/drivers/hwspinlock/hwspinlock_internal.h

 1/*
 2 * Hardware spinlocks internal header
 3 *
 4 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
 5 *
 6 * Contact: Ohad Ben-Cohen <ohad@wizery.com>
 7 *
 8 * This program is free software; you can redistribute it and/or modify it
 9 * under the terms of the GNU General Public License version 2 as published
10 * by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17
18#ifndef __HWSPINLOCK_HWSPINLOCK_H
19#define __HWSPINLOCK_HWSPINLOCK_H
20
21#include <linux/spinlock.h>
22#include <linux/device.h>
23
24/**
25 * struct hwspinlock_ops - platform-specific hwspinlock handlers
26 *
27 * @trylock: make a single attempt to take the lock. returns 0 on
28 *	     failure and true on success. may _not_ sleep.
29 * @unlock:  release the lock. always succeed. may _not_ sleep.
30 * @relax:   optional, platform-specific relax handler, called by hwspinlock
31 *	     core while spinning on a lock, between two successive
32 *	     invocations of @trylock. may _not_ sleep.
33 */
34struct hwspinlock_ops {
35	int (*trylock)(struct hwspinlock *lock);
36	void (*unlock)(struct hwspinlock *lock);
37	void (*relax)(struct hwspinlock *lock);
38};
39
40/**
41 * struct hwspinlock - this struct represents a single hwspinlock instance
42 *
43 * @dev: underlying device, will be used to invoke runtime PM api
44 * @ops: platform-specific hwspinlock handlers
45 * @id: a global, unique, system-wide, index of the lock.
46 * @lock: initialized and used by hwspinlock core
47 * @owner: underlying implementation module, used to maintain module ref count
48 *
49 * Note: currently simplicity was opted for, but later we can squeeze some
50 * memory bytes by grouping the dev, ops and owner members in a single
51 * per-platform struct, and have all hwspinlocks point at it.
52 */
53struct hwspinlock {
54	struct device *dev;
55	const struct hwspinlock_ops *ops;
56	int id;
57	spinlock_t lock;
58	struct module *owner;
59};
60
61#endif /* __HWSPINLOCK_HWSPINLOCK_H */