[1/4] drm: add support for generic zpos property
diff mbox

Message ID 1451998373-13708-2-git-send-email-m.szyprowski@samsung.com
State New, archived
Headers show

Commit Message

Marek Szyprowski Jan. 5, 2016, 12:52 p.m. UTC
This patch adds support for generic plane's zpos property property with
well-defined semantics:
- added zpos properties to drm core and plane state structures
- added helpers for normalizing zpos properties of given set of planes
- well defined semantics: planes are sorted by zpos values and then plane
  id value if zpos equals

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 Documentation/DocBook/gpu.tmpl      | 14 ++++++++--
 drivers/gpu/drm/drm_atomic.c        |  4 +++
 drivers/gpu/drm/drm_atomic_helper.c | 52 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_crtc.c          | 13 ++++++++++
 include/drm/drm_atomic_helper.h     |  2 ++
 include/drm/drm_crtc.h              | 13 ++++++++++
 6 files changed, 96 insertions(+), 2 deletions(-)

Patch
diff mbox

diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index 6c6e81a9eaf4..e81acd999891 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -2004,7 +2004,7 @@  void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >Description/Restrictions</td>
 	</tr>
 	<tr>
-	<td rowspan="37" valign="top" >DRM</td>
+	<td rowspan="38" valign="top" >DRM</td>
 	<td valign="top" >Generic</td>
 	<td valign="top" >“rotation”</td>
 	<td valign="top" >BITMASK</td>
@@ -2256,7 +2256,7 @@  void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >property to suggest an Y offset for a connector</td>
 	</tr>
 	<tr>
-	<td rowspan="3" valign="top" >Optional</td>
+	<td rowspan="4" valign="top" >Optional</td>
 	<td valign="top" >“scaling mode”</td>
 	<td valign="top" >ENUM</td>
 	<td valign="top" >{ "None", "Full", "Center", "Full aspect" }</td>
@@ -2280,6 +2280,16 @@  void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >TBD</td>
 	</tr>
 	<tr>
+	<td valign="top" > "zpos" </td>
+	<td valign="top" >RANGE</td>
+	<td valign="top" >Min=0, Max=255</td>
+	<td valign="top" >Plane</td>
+	<td valign="top" >Plane's 'z' position during blending (0 for background, 255 for frontmost).
+		If two planes assigned to same CRTC have equal zpos values, the plane with higher plane
+		id is treated as closer to front. Can be IMMUTABLE if driver doesn't support changing
+		plane's order.</td>
+	</tr>
+	<tr>
 	<td rowspan="20" valign="top" >i915</td>
 	<td rowspan="2" valign="top" >Generic</td>
 	<td valign="top" >"Broadcast RGB"</td>
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 6a21e5c378c1..97bb069cb6a3 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -614,6 +614,8 @@  int drm_atomic_plane_set_property(struct drm_plane *plane,
 		state->src_h = val;
 	} else if (property == config->rotation_property) {
 		state->rotation = val;
+	} else if (property == config->zpos_property) {
+		state->zpos = val;
 	} else if (plane->funcs->atomic_set_property) {
 		return plane->funcs->atomic_set_property(plane, state,
 				property, val);
@@ -670,6 +672,8 @@  drm_atomic_plane_get_property(struct drm_plane *plane,
 		*val = state->src_h;
 	} else if (property == config->rotation_property) {
 		*val = state->rotation;
+	} else if (property == config->zpos_property) {
+		*val = state->zpos;
 	} else if (plane->funcs->atomic_get_property) {
 		return plane->funcs->atomic_get_property(plane, state, property, val);
 	} else {
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 268d37f26960..de3ca33eb696 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -31,6 +31,7 @@ 
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_atomic_helper.h>
 #include <linux/fence.h>
+#include <linux/sort.h>
 
