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Diff: targets/TARGET_Maxim/TARGET_MAX32625/mxc/mxc_lock.h
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- 150:02e0a0aed4ec
diff -r 156823d33999 -r 02e0a0aed4ec targets/TARGET_Maxim/TARGET_MAX32625/mxc/mxc_lock.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_Maxim/TARGET_MAX32625/mxc/mxc_lock.h Tue Nov 08 17:45:16 2016 +0000 @@ -0,0 +1,100 @@ +/******************************************************************************* + * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES + * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * Except as contained in this notice, the name of Maxim Integrated + * Products, Inc. shall not be used except as stated in the Maxim Integrated + * Products, Inc. Branding Policy. + * + * The mere transfer of this software does not imply any licenses + * of trade secrets, proprietary technology, copyrights, patents, + * trademarks, maskwork rights, or any other form of intellectual + * property whatsoever. Maxim Integrated Products, Inc. retains all + * ownership rights. + * + * $Date: 2016-03-11 11:46:37 -0600 (Fri, 11 Mar 2016) $ + * $Revision: 21839 $ + * + ******************************************************************************/ + +/** + * @file mxc_lock.h + * @brief Used to create exclusion for critical sections. + */ + +#ifndef _MXC_LOCK_H_ +#define _MXC_LOCK_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +/***** Includes *****/ +#include "mxc_config.h" + +/***** Definitions *****/ + +/***** Globals *****/ + +/***** Function Prototypes *****/ + +/** + * @brief Attempts to acquire the lock. + * @param lock Pointer to variable used for the lock. + * @param value Value to be place in the lock. Can not be 0. + * @details This in an interrupt safe function that can be used as a mutex. + The lock variable must remain in scope until the lock is released. + Will not block if another thread has acquired the lock. + * @returns E_NO_ERROR if everything successful, E_BUSY if lock is taken. + */ +__STATIC_INLINE int mxc_get_lock(uint32_t *lock, uint32_t value) +{ + do { + + // Return if the lock is taken by a different thread + if(__LDREXW((volatile unsigned long *)lock) != 0) { + return E_BUSY; + } + + // Attempt to take the lock + } while(__STREXW(value, (volatile unsigned long *)lock) != 0); + + // Do not start any other memory access until memory barrier is complete + __DMB(); + + return E_NO_ERROR; +} + +/** + * @brief Free the given lock. + * @param lock Pointer to variable used for the lock. + */ +__STATIC_INLINE void mxc_free_lock(uint32_t *lock) +{ + // Ensure memory operations complete before releasing lock + __DMB(); + *lock = 0; +} + +#ifdef __cplusplus +} +#endif + +#endif /* _MXC_LOCK_H_ */