141 lines
3.5 KiB
C
141 lines
3.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
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/*
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* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
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*/
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#ifndef _HWSPINLOCK_H_
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#define _HWSPINLOCK_H_
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/**
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* Implement a hwspinlock uclass.
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* Hardware spinlocks are used to perform hardware protection of
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* critical sections and synchronisation between multiprocessors.
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*/
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struct udevice;
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/**
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* struct hwspinlock - A handle to (allowing control of) a single hardware
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* spinlock.
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*
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* @dev: The device which implements the hardware spinlock.
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* @id: The hardware spinlock ID within the provider.
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*/
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struct hwspinlock {
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struct udevice *dev;
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unsigned long id;
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};
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#if CONFIG_IS_ENABLED(DM_HWSPINLOCK)
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/**
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* hwspinlock_get_by_index - Get a hardware spinlock by integer index
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*
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* This looks up and request a hardware spinlock. The index is relative to the
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* client device; each device is assumed to have n hardware spinlock associated
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* with it somehow, and this function finds and requests one of them.
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*
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* @dev: The client device.
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* @index: The index of the hardware spinlock to request, within the
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* client's list of hardware spinlock.
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* @hws: A pointer to a hardware spinlock struct to initialize.
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* @return 0 if OK, or a negative error code.
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*/
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int hwspinlock_get_by_index(struct udevice *dev,
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int index, struct hwspinlock *hws);
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/**
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* Lock the hardware spinlock
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*
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* @hws: A hardware spinlock struct that previously requested by
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* hwspinlock_get_by_index
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* @timeout: Timeout value in msecs
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* @return: 0 if OK, -ETIMEDOUT if timeout, -ve on other errors
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*/
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int hwspinlock_lock_timeout(struct hwspinlock *hws, unsigned int timeout);
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/**
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* Unlock the hardware spinlock
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*
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* @hws: A hardware spinlock struct that previously requested by
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* hwspinlock_get_by_index
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* @return: 0 if OK, -ve on error
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*/
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int hwspinlock_unlock(struct hwspinlock *hws);
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#else
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static inline int hwspinlock_get_by_index(struct udevice *dev,
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int index,
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struct hwspinlock *hws)
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{
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return -ENOSYS;
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}
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static inline int hwspinlock_lock_timeout(struct hwspinlock *hws,
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int timeout)
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{
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return -ENOSYS;
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}
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static inline int hwspinlock_unlock(struct hwspinlock *hws)
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{
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return -ENOSYS;
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}
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#endif /* CONFIG_DM_HWSPINLOCK */
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struct ofnode_phandle_args;
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/**
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* struct hwspinlock_ops - Driver model hwspinlock operations
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*
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* The uclass interface is implemented by all hwspinlock devices which use
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* driver model.
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*/
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struct hwspinlock_ops {
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/**
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* of_xlate - Translate a client's device-tree (OF) hardware specifier.
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*
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* The hardware core calls this function as the first step in
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* implementing a client's hwspinlock_get_by_*() call.
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*
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* @hws: The hardware spinlock struct to hold the translation
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* result.
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* @args: The hardware spinlock specifier values from device tree.
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* @return 0 if OK, or a negative error code.
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*/
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int (*of_xlate)(struct hwspinlock *hws,
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struct ofnode_phandle_args *args);
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/**
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* Lock the hardware spinlock
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*
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* @dev: hwspinlock Device
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* @index: index of the lock to be used
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* @return 0 if OK, -ve on error
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*/
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int (*lock)(struct udevice *dev, int index);
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/**
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* Unlock the hardware spinlock
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*
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* @dev: hwspinlock Device
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* @index: index of the lock to be unlocked
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* @return 0 if OK, -ve on error
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*/
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int (*unlock)(struct udevice *dev, int index);
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/**
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* Relax - optional
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* Platform-specific relax method, called by hwspinlock core
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* while spinning on a lock, between two successive call to
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* lock
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*
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* @dev: hwspinlock Device
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*/
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void (*relax)(struct udevice *dev);
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};
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#endif /* _HWSPINLOCK_H_ */
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