1/* MN10300 Short delay interpolation routines
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/delay.h>
14#include <asm/div64.h>
15
16/*
17 * basic delay loop
18 */
19void __delay(unsigned long loops)
20{
21	int d0;
22
23	asm volatile(
24		"	bra	1f	\n"
25		"	.align	4	\n"
26		"1:	bra	2f	\n"
27		"	.align	4	\n"
28		"2:	add	-1,%0	\n"
29		"	bne	2b	\n"
30		: "=&d" (d0)
31		: "0" (loops)
32		: "cc");
33}
34EXPORT_SYMBOL(__delay);
35
36/*
37 * handle a delay specified in terms of microseconds
38 */
39void __udelay(unsigned long usecs)
40{
41	unsigned long start, stop, cnt;
42
43	/* usecs * CLK / 1E6 */
44	stop = __muldiv64u(usecs, MN10300_TSCCLK, 1000000);
45	start = TMTSCBC;
46
47	do {
48		cnt = start - TMTSCBC;
49	} while (cnt < stop);
50}
51EXPORT_SYMBOL(__udelay);
52