diff options
Diffstat (limited to 'arch/mips/lib/delay.c')
| -rw-r--r-- | arch/mips/lib/delay.c | 56 | 
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c new file mode 100644 index 000000000000..f69c6b569eb3 --- /dev/null +++ b/arch/mips/lib/delay.c @@ -0,0 +1,56 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License.  See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1994 by Waldorf Electronics + * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2007  Maciej W. Rozycki + */ +#include <linux/module.h> +#include <linux/param.h> +#include <linux/smp.h> + +#include <asm/compiler.h> +#include <asm/war.h> + +inline void __delay(unsigned int loops) +{ +	__asm__ __volatile__ ( +	"	.set	noreorder				\n" +	"	.align	3					\n" +	"1:	bnez	%0, 1b					\n" +	"	subu	%0, 1					\n" +	"	.set	reorder					\n" +	: "=r" (loops) +	: "0" (loops)); +} +EXPORT_SYMBOL(__delay); + +/* + * Division by multiplication: you don't have to worry about + * loss of precision. + * + * 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) + */ + +void __udelay(unsigned long us) +{ +	unsigned int lpj = current_cpu_data.udelay_val; + +	__delay((us * 0x000010c7 * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long ns) +{ +	unsigned int lpj = current_cpu_data.udelay_val; + +	__delay((us * 0x00000005 * HZ * lpj) >> 32); +} +EXPORT_SYMBOL(__ndelay);  | 
