1 files changed, 246 insertions, 25 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 4943cef178be..847539645558 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -260,9 +260,7 @@ int drm_connector_init(struct drm_device *dev,
 
 	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL &&
 	    connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
-		drm_object_attach_property(&connector->base,
-					      config->edid_property,
-					      0);
+		drm_connector_attach_edid_property(connector);
 
 	drm_object_attach_property(&connector->base,
 				      config->dpms_property, 0);
@@ -295,6 +293,24 @@ out_put:
 EXPORT_SYMBOL(drm_connector_init);
 
 /**
+ * drm_connector_attach_edid_property - attach edid property.
+ * @connector: the connector
+ *
+ * Some connector types like DRM_MODE_CONNECTOR_VIRTUAL do not get a
+ * edid property attached by default.  This function can be used to
+ * explicitly enable the edid property in these cases.
+ */
+void drm_connector_attach_edid_property(struct drm_connector *connector)
+{
+	struct drm_mode_config *config = &connector->dev->mode_config;
+
+	drm_object_attach_property(&connector->base,
+				   config->edid_property,
+				   0);
+}
+EXPORT_SYMBOL(drm_connector_attach_edid_property);
+
+/**
  * drm_connector_attach_encoder - attach a connector to an encoder
  * @connector: connector to attach
  * @encoder: encoder to attach @connector to
@@ -916,6 +932,13 @@ DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
  *	  is no longer protected and userspace should take appropriate action
  *	  (whatever that might be).
  *
+ * max bpc:
+ *	This range property is used by userspace to limit the bit depth. When
+ *	used the driver would limit the bpc in accordance with the valid range
+ *	supported by the hardware and sink. Drivers to use the function
+ *	drm_connector_attach_max_bpc_property() to create and attach the
+ *	property to the connector during initialization.
+ *
  * Connectors also have one standardized atomic property:
  *
  * CRTC_ID:
@@ -1115,7 +1138,71 @@ void drm_hdmi_avi_infoframe_content_type(struct hdmi_avi_infoframe *frame,
 EXPORT_SYMBOL(drm_hdmi_avi_infoframe_content_type);
 
 /**
- * drm_create_tv_properties - create TV specific connector properties
+ * drm_mode_attach_tv_margin_properties - attach TV connector margin properties
+ * @connector: DRM connector
+ *
+ * Called by a driver when it needs to attach TV margin props to a connector.
+ * Typically used on SDTV and HDMI connectors.
+ */
+void drm_connector_attach_tv_margin_properties(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.tv_left_margin_property,
+				   0);
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.tv_right_margin_property,
+				   0);
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.tv_top_margin_property,
+				   0);
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.tv_bottom_margin_property,
+				   0);
+}
+EXPORT_SYMBOL(drm_connector_attach_tv_margin_properties);
+
+/**
+ * drm_mode_create_tv_margin_properties - create TV connector margin properties
+ * @dev: DRM device
+ *
+ * Called by a driver's HDMI connector initialization routine, this function
+ * creates the TV margin properties for a given device. No need to call this
+ * function for an SDTV connector, it's already called from
+ * drm_mode_create_tv_properties().
+ */
+int drm_mode_create_tv_margin_properties(struct drm_device *dev)
+{
+	if (dev->mode_config.tv_left_margin_property)
+		return 0;
+
+	dev->mode_config.tv_left_margin_property =
+		drm_property_create_range(dev, 0, "left margin", 0, 100);
+	if (!dev->mode_config.tv_left_margin_property)
+		return -ENOMEM;
+
+	dev->mode_config.tv_right_margin_property =
+		drm_property_create_range(dev, 0, "right margin", 0, 100);
+	if (!dev->mode_config.tv_right_margin_property)
+		return -ENOMEM;
+
+	dev->mode_config.tv_top_margin_property =
+		drm_property_create_range(dev, 0, "top margin", 0, 100);
+	if (!dev->mode_config.tv_top_margin_property)
+		return -ENOMEM;
+
+	dev->mode_config.tv_bottom_margin_property =
+		drm_property_create_range(dev, 0, "bottom margin", 0, 100);
+	if (!dev->mode_config.tv_bottom_margin_property)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_mode_create_tv_margin_properties);
+
+/**
+ * drm_mode_create_tv_properties - create TV specific connector properties
  * @dev: DRM device
  * @num_modes: number of different TV formats (modes) supported
  * @modes: array of pointers to strings containing name of each format
@@ -1160,24 +1247,7 @@ int drm_mode_create_tv_properties(struct drm_device *dev,
 	/*
 	 * Other, TV specific properties: margins & TV modes.
 	 */
-	dev->mode_config.tv_left_margin_property =
-		drm_property_create_range(dev, 0, "left margin", 0, 100);
-	if (!dev->mode_config.tv_left_margin_property)
-		goto nomem;
-
-	dev->mode_config.tv_right_margin_property =
-		drm_property_create_range(dev, 0, "right margin", 0, 100);
-	if (!dev->mode_config.tv_right_margin_property)
-		goto nomem;
-
-	dev->mode_config.tv_top_margin_property =
-		drm_property_create_range(dev, 0, "top margin", 0, 100);
-	if (!dev->mode_config.tv_top_margin_property)
-		goto nomem;
-
-	dev->mode_config.tv_bottom_margin_property =
-		drm_property_create_range(dev, 0, "bottom margin", 0, 100);
-	if (!dev->mode_config.tv_bottom_margin_property)
+	if (drm_mode_create_tv_margin_properties(dev))
 		goto nomem;
 
