usb: gadget: ci13xxx: don't use "advance" feature when setting address

Newer versions of the chipidea controller support the "advance" setting
of usb address, which means instead of setting it immediately, deferring
it till the status completion. Unfortunately, older versions of the
controller don't have this feature, so in order to support those too, we
simply don't use it. It's about 4 lines of extra code, and isn't in any
way critical to performance. While at it, change the return value of the
hw_usb_set_address() to void, since it can't fail in any measurable way.

With this patch, ci13xxx_udc driver works with the chipidea controller in
kirkwood (feroceon SoC), as found in, for example, sheevaplug.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/ci13xxx_udc.c

@@ -722,14 +722,13 @@ static int hw_test_and_set_setup_guard(struct ci13xxx *udc)
  * hw_usb_set_address: configures USB address (execute without interruption)
  * @value: new USB address
  *
- * This function returns an error code
+ * This function explicitly sets the address, without the "USBADRA" (advance)
+ * feature, which is not supported by older versions of the controller.
  */
-static int hw_usb_set_address(struct ci13xxx *udc, u8 value)
+static void hw_usb_set_address(struct ci13xxx *udc, u8 value)
 {
-	/* advance */
-	hw_write(udc, OP_DEVICEADDR, DEVICEADDR_USBADR | DEVICEADDR_USBADRA,
-		  value << ffs_nr(DEVICEADDR_USBADR) | DEVICEADDR_USBADRA);
-	return 0;
+	hw_write(udc, OP_DEVICEADDR, DEVICEADDR_USBADR,
+		 value << ffs_nr(DEVICEADDR_USBADR));
 }
 
 /**
@@ -1803,6 +1802,11 @@ isr_setup_status_complete(struct usb_ep *ep, struct usb_request *req)
 	struct ci13xxx *udc = req->context;
 	unsigned long flags;
 
+	if (udc->setaddr) {
+		hw_usb_set_address(udc, udc->address);
+		udc->setaddr = false;
+	}
+
 	spin_lock_irqsave(&udc->lock, flags);
 	if (udc->test_mode)
 		hw_port_test_set(udc, udc->test_mode);
@@ -1990,10 +1994,8 @@ __acquires(udc->lock)
 			if (le16_to_cpu(req.wLength) != 0 ||
 			    le16_to_cpu(req.wIndex)  != 0)
 				break;
-			err = hw_usb_set_address(udc,
-						 (u8)le16_to_cpu(req.wValue));
-			if (err)
-				break;
+			udc->address = (u8)le16_to_cpu(req.wValue);
+			udc->setaddr = true;
 			err = isr_setup_status_phase(udc);
 			break;
 		case USB_REQ_SET_FEATURE:

drivers/usb/gadget/ci13xxx_udc.h

@@ -141,6 +141,8 @@ struct ci13xxx {
 	struct ci13xxx_ep          *ep0out, *ep0in;
 	unsigned		   hw_ep_max;  /* number of hw endpoints */
 
+	bool			   setaddr;
+	u8			   address;
 	u8                         remote_wakeup; /* Is remote wakeup feature
 							enabled by the host? */
 	u8                         suspended;  /* suspended by the host */