xhci: replace xhci_readl() with readl()

Function xhci_readl() is used to read 32bit xHC registers residing in MMIO
address space. It takes as first argument a pointer to the xhci_hcd although
it does not use it. xhci_readl() internally simply calls readl(). This creates
an illusion that xhci_readl() is an xhci specific function that has to be
called in a context where a pointer to xhci_hcd is available.

Remove the unnecessary xhci_readl() wrapper function and replace its calls to
with calls to readl() to make the code more straightforward.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 22da093..9f2349b 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -297,7 +297,7 @@
 	xhci_dbg(xhci, "// Ding dong!\n");
 	xhci_writel(xhci, DB_VALUE_HOST, &xhci->dba->doorbell[0]);
 	/* Flush PCI posted writes */
-	xhci_readl(xhci, &xhci->dba->doorbell[0]);
+	readl(&xhci->dba->doorbell[0]);
 }
 
 static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
@@ -1739,7 +1739,7 @@
 	faked_port_index = find_faked_portnum_from_hw_portnum(hcd, xhci,
 			port_id);
 
-	temp = xhci_readl(xhci, port_array[faked_port_index]);
+	temp = readl(port_array[faked_port_index]);
 	if (hcd->state == HC_STATE_SUSPENDED) {
 		xhci_dbg(xhci, "resume root hub\n");
 		usb_hcd_resume_root_hub(hcd);
@@ -1748,7 +1748,7 @@
 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
 		xhci_dbg(xhci, "port resume event for port %d\n", port_id);
 
-		temp1 = xhci_readl(xhci, &xhci->op_regs->command);
+		temp1 = readl(&xhci->op_regs->command);
 		if (!(temp1 & CMD_RUN)) {
 			xhci_warn(xhci, "xHC is not running.\n");
 			goto cleanup;
@@ -2831,7 +2831,7 @@
 
 	spin_lock(&xhci->lock);
 	/* Check if the xHC generated the interrupt, or the irq is shared */
-	status = xhci_readl(xhci, &xhci->op_regs->status);
+	status = readl(&xhci->op_regs->status);
 	if (status == 0xffffffff)
 		goto hw_died;
 
@@ -2860,7 +2860,7 @@
 	if (hcd->irq) {
 		u32 irq_pending;
 		/* Acknowledge the PCI interrupt */
-		irq_pending = xhci_readl(xhci, &xhci->ir_set->irq_pending);
+		irq_pending = readl(&xhci->ir_set->irq_pending);
 		irq_pending |= IMAN_IP;
 		xhci_writel(xhci, irq_pending, &xhci->ir_set->irq_pending);
 	}
@@ -3931,7 +3931,7 @@
 	if (ret)
 		return ret;
 
-	start_frame = xhci_readl(xhci, &xhci->run_regs->microframe_index);
+	start_frame = readl(&xhci->run_regs->microframe_index);
 	start_frame &= 0x3fff;
 
 	urb->start_frame = start_frame;