root/trunk/freebob/src/avdescriptor.cpp

/* avdescriptor.cpp
 * Copyright (C) 2004 by Pieter Palmers
 *
 * This file is part of FreeBob.
 *
 * FreeBob is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * FreeBob is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with FreeBob; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA.
 */

#include "avdescriptor.h"
#include <string.h>
#include <errno.h>
#include <libavc1394/avc1394.h>
#include <libavc1394/avc1394_vcr.h>
#include "debugmodule.h"

/* should probably be attached to an AVC device, 
   a descriptor is attached to an AVC device anyway.
   
   a descriptor also always has a type
*/

AvDescriptor::AvDescriptor(AvDevice *parent, quadlet_t target, unsigned int type)
{
        cParent=parent;
        iType=type;
        qTarget=target;
        aContents=NULL;
        bLoaded=false;
        iLength=0;
        bOpen=false;
        iAccessType=0;
        bValid=false; // don't know yet what I'm going to do with this in the generic descriptor
}

AvDescriptor::~AvDescriptor()
{
        if (bOpen) {
                Close();
        }
        if (aContents) {
                delete aContents;
        }

}

void AvDescriptor::OpenReadOnly() {
        quadlet_t *response;
        quadlet_t request[3];   
        
        if (!cParent) {
                return;
        }
        
        if(isOpen()) {
                Close();
        }
        
        request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                        | AVC1394_COMMAND_OPEN_DESCRIPTOR | (iType & 0xFF);
        request[1] = 0x01FFFFFF;
        //fprintf(stderr, "Opening descriptor\n");
        
        response =  cParent->avcExecuteTransaction(request, 2, 2);
        
        if ((response[0]&0xFF000000)==AVC1394_RESPONSE_ACCEPTED) {
                bOpen=true;
                iAccessType=0x01;
        } else {
                Close();
                bOpen=false;
        }
}

void AvDescriptor::OpenReadWrite() {
        quadlet_t *response;
        quadlet_t request[3];   
        
        if (!cParent) {
                return;
        }
        
        if(isOpen()) {
                Close();
        }
                
        request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                        | AVC1394_COMMAND_OPEN_DESCRIPTOR | (iType & 0xFF);
        request[1] = 0x03FFFFFF;
        //fprintf(stderr, "Opening descriptor\n");
        
        response =  cParent->avcExecuteTransaction(request, 2, 2);
        
        if ((response[0]&0xFF000000)==AVC1394_RESPONSE_ACCEPTED) {
                bOpen=true;
                iAccessType=0x03;
        } else {
                Close();
                bOpen=false;
        }
}

bool AvDescriptor::canWrite() {
        if(bOpen && (iAccessType==0x03) && cParent) {
                return true;
        } else {
                return false;
        }
}

void AvDescriptor::Close() {
        quadlet_t *response;
        quadlet_t request[3];   
        if (!cParent) {
                return;
        }       
        request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                        | AVC1394_COMMAND_OPEN_DESCRIPTOR | (iType & 0xFF);
        request[1] = 0x00FFFFFF;
        //fprintf(stderr, "Opening descriptor\n");
        
        response =  cParent->avcExecuteTransaction(request, 2, 2);
        
        if ((response[0]&0xFF000000)==AVC1394_RESPONSE_ACCEPTED) { // should always be accepted according to spec
                bOpen=false;
        }
}

/* Load the descriptor
 * no error checking yet
 */

void AvDescriptor::Load() {
        quadlet_t *response;
        quadlet_t request[3];   
        unsigned int i=0;
        unsigned int bytes_read=0;
        unsigned char *databuffer;
        unsigned char read_result_status;
        unsigned int data_length_read;
        
        if (!cParent) {
                return;
        }
        
        /* First determine the descriptor length */
        request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                        | AVC1394_COMMAND_READ_DESCRIPTOR | (iType & 0xFF);
        request[1] = 0xFFFF0000 | (0x02);
        request[2] = (((0)&0xFFFF) << 16) |0x0000FFFF;
        response =  cParent->avcExecuteTransaction(request, 3, 3);

        iLength=response[2] & 0xFFFF;
        
        fprintf(stderr,"Descriptor length=0x%04X %d\n",iLength,iLength);        

        // now get the rest of the descriptor
        aContents=new unsigned char[iLength];
        
