1 /*
2 * arch/sh/lib64/udelay.c
3 *
4 * Delay routines, using a pre-computed "loops_per_jiffy" value.
5 *
6 * Copyright (C) 2000, 2001 Paolo Alberelli
7 * Copyright (C) 2003, 2004 Paul Mundt
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13 #include <linux/sched.h>
14 #include <asm/param.h>
15
16 /*
17 * Use only for very small delays (< 1 msec).
18 *
19 * The active part of our cycle counter is only 32-bits wide, and
20 * we're treating the difference between two marks as signed. On
21 * a 1GHz box, that's about 2 seconds.
22 */
23
__delay(unsigned long loops)24 void __delay(unsigned long loops)
25 {
26 long long dummy;
27 __asm__ __volatile__("gettr tr0, %1\n\t"
28 "pta $+4, tr0\n\t"
29 "addi %0, -1, %0\n\t"
30 "bne %0, r63, tr0\n\t"
31 "ptabs %1, tr0\n\t":"=r"(loops),
32 "=r"(dummy)
33 :"0"(loops));
34 }
35
__const_udelay(unsigned long xloops)36 void __const_udelay(unsigned long xloops)
37 {
38 __delay(xloops * (HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy));
39 }
40
__udelay(unsigned long usecs)41 void __udelay(unsigned long usecs)
42 {
43 __const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
44 }
45
__ndelay(unsigned long nsecs)46 void __ndelay(unsigned long nsecs)
47 {
48 __const_udelay(nsecs * 0x00000005);
49 }
50