dmad.c

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/* ----------------------------------------------------------------------------
 *         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 "dmad.h"
#include <dma/dma.h>
#include <aic/aic.h>
#include <utility/assert.h>
#include <utility/trace.h>

//------------------------------------------------------------------------------
//         Local types
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// DMA transfer descriptor. Tracks the status and parameters of a transfer
/// on the DMA bus.
//------------------------------------------------------------------------------
typedef struct _DmaTransfer {
    /// Buffer transfer status.
    volatile unsigned char status;
    /// Transfer buffer size in byte.
    unsigned int bufSize;
    /// Total transfer size to byte.
    volatile unsigned int transferSize;
    /// Optional callback function.
    DmaCallback callback;
} DmaTransfer;

//------------------------------------------------------------------------------
/// DMAD driver structure. Monitors the status of transfers on all
/// DMA channels.
//------------------------------------------------------------------------------
typedef struct _Dmad {

    /// List of transfers occuring on each channel.
    DmaTransfer transfers[2];
} Dmad;

//------------------------------------------------------------------------------
//         Local variables
//------------------------------------------------------------------------------

/// Global DMA transfer instance.
static Dmad dmad;

//------------------------------------------------------------------------------
//         Local functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// This handler function must be called by the DMAC interrupt service routine.
/// Identifies which event was activated and calls the associated function.
//------------------------------------------------------------------------------ 
void DMAD_Handler()
{
    unsigned int status;
    unsigned char channel;
     DmaTransfer *pTransfer;
    status = DMA_GetStatus();
    // Check if the buffer transfer completed is set.
    if(status & AT91C_BTC)
    {
        // Scan each channel status.
        for(channel = 0; channel < DMA_CHANNEL_NUM; channel++) {
            if(!(status & (DMA_BTC << channel))){
                continue;
            }
            
            dmad.transfers[channel].transferSize -= dmad.transfers[channel].bufSize;
            // if next buffer is to be the last buffer in the transfer, then clear the automatic mode bit.
            if(dmad.transfers[channel].transferSize <= dmad.transfers[channel].bufSize) {
                DMA_ClearAutoMode(channel);
            }
            // Transfer finished
            if(dmad.transfers[channel].transferSize == 0) {
                pTransfer = &(dmad.transfers[channel]);
                pTransfer->callback();
                DMA_DisableIt(DMA_BTC << channel); 
                DMA_DisableChannel(channel);
            }
            else
            {
                // Write the KEEPON field to clear the STALL states.
                DMA_KeeponChannel(channel);
            }
        }
    }
}

//------------------------------------------------------------------------------
/// Initializes the DMA controller.
/// \param channel Particular channel number.
//------------------------------------------------------------------------------
void DMAD_Initialize(unsigned char channel)
{
    unsigned int status;
     
    // Read the channel handler status to ensure the channel is a free channel.
    status = DMA_GetChannelStatus();
    TRACE_INFO ("DMAD_Initialize channel %x  \n\r", channel);
    SANITY_CHECK(!(status & (1 << channel)));
    // Clear any pending interrupts on the channel.
    DMA_GetStatus();
    // Disble the channel.
	DMA_DisableChannel(channel);
    // Enable DMA.
    DMA_Enable();
    AIC_ConfigureIT(AT91C_ID_HDMA, 0, DMAD_Handler);
    AIC_EnableIT(AT91C_ID_HDMA);
    // Initialize transfer instance.
    dmad.transfers[channel].transferSize = 0;
}
 
//------------------------------------------------------------------------------
/// Configure the DMA transfer buffer by giving transfer mode, it could be single 
/// buffer or multi-buffer(LLI/auto-reload/contiguous buffers) with or without 
/// Picture-In-Picture mode.
/// \param channel Particular channel number.
/// \param sourceTransferMode Source buffer transfer mode.
/// \param destTransferMode Destination buffer transfer mode.
/// \param lli Pointer to a DmaLinkList structure instance.
/// \param pip Pointer to a PictureInPicture structure.
//------------------------------------------------------------------------------
unsigned char DMAD_Configure_Buffer(unsigned char channel,
                           unsigned char sourceTransferMode,
                           unsigned char destTransferMode,
                           DmaLinkList *lli,
                           PictureInPicture *pip)
{
    DmaTransfer *pTransfer = &(dmad.transfers[channel]);
    // Check that no transfer is pending on the channel
    if (pTransfer-> transferSize > 0 ) {
        TRACE_ERROR("DAM transfer is already pending\n\r");
        return DMAD_ERROR_BUSY;
    }
    // Configure source transfer mode.
    DMA_SetSourceBufferMode(channel, sourceTransferMode, 0);
    
