diff options
author | Benjamin Gaignard <benjamin.gaignard@linaro.org> | 2018-11-27 13:49:50 +0100 |
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committer | Tom Rini <trini@konsulko.com> | 2018-12-06 23:26:32 -0500 |
commit | 7f84fc670b17fca3d8d1b7c9472a19bb8085c890 (patch) | |
tree | 5af913847507ee1d58408c5f053bcdb2731b0133 /include/hwspinlock.h | |
parent | 3b074fb22b8f09178200b969395fa9f3d97a67e6 (diff) |
dm: Add Hardware Spinlock class
This is uclass for Hardware Spinlocks.
It implements two mandatory operations: lock and unlock
and one optional relax operation.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Diffstat (limited to 'include/hwspinlock.h')
-rw-r--r-- | include/hwspinlock.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/include/hwspinlock.h b/include/hwspinlock.h new file mode 100644 index 0000000000..99389c13c2 --- /dev/null +++ b/include/hwspinlock.h @@ -0,0 +1,140 @@ +/* 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_ */ |