[PATCH v2 0/3] drm/exynos: introduce generic zpos property

[PATCH v2 0/3] drm/exynos: introduce generic zpos property

[Marek Szyprowski]

Hello all,

This patch series is a continuation of rework of blending support in
Exynos DRM driver. Some background can be found here:
http://www.spinics.net/lists/dri-devel/msg96969.html

Daniel Vetter suggested that zpos property should be made generic, with
well-defined semantics. This patchset is my proposal for such generic
zpos property:
- 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.

Patches are based on top of latest exynos-drm-next branch.

Best regards
Marek Szyprowski
Samsung R&D Institute Poland

Changelog:

v2:
- dropped 2 fixes for Exynos DRM, which got merged in meantime
- added more comments and kernel docs for core functions as suggested
  by Daniel Vetter
- reworked initialization of zpos properties (moved assiging property
  class to common code), now the code in the driver is even simpler
- while reworking of intialization of zpos property code, did the same
  change to generic rotation property

v1: http://www.spinics.net/lists/dri-devel/msg97709.html
- initial version

Patch summary:

Marek Szyprowski (3):
  drm: add generic zpos property
  drm/exynos: use generic code for managing zpos plane property
  drm: simplify initialization of rotation property

 Documentation/DocBook/gpu.tmpl                  | 14 ++++-
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 10 ++--
 drivers/gpu/drm/drm_atomic.c                    |  4 ++
 drivers/gpu/drm/drm_atomic_helper.c             | 45 +++++++++++++++
 drivers/gpu/drm/drm_crtc.c                      | 73 +++++++++++++++++++++++--
 drivers/gpu/drm/exynos/exynos_drm_drv.h         |  1 -
 drivers/gpu/drm/exynos/exynos_drm_plane.c       | 66 +++++-----------------
 drivers/gpu/drm/exynos/exynos_mixer.c           | 19 ++++++-
 drivers/gpu/drm/i915/intel_display.c            |  6 +-
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c       |  3 +-
 drivers/gpu/drm/omapdrm/omap_drv.c              |  3 +-
 include/drm/drm_atomic_helper.h                 |  2 +
 include/drm/drm_crtc.h                          | 16 +++++-
 13 files changed, 182 insertions(+), 80 deletions(-)

-- 
1.9.2

[PATCH v2 1/3] drm: add generic zpos property

[Marek Szyprowski]

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 | 45 +++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_crtc.c          | 47 +++++++++++++++++++++++++++++++++++++
 include/drm/drm_atomic_helper.h     |  2 ++
 include/drm/drm_crtc.h              | 12 ++++++++++
 6 files changed, 122 insertions(+), 2 deletions(-)

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
+		planes' 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..167d32346e2f 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 +2782,47 @@ void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 	kfree(state);
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
+
+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. Planes are compared first by their zpos values, then in case
+ * they equal, by plane id. Plane with lowest zpos value is at the bottom.
+ * 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 caller 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..e33866084b70 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -5880,6 +5880,53 @@ struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 EXPORT_SYMBOL(drm_mode_create_rotation_property);
 
 /**
+ * drm_mode_create_zpos_property - create muttable zpos property
+ * @dev: DRM device
+ *
+ * This function initializes generic muttable zpos property and enables support
+ * for it in drm core. Drivers can then attach this property to planes to enable
+ * support for configurable planes arrangement during blending operation.
+ * Drivers can also use drm_atomic_helper_normalize_zpos() function to calculate
+ * drm_plane_state->normalized_zpos values.
+ */
+int drm_mode_create_zpos_property(struct drm_device *dev)
+{
+	struct drm_property *prop;
+
+	prop = drm_property_create_range(dev, 0, "zpos", 0, 255);
+	if (!prop)
+		return -ENOMEM;
+
+	dev->mode_config.zpos_property = prop;
+	return 0;
+}
+EXPORT_SYMBOL(drm_mode_create_zpos_property);
+
+/**
+ * drm_plane_create_zpos_property - create immuttable zpos property
+ * @dev: DRM device
+ *
+ * This function initializes generic immuttable zpos property and enables
+ * support for it in drm core. Using this property driver lets userspace
+ * to get the arrangement of the planes for blending operation and notifies
+ * it that the hardware (or driver) doesn't support changing of the planes'
+ * order.
+ */
+int drm_mode_create_zpos_immutable_property(struct drm_device *dev)
+{
+	struct drm_property *prop;
+
+	prop = drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "zpos",
+					 0, 255);
+	if (!prop)
+		return -ENOMEM;
+
+	dev->mode_config.zpos_immutable_property = prop;
+	return 0;
+}
+EXPORT_SYMBOL(drm_mode_create_zpos_immutable_property);
+
+/**
  * DOC: Tile group
  *
  * Tile groups are used to represent tiled monitors with a unique
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..13035e2c5e51 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 +2493,9 @@ 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 int drm_mode_create_zpos_property(struct drm_device *dev);
+extern int drm_mode_create_zpos_immutable_property(struct drm_device *dev);
+
 /* Helpers */
 
 static inline struct drm_plane *drm_plane_find(struct drm_device *dev,
-- 
1.9.2

[PATCH v2 2/3] drm/exynos: use generic code for managing zpos plane property

[Marek Szyprowski]

This patch replaces zpos property handling custom code in Exynos DRM
driver with calls to generic DRM code.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_drv.h   |  1 -
 drivers/gpu/drm/exynos/exynos_drm_plane.c | 66 +++++++------------------------
 drivers/gpu/drm/exynos/exynos_mixer.c     | 19 +++++++--
 3 files changed, 30 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 17b5ded72ff1..244ae6c4482c 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -217,7 +217,6 @@ struct exynos_drm_private {
 	 * this array is used to be aware of which crtc did it request vblank.
 	 */
 	struct drm_crtc *crtc[MAX_CRTC];
-	struct drm_property *plane_zpos_property;
 
 	unsigned long da_start;
 	unsigned long da_space_size;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_plane.c b/drivers/gpu/drm/exynos/exynos_drm_plane.c
index d86227236f55..ba46bc3de796 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_plane.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_plane.c
@@ -137,9 +137,9 @@ static void exynos_drm_plane_reset(struct drm_plane *plane)
 
 	exynos_state = kzalloc(sizeof(*exynos_state), GFP_KERNEL);
 	if (exynos_state) {
-		exynos_state->zpos = exynos_plane->config->zpos;
 		plane->state = &exynos_state->base;
 		plane->state->plane = plane;
+		plane->state->zpos = exynos_plane->config->zpos;
 	}
 }
 
@@ -155,7 +155,6 @@ exynos_drm_plane_duplicate_state(struct drm_plane *plane)
 		return NULL;
 
