The binding of iMX8MQ USB controller doesn't use child nodes like the
other devices supported in this driver. To support it split the child
nodes parsing to its own function and add a field to the platform data
to indicate that we should just use the top node.

Signed-off-by: Alban Bedel <alban.bedel@aerq.com>
---
 drivers/usb/dwc3/dwc3-generic.c | 95 +++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 39 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 01bd0ca190e3..defef43ff503 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -221,6 +221,7 @@ U_BOOT_DRIVER(dwc3_generic_host) = {
 struct dwc3_glue_ops {
 	void (*select_dr_mode)(struct udevice *dev, int index,
 			       enum usb_dr_mode mode);
+	int single_node;
 };
 
 void dwc3_ti_select_dr_mode(struct udevice *dev, int index,
@@ -307,54 +308,66 @@ struct dwc3_glue_ops ti_ops = {
 	.select_dr_mode = dwc3_ti_select_dr_mode,
 };
 
+static int dwc3_glue_bind_node(struct udevice *parent, ofnode node,
+			       enum usb_dr_mode dr_mode)
+{
+	const char *name = ofnode_get_name(node);
+	const char *driver = NULL;
+	struct udevice *dev;
+	int ret;
+
+	debug("%s: subnode name: %s\n", __func__, name);
+
+	/* if the parent node doesn't have a mode check the leaf */
+	if (!dr_mode)
+		dr_mode = usb_get_dr_mode(node);
+
+	switch (dr_mode) {
+	case USB_DR_MODE_PERIPHERAL:
+	case USB_DR_MODE_OTG:
+#if CONFIG_IS_ENABLED(DM_USB_GADGET)
+		debug("%s: dr_mode: OTG or Peripheral\n", __func__);
+		driver = "dwc3-generic-peripheral";
+#endif
+		break;
+#if defined(CONFIG_SPL_USB_HOST) || !defined(CONFIG_SPL_BUILD)
+	case USB_DR_MODE_HOST:
+		debug("%s: dr_mode: HOST\n", __func__);
+		driver = "dwc3-generic-host";
+		break;
+#endif
+	default:
+		debug("%s: unsupported dr_mode\n", __func__);
+		return -ENODEV;
+	};
+
+	if (!driver)
+		return 0;
+
+	ret = device_bind_driver_to_node(parent, driver, name,
+					 node, &dev);
+	if (ret)
+		debug("%s: not able to bind usb device mode\n",
+		      __func__);
+	return ret;
+}
+
 static int dwc3_glue_bind(struct udevice *parent)
 {
+	struct dwc3_glue_ops *ops = (struct dwc3_glue_ops *)dev_get_driver_data(parent);
 	ofnode node;
 	int ret;
 	enum usb_dr_mode dr_mode;
 
+	if (ops->single_node)
+		return dwc3_glue_bind_node(parent, dev_ofnode(parent), 0);
+
 	dr_mode = usb_get_dr_mode(dev_ofnode(parent));
 
 	ofnode_for_each_subnode(node, dev_ofnode(parent)) {
-		const char *name = ofnode_get_name(node);
-		struct udevice *dev;
-		const char *driver = NULL;
-
-		debug("%s: subnode name: %s\n", __func__, name);
-
-		/* if the parent node doesn't have a mode check the leaf */
-		if (!dr_mode)
-			dr_mode = usb_get_dr_mode(node);
-
-		switch (dr_mode) {
-		case USB_DR_MODE_PERIPHERAL:
-		case USB_DR_MODE_OTG:
-#if CONFIG_IS_ENABLED(DM_USB_GADGET)
-			debug("%s: dr_mode: OTG or Peripheral\n", __func__);
-			driver = "dwc3-generic-peripheral";
-#endif
-			break;
-#if defined(CONFIG_SPL_USB_HOST) || !defined(CONFIG_SPL_BUILD)
-		case USB_DR_MODE_HOST:
-			debug("%s: dr_mode: HOST\n", __func__);
-			driver = "dwc3-generic-host";
-			break;
-#endif
-		default:
-			debug("%s: unsupported dr_mode\n", __func__);
-			return -ENODEV;
-		};
-
-		if (!driver)
-			continue;
-
-		ret = device_bind_driver_to_node(parent, driver, name,
-						 node, &dev);
-		if (ret) {
-			debug("%s: not able to bind usb device mode\n",
-			      __func__);
+		ret = dwc3_glue_bind_node(parent, node, dr_mode);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -454,6 +467,10 @@ static int dwc3_glue_remove(struct udevice *dev)
 	return 0;
 }
 
+struct dwc3_glue_ops single_node_ops = {
+	.single_node = 1,
+};
+
 static const struct udevice_id dwc3_glue_ids[] = {
 	{ .compatible = "xlnx,zynqmp-dwc3" },
 	{ .compatible = "xlnx,versal-dwc3" },
@@ -464,7 +481,7 @@ static const struct udevice_id dwc3_glue_ids[] = {
 	{ .compatible = "rockchip,rk3328-dwc3" },
 	{ .compatible = "rockchip,rk3399-dwc3" },
 	{ .compatible = "qcom,dwc3" },
-	{ .compatible = "fsl,imx8mq-dwc3" },
+	{ .compatible = "fsl,imx8mq-dwc3", .data = (ulong)&single_node_ops },
 	{ .compatible = "intel,tangier-dwc3" },
 	{ }
 };
-- 
2.32.0