[deliverable/linux.git] / arch / xtensa / include / asm / delay.h

/*
 * 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
Commit	Line	Data
	1	/*
	2	* include/asm-xtensa/delay.h
	3	*
	4	* This file is subject to the terms and conditions of the GNU General Public
	5	* License. See the file "COPYING" in the main directory of this archive
	6	* for more details.
	7	*
	8	* Copyright (C) 2001 - 2005 Tensilica Inc.
	9	*
	10	*/
	11
	12	#ifndef _XTENSA_DELAY_H
	13	#define _XTENSA_DELAY_H
	14
	15	#include <asm/timex.h>
	16	#include <asm/param.h>
	17
	18	extern unsigned long loops_per_jiffy;
	19
	20	static inline void __delay(unsigned long loops)
	21	{
	22	if (__builtin_constant_p(loops) && loops < 2)
	23	__asm__ __volatile__ ("nop");
	24	else if (loops >= 2)
	25	/* 2 cycles per loop. */
	26	__asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b"
	27	: "+r" (loops));
	28	}
	29
	30	/* Undefined function to get compile-time error */
	31	void __bad_udelay(void);
	32	void __bad_ndelay(void);
	33
	34	#define __MAX_UDELAY 30000
	35	#define __MAX_NDELAY 30000
	36
	37	static inline void __udelay(unsigned long usecs)
	38	{
	39	unsigned long start = get_ccount();
	40	unsigned long cycles = (usecs * (ccount_freq >> 15)) >> 5;
	41
	42	/* Note: all variables are unsigned (can wrap around)! */
	43	while (((unsigned long)get_ccount()) - start < cycles)
	44	cpu_relax();
	45	}
	46
	47	static inline void udelay(unsigned long usec)
	48	{
	49	if (__builtin_constant_p(usec) && usec >= __MAX_UDELAY)
	50	__bad_udelay();
	51	else
	52	__udelay(usec);
	53	}
	54
	55	static inline void __ndelay(unsigned long nsec)
	56	{
	57	/*
	58	* Inner shift makes sure multiplication doesn't overflow
	59	* for legitimate nsec values
	60	*/
	61	unsigned long cycles = (nsec * (ccount_freq >> 15)) >> 15;
	62	__delay(cycles);
	63	}
	64
	65	#define ndelay(n) ndelay(n)
	66
	67	static inline void ndelay(unsigned long nsec)
	68	{
	69	if (__builtin_constant_p(nsec) && nsec >= __MAX_NDELAY)
	70	__bad_ndelay();
	71	else
	72	__ndelay(nsec);
	73	}
	74
	75	#endif