diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
index d2efc98090ce..d747c0905827 100644
--- a/drivers/usb/host/xhci-rcar.c
+++ b/drivers/usb/host/xhci-rcar.c
@@ -32,29 +32,6 @@
 MODULE_FIRMWARE(XHCI_RCAR_FIRMWARE_NAME_V1);
 MODULE_FIRMWARE(XHCI_RCAR_FIRMWARE_NAME_V3);
 
-static void xhci_rcar_start_gen2(struct usb_hcd *hcd)
-{
-	/* LCLK Select */
-	writel(RCAR_USB3_LCLK_ENA_VAL, hcd->regs + RCAR_USB3_LCLK);
-	/* USB3.0 Configuration */
-	writel(RCAR_USB3_CONF1_VAL, hcd->regs + RCAR_USB3_CONF1);
-	writel(RCAR_USB3_CONF2_VAL, hcd->regs + RCAR_USB3_CONF2);
-	writel(RCAR_USB3_CONF3_VAL, hcd->regs + RCAR_USB3_CONF3);
-	/* USB3.0 Polarity */
-	writel(RCAR_USB3_RX_POL_VAL, hcd->regs + RCAR_USB3_RX_POL);
-	writel(RCAR_USB3_TX_POL_VAL, hcd->regs + RCAR_USB3_TX_POL);
-}
-
-static int xhci_rcar_is_gen2(struct device *dev)
-{
-	struct device_node *node = dev->of_node;
-
-	return of_device_is_compatible(node, "renesas,xhci-r8a7790") ||
-		of_device_is_compatible(node, "renesas,xhci-r8a7791") ||
-		of_device_is_compatible(node, "renesas,xhci-r8a7793") ||
-		of_device_is_compatible(node, "renesas,rcar-gen2-xhci");
-}
-
 static void xhci_rcar_start(struct usb_hcd *hcd)
 {
 	u32 temp;
@@ -64,8 +41,23 @@ static void xhci_rcar_start(struct usb_hcd *hcd)
 		temp = readl(hcd->regs + RCAR_USB3_INT_ENA);
 		temp |= RCAR_USB3_INT_ENA_VAL;
 		writel(temp, hcd->regs + RCAR_USB3_INT_ENA);
-		if (xhci_rcar_is_gen2(hcd->self.controller))
-			xhci_rcar_start_gen2(hcd);
+	}
+}
+
+static void xhci_rcar_gen2_start(struct usb_hcd *hcd)
+{
+	if (hcd->regs != NULL) {
+		xhci_rcar_start(hcd);
+
+		/* LCLK Select */
+		writel(RCAR_USB3_LCLK_ENA_VAL, hcd->regs + RCAR_USB3_LCLK);
+		/* USB3.0 Configuration */
+		writel(RCAR_USB3_CONF1_VAL, hcd->regs + RCAR_USB3_CONF1);
+		writel(RCAR_USB3_CONF2_VAL, hcd->regs + RCAR_USB3_CONF2);
+		writel(RCAR_USB3_CONF3_VAL, hcd->regs + RCAR_USB3_CONF3);
+		/* USB3.0 Polarity */
+		writel(RCAR_USB3_RX_POL_VAL, hcd->regs + RCAR_USB3_RX_POL);
+		writel(RCAR_USB3_TX_POL_VAL, hcd->regs + RCAR_USB3_TX_POL);
 	}
 }
 
@@ -192,13 +184,16 @@ static int xhci_rcar_init_quirk(struct usb_hcd *hcd)
 
 static int xhci_rcar_resume_quirk(struct usb_hcd *hcd)
 {
+	struct xhci_plat_priv *priv;
 	int ret;
 
 	ret = xhci_rcar_download_firmware(hcd);
-	if (!ret)
-		xhci_rcar_start(hcd);
+	if (ret)
+		return ret;
 
-	return ret;
+	priv = hcd_to_xhci_priv(hcd);
+	priv->plat_start(hcd);
+	return 0;
 }
 
 /*
@@ -217,7 +212,7 @@ static const struct xhci_plat_priv xhci_plat_renesas_rcar_gen2 = {
 	.firmware_name = XHCI_RCAR_FIRMWARE_NAME_V1,
 	.quirks = XHCI_NO_64BIT_SUPPORT |  XHCI_SLOW_SUSPEND,
 	.init_quirk = xhci_rcar_init_quirk,
-	.plat_start = xhci_rcar_start,
+	.plat_start = xhci_rcar_gen2_start,
 	.resume_quirk = xhci_rcar_resume_quirk,
 };