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Wolfgang Denk6cb142f2006-03-12 02:12:27 +01001/*
2 * U-boot - delay.h Routines for introducing delays
3 *
Aubrey Li155fd762007-04-05 18:31:18 +08004 * Copyright (c) 2005-2007 Analog Devices Inc.
Wolfgang Denk6cb142f2006-03-12 02:12:27 +01005 *
6 * See file CREDITS for list of people who contributed to this
7 * project.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
Aubrey Li155fd762007-04-05 18:31:18 +080021 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
22 * MA 02110-1301 USA
Wolfgang Denk6cb142f2006-03-12 02:12:27 +010023 */
24
25#ifndef _BLACKFIN_DELAY_H
26#define _BLACKFIN_DELAY_H
27
28/*
29 * Changes made by akbar.hussain@Lineo.com, for BLACKFIN
30 * Copyright (C) 1994 Hamish Macdonald
31 *
32 * Delay routines, using a pre-computed "loops_per_second" value.
33 */
34
35extern __inline__ void __delay(unsigned long loops)
36{
37 __asm__ __volatile__("1:\t%0 += -1;\n\t"
Aubrey.Li3f0606a2007-03-09 13:38:44 +080038 "cc = %0 == 0;\n\t"
39 "if ! cc jump 1b;\n":"=d"(loops)
40 :"0"(loops));
Wolfgang Denk6cb142f2006-03-12 02:12:27 +010041}
42
43/*
44 * Use only for very small delays ( < 1 msec). Should probably use a
45 * lookup table, really, as the multiplications take much too long with
46 * short delays. This is a "reasonable" implementation, though (and the
47 * first constant multiplications gets optimized away if the delay is
48 * a constant)
49 */
50extern __inline__ void udelay(unsigned long usecs)
51{
52 __delay(usecs);
53}
54
55#endif