path: root/memories/MEDRamDisk.c

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support 
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, 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,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */

//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------

#include "MEDRamDisk.h"
#include <board.h>
#include <utility/trace.h>

//------------------------------------------------------------------------------
//      Types
//------------------------------------------------------------------------------

/// Do copy and modify pointer
typedef void copyFunction(unsigned char **, unsigned char **, unsigned int);

//------------------------------------------------------------------------------
//      Internal Functions
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
/// Do copy for 8-byte aligned data
//------------------------------------------------------------------------------
static void AlignedCopy(unsigned char * *src,
                        unsigned char * *dst,
                        unsigned int len)
{
    unsigned int *src32, *dst32;
    src32 = (unsigned int*)*src;
    dst32 = (unsigned int*)*dst;
    for (;len > 0; len -= 8) {
        *dst32 ++ = *src32 ++;
        *dst32 ++ = *src32 ++;
    }
    *src = (unsigned char*)src32;
    *dst = (unsigned char*)dst32;
}

//------------------------------------------------------------------------------
/// Do copy for byte-aligned data
//------------------------------------------------------------------------------
static void UnalignedCopy(unsigned char * *src,
                          unsigned char * *dst,
                          unsigned int  len)
{
    for (;len > 0; len --) {
        *(*dst) ++ = *(*src) ++;
    }
}

//------------------------------------------------------------------------------
//! \brief  Reads a specified amount of data from a RAM Disk memory
//! \param  media    Pointer to a Media instance
//! \param  address  Address of the data to read
//! \param  data     Pointer to the buffer in which to store the retrieved
//!                   data
//! \param  length   Length of the buffer
//! \param  callback Optional pointer to a callback function to invoke when
//!                   the operation is finished
//! \param  argument Optional pointer to an argument for the callback
//! \return Operation result code
//------------------------------------------------------------------------------
static unsigned char MEDRamDisk_Read(Media         *media,
                                     unsigned int  address,
                                     void          *data,
                                     unsigned int  length,
                                     MediaCallback callback,
                                     void          *argument)
{
    unsigned char *source;
    unsigned char *dest;
    copyFunction  *pCpy;

    // Check that the media is ready
    if (media->state != MED_STATE_READY) {

        TRACE_INFO("Media busy\n\r");
        return MED_STATUS_BUSY;
    }

    // Check that the data to read is not too big
    if ((length + address) > media->size) {

        TRACE_WARNING("RamDisk_Read: Data too big: %u, 0x%08X\n\r",
                      length, address);
        return MED_STATUS_ERROR;
    }

    // Enter Busy state
    media->state = MED_STATE_BUSY;

    // Source & Destination
    source = (unsigned char *)(media->blockSize
                                    * (address + media->baseAddress));
    dest   = (unsigned char *)data;

    // Align/Unaligned copy
    pCpy   = (((unsigned int)source%4) == 0 && (media->blockSize%8) == 0)
                        ? AlignedCopy : UnalignedCopy;

    for (; length > 0; length --) {
        pCpy(&source, &dest, media->blockSize);
    }

    // Leave the Busy state
    media->state = MED_STATE_READY;

    // Invoke callback
    if (callback != 0) {

        callback(argument, MED_STATUS_SUCCESS, 0, 0);
    }

    return MED_STATUS_SUCCESS;
}

//------------------------------------------------------------------------------
//! \brief  Writes data on a Ram Disk media
//! \param  media    Pointer to a Media instance
//! \param  address  Address at which to write
//! \param  data     Pointer to the data to write
//! \param  length   Size of the data buffer
//! \param  callback Optional pointer to a callback function to invoke when
//!                   the write operation terminates
//! \param  argument Optional argument for the callback function
//! \return Operation result code
//! \see    Media
//! \see    MediaCallback
//------------------------------------------------------------------------------
static unsigned char MEDRamDisk_Write(Media         *media,
                                      unsigned int  address,
                                      void          *data,
                                      unsigned int  length,
                                      MediaCallback callback,
                                      void          *argument)
{
    unsigned char *source;
    unsigned char *dest;
    copyFunction  *pCpy;

    //TRACE_DEBUG("RamDisk_Write\n\r");

    // Check that the media if ready
    if (media->state != MED_STATE_READY) {

        TRACE_WARNING("RamDisk_Write: busy\n\r");
        return MED_STATUS_BUSY;
    }

    // Check that the data to write is not too big
    if ((length + address) > media->size) {

        TRACE_WARNING("RamDisk_Write: Data too big\n\r");
        return MED_STATUS_ERROR;
    }

    // Put the media in Busy state
    media->state = MED_STATE_BUSY;

    // Compute function parameters
    source = (unsigned char *) data;
    dest = (unsigned char *) (media->blockSize * 
                                    (media->baseAddress + address));

    // Align/Unaligned copy
    pCpy   = (((unsigned int)source%4) == 0 && (media->blockSize%8) == 0)
                        ? AlignedCopy : UnalignedCopy;

    for (; length > 0; length --) {
        pCpy(&source, &dest, media->blockSize);
    }

    // Leave the Busy state
    media->state = MED_STATE_READY;

    // Invoke the callback if it exists
    if (callback != 0) {

        callback(argument, MED_STATUS_SUCCESS, 0, 0);
    }

    return MED_STATUS_SUCCESS;
}

//------------------------------------------------------------------------------
//      Exported Functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//! \brief  Initializes a Media instance and the associated physical interface
//! \param  media Pointer to the Media instance to initialize
//! \return 1 if initialize sucessfully, 0 if any error.
//! \see    Media
//------------------------------------------------------------------------------
unsigned char MEDRamDisk_Initialize(Media *media,
                                    unsigned int blockSize,
                                    unsigned int baseAddress,
                                    unsigned int size)
{
    unsigned int bak_val;
    unsigned int baseInBytes = baseAddress * blockSize;
    unsigned int sizeInBytes = size * blockSize;

    TRACE_INFO("RAM Disk init\n\r");

    // If the address Initialized ?
    bak_val = *((volatile unsigned int *) (baseInBytes));
    *((volatile unsigned int *) (baseInBytes)) = 0xDEADBEEF;
    if (*((volatile unsigned int *) baseInBytes) == 0xDEADBEEF) {

        *((volatile unsigned int *) baseInBytes) = bak_val;
    }
    else {

        TRACE_ERROR("Un-configured memory area %x ...\n\r", baseInBytes);
        return 0;
    }

    baseInBytes += sizeInBytes - 4;
    bak_val = *((volatile unsigned int *) (baseInBytes));
    *((volatile unsigned int *) (baseInBytes)) = 0xAECDBE9F;
    if (*((volatile unsigned int *)(baseInBytes)) == 0xAECDBE9F) {

        *((volatile unsigned int *)(baseInBytes)) = bak_val;
    }
    else {

        TRACE_ERROR("Un-configured memory area %x ...\n\r", baseInBytes);
        return 0;
    }

    // Initialize media fields
    media->write = MEDRamDisk_Write;
    media->read = MEDRamDisk_Read;
    media->lock = 0;
    media->unlock = 0;
    media->handler = 0;
    media->flush = 0;

    media->blockSize = blockSize;
    media->baseAddress = baseAddress;
    media->size = size;

    media->mappedRD  = 0;
    media->mappedWR  = 0;
    media->protected = 0;
    media->removable = 0;
    media->state = MED_STATE_READY;

    media->transfer.data = 0;
    media->transfer.address = 0;
    media->transfer.length = 0;
    media->transfer.callback = 0;
    media->transfer.argument = 0;
    
    return 1;
}