 	__drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
-	copy->zpos = exynos_state->zpos;
 	return &copy->base;
 }
 
@@ -168,43 +167,6 @@ static void exynos_drm_plane_destroy_state(struct drm_plane *plane,
 	kfree(old_exynos_state);
 }
 
-static int exynos_drm_plane_atomic_set_property(struct drm_plane *plane,
-						struct drm_plane_state *state,
-						struct drm_property *property,
-						uint64_t val)
-{
-	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
-	struct exynos_drm_plane_state *exynos_state =
-					to_exynos_plane_state(state);
-	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
-	const struct exynos_drm_plane_config *config = exynos_plane->config;
-
-	if (property == dev_priv->plane_zpos_property &&
-	    (config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS))
-		exynos_state->zpos = val;
-	else
-		return -EINVAL;
-
-	return 0;
-}
-
-static int exynos_drm_plane_atomic_get_property(struct drm_plane *plane,
-					  const struct drm_plane_state *state,
-					  struct drm_property *property,
-					  uint64_t *val)
-{
-	const struct exynos_drm_plane_state *exynos_state =
-		container_of(state, const struct exynos_drm_plane_state, base);
-	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
-
-	if (property == dev_priv->plane_zpos_property)
-		*val = exynos_state->zpos;
-	else
-		return -EINVAL;
-
-	return 0;
-}
-
 static struct drm_plane_funcs exynos_plane_funcs = {
 	.update_plane	= drm_atomic_helper_update_plane,
 	.disable_plane	= drm_atomic_helper_disable_plane,
@@ -213,8 +175,6 @@ static struct drm_plane_funcs exynos_plane_funcs = {
 	.reset		= exynos_drm_plane_reset,
 	.atomic_duplicate_state = exynos_drm_plane_duplicate_state,
 	.atomic_destroy_state = exynos_drm_plane_destroy_state,
-	.atomic_set_property = exynos_drm_plane_atomic_set_property,
-	.atomic_get_property = exynos_drm_plane_atomic_get_property,
 };
 
 static int
@@ -302,20 +262,21 @@ static const struct drm_plane_helper_funcs plane_helper_funcs = {
 };
 
 static void exynos_plane_attach_zpos_property(struct drm_plane *plane,
-					      unsigned int zpos)
+					      unsigned int zpos, bool immutable)
 {
 	struct drm_device *dev = plane->dev;
-	struct exynos_drm_private *dev_priv = dev->dev_private;
 	struct drm_property *prop;
 
-	prop = dev_priv->plane_zpos_property;
-	if (!prop) {
-		prop = drm_property_create_range(dev, 0, "zpos",
-						 0, MAX_PLANE - 1);
-		if (!prop)
-			return;
-
-		dev_priv->plane_zpos_property = prop;
+	if (immutable) {
+		if (!dev->mode_config.zpos_immutable_property)
+			if (!drm_mode_create_zpos_immutable_property(dev))
+				return;
+		prop = dev->mode_config.zpos_immutable_property;
+	} else {
+		if (!dev->mode_config.zpos_property)
+			if (!drm_mode_create_zpos_property(dev))
+				return;
+		prop = dev->mode_config.zpos_property;
 	}
 
 	drm_object_attach_property(&plane->base, prop, zpos);
@@ -344,7 +305,8 @@ int exynos_plane_init(struct drm_device *dev,
 	exynos_plane->index = index;
 	exynos_plane->config = config;
 
-	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos);
+	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos,
+			   !(config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS));
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
index b5fbc1cbf024..6ab68eca0004 100644
--- a/drivers/gpu/drm/exynos/exynos_mixer.c
+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
@@ -34,6 +34,7 @@
 #include <linux/component.h>
 
 #include <drm/exynos_drm.h>
+#include <drm/drm_atomic_helper.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_drm_crtc.h"
@@ -95,6 +96,8 @@ struct mixer_context {
 	struct drm_device	*drm_dev;
 	struct exynos_drm_crtc	*crtc;
 	struct exynos_drm_plane	planes[MIXER_WIN_NR];
+	struct drm_plane	*zpos_planes[MIXER_WIN_NR];
+	int			num_planes;
 	int			pipe;
 	unsigned long		flags;
 	bool			interlace;
@@ -478,6 +481,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
 	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
 	struct mixer_resources *res = &ctx->mixer_res;
 	struct drm_framebuffer *fb = state->base.fb;
+	unsigned int priority = state->base.normalized_zpos + 1;
 	unsigned long flags;
 	dma_addr_t luma_addr[2], chroma_addr[2];
 	bool tiled_mode = false;
@@ -562,7 +566,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
 
 	mixer_cfg_scan(ctx, mode->vdisplay);
 	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
-	mixer_cfg_layer(ctx, plane->index, state->zpos + 1, true);
+	mixer_cfg_layer(ctx, plane->index, priority, true);
 	mixer_cfg_vp_blend(ctx);
 	mixer_run(ctx);
 
@@ -587,6 +591,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
 	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
 	struct mixer_resources *res = &ctx->mixer_res;
 	struct drm_framebuffer *fb = state->base.fb;
+	unsigned int priority = state->base.normalized_zpos + 1;
 	unsigned long flags;
 	unsigned int win = plane->index;
 	unsigned int x_ratio = 0, y_ratio = 0;
@@ -678,7 +683,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
 
 	mixer_cfg_scan(ctx, mode->vdisplay);
 	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
-	mixer_cfg_layer(ctx, win, state->zpos + 1, true);
+	mixer_cfg_layer(ctx, win, priority, true);
 	mixer_cfg_gfx_blend(ctx, win, is_alpha_format(fb->pixel_format));
 
 	/* layer update mandatory for mixer 16.0.33.0 */
@@ -981,6 +986,12 @@ static void mixer_atomic_begin(struct exynos_drm_crtc *crtc)
 	if (!test_bit(MXR_BIT_POWERED, &mixer_ctx->flags))
 		return;
 
+	/*
+	 * Normalizing up to 3 planes is cheap, no need for checking
+	 * if zpos has been really changed.
+	 */
+	drm_atomic_helper_normalize_zpos(mixer_ctx->zpos_planes,
+					 mixer_ctx->num_planes);
 	mixer_vsync_set_update(mixer_ctx, false);
 }
 
@@ -1203,13 +1214,15 @@ static int mixer_bind(struct device *dev, struct device *manager, void *data)
 
 	for (i = 0; i < MIXER_WIN_NR; i++) {
 		if (i == VP_DEFAULT_WIN && !ctx->vp_enabled)
-			continue;
+			break;
 
 		ret = exynos_plane_init(drm_dev, &ctx->planes[i], i,
 					1 << ctx->pipe, &plane_configs[i]);
 		if (ret)
 			return ret;
+		ctx->zpos_planes[i] = &ctx->planes[i].base;
 	}
+	ctx->num_planes = i;
 
 	exynos_plane = &ctx->planes[DEFAULT_WIN];
 	ctx->crtc = exynos_drm_crtc_create(drm_dev, &exynos_plane->base,
-- 
1.9.2

