drm/display: bridge-connector: handle CEC adapters

Implement necessary glue code to let DRM bridge drivers to implement CEC
adapters support.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250517-drm-hdmi-connector-cec-v6-9-35651db6f19b@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

diff --git a/drivers/gpu/drm/display/Kconfig b/drivers/gpu/drm/display/Kconfig
index 6376ea01ec3093a72de25064e31223d2c9868ed7..df09cf9a8ca19ea894d6f2fad68c0b191e81e3d0 100644 (file)
--- a/drivers/gpu/drm/display/Kconfig
+++ b/drivers/gpu/drm/display/Kconfig
@@ -17,6 +17,7 @@ if DRM_DISPLAY_HELPER
 config DRM_BRIDGE_CONNECTOR
        bool
        select DRM_DISPLAY_HDMI_AUDIO_HELPER
+       select DRM_DISPLAY_HDMI_CEC_HELPER
        select DRM_DISPLAY_HDMI_STATE_HELPER
        help
          DRM connector implementation terminating DRM bridge chains.

diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 0377dcd691a871643710d667248b05f8eb9e84d6..58846e26f1e1b8ce82459ea2e82c605cdb7ab84a 100644 (file)
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -554,6 +554,65 @@ static const struct drm_connector_hdmi_audio_funcs drm_bridge_connector_hdmi_aud
        .mute_stream = drm_bridge_connector_audio_mute_stream,
 };
 
+static int drm_bridge_connector_hdmi_cec_enable(struct drm_connector *connector, bool enable)
+{
+       struct drm_bridge_connector *bridge_connector =
+               to_drm_bridge_connector(connector);
+       struct drm_bridge *bridge;
+
+       bridge = bridge_connector->bridge_hdmi_cec;
+
+       return bridge->funcs->hdmi_cec_enable(bridge, enable);
+}
+
+static int drm_bridge_connector_hdmi_cec_log_addr(struct drm_connector *connector, u8 logical_addr)
+{
+       struct drm_bridge_connector *bridge_connector =
+               to_drm_bridge_connector(connector);
+       struct drm_bridge *bridge;
+
+       bridge = bridge_connector->bridge_hdmi_cec;
+
+       return bridge->funcs->hdmi_cec_log_addr(bridge, logical_addr);
+}
+
+static int drm_bridge_connector_hdmi_cec_transmit(struct drm_connector *connector,
+                                                 u8 attempts,
+                                                 u32 signal_free_time,
+                                                 struct cec_msg *msg)
+{
+       struct drm_bridge_connector *bridge_connector =
+               to_drm_bridge_connector(connector);
+       struct drm_bridge *bridge;
+
+       bridge = bridge_connector->bridge_hdmi_cec;
+
+       return bridge->funcs->hdmi_cec_transmit(bridge, attempts,
+                                               signal_free_time,
+                                               msg);
+}
+
+static int drm_bridge_connector_hdmi_cec_init(struct drm_connector *connector)
+{
+       struct drm_bridge_connector *bridge_connector =
+               to_drm_bridge_connector(connector);
+       struct drm_bridge *bridge;
+
+       bridge = bridge_connector->bridge_hdmi_cec;
+
+       if (!bridge->funcs->hdmi_cec_init)
+               return 0;
+
+       return bridge->funcs->hdmi_cec_init(connector, bridge);
+}
+
+static const struct drm_connector_hdmi_cec_funcs drm_bridge_connector_hdmi_cec_funcs = {
+       .init = drm_bridge_connector_hdmi_cec_init,
+       .enable = drm_bridge_connector_hdmi_cec_enable,
+       .log_addr = drm_bridge_connector_hdmi_cec_log_addr,
+       .transmit = drm_bridge_connector_hdmi_cec_transmit,
+};
+
 /* -----------------------------------------------------------------------------
  * Bridge Connector Initialisation
  */
@@ -677,6 +736,18 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
                        bridge_connector->bridge_hdmi_cec = bridge;
                }
 
+               if (bridge->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) {
+                       if (bridge_connector->bridge_hdmi_cec)
+                               return ERR_PTR(-EBUSY);
+
+                       bridge_connector->bridge_hdmi_cec = bridge;
+
+                       if (!bridge->funcs->hdmi_cec_enable ||
+                           !bridge->funcs->hdmi_cec_log_addr ||
+                           !bridge->funcs->hdmi_cec_transmit)
+                               return ERR_PTR(-EINVAL);
+               }
+
                if (!drm_bridge_get_next_bridge(bridge))
                        connector_type = bridge->type;
 
@@ -748,6 +819,17 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
                        return ERR_PTR(ret);
        }
 
+       if (bridge_connector->bridge_hdmi_cec &&
+           bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) {
+               ret = drmm_connector_hdmi_cec_register(connector,
+                                                      &drm_bridge_connector_hdmi_cec_funcs,
+                                                      bridge->hdmi_cec_adapter_name,
+                                                      bridge->hdmi_cec_available_las,
+                                                      bridge->hdmi_cec_dev);
+               if (ret)
+                       return ERR_PTR(ret);
+       }
+
        drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
 
        if (bridge_connector->bridge_hpd)

diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 0e5f6a007d536215bd50e11846433290c2060b9c..cc9f7df38102e3c43913b35312f0ed5c4d8a7bd0 100644 (file)
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -32,6 +32,7 @@
 #include <drm/drm_mode_object.h>
 #include <drm/drm_modes.h>
 
+struct cec_msg;
 struct device_node;
 
 struct drm_bridge;
@@ -737,6 +738,16 @@ struct drm_bridge_funcs {
                                      struct drm_bridge *bridge,
                                      bool enable, int direction);
 
+       int (*hdmi_cec_init)(struct drm_connector *connector,
+                            struct drm_bridge *bridge);
+
+       int (*hdmi_cec_enable)(struct drm_bridge *bridge, bool enable);
+
+       int (*hdmi_cec_log_addr)(struct drm_bridge *bridge, u8 logical_addr);
+
+       int (*hdmi_cec_transmit)(struct drm_bridge *bridge, u8 attempts,
+                                u32 signal_free_time, struct cec_msg *msg);
+
        /**
         * @dp_audio_startup:
         *
@@ -912,6 +923,11 @@ enum drm_bridge_ops {
         * to be present.
         */
        DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER = BIT(7),
+       /**
+        * @DRM_BRIDGE_OP_HDMI_CEC_ADAPTER: The bridge requires CEC notifier
+        * to be present.
+        */
+       DRM_BRIDGE_OP_HDMI_CEC_ADAPTER = BIT(8),
 };
 
 /**
@@ -1048,6 +1064,16 @@ struct drm_bridge {
         */
        int hdmi_audio_dai_port;
 
+       /**
+        * @hdmi_cec_adapter_name: the name of the adapter to register
+        */
+       const char *hdmi_cec_adapter_name;
+
+       /**
+        * @hdmi_cec_available_las: number of logical addresses, CEC_MAX_LOG_ADDRS if unset
+        */
+       u8 hdmi_cec_available_las;
+
        /** private: */
        /**
         * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.