Viewing file:  delay.h (1.14 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* include/asm-xtensa/delay.h
*
* 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) 2001 - 2005 Tensilica Inc.
*
*/
#ifndef _XTENSA_DELAY_H
#define _XTENSA_DELAY_H
#include <asm/processor.h>
#include <asm/param.h>
extern unsigned long loops_per_jiffy;
static inline void __delay(unsigned long loops)
{
/* 2 cycles per loop. */
__asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b"
: "=r" (loops) : "0" (loops));
}
static __inline__ u32 xtensa_get_ccount(void)
{
u32 ccount;
asm volatile ("rsr %0, 234; # CCOUNT\n" : "=r" (ccount));
return ccount;
}
/* For SMP/NUMA systems, change boot_cpu_data to something like
* local_cpu_data->... where local_cpu_data points to the current
* cpu. */
static __inline__ void udelay (unsigned long usecs)
{
unsigned long start = xtensa_get_ccount();
unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ));
/* Note: all variables are unsigned (can wrap around)! */
while (((unsigned long)xtensa_get_ccount()) - start < cycles)
;
}
#endif
|