[PATCH v7 06/10] drm/display/hdmi: implement hotplug functions

Dmitry Baryshkov
2024-12-17T00:48:22Z

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 drivers utilizing HDMI Connector
framework.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/gpu/drm/display/drm_hdmi_state_helper.c | 56 +++++++++++++++++++++++++
include/drm/display/drm_hdmi_state_helper.h | 5 +++
include/drm/drm_connector.h | 16 +++++++
3 files changed, 77 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index 80bf2829ba89b5f84fed4fa9eb1d6302e10a4f9e..e175c0eaa1cdc0b8b8b8408bdc3fdcf49067c634 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -769,3 +769,59 @@ drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector *con
return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_clear_audio_infoframe);
+
+static void
+drm_atomic_helper_connector_hdmi_update(struct drm_connector *connector,
+ enum drm_connector_status status)
+{
+ const struct drm_edid *drm_edid;
+
+ if (status == connector_status_disconnected) {
+ // TODO: also handle CEC and scramber, HDMI sink disconnected.
+ drm_connector_hdmi_codec_plugged_notify(connector, false);
+ }
+
+ if (connector->hdmi.funcs->read_edid)
+ drm_edid = connector->hdmi.funcs->read_edid(connector);
+ else
+ drm_edid = drm_edid_read(connector);
+
+ drm_edid_connector_update(connector, drm_edid);
+
+ drm_edid_free(drm_edid);
+
+ if (status == connector_status_connected) {
+ // TODO: also handle CEC and scramber, HDMI sink is now connected.
+ drm_connector_hdmi_codec_plugged_notify(connector, true);
+ }
+}
+
+/**
+ * drm_atomic_helper_connector_hdmi_hotplug - Handle the hotplug event for the HDMI connector
+ * @connector: A pointer to the HDMI connector
+ * @status: Connection status
+ *
+ * This function should be called as a part of the .detect() / .detect_ctx()
+ * callbacks, updating the HDMI-specific connector's data.
+ */
+void drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
+ enum drm_connector_status status)
+{
+ drm_atomic_helper_connector_hdmi_update(connector, status);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_hotplug);
+
+/**
+ * drm_atomic_helper_connector_hdmi_force - HDMI Connector implementation of the force callback
+ * @connector: A pointer to the HDMI connector
+ *
+ * This function implements the .force() callback for the HDMI connectors. It
+ * can either be used directly as the callback or should be called from within
+ * the .force() callback implementation to maintain the HDMI-specific
+ * connector's data.
+ */
+void drm_atomic_helper_connector_hdmi_force(struct drm_connector *connector)
+{
+ drm_atomic_helper_connector_hdmi_update(connector, connector->status);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_force);
diff --git a/include/drm/display/drm_hdmi_state_helper.h b/include/drm/display/drm_hdmi_state_helper.h
index d6d65da6d8f9ee46de33114cce2d6fbe6098a862..9ae19f3caf727f9a0fe06e6afe5fc46db924444f 100644
--- a/include/drm/display/drm_hdmi_state_helper.h
+++ b/include/drm/display/drm_hdmi_state_helper.h
@@ -8,6 +8,8 @@ struct drm_connector;
struct drm_connector_state;
struct hdmi_audio_infoframe;

+enum drm_connector_status;
+
void __drm_atomic_helper_connector_hdmi_reset(struct drm_connector *connector,
struct drm_connector_state *new_conn_state);

@@ -19,6 +21,9 @@ int drm_atomic_helper_connector_hdmi_update_audio_infoframe(struct drm_connector
int drm_atomic_helper_connector_hdmi_clear_audio_infoframe(struct drm_connector *connector);
int drm_atomic_helper_connector_hdmi_update_infoframes(struct drm_connector *connector,
struct drm_atomic_state *state);
+void drm_atomic_helper_connector_hdmi_hotplug(struct drm_connector *connector,
+ enum drm_connector_status status);
+void drm_atomic_helper_connector_hdmi_force(struct drm_connector *connector);

enum drm_mode_status
drm_hdmi_connector_mode_valid(struct drm_connector *connector,
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 536d604b6fb27368c43805a2ecf57fac06b3d472..23340696bf36313952da0089b9dc24dcf772a9c5 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -45,6 +45,7 @@ struct drm_property;
struct drm_property_blob;
struct drm_printer;
struct drm_privacy_screen;
+struct drm_edid;
struct edid;
struct hdmi_codec_daifmt;
struct hdmi_codec_params;
@@ -1247,6 +1248,21 @@ struct drm_connector_hdmi_funcs {
int (*write_infoframe)(struct drm_connector *connector,
enum hdmi_infoframe_type type,
const u8 *buffer, size_t len);
+
+ /**
+ * @read_edid:
+ *
+ * This callback is used by the framework as a replacement for reading
+ * the EDID from connector->ddc. It is still recommended to provide
+ * connector->ddc instead of implementing this callback. Returned EDID
+ * should be freed via the drm_edid_free().
+ *
+ * The @read_edid callback is optional.
+ *
+ * Returns:
+ * Valid EDID on success, NULL in case of failure.
+ */
+ const struct drm_edid *(*read_edid)(struct drm_connector *connector);
};

/**

--
2.39.5