[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / include / asm / delay.h

#ifndef _ASM_POWERPC_DELAY_H
#define _ASM_POWERPC_DELAY_H
#ifdef __KERNEL__

#include <asm/time.h>

/*
 * Copyright 1996, Paul Mackerras.
 * Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
 * Anton Blanchard.
 */

extern void __delay(unsigned long loops);
extern void udelay(unsigned long usecs);

/*
 * On shared processor machines the generic implementation of mdelay can
 * result in large errors. While each iteration of the loop inside mdelay
 * is supposed to take 1ms, the hypervisor could sleep our partition for
 * longer (eg 10ms). With the right timing these errors can add up.
 *
 * Since there is no 32bit overflow issue on 64bit kernels, just call
 * udelay directly.
 */
#ifdef CONFIG_PPC64
#define mdelay(n)	udelay((n) * 1000)
#endif

/**
 * spin_event_timeout - spin until a condition gets true or a timeout elapses
 * @condition: a C expression to evalate
 * @timeout: timeout, in microseconds
 * @delay: the number of microseconds to delay between each evaluation of
 *         @condition
 *
 * The process spins until the condition evaluates to true (non-zero) or the
 * timeout elapses.  The return value of this macro is the value of
 * @condition when the loop terminates. This allows you to determine the cause
 * of the loop terminates.  If the return value is zero, then you know a
 * timeout has occurred.
 *
 * This primary purpose of this macro is to poll on a hardware register
 * until a status bit changes.  The timeout ensures that the loop still
 * terminates even if the bit never changes.  The delay is for devices that
 * need a delay in between successive reads.
 *
 * gcc will optimize out the if-statement if @delay is a constant.
 */
#define spin_event_timeout(condition, timeout, delay)                          \
({                                                                             \
	typeof(condition) __ret;                                               \
	unsigned long __loops = tb_ticks_per_usec * timeout;                   \
	unsigned long __start = get_tbl();                                     \
	while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \
		if (delay)                                                     \
			udelay(delay);                                         \
		else                                                           \
			cpu_relax();                                           \
	if (!__ret)                                                            \
		__ret = (condition);                                           \
	__ret;		                                                       \
})

#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_DELAY_H */
Commit	Line	Data
c55377ee PM	1	#ifndef _ASM_POWERPC_DELAY_H
c55377ee PM	2	#define _ASM_POWERPC_DELAY_H
88ced031	3	#ifdef __KERNEL__
1da177e4	4
9317726d TT	5	#include <asm/time.h>
9317726d TT	6
1da177e4 LT	7	/*
1da177e4 LT	8	* Copyright 1996, Paul Mackerras.
9317726d	9	* Copyright (C) 2009 Freescale Semiconductor, Inc. All rights reserved.
1da177e4 LT	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the License, or (at your option) any later version.
	15	*
	16	* PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
	17	* Anton Blanchard.
	18	*/
	19
6defa38b PM	20	extern void __delay(unsigned long loops);
6defa38b PM	21	extern void udelay(unsigned long usecs);
1da177e4	22
1e92a550 AB	23	/*
	24	* On shared processor machines the generic implementation of mdelay can
	25	* result in large errors. While each iteration of the loop inside mdelay
	26	* is supposed to take 1ms, the hypervisor could sleep our partition for
	27	* longer (eg 10ms). With the right timing these errors can add up.
	28	*
	29	* Since there is no 32bit overflow issue on 64bit kernels, just call
	30	* udelay directly.
	31	*/
	32	#ifdef CONFIG_PPC64
	33	#define mdelay(n) udelay((n) * 1000)
	34	#endif
	35
9317726d TT	36	/**
	37	* spin_event_timeout - spin until a condition gets true or a timeout elapses
	38	* @condition: a C expression to evalate
	39	* @timeout: timeout, in microseconds
	40	* @delay: the number of microseconds to delay between each evaluation of
	41	* @condition
	42	*
	43	* The process spins until the condition evaluates to true (non-zero) or the
	44	* timeout elapses. The return value of this macro is the value of
	45	* @condition when the loop terminates. This allows you to determine the cause
	46	* of the loop terminates. If the return value is zero, then you know a
	47	* timeout has occurred.
	48	*
	49	* This primary purpose of this macro is to poll on a hardware register
	50	* until a status bit changes. The timeout ensures that the loop still
	51	* terminates even if the bit never changes. The delay is for devices that
	52	* need a delay in between successive reads.
	53	*
	54	* gcc will optimize out the if-statement if @delay is a constant.
	55	*/
	56	#define spin_event_timeout(condition, timeout, delay) \
	57	({ \
	58	typeof(condition) __ret; \
	59	unsigned long __loops = tb_ticks_per_usec * timeout; \
	60	unsigned long __start = get_tbl(); \
	61	while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \
	62	if (delay) \
	63	udelay(delay); \
	64	else \
	65	cpu_relax(); \
ad9064d5 GL	66	if (!__ret) \
ad9064d5 GL	67	__ret = (condition); \
9317726d TT	68	__ret; \
	69	})
	70
88ced031	71	#endif /* __KERNEL__ */
c55377ee	72	#endif /* _ASM_POWERPC_DELAY_H */