1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * OpenRISC Linux 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Linux architectural port borrowing liberally from similar works of 6*4882a593Smuzhiyun * others. All original copyrights apply as per the original source 7*4882a593Smuzhiyun * declaration. 8*4882a593Smuzhiyun * 9*4882a593Smuzhiyun * Modifications for the OpenRISC architecture: 10*4882a593Smuzhiyun * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 11*4882a593Smuzhiyun * 12*4882a593Smuzhiyun * Precise Delay Loops 13*4882a593Smuzhiyun */ 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun #include <linux/kernel.h> 16*4882a593Smuzhiyun #include <linux/export.h> 17*4882a593Smuzhiyun #include <linux/init.h> 18*4882a593Smuzhiyun #include <asm/param.h> 19*4882a593Smuzhiyun #include <asm/delay.h> 20*4882a593Smuzhiyun #include <asm/timex.h> 21*4882a593Smuzhiyun #include <asm/processor.h> 22*4882a593Smuzhiyun read_current_timer(unsigned long * timer_value)23*4882a593Smuzhiyunint read_current_timer(unsigned long *timer_value) 24*4882a593Smuzhiyun { 25*4882a593Smuzhiyun *timer_value = get_cycles(); 26*4882a593Smuzhiyun return 0; 27*4882a593Smuzhiyun } 28*4882a593Smuzhiyun __delay(unsigned long cycles)29*4882a593Smuzhiyunvoid __delay(unsigned long cycles) 30*4882a593Smuzhiyun { 31*4882a593Smuzhiyun cycles_t start = get_cycles(); 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun while ((get_cycles() - start) < cycles) 34*4882a593Smuzhiyun cpu_relax(); 35*4882a593Smuzhiyun } 36*4882a593Smuzhiyun EXPORT_SYMBOL(__delay); 37*4882a593Smuzhiyun __const_udelay(unsigned long xloops)38*4882a593Smuzhiyuninline void __const_udelay(unsigned long xloops) 39*4882a593Smuzhiyun { 40*4882a593Smuzhiyun unsigned long long loops; 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun loops = (unsigned long long)xloops * loops_per_jiffy * HZ; 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun __delay(loops >> 32); 45*4882a593Smuzhiyun } 46*4882a593Smuzhiyun EXPORT_SYMBOL(__const_udelay); 47*4882a593Smuzhiyun __udelay(unsigned long usecs)48*4882a593Smuzhiyunvoid __udelay(unsigned long usecs) 49*4882a593Smuzhiyun { 50*4882a593Smuzhiyun __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ 51*4882a593Smuzhiyun } 52*4882a593Smuzhiyun EXPORT_SYMBOL(__udelay); 53*4882a593Smuzhiyun __ndelay(unsigned long nsecs)54*4882a593Smuzhiyunvoid __ndelay(unsigned long nsecs) 55*4882a593Smuzhiyun { 56*4882a593Smuzhiyun __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ 57*4882a593Smuzhiyun } 58*4882a593Smuzhiyun EXPORT_SYMBOL(__ndelay); 59