74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
/**
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* @file meslock.h
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*
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* @brief Provides the subdevice lock class.
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* @note Copyright (C) 2006 Meilhaus Electronic GmbH (support@meilhaus.de)
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* @author Guenter Gebhardt
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*/
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#ifndef _MESLOCK_H_
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#define _MESLOCK_H_
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#include <linux/spinlock.h>
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#ifdef __KERNEL__
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/**
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* @brief The subdevice lock class.
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*/
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typedef struct me_slock {
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struct file *filep; /**< Pointer to file structure holding the subdevice. */
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int count; /**< Number of tasks which are inside the subdevice. */
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spinlock_t spin_lock; /**< Spin lock protecting the attributes from concurrent access. */
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} me_slock_t;
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/**
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* @brief Tries to enter a subdevice.
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*
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* @param slock The subdevice lock instance.
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* @param filep The file structure identifying the calling process.
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*
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* @return 0 on success.
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*/
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int me_slock_enter(struct me_slock *slock, struct file *filep);
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/**
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* @brief Exits a subdevice.
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*
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* @param slock The subdevice lock instance.
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* @param filep The file structure identifying the calling process.
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*
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* @return 0 on success.
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*/
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int me_slock_exit(struct me_slock *slock, struct file *filep);
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/**
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* @brief Tries to perform a locking action on a subdevice.
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*
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* @param slock The subdevice lock instance.
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* @param filep The file structure identifying the calling process.
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* @param The action to be done.
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*
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* @return 0 on success.
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*/
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int me_slock_lock(struct me_slock *slock, struct file *filep, int lock);
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/**
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* @brief Initializes a lock structure.
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*
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* @param slock The lock structure to initialize.
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* @return 0 on success.
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*/
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int me_slock_init(me_slock_t * slock);
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/**
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* @brief Deinitializes a lock structure.
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*
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* @param slock The lock structure to deinitialize.
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* @return 0 on success.
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*/
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void me_slock_deinit(me_slock_t * slock);
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#endif
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#endif
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