drm: Add drm_crtc_init_with_planes() (v2)

Add a new drm_crtc_init_with_planes() to allow drivers to provide
specific primary and cursor planes at CRTC initialization. The existing
drm_crtc_init() interface remains to avoid driver churn in existing
drivers; it will initialize the CRTC with a plane helper-created primary
plane and no cursor plane.

v2:
- Move drm_crtc_init() to plane helper file so that nothing in the DRM
core depends on helpers. [suggested by Daniel Vetter]
- Keep cursor parameter to drm_crtc_init_with_planes() a void* until
we actually add cursor support. [suggested by Daniel Vetter]

Signed-off-by: Matt Roper <[e-mail]>
Reviewed-by: Rob Clark <[e-mail]>

drivers/gpu/drm/drm_crtc.c

···
 EXPORT_SYMBOL(drm_framebuffer_remove);
 
 /**
- * drm_crtc_init - Initialise a new CRTC object
+ * drm_crtc_init_with_planes - Initialise a new CRTC object with
+ *    specified primary and cursor planes.
  * @dev: DRM device
  * @crtc: CRTC object to init
+ * @primary: Primary plane for CRTC
+ * @cursor: Cursor plane for CRTC
  * @funcs: callbacks for the new CRTC
  *
  * Inits a new object created as base part of a driver crtc object.
···
  * Returns:
  * Zero on success, error code on failure.
  */
-int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
-		   const struct drm_crtc_funcs *funcs)
+int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
+			      struct drm_plane *primary,
+			      void *cursor,
+			      const struct drm_crtc_funcs *funcs)
 {
 	int ret;
 
···
 	list_add_tail(&crtc->head, &dev->mode_config.crtc_list);
 	dev->mode_config.num_crtc++;
 
+	crtc->primary = primary;
+	if (primary)
+		primary->possible_crtcs = 1 << drm_crtc_index(crtc);
+
  out:
 	drm_modeset_unlock_all(dev);
 
 	return ret;
 }
-EXPORT_SYMBOL(drm_crtc_init);
+EXPORT_SYMBOL(drm_crtc_init_with_planes);
 
 /**
  * drm_crtc_cleanup - Clean up the core crtc usage
···
 
 	ret = crtc->funcs->set_config(set);
 	if (ret == 0) {
+		crtc->primary->crtc = crtc;
+
 		/* crtc->fb must be updated by ->set_config, enforces this. */
 		WARN_ON(fb != crtc->fb);
 	}

drivers/gpu/drm/drm_plane_helper.c

···
 }
 EXPORT_SYMBOL(drm_primary_helper_create_plane);
 
+/**
+ * drm_crtc_init - Legacy CRTC initialization function
+ * @dev: DRM device
+ * @crtc: CRTC object to init
+ * @funcs: callbacks for the new CRTC
+ *
+ * Initialize a CRTC object with a default helper-provided primary plane and no
+ * cursor plane.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
+		  const struct drm_crtc_funcs *funcs)
+{
+	struct drm_plane *primary;
+
+	primary = drm_primary_helper_create_plane(dev, NULL, 0);
+	return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
+}
+EXPORT_SYMBOL(drm_crtc_init);

include/drm/drm_crtc.h

···
  * @dev: parent DRM device
  * @head: list management
  * @base: base KMS object for ID tracking etc.
+ * @primary: primary plane for this CRTC
+ * @cursor: cursor plane for this CRTC
  * @enabled: is this CRTC enabled?
  * @mode: current mode timings
  * @hwmode: mode timings as programmed to hw regs
···
 	struct mutex mutex;
 
 	struct drm_mode_object base;
+
+	/* primary and cursor planes for CRTC */
+	struct drm_plane *primary;
+	struct drm_plane *cursor;
 
 	/* framebuffer the connector is currently bound to */
 	struct drm_framebuffer *fb;
···
 extern void drm_modeset_unlock_all(struct drm_device *dev);
 extern void drm_warn_on_modeset_not_all_locked(struct drm_device *dev);
 
+extern int drm_crtc_init_with_planes(struct drm_device *dev,
+				     struct drm_crtc *crtc,
+				     struct drm_plane *primary,
+				     void *cursor,
+				     const struct drm_crtc_funcs *funcs);
 extern int drm_crtc_init(struct drm_device *dev,
 			 struct drm_crtc *crtc,
 			 const struct drm_crtc_funcs *funcs);