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  */
34 struct 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  */
53 struct 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 */
62