    // Configure destination transfer mode.
    DMA_SetDestBufferMode(channel, destTransferMode, 0);
    
    if(lli){
        DMA_SetDescriptorAddr(channel, (unsigned int)(&lli[0]));
    }
    else {
        DMA_SetDescriptorAddr(channel, 0);
    }
    
    if(pip){
        // If source picture-in-picture mode is enabled, program the DMAC_SPIP.
        if(pip->pipSourceBoundarySize){
        // If destination picture-in-picture mode is enabled, program the DMAC_DPIP.
            DMA_SPIPconfiguration(channel, pip->pipSourceHoleSize, pip->pipSourceBoundarySize);
        }
        if(pip->pipDestBoundarySize){
            DMA_DPIPconfiguration(channel, pip->pipDestHoleSize, pip->pipDestBoundarySize);
        }
    }
    return 0;
}

//------------------------------------------------------------------------------
/// Configure the DMA transfer control infomation.
/// \param channel Particular channel number.
/// \param bufSize Buffer transfer size in byte.
/// \param sourceWidth Source transfer width.
/// \param destWidth Destination transfer width.
/// \param sourceAddress Destination transfer width.
/// \param destAddress Destination transfer width.
//------------------------------------------------------------------------------
unsigned char DMAD_Configure_TransferController(unsigned char channel,
                                      unsigned int bufSize,
                                      unsigned char sourceWidth,
                                      unsigned char destWidth,
                                      unsigned int sourceAddress,
                                      unsigned int destAddress)
{
    DmaTransfer *pTransfer = &(dmad.transfers[channel]);
    // Check that no transfer is pending on the channel
    if (pTransfer-> transferSize > 0 ) {
        TRACE_ERROR("DAM transfer is already pending\n\r");
        return DMAD_ERROR_BUSY;
    }
    pTransfer->bufSize = bufSize; 
    
    // Set up the transfer width and transfer size.
    DMA_SetSourceBufferSize(channel, bufSize, sourceWidth, destWidth, 0);

    if(sourceAddress) {
        // Write the starting source address.
        DMA_SetSourceAddr(channel, sourceAddress);
    }
    if(destAddress){
        // Write the starting destination address.
        DMA_SetDestinationAddr(channel, destAddress);
    }
    return 0;
}                                 
                           
//------------------------------------------------------------------------------
/// Starts buffer transfer on the given channel
/// \param channel Particular channel number.
/// \param size Total transfer size in byte.
/// \param callback Optional callback function.
/// \param polling Polling channel status enable.
//------------------------------------------------------------------------------
unsigned char DMAD_BufferTransfer(unsigned char channel, 
                                  unsigned int size, 
                                  DmaCallback callback, 
                                  unsigned char polling)
{
    DmaTransfer *pTransfer = &(dmad.transfers[channel]);
    // Check that no transfer is pending on the channel
    if (pTransfer-> transferSize > 0 ) {
        TRACE_ERROR("DAM transfer is already pending\n\r");
        return DMAD_ERROR_BUSY;
    }
    pTransfer->status = DMAD_ERROR_BUSY; 
    pTransfer->transferSize = size;
    pTransfer->callback = callback; 
    
    if(!polling){
        DMA_EnableIt(DMA_BTC << channel);
    }
    // Enable the channel.
    DMA_EnableChannel(channel);
    
    if(polling){
        while ((DMA_GetChannelStatus() & (DMA_ENA << channel)) == (DMA_ENA << channel));
        pTransfer->callback();
        DMA_DisableChannel(channel);
    }
    return 0;
}

//------------------------------------------------------------------------------
/// Returns 1 if no transfer is currently pending on the given channel;
/// otherwise, returns 0.
/// \param channel  Channel number.
//------------------------------------------------------------------------------
unsigned char DMAD_IsFinished(unsigned char channel)
{
    SANITY_CHECK(channel <= DMA_CHANNEL_1);
    if (dmad.transfers[channel].transferSize > 0) {
        return 0;
    }
    else {
        DMA_DisableChannel(channel);
        return 1;
    }
}