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  */
  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 */