usb: dwc2: disable external vbus supply when the device is removed

This patch adds an interface to disable the power in dwc2 driver.
This new interface is called when the device is removed.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

drivers/usb/host/dwc2.c

@@ -34,6 +34,9 @@ struct dwc2_priv {
 #ifdef CONFIG_DM_USB
 	uint8_t aligned_buffer[DWC2_DATA_BUF_SIZE] __aligned(ARCH_DMA_MINALIGN);
 	uint8_t status_buffer[DWC2_STATUS_BUF_SIZE] __aligned(ARCH_DMA_MINALIGN);
+#ifdef CONFIG_DM_REGULATOR
+	struct udevice *vbus_supply;
+#endif
 #else
 	uint8_t *aligned_buffer;
 	uint8_t *status_buffer;
@@ -168,16 +171,17 @@ static void dwc_otg_core_reset(struct dwc2_core_regs *regs)
 #if defined(CONFIG_DM_USB) && defined(CONFIG_DM_REGULATOR)
 static int dwc_vbus_supply_init(struct udevice *dev)
 {
-	struct udevice *vbus_supply;
+	struct dwc2_priv *priv = dev_get_priv(dev);
 	int ret;
 
-	ret = device_get_supply_regulator(dev, "vbus-supply", &vbus_supply);
+	ret = device_get_supply_regulator(dev, "vbus-supply",
+					  &priv->vbus_supply);
 	if (ret) {
 		debug("%s: No vbus supply\n", dev->name);
 		return 0;
 	}
 
-	ret = regulator_set_enable(vbus_supply, true);
+	ret = regulator_set_enable(priv->vbus_supply, true);
 	if (ret) {
 		pr_err("Error enabling vbus supply\n");
 		return ret;
@@ -185,11 +189,34 @@ static int dwc_vbus_supply_init(struct udevice *dev)
 
 	return 0;
 }
+
+static int dwc_vbus_supply_exit(struct udevice *dev)
+{
+	struct dwc2_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	if (priv->vbus_supply) {
+		ret = regulator_set_enable(priv->vbus_supply, false);
+		if (ret) {
+			dev_err(dev, "Error disabling vbus supply\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
 #else
 static int dwc_vbus_supply_init(struct udevice *dev)
 {
 	return 0;
 }
+
+#if defined(CONFIG_DM_USB)
+static int dwc_vbus_supply_exit(struct udevice *dev)
+{
+	return 0;
+}
+#endif
 #endif
 
 /*
@@ -1269,6 +1296,11 @@ static int dwc2_usb_probe(struct udevice *dev)
 static int dwc2_usb_remove(struct udevice *dev)
 {
 	struct dwc2_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = dwc_vbus_supply_exit(dev);
+	if (ret)
+		return ret;
 
 	dwc2_uninit_common(priv->regs);