/*
 * 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/timex.h>
#include <asm/param.h>

extern unsigned long loops_per_jiffy;

static inline void __delay(unsigned long loops)
{
        if (__builtin_constant_p(loops) && loops < 2)
                __asm__ __volatile__ ("nop");
        else if (loops >= 2)
                /* 2 cycles per loop. */
                __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b"
                                : "+r" (loops));
}

/* Undefined function to get compile-time error */
void __bad_udelay(void);
void __bad_ndelay(void);

#define __MAX_UDELAY 30000
#define __MAX_NDELAY 30000

static inline void __udelay(unsigned long usecs)
{
        unsigned long start = get_ccount();
        unsigned long cycles = (usecs * (ccount_freq >> 15)) >> 5;

        /* Note: all variables are unsigned (can wrap around)! */
        while (((unsigned long)get_ccount()) - start < cycles)
                cpu_relax();
}

static inline void udelay(unsigned long usec)
{
        if (__builtin_constant_p(usec) && usec >= __MAX_UDELAY)
                __bad_udelay();
        else
                __udelay(usec);
}

static inline void __ndelay(unsigned long nsec)
{
        /*
         * Inner shift makes sure multiplication doesn't overflow
         * for legitimate nsec values
         */
        unsigned long cycles = (nsec * (ccount_freq >> 15)) >> 15;
        __delay(cycles);
}

#define ndelay(n) ndelay(n)

static inline void ndelay(unsigned long nsec)
{
        if (__builtin_constant_p(nsec) && nsec >= __MAX_NDELAY)
                __bad_ndelay();
        else
                __ndelay(nsec);
}

#endif