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Diffstat (limited to 'drivers/gpu/drm/drm_plane.c')
-rw-r--r--drivers/gpu/drm/drm_plane.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 672c655c7a..57662a1fd3 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -140,6 +140,25 @@
* DRM_FORMAT_MOD_LINEAR. Before linux kernel release v5.1 there have been
* various bugs in this area with inconsistencies between the capability
* flag and per-plane properties.
+ *
+ * SIZE_HINTS:
+ * Blob property which contains the set of recommended plane size
+ * which can used for simple "cursor like" use cases (eg. no scaling).
+ * Using these hints frees userspace from extensive probing of
+ * supported plane sizes through atomic/setcursor ioctls.
+ *
+ * The blob contains an array of struct drm_plane_size_hint, in
+ * order of preference. For optimal usage userspace should pick
+ * the first size that satisfies its own requirements.
+ *
+ * Drivers should only attach this property to planes that
+ * support a very limited set of sizes.
+ *
+ * Note that property value 0 (ie. no blob) is reserved for potential
+ * future use. Current userspace is expected to ignore the property
+ * if the value is 0, and fall back to some other means (eg.
+ * &DRM_CAP_CURSOR_WIDTH and &DRM_CAP_CURSOR_HEIGHT) to determine
+ * the appropriate plane size to use.
*/
static unsigned int drm_num_planes(struct drm_device *dev)
@@ -1729,3 +1748,40 @@ int drm_plane_create_scaling_filter_property(struct drm_plane *plane,
return 0;
}
EXPORT_SYMBOL(drm_plane_create_scaling_filter_property);
+
+/**
+ * drm_plane_add_size_hints_property - create a size hints property
+ *
+ * @plane: drm plane
+ * @hints: size hints
+ * @num_hints: number of size hints
+ *
+ * Create a size hints property for the plane.
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+int drm_plane_add_size_hints_property(struct drm_plane *plane,
+ const struct drm_plane_size_hint *hints,
+ int num_hints)
+{
+ struct drm_device *dev = plane->dev;
+ struct drm_mode_config *config = &dev->mode_config;
+ struct drm_property_blob *blob;
+
+ /* extending to other plane types needs actual thought */
+ if (drm_WARN_ON(dev, plane->type != DRM_PLANE_TYPE_CURSOR))
+ return -EINVAL;
+
+ blob = drm_property_create_blob(dev,
+ array_size(sizeof(hints[0]), num_hints),
+ hints);
+ if (IS_ERR(blob))
+ return PTR_ERR(blob);
+
+ drm_object_attach_property(&plane->base, config->size_hints_property,
+ blob->base.id);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_plane_add_size_hints_property);