[PATCH v2 3/3] drm: simplify initialization of rotation property

[Marek Szyprowski]

This patch simplifies initialization of generic rotation property and
aligns the code to match recently introduced function for intializing
generic zpos property. It also adds missing documentation.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 10 ++++------
 drivers/gpu/drm/drm_crtc.c                      | 26 +++++++++++++++++++------
 drivers/gpu/drm/i915/intel_display.c            |  6 ++----
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c       |  3 +--
 drivers/gpu/drm/omapdrm/omap_drv.c              |  3 +--
 include/drm/drm_crtc.h                          |  4 ++--
 6 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index 1ffe9c329c46..4f9606cdf0f2 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -967,12 +967,10 @@ atmel_hlcdc_plane_create_properties(struct drm_device *dev)
 	if (!props->alpha)
 		return ERR_PTR(-ENOMEM);
 
-	dev->mode_config.rotation_property =
-			drm_mode_create_rotation_property(dev,
-							  BIT(DRM_ROTATE_0) |
-							  BIT(DRM_ROTATE_90) |
-							  BIT(DRM_ROTATE_180) |
-							  BIT(DRM_ROTATE_270));
+	drm_mode_create_rotation_property(dev, BIT(DRM_ROTATE_0) |
+					       BIT(DRM_ROTATE_90) |
+					       BIT(DRM_ROTATE_180) |
+					       BIT(DRM_ROTATE_270));
 	if (!dev->mode_config.rotation_property)
 		return ERR_PTR(-ENOMEM);
 
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index e33866084b70..890c5925e6db 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -5861,10 +5861,20 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_mode_config_cleanup);
 
-struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
-						       unsigned int supported_rotations)
+/**
+ * drm_mode_create_rotation_property - create generic rotation property
+ * @dev: DRM device
+ * @supported_rotations: bitmask of supported rotation modes
+ *
+ * This function initializes generic rotation property and enables support
+ * for it in drm core. Drivers can then attach this property to planes to enable
+ * support for different rotation modes.
+ */
+int drm_mode_create_rotation_property(struct drm_device *dev,
+				      unsigned int supported_rotations)
 {
-	static const struct drm_prop_enum_list props[] = {
+	struct drm_property *prop;
+	static const struct drm_prop_enum_list values[] = {
 		{ DRM_ROTATE_0,   "rotate-0" },
 		{ DRM_ROTATE_90,  "rotate-90" },
 		{ DRM_ROTATE_180, "rotate-180" },
@@ -5873,9 +5883,13 @@ struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 		{ DRM_REFLECT_Y,  "reflect-y" },
 	};
 
-	return drm_property_create_bitmask(dev, 0, "rotation",
-					   props, ARRAY_SIZE(props),
-					   supported_rotations);
+	prop = drm_property_create_bitmask(dev, 0, "rotation", values,
+				ARRAY_SIZE(values), supported_rotations);
+	if (!prop)
+		return -ENOMEM;
+
+	dev->mode_config.rotation_property = prop;
+	return 0;
 }
 EXPORT_SYMBOL(drm_mode_create_rotation_property);
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 02f6ccb848a9..5b7ba46491a0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14042,8 +14042,7 @@ void intel_create_rotation_property(struct drm_device *dev, struct intel_plane *
 		if (INTEL_INFO(dev)->gen >= 9)
 			flags |= BIT(DRM_ROTATE_90) | BIT(DRM_ROTATE_270);
 
-		dev->mode_config.rotation_property =
-			drm_mode_create_rotation_property(dev, flags);
+		drm_mode_create_rotation_property(dev, flags);
 	}
 	if (dev->mode_config.rotation_property)
 		drm_object_attach_property(&plane->base.base,
@@ -14179,8 +14178,7 @@ static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
 
 	if (INTEL_INFO(dev)->gen >= 4) {
 		if (!dev->mode_config.rotation_property)
-			dev->mode_config.rotation_property =
-				drm_mode_create_rotation_property(dev,
+			drm_mode_create_rotation_property(dev,
 							BIT(DRM_ROTATE_0) |
 							BIT(DRM_ROTATE_180));
 		if (dev->mode_config.rotation_property)
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
index 432c09836b0e..8defeec0d453 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
@@ -76,8 +76,7 @@ static void mdp5_plane_install_rotation_property(struct drm_device *dev,
 		return;
 
 	if (!dev->mode_config.rotation_property)
-		dev->mode_config.rotation_property =
-			drm_mode_create_rotation_property(dev,
+		drm_mode_create_rotation_property(dev,
 			BIT(DRM_REFLECT_X) | BIT(DRM_REFLECT_Y));
 
 	if (dev->mode_config.rotation_property)
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index dfafdb602ad2..c6ce2b31f1c5 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -304,8 +304,7 @@ static int omap_modeset_init_properties(struct drm_device *dev)
 	struct omap_drm_private *priv = dev->dev_private;
 
 	if (priv->has_dmm) {
-		dev->mode_config.rotation_property =
-			drm_mode_create_rotation_property(dev,
+		drm_mode_create_rotation_property(dev,
 				BIT(DRM_ROTATE_0) | BIT(DRM_ROTATE_90) |
 				BIT(DRM_ROTATE_180) | BIT(DRM_ROTATE_270) |
 				BIT(DRM_REFLECT_X) | BIT(DRM_REFLECT_Y));
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 13035e2c5e51..7fe38dc8244a 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -2488,8 +2488,8 @@ extern int drm_format_plane_cpp(uint32_t format, int plane);
 extern int drm_format_horz_chroma_subsampling(uint32_t format);
 extern int drm_format_vert_chroma_subsampling(uint32_t format);
 extern const char *drm_get_format_name(uint32_t format);
-extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
-							      unsigned int supported_rotations);
+extern int drm_mode_create_rotation_property(struct drm_device *dev,
+					     unsigned int supported_rotations);
 extern unsigned int drm_rotation_simplify(unsigned int rotation,
 					  unsigned int supported_rotations);
 
-- 
1.9.2

Re: [PATCH v2 2/3] drm/exynos: use generic code for managing zpos plane property

[Daniel Vetter]

