drm/exynos: create exynos_check_plane()

Split update plane in two parts, an initial check part that can fail
and the update part that can't fail.

This is a important step for the upcoming atomic modesetting support.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_crtc.c

@@ -92,6 +92,7 @@ exynos_drm_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
 	struct drm_framebuffer *fb = crtc->primary->fb;
 	unsigned int crtc_w;
 	unsigned int crtc_h;
+	int ret;
 
 	/*
 	 * copy the mode data adjusted by mode_fixup() into crtc->mode
@@ -99,10 +100,16 @@ exynos_drm_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
 	 */
 	memcpy(&crtc->mode, adjusted_mode, sizeof(*adjusted_mode));
 
+	ret = exynos_check_plane(crtc->primary, fb);
+	if (ret < 0)
+		return ret;
+
 	crtc_w = fb->width - x;
 	crtc_h = fb->height - y;
-	return exynos_plane_mode_set(crtc->primary, crtc, fb, 0, 0,
+	exynos_plane_mode_set(crtc->primary, crtc, fb, 0, 0,
 			      crtc_w, crtc_h, x, y, crtc_w, crtc_h);
+
+	return 0;
 }
 
 static int exynos_drm_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,

drivers/gpu/drm/exynos/exynos_drm_plane.c

@@ -12,6 +12,7 @@
 #include <drm/drmP.h>
 
 #include <drm/exynos_drm.h>
+#include <drm/drm_plane_helper.h>
 #include "exynos_drm_drv.h"
 #include "exynos_drm_crtc.h"
 #include "exynos_drm_fb.h"
@@ -61,16 +62,9 @@ static int exynos_plane_get_size(int start, unsigned length, unsigned last)
 	return size;
 }
 
-int exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
-			  struct drm_framebuffer *fb, int crtc_x, int crtc_y,
-			  unsigned int crtc_w, unsigned int crtc_h,
-			  uint32_t src_x, uint32_t src_y,
-			  uint32_t src_w, uint32_t src_h)
+int exynos_check_plane(struct drm_plane *plane, struct drm_framebuffer *fb)
 {
 	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
-	struct exynos_drm_crtc *exynos_crtc = to_exynos_crtc(crtc);
-	unsigned int actual_w;
-	unsigned int actual_h;
 	int nr;
 	int i;
 
@@ -89,6 +83,20 @@ int exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
 				i, (unsigned long)exynos_plane->dma_addr[i]);
 	}
 
+	return 0;
+}
+
+void exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
+			  struct drm_framebuffer *fb, int crtc_x, int crtc_y,
+			  unsigned int crtc_w, unsigned int crtc_h,
+			  uint32_t src_x, uint32_t src_y,
+			  uint32_t src_w, uint32_t src_h)
+{
+	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
+	struct exynos_drm_crtc *exynos_crtc = to_exynos_crtc(crtc);
+	unsigned int actual_w;
+	unsigned int actual_h;
+
 	actual_w = exynos_plane_get_size(crtc_x, crtc_w, crtc->mode.hdisplay);
 	actual_h = exynos_plane_get_size(crtc_y, crtc_h, crtc->mode.vdisplay);
 
@@ -135,8 +143,6 @@ int exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
 
 	if (exynos_crtc->ops->win_mode_set)
 		exynos_crtc->ops->win_mode_set(exynos_crtc, exynos_plane);
-
-	return 0;
 }
 
 void exynos_plane_dpms(struct drm_plane *plane, int mode)
@@ -177,12 +183,14 @@ exynos_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
 	int ret;
 
-	ret = exynos_plane_mode_set(plane, crtc, fb, crtc_x, crtc_y,
-			crtc_w, crtc_h, src_x >> 16, src_y >> 16,
-			src_w >> 16, src_h >> 16);
+	ret = exynos_check_plane(plane, fb);
 	if (ret < 0)
 		return ret;
 
+	exynos_plane_mode_set(plane, crtc, fb, crtc_x, crtc_y,
+			      crtc_w, crtc_h, src_x >> 16, src_y >> 16,
+			      src_w >> 16, src_h >> 16);
+
 	if (exynos_crtc->ops->win_commit)
 		exynos_crtc->ops->win_commit(exynos_crtc, exynos_plane->zpos);
 

drivers/gpu/drm/exynos/exynos_drm_plane.h

@@ -9,7 +9,8 @@
  *
  */
 
-int exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
+int exynos_check_plane(struct drm_plane *plane, struct drm_framebuffer *fb);
+void exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
 			   struct drm_framebuffer *fb, int crtc_x, int crtc_y,
 			   unsigned int crtc_w, unsigned int crtc_h,
 			   uint32_t src_x, uint32_t src_y,