[thirdparty/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_

#include <linux/errno.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
e2e69291 MK	9	#include <linux/errno.h>
e2e69291 MK	10
7f84fc67 BG	11	/**
	12	* Implement a hwspinlock uclass.
	13	* Hardware spinlocks are used to perform hardware protection of
	14	* critical sections and synchronisation between multiprocessors.
	15	*/
	16
	17	struct udevice;
	18
	19	/**
	20	* struct hwspinlock - A handle to (allowing control of) a single hardware
	21	* spinlock.
	22	*
	23	* @dev: The device which implements the hardware spinlock.
	24	* @id: The hardware spinlock ID within the provider.
	25	*/
	26	struct hwspinlock {
	27	struct udevice *dev;
	28	unsigned long id;
	29	};
	30
	31	#if CONFIG_IS_ENABLED(DM_HWSPINLOCK)
	32
	33	/**
	34	* hwspinlock_get_by_index - Get a hardware spinlock by integer index
	35	*
	36	* This looks up and request a hardware spinlock. The index is relative to the
	37	* client device; each device is assumed to have n hardware spinlock associated
	38	* with it somehow, and this function finds and requests one of them.
	39	*
	40	* @dev: The client device.
	41	* @index: The index of the hardware spinlock to request, within the
	42	* client's list of hardware spinlock.
	43	* @hws: A pointer to a hardware spinlock struct to initialize.
185f812c	44	* Return: 0 if OK, or a negative error code.
7f84fc67 BG	45	*/
	46	int hwspinlock_get_by_index(struct udevice *dev,
	47	int index, struct hwspinlock *hws);
	48
	49	/**
	50	* Lock the hardware spinlock
	51	*
	52	* @hws: A hardware spinlock struct that previously requested by
	53	* hwspinlock_get_by_index
	54	* @timeout: Timeout value in msecs
	55	* @return: 0 if OK, -ETIMEDOUT if timeout, -ve on other errors
	56	*/
	57	int hwspinlock_lock_timeout(struct hwspinlock *hws, unsigned int timeout);
	58
	59	/**
	60	* Unlock the hardware spinlock
	61	*
	62	* @hws: A hardware spinlock struct that previously requested by
	63	* hwspinlock_get_by_index
	64	* @return: 0 if OK, -ve on error
	65	*/
	66	int hwspinlock_unlock(struct hwspinlock *hws);
	67
	68	#else
	69
	70	static inline int hwspinlock_get_by_index(struct udevice *dev,
	71	int index,
	72	struct hwspinlock *hws)
	73	{
	74	return -ENOSYS;
	75	}
	76
	77	static inline int hwspinlock_lock_timeout(struct hwspinlock *hws,
	78	int timeout)
	79	{
	80	return -ENOSYS;
	81	}
	82
	83	static inline int hwspinlock_unlock(struct hwspinlock *hws)
	84	{
	85	return -ENOSYS;
	86	}
	87
	88	#endif /* CONFIG_DM_HWSPINLOCK */
	89
	90	struct ofnode_phandle_args;
	91
	92	/**
	93	* struct hwspinlock_ops - Driver model hwspinlock operations
	94	*
	95	* The uclass interface is implemented by all hwspinlock devices which use
	96	* driver model.
	97	*/
	98	struct hwspinlock_ops {
	99	/**
	100	* of_xlate - Translate a client's device-tree (OF) hardware specifier.
	101	*
	102	* The hardware core calls this function as the first step in
	103	* implementing a client's hwspinlock_get_by_*() call.
	104	*
	105	* @hws: The hardware spinlock struct to hold the translation
	106	* result.
	107	* @args: The hardware spinlock specifier values from device tree.
	108	* @return 0 if OK, or a negative error code.
109	*/
110	int (of_xlate)(struct hwspinlock hws,
111	struct ofnode_phandle_args *args);
112
113	/**
114	* Lock the hardware spinlock
115	*
116	* @dev: hwspinlock Device
117	* @index: index of the lock to be used
118	* @return 0 if OK, -ve on error
119	*/
120	int (lock)(struct udevice dev, int index);
121
122	/**
123	* Unlock the hardware spinlock
124	*
125	* @dev: hwspinlock Device
126	* @index: index of the lock to be unlocked
127	* @return 0 if OK, -ve on error
128	*/
129	int (unlock)(struct udevice dev, int index);
130
131	/**
132	* Relax - optional
133	* Platform-specific relax method, called by hwspinlock core
134	* while spinning on a lock, between two successive call to
135	* lock
136	*
137	* @dev: hwspinlock Device
138	*/
139	void (relax)(struct udevice dev);
140	};
141
142	#endif /* _HWSPINLOCK_H_ */