On Mon, Jan 11, 2016 at 12:03:04PM +0100, Marek Szyprowski wrote:
> This patch replaces zpos property handling custom code in Exynos DRM
> driver with calls to generic DRM code.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_drv.h   |  1 -
>  drivers/gpu/drm/exynos/exynos_drm_plane.c | 66 +++++++------------------------
>  drivers/gpu/drm/exynos/exynos_mixer.c     | 19 +++++++--
>  3 files changed, 30 insertions(+), 56 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> index 17b5ded72ff1..244ae6c4482c 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> @@ -217,7 +217,6 @@ struct exynos_drm_private {
>  	 * this array is used to be aware of which crtc did it request vblank.
>  	 */
>  	struct drm_crtc *crtc[MAX_CRTC];
> -	struct drm_property *plane_zpos_property;
>  
>  	unsigned long da_start;
>  	unsigned long da_space_size;
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_plane.c b/drivers/gpu/drm/exynos/exynos_drm_plane.c
> index d86227236f55..ba46bc3de796 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_plane.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_plane.c
> @@ -137,9 +137,9 @@ static void exynos_drm_plane_reset(struct drm_plane *plane)
>  
>  	exynos_state = kzalloc(sizeof(*exynos_state), GFP_KERNEL);
>  	if (exynos_state) {
> -		exynos_state->zpos = exynos_plane->config->zpos;
>  		plane->state = &exynos_state->base;
>  		plane->state->plane = plane;
> +		plane->state->zpos = exynos_plane->config->zpos;
>  	}
>  }
>  
> @@ -155,7 +155,6 @@ exynos_drm_plane_duplicate_state(struct drm_plane *plane)
>  		return NULL;
>  
>  	__drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
> -	copy->zpos = exynos_state->zpos;
>  	return &copy->base;
>  }
>  
> @@ -168,43 +167,6 @@ static void exynos_drm_plane_destroy_state(struct drm_plane *plane,
>  	kfree(old_exynos_state);
>  }
>  
> -static int exynos_drm_plane_atomic_set_property(struct drm_plane *plane,
> -						struct drm_plane_state *state,
> -						struct drm_property *property,
> -						uint64_t val)
> -{
> -	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
> -	struct exynos_drm_plane_state *exynos_state =
> -					to_exynos_plane_state(state);
> -	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
> -	const struct exynos_drm_plane_config *config = exynos_plane->config;
> -
> -	if (property == dev_priv->plane_zpos_property &&
> -	    (config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS))
> -		exynos_state->zpos = val;
> -	else
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
> -static int exynos_drm_plane_atomic_get_property(struct drm_plane *plane,
> -					  const struct drm_plane_state *state,
> -					  struct drm_property *property,
> -					  uint64_t *val)
> -{
> -	const struct exynos_drm_plane_state *exynos_state =
> -		container_of(state, const struct exynos_drm_plane_state, base);
> -	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
> -
> -	if (property == dev_priv->plane_zpos_property)
> -		*val = exynos_state->zpos;
> -	else
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
>  static struct drm_plane_funcs exynos_plane_funcs = {
>  	.update_plane	= drm_atomic_helper_update_plane,
>  	.disable_plane	= drm_atomic_helper_disable_plane,
> @@ -213,8 +175,6 @@ static struct drm_plane_funcs exynos_plane_funcs = {
>  	.reset		= exynos_drm_plane_reset,
>  	.atomic_duplicate_state = exynos_drm_plane_duplicate_state,
>  	.atomic_destroy_state = exynos_drm_plane_destroy_state,
> -	.atomic_set_property = exynos_drm_plane_atomic_set_property,
> -	.atomic_get_property = exynos_drm_plane_atomic_get_property,
>  };
>  
>  static int
> @@ -302,20 +262,21 @@ static const struct drm_plane_helper_funcs plane_helper_funcs = {
>  };
>  
>  static void exynos_plane_attach_zpos_property(struct drm_plane *plane,
> -					      unsigned int zpos)
> +					      unsigned int zpos, bool immutable)
>  {
>  	struct drm_device *dev = plane->dev;
> -	struct exynos_drm_private *dev_priv = dev->dev_private;
>  	struct drm_property *prop;
>  
> -	prop = dev_priv->plane_zpos_property;
> -	if (!prop) {
> -		prop = drm_property_create_range(dev, 0, "zpos",
> -						 0, MAX_PLANE - 1);
> -		if (!prop)
> -			return;
> -
> -		dev_priv->plane_zpos_property = prop;
> +	if (immutable) {
> +		if (!dev->mode_config.zpos_immutable_property)
> +			if (!drm_mode_create_zpos_immutable_property(dev))
> +				return;
> +		prop = dev->mode_config.zpos_immutable_property;
> +	} else {
> +		if (!dev->mode_config.zpos_property)
> +			if (!drm_mode_create_zpos_property(dev))
> +				return;
> +		prop = dev->mode_config.zpos_property;
>  	}
>  
>  	drm_object_attach_property(&plane->base, prop, zpos);
> @@ -344,7 +305,8 @@ int exynos_plane_init(struct drm_device *dev,
>  	exynos_plane->index = index;
>  	exynos_plane->config = config;
>  
> -	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos);
> +	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos,
> +			   !(config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS));
>  
>  	return 0;
>  }
> diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
> index b5fbc1cbf024..6ab68eca0004 100644
> --- a/drivers/gpu/drm/exynos/exynos_mixer.c
> +++ b/drivers/gpu/drm/exynos/exynos_mixer.c
> @@ -34,6 +34,7 @@
>  #include <linux/component.h>
>  
>  #include <drm/exynos_drm.h>
> +#include <drm/drm_atomic_helper.h>
>  
>  #include "exynos_drm_drv.h"
>  #include "exynos_drm_crtc.h"
> @@ -95,6 +96,8 @@ struct mixer_context {
>  	struct drm_device	*drm_dev;
>  	struct exynos_drm_crtc	*crtc;
>  	struct exynos_drm_plane	planes[MIXER_WIN_NR];
> +	struct drm_plane	*zpos_planes[MIXER_WIN_NR];
> +	int			num_planes;
>  	int			pipe;
>  	unsigned long		flags;
>  	bool			interlace;
> @@ -478,6 +481,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
>  	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
>  	struct mixer_resources *res = &ctx->mixer_res;
>  	struct drm_framebuffer *fb = state->base.fb;
> +	unsigned int priority = state->base.normalized_zpos + 1;
>  	unsigned long flags;
>  	dma_addr_t luma_addr[2], chroma_addr[2];
>  	bool tiled_mode = false;
> @@ -562,7 +566,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
>  
>  	mixer_cfg_scan(ctx, mode->vdisplay);
>  	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
> -	mixer_cfg_layer(ctx, plane->index, state->zpos + 1, true);
> +	mixer_cfg_layer(ctx, plane->index, priority, true);
>  	mixer_cfg_vp_blend(ctx);
>  	mixer_run(ctx);
>  
> @@ -587,6 +591,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
>  	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
>  	struct mixer_resources *res = &ctx->mixer_res;
>  	struct drm_framebuffer *fb = state->base.fb;
> +	unsigned int priority = state->base.normalized_zpos + 1;
>  	unsigned long flags;
>  	unsigned int win = plane->index;
>  	unsigned int x_ratio = 0, y_ratio = 0;
> @@ -678,7 +683,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
>  
>  	mixer_cfg_scan(ctx, mode->vdisplay);
>  	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
> -	mixer_cfg_layer(ctx, win, state->zpos + 1, true);
> +	mixer_cfg_layer(ctx, win, priority, true);
>  	mixer_cfg_gfx_blend(ctx, win, is_alpha_format(fb->pixel_format));
>  
>  	/* layer update mandatory for mixer 16.0.33.0 */
> @@ -981,6 +986,12 @@ static void mixer_atomic_begin(struct exynos_drm_crtc *crtc)
>  	if (!test_bit(MXR_BIT_POWERED, &mixer_ctx->flags))
>  		return;
>  
> +	/*
> +	 * Normalizing up to 3 planes is cheap, no need for checking
> +	 * if zpos has been really changed.
> +	 */
> +	drm_atomic_helper_normalize_zpos(mixer_ctx->zpos_planes,
> +					 mixer_ctx->num_planes);

