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Diffstat (limited to 'arch/frv/include/asm/delay.h')
-rw-r--r-- | arch/frv/include/asm/delay.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/frv/include/asm/delay.h b/arch/frv/include/asm/delay.h new file mode 100644 index 0000000..597b4eb --- /dev/null +++ b/arch/frv/include/asm/delay.h @@ -0,0 +1,50 @@ +/* delay.h: FRV delay code + * + * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _ASM_DELAY_H +#define _ASM_DELAY_H + +#include <asm/param.h> +#include <asm/timer-regs.h> + +/* + * delay loop - runs at __core_clock_speed_HZ / 2 [there are 2 insns in the loop] + */ +extern unsigned long __delay_loops_MHz; + +static inline void __delay(unsigned long loops) +{ + asm volatile("1: subicc %0,#1,%0,icc0 \n" + " bnc icc0,#2,1b \n" + : "=r" (loops) + : "0" (loops) + : "icc0" + ); +} + +/* + * 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; + +static inline void udelay(unsigned long usecs) +{ + __delay(usecs * __delay_loops_MHz); +} + +#define ndelay(n) udelay((n) * 5) + +#endif /* _ASM_DELAY_H */ |