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98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
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/**
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******************************************************************************
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* @addtogroup PIOS PIOS Core hardware abstraction layer
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* @{
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* @addtogroup PIOS_IRQ IRQ Setup Functions
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* @brief STM32 Hardware code to enable and disable interrupts
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* @{
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*
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* @file pios_irq.c
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* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
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* Parts by Thorsten Klose (tk@midibox.org) (tk@midibox.org)
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* @brief IRQ Enable/Disable routines
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* @see The GNU Public License (GPL) Version 3
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*
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*****************************************************************************/
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/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "pios.h"
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#ifdef PIOS_INCLUDE_IRQ
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/* Private Function Prototypes */
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/* Local Variables */
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/* The nesting counter ensures, that interrupts won't be enabled so long nested functions disable them */
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static uint32_t nested_ctr;
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/* Stored priority level before IRQ has been disabled (important for co-existence with vPortEnterCritical) */
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static uint32_t prev_primask;
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/**
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* Disables all interrupts (nested)
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* \return < 0 On errors
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*/
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int32_t PIOS_IRQ_Disable(void)
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{
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/* Get current priority if nested level == 0 */
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if (!nested_ctr) {
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__asm volatile (" mrs %0, primask\n" : "=r" (prev_primask)
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);
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}
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/* Disable interrupts */
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__asm volatile (" mov r0, #1 \n" " msr primask, r0\n" ::: "r0");
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++nested_ctr;
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/* No error */
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return 0;
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}
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/**
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* Enables all interrupts (nested)
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* \return < 0 on errors
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* \return -1 on nesting errors (PIOS_IRQ_Disable() hasn't been called before)
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*/
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int32_t PIOS_IRQ_Enable(void)
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{
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/* Check for nesting error */
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if (nested_ctr == 0) {
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/* Nesting error */
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return -1;
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}
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/* Decrease nesting level */
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--nested_ctr;
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/* Set back previous priority once nested level reached 0 again */
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if (nested_ctr == 0) {
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__asm volatile (" msr primask, %0\n" ::"r" (prev_primask)
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);
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}
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/* No error */
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return 0;
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}
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#endif /* PIOS_INCLUDE_IRQ */
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/**
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* @}
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* @}
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*/
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