/* ----------------------------------------------------------------------------
 *         SAM Software Package License  
 * ----------------------------------------------------------------------------
 * Copyright (c) 2011, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 */

//-----------------------------------------------------------------------------
// Reg Reads                    Writes
//----------------------------------------------------------------------------
// 0   ID code                  Unpredictable
// 0   cache type               Unpredictable
// 0   TCM status               Unpredictable
// 1   Control                  Control
// 2   Translation table base   Translation table base
// 3   Domain access control    Domain access control
// 4                                                       (Reserved)
// 5   Data fault status        Data fault status
// 5   Instruction fault status Instruction fault status
// 6   Fault address            Fault address
// 7   cache operations         cache operations
// 8   Unpredictable            TLB operations
// 9   cache lockdown           cache lockdown
// 9   TCM region               TCM region
// 10  TLB lockdown             TLB lockdown
// 11                                                      (Reserved) 
// 12                                                      (Reserved) 
// 13  FCSE PID                 FCSE PID
// 13  Context ID               Context ID
// 14                                                      (Reserved)
// 15  Test configuration       Test configuration
//-----------------------------------------------------------------------------


/** \page cp15_f CP15 Functions.
 *
 * \section CP15 function Usage
 *
 * Methods to manage the Coprocessor 15. Coprocessor 15, or System Control 
 * Coprocessor CP15, is used to configure and control all the items in the 
 * list below:
 * <ul>
 * <li> ARM core
 * <li> caches (Icache, Dcache and write buffer)
 * <li> TCM
 * <li> MMU
 * <li> Other system options
 * </ul>
 * \section Usage
 *
 * -# Enable or disable D cache with Enable_D_cache and Disable_D_cache
 * -# Enable or disable I cache with Enable_I_cache and Disable_I_cache
 *
 * Related files:\n
 * \ref cp15.h\n
 * \ref cp15.c.\n
 */

/** \file */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "chip.h"
#if defined(__ICCARM__)
  #include <intrinsics.h>
#endif
/*----------------------------------------------------------------------------
 *        Global functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Check Instruction cache
 * \return 0 if I_cache disable, 1 if I_cache enable
 */
unsigned int CP15_IsIcacheEnabled(void)
{
    unsigned int control;

    control = CP15_ReadControl();
    return ((control & (1 << CP15_I_BIT)) != 0);
} 


/**
 * \brief  Enable Instruction cache
 */
void CP15_EnableIcache(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    // Check if cache is disabled
    if ((control & (1 << CP15_I_BIT)) == 0) {

        control |= (1 << CP15_I_BIT);
        CP15_WriteControl(control);
        TRACE_INFO("I cache enabled.\n\r");
    }
#if !defined(OP_BOOTSTRAP_on)
    else {

        TRACE_INFO("I cache is already enabled.\n\r");
    }
#endif
}


/**
 * \brief  Disable Instruction cache
 */
void CP15_DisableIcache(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    // Check if cache is enabled
    if ((control & (1 << CP15_I_BIT)) != 0) {

        control &= ~(1ul << CP15_I_BIT);
        CP15_WriteControl(control);        
        TRACE_INFO("I cache disabled.\n\r");
    }
    else {

        TRACE_INFO("I cache is already disabled.\n\r");
    }
} 

/**
 * \brief  Check MMU
 * \return  0 if MMU disable, 1 if MMU enable
 */
unsigned int CP15_IsMMUEnabled(void)
{
    unsigned int control;

    control = CP15_ReadControl();
    return ((control & (1 << CP15_M_BIT)) != 0);
} 


/**
 * \brief  Enable MMU
 */
void CP15_EnableMMU(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    // Check if MMU is disabled
    if ((control & (1 << CP15_M_BIT)) == 0) {

        control |= (1 << CP15_M_BIT);
        CP15_WriteControl(control);        
        TRACE_INFO("MMU enabled.\n\r");
    }
    else {

        TRACE_INFO("MMU is already enabled.\n\r");
    }
}


/**
 * \brief  Disable MMU
 */
void CP15_DisableMMU(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    // Check if MMU is enabled
    if ((control & (1 << CP15_M_BIT)) != 0) {

        control &= ~(1ul << CP15_M_BIT);
        control &= ~(1ul << CP15_C_BIT);
        CP15_WriteControl(control);        
        TRACE_INFO("MMU disabled.\n\r");
    }
    else {

        TRACE_INFO("MMU is already disabled.\n\r");
    }
}


/**
 * \brief  Check D_cache
 * \return  0 if D_cache disable, 1 if D_cache enable (with MMU of course)
 */
unsigned int CP15_IsDcacheEnabled(void)
{
    unsigned int control;

    control = CP15_ReadControl();
    return ((control & ((1 << CP15_C_BIT)||(1 << CP15_M_BIT))) != 0);
} 

/**
 * \brief  Enable Data cache
 */
void CP15_EnableDcache(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    if( !CP15_IsMMUEnabled() ) {
        TRACE_ERROR("Do nothing: MMU not enabled\n\r");
    }
    else {
        // Check if cache is disabled
        if ((control & (1 << CP15_C_BIT)) == 0) {

            control |= (1 << CP15_C_BIT);
            CP15_WriteControl(control);        
            TRACE_INFO("D cache enabled.\n\r");
        }
        else {

            TRACE_INFO("D cache is already enabled.\n\r");
        }
    }
}

/**
 * \brief  Disable Data cache
 */
void CP15_DisableDcache(void)
{
    unsigned int control;

    control = CP15_ReadControl();

    // Check if cache is enabled
    if ((control & (1 << CP15_C_BIT)) != 0) {

        control &= ~(1ul << CP15_C_BIT);
        CP15_WriteControl(control);
        TRACE_INFO("D cache disabled.\n\r");
    }
    else {

        TRACE_INFO("D cache is already disabled.\n\r");
    }
}


