69 lines
1.3 KiB
ArmAsm
69 lines
1.3 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/delay.S
|
|
*
|
|
* Copyright (C) 1995, 1996 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/delay.h>
|
|
.text
|
|
|
|
.LC0: .word loops_per_jiffy
|
|
.LC1: .word UDELAY_MULT
|
|
|
|
/*
|
|
* r0 <= 2000
|
|
* lpj <= 0x01ffffff (max. 3355 bogomips)
|
|
* HZ <= 1000
|
|
*/
|
|
|
|
ENTRY(__loop_udelay)
|
|
ldr r2, .LC1
|
|
mul r0, r2, r0
|
|
ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0x7fffff06
|
|
mov r1, #-1
|
|
ldr r2, .LC0
|
|
ldr r2, [r2] @ max = 0x01ffffff
|
|
add r0, r0, r1, lsr #32-14
|
|
mov r0, r0, lsr #14 @ max = 0x0001ffff
|
|
add r2, r2, r1, lsr #32-10
|
|
mov r2, r2, lsr #10 @ max = 0x00007fff
|
|
mul r0, r2, r0 @ max = 2^32-1
|
|
add r0, r0, r1, lsr #32-6
|
|
movs r0, r0, lsr #6
|
|
reteq lr
|
|
|
|
/*
|
|
* loops = r0 * HZ * loops_per_jiffy / 1000000
|
|
*/
|
|
.align 3
|
|
|
|
@ Delay routine
|
|
ENTRY(__loop_delay)
|
|
subs r0, r0, #1
|
|
#if 0
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
retls lr
|
|
subs r0, r0, #1
|
|
#endif
|
|
bhi __loop_delay
|
|
ret lr
|
|
ENDPROC(__loop_udelay)
|
|
ENDPROC(__loop_const_udelay)
|
|
ENDPROC(__loop_delay)
|