Hm, this is a bit a cumbersome interface for drivers and will make
converting over to the normalized zpos more work. Can't we handle this in
the atomic helpers directly? I'm thinking of the following flow:

- if new_plane_state->zpos != old_plane_state->zpos then set new_crtc_state->zpos_changed
- if new_crtc_state->plane_mask != old_crtc_state->plane_mask ||
  new_crtc_state->zpos_changed then recompute normilized zpos.

Imo that would fit well in drm_atomic_helper_check_planes().

With that bit of additional logic drivers can just use normlized_zpos and
don't need to care about anything really.

Thoughts?
-Daniel

>  	mixer_vsync_set_update(mixer_ctx, false);
>  }
>  
> @@ -1203,13 +1214,15 @@ static int mixer_bind(struct device *dev, struct device *manager, void *data)
>  
>  	for (i = 0; i < MIXER_WIN_NR; i++) {
>  		if (i == VP_DEFAULT_WIN && !ctx->vp_enabled)
> -			continue;
> +			break;
>  
>  		ret = exynos_plane_init(drm_dev, &ctx->planes[i], i,
>  					1 << ctx->pipe, &plane_configs[i]);
>  		if (ret)
>  			return ret;
> +		ctx->zpos_planes[i] = &ctx->planes[i].base;
>  	}
> +	ctx->num_planes = i;
>  
>  	exynos_plane = &ctx->planes[DEFAULT_WIN];
>  	ctx->crtc = exynos_drm_crtc_create(drm_dev, &exynos_plane->base,
> -- 
> 1.9.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH v2 1/3] drm: add generic zpos property

[Daniel Vetter]

On Mon, Jan 11, 2016 at 12:03:03PM +0100, Marek Szyprowski wrote:
> 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 | 45 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc.c          | 47 +++++++++++++++++++++++++++++++++++++
>  include/drm/drm_atomic_helper.h     |  2 ++
>  include/drm/drm_crtc.h              | 12 ++++++++++
>  6 files changed, 122 insertions(+), 2 deletions(-)
> 
> 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
> +		planes' 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..167d32346e2f 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 +2782,47 @@ void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
>  	kfree(state);
>  }
>  EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
> +
> +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. Planes are compared first by their zpos values, then in case
> + * they equal, by plane id. Plane with lowest zpos value is at the bottom.
> + * 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 caller 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..e33866084b70 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -5880,6 +5880,53 @@ struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
>  EXPORT_SYMBOL(drm_mode_create_rotation_property);
>  
>  /**
> + * drm_mode_create_zpos_property - create muttable zpos property
> + * @dev: DRM device
> + *
> + * This function initializes generic muttable zpos property and enables support
> + * for it in drm core. Drivers can then attach this property to planes to enable
> + * support for configurable planes arrangement during blending operation.
> + * Drivers can also use drm_atomic_helper_normalize_zpos() function to calculate
> + * drm_plane_state->normalized_zpos values.

Should also document return value semantics. Same for all the others with
non-void return value. But I have some more thoughts about the helper
interface itself (in reply to patch 2) so maybe that should wait a bit
until that's settled.
-Daniel

> + */
> +int drm_mode_create_zpos_property(struct drm_device *dev)
> +{
> +	struct drm_property *prop;
> +
> +	prop = drm_property_create_range(dev, 0, "zpos", 0, 255);
> +	if (!prop)
> +		return -ENOMEM;
> +
> +	dev->mode_config.zpos_property = prop;
> +	return 0;
> +}
> +EXPORT_SYMBOL(drm_mode_create_zpos_property);
> +
> +/**
> + * drm_plane_create_zpos_property - create immuttable zpos property
> + * @dev: DRM device
> + *
> + * This function initializes generic immuttable zpos property and enables
> + * support for it in drm core. Using this property driver lets userspace
> + * to get the arrangement of the planes for blending operation and notifies
> + * it that the hardware (or driver) doesn't support changing of the planes'
> + * order.
> + */
> +int drm_mode_create_zpos_immutable_property(struct drm_device *dev)
> +{
> +	struct drm_property *prop;
> +
> +	prop = drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "zpos",
> +					 0, 255);
> +	if (!prop)
> +		return -ENOMEM;
> +
> +	dev->mode_config.zpos_immutable_property = prop;
> +	return 0;
> +}
> +EXPORT_SYMBOL(drm_mode_create_zpos_immutable_property);
> +
> +/**
>   * DOC: Tile group
>   *
>   * Tile groups are used to represent tiled monitors with a unique
> 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..13035e2c5e51 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 +2493,9 @@ 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 int drm_mode_create_zpos_property(struct drm_device *dev);
> +extern int drm_mode_create_zpos_immutable_property(struct drm_device *dev);
> +
>  /* Helpers */
>  
>  static inline struct drm_plane *drm_plane_find(struct drm_device *dev,
> -- 
> 1.9.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH v2 2/3] drm/exynos: use generic code for managing zpos plane property

[Marek Szyprowski]

