/drivers/staging/tidspbridge/include/dspbridge/sync.h

  1/*
  2 * sync.h
  3 *
  4 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
  5 *
  6 * Provide synchronization services.
  7 *
  8 * Copyright (C) 2005-2006 Texas Instruments, Inc.
  9 *
 10 * This package is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License version 2 as
 12 * published by the Free Software Foundation.
 13 *
 14 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 16 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 17 */
 18
 19#ifndef _SYNC_H
 20#define _SYNC_H
 21
 22#include <dspbridge/dbdefs.h>
 23#include <dspbridge/host_os.h>
 24
 25
 26/* Special timeout value indicating an infinite wait: */
 27#define SYNC_INFINITE  0xffffffff
 28
 29/**
 30 * struct sync_object - the basic sync_object structure
 31 * @comp:	use to signal events
 32 * @multi_comp:	use to signal multiple events.
 33 *
 34 */
 35struct sync_object{
 36	struct completion comp;
 37	struct completion *multi_comp;
 38};
 39
 40/**
 41 * sync_init_event() - set initial state for a sync_event element
 42 * @event:	event to be initialized.
 43 *
 44 * Set the initial state for a sync_event element.
 45 */
 46
 47static inline void sync_init_event(struct sync_object *event)
 48{
 49	init_completion(&event->comp);
 50	event->multi_comp = NULL;
 51}
 52
 53/**
 54 * sync_reset_event() - reset a sync_event element
 55 * @event:	event to be reset.
 56 *
 57 * This function reset to the initial state to @event.
 58 */
 59
 60static inline void sync_reset_event(struct sync_object *event)
 61{
 62	INIT_COMPLETION(event->comp);
 63	event->multi_comp = NULL;
 64}
 65
 66/**
 67 * sync_set_event() - set or signal and specified event
 68 * @event:	Event to be set..
 69 *
 70 * set the @event, if there is an thread waiting for the event
 71 * it will be waken up, this function only wakes one thread.
 72 */
 73
 74void sync_set_event(struct sync_object *event);
 75
 76/**
 77 * sync_wait_on_event() - waits for a event to be set.
 78 * @event:	events to wait for it.
 79 * @timeout	timeout on waiting for the evetn.
 80 *
 81 * This functios will wait until @event is set or until timeout. In case of
 82 * success the function will return 0 and
 83 * in case of timeout the function will return -ETIME
 84 * in case of signal the function will return -ERESTARTSYS
 85 */
 86
 87static inline int sync_wait_on_event(struct sync_object *event,
 88							unsigned timeout)
 89{
 90	int res;
 91
 92	res = wait_for_completion_interruptible_timeout(&event->comp,
 93						msecs_to_jiffies(timeout));
 94	if (!res)
 95		res = -ETIME;
 96	else if (res > 0)
 97		res = 0;
 98
 99	return res;
100}
101
102/**
103 * sync_wait_on_multiple_events() - waits for multiple events to be set.
104 * @events:	Array of events to wait for them.
105 * @count:	number of elements of the array.
106 * @timeout	timeout on waiting for the evetns.
107 * @pu_index	index of the event set.
108 *
109 * This functios will wait until any of the array element is set or until
110 * timeout. In case of success the function will return 0 and
111 * @pu_index will store the index of the array element set and in case
112 * of timeout the function will return -ETIME.
113 */
114
115int sync_wait_on_multiple_events(struct sync_object **events,
116				     unsigned count, unsigned timeout,
117				     unsigned *index);
118
119#endif /* _SYNC_H */