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 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 */