irq_arch.h

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/*
 * Copyright (C) 2014 Freie Universität Berlin
 *               2020 Otto-von-Guericke-Universität Magdeburg
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#ifndef IRQ_ARCH_H
#define IRQ_ARCH_H
 
#include <stdbool.h>
#include <msp430.h>
#include "irq.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
/*
 * gcc warns for missing NOPs before/after interrupt enable/disable.
 * so I added the NOP instructions, even though they might not be necessary
 * due to following AND. // Kaspar
 */
 
extern volatile int __irq_is_in;
#define _GENERAL_INTERRUPT_ENABLE   (0x0008)
 
__attribute__((always_inline)) static inline unsigned int irq_disable(void)
{
    unsigned int state;
    __asm__ volatile(
        "mov.w SR, %[state]"                "\n\t"
        "bic %[gie], SR"                    "\n\t"
        "nop"                               "\n\t"
        "and %[gie], %[state]"              "\n\t"
        : [state]   "=r"(state)
        : [gie]     "i"(_GENERAL_INTERRUPT_ENABLE)
        : "memory"
    );
 
    return state;
}
 
__attribute__((always_inline)) static inline unsigned int irq_enable(void)
{
    unsigned int state;
    __asm__ volatile(
        "mov.w SR, %[state]"                "\n\t"
        "nop"                               "\n\t"
        "bis %[gie], SR"                    "\n\t"
        "nop"                               "\n\t"
        "and %[gie], %[state]"              "\n\t"
        : [state]   "=r"(state)
        : [gie]     "i"(_GENERAL_INTERRUPT_ENABLE)
        : "memory"
    );
 
    return state;
}
 
__attribute__((always_inline)) static inline void irq_restore(unsigned int state)
{
    __asm__ volatile(
        "bis %[state], SR"                    "\n\t"
        "nop"                                 "\n\t"
        : /* no outputs */
        : [state]   "r"(state)
        : "memory"
    );
}
 
__attribute__((always_inline)) static inline bool irq_is_in(void)
{
    return __irq_is_in;
}
 
__attribute__((always_inline)) static inline bool irq_is_enabled(void)
{
    unsigned int state;
    __asm__ volatile(
        "mov.w SR,%[state]"                   "\n\t"
        : [state]   "=r"(state)
        : /* no inputs */
        : "memory"
    );
 
    return (state & GIE);
}
 
#ifdef __cplusplus
}
#endif
 
#endif /* IRQ_ARCH_H */