@@ -94,6 +94,9 @@ static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
 	int ret;
 	int i;
 
+	if (ippc == NULL)
+		return 0;
+
 	/* power on host ip */
 	value = readl(&ippc->ip_pw_ctr1);
 	value &= ~CTRL1_IP_HOST_PDN;

@@ -139,6 +142,9 @@ static int xhci_mtk_host_disable(struct xhci_hcd_mtk *mtk)
 	int ret;
 	int i;
 
+	if (ippc == NULL)
+		return 0;
+
 	/* power down all u3 ports */
 	for (i = 0; i < mtk->num_u3_ports; i++) {
 		value = readl(&ippc->u3_ctrl_p[i]);

@@ -173,6 +179,9 @@ static int xhci_mtk_ssusb_config(struct xhci_hcd_mtk *mtk)
 	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
 	u32 value;
 
+	if (ippc == NULL)
+		return 0;
+
 	/* reset whole ip */
 	value = readl(&ippc->ip_pw_ctr0);
 	value |= CTRL0_IP_SW_RST;

@@ -475,6 +484,7 @@ static void xhci_mtk_quirks(struct device *dev, struct xhci_hcd *xhci)
 /* called during probe() after chip reset completes */
 static int xhci_mtk_setup(struct usb_hcd *hcd)
 {
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
 	int ret;
 

@@ -482,12 +492,21 @@ static int xhci_mtk_setup(struct usb_hcd *hcd)
 		ret = xhci_mtk_ssusb_config(mtk);
 		if (ret)
 			return ret;
+	}
+
+	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
+	if (ret)
+		return ret;
+
+	if (usb_hcd_is_primary_hcd(hcd)) {
+		mtk->num_u3_ports = xhci->num_usb3_ports;
+		mtk->num_u2_ports = xhci->num_usb2_ports;
 		ret = xhci_mtk_sch_init(mtk);
 		if (ret)
 			return ret;
 	}
 
-	return xhci_gen_setup(hcd, xhci_mtk_quirks);
+	return ret;
 }
 
 static int xhci_mtk_probe(struct platform_device *pdev)

@@ -595,11 +614,14 @@ static int xhci_mtk_probe(struct platform_device *pdev)
 	hcd->rsrc_start = res->start;
 	hcd->rsrc_len = resource_size(res);
 
+	mtk->ippc_regs = NULL;
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	mtk->ippc_regs = devm_ioremap_resource(dev, res);
-	if (IS_ERR(mtk->ippc_regs)) {
-		ret = PTR_ERR(mtk->ippc_regs);
-		goto put_usb2_hcd;
+	if (res) {	/* ippc register is optional */
+		mtk->ippc_regs = devm_ioremap_resource(dev, res);
+		if (IS_ERR(mtk->ippc_regs)) {
+			ret = PTR_ERR(mtk->ippc_regs);
+			goto put_usb2_hcd;
+		}
 	}
 
 	for (phy_num = 0; phy_num < mtk->num_phys; phy_num++) {