The HDMI Connectors need to perform a variety of tasks when the HDMI
connector state changes. Such tasks include setting or invalidating CEC
address, notifying HDMI codec driver, updating scrambler data, etc.

Implementing such tasks in a driver-specific callbacks is error prone.
Start implementing the generic helper function (currently handling only
the HDMI Codec framework) to be used by driver utilizing HDMI Connector
framework.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 59 +++++++++++++++++++++++++
 include/drm/display/drm_hdmi_state_helper.h     |  5 +++
 2 files changed, 64 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index feb7a3a759811aed70c679be8704072093e2a79b..2230b7fc92cfee46a9cad2479edce71822d30934 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -748,3 +748,62 @@ drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector *con
 	return ret;
 }
 EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_clear_audio_infoframe);
+
+/**
+ * drm_atomic_helper_connector_hdmi_update_edid - Update the HDMI Connector basing on passed EDID
+ * @connector: A pointer to the HDMI connector
+ * @drm_edid: EDID to process
+ *
+ * This function should be called as a part of the .detect() / .detect_ctx()
+ * and .force() callbacks, updating the HDMI-specific connector's data. Most of
+ * the drivers should be able to use @drm_atomic_helper_connector_hdmi_update()
+ * instead.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int
+drm_atomic_helper_connector_hdmi_update_edid(struct drm_connector *connector,
+					     const struct drm_edid *drm_edid)
+{
+	drm_edid_connector_update(connector, drm_edid);
+
+	if (!drm_edid) {
+		drm_connector_hdmi_codec_plugged_notify(connector, false);
+
+		// TODO: also handle CEC and scramber, HDMI sink disconnected.
+
+		return 0;
+	}
+
+	drm_connector_hdmi_codec_plugged_notify(connector, true);
+
+	// TODO: also handle CEC and scramber, HDMI sink is now connected.
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_update_edid);
+
+/**
+ * drm_atomic_helper_connector_hdmi_update - Update the HDMI Connector after reading the EDID
+ * @connector: A pointer to the HDMI connector
+ *
+ * This function should be called as a part of the .detect() / .detect_ctx()
+ * and .force() callbacks, updating the HDMI-specific connector's data.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int
+drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector)
+{
+	const struct drm_edid *drm_edid;
+	int ret;
+
+	drm_edid = drm_edid_read(connector);
+	ret = drm_atomic_helper_connector_hdmi_update_edid(connector, drm_edid);
+	drm_edid_free(drm_edid);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_update);
diff --git a/include/drm/display/drm_hdmi_state_helper.h b/include/drm/display/drm_hdmi_state_helper.h
index 2d45fcfa461985065a5e5ad67eddc0b1c556d526..61c43e744051886ba5f2024197fcc90688670ebe 100644
--- a/include/drm/display/drm_hdmi_state_helper.h
+++ b/include/drm/display/drm_hdmi_state_helper.h
@@ -6,6 +6,7 @@
 struct drm_atomic_state;
 struct drm_connector;
 struct drm_connector_state;
+struct drm_edid;
 struct hdmi_audio_infoframe;
 
 void __drm_atomic_helper_connector_hdmi_reset(struct drm_connector *connector,
@@ -20,4 +21,8 @@ int drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector
 int drm_atomic_helper_connector_hdmi_update_infoframes(struct drm_connector *connector,
 						       struct drm_atomic_state *state);
 
+int drm_atomic_helper_connector_hdmi_update_edid(struct drm_connector *connector,
+						 const struct drm_edid *drm_edid);
+int drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector);
+
 #endif // DRM_HDMI_STATE_HELPER_H_

-- 
2.39.5