/*
 * Copyright (C) 2013, Freie Universitaet Berlin (FUB). All rights reserved.
 *
 * 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 _CPU_H
#define _CPU_H

/**
 * @defgroup    msp430 TI MSP430
 * @ingroup     cpu
 * @brief       Texas Instruments MSP430 specific code

<h2>First steps</h2>
\li See the <a href="../manual/index.html">manual</a> for toolchain and ide setup

 * @{
 */

#include <stdio.h>
#include <legacymsp430.h>

#include <msp430.h>
#include "board.h"

#include "sched.h"
#include "msp430_types.h"
#include "cpu-conf.h"

#define WORDSIZE 16

extern volatile int __inISR;
extern char __isr_stack[MSP430_ISR_STACK_SIZE];

//#define eINT()  eint()
//#define dINT()  dint()

inline void __save_context_isr(void)
{
    __asm__("push r15");
    __asm__("push r14");
    __asm__("push r13");
    __asm__("push r12");
    __asm__("push r11");
    __asm__("push r10");
    __asm__("push r9");
    __asm__("push r8");
    __asm__("push r7");
    __asm__("push r6");
    __asm__("push r5");
    __asm__("push r4");

    __asm__("mov.w r1,%0" : "=r"(sched_active_thread->sp));
}

inline void __restore_context_isr(void)
{
    __asm__("mov.w %0,r1" : : "m"(sched_active_thread->sp));

    __asm__("pop r4");
    __asm__("pop r5");
    __asm__("pop r6");
    __asm__("pop r7");
    __asm__("pop r8");
    __asm__("pop r9");
    __asm__("pop r10");
    __asm__("pop r11");
    __asm__("pop r12");
    __asm__("pop r13");
    __asm__("pop r14");
    __asm__("pop r15");
}

inline void __enter_isr(void)
{
    __save_context_isr();
    __asm__("mov.w %0,r1" : : "i"(__isr_stack+MSP430_ISR_STACK_SIZE));
    __inISR = 1;
}

inline void __exit_isr(void)
{
    __inISR = 0;

    if (sched_context_switch_request) {
        sched_run();
    }

    __restore_context_isr();
    __asm__("reti");
}

inline void __save_context(void)
{
    __asm__("push r2"); /* save SR */
    __save_context_isr();
}

inline void __restore_context(unsigned int irqen)
{
    __restore_context_isr();

    /* we want to enable if appropriate IRQs *just after*
       quitting the interrupt handler; to that end,
       we change the GIE bit in the value to be restored
       in R2 (a.k.a. SR) by the next RETI instruction */
    if (irqen) {
        __asm__("bis.w #8, 0(r1)");
    } else {
        __asm__("bic.w #8, 0(r1)");
    }

    __asm__("reti");
}

inline void eINT(void)
{
    //    puts("+");
    eint();
}

inline void dINT(void)
{
    //    puts("-");
    dint();
}

int inISR(void);

void msp430_cpu_init(void);

/** @} */
#endif // _CPU_H