usb: renesas_usbhs: Allow an OTG PHY driver to provide VBUS

These changes allow a PHY driver to trigger a VBUS interrupt and
to provide the value of VBUS.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/renesas_usbhs/mod_gadget.c

@@ -21,6 +21,7 @@
 #include <linux/platform_device.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
 #include "common.h"
 
 /*
@@ -50,6 +51,8 @@ struct usbhsg_gpriv {
 	int			 uep_size;
 
 	struct usb_gadget_driver	*driver;
+	struct usb_phy		*transceiver;
+	bool			 vbus_active;
 
 	u32	status;
 #define USBHSG_STATUS_STARTED		(1 << 0)
@@ -872,6 +875,27 @@ static int usbhsg_try_stop(struct usbhs_priv *priv, u32 status)
 	return 0;
 }
 
+/*
+ * VBUS provided by the PHY
+ */
+static int usbhsm_phy_get_vbus(struct platform_device *pdev)
+{
+	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
+	struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
+
+	return  gpriv->vbus_active;
+}
+
+static void usbhs_mod_phy_mode(struct usbhs_priv *priv)
+{
+	struct usbhs_mod_info *info = &priv->mod_info;
+
+	info->irq_vbus		= NULL;
+	priv->pfunc.get_vbus	= usbhsm_phy_get_vbus;
+
+	usbhs_irq_callback_update(priv, NULL);
+}
+
 /*
  *
  *		linux usb function
@@ -882,12 +906,28 @@ static int usbhsg_gadget_start(struct usb_gadget *gadget,
 {
 	struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
 	struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
+	struct device *dev = usbhs_priv_to_dev(priv);
+	int ret;
 
 	if (!driver		||
 	    !driver->setup	||
 	    driver->max_speed < USB_SPEED_FULL)
 		return -EINVAL;
 
+	/* connect to bus through transceiver */
+	if (!IS_ERR_OR_NULL(gpriv->transceiver)) {
+		ret = otg_set_peripheral(gpriv->transceiver->otg,
+					&gpriv->gadget);
+		if (ret) {
+			dev_err(dev, "%s: can't bind to transceiver\n",
+				gpriv->gadget.name);
+			return ret;
+		}
+
+		/* get vbus using phy versions */
+		usbhs_mod_phy_mode(priv);
+	}
+
 	/* first hook up the driver ... */
 	gpriv->driver = driver;
 
@@ -900,6 +940,10 @@ static int usbhsg_gadget_stop(struct usb_gadget *gadget)
 	struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
 
 	usbhsg_try_stop(priv, USBHSG_STATUS_REGISTERD);
+
+	if (!IS_ERR_OR_NULL(gpriv->transceiver))
+		otg_set_peripheral(gpriv->transceiver->otg, NULL);
+
 	gpriv->driver = NULL;
 
 	return 0;
@@ -947,12 +991,26 @@ static int usbhsg_set_selfpowered(struct usb_gadget *gadget, int is_self)
 	return 0;
 }
 
+static int usbhsg_vbus_session(struct usb_gadget *gadget, int is_active)
+{
+	struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget);
+	struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv);
+	struct platform_device *pdev = usbhs_priv_to_pdev(priv);
+
+	gpriv->vbus_active = !!is_active;
+
+	renesas_usbhs_call_notify_hotplug(pdev);
+
+	return 0;
+}
+
 static const struct usb_gadget_ops usbhsg_gadget_ops = {
 	.get_frame		= usbhsg_get_frame,
 	.set_selfpowered	= usbhsg_set_selfpowered,
 	.udc_start		= usbhsg_gadget_start,
 	.udc_stop		= usbhsg_gadget_stop,
 	.pullup			= usbhsg_pullup,
+	.vbus_session		= usbhsg_vbus_session,
 };
 
 static int usbhsg_start(struct usbhs_priv *priv)
@@ -994,6 +1052,10 @@ int usbhs_mod_gadget_probe(struct usbhs_priv *priv)
 		goto usbhs_mod_gadget_probe_err_gpriv;
 	}
 
+	gpriv->transceiver = usb_get_phy(USB_PHY_TYPE_UNDEFINED);
+	dev_info(dev, "%stransceiver found\n",
+		 gpriv->transceiver ? "" : "no ");
+
 	/*
 	 * CAUTION
 	 *