drm/vc4: hdmi: switch to generic CEC helpers

Switch VC4 driver to using CEC helpers code, simplifying hotplug and
registration / cleanup. The existing vc4_hdmi_cec_release() is kept for
now.

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

drivers/gpu/drm/vc4/Kconfig

···
 	bool "Broadcom VC4 HDMI CEC Support"
 	depends on DRM_VC4
 	select CEC_CORE
+	select DRM_DISPLAY_HDMI_CEC_HELPER
 	help
 	  Choose this option if you have a Broadcom VC4 GPU
 	  and want to use CEC.

drivers/gpu/drm/vc4/vc4_hdmi.c

···
  */
 
 #include <drm/display/drm_hdmi_audio_helper.h>
+#include <drm/display/drm_hdmi_cec_helper.h>
 #include <drm/display/drm_hdmi_helper.h>
 #include <drm/display/drm_hdmi_state_helper.h>
 #include <drm/display/drm_scdc_helper.h>
···
 	 */
 
 	drm_atomic_helper_connector_hdmi_hotplug(connector, status);
-
-	if (status == connector_status_disconnected) {
-		cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
-		return;
-	}
-
-	cec_s_phys_addr(vc4_hdmi->cec_adap,
-			connector->display_info.source_physical_address, false);
 
 	if (status != connector_status_connected)
 		return;
···
 	struct vc4_hdmi *vc4_hdmi = priv;
 
 	if (vc4_hdmi->cec_rx_msg.len)
-		cec_received_msg(vc4_hdmi->cec_adap,
-				 &vc4_hdmi->cec_rx_msg);
+		drm_connector_hdmi_cec_received_msg(&vc4_hdmi->connector,
+						    &vc4_hdmi->cec_rx_msg);
 
 	return IRQ_HANDLED;
 }
···
 	struct vc4_hdmi *vc4_hdmi = priv;
 
 	if (vc4_hdmi->cec_tx_ok) {
-		cec_transmit_done(vc4_hdmi->cec_adap, CEC_TX_STATUS_OK,
-				  0, 0, 0, 0);
+		drm_connector_hdmi_cec_transmit_done(&vc4_hdmi->connector,
+						     CEC_TX_STATUS_OK,
+						     0, 0, 0, 0);
 	} else {
 		/*
 		 * This CEC implementation makes 1 retry, so if we
 		 * get a NACK, then that means it made 2 attempts.
 		 */
-		cec_transmit_done(vc4_hdmi->cec_adap, CEC_TX_STATUS_NACK,
-				  0, 2, 0, 0);
+		drm_connector_hdmi_cec_transmit_done(&vc4_hdmi->connector,
+						     CEC_TX_STATUS_NACK,
+						     0, 2, 0, 0);
 	}
 	return IRQ_HANDLED;
 }
···
 	return ret;
 }
 
-static int vc4_hdmi_cec_enable(struct cec_adapter *adap)
+static int vc4_hdmi_cec_enable(struct drm_connector *connector)
 {
-	struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
+	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	/* clock period in microseconds */
 	const u32 usecs = 1000000 / CEC_CLOCK_FREQ;
···
 	return 0;
 }
 
-static int vc4_hdmi_cec_disable(struct cec_adapter *adap)
+static int vc4_hdmi_cec_disable(struct drm_connector *connector)
 {
-	struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
+	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	unsigned long flags;
 	int idx;
···
 	return 0;
 }
 
-static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
+static int vc4_hdmi_cec_adap_enable(struct drm_connector *connector, bool enable)
 {
 	if (enable)
-		return vc4_hdmi_cec_enable(adap);
+		return vc4_hdmi_cec_enable(connector);
 	else
-		return vc4_hdmi_cec_disable(adap);
+		return vc4_hdmi_cec_disable(connector);
 }
 
-static int vc4_hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
+static int vc4_hdmi_cec_adap_log_addr(struct drm_connector *connector, u8 log_addr)
 {
-	struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
+	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
 	struct drm_device *drm = vc4_hdmi->connector.dev;
 	unsigned long flags;
 	int idx;
···
 	return 0;
 }
 
-static int vc4_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+static int vc4_hdmi_cec_adap_transmit(struct drm_connector *connector, u8 attempts,
 				      u32 signal_free_time, struct cec_msg *msg)
 {
-	struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
+	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
 	struct drm_device *dev = vc4_hdmi->connector.dev;
 	unsigned long flags;
 	u32 val;
···
 	return 0;
 }
 
