[J-u-boot.git] / include / hwspinlock.h

/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
/*
 * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
 */

#ifndef _HWSPINLOCK_H_
#define _HWSPINLOCK_H_

/**
 * Implement a hwspinlock uclass.
 * Hardware spinlocks are used to perform hardware protection of
 * critical sections and synchronisation between multiprocessors.
 */

struct udevice;

/**
 * struct hwspinlock - A handle to (allowing control of) a single hardware
 * spinlock.
 *
 * @dev: The device which implements the hardware spinlock.
 * @id: The hardware spinlock ID within the provider.
 */
struct hwspinlock {
	struct udevice *dev;
	unsigned long id;
};

#if CONFIG_IS_ENABLED(DM_HWSPINLOCK)

/**
 * hwspinlock_get_by_index - Get a hardware spinlock by integer index
 *
 * This looks up and request a hardware spinlock. The index is relative to the
 * client device; each device is assumed to have n hardware spinlock associated
 * with it somehow, and this function finds and requests one of them.
 *
 * @dev:	The client device.
 * @index:	The index of the hardware spinlock to request, within the
 *		client's list of hardware spinlock.
 * @hws:	A pointer to a hardware spinlock struct to initialize.
 * @return 0 if OK, or a negative error code.
 */
int hwspinlock_get_by_index(struct udevice *dev,
			    int index, struct hwspinlock *hws);

/**
 * Lock the hardware spinlock
 *
 * @hws:	A hardware spinlock struct that previously requested by
 *		hwspinlock_get_by_index
 * @timeout:	Timeout value in msecs
 * @return: 0 if OK, -ETIMEDOUT if timeout, -ve on other errors
 */
int hwspinlock_lock_timeout(struct hwspinlock *hws, unsigned int timeout);

/**
 * Unlock the hardware spinlock
 *
 * @hws:	A hardware spinlock struct that previously requested by
 *		hwspinlock_get_by_index
 * @return: 0 if OK, -ve on error
 */
int hwspinlock_unlock(struct hwspinlock *hws);

#else

static inline int hwspinlock_get_by_index(struct udevice *dev,
					  int index,
					  struct hwspinlock *hws)
{
	return -ENOSYS;
}

static inline int hwspinlock_lock_timeout(struct hwspinlock *hws,
					  int timeout)
{
	return -ENOSYS;
}

static inline int hwspinlock_unlock(struct hwspinlock *hws)
{
	return -ENOSYS;
}

#endif /* CONFIG_DM_HWSPINLOCK */

struct ofnode_phandle_args;

/**
 * struct hwspinlock_ops - Driver model hwspinlock operations
 *
 * The uclass interface is implemented by all hwspinlock devices which use
 * driver model.
 */
struct hwspinlock_ops {
	/**
	 * of_xlate - Translate a client's device-tree (OF) hardware specifier.
	 *
	 * The hardware core calls this function as the first step in
	 * implementing a client's hwspinlock_get_by_*() call.
	 *
	 * @hws:	The hardware spinlock struct to hold the translation
	 *			result.
	 * @args:	The hardware spinlock specifier values from device tree.
	 * @return 0 if OK, or a negative error code.
	 */
	int (*of_xlate)(struct hwspinlock *hws,
			struct ofnode_phandle_args *args);

	/**
	 * Lock the hardware spinlock
	 *
	 * @dev:	hwspinlock Device
	 * @index:	index of the lock to be used
	 * @return 0 if OK, -ve on error
	 */
	int (*lock)(struct udevice *dev, int index);

	/**
	 * Unlock the hardware spinlock
	 *
	 * @dev:	hwspinlock Device
	 * @index:	index of the lock to be unlocked
	 * @return 0 if OK, -ve on error
	 */
	int (*unlock)(struct udevice *dev, int index);

	/**
	 * Relax - optional
	 *       Platform-specific relax method, called by hwspinlock core
	 *       while spinning on a lock, between two successive call to
	 *       lock
	 *
	 * @dev:	hwspinlock Device
	 */
	void (*relax)(struct udevice *dev);
};

