63 lines
1.3 KiB
C
63 lines
1.3 KiB
C
/*
|
|
* delay.h - delay functions
|
|
*
|
|
* Copyright (c) 2004-2007 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#ifndef __ASM_DELAY_H__
|
|
#define __ASM_DELAY_H__
|
|
|
|
#include <mach/anomaly.h>
|
|
|
|
static inline void __delay(unsigned long loops)
|
|
{
|
|
if (ANOMALY_05000312) {
|
|
/* Interrupted loads to loop registers -> bad */
|
|
unsigned long tmp;
|
|
__asm__ __volatile__(
|
|
"[--SP] = LC0;"
|
|
"[--SP] = LT0;"
|
|
"[--SP] = LB0;"
|
|
"LSETUP (1f,1f) LC0 = %1;"
|
|
"1: NOP;"
|
|
/* We take advantage of the fact that LC0 is 0 at
|
|
* the end of the loop. Otherwise we'd need some
|
|
* NOPs after the CLI here.
|
|
*/
|
|
"CLI %0;"
|
|
"LB0 = [SP++];"
|
|
"LT0 = [SP++];"
|
|
"LC0 = [SP++];"
|
|
"STI %0;"
|
|
: "=d" (tmp)
|
|
: "a" (loops)
|
|
);
|
|
} else
|
|
__asm__ __volatile__ (
|
|
"LSETUP(1f, 1f) LC0 = %0;"
|
|
"1: NOP;"
|
|
:
|
|
: "a" (loops)
|
|
: "LT0", "LB0", "LC0"
|
|
);
|
|
}
|
|
|
|
#include <linux/param.h> /* needed for HZ */
|
|
|
|
/*
|
|
* Use only for very small delays ( < 1 msec). Should probably use a
|
|
* lookup table, really, as the multiplications take much too long with
|
|
* short delays. This is a "reasonable" implementation, though (and the
|
|
* first constant multiplications gets optimized away if the delay is
|
|
* a constant)
|
|
*/
|
|
static inline void udelay(unsigned long usecs)
|
|
{
|
|
extern unsigned long loops_per_jiffy;
|
|
__delay(usecs * loops_per_jiffy / (1000000 / HZ));
|
|
}
|
|
|
|
#endif
|