 	dev->mode_config.tv_mode_property =
@@ -1256,6 +1326,105 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev)
 EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
 
 /**
+ * DOC: Variable refresh properties
+ *
+ * Variable refresh rate capable displays can dynamically adjust their
+ * refresh rate by extending the duration of their vertical front porch
+ * until page flip or timeout occurs. This can reduce or remove stuttering
+ * and latency in scenarios where the page flip does not align with the
+ * vblank interval.
+ *
+ * An example scenario would be an application flipping at a constant rate
+ * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank
+ * interval and the same contents will be displayed twice. This can be
+ * observed as stuttering for content with motion.
+ *
+ * If variable refresh rate was active on a display that supported a
+ * variable refresh range from 35Hz to 60Hz no stuttering would be observable
+ * for the example scenario. The minimum supported variable refresh rate of
+ * 35Hz is below the page flip frequency and the vertical front porch can
+ * be extended until the page flip occurs. The vblank interval will be
+ * directly aligned to the page flip rate.
+ *
+ * Not all userspace content is suitable for use with variable refresh rate.
+ * Large and frequent changes in vertical front porch duration may worsen
+ * perceived stuttering for input sensitive applications.
+ *
+ * Panel brightness will also vary with vertical front porch duration. Some
+ * panels may have noticeable differences in brightness between the minimum
+ * vertical front porch duration and the maximum vertical front porch duration.
+ * Large and frequent changes in vertical front porch duration may produce
+ * observable flickering for such panels.
+ *
+ * Userspace control for variable refresh rate is supported via properties
+ * on the &drm_connector and &drm_crtc objects.
+ *
+ * "vrr_capable":
+ *	Optional &drm_connector boolean property that drivers should attach
+ *	with drm_connector_attach_vrr_capable_property() on connectors that
+ *	could support variable refresh rates. Drivers should update the
+ *	property value by calling drm_connector_set_vrr_capable_property().
+ *
+ *	Absence of the property should indicate absence of support.
+ *
+ * "vrr_enabled":
+ *	Default &drm_crtc boolean property that notifies the driver that the
+ *	content on the CRTC is suitable for variable refresh rate presentation.
+ *	The driver will take this property as a hint to enable variable
+ *	refresh rate support if the receiver supports it, ie. if the
+ *	"vrr_capable" property is true on the &drm_connector object. The
+ *	vertical front porch duration will be extended until page-flip or
+ *	timeout when enabled.
+ *
+ *	The minimum vertical front porch duration is defined as the vertical
+ *	front porch duration for the current mode.
+ *
+ *	The maximum vertical front porch duration is greater than or equal to
+ *	the minimum vertical front porch duration. The duration is derived
+ *	from the minimum supported variable refresh rate for the connector.
+ *
+ *	The driver may place further restrictions within these minimum
+ *	and maximum bounds.
+ *
+ *	The semantics for the vertical blank timestamp differ when
+ *	variable refresh rate is active. The vertical blank timestamp
+ *	is defined to be an estimate using the current mode's fixed
+ *	refresh rate timings. The semantics for the page-flip event
+ *	timestamp remain the same.
+ */
+
+/**
+ * drm_connector_attach_vrr_capable_property - creates the
+ * vrr_capable property
+ * @connector: connector to create the vrr_capable property on.
+ *
+ * This is used by atomic drivers to add support for querying
+ * variable refresh rate capability for a connector.
+ *
+ * Returns:
+ * Zero on success, negative errono on failure.
+ */
+int drm_connector_attach_vrr_capable_property(
+	struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop;
+
+	if (!connector->vrr_capable_property) {
+		prop = drm_property_create_bool(dev, DRM_MODE_PROP_IMMUTABLE,
+			"vrr_capable");
+		if (!prop)
+			return -ENOMEM;
+
+		connector->vrr_capable_property = prop;
+		drm_object_attach_property(&connector->base, prop, 0);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_vrr_capable_property);
+
+/**
  * drm_connector_attach_scaling_mode_property - attach atomic scaling mode property
  * @connector: connector to attach scaling mode property on.
  * @scaling_mode_mask: or'ed mask of BIT(%DRM_MODE_SCALE_\*).
@@ -1584,6 +1753,58 @@ void drm_connector_set_link_status_property(struct drm_connector *connector,
 EXPORT_SYMBOL(drm_connector_set_link_status_property);
 
