1/*
 2 * Copyright (C) 1995-2004 Russell King
 3 *
 4 * Delay routines, using a pre-computed "loops_per_second" value.
 5 */
 6#ifndef __ASM_ARM_DELAY_H
 7#define __ASM_ARM_DELAY_H
 8
 
 9#include <asm/param.h>	/* HZ */
10
11extern void __delay(int loops);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12
13/*
14 * This function intentionally does not exist; if you see references to
15 * it, it means that you're calling udelay() with an out of range value.
16 *
17 * With currently imposed limits, this means that we support a max delay
18 * of 2000us. Further limits: HZ<=1000 and bogomips<=3355
19 */
20extern void __bad_udelay(void);
21
22/*
23 * division by multiplication: you don't have to worry about
24 * loss of precision.
25 *
26 * Use only for very small delays ( < 1 msec).  Should probably use a
27 * lookup table, really, as the multiplications take much too long with
28 * short delays.  This is a "reasonable" implementation, though (and the
29 * first constant multiplications gets optimized away if the delay is
30 * a constant)
31 */
32extern void __udelay(unsigned long usecs);
33extern void __const_udelay(unsigned long);
34
35#define MAX_UDELAY_MS 2
36
37#define udelay(n)							\
38	(__builtin_constant_p(n) ?					\
39	  ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() :		\
40			__const_udelay((n) * ((2199023U*HZ)>>11))) :	\
41	  __udelay(n))
 
 
 
 
 
 
 
 
 
 
 
42
43#endif /* defined(_ARM_DELAY_H) */
44

 1/*
 2 * Copyright (C) 1995-2004 Russell King
 3 *
 4 * Delay routines, using a pre-computed "loops_per_second" value.
 5 */
 6#ifndef __ASM_ARM_DELAY_H
 7#define __ASM_ARM_DELAY_H
 8
 9#include <asm/memory.h>
10#include <asm/param.h>	/* HZ */
11
12#define MAX_UDELAY_MS	2
13#define UDELAY_MULT	((UL(2199023) * HZ) >> 11)
14#define UDELAY_SHIFT	30
15
16#ifndef __ASSEMBLY__
17
18struct delay_timer {
19	unsigned long (*read_current_timer)(void);
20	unsigned long freq;
21};
22
23extern struct arm_delay_ops {
24	void (*delay)(unsigned long);
25	void (*const_udelay)(unsigned long);
26	void (*udelay)(unsigned long);
27	unsigned long ticks_per_jiffy;
28} arm_delay_ops;
29
30#define __delay(n)		arm_delay_ops.delay(n)
31
32/*
33 * This function intentionally does not exist; if you see references to
34 * it, it means that you're calling udelay() with an out of range value.
35 *
36 * With currently imposed limits, this means that we support a max delay
37 * of 2000us. Further limits: HZ<=1000 and bogomips<=3355
38 */
39extern void __bad_udelay(void);
40
41/*
42 * division by multiplication: you don't have to worry about
43 * loss of precision.
44 *
45 * Use only for very small delays ( < 2 msec).  Should probably use a
46 * lookup table, really, as the multiplications take much too long with
47 * short delays.  This is a "reasonable" implementation, though (and the
48 * first constant multiplications gets optimized away if the delay is
49 * a constant)
50 */
51#define __udelay(n)		arm_delay_ops.udelay(n)
52#define __const_udelay(n)	arm_delay_ops.const_udelay(n)
 
 
53
54#define udelay(n)							\
55	(__builtin_constant_p(n) ?					\
56	  ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() :		\
57			__const_udelay((n) * UDELAY_MULT)) :		\
58	  __udelay(n))
59
60/* Loop-based definitions for assembly code. */
61extern void __loop_delay(unsigned long loops);
62extern void __loop_udelay(unsigned long usecs);
63extern void __loop_const_udelay(unsigned long);
64
65/* Delay-loop timer registration. */
66#define ARCH_HAS_READ_CURRENT_TIMER
67extern void register_current_timer_delay(const struct delay_timer *timer);
68
69#endif /* __ASSEMBLY__ */
70
71#endif /* defined(_ARM_DELAY_H) */
72