Hello,

On 2016-01-11 16:13, Daniel Vetter wrote:
> On Mon, Jan 11, 2016 at 12:03:04PM +0100, Marek Szyprowski wrote:
>> This patch replaces zpos property handling custom code in Exynos DRM
>> driver with calls to generic DRM code.
>>
>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> ---
>>   drivers/gpu/drm/exynos/exynos_drm_drv.h   |  1 -
>>   drivers/gpu/drm/exynos/exynos_drm_plane.c | 66 +++++++------------------------
>>   drivers/gpu/drm/exynos/exynos_mixer.c     | 19 +++++++--
>>   3 files changed, 30 insertions(+), 56 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
>> index 17b5ded72ff1..244ae6c4482c 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
>> @@ -217,7 +217,6 @@ struct exynos_drm_private {
>>   	 * this array is used to be aware of which crtc did it request vblank.
>>   	 */
>>   	struct drm_crtc *crtc[MAX_CRTC];
>> -	struct drm_property *plane_zpos_property;
>>   
>>   	unsigned long da_start;
>>   	unsigned long da_space_size;
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_plane.c b/drivers/gpu/drm/exynos/exynos_drm_plane.c
>> index d86227236f55..ba46bc3de796 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_plane.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_plane.c
>> @@ -137,9 +137,9 @@ static void exynos_drm_plane_reset(struct drm_plane *plane)
>>   
>>   	exynos_state = kzalloc(sizeof(*exynos_state), GFP_KERNEL);
>>   	if (exynos_state) {
>> -		exynos_state->zpos = exynos_plane->config->zpos;
>>   		plane->state = &exynos_state->base;
>>   		plane->state->plane = plane;
>> +		plane->state->zpos = exynos_plane->config->zpos;
>>   	}
>>   }
>>   
>> @@ -155,7 +155,6 @@ exynos_drm_plane_duplicate_state(struct drm_plane *plane)
>>   		return NULL;
>>   
>>   	__drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
>> -	copy->zpos = exynos_state->zpos;
>>   	return &copy->base;
>>   }
>>   
>> @@ -168,43 +167,6 @@ static void exynos_drm_plane_destroy_state(struct drm_plane *plane,
>>   	kfree(old_exynos_state);
>>   }
>>   
>> -static int exynos_drm_plane_atomic_set_property(struct drm_plane *plane,
>> -						struct drm_plane_state *state,
>> -						struct drm_property *property,
>> -						uint64_t val)
>> -{
>> -	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
>> -	struct exynos_drm_plane_state *exynos_state =
>> -					to_exynos_plane_state(state);
>> -	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
>> -	const struct exynos_drm_plane_config *config = exynos_plane->config;
>> -
>> -	if (property == dev_priv->plane_zpos_property &&
>> -	    (config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS))
>> -		exynos_state->zpos = val;
>> -	else
>> -		return -EINVAL;
>> -
>> -	return 0;
>> -}
>> -
>> -static int exynos_drm_plane_atomic_get_property(struct drm_plane *plane,
>> -					  const struct drm_plane_state *state,
>> -					  struct drm_property *property,
>> -					  uint64_t *val)
>> -{
>> -	const struct exynos_drm_plane_state *exynos_state =
>> -		container_of(state, const struct exynos_drm_plane_state, base);
>> -	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
>> -
>> -	if (property == dev_priv->plane_zpos_property)
>> -		*val = exynos_state->zpos;
>> -	else
>> -		return -EINVAL;
>> -
>> -	return 0;
>> -}
>> -
>>   static struct drm_plane_funcs exynos_plane_funcs = {
>>   	.update_plane	= drm_atomic_helper_update_plane,
>>   	.disable_plane	= drm_atomic_helper_disable_plane,
>> @@ -213,8 +175,6 @@ static struct drm_plane_funcs exynos_plane_funcs = {
>>   	.reset		= exynos_drm_plane_reset,
>>   	.atomic_duplicate_state = exynos_drm_plane_duplicate_state,
>>   	.atomic_destroy_state = exynos_drm_plane_destroy_state,
>> -	.atomic_set_property = exynos_drm_plane_atomic_set_property,
>> -	.atomic_get_property = exynos_drm_plane_atomic_get_property,
>>   };
>>   
>>   static int
>> @@ -302,20 +262,21 @@ static const struct drm_plane_helper_funcs plane_helper_funcs = {
>>   };
>>   
>>   static void exynos_plane_attach_zpos_property(struct drm_plane *plane,
>> -					      unsigned int zpos)
>> +					      unsigned int zpos, bool immutable)
>>   {
>>   	struct drm_device *dev = plane->dev;
>> -	struct exynos_drm_private *dev_priv = dev->dev_private;
>>   	struct drm_property *prop;
>>   
>> -	prop = dev_priv->plane_zpos_property;
>> -	if (!prop) {
>> -		prop = drm_property_create_range(dev, 0, "zpos",
>> -						 0, MAX_PLANE - 1);
>> -		if (!prop)
>> -			return;
>> -
>> -		dev_priv->plane_zpos_property = prop;
>> +	if (immutable) {
>> +		if (!dev->mode_config.zpos_immutable_property)
>> +			if (!drm_mode_create_zpos_immutable_property(dev))
>> +				return;
>> +		prop = dev->mode_config.zpos_immutable_property;
>> +	} else {
>> +		if (!dev->mode_config.zpos_property)
>> +			if (!drm_mode_create_zpos_property(dev))
>> +				return;
>> +		prop = dev->mode_config.zpos_property;
>>   	}
>>   
>>   	drm_object_attach_property(&plane->base, prop, zpos);
>> @@ -344,7 +305,8 @@ int exynos_plane_init(struct drm_device *dev,
>>   	exynos_plane->index = index;
>>   	exynos_plane->config = config;
>>   
>> -	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos);
>> +	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos,
>> +			   !(config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS));
>>   
>>   	return 0;
>>   }
>> diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
>> index b5fbc1cbf024..6ab68eca0004 100644
>> --- a/drivers/gpu/drm/exynos/exynos_mixer.c
>> +++ b/drivers/gpu/drm/exynos/exynos_mixer.c
>> @@ -34,6 +34,7 @@
>>   #include <linux/component.h>
>>   
>>   #include <drm/exynos_drm.h>
>> +#include <drm/drm_atomic_helper.h>
>>   
>>   #include "exynos_drm_drv.h"
>>   #include "exynos_drm_crtc.h"
>> @@ -95,6 +96,8 @@ struct mixer_context {
>>   	struct drm_device	*drm_dev;
>>   	struct exynos_drm_crtc	*crtc;
>>   	struct exynos_drm_plane	planes[MIXER_WIN_NR];
>> +	struct drm_plane	*zpos_planes[MIXER_WIN_NR];
>> +	int			num_planes;
>>   	int			pipe;
>>   	unsigned long		flags;
>>   	bool			interlace;
>> @@ -478,6 +481,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
>>   	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
>>   	struct mixer_resources *res = &ctx->mixer_res;
>>   	struct drm_framebuffer *fb = state->base.fb;
>> +	unsigned int priority = state->base.normalized_zpos + 1;
>>   	unsigned long flags;
>>   	dma_addr_t luma_addr[2], chroma_addr[2];
>>   	bool tiled_mode = false;
>> @@ -562,7 +566,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
>>   
>>   	mixer_cfg_scan(ctx, mode->vdisplay);
>>   	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
>> -	mixer_cfg_layer(ctx, plane->index, state->zpos + 1, true);
>> +	mixer_cfg_layer(ctx, plane->index, priority, true);
>>   	mixer_cfg_vp_blend(ctx);
>>   	mixer_run(ctx);
>>   
>> @@ -587,6 +591,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
>>   	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
>>   	struct mixer_resources *res = &ctx->mixer_res;
>>   	struct drm_framebuffer *fb = state->base.fb;
>> +	unsigned int priority = state->base.normalized_zpos + 1;
>>   	unsigned long flags;
>>   	unsigned int win = plane->index;
>>   	unsigned int x_ratio = 0, y_ratio = 0;
>> @@ -678,7 +683,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
>>   
>>   	mixer_cfg_scan(ctx, mode->vdisplay);
>>   	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
>> -	mixer_cfg_layer(ctx, win, state->zpos + 1, true);
>> +	mixer_cfg_layer(ctx, win, priority, true);
>>   	mixer_cfg_gfx_blend(ctx, win, is_alpha_format(fb->pixel_format));
>>   
>>   	/* layer update mandatory for mixer 16.0.33.0 */
>> @@ -981,6 +986,12 @@ static void mixer_atomic_begin(struct exynos_drm_crtc *crtc)
>>   	if (!test_bit(MXR_BIT_POWERED, &mixer_ctx->flags))
>>   		return;
>>   
>> +	/*
>> +	 * Normalizing up to 3 planes is cheap, no need for checking
>> +	 * if zpos has been really changed.
>> +	 */
>> +	drm_atomic_helper_normalize_zpos(mixer_ctx->zpos_planes,
>> +					 mixer_ctx->num_planes);
> Hm, this is a bit a cumbersome interface for drivers and will make
> converting over to the normalized zpos more work. Can't we handle this in
> the atomic helpers directly? I'm thinking of the following flow:
>
> - if new_plane_state->zpos != old_plane_state->zpos then set new_crtc_state->zpos_changed
> - if new_crtc_state->plane_mask != old_crtc_state->plane_mask ||
>    new_crtc_state->zpos_changed then recompute normilized zpos.
>
> Imo that would fit well in drm_atomic_helper_check_planes().
>
> With that bit of additional logic drivers can just use normlized_zpos and
> don't need to care about anything really.

