drm/i915: Add rotation readout for plane initial config

If we need to force a full plane update before userspace/fbdev
have given us a proper plane state we should try to maintain the
current plane state as much as possible (apart from the parts
of the state we're trying to fix up with the plane update).
To that end add basic readout for the plane rotation and
maintain it during the initial fb takeover.

Cc: Hans de Goede <hdegoede@redhat.com>
Fixes: 516a49cc ("drm/i915: Fix assert_plane() warning on bootup with external display")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181120135450.3634-2-ville.syrjala@linux.intel.comTested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/i915/intel_display.c

@@ -2831,6 +2831,7 @@ intel_find_initial_plane_obj(struct intel_crtc *intel_crtc,
 	return;
 
 valid_fb:
+	intel_state->base.rotation = plane_config->rotation;
 	intel_fill_fb_ggtt_view(&intel_state->view, fb,
 				intel_state->base.rotation);
 	intel_state->color_plane[0].stride =
@@ -7787,8 +7788,15 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc,
 			plane_config->tiling = I915_TILING_X;
 			fb->modifier = I915_FORMAT_MOD_X_TILED;
 		}
+
+		if (val & DISPPLANE_ROTATE_180)
+			plane_config->rotation = DRM_MODE_ROTATE_180;
 	}
 
+	if (IS_CHERRYVIEW(dev_priv) && pipe == PIPE_B &&
+	    val & DISPPLANE_MIRROR)
+		plane_config->rotation |= DRM_MODE_REFLECT_X;
+
 	pixel_format = val & DISPPLANE_PIXFORMAT_MASK;
 	fourcc = i9xx_format_to_fourcc(pixel_format);
 	fb->format = drm_format_info(fourcc);
@@ -8898,6 +8906,29 @@ skylake_get_initial_plane_config(struct intel_crtc *crtc,
 		goto error;
 	}
 
+	/*
+	 * DRM_MODE_ROTATE_ is counter clockwise to stay compatible with Xrandr
+	 * while i915 HW rotation is clockwise, thats why this swapping.
+	 */
+	switch (val & PLANE_CTL_ROTATE_MASK) {
+	case PLANE_CTL_ROTATE_0:
+		plane_config->rotation = DRM_MODE_ROTATE_0;
+		break;
+	case PLANE_CTL_ROTATE_90:
+		plane_config->rotation = DRM_MODE_ROTATE_270;
+		break;
+	case PLANE_CTL_ROTATE_180:
+		plane_config->rotation = DRM_MODE_ROTATE_180;
+		break;
+	case PLANE_CTL_ROTATE_270:
+		plane_config->rotation = DRM_MODE_ROTATE_90;
+		break;
+	}
+
+	if (INTEL_GEN(dev_priv) >= 10 &&
+	    val & PLANE_CTL_FLIP_HORIZONTAL)
+		plane_config->rotation |= DRM_MODE_REFLECT_X;
+
 	base = I915_READ(PLANE_SURF(pipe, plane_id)) & 0xfffff000;
 	plane_config->base = base;
 

drivers/gpu/drm/i915/intel_drv.h

@@ -572,6 +572,7 @@ struct intel_initial_plane_config {
 	unsigned int tiling;
 	int size;
 	u32 base;
+	u8 rotation;
 };
 
 #define SKL_MIN_SRC_W 8