-static const struct cec_adap_ops vc4_hdmi_cec_adap_ops = {
-	.adap_enable = vc4_hdmi_cec_adap_enable,
-	.adap_log_addr = vc4_hdmi_cec_adap_log_addr,
-	.adap_transmit = vc4_hdmi_cec_adap_transmit,
-};
-
-static void vc4_hdmi_cec_release(void *ptr)
+static int vc4_hdmi_cec_init(struct drm_connector *connector)
 {
-	struct vc4_hdmi *vc4_hdmi = ptr;
-
-	cec_unregister_adapter(vc4_hdmi->cec_adap);
-	vc4_hdmi->cec_adap = NULL;
-}
-
-static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
-{
-	struct cec_connector_info conn_info;
+	struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
 	struct platform_device *pdev = vc4_hdmi->pdev;
 	struct device *dev = &pdev->dev;
 	int ret;
-
-	if (!of_property_present(dev->of_node, "interrupts")) {
-		dev_warn(dev, "'interrupts' DT property is missing, no CEC\n");
-		return 0;
-	}
-
-	vc4_hdmi->cec_adap = cec_allocate_adapter(&vc4_hdmi_cec_adap_ops,
-						  vc4_hdmi,
-						  vc4_hdmi->variant->card_name,
-						  CEC_CAP_DEFAULTS |
-						  CEC_CAP_CONNECTOR_INFO, 1);
-	ret = PTR_ERR_OR_ZERO(vc4_hdmi->cec_adap);
-	if (ret < 0)
-		return ret;
-
-	cec_fill_conn_info_from_drm(&conn_info, &vc4_hdmi->connector);
-	cec_s_conn_info(vc4_hdmi->cec_adap, &conn_info);
 
 	if (vc4_hdmi->variant->external_irq_controller) {
 		ret = devm_request_threaded_irq(dev, platform_get_irq_byname(pdev, "cec-rx"),
···
 						vc4_cec_irq_handler_rx_thread, 0,
 						"vc4 hdmi cec rx", vc4_hdmi);
 		if (ret)
-			goto err_delete_cec_adap;
+			return ret;
 
 		ret = devm_request_threaded_irq(dev, platform_get_irq_byname(pdev, "cec-tx"),
 						vc4_cec_irq_handler_tx_bare,
 						vc4_cec_irq_handler_tx_thread, 0,
 						"vc4 hdmi cec tx", vc4_hdmi);
 		if (ret)
-			goto err_delete_cec_adap;
+			return ret;
 	} else {
 		ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
 						vc4_cec_irq_handler,
 						vc4_cec_irq_handler_thread, 0,
 						"vc4 hdmi cec", vc4_hdmi);
 		if (ret)
-			goto err_delete_cec_adap;
+			return ret;
 	}
 
-	ret = cec_register_adapter(vc4_hdmi->cec_adap, &pdev->dev);
-	if (ret < 0)
-		goto err_delete_cec_adap;
+	return 0;
+}
+
+static const struct drm_connector_hdmi_cec_funcs vc4_hdmi_cec_funcs = {
+	.init = vc4_hdmi_cec_init,
+	.enable = vc4_hdmi_cec_adap_enable,
+	.log_addr = vc4_hdmi_cec_adap_log_addr,
+	.transmit = vc4_hdmi_cec_adap_transmit,
+};
+
+static int vc4_hdmi_cec_register(struct vc4_hdmi *vc4_hdmi)
+{
+	struct platform_device *pdev = vc4_hdmi->pdev;
+	struct device *dev = &pdev->dev;
+
+	if (!of_property_present(dev->of_node, "interrupts")) {
+		dev_warn(dev, "'interrupts' DT property is missing, no CEC\n");
+		return 0;
+	}
 
 	/*
-	 * NOTE: Strictly speaking, we should probably use a DRM-managed
-	 * registration there to avoid removing the CEC adapter by the
-	 * time the DRM driver doesn't have any user anymore.
+	 * NOTE: the CEC adapter will be unregistered by drmm cleanup from
+	 * drm_managed_release(), which is called from drm_dev_release()
+	 * during device unbind.
 	 *
 	 * However, the CEC framework already cleans up the CEC adapter
 	 * only when the last user has closed its file descriptor, so we
 	 * don't need to handle it in DRM.
-	 *
-	 * By the time the device-managed hook is executed, we will give
-	 * up our reference to the CEC adapter and therefore don't
-	 * really care when it's actually freed.
 	 *
 	 * There's still a problematic sequence: if we unregister our
 	 * CEC adapter, but the userspace keeps a handle on the CEC
···
 	 * the CEC framework already handles this too, by calling
 	 * cec_is_registered() in cec_ioctl() and cec_poll().
 	 */
-	ret = devm_add_action_or_reset(dev, vc4_hdmi_cec_release, vc4_hdmi);
-	if (ret)
-		return ret;
-
-	return 0;
-
-err_delete_cec_adap:
-	cec_delete_adapter(vc4_hdmi->cec_adap);
-
-	return ret;
+	return drmm_connector_hdmi_cec_register(&vc4_hdmi->connector,
+						&vc4_hdmi_cec_funcs,
+						vc4_hdmi->variant->card_name,
+						1,
+						&pdev->dev);
 }
 #else
-static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
+static int vc4_hdmi_cec_register(struct vc4_hdmi *vc4_hdmi)
 {
 	return 0;
 }
···
 	if (ret)
 		goto err_put_runtime_pm;
 
-	ret = vc4_hdmi_cec_init(vc4_hdmi);
+	ret = vc4_hdmi_cec_register(vc4_hdmi);
 	if (ret)
 		goto err_put_runtime_pm;
 

drivers/gpu/drm/vc4/vc4_hdmi.h

···
 	 */
 	bool disable_wifi_frequencies;
 
-	struct cec_adapter *cec_adap;
 	struct cec_msg cec_rx_msg;
 	bool cec_tx_ok;
 	bool cec_irq_was_rx;