usb: renesas_usbhs: add support for generic PHY

This patch adds support for the generic PHY. The generic PHY will be
used in multiplatform environment.

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/renesas_usbhs/common.h

@@ -270,6 +270,7 @@ struct usbhs_priv {
 	struct usbhs_fifo_info fifo_info;
 
 	struct usb_phy *usb_phy;
+	struct phy *phy;
 };
 
 /*

drivers/usb/renesas_usbhs/rcar2.c

@@ -12,6 +12,7 @@
 
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
+#include <linux/phy/phy.h>
 #include <linux/platform_data/gpio-rcar.h>
 #include <linux/usb/phy.h>
 #include "common.h"
@@ -21,6 +22,16 @@ static int usbhs_rcar2_hardware_init(struct platform_device *pdev)
 {
 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
 
+	if (IS_ENABLED(CONFIG_GENERIC_PHY)) {
+		struct phy *phy = phy_get(&pdev->dev, "usb");
+
+		if (IS_ERR(phy))
+			return PTR_ERR(phy);
+
+		priv->phy = phy;
+		return 0;
+	}
+
 	if (IS_ENABLED(CONFIG_USB_PHY)) {
 		struct usb_phy *usb_phy = usb_get_phy_dev(&pdev->dev, 0);
 
@@ -38,6 +49,11 @@ static int usbhs_rcar2_hardware_exit(struct platform_device *pdev)
 {
 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
 
+	if (priv->phy) {
+		phy_put(priv->phy);
+		priv->phy = NULL;
+	}
+
 	if (priv->usb_phy) {
 		usb_put_phy(priv->usb_phy);
 		priv->usb_phy = NULL;
@@ -52,6 +68,19 @@ static int usbhs_rcar2_power_ctrl(struct platform_device *pdev,
 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
 	int retval = -ENODEV;
 
+	if (priv->phy) {
+		if (enable) {
+			retval = phy_init(priv->phy);
+
+			if (!retval)
+				retval = phy_power_on(priv->phy);
+		} else {
+			phy_power_off(priv->phy);
+			phy_exit(priv->phy);
+			retval = 0;
+		}
+	}
+
 	if (priv->usb_phy) {
 		if (enable) {
 			retval = usb_phy_init(priv->usb_phy);