1 /* delay.h: FRV delay code
2 *
3 * Copyright (C) 2003 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 License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #ifndef _ASM_DELAY_H
13 #define _ASM_DELAY_H
14
15 #include <asm/param.h>
16 #include <asm/timer-regs.h>
17
18 /*
19 * delay loop - runs at __core_clock_speed_HZ / 2 [there are 2 insns in the loop]
20 */
21 extern unsigned long __delay_loops_MHz;
22
__delay(unsigned long loops)23 static inline void __delay(unsigned long loops)
24 {
25 asm volatile("1: subicc %0,#1,%0,icc0 \n"
26 " bnc icc0,#2,1b \n"
27 : "=r" (loops)
28 : "0" (loops)
29 : "icc0"
30 );
31 }
32
33 /*
34 * Use only for very small delays ( < 1 msec). Should probably use a
35 * lookup table, really, as the multiplications take much too long with
36 * short delays. This is a "reasonable" implementation, though (and the
37 * first constant multiplications gets optimized away if the delay is
38 * a constant)
39 */
40
41 extern unsigned long loops_per_jiffy;
42
udelay(unsigned long usecs)43 static inline void udelay(unsigned long usecs)
44 {
45 __delay(usecs * __delay_loops_MHz);
46 }
47
48 #define ndelay(n) udelay((n) * 5)
49
50 #endif /* _ASM_DELAY_H */
51