drm/i915: Add support for half float framebuffers for skl+

skl+ supports fp16 pixel formats on all universal planes. Add the
necessary bits to expose that capability. The main different to
icl is that we can't scale fp16, so need to add the relevant
checks.

v2: Rebase on top of icl fp16
    Split skl+ bits into a separate patch
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191015193035.25982-8-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -5640,10 +5640,6 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 	case DRM_FORMAT_ARGB8888:
 	case DRM_FORMAT_XRGB2101010:
 	case DRM_FORMAT_XBGR2101010:
-	case DRM_FORMAT_XBGR16161616F:
-	case DRM_FORMAT_ABGR16161616F:
-	case DRM_FORMAT_XRGB16161616F:
-	case DRM_FORMAT_ARGB16161616F:
 	case DRM_FORMAT_YUYV:
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_UYVY:
@@ -5659,6 +5655,13 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 	case DRM_FORMAT_XVYU12_16161616:
 	case DRM_FORMAT_XVYU16161616:
 		break;
+	case DRM_FORMAT_XBGR16161616F:
+	case DRM_FORMAT_ABGR16161616F:
+	case DRM_FORMAT_XRGB16161616F:
+	case DRM_FORMAT_ARGB16161616F:
+		if (INTEL_GEN(dev_priv) >= 11)
+			break;
+		/* fall through */
 	default:
 		DRM_DEBUG_KMS("[PLANE:%d:%s] FB:%d unsupported scaling format 0x%x\n",
 			      intel_plane->base.base.id, intel_plane->base.name,

drivers/gpu/drm/i915/display/intel_sprite.c

@@ -1832,6 +1832,11 @@ static bool intel_fb_scalable(const struct drm_framebuffer *fb)
 	switch (fb->format->format) {
 	case DRM_FORMAT_C8:
 		return false;
+	case DRM_FORMAT_XRGB16161616F:
+	case DRM_FORMAT_ARGB16161616F:
+	case DRM_FORMAT_XBGR16161616F:
+	case DRM_FORMAT_ABGR16161616F:
+		return INTEL_GEN(to_i915(fb->dev)) >= 11;
 	default:
 		return true;
 	}
@@ -2359,6 +2364,8 @@ static const u32 skl_plane_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB2101010,
 	DRM_FORMAT_XBGR2101010,
+	DRM_FORMAT_XRGB16161616F,
+	DRM_FORMAT_XBGR16161616F,
 	DRM_FORMAT_YUYV,
 	DRM_FORMAT_YVYU,
 	DRM_FORMAT_UYVY,
@@ -2374,6 +2381,8 @@ static const u32 skl_planar_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB2101010,
 	DRM_FORMAT_XBGR2101010,
+	DRM_FORMAT_XRGB16161616F,
+	DRM_FORMAT_XBGR16161616F,
 	DRM_FORMAT_YUYV,
 	DRM_FORMAT_YVYU,
 	DRM_FORMAT_UYVY,
@@ -2390,6 +2399,8 @@ static const u32 glk_planar_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB2101010,
 	DRM_FORMAT_XBGR2101010,
+	DRM_FORMAT_XRGB16161616F,
+	DRM_FORMAT_XBGR16161616F,
 	DRM_FORMAT_YUYV,
 	DRM_FORMAT_YVYU,
 	DRM_FORMAT_UYVY,