arch/nios2/lib/delay.c

   1 /* Copyright Altera Corporation (C) 2014. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License, version 2,
   5  * as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <asm/delay.h>
  19 #include <asm/param.h>
  20 #include <asm/processor.h>
  21 #include <asm/timex.h>
  22
  23 void __delay(unsigned long cycles)
  24 {
  25         cycles_t start = get_cycles();
  26
  27         while ((get_cycles() - start) < cycles)
  28                 cpu_relax();
  29 }
  30 EXPORT_SYMBOL(__delay);
  31
  32 void __const_udelay(unsigned long xloops)
  33 {
  34         u64 loops;
  35
  36         loops = (u64)xloops * loops_per_jiffy * HZ;
  37
  38         __delay(loops >> 32);
  39 }
  40 EXPORT_SYMBOL(__const_udelay);
  41
  42 void __udelay(unsigned long usecs)
  43 {
  44         __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
  45 }
  46 EXPORT_SYMBOL(__udelay);
  47
  48 void __ndelay(unsigned long nsecs)
  49 {
  50         __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
  51 }
  52 EXPORT_SYMBOL(__ndelay);