78 lines
3.1 KiB
C
78 lines
3.1 KiB
C
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/****************************************************************************
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* arch/arm/src/sam34/sam4cm_idle.c
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*
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* Copyright (C) 2016 Masayuki Ishikawa. All rights reserved.
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* Author: Masayuki Ishikawa <masayuki.ishikawa@gmail.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <nuttx/arch.h>
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#include "up_internal.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: up_idle
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*
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* Description:
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* up_idle() is the logic that will be executed when their is no other
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* ready-to-run task. This is processor idle time and will continue until
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* some interrupt occurs to cause a context switch from the idle task.
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*
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* Processing in this state may be processor-specific. e.g., this is where
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* power management operations might be performed.
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*
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****************************************************************************/
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void up_idle(void)
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{
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#if defined(CONFIG_SUPPRESS_INTERRUPTS) || defined(CONFIG_SUPPRESS_TIMER_INTS)
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/* If the system is idle and there are no timer interrupts, then process
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* "fake" timer interrupts. Hopefully, something will wake up.
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*/
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sched_process_timer();
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#else
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/* Sleep until an interrupt occurs to save power */
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asm("WFI");
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#endif
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}
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