//*****************************************************************************
//
// cpu.c - Instruction wrappers for special CPU instructions needed by the
//         drivers.
//
// Copyright (c) 2006-2010 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
// 
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 6288 of the Stellaris Peripheral Driver Library.
//
//*****************************************************************************

#include "driverlib/cpu.h"

//*****************************************************************************
//
// Wrapper function for the CPSID instruction.  Returns the state of PRIMASK
// on entry.
//
//*****************************************************************************
#if defined(codered) || defined(gcc) || defined(sourcerygxx)
unsigned long __attribute__((naked))
CPUcpsid(void)
{
    unsigned long ulRet;

    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsid   i\n"
          "    bx      lr\n"
          : "=r" (ulRet));

    //
    // The return is handled in the inline assembly, but the compiler will
    // still complain if there is not an explicit return here (despite the fact
    // that this does not result in any code being produced because of the
    // naked attribute).
    //
    return(ulRet);
}
#endif
#if defined(ewarm)
unsigned long
CPUcpsid(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsid   i\n");

    //
    // "Warning[Pe940]: missing return statement at end of non-void function"
    // is suppressed here to avoid putting a "bx lr" in the inline assembly
    // above and a superfluous return statement here.
    //
#pragma diag_suppress=Pe940
}
#pragma diag_default=Pe940
#endif
#if defined(rvmdk) || defined(__ARMCC_VERSION)
__asm unsigned long
CPUcpsid(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    mrs     r0, PRIMASK;
    cpsid   i;
    bx      lr
}
#endif
#if defined(ccs)
unsigned long
CPUcpsid(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsid   i\n"
          "    bx      lr\n");

    //
    // The following keeps the compiler happy, because it wants to see a
    // return value from this function.  It will generate code to return
    // a zero.  However, the real return is the "bx lr" above, so the
    // return(0) is never executed and the function returns with the value
    // you expect in R0.
    //
    return(0);
}
#endif

//*****************************************************************************
//
// Wrapper function returning the state of PRIMASK (indicating whether
// interrupts are enabled or disabled).
//
//*****************************************************************************
#if defined(codered) || defined(gcc) || defined(sourcerygxx)
unsigned long __attribute__((naked))
CPUprimask(void)
{
    unsigned long ulRet;

    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    bx      lr\n"
          : "=r" (ulRet));

    //
    // The return is handled in the inline assembly, but the compiler will
    // still complain if there is not an explicit return here (despite the fact
    // that this does not result in any code being produced because of the
    // naked attribute).
    //
    return(ulRet);
}
#endif
#if defined(ewarm)
unsigned long
CPUprimask(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n");

    //
    // "Warning[Pe940]: missing return statement at end of non-void function"
    // is suppressed here to avoid putting a "bx lr" in the inline assembly
    // above and a superfluous return statement here.
    //
#pragma diag_suppress=Pe940
}
#pragma diag_default=Pe940
#endif
#if defined(rvmdk) || defined(__ARMCC_VERSION)
__asm unsigned long
CPUprimask(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    mrs     r0, PRIMASK;
    bx      lr
}
#endif
#if defined(ccs)
unsigned long
CPUprimask(void)
{
    //
    // Read PRIMASK and disable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    bx      lr\n");

    //
    // The following keeps the compiler happy, because it wants to see a
    // return value from this function.  It will generate code to return
    // a zero.  However, the real return is the "bx lr" above, so the
    // return(0) is never executed and the function returns with the value
    // you expect in R0.
    //
    return(0);
}
#endif

//*****************************************************************************
//
// Wrapper function for the CPSIE instruction.  Returns the state of PRIMASK
// on entry.
//
//*****************************************************************************
#if defined(codered) || defined(gcc) || defined(sourcerygxx)
unsigned long __attribute__((naked))
CPUcpsie(void)
{
    unsigned long ulRet;

    //
    // Read PRIMASK and enable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsie   i\n"
          "    bx      lr\n"
          : "=r" (ulRet));

    //
    // The return is handled in the inline assembly, but the compiler will
    // still complain if there is not an explicit return here (despite the fact
    // that this does not result in any code being produced because of the
    // naked attribute).
    //
    return(ulRet);
}
#endif
#if defined(ewarm)
unsigned long
CPUcpsie(void)
{
    //
    // Read PRIMASK and enable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsie   i\n");

    //
    // "Warning[Pe940]: missing return statement at end of non-void function"
    // is suppressed here to avoid putting a "bx lr" in the inline assembly
    // above and a superfluous return statement here.
    //
#pragma diag_suppress=Pe940
}
#pragma diag_default=Pe940
#endif
#if defined(rvmdk) || defined(__ARMCC_VERSION)
__asm unsigned long
CPUcpsie(void)
{
    //
    // Read PRIMASK and enable interrupts.
    //
    mrs     r0, PRIMASK;
    cpsie   i;
    bx      lr
}
#endif
#if defined(ccs)
unsigned long
CPUcpsie(void)
{
    //
    // Read PRIMASK and enable interrupts.
    //
    __asm("    mrs     r0, PRIMASK\n"
          "    cpsie   i\n"
          "    bx      lr\n");

    //
    // The following keeps the compiler happy, because it wants to see a
    // return value from this function.  It will generate code to return
    // a zero.  However, the real return is the "bx lr" above, so the
    // return(0) is never executed and the function returns with the value
    // you expect in R0.
    //
    return(0);
}
#endif

//*****************************************************************************
//
// Wrapper function for the WFI instruction.
//
//*****************************************************************************
#if defined(codered) || defined(gcc) || defined(sourcerygxx)
void __attribute__((naked))
CPUwfi(void)
{
    //
    // Wait for the next interrupt.
    //
    __asm("    wfi\n"
          "    bx      lr\n");
}
#endif
#if defined(ewarm)
void
CPUwfi(void)
{
    //
    // Wait for the next interrupt.
    //
    __asm("    wfi\n");
}
#endif
#if defined(rvmdk) || defined(__ARMCC_VERSION)
__asm void
CPUwfi(void)
{
    //
    // Wait for the next interrupt.
    //
    wfi;
    bx      lr
}
#endif
#if defined(ccs)
void
CPUwfi(void)
{
    //
    // Wait for the next interrupt.
    //
    __asm("    wfi\n");
}
#endif