 /**
+ * drm_connector_attach_max_bpc_property - attach "max bpc" property
+ * @connector: connector to attach max bpc property on.
+ * @min: The minimum bit depth supported by the connector.
+ * @max: The maximum bit depth supported by the connector.
+ *
+ * This is used to add support for limiting the bit depth on a connector.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
+					  int min, int max)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop;
+
+	prop = connector->max_bpc_property;
+	if (!prop) {
+		prop = drm_property_create_range(dev, 0, "max bpc", min, max);
+		if (!prop)
+			return -ENOMEM;
+
+		connector->max_bpc_property = prop;
+	}
+
+	drm_object_attach_property(&connector->base, prop, max);
+	connector->state->max_requested_bpc = max;
+	connector->state->max_bpc = max;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
+
+/**
+ * drm_connector_set_vrr_capable_property - sets the variable refresh rate
+ * capable property for a connector
+ * @connector: drm connector
+ * @capable: True if the connector is variable refresh rate capable
+ *
+ * Should be used by atomic drivers to update the indicated support for
+ * variable refresh rate over a connector.
+ */
+void drm_connector_set_vrr_capable_property(
+		struct drm_connector *connector, bool capable)
+{
+	drm_object_property_set_value(&connector->base,
+				      connector->vrr_capable_property,
+				      capable);
+}
+EXPORT_SYMBOL(drm_connector_set_vrr_capable_property);
+
+/**
  * drm_connector_init_panel_orientation_property -
  *	initialize the connecters panel_orientation property
  * @connector: connector for which to init the panel-orientation property.
@@ -1903,7 +2124,7 @@ EXPORT_SYMBOL(drm_mode_get_tile_group);
  * identifier for the tile group.
  *
  * RETURNS:
- * new tile group or error.
+ * new tile group or NULL.
  */
 struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
 						  char topology[8])
@@ -1913,7 +2134,7 @@ struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
 
 	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
 	if (!tg)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	kref_init(&tg->refcount);
 	memcpy(tg->group_data, topology, 8);
@@ -1925,7 +2146,7 @@ struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
 		tg->id = ret;
 	} else {
 		kfree(tg);
-		tg = ERR_PTR(ret);
+		tg = NULL;
 	}
 
 	mutex_unlock(&dev->mode_config.idr_mutex);