usb: dwc3: gadget: rename busy/free_slot to trb_enqueue/dequeue

This makes it clear that we're dealing with a queue
of TRBs. No functional changes. While at that, also
rename start_slot to first_trb_index for similar
reasons.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.h

@@ -449,8 +449,8 @@ struct dwc3_event_buffer {
  * @started_list: list of started requests on this endpoint
  * @trb_pool: array of transaction buffers
  * @trb_pool_dma: dma address of @trb_pool
- * @free_slot: next slot which is going to be used
- * @busy_slot: first slot which is owned by HW
+ * @trb_enqueue: enqueue 'pointer' into TRB array
+ * @trb_dequeue: dequeue 'pointer' into TRB array
  * @desc: usb_endpoint_descriptor pointer
  * @dwc: pointer to DWC controller
  * @saved_state: ep state saved during hibernation
@@ -470,8 +470,8 @@ struct dwc3_ep {
 
 	struct dwc3_trb		*trb_pool;
 	dma_addr_t		trb_pool_dma;
-	u32			free_slot;
-	u32			busy_slot;
+	u32			trb_enqueue;
+	u32			trb_dequeue;
 	const struct usb_ss_ep_comp_descriptor *comp_desc;
 	struct dwc3		*dwc;
 
@@ -628,7 +628,7 @@ struct dwc3_request {
 	struct usb_request	request;
 	struct list_head	list;
 	struct dwc3_ep		*dep;
-	u32			start_slot;
+	u32			first_trb_index;
 
 	u8			epnum;
 	struct dwc3_trb		*trb;

drivers/usb/dwc3/ep0.c

@@ -70,10 +70,10 @@ static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
 		return 0;
 	}
 
-	trb = &dwc->ep0_trb[dep->free_slot];
+	trb = &dwc->ep0_trb[dep->trb_enqueue];
 
 	if (chain)
-		dep->free_slot++;
+		dep->trb_enqueue++;
 
 	trb->bpl = lower_32_bits(buf_dma);
 	trb->bph = upper_32_bits(buf_dma);
@@ -845,7 +845,7 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
 			trb++;
 			length = trb->size & DWC3_TRB_SIZE_MASK;
 
-			ep0->free_slot = 0;
+			ep0->trb_enqueue = 0;
 		}
 
 		transfer_size = roundup((ur->length - transfer_size),

drivers/usb/dwc3/gadget.c

@@ -154,16 +154,16 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 	if (req->started) {
 		i = 0;
 		do {
-			dep->busy_slot++;
+			dep->trb_dequeue++;
 			/*
 			 * Skip LINK TRB. We can't use req->trb and check for
 			 * DWC3_TRBCTL_LINK_TRB because it points the TRB we
 			 * just completed (not the LINK TRB).
 			 */
-			if (((dep->busy_slot & DWC3_TRB_MASK) ==
+			if (((dep->trb_dequeue & DWC3_TRB_MASK) ==
 				DWC3_TRB_NUM- 1) &&
 				usb_endpoint_xfer_isoc(dep->endpoint.desc))
-				dep->busy_slot++;
+				dep->trb_dequeue++;
 		} while(++i < req->request.num_mapped_sgs);
 		req->started = false;
 	}
@@ -741,20 +741,20 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 			chain ? " chain" : "");
 
 
-	trb = &dep->trb_pool[dep->free_slot & DWC3_TRB_MASK];
+	trb = &dep->trb_pool[dep->trb_enqueue & DWC3_TRB_MASK];
 
 	if (!req->trb) {
 		dwc3_gadget_move_started_request(req);
 		req->trb = trb;
 		req->trb_dma = dwc3_trb_dma_offset(dep, trb);
-		req->start_slot = dep->free_slot & DWC3_TRB_MASK;
+		req->first_trb_index = dep->trb_enqueue & DWC3_TRB_MASK;
 	}
 
-	dep->free_slot++;
+	dep->trb_enqueue++;
 	/* Skip the LINK-TRB on ISOC */
-	if (((dep->free_slot & DWC3_TRB_MASK) == DWC3_TRB_NUM - 1) &&
+	if (((dep->trb_enqueue & DWC3_TRB_MASK) == DWC3_TRB_NUM - 1) &&
 			usb_endpoint_xfer_isoc(dep->endpoint.desc))
-		dep->free_slot++;
+		dep->trb_enqueue++;
 
 	trb->size = DWC3_TRB_SIZE_LENGTH(length);
 	trb->bpl = lower_32_bits(dma);
@@ -826,11 +826,11 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting)
 	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
 
 	/* the first request must not be queued */
-	trbs_left = (dep->busy_slot - dep->free_slot) & DWC3_TRB_MASK;
+	trbs_left = (dep->trb_dequeue - dep->trb_enqueue) & DWC3_TRB_MASK;
 
 	/* Can't wrap around on a non-isoc EP since there's no link TRB */
 	if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
-		max = DWC3_TRB_NUM - (dep->free_slot & DWC3_TRB_MASK);
+		max = DWC3_TRB_NUM - (dep->trb_enqueue & DWC3_TRB_MASK);
 		if (trbs_left > max)
 			trbs_left = max;
 	}
@@ -856,11 +856,11 @@ static void dwc3_prepare_trbs(struct dwc3_ep *dep, bool starting)
 		 * don't wrap around we have to start at the beginning.
 		 */
 		if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
-			dep->busy_slot = 1;
-			dep->free_slot = 1;
+			dep->trb_dequeue = 1;
+			dep->trb_enqueue = 1;
 		} else {
-			dep->busy_slot = 0;
-			dep->free_slot = 0;
+			dep->trb_dequeue = 0;
+			dep->trb_enqueue = 0;
 		}
 	}
 
@@ -1931,7 +1931,7 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
 
 		i = 0;
 		do {
-			slot = req->start_slot + i;
+			slot = req->first_trb_index + i;
 			if ((slot == DWC3_TRB_NUM - 1) &&
 				usb_endpoint_xfer_isoc(dep->endpoint.desc))
 				slot++;