usb: typec: qcom-pmic-typec: register drm_bridge

The current approach to handling DP on bridge-enabled platforms requires
a chain of DP bridges up to the USB-C connector. Register a last DRM
bridge for such chain.
Acked-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230817150824.14371-3-dmitry.baryshkov@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/Kconfig

@@ -79,6 +79,7 @@ config TYPEC_WCOVE
 config TYPEC_QCOM_PMIC
 	tristate "Qualcomm PMIC USB Type-C Port Controller Manager driver"
 	depends on ARCH_QCOM || COMPILE_TEST
+	depends on DRM || DRM=n
 	help
 	  A Type-C port and Power Delivery driver which aggregates two
 	  discrete pieces of silicon in the PM8150b PMIC block: the

drivers/usb/typec/tcpm/qcom/qcom_pmic_typec.c

@@ -17,6 +17,9 @@
 #include <linux/usb/role.h>
 #include <linux/usb/tcpm.h>
 #include <linux/usb/typec_mux.h>
+
+#include <drm/drm_bridge.h>
+
 #include "qcom_pmic_typec_pdphy.h"
 #include "qcom_pmic_typec_port.h"
 
@@ -33,6 +36,7 @@ struct pmic_typec {
 	struct pmic_typec_port	*pmic_typec_port;
 	bool			vbus_enabled;
 	struct mutex		lock;		/* VBUS state serialization */
+	struct drm_bridge	bridge;
 };
 
 #define tcpc_to_tcpm(_tcpc_) container_of(_tcpc_, struct pmic_typec, tcpc)
@@ -146,6 +150,35 @@ static int qcom_pmic_typec_init(struct tcpc_dev *tcpc)
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_DRM)
+static int qcom_pmic_typec_attach(struct drm_bridge *bridge,
+				     enum drm_bridge_attach_flags flags)
+{
+	return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
+}
+
+static const struct drm_bridge_funcs qcom_pmic_typec_bridge_funcs = {
+	.attach = qcom_pmic_typec_attach,
+};
+
+static int qcom_pmic_typec_init_drm(struct pmic_typec *tcpm)
+{
+	tcpm->bridge.funcs = &qcom_pmic_typec_bridge_funcs;
+#ifdef CONFIG_OF
+	tcpm->bridge.of_node = of_get_child_by_name(tcpm->dev->of_node, "connector");
+#endif
+	tcpm->bridge.ops = DRM_BRIDGE_OP_HPD;
+	tcpm->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
+
+	return devm_drm_bridge_add(tcpm->dev, &tcpm->bridge);
+}
+#else
+static int qcom_pmic_typec_init_drm(struct pmic_typec *tcpm)
+{
+	return 0;
+}
+#endif
+
 static int qcom_pmic_typec_probe(struct platform_device *pdev)
 {
 	struct pmic_typec *tcpm;
@@ -208,6 +241,10 @@ static int qcom_pmic_typec_probe(struct platform_device *pdev)
 	mutex_init(&tcpm->lock);
 	platform_set_drvdata(pdev, tcpm);
 
+	ret = qcom_pmic_typec_init_drm(tcpm);
+	if (ret)
+		return ret;
+
 	tcpm->tcpc.fwnode = device_get_named_child_node(tcpm->dev, "connector");
 	if (!tcpm->tcpc.fwnode)
 		return -EINVAL;