diff options
Diffstat (limited to 'arch/openrisc/lib/delay.c')
-rw-r--r-- | arch/openrisc/lib/delay.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/openrisc/lib/delay.c b/arch/openrisc/lib/delay.c new file mode 100644 index 000000000000..01d9740ae6f3 --- /dev/null +++ b/arch/openrisc/lib/delay.c @@ -0,0 +1,60 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation + * + * Precise Delay Loops + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <asm/delay.h> +#include <asm/timex.h> +#include <asm/processor.h> + +int __devinit read_current_timer(unsigned long *timer_value) +{ + *timer_value = mfspr(SPR_TTCR); + return 0; +} + +void __delay(unsigned long cycles) +{ + cycles_t target = get_cycles() + cycles; + + while (get_cycles() < target) + cpu_relax(); +} +EXPORT_SYMBOL(__delay); + +inline void __const_udelay(unsigned long xloops) +{ + unsigned long long loops; + + loops = xloops * loops_per_jiffy * HZ; + + __delay(loops >> 32); +} +EXPORT_SYMBOL(__const_udelay); + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ +} +EXPORT_SYMBOL(__ndelay); |