET_ZPOS, struct drm_exynos_plane_set_zpos)
+
 /**
  * Platform Specific Structure for DRM based FIMD.
  *