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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [arm/] [lib/] [delay.S] - Blame information for rev 3

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1 3 xianfeng 
/*
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 *  linux/arch/arm/lib/delay.S
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 *
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 *  Copyright (C) 1995, 1996 Russell King
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include
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#include
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#include
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                .text
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.LC0:           .word   loops_per_jiffy
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.LC1:           .word   (2199023*HZ)>>11
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/*
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 * r0  <= 2000
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 * lpj <= 0x01ffffff (max. 3355 bogomips)
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 * HZ  <= 1000
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 */
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ENTRY(__udelay)
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                ldr     r2, .LC1
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                mul     r0, r2, r0
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ENTRY(__const_udelay)                           @ 0 <= r0 <= 0x7fffff06
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                ldr     r2, .LC0
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                ldr     r2, [r2]                @ max = 0x01ffffff
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                mov     r0, r0, lsr #14         @ max = 0x0001ffff
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                mov     r2, r2, lsr #10         @ max = 0x00007fff
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                mul     r0, r2, r0              @ max = 2^32-1
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                movs    r0, r0, lsr #6
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                moveq   pc, lr
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/*
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 * loops = r0 * HZ * loops_per_jiffy / 1000000
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 *
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 * Oh, if only we had a cycle counter...
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 */
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@ Delay routine
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ENTRY(__delay)
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                subs    r0, r0, #1
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#if 0
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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                movls   pc, lr
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                subs    r0, r0, #1
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#endif
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                bhi     __delay
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                mov     pc, lr

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