usb: dwc2: gadget: Add handler for WkupAlert interrupt

Added interrupt handler for WkupAlert interrupt.

This interrupt should initiate Remote Wake up.
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/gadget.c

@@ -245,6 +245,27 @@ int dwc2_hsotg_tx_fifo_total_depth(struct dwc2_hsotg *hsotg)
 	return tx_addr_max - addr;
 }
 
+/**
+ * dwc2_gadget_wkup_alert_handler - Handler for WKUP_ALERT interrupt
+ *
+ * @hsotg: Programming view of the DWC_otg controller
+ *
+ */
+static void dwc2_gadget_wkup_alert_handler(struct dwc2_hsotg *hsotg)
+{
+	u32 gintsts2;
+	u32 gintmsk2;
+
+	gintsts2 = dwc2_readl(hsotg, GINTSTS2);
+	gintmsk2 = dwc2_readl(hsotg, GINTMSK2);
+
+	if (gintsts2 & GINTSTS2_WKUP_ALERT_INT) {
+		dev_dbg(hsotg->dev, "%s: Wkup_Alert_Int\n", __func__);
+		dwc2_clear_bit(hsotg, GINTSTS2, GINTSTS2_WKUP_ALERT_INT);
+		dwc2_set_bit(hsotg, DCFG, DCTL_RMTWKUPSIG);
+	}
+}
+
 /**
  * dwc2_hsotg_tx_fifo_average_depth - returns average depth of device mode
  * TX FIFOs
@@ -3730,6 +3751,10 @@ static irqreturn_t dwc2_hsotg_irq(int irq, void *pw)
 	if (gintsts & IRQ_RETRY_MASK && --retry_count > 0)
 		goto irq_retry;
 
+	/* Check WKUP_ALERT interrupt*/
+	if (hsotg->params.service_interval)
+		dwc2_gadget_wkup_alert_handler(hsotg);
+
 	spin_unlock(&hsotg->lock);
 
 	return IRQ_HANDLED;