drm/connector: add CEC-related fields

As a preparation to adding HDMI CEC helper code, add CEC-related fields
to the struct drm_connector. The callbacks abstract CEC infrastructure
in order to support CEC adapters and CEC notifiers in a universal way.

CEC data is a void pointer as it allows us to make CEC data
helper-specific. For example, currently it will be either cec_notifier
or cec_adapter + drm_connector_hdmi_cec_funcs. Later cec-pin might store
platform callbacks here. DP CEC might need to store AUX pointer, etc.

Signed-off-by: Dmitry Baryshkov <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

drivers/gpu/drm/drm_connector.c

···
 	INIT_LIST_HEAD(&connector->probed_modes);
 	INIT_LIST_HEAD(&connector->modes);
 	mutex_init(&connector->mutex);
+	mutex_init(&connector->cec.mutex);
 	mutex_init(&connector->eld_mutex);
 	mutex_init(&connector->edid_override_mutex);
 	mutex_init(&connector->hdmi.infoframes.lock);
···
 	list_del(&mode->head);
 	drm_mode_destroy(connector->dev, mode);
 }
+
+/**
+ * drm_connector_cec_phys_addr_invalidate - invalidate CEC physical address
+ * @connector: connector undergoing CEC operation
+ *
+ * Invalidated CEC physical address set for this DRM connector.
+ */
+void drm_connector_cec_phys_addr_invalidate(struct drm_connector *connector)
+{
+	mutex_lock(&connector->cec.mutex);
+
+	if (connector->cec.funcs &&
+	    connector->cec.funcs->phys_addr_invalidate)
+		connector->cec.funcs->phys_addr_invalidate(connector);
+
+	mutex_unlock(&connector->cec.mutex);
+}
+EXPORT_SYMBOL(drm_connector_cec_phys_addr_invalidate);
+
+/**
+ * drm_connector_cec_phys_addr_set - propagate CEC physical address
+ * @connector: connector undergoing CEC operation
+ *
+ * Propagate CEC physical address from the display_info to this DRM connector.
+ */
+void drm_connector_cec_phys_addr_set(struct drm_connector *connector)
+{
+	u16 addr;
+
+	mutex_lock(&connector->cec.mutex);
+
+	addr = connector->display_info.source_physical_address;
+
+	if (connector->cec.funcs &&
+	    connector->cec.funcs->phys_addr_set)
+		connector->cec.funcs->phys_addr_set(connector, addr);
+
+	mutex_unlock(&connector->cec.mutex);
+}
+EXPORT_SYMBOL(drm_connector_cec_phys_addr_set);
 
 /**
  * drm_connector_cleanup - cleans up an initialised connector

include/drm/drm_connector.h

···
 			   bool enable, int direction);
 };
 
+void drm_connector_cec_phys_addr_invalidate(struct drm_connector *connector);
+void drm_connector_cec_phys_addr_set(struct drm_connector *connector);
+
+/**
+ * struct drm_connector_cec_funcs - drm_hdmi_connector control functions
+ */
+struct drm_connector_cec_funcs {
+	/**
+	 * @phys_addr_invalidate: mark CEC physical address as invalid
+	 *
+	 * The callback to mark CEC physical address as invalid, abstracting
+	 * the operation.
+	 */
+	void (*phys_addr_invalidate)(struct drm_connector *connector);
+
+	/**
+	 * @phys_addr_set: set CEC physical address
+	 *
+	 * The callback to set CEC physical address, abstracting the operation.
+	 */
+	void (*phys_addr_set)(struct drm_connector *connector, u16 addr);
+};
+
 /**
  * struct drm_connector_hdmi_funcs - drm_hdmi_connector control functions
  */
···
 };
 
 /**
+ * struct drm_connector_cec - DRM Connector CEC-related structure
+ */
+struct drm_connector_cec {
+	/**
+	 * @mutex: protects all fields in this structure.
+	 */
+	struct mutex mutex;
+
+	/**
+	 * @funcs: CEC Control Functions
+	 */
+	const struct drm_connector_cec_funcs *funcs;
+
+	/**
+	 * @data: CEC implementation-specific data
+	 */
+	void *data;
+};
+
+/**
  * struct drm_connector - central DRM connector control structure
  *
  * Each connector may be connected to one or more CRTCs, or may be clonable by
···
 	 * @hdmi_audio: HDMI codec properties and non-DRM state.
 	 */
 	struct drm_connector_hdmi_audio hdmi_audio;
+
+	/**
+	 * @cec: CEC-related data.
+	 */
+	struct drm_connector_cec cec;
 };
 
 #define obj_to_connector(x) container_of(x, struct drm_connector, base)