Diff: TARGET_MAX32625NEXPAQ/TOOLCHAIN_IAR/mxc_lock.h

Revision:

171:3a7713b1edbc

Parent:

169:a7c7b631e539

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TARGET_MAX32625NEXPAQ/TOOLCHAIN_IAR/mxc_lock.h	Thu Nov 08 11:45:42 2018 +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 uint32_t *)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_ */