[PATCH 2/2] drm/atomic: add plane iterator macros

[Rob Clark]

Add helper macros to iterate the current, or incoming set of planes
attached to a crtc.  These helpers are only available for drivers
converted to use atomic-helpers.

Signed-off-by: Rob Clark <robdclark at gmail.com>
---
 Documentation/DocBook/drm.tmpl  |  1 +
 include/drm/drm_atomic_helper.h | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 8c54f9a..3789f2d 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2343,6 +2343,7 @@ void intel_crt_init(struct drm_device *dev)
 	<title>Atomic State Reset and Initialization</title>
 !Pdrivers/gpu/drm/drm_atomic_helper.c atomic state reset and initialization
       </sect3>
+!Iinclude/drm/drm_atomic_helper.h
 !Edrivers/gpu/drm/drm_atomic_helper.c
     </sect2>
     <sect2>
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 64b4e91..42d56e6 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -96,5 +96,31 @@ drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector);
 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 					  struct drm_connector_state *state);
 
+/**
+ * drm_crtc_for_each_plane - iterate over planes currently attached to crtc
+ * @plane: the loop cursor
+ * @crtc:  the crtc whose planes are iterated
+ *
+ * This iterates over the current state, useful (for example) when applying
+ * atomic state after it has been checked and swapped.  To iterate over the
+ * planes which *will* be attached (for ->atomic_check()) see
+ * drm_crtc_for_each_pending_plane()
+ */
+#define drm_crtc_for_each_plane(plane, crtc) \
+	list_for_each_entry((plane), &(crtc)->dev->mode_config.plane_list, head) \
+		if ((crtc)->state->plane_mask & (1 << drm_plane_index(plane)))
+
+/**
+ * drm_crtc_for_each_pending_plane - iterate over attached planes in new state
+ * @plane: the loop cursor
+ * @crtc_state: the incoming crtc-state
+ *
+ * Similar to drm_crtc_for_each_plane(), but iterates the planes that will be
+ * attached if the specified state is applied.  Useful during (for example)
+ * ->atomic_check() operations, to validate the incoming state
+ */
+#define drm_crtc_for_each_pending_plane(plane, crtc_state) \
+	list_for_each_entry((plane), &(crtc_state)->state->dev->mode_config.plane_list, head) \
+		if ((crtc_state)->plane_mask & (1 << drm_plane_index(plane)))
 
 #endif /* DRM_ATOMIC_HELPER_H_ */
-- 
1.9.3