#ifndef _M68KNOMMU_DELAY_H #define _M68KNOMMU_DELAY_H #include /* * Copyright (C) 1994 Hamish Macdonald * * Delay routines, using a pre-computed "loops_per_second" value. */ extern __inline__ void __delay(unsigned long loops) { #if defined(CONFIG_COLDFIRE) /* The coldfire runs this loop at significantly different speeds * depending upon long word alignment or not. We'll pad it to * long word alignment which is the faster version. * The 0x4a8e is of course a 'tstl %fp' instruction. This is better * than using a NOP (0x4e71) instruction because it executes in one * cycle not three and doesn't allow for an arbitary delay waiting * for bus cycles to finish. Also fp/a6 isn't likely to cause a * stall waiting for the register to become valid if such is added * to the coldfire at some stage. */ __asm__ __volatile__ ( ".balignw 4, 0x4a8e\n\t" "1: subql #1, %0\n\t" "jcc 1b" : "=d" (loops) : "0" (loops)); #else __asm__ __volatile__ ( "1: subql #1, %0\n\t" "jcc 1b" : "=d" (loops) : "0" (loops)); #endif } /* * Use only for very small delays ( < 1 msec). Should probably use a * lookup table, really, as the multiplications take much too long with * short delays. This is a "reasonable" implementation, though (and the * first constant multiplications gets optimized away if the delay is * a constant) */ extern unsigned long loops_per_jiffy; extern __inline__ void udelay(unsigned long usecs) { #ifdef CONFIG_M68332 usecs *= 0x000010c6; __asm__ __volatile__ ("mulul %1,%0:%2" : "=d" (usecs) : "d" (usecs), "d" (loops_per_jiffy*HZ)); __delay(usecs); #elif defined(CONFIG_M68328) || defined(CONFIG_M68EZ328) || \ defined(CONFIG_COLDFIRE) || defined(CONFIG_M68360) || \ defined(CONFIG_M68VZ328) register unsigned long full_loops, part_loops; full_loops = ((usecs * HZ) / 1000000) * loops_per_jiffy; usecs %= (1000000 / HZ); part_loops = (usecs * HZ * loops_per_jiffy) / 1000000; __delay(full_loops + part_loops); #else unsigned long tmp; usecs *= 4295; /* 2**32 / 1000000 */ __asm__ ("mulul %2,%0:%1" : "=d" (usecs), "=d" (tmp) : "d" (usecs), "1" (loops_per_jiffy*HZ)); __delay(usecs); #endif } #endif /* defined(_M68KNOMMU_DELAY_H) */