File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/powerpc/sysdev/qe_lib/usb.c b/arch/powerpc/sysdev/qe_lib/usb.c
new file mode 100644
index 0000000..27f23bd
--- /dev/null
+++ b/arch/powerpc/sysdev/qe_lib/usb.c
@@ -0,0 +1,56 @@
+/*
+ * QE USB routines
+ *
+ * Copyright 2006 Freescale Semiconductor, Inc.
+ *               Shlomi Gridish <gridish@freescale.com>
+ *               Jerry Huang <Chang-Ming.Huang@freescale.com>
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *               Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <asm/immap_qe.h>
+#include <asm/qe.h>
+
+int qe_usb_clock_set(enum qe_clock clk, int rate)
+{
+	struct qe_mux __iomem *mux = &qe_immr->qmx;
+	unsigned long flags;
+	u32 val;
+
+	switch (clk) {
+	case QE_CLK3:  val = QE_CMXGCR_USBCS_CLK3;  break;
+	case QE_CLK5:  val = QE_CMXGCR_USBCS_CLK5;  break;
+	case QE_CLK7:  val = QE_CMXGCR_USBCS_CLK7;  break;
+	case QE_CLK9:  val = QE_CMXGCR_USBCS_CLK9;  break;
+	case QE_CLK13: val = QE_CMXGCR_USBCS_CLK13; break;
+	case QE_CLK17: val = QE_CMXGCR_USBCS_CLK17; break;
+	case QE_CLK19: val = QE_CMXGCR_USBCS_CLK19; break;
+	case QE_CLK21: val = QE_CMXGCR_USBCS_CLK21; break;
+	case QE_BRG9:  val = QE_CMXGCR_USBCS_BRG9;  break;
+	case QE_BRG10: val = QE_CMXGCR_USBCS_BRG10; break;
+	default:
+		pr_err("%s: requested unknown clock %d\n", __func__, clk);
+		return -EINVAL;
+	}
+
+	if (qe_clock_is_brg(clk))
+		qe_setbrg(clk, rate, 1);
+
+	spin_lock_irqsave(&cmxgcr_lock, flags);
+
+	clrsetbits_be32(&mux->cmxgcr, QE_CMXGCR_USBCS, val);
+
+	spin_unlock_irqrestore(&cmxgcr_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(qe_usb_clock_set);