1/* 2 * BK Id: SCCS/s.delay.h 1.7 05/17/01 18:14:24 cort 3 */ 4#ifdef __KERNEL__ 5#ifndef _PPC_DELAY_H 6#define _PPC_DELAY_H 7 8#include <asm/param.h> 9 10/* 11 * Copyright 1996, Paul Mackerras. 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 */ 18 19extern unsigned long loops_per_jiffy; 20 21/* maximum permitted argument to udelay */ 22#define __MAX_UDELAY 1000000 23 24extern void __delay(unsigned int loops); 25 26/* N.B. the `secs' parameter here is a fixed-point number with 27 the binary point to the left of the most-significant bit. */ 28extern __inline__ void __const_udelay(unsigned int secs) 29{ 30 unsigned int loops; 31 32 __asm__("mulhwu %0,%1,%2" : "=r" (loops) : 33 "r" (secs), "r" (loops_per_jiffy)); 34 __delay(loops * HZ); 35} 36 37/* 38 * note that 4294 == 2^32 / 10^6, multiplying by 4294 converts from 39 * microseconds to a 32-bit fixed-point number of seconds. 40 */ 41extern __inline__ void __udelay(unsigned int usecs) 42{ 43 __const_udelay(usecs * 4294); 44} 45 46extern void __bad_udelay(void); /* deliberately undefined */ 47 48#define udelay(n) (__builtin_constant_p(n)? \ 49 ((n) > __MAX_UDELAY? __bad_udelay(): __const_udelay((n) * 4294u)) : \ 50 __udelay(n)) 51 52#endif /* defined(_PPC_DELAY_H) */ 53#endif /* __KERNEL__ */ 54