Okay, I will try to implement this logic.


Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH v2 2/3] drm/exynos: use generic code for managing zpos plane property

[Daniel Vetter]

On Tue, Jan 12, 2016 at 10:34:27AM +0100, Marek Szyprowski wrote:
> Hello,
> 
> On 2016-01-11 16:13, Daniel Vetter wrote:
> >On Mon, Jan 11, 2016 at 12:03:04PM +0100, Marek Szyprowski wrote:
> >>This patch replaces zpos property handling custom code in Exynos DRM
> >>driver with calls to generic DRM code.
> >>
> >>Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> >>---
> >>  drivers/gpu/drm/exynos/exynos_drm_drv.h   |  1 -
> >>  drivers/gpu/drm/exynos/exynos_drm_plane.c | 66 +++++++------------------------
> >>  drivers/gpu/drm/exynos/exynos_mixer.c     | 19 +++++++--
> >>  3 files changed, 30 insertions(+), 56 deletions(-)
> >>
> >>diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> >>index 17b5ded72ff1..244ae6c4482c 100644
> >>--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
> >>+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
> >>@@ -217,7 +217,6 @@ struct exynos_drm_private {
> >>  	 * this array is used to be aware of which crtc did it request vblank.
> >>  	 */
> >>  	struct drm_crtc *crtc[MAX_CRTC];
> >>-	struct drm_property *plane_zpos_property;
> >>  	unsigned long da_start;
> >>  	unsigned long da_space_size;
> >>diff --git a/drivers/gpu/drm/exynos/exynos_drm_plane.c b/drivers/gpu/drm/exynos/exynos_drm_plane.c
> >>index d86227236f55..ba46bc3de796 100644
> >>--- a/drivers/gpu/drm/exynos/exynos_drm_plane.c
> >>+++ b/drivers/gpu/drm/exynos/exynos_drm_plane.c
> >>@@ -137,9 +137,9 @@ static void exynos_drm_plane_reset(struct drm_plane *plane)
> >>  	exynos_state = kzalloc(sizeof(*exynos_state), GFP_KERNEL);
> >>  	if (exynos_state) {
> >>-		exynos_state->zpos = exynos_plane->config->zpos;
> >>  		plane->state = &exynos_state->base;
> >>  		plane->state->plane = plane;
> >>+		plane->state->zpos = exynos_plane->config->zpos;
> >>  	}
> >>  }
> >>@@ -155,7 +155,6 @@ exynos_drm_plane_duplicate_state(struct drm_plane *plane)
> >>  		return NULL;
> >>  	__drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
> >>-	copy->zpos = exynos_state->zpos;
> >>  	return &copy->base;
> >>  }
> >>@@ -168,43 +167,6 @@ static void exynos_drm_plane_destroy_state(struct drm_plane *plane,
> >>  	kfree(old_exynos_state);
> >>  }
> >>-static int exynos_drm_plane_atomic_set_property(struct drm_plane *plane,
> >>-						struct drm_plane_state *state,
> >>-						struct drm_property *property,
> >>-						uint64_t val)
> >>-{
> >>-	struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
> >>-	struct exynos_drm_plane_state *exynos_state =
> >>-					to_exynos_plane_state(state);
> >>-	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
> >>-	const struct exynos_drm_plane_config *config = exynos_plane->config;
> >>-
> >>-	if (property == dev_priv->plane_zpos_property &&
> >>-	    (config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS))
> >>-		exynos_state->zpos = val;
> >>-	else
> >>-		return -EINVAL;
> >>-
> >>-	return 0;
> >>-}
> >>-
> >>-static int exynos_drm_plane_atomic_get_property(struct drm_plane *plane,
> >>-					  const struct drm_plane_state *state,
> >>-					  struct drm_property *property,
> >>-					  uint64_t *val)
> >>-{
> >>-	const struct exynos_drm_plane_state *exynos_state =
> >>-		container_of(state, const struct exynos_drm_plane_state, base);
> >>-	struct exynos_drm_private *dev_priv = plane->dev->dev_private;
> >>-
> >>-	if (property == dev_priv->plane_zpos_property)
> >>-		*val = exynos_state->zpos;
> >>-	else
> >>-		return -EINVAL;
> >>-
> >>-	return 0;
> >>-}
> >>-
> >>  static struct drm_plane_funcs exynos_plane_funcs = {
> >>  	.update_plane	= drm_atomic_helper_update_plane,
> >>  	.disable_plane	= drm_atomic_helper_disable_plane,
> >>@@ -213,8 +175,6 @@ static struct drm_plane_funcs exynos_plane_funcs = {
> >>  	.reset		= exynos_drm_plane_reset,
> >>  	.atomic_duplicate_state = exynos_drm_plane_duplicate_state,
> >>  	.atomic_destroy_state = exynos_drm_plane_destroy_state,
> >>-	.atomic_set_property = exynos_drm_plane_atomic_set_property,
> >>-	.atomic_get_property = exynos_drm_plane_atomic_get_property,
> >>  };
> >>  static int
> >>@@ -302,20 +262,21 @@ static const struct drm_plane_helper_funcs plane_helper_funcs = {
> >>  };
> >>  static void exynos_plane_attach_zpos_property(struct drm_plane *plane,
> >>-					      unsigned int zpos)
> >>+					      unsigned int zpos, bool immutable)
> >>  {
> >>  	struct drm_device *dev = plane->dev;
> >>-	struct exynos_drm_private *dev_priv = dev->dev_private;
> >>  	struct drm_property *prop;
> >>-	prop = dev_priv->plane_zpos_property;
