[Libusb-devel] Re: DMA read

[shino k. <shi...@ya...>]

> Could you quantify "first few bytes"?
> 
> And maybe show some sample code?
> 
> It's very difficult to offer any useful help when
> the description is so
> vague.
> 
> JE

Sorry about that.
This is my DMA_WRITE function.
It sets couple of registers and then write to bulk_out
endpoint.

fewbytes = 100 to 200 bytes. I couldn't count the
exact number. that is why I wrote like that.

int
DMA_Write (usb_dev_handle * mydev)
{
  //dmactl read
  int rc, i,flag,j;
  unsigned char r1val[0x1000];
  unsigned char val[6] = { 0x17, 0x00, 0x30, 0x03,
0x00, 0x00 };        //to read dmactl register
  unsigned char val5[6]={0x1f, 0x00, 0x24, 0x03, 0x00,
0x00 };
unsigned char val6[10]= { 0x1f, 0x00, 0x24, 0x03,
0x00, 0x00, 0xff, 0x00, 0x00, 0x00 }; //set ep_rsp
  unsigned char val1[10] = { 0x1f, 0x00, 0x80, 0x01,
0x00, 0x00, 0x16, 0x00, 0x28, 0x00 };      //set dma
ctl
  unsigned char val2[10] = { 0x1f, 0x00, 0x90, 0x01,
0x00, 0x00, 0x00, 0x00, 0x10, 0x00 };      //set dma
count
  unsigned char val3[10] = { 0x1f, 0x00, 0x94, 0x01,
0x00, 0x00, 0x00, 0x00, 0x10, 0x00 };      //set dma
address
 unsigned char val4[10] = { 0x1f, 0x00, 0x84, 0x01,
0x00, 0x00, 0x01, 0x00, 0x00, 0x00 };       //set dma
stat to start bit

 for(i=0;i<=0x1000;i++){
   r1val[i]=0xaa;
 }


  Write_Register (0x0d, val1, 10, mydev);      
//writing dmactl register
  Write_Register (0x0d, val2, 10, mydev);      
//writing dmacount register

  Write_Register (0x0d, val3, 10, mydev);      
//writing dmaaddress register
  Write_Register (0x0d, val6, 10, mydev);//write
ep_rsp

  Write_Register (0x0d, val4, 10, mydev);      
//writing dma start register

  rc = usb_bulk_write (mydev, 0x01, r1val, 0x1000,
1000);
  if (rc < 0)
    {
      printf ("%s\n", usb_strerror ());
    }

  return 0;
}



DMA_READ function

reads from the same exact location.

int
DMA_Read (usb_dev_handle * mydev)
{
  //dmactl read
  int rc, i,flag,j;
  unsigned char r1val[0x1000];
  //I have register initilization here
 // printf("DMA read\n");
  Write_Register (0x0d, val1, 10, mydev);      
//writing dmactl register
  Write_Register (0x0d, val2, 10, mydev);      
//writing dmacount register

  Write_Register (0x0d, val3, 10, mydev);      
//writing dmaaddress register
  Write_Register (0x0d, val6, 10, mydev);//write
ep_rsp
  
  Write_Register (0x0d, val4, 10, mydev);      
//writing dma start register
    rc = usb_bulk_read (mydev, 0x82, r1val, 0x1000,
2000);
     
  if (rc < 0)
    {
      printf ("%s\n", usb_strerror ());
    }
  for(j=0;j<=0x1000;j++){
    printf("%x\n",r1val[j]);
  }
  
  return 0;
}




void
Write_Register (int add, unsigned char *buf, int
count,
                usb_dev_handle * handle)
{
  int rc;
  rc = usb_bulk_write (handle, add, buf, count, 1000);
 //set pci to read
  if (rc < 0)
    {
      printf ("%s\n", usb_strerror ());
    }
}



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