52 lines
1.1 KiB
ArmAsm
52 lines
1.1 KiB
ArmAsm
|
/*
|
||
|
|
* linux/arch/unicore32/lib/delay.S
|
||
|
|
*
|
||
|
|
* Code specific to PKUnity SoC and UniCore ISA
|
||
|
|
*
|
||
|
|
* Copyright (C) 2001-2010 GUAN Xue-tao
|
||
|
|
*
|
||
|
|
* 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/param.h>
|
||
|
|
.text
|
||
|
|
|
||
|
|
.LC0: .word loops_per_jiffy
|
||
|
|
.LC1: .word (2199023*HZ)>>11
|
||
|
|
|
||
|
|
/*
|
||
|
|
* r0 <= 2000
|
||
|
|
* lpj <= 0x01ffffff (max. 3355 bogomips)
|
||
|
|
* HZ <= 1000
|
||
|
|
*/
|
||
|
|
|
||
|
|
ENTRY(__udelay)
|
||
|
|
ldw r2, .LC1
|
||
|
|
mul r0, r2, r0
|
||
|
|
ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
|
||
|
|
ldw r2, .LC0
|
||
|
|
ldw r2, [r2] @ max = 0x01ffffff
|
||
|
|
mov r0, r0 >> #14 @ max = 0x0001ffff
|
||
|
|
mov r2, r2 >> #10 @ max = 0x00007fff
|
||
|
|
mul r0, r2, r0 @ max = 2^32-1
|
||
|
|
mov.a r0, r0 >> #6
|
||
|
|
cmoveq pc, lr
|
||
|
|
|
||
|
|
/*
|
||
|
|
* loops = r0 * HZ * loops_per_jiffy / 1000000
|
||
|
|
*
|
||
|
|
* Oh, if only we had a cycle counter...
|
||
|
|
*/
|
||
|
|
|
||
|
|
@ Delay routine
|
||
|
|
ENTRY(__delay)
|
||
|
|
sub.a r0, r0, #2
|
||
|
|
bua __delay
|
||
|
|
mov pc, lr
|
||
|
|
ENDPROC(__udelay)
|
||
|
|
ENDPROC(__const_udelay)
|
||
|
|
ENDPROC(__delay)
|