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authorMaxime Ripard <maxime.ripard@bootlin.com>2018-04-11 10:39:25 +0300
committerMaxime Ripard <maxime.ripard@bootlin.com>2018-04-16 22:17:29 +0300
commitae0e28265e216dad11d4cbde42fc15e92919af78 (patch)
tree08e84813756efaadf64b1be7ae953f62fb4a8a4f /drivers/gpu/drm/drm_blend.c
parenta08fc7c8056e75b08285a2ad955228002dcd86bc (diff)
downloadlinux-ae0e28265e216dad11d4cbde42fc15e92919af78.tar.xz
drm/blend: Add a generic alpha property
Some drivers duplicate the logic to create a property to store a per-plane alpha. This is especially useful if we ever want to support extra protocols for Wayland like: https://lists.freedesktop.org/archives/wayland-devel/2017-August/034741.html Let's create a helper in order to move that to the core. Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Acked-by: Sean Paul <seanpaul@chromium.org> Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Link: https://patchwork.freedesktop.org/patch/msgid/6e1ce0db78fcfc407e94913c64819e65109d034d.1523432341.git-series.maxime.ripard@bootlin.com
Diffstat (limited to 'drivers/gpu/drm/drm_blend.c')
-rw-r--r--drivers/gpu/drm/drm_blend.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index 5a81e1b4c076..a16a74d7e15e 100644
--- a/drivers/gpu/drm/drm_blend.c
+++ b/drivers/gpu/drm/drm_blend.c
@@ -88,6 +88,13 @@
* On top of this basic transformation additional properties can be exposed by
* the driver:
*
+ * alpha:
+ * Alpha is setup with drm_plane_create_alpha_property(). It controls the
+ * plane-wide opacity, from transparent (0) to opaque (0xffff). It can be
+ * combined with pixel alpha.
+ * The pixel values in the framebuffers are expected to not be
+ * pre-multiplied by the global alpha associated to the plane.
+ *
* rotation:
* Rotation is set up with drm_plane_create_rotation_property(). It adds a
* rotation and reflection step between the source and destination rectangles.
@@ -106,6 +113,38 @@
*/
/**
+ * drm_plane_create_alpha_property - create a new alpha property
+ * @plane: drm plane
+ *
+ * This function creates a generic, mutable, alpha property and enables support
+ * for it in the DRM core. It is attached to @plane.
+ *
+ * The alpha property will be allowed to be within the bounds of 0
+ * (transparent) to 0xffff (opaque).
+ *
+ * Returns:
+ * 0 on success, negative error code on failure.
+ */
+int drm_plane_create_alpha_property(struct drm_plane *plane)
+{
+ struct drm_property *prop;
+
+ prop = drm_property_create_range(plane->dev, 0, "alpha",
+ 0, DRM_BLEND_ALPHA_OPAQUE);
+ if (!prop)
+ return -ENOMEM;
+
+ drm_object_attach_property(&plane->base, prop, DRM_BLEND_ALPHA_OPAQUE);
+ plane->alpha_property = prop;
+
+ if (plane->state)
+ plane->state->alpha = DRM_BLEND_ALPHA_OPAQUE;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_plane_create_alpha_property);
+
+/**
* drm_plane_create_rotation_property - create a new rotation property
* @plane: drm plane
* @rotation: initial value of the rotation property