 /**
  * DOC: overview
@@ -2781,3 +2782,54 @@  void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 	kfree(state);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
+
+/**
+ * __drm_atomic_helper_plane_zpos_cmp - compare zpos value of two planes
+ * @a: pointer to first plane
+ * @b: pointer to second plane
+ *
+ * This function is used for comparing two planes while sorting them to assign
+ * a normalized zpos values. Planes are compared first by their zpos values,
+ * then in case they equal, by plane id.
+ */
+static int __drm_atomic_helper_plane_zpos_cmp(const void *a, const void *b)
+{
+	const struct drm_plane *pa = *(struct drm_plane **)a;
+	const struct drm_plane *pb = *(struct drm_plane **)b;
+	int zpos_a = 0, zpos_b = 0;
+
+	if (pa->state)
+		zpos_a = pa->state->zpos << 16;
+	if (pb->state)
+		zpos_b = pb->state->zpos << 16;
+
+	zpos_a += pa->base.id;
+	zpos_b += pb->base.id;
+
+	return zpos_a - zpos_b;
+}
+
+/**
+ * drm_atomic_helper_normalize_zpos - calculate normalized zpos values
+ * @planes: arrays of pointer to planes to consider for normalization
+ * @count: number of planes in the above array
+ *
+ * This function takes arrays of pointers to planes and calculates normalized
+ * zpos value for them taking into account each planes[i]->state->zpos value
+ * and plane's id (if zpos equals). The plane[i]->state->normalized_zpos is
+ * then filled with uniqe values from 0 to count-1.
+ * Note: a side effect of this function is the fact that the planes array will
+ * be modified (sorted). It is up to the called to construct planes array with
+ * all planes that have been assigned to given crtc.
+ */
+void drm_atomic_helper_normalize_zpos(struct drm_plane *planes[], int count)
+{
+	int i;
+
+	sort(planes, count, sizeof(struct drm_plane *),
+	     __drm_atomic_helper_plane_zpos_cmp, NULL);
+	for (i = 0; i < count; i++)
+		if (planes[i]->state)
+			planes[i]->state->normalized_zpos = i;
+}
+EXPORT_SYMBOL(drm_atomic_helper_normalize_zpos);
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 62fa95fa5471..51474ea179f6 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -5879,6 +5879,19 @@  struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_mode_create_rotation_property);
 
+struct drm_property *drm_plane_create_zpos_property(struct drm_device *dev)
+{
+	return drm_property_create_range(dev, 0, "zpos", 0, 255);
+}
+EXPORT_SYMBOL(drm_plane_create_zpos_property);
+
+struct drm_property *drm_plane_create_zpos_immutable_property(struct drm_device *dev)
+{
+	return drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "zpos",
+					 0, 255);
+}
+EXPORT_SYMBOL(drm_plane_create_zpos_immutable_property);
+
 /**
  * DOC: Tile group
  *
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index a286cce98720..2a7ade5ad8bd 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -141,6 +141,8 @@  __drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 					  struct drm_connector_state *state);
 
+void drm_atomic_helper_normalize_zpos(struct drm_plane *planes[], int count);
+
 /**
  * drm_atomic_crtc_for_each_plane - iterate over planes currently attached to CRTC
  * @plane: the loop cursor
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 3b040b355472..5021aa0237b9 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1243,6 +1243,9 @@  struct drm_connector {
  *	plane (in 16.16)
  * @src_w: width of visible portion of plane (in 16.16)
  * @src_h: height of visible portion of plane (in 16.16)
+ * @zpos: priority of the given plane on crtc (optional)
+ * @normalized_zpos: normalized value of zpos: uniqe, range from 0 to
+ *	(number of planes - 1) for given crtc
  * @state: backpointer to global drm_atomic_state
  */
 struct drm_plane_state {
@@ -1263,6 +1266,10 @@  struct drm_plane_state {
 	/* Plane rotation */
 	unsigned int rotation;
 
+	/* Plane zpos */
+	unsigned int zpos;
+	unsigned int normalized_zpos;
+
 	struct drm_atomic_state *state;
 };
 
@@ -2083,6 +2090,8 @@  struct drm_mode_config {
 	struct drm_property *tile_property;
 	struct drm_property *plane_type_property;
 	struct drm_property *rotation_property;
+	struct drm_property *zpos_property;
+	struct drm_property *zpos_immutable_property;
 	struct drm_property *prop_src_x;
 	struct drm_property *prop_src_y;
 	struct drm_property *prop_src_w;
@@ -2484,6 +2493,10 @@  extern struct drm_property *drm_mode_create_rotation_property(struct drm_device
 extern unsigned int drm_rotation_simplify(unsigned int rotation,
 					  unsigned int supported_rotations);
 
+extern struct drm_property *drm_plane_create_zpos_property(struct drm_device *dev);
+
+extern struct drm_property *drm_plane_create_zpos_immutable_property(struct drm_device *dev);
+
 /* Helpers */
 
 static inline struct drm_plane *drm_plane_find(struct drm_device *dev,