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 struct hwspinlock_device;
25 
26 /**
27  * struct hwspinlock_ops - platform-specific hwspinlock handlers
28  *
29  * @trylock: make a single attempt to take the lock. returns 0 on
30  *	     failure and true on success. may _not_ sleep.
31  * @unlock:  release the lock. always succeed. may _not_ sleep.
32  * @relax:   optional, platform-specific relax handler, called by hwspinlock
33  *	     core while spinning on a lock, between two successive
34  *	     invocations of @trylock. may _not_ sleep.
35  */
36 struct hwspinlock_ops {
37 	int (*trylock)(struct hwspinlock *lock);
38 	void (*unlock)(struct hwspinlock *lock);
39 	void (*relax)(struct hwspinlock *lock);
40 };
41 
42 /**
43  * struct hwspinlock - this struct represents a single hwspinlock instance
44  * @bank: the hwspinlock_device structure which owns this lock
45  * @lock: initialized and used by hwspinlock core
46  * @priv: private data, owned by the underlying platform-specific hwspinlock drv
47  */
48 struct hwspinlock {
49 	struct hwspinlock_device *bank;
50 	spinlock_t lock;
51 	void *priv;
52 };
53 
54 /**
55  * struct hwspinlock_device - a device which usually spans numerous hwspinlocks
56  * @dev: underlying device, will be used to invoke runtime PM api
57  * @ops: platform-specific hwspinlock handlers
58  * @base_id: id index of the first lock in this device
59  * @num_locks: number of locks in this device
60  * @lock: dynamically allocated array of 'struct hwspinlock'
61  */
62 struct hwspinlock_device {
63 	struct device *dev;
64 	const struct hwspinlock_ops *ops;
65 	int base_id;
66 	int num_locks;
67 	struct hwspinlock lock[0];
68 };
69 
70 static inline int hwlock_to_id(struct hwspinlock *hwlock)
71 {
72 	int local_id = hwlock - &hwlock->bank->lock[0];
73 
74 	return hwlock->bank->base_id + local_id;
75 }
76 
77 #endif /* __HWSPINLOCK_HWSPINLOCK_H */
78