usb: xhci-dbg: Display endpoint number and direction in context dump

When CONFIG_XHCI_HCD_DEBUGGING is activated, the XHCI driver can dump
device and input contexts to the console. The endpoint contexts in that
dump are labeled "Endpoint N Context", where N is the XHCI endpoint
index (DCI - 1). This can be very confusing, especially for people who
are not that familiar with the XHCI specification. This patch introduces
an xhci_get_endpoint_address function (as a counterpart to the reverse
xhci_get_endpoint_index), and uses it to additionally display the
endpoint number and direction when dumping contexts, which are much more
commonly used concepts in USB.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-dbg.c b/drivers/usb/host/xhci-dbg.c
index 5f3a7c7..f2e7689 100644
--- a/drivers/usb/host/xhci-dbg.c
+++ b/drivers/usb/host/xhci-dbg.c
@@ -503,11 +503,14 @@
 	if (last_ep < 31)
 		last_ep_ctx = last_ep + 1;
 	for (i = 0; i < last_ep_ctx; ++i) {
+		unsigned int epaddr = xhci_get_endpoint_address(i);
 		struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, ctx, i);
 		dma_addr_t dma = ctx->dma +
 			((unsigned long)ep_ctx - (unsigned long)ctx->bytes);
 
-		xhci_dbg(xhci, "Endpoint %02d Context:\n", i);
+		xhci_dbg(xhci, "%s Endpoint %02d Context (ep_index %02d):\n",
+				usb_endpoint_out(epaddr) ? "OUT" : "IN",
+				epaddr & USB_ENDPOINT_NUMBER_MASK, i);
 		xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - ep_info\n",
 				&ep_ctx->ep_info,
 				(unsigned long long)dma, ep_ctx->ep_info);