Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 *  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/param.h>
                .text

.LC0:           .word   loops_per_jiffy
.LC1:           .word   (2199023*HZ)>>11

/*
 * r0  <= 2000
 * lpj <= 0x01ffffff (max. 3355 bogomips)
 * HZ  <= 1000
 */

ENTRY(__udelay)
                ldr     r2, .LC1
                mul     r0, r2, r0
ENTRY(__const_udelay)                           @ 0 <= r0 <= 0x7fffff06
                ldr     r2, .LC0
                ldr     r2, [r2]                @ max = 0x01ffffff
                mov     r0, r0, lsr #14         @ max = 0x0001ffff
                mov     r2, r2, lsr #10         @ max = 0x00007fff
                mul     r0, r2, r0              @ max = 2^32-1
                movs    r0, r0, lsr #6
                moveq   pc, lr

/*
 * loops = r0 * HZ * loops_per_jiffy / 1000000
 *
 * Oh, if only we had a cycle counter...
 */

@ Delay routine
ENTRY(__delay)
                subs    r0, r0, #1
#if 0
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
                movls   pc, lr
                subs    r0, r0, #1
#endif
                bhi     __delay
                mov     pc, lr