Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.9 / 7c9f4e3aaae020fc674f52393cbac1bdb648bf90 / . / arch / arm / lib / delay.S
blob: 930a7025922077a0b1da5cb048bdc4041bbceed0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/*
2 * linux/arch/arm/lib/delay.S
3 *
4 * Copyright (C) 1995, 1996 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <asm/assembler.h>
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]12#include <asm/param.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]13 .text
14
Nicolas Pitre8adbb372005-11-11 21:51:49 +0000[diff] [blame]15.LC0: .word loops_per_jiffy
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]16.LC1: .word (2199023*HZ)>>11
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]17
18/*
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]19 * r0 <= 2000
20 * lpj <= 0x01ffffff (max. 3355 bogomips)
21 * HZ <= 1000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]22 */
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]23
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]24ENTRY(__udelay)
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]25 ldr r2, .LC1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]26 mul r0, r2, r0
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]27ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
Nicolas Pitre8adbb372005-11-11 21:51:49 +0000[diff] [blame]28 ldr r2, .LC0
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]29 ldr r2, [r2] @ max = 0x01ffffff
30 mov r0, r0, lsr #14 @ max = 0x0001ffff
31 mov r2, r2, lsr #10 @ max = 0x00007fff
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]32 mul r0, r2, r0 @ max = 2^32-1
33 movs r0, r0, lsr #6
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]34 moveq pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]35
36/*
Peter Teichmann6d4518d2006-03-20 17:10:09 +0000[diff] [blame]37 * loops = r0 * HZ * loops_per_jiffy / 1000000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]38 *
39 * Oh, if only we had a cycle counter...
40 */
41
42@ Delay routine
43ENTRY(__delay)
44 subs r0, r0, #1
45#if 0
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]46 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]47 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]48 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]49 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]50 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]51 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]52 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]53 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]54 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]55 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]56 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]57 subs r0, r0, #1
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]58 movls pc, lr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]59 subs r0, r0, #1
60#endif
61 bhi __delay
Russell King7999d8d2006-06-25 11:17:23 +0100[diff] [blame]62 mov pc, lr