/* * Precise Delay Loops for avr32 * * Copyright (C) 1993 Linus Torvalds * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> * Copyright (C) 2005-2006 Atmel Corporation * * 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. */ #include <linux/delay.h> #include <linux/module.h> #include <linux/timex.h> #include <linux/param.h> #include <linux/types.h> #include <linux/init.h> #include <asm/processor.h> #include <asm/sysreg.h> int read_current_timer(unsigned long *timer_value) { *timer_value = sysreg_read(COUNT); return 0; } void __delay(unsigned long loops) { unsigned bclock, now; bclock = sysreg_read(COUNT); do { now = sysreg_read(COUNT); } while ((now - bclock) < loops); } inline void __const_udelay(unsigned long xloops) { unsigned long long loops; asm("mulu.d %0, %1, %2" : "=r"(loops) : "r"(current_cpu_data.loops_per_jiffy * HZ), "r"(xloops)); __delay(loops >> 32); } void __udelay(unsigned long usecs) { __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ } void __ndelay(unsigned long nsecs) { __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ } |