drm/sti: implement atomic_check for the planes

Atomic update should never fail. Thus all checks must be done in
the atomic_check function for each plane (gdp, hqvdp and cursor).

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

drivers/gpu/drm/sti/sti_cursor.c

@@ -5,12 +5,10 @@
  *          for STMicroelectronics.
  * License terms:  GNU General Public License (GPL), version 2
  */
-#include <drm/drmP.h>
 
-#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
-#include <drm/drm_plane_helper.h>
 
 #include "sti_compositor.h"
 #include "sti_cursor.h"
@@ -110,42 +108,39 @@ static void sti_cursor_init(struct sti_cursor *cursor)
 						  (b * 5);
 }
 
-static void sti_cursor_atomic_update(struct drm_plane *drm_plane,
-				     struct drm_plane_state *oldstate)
+static int sti_cursor_atomic_check(struct drm_plane *drm_plane,
+				   struct drm_plane_state *state)
 {
-	struct drm_plane_state *state = drm_plane->state;
 	struct sti_plane *plane = to_sti_plane(drm_plane);
 	struct sti_cursor *cursor = to_sti_cursor(plane);
 	struct drm_crtc *crtc = state->crtc;
-	struct sti_mixer *mixer = to_sti_mixer(crtc);
 	struct drm_framebuffer *fb = state->fb;
-	struct drm_display_mode *mode = &crtc->mode;
-	int dst_x = state->crtc_x;
-	int dst_y = state->crtc_y;
-	int dst_w = clamp_val(state->crtc_w, 0, mode->crtc_hdisplay - dst_x);
-	int dst_h = clamp_val(state->crtc_h, 0, mode->crtc_vdisplay - dst_y);
+	struct drm_crtc_state *crtc_state;
+	struct drm_display_mode *mode;
+	int dst_x, dst_y, dst_w, dst_h;
+	int src_w, src_h;
+
+	/* no need for further checks if the plane is being disabled */
+	if (!crtc || !fb)
+		return 0;
+
+	crtc_state = drm_atomic_get_crtc_state(state->state, crtc);
+	mode = &crtc_state->mode;
+	dst_x = state->crtc_x;
+	dst_y = state->crtc_y;
+	dst_w = clamp_val(state->crtc_w, 0, mode->crtc_hdisplay - dst_x);
+	dst_h = clamp_val(state->crtc_h, 0, mode->crtc_vdisplay - dst_y);
 	/* src_x are in 16.16 format */
-	int src_w = state->src_w >> 16;
-	int src_h = state->src_h >> 16;
-	struct drm_gem_cma_object *cma_obj;
-	u32 y, x;
-	u32 val;
-
-	DRM_DEBUG_KMS("CRTC:%d (%s) drm plane:%d (%s)\n",
-		      crtc->base.id, sti_mixer_to_str(mixer),
-		      drm_plane->base.id, sti_plane_to_str(plane));
-	DRM_DEBUG_KMS("(%dx%d)@(%d,%d)\n", dst_w, dst_h, dst_x, dst_y);
-
-	dev_dbg(cursor->dev, "%s %s\n", __func__,
-		sti_plane_to_str(plane));
+	src_w = state->src_w >> 16;
+	src_h = state->src_h >> 16;
 
 	if (src_w < STI_CURS_MIN_SIZE ||
 	    src_h < STI_CURS_MIN_SIZE ||
 	    src_w > STI_CURS_MAX_SIZE ||
 	    src_h > STI_CURS_MAX_SIZE) {
 		DRM_ERROR("Invalid cursor size (%dx%d)\n",
 				src_w, src_h);
-		return;
+		return -EINVAL;
 	}
 
 	/* If the cursor size has changed, re-allocated the pixmap */
@@ -169,16 +164,46 @@ static void sti_cursor_atomic_update(struct drm_plane *drm_plane,
 							GFP_KERNEL | GFP_DMA);
 		if (!cursor->pixmap.base) {
 			DRM_ERROR("Failed to allocate memory for pixmap\n");
-			return;
+			return -EINVAL;
 		}
 	}
 
-	cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
-	if (!cma_obj) {
+	if (!drm_fb_cma_get_gem_obj(fb, 0)) {
 		DRM_ERROR("Can't get CMA GEM object for fb\n");
-		return;
+		return -EINVAL;
 	}
 
+	DRM_DEBUG_KMS("CRTC:%d (%s) drm plane:%d (%s)\n",
+		      crtc->base.id, sti_mixer_to_str(to_sti_mixer(crtc)),
+		      drm_plane->base.id, sti_plane_to_str(plane));
+	DRM_DEBUG_KMS("(%dx%d)@(%d,%d)\n", dst_w, dst_h, dst_x, dst_y);
+
+	return 0;
+}
+
+static void sti_cursor_atomic_update(struct drm_plane *drm_plane,
+				     struct drm_plane_state *oldstate)
+{
+	struct drm_plane_state *state = drm_plane->state;
+	struct sti_plane *plane = to_sti_plane(drm_plane);
+	struct sti_cursor *cursor = to_sti_cursor(plane);
+	struct drm_crtc *crtc = state->crtc;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_display_mode *mode;
+	int dst_x, dst_y;
+	struct drm_gem_cma_object *cma_obj;
+	u32 y, x;
+	u32 val;
+
+	if (!crtc || !fb)
+		return;
+
+	mode = &crtc->mode;
+	dst_x = state->crtc_x;
+	dst_y = state->crtc_y;
+
+	cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+
 	/* Convert ARGB8888 to CLUT8 */
 	sti_cursor_argb8888_to_clut8(cursor, (u32 *)cma_obj->vaddr);
 
@@ -212,7 +237,6 @@ static void sti_cursor_atomic_disable(struct drm_plane *drm_plane,
 				      struct drm_plane_state *oldstate)
 {
 	struct sti_plane *plane = to_sti_plane(drm_plane);
-	struct sti_mixer *mixer = to_sti_mixer(drm_plane->crtc);
 
 	if (!drm_plane->crtc) {
 		DRM_DEBUG_DRIVER("drm plane:%d not enabled\n",
@@ -221,13 +245,15 @@ static void sti_cursor_atomic_disable(struct drm_plane *drm_plane,
 	}
 
 	DRM_DEBUG_DRIVER("CRTC:%d (%s) drm plane:%d (%s)\n",
-			 drm_plane->crtc->base.id, sti_mixer_to_str(mixer),
+			 drm_plane->crtc->base.id,
+			 sti_mixer_to_str(to_sti_mixer(drm_plane->crtc)),
 			 drm_plane->base.id, sti_plane_to_str(plane));
 
 	plane->status = STI_PLANE_DISABLING;
 }
 
 static const struct drm_plane_helper_funcs sti_cursor_helpers_funcs = {
+	.atomic_check = sti_cursor_atomic_check,
 	.atomic_update = sti_cursor_atomic_update,
 	.atomic_disable = sti_cursor_atomic_disable,
 };