        /* there is a gap in the read data, because of the two bytes 
         * that are before the third quadlet (why did 1394TA do that?)
         * 
         * proposed solution:
         * 1) the first read is OK, because the length of the descriptor is in these two bytes,
         *    so execute a read from address 0 with length=iLength
         * 2) process the bytes starting from response[3]
         * 3) the next reads should start from the end of the previous read minus 2. this way we 
         *    can discard these two problem bytes, because they are already read in the previous 
         *    run.
         */
        
        // first read
        if(bytes_read<iLength) {
                fprintf(stderr,".");    
                // apparently the lib modifies the request, so redefine it completely
                request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                                | AVC1394_COMMAND_READ_DESCRIPTOR | (iType & 0xFF);
                // the amount of bytes we want to read is:
                //  total descriptor length + 2 bytes of the descriptor length field (i.e. the overlap bytes for this read)
                request[1] = 0xFFFF0000 | (iLength)&0xFFFF;
                request[2] = ((0) << 16) |0x0000FFFF;
                
                response =  cParent->avcExecuteTransaction(request, 3, 3);
                data_length_read=(response[1]&0xFFFF);
                read_result_status=((response[1]>>24)&0xFF);
                
                databuffer=(unsigned char *)(response+3);
                
                // the buffer starting at databuffer is two bytes smaller that the amount of bytes read
                for (i=0;(i<data_length_read-2) && (bytes_read < iLength);i++) {
                        *(aContents+bytes_read)=*(databuffer+i);
                        bytes_read++;
                }
                
        }
        
        // now do the remaining reads
        while(bytes_read<iLength) {
                fprintf(stderr,".");    
                // apparently the lib modifies the request, so redefine it completely
                request[0] = AVC1394_CTYPE_CONTROL | qTarget
                                                | AVC1394_COMMAND_READ_DESCRIPTOR | (iType & 0xFF);
                // the amount of bytes we want to read is:
                //  (total descriptor length - number of bytes already read) + 2 overlap with previous read
                request[1] = 0xFFFF0000 | (iLength-bytes_read+2)&0xFFFF;
                request[2] = (((bytes_read)&0xFFFF) << 16) |0x0000FFFF;
                
                response =  cParent->avcExecuteTransaction(request, 3, 3);
                data_length_read=(response[1]&0xFFFF);
                read_result_status=((response[1]>>24)&0xFF);
                
                databuffer=(unsigned char *)(response+3);
                
                for (i=0;(i<data_length_read-2) && (bytes_read < iLength);i++) {
                        *(aContents+bytes_read)=*(databuffer+i);
                        bytes_read++;
                }
                
        }
        fprintf(stderr,"\n");   
        
        
        bLoaded=true;
}

bool AvDescriptor::isPresent() {
        quadlet_t *response;
        quadlet_t request[2];   
        
        if (!cParent) {
                return false;
        }
        
        request[0] = AVC1394_CTYPE_STATUS | qTarget | AVC1394_COMMAND_OPEN_DESCRIPTOR | (iType & 0xFF);
        request[1] = 0xFFFFFFFF;
        response =  cParent->avcExecuteTransaction(request, 2, 2);

        if (((response[0] & 0xFF000000)==AVC1394_RESPONSE_NOT_IMPLEMENTED) || ((response[1] & 0xFF000000)==0x04)) { 
                fprintf(stderr,"Descriptor not present.\n");
                bValid=false;
                return false;
        } 
        return true;
}


bool AvDescriptor::isOpen() {
        // maybe we should check this on the device instead of mirroring locally...
        // after all it can time out
        return bOpen;
}

bool AvDescriptor::isLoaded() {
        return bLoaded;
}

bool AvDescriptor::isValid() {
        return bValid;
}


unsigned int AvDescriptor::getLength() {
        return iLength;
}

unsigned char AvDescriptor::readByte(unsigned int address) {
        if(cParent && bLoaded && aContents) {
                return *(aContents+address);
        } else {
                return 0; // what to do with this?
        }
}

unsigned int AvDescriptor::readWord(unsigned int address) {
        unsigned int word;
        
        if(cParent && bLoaded && aContents) {
                word=(*(aContents+address)<<8)+*(aContents+address+1);
                return word;
        } else {
                return 0; // what to do with this?
        }
}

unsigned int AvDescriptor::readBuffer(unsigned int address, unsigned int length, unsigned char *buffer) {
        if(cParent && bLoaded && aContents && address < iLength) {
                if(address+length>iLength) {
                        length=iLength-address;
                }
                memcpy((void*)buffer, (void*)(aContents+address), length);
                return length;
                
        } else {
                return 0;
        }
}