usb: dwc3: gadget: add frame number mask

This patch adds a define DWC3_FRNUMBER_MASK for the commonly used
0x3fff mask and uses it.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/gadget.c

@@ -1403,7 +1403,7 @@ static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep)
 		 * Check if we can start isoc transfer on the next interval or
 		 * 4 uframes in the future with BIT[15:14] as dep->combo_num
 		 */
-		test_frame_number = dep->frame_number & 0x3fff;
+		test_frame_number = dep->frame_number & DWC3_FRNUMBER_MASK;
 		test_frame_number |= dep->combo_num << 14;
 		test_frame_number += max_t(u32, 4, dep->interval);
 
@@ -1450,7 +1450,7 @@ static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep)
 	else if (test0 && test1)
 		dep->combo_num = 0;
 
-	dep->frame_number &= 0x3fff;
+	dep->frame_number &= DWC3_FRNUMBER_MASK;
 	dep->frame_number |= dep->combo_num << 14;
 	dep->frame_number += max_t(u32, 4, dep->interval);
 

drivers/usb/dwc3/gadget.h

@@ -54,6 +54,8 @@ struct dwc3;
 /* U2 Device exit Latency */
 #define DWC3_DEFAULT_U2_DEV_EXIT_LAT	0x1FF	/* Less then 511 microsec */
 
+/* Frame/Microframe Number Mask */
+#define DWC3_FRNUMBER_MASK		0x3fff
 /* -------------------------------------------------------------------------- */
 
 #define to_dwc3_request(r)	(container_of(r, struct dwc3_request, request))