> >>-	if (!prop) {
> >>-		prop = drm_property_create_range(dev, 0, "zpos",
> >>-						 0, MAX_PLANE - 1);
> >>-		if (!prop)
> >>-			return;
> >>-
> >>-		dev_priv->plane_zpos_property = prop;
> >>+	if (immutable) {
> >>+		if (!dev->mode_config.zpos_immutable_property)
> >>+			if (!drm_mode_create_zpos_immutable_property(dev))
> >>+				return;
> >>+		prop = dev->mode_config.zpos_immutable_property;
> >>+	} else {
> >>+		if (!dev->mode_config.zpos_property)
> >>+			if (!drm_mode_create_zpos_property(dev))
> >>+				return;
> >>+		prop = dev->mode_config.zpos_property;
> >>  	}
> >>  	drm_object_attach_property(&plane->base, prop, zpos);
> >>@@ -344,7 +305,8 @@ int exynos_plane_init(struct drm_device *dev,
> >>  	exynos_plane->index = index;
> >>  	exynos_plane->config = config;
> >>-	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos);
> >>+	exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos,
> >>+			   !(config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS));
> >>  	return 0;
> >>  }
> >>diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
> >>index b5fbc1cbf024..6ab68eca0004 100644
> >>--- a/drivers/gpu/drm/exynos/exynos_mixer.c
> >>+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
> >>@@ -34,6 +34,7 @@
> >>  #include <linux/component.h>
> >>  #include <drm/exynos_drm.h>
> >>+#include <drm/drm_atomic_helper.h>
> >>  #include "exynos_drm_drv.h"
> >>  #include "exynos_drm_crtc.h"
> >>@@ -95,6 +96,8 @@ struct mixer_context {
> >>  	struct drm_device	*drm_dev;
> >>  	struct exynos_drm_crtc	*crtc;
> >>  	struct exynos_drm_plane	planes[MIXER_WIN_NR];
> >>+	struct drm_plane	*zpos_planes[MIXER_WIN_NR];
> >>+	int			num_planes;
> >>  	int			pipe;
> >>  	unsigned long		flags;
> >>  	bool			interlace;
> >>@@ -478,6 +481,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
> >>  	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
> >>  	struct mixer_resources *res = &ctx->mixer_res;
> >>  	struct drm_framebuffer *fb = state->base.fb;
> >>+	unsigned int priority = state->base.normalized_zpos + 1;
> >>  	unsigned long flags;
> >>  	dma_addr_t luma_addr[2], chroma_addr[2];
> >>  	bool tiled_mode = false;
> >>@@ -562,7 +566,7 @@ static void vp_video_buffer(struct mixer_context *ctx,
> >>  	mixer_cfg_scan(ctx, mode->vdisplay);
> >>  	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
> >>-	mixer_cfg_layer(ctx, plane->index, state->zpos + 1, true);
> >>+	mixer_cfg_layer(ctx, plane->index, priority, true);
> >>  	mixer_cfg_vp_blend(ctx);
> >>  	mixer_run(ctx);
> >>@@ -587,6 +591,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
> >>  	struct drm_display_mode *mode = &state->base.crtc->state->adjusted_mode;
> >>  	struct mixer_resources *res = &ctx->mixer_res;
> >>  	struct drm_framebuffer *fb = state->base.fb;
> >>+	unsigned int priority = state->base.normalized_zpos + 1;
> >>  	unsigned long flags;
> >>  	unsigned int win = plane->index;
> >>  	unsigned int x_ratio = 0, y_ratio = 0;
> >>@@ -678,7 +683,7 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
> >>  	mixer_cfg_scan(ctx, mode->vdisplay);
> >>  	mixer_cfg_rgb_fmt(ctx, mode->vdisplay);
> >>-	mixer_cfg_layer(ctx, win, state->zpos + 1, true);
> >>+	mixer_cfg_layer(ctx, win, priority, true);
> >>  	mixer_cfg_gfx_blend(ctx, win, is_alpha_format(fb->pixel_format));
> >>  	/* layer update mandatory for mixer 16.0.33.0 */
> >>@@ -981,6 +986,12 @@ static void mixer_atomic_begin(struct exynos_drm_crtc *crtc)
> >>  	if (!test_bit(MXR_BIT_POWERED, &mixer_ctx->flags))
> >>  		return;
> >>+	/*
> >>+	 * Normalizing up to 3 planes is cheap, no need for checking
> >>+	 * if zpos has been really changed.
> >>+	 */
> >>+	drm_atomic_helper_normalize_zpos(mixer_ctx->zpos_planes,
> >>+					 mixer_ctx->num_planes);
> >Hm, this is a bit a cumbersome interface for drivers and will make
> >converting over to the normalized zpos more work. Can't we handle this in
> >the atomic helpers directly? I'm thinking of the following flow:
> >
> >- if new_plane_state->zpos != old_plane_state->zpos then set new_crtc_state->zpos_changed
> >- if new_crtc_state->plane_mask != old_crtc_state->plane_mask ||
> >   new_crtc_state->zpos_changed then recompute normilized zpos.
> >
> >Imo that would fit well in drm_atomic_helper_check_planes().
> >
> >With that bit of additional logic drivers can just use normlized_zpos and
> >don't need to care about anything really.
> 
> Okay, I will try to implement this logic.

Just to avoid another respin: If you do so I think it still makes sense to
export the current set of functions, for drivers which don't use helpers
or need to figure out the normalized zpos earlier or whatever.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch