USB: clean up some host controller sparse warnings

Fix usb sparse warnings:

drivers/usb/host/isp1362-hcd.c:2220:50: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:43:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:49:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:161:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:198:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:319:31: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:1231:33: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-pci.c:177:23: warning: non-ANSI function declaration of function 'xhci_register_pci'
drivers/usb/host/xhci-pci.c:182:26: warning: non-ANSI function declaration of function 'xhci_unregister_pci'
drivers/usb/host/xhci-ring.c:342:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:525:34: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1009:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1031:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1041:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1096:30: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1100:27: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:224:27: warning: symbol 'xhci_alloc_container_ctx' was not declared. Should it be static?
drivers/usb/host/xhci-mem.c:242:6: warning: symbol 'xhci_free_container_ctx' was not declared. Should it be static?

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off By: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/isp1362-hcd.c

@@ -2217,7 +2217,7 @@ static void create_debug_file(struct isp1362_hcd *isp1362_hcd)
 static void remove_debug_file(struct isp1362_hcd *isp1362_hcd)
 {
 	if (isp1362_hcd->pde)
-		remove_proc_entry(proc_filename, 0);
+		remove_proc_entry(proc_filename, NULL);
 }
 
 #endif

drivers/usb/host/xhci-mem.c

@@ -41,13 +41,13 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci, gfp_t flag
 
 	seg = kzalloc(sizeof *seg, flags);
 	if (!seg)
-		return 0;
+		return NULL;
 	xhci_dbg(xhci, "Allocating priv segment structure at %p\n", seg);
 
 	seg->trbs = dma_pool_alloc(xhci->segment_pool, flags, &dma);
 	if (!seg->trbs) {
 		kfree(seg);
-		return 0;
+		return NULL;
 	}
 	xhci_dbg(xhci, "// Allocating segment at %p (virtual) 0x%llx (DMA)\n",
 			seg->trbs, (unsigned long long)dma);
@@ -159,7 +159,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 	ring = kzalloc(sizeof *(ring), flags);
 	xhci_dbg(xhci, "Allocating ring at %p\n", ring);
 	if (!ring)
-		return 0;
+		return NULL;
 
 	INIT_LIST_HEAD(&ring->td_list);
 	if (num_segs == 0)
@@ -196,7 +196,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 
 fail:
 	xhci_ring_free(xhci, ring);
-	return 0;
+	return NULL;
 }
 
 void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
@@ -247,7 +247,7 @@ static void xhci_reinit_cached_ring(struct xhci_hcd *xhci,
 
 #define CTX_SIZE(_hcc) (HCC_64BYTE_CONTEXT(_hcc) ? 64 : 32)
 
-struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
+static struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 						    int type, gfp_t flags)
 {
 	struct xhci_container_ctx *ctx = kzalloc(sizeof(*ctx), flags);
@@ -265,7 +265,7 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 	return ctx;
 }
 
-void xhci_free_container_ctx(struct xhci_hcd *xhci,
+static void xhci_free_container_ctx(struct xhci_hcd *xhci,
 			     struct xhci_container_ctx *ctx)
 {
 	if (!ctx)
@@ -764,7 +764,7 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
 		xhci_free_container_ctx(xhci, dev->out_ctx);
 
 	kfree(xhci->devs[slot_id]);
-	xhci->devs[slot_id] = 0;
+	xhci->devs[slot_id] = NULL;
 }
 
 int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id,
@@ -1779,7 +1779,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 */
 	init_completion(&xhci->addr_dev);
 	for (i = 0; i < MAX_HC_SLOTS; ++i)
-		xhci->devs[i] = 0;
+		xhci->devs[i] = NULL;
 
 	if (scratchpad_alloc(xhci, flags))
 		goto fail;

drivers/usb/host/xhci-pci.c

@@ -177,12 +177,12 @@ static struct pci_driver xhci_pci_driver = {
 	.shutdown = 	usb_hcd_pci_shutdown,
 };
 
-int xhci_register_pci()
+int xhci_register_pci(void)
 {
 	return pci_register_driver(&xhci_pci_driver);
 }
 
-void xhci_unregister_pci()
+void xhci_unregister_pci(void)
 {
 	pci_unregister_driver(&xhci_pci_driver);
 }

drivers/usb/host/xhci-ring.c

@@ -388,7 +388,7 @@ static struct xhci_segment *find_trb_seg(
 		cur_seg = cur_seg->next;
 		if (cur_seg == start_seg)
 			/* Looped over the entire list.  Oops! */
-			return 0;
+			return NULL;
 	}
 	return cur_seg;
 }
@@ -582,7 +582,7 @@ static void handle_stopped_endpoint(struct xhci_hcd *xhci,
 	struct xhci_ring *ep_ring;
 	struct xhci_virt_ep *ep;
 	struct list_head *entry;
-	struct xhci_td *cur_td = 0;
+	struct xhci_td *cur_td = NULL;
 	struct xhci_td *last_unlinked_td;
 
 	struct xhci_dequeue_state deq_state;
@@ -1115,7 +1115,7 @@ struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
 
 	do {
 		if (start_dma == 0)
-			return 0;
+			return NULL;
 		/* We may get an event for a Link TRB in the middle of a TD */
 		end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
 				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
@@ -1137,7 +1137,7 @@ struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
 						 suspect_dma <= end_trb_dma))
 					return cur_seg;
 			}
-			return 0;
+			return NULL;
 		} else {
 			/* Might still be somewhere in this segment */
 			if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
@@ -1147,7 +1147,7 @@ struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
 		start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
 	} while (cur_seg != start_seg);
 
-	return 0;
+	return NULL;
 }
 
 static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
@@ -1223,11 +1223,11 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	struct xhci_ring *ep_ring;
 	unsigned int slot_id;
 	int ep_index;
-	struct xhci_td *td = 0;
+	struct xhci_td *td = NULL;
 	dma_addr_t event_dma;
 	struct xhci_segment *event_seg;
 	union xhci_trb *event_trb;
-	struct urb *urb = 0;
+	struct urb *urb = NULL;
 	int status = -EINPROGRESS;
 	struct xhci_ep_ctx *ep_ctx;
 	u32 trb_comp_code;