drm/exynos: add generic check for plane state

This patch adds generic check for plane state - display area dimensions,
so drivers can always assume that they get valid plane state to set.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -89,6 +89,9 @@ struct exynos_drm_plane {
 	struct drm_framebuffer *pending_fb;
 };
 
+#define EXYNOS_DRM_PLANE_CAP_DOUBLE	(1 << 0)
+#define EXYNOS_DRM_PLANE_CAP_SCALE	(1 << 1)
+
 /*
  * Exynos DRM plane configuration structure.
  *

drivers/gpu/drm/exynos/exynos_drm_plane.c

@@ -173,6 +173,36 @@ static struct drm_plane_funcs exynos_plane_funcs = {
 	.atomic_destroy_state = exynos_drm_plane_destroy_state,
 };
 
+static int
+exynos_drm_plane_check_size(const struct exynos_drm_plane_config *config,
+			    struct exynos_drm_plane_state *state)
+{
+	bool width_ok = false, height_ok = false;
+
+	if (config->capabilities & EXYNOS_DRM_PLANE_CAP_SCALE)
+		return 0;
+
+	if (state->src.w == state->crtc.w)
+		width_ok = true;
+
+	if (state->src.h == state->crtc.h)
+		height_ok = true;
+
+	if ((config->capabilities & EXYNOS_DRM_PLANE_CAP_DOUBLE) &&
+	    state->h_ratio == (1 << 15))
+		width_ok = true;
+
+	if ((config->capabilities & EXYNOS_DRM_PLANE_CAP_DOUBLE) &&
+	    state->v_ratio == (1 << 15))
+		height_ok = true;
+
+	if (width_ok & height_ok)
+		return 0;
+
+	DRM_DEBUG_KMS("scaling mode is not supported");
+	return -ENOTSUPP;
+}
+
 static int exynos_plane_atomic_check(struct drm_plane *plane,
 				     struct drm_plane_state *state)
 {
@@ -187,6 +217,7 @@ static int exynos_plane_atomic_check(struct drm_plane *plane,
 	/* translate state into exynos_state */
 	exynos_plane_mode_set(exynos_state);
 
+	ret = exynos_drm_plane_check_size(exynos_plane->config, exynos_state);
 	return ret;
 }
 

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -117,16 +117,19 @@ static const struct exynos_drm_plane_config plane_configs[MIXER_WIN_NR] = {
 		.type = DRM_PLANE_TYPE_PRIMARY,
 		.pixel_formats = mixer_formats,
 		.num_pixel_formats = ARRAY_SIZE(mixer_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_DOUBLE,
 	}, {
 		.zpos = 1,
 		.type = DRM_PLANE_TYPE_CURSOR,
 		.pixel_formats = mixer_formats,
 		.num_pixel_formats = ARRAY_SIZE(mixer_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_DOUBLE,
 	}, {
 		.zpos = 2,
 		.type = DRM_PLANE_TYPE_OVERLAY,
 		.pixel_formats = vp_formats,
 		.num_pixel_formats = ARRAY_SIZE(vp_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_SCALE,
 	},
 };