usb: typec: Add typec_get_driver_from_usb() API

The typec_get_driver_from_usb() allows to retrieve a Type-C device from
an USB device.
typec_get_driver_from_usb() checks in USB device node for port and endpoint
sub-node, if exist, retrieve the connector node, probe the associated
Type-C device and return it.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Change-Id: If564cdf463f3915bec26f17a4717c9ab9d42f692
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/u-boot/+/232353
Reviewed-by: CITOOLS <MDG-smet-aci-reviews@list.st.com>
Reviewed-by: Patrick DELAUNAY <patrick.delaunay@foss.st.com>

drivers/usb/typec/typec-uclass.c

@@ -10,6 +10,74 @@
 #include <errno.h>
 #include <typec.h>
 #include <dm/device_compat.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+
+int typec_get_device_from_usb(struct udevice *dev, struct udevice **typec, u8 index)
+{
+	ofnode node, child;
+	u32 endpoint_phandle;
+	u32 reg;
+	int ret;
+
+	/* 'port' nodes can be grouped under an optional 'ports' node */
+	node = dev_read_subnode(dev, "ports");
+	if (!ofnode_valid(node)) {
+		node = dev_read_subnode(dev, "port");
+	} else {
+		/* several 'port' nodes, found the requested port@index one */
+		ofnode_for_each_subnode(child, node) {
+			ofnode_read_u32(child, "reg", &reg);
+			if (index == reg) {
+				node = child;
+				break;
+			}
+		}
+		node = child;
+	}
+
+	if (!ofnode_valid(node)) {
+		dev_dbg(dev, "connector port or port@%d subnode not found\n", index);
+		return -ENODEV;
+	}
+
+	/* get endpoint node */
+	node = ofnode_first_subnode(node);
+	if (!ofnode_valid(node))
+		return -EINVAL;
+
+	ret = ofnode_read_u32(node, "remote-endpoint", &endpoint_phandle);
+	if (ret)
+		return ret;
+
+	/* retrieve connector endpoint phandle */
+	node = ofnode_get_by_phandle(endpoint_phandle);
+	if (!ofnode_valid(node))
+		return -EINVAL;
+	/*
+	 * Use a while to retrieve an USB Type-C device either at connector
+	 * level or just above (depending if UCSI uclass is used or not)
+	 */
+	while (ofnode_valid(node)) {
+		node = ofnode_get_parent(node);
+		if (!ofnode_valid(node)) {
+			dev_err(dev, "No UCLASS_USB_TYPEC for remote-endpoint\n");
+			return -EINVAL;
+		}
+
+		uclass_find_device_by_ofnode(UCLASS_USB_TYPEC, node, typec);
+		if (*typec)
+			break;
+	}
+
+	ret = device_probe(*typec);
+	if (ret) {
+		dev_err(dev, "Type-C won't probe (ret=%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
 
 int typec_get_data_role(struct udevice *dev, u8 con_idx)
 {

include/typec.h

@@ -70,6 +70,66 @@ int typec_get_data_role(struct udevice *dev, u8 con_idx);
  * @return Type-C connector number or -ve on error.
  */
 int typec_get_nb_connector(struct udevice *dev);
+
+/**
+ * typec_get_device_from_usb() - Allows to retrieve a Type-C device from
+ * an USB device. typec_get_driver_from_usb() checks in USB device node
+ * for port and endpoint sub-node, if exist, retrieve the connector node,
+ * probe the associated Type-C device and return it (see DT example below).
+ * See Documentation/devicetree/bindings/connector/usb-connector.yaml for more
+ * details
+ *
+ * @dev: USB device
+ * @typec: Type-C device
+ * @index: USB controller port number
+ * @return -ve on error.
+ *
+ * usb_dwc3_0: usb@10000000 {
+ *	...
+ *	port@0 {
+ *		reg = <0>;
+ *		typec_hs: endpoint {
+ *			remote-endpoint = <&usb_con_hs>;
+ *		};
+ *	};
+ *
+ *	port@1 {
+ *		reg = <1>;
+ *		typec_ss: endpoint {
+ *			remote-endpoint = <&usb_con_ss>;
+ *		};
+ *	};
+ * };
+ *
+ * usb-typec@1 {
+ *	...
+ *	connector {
+ *		compatible = "usb-c-connector";
+ *		label = "USB-C";
+ *
+ *		ports {
+ *			#address-cells = <1>;
+ *			#size-cells = <0>;
+ *
+ *			port@0 {
+ *				reg = <0>;
+ *				usb_con_hs: endpoint {
+ *					remote-endpoint = <&typec_hs>;
+ *				};
+ *			};
+ *
+ *			port@1 {
+ *				reg = <1>;
+ *				usb_con_ss: endpoint {
+ *					remote-endpoint = <&typec_ss>;
+ *				};
+ *			};
+ *		};
+ *	};
+ * };
+ */
+int typec_get_device_from_usb(struct udevice *dev, struct udevice **typec, u8
+			      index);
 #else
 static inline int typec_is_attached(struct udevice *dev, u8 con_idx)
 {
@@ -85,5 +145,10 @@ static inline int typec_get_nb_connector(struct udevice *dev)
 {
 	return -EINVAL;
 }
-#endif
 
+static inline int typec_get_device_from_usb(struct udevice *dev, struct udevice **typec,
+					    u8 index)
+{
+	return -ENODEV;
+}
+#endif