#endif /* _HWSPINLOCK_H_ */
Commit	Line	Data
7f84fc67 BG	1	/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
	2	/*
	3	* Copyright (C) 2018, STMicroelectronics - All Rights Reserved
	4	*/
	5
	6	#ifndef _HWSPINLOCK_H_
	7	#define _HWSPINLOCK_H_
	8
	9	/**
	10	* Implement a hwspinlock uclass.
	11	* Hardware spinlocks are used to perform hardware protection of
	12	* critical sections and synchronisation between multiprocessors.
	13	*/
	14
	15	struct udevice;
	16
	17	/**
	18	* struct hwspinlock - A handle to (allowing control of) a single hardware
	19	* spinlock.
	20	*
	21	* @dev: The device which implements the hardware spinlock.
	22	* @id: The hardware spinlock ID within the provider.
	23	*/
	24	struct hwspinlock {
	25	struct udevice *dev;
	26	unsigned long id;
	27	};
	28
	29	#if CONFIG_IS_ENABLED(DM_HWSPINLOCK)
	30
	31	/**
	32	* hwspinlock_get_by_index - Get a hardware spinlock by integer index
	33	*
	34	* This looks up and request a hardware spinlock. The index is relative to the
	35	* client device; each device is assumed to have n hardware spinlock associated
	36	* with it somehow, and this function finds and requests one of them.
	37	*
	38	* @dev: The client device.
	39	* @index: The index of the hardware spinlock to request, within the
	40	* client's list of hardware spinlock.
	41	* @hws: A pointer to a hardware spinlock struct to initialize.
	42	* @return 0 if OK, or a negative error code.
	43	*/
	44	int hwspinlock_get_by_index(struct udevice *dev,
	45	int index, struct hwspinlock *hws);
	46
	47	/**
	48	* Lock the hardware spinlock
	49	*
	50	* @hws: A hardware spinlock struct that previously requested by
	51	* hwspinlock_get_by_index
	52	* @timeout: Timeout value in msecs
	53	* @return: 0 if OK, -ETIMEDOUT if timeout, -ve on other errors
	54	*/
	55	int hwspinlock_lock_timeout(struct hwspinlock *hws, unsigned int timeout);
	56
	57	/**
	58	* Unlock the hardware spinlock
	59	*
	60	* @hws: A hardware spinlock struct that previously requested by
	61	* hwspinlock_get_by_index
	62	* @return: 0 if OK, -ve on error
	63	*/
	64	int hwspinlock_unlock(struct hwspinlock *hws);
65
66	#else
67
68	static inline int hwspinlock_get_by_index(struct udevice *dev,
69	int index,
70	struct hwspinlock *hws)
71	{
72	return -ENOSYS;
73	}
74
75	static inline int hwspinlock_lock_timeout(struct hwspinlock *hws,
76	int timeout)
77	{
78	return -ENOSYS;
79	}
80
81	static inline int hwspinlock_unlock(struct hwspinlock *hws)
82	{
83	return -ENOSYS;
84	}
85
86	#endif /* CONFIG_DM_HWSPINLOCK */
87
88	struct ofnode_phandle_args;
89
90	/**
91	* struct hwspinlock_ops - Driver model hwspinlock operations
92	*
93	* The uclass interface is implemented by all hwspinlock devices which use
94	* driver model.
95	*/
96	struct hwspinlock_ops {
97	/**
98	* of_xlate - Translate a client's device-tree (OF) hardware specifier.
99	*
100	* The hardware core calls this function as the first step in
101	* implementing a client's hwspinlock_get_by_*() call.
102	*
103	* @hws: The hardware spinlock struct to hold the translation
104	* result.
105	* @args: The hardware spinlock specifier values from device tree.
106	* @return 0 if OK, or a negative error code.
107	*/
108	int (of_xlate)(struct hwspinlock hws,
109	struct ofnode_phandle_args *args);
110
111	/**
112	* Lock the hardware spinlock
113	*
114	* @dev: hwspinlock Device
115	* @index: index of the lock to be used
116	* @return 0 if OK, -ve on error
117	*/
118	int (lock)(struct udevice dev, int index);
119
120	/**
121	* Unlock the hardware spinlock
122	*
123	* @dev: hwspinlock Device
124	* @index: index of the lock to be unlocked
125	* @return 0 if OK, -ve on error
126	*/
127	int (unlock)(struct udevice dev, int index);
128
129	/**
130	* Relax - optional
131	* Platform-specific relax method, called by hwspinlock core
132	* while spinning on a lock, between two successive call to
133	* lock
134	*
135	* @dev: hwspinlock Device
136	*/
137	void (relax)(struct udevice dev);
138	};
139
140	#endif /* _HWSPINLOCK_H_ */