usb: dwc2: Implement set_selfpowered()

dwc2 always reports as self-powered in response to a device status
request.  Implement the set_selfpowered() operations so that the gadget
can report as bus-powered when appropriate.

This is modelled on the dwc3 implementation.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc2/gadget.c

@@ -1646,7 +1646,8 @@ static int dwc2_hsotg_process_req_status(struct dwc2_hsotg *hsotg,
 
 	switch (ctrl->bRequestType & USB_RECIP_MASK) {
 	case USB_RECIP_DEVICE:
-		status = 1 << USB_DEVICE_SELF_POWERED;
+		status = hsotg->gadget.is_selfpowered <<
+			 USB_DEVICE_SELF_POWERED;
 		status |= hsotg->remote_wakeup_allowed <<
 			  USB_DEVICE_REMOTE_WAKEUP;
 		reply = cpu_to_le16(status);
@@ -4527,6 +4528,26 @@ static int dwc2_hsotg_gadget_getframe(struct usb_gadget *gadget)
 	return dwc2_hsotg_read_frameno(to_hsotg(gadget));
 }
 
+/**
+ * dwc2_hsotg_set_selfpowered - set if device is self/bus powered
+ * @gadget: The usb gadget state
+ * @is_selfpowered: Whether the device is self-powered
+ *
+ * Set if the device is self or bus powered.
+ */
+static int dwc2_hsotg_set_selfpowered(struct usb_gadget *gadget,
+				      int is_selfpowered)
+{
+	struct dwc2_hsotg *hsotg = to_hsotg(gadget);
+	unsigned long flags;
+
+	spin_lock_irqsave(&hsotg->lock, flags);
+	gadget->is_selfpowered = !!is_selfpowered;
+	spin_unlock_irqrestore(&hsotg->lock, flags);
+
+	return 0;
+}
+
 /**
  * dwc2_hsotg_pullup - connect/disconnect the USB PHY
  * @gadget: The usb gadget state
@@ -4618,6 +4639,7 @@ static int dwc2_hsotg_vbus_draw(struct usb_gadget *gadget, unsigned int mA)
 
 static const struct usb_gadget_ops dwc2_hsotg_gadget_ops = {
 	.get_frame	= dwc2_hsotg_gadget_getframe,
+	.set_selfpowered	= dwc2_hsotg_set_selfpowered,
 	.udc_start		= dwc2_hsotg_udc_start,
 	.udc_stop		= dwc2_hsotg_udc_stop,
 	.pullup                 = dwc2_hsotg_pullup,