rt-thread-official/bsp/maxim/libraries/MAX32660PeriphDriver/Source/mxc_lock.c

86 lines
2.9 KiB
C

/* ****************************************************************************
* 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: 2018-12-18 15:37:22 -0600 (Tue, 18 Dec 2018) $
* $Revision: 40072 $
*
*************************************************************************** */
/* Define to prevent redundant inclusion */
#ifndef _MXC_LOCK_H_
#define _MXC_LOCK_H_
/* **** Includes **** */
#include "mxc_config.h"
#include "mxc_lock.h"
#ifdef __cplusplus
extern "C" {
#endif
#if defined ( __ICCARM__ )
#define MXC_LOCK_CAST unsigned int volatile *
#else
#define MXC_LOCK_CAST volatile unsigned long *
#endif
/* ************************************************************************** */
int mxc_get_lock(uint32_t *lock, uint32_t value)
{
do {
// Return if the lock is taken by a different thread
if(__LDREXW((MXC_LOCK_CAST)lock) != 0) {
return E_BUSY;
}
// Attempt to take the lock
} while(__STREXW(value, (MXC_LOCK_CAST)lock) != 0);
// Do not start any other memory access until memory barrier is complete
__DMB();
return E_NO_ERROR;
}
/* ************************************************************************** */
void mxc_free_lock(uint32_t *lock)
{
// Ensure memory operations complete before releasing lock
__DMB();
*lock = 0;
}
#ifdef __cplusplus
}
#endif
#endif /* _MXC_LOCK_H_ */