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Diffstat (limited to 'nuttx/arch/arm/src/common/up_idle.c')
-rw-r--r-- | nuttx/arch/arm/src/common/up_idle.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/common/up_idle.c b/nuttx/arch/arm/src/common/up_idle.c new file mode 100644 index 000000000..62557c3a8 --- /dev/null +++ b/nuttx/arch/arm/src/common/up_idle.c @@ -0,0 +1,91 @@ +/**************************************************************************** + * arch/arm/src/common/up_idle.c + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <nuttx/arch.h> +#include "up_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_idle + * + * Description: + * up_idle() is the logic that will be executed when their is no other + * ready-to-run task. This is processor idle time and will continue until + * some interrupt occurs to cause a context switch from the idle task. + * + * Processing in this state may be processor-specific. e.g., this is where + * power management operations might be performed. + * + ****************************************************************************/ + +void up_idle(void) +{ +#if defined(CONFIG_SUPPRESS_INTERRUPTS) || defined(CONFIG_SUPPRESS_TIMER_INTS) + /* If the system is idle and there are no timer interrupts, then process + * "fake" timer interrupts. Hopefully, something will wake up. + */ + + sched_process_timer(); +#else + + /* Sleep until an interrupt occurs to save power */ + +#if 0 + asm("WFI"); /* For example */ +#endif +#endif +} + |