iusbprocesscommand.c

How to control USB interface under SZ platform

// This routine is called by the interrupt handler (triggered by the IN endpoint).
// It handles commands from the USB host 

#include "usb_pptt.h"
#include "usb_pdef.h"
#include "usb_pvar.h"

U8      _gUsbDrvNum;            // drive number (either 0 or 1)
U16     _gUsbSectorBuf[256];    // buffer for sector data
P_U16   _gpUsbBufPtr;           // pointer to buffer data
U8      _gUsbNumSector;         // number of sector to read/write
U16     _gUsbCurSector;         // current sector being read/write
U8      _gUsbPacketCount;       // USB packet count
U8      _gUsbDataToHost;        // flag indicating whether data is to be sent to host
                                
// The following 512 bytes of data seems to be some kind of configuration data
// for the card reader (or of the card being read).
// It's just reverse-engineered from the USB traffic.
// No information of what it mean.
const U16 _gUsbDrvParam[256] = {
    0x8000,0xF401,0x0000,0x0400,0x0000,0x0000,0x1000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0002,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x007D,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 

    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000, 
    0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000
    };
    
void _iUsbProcessCommand()
{
    U16 command[4];
    U8  i;
    EVENT   wakeupEvent;
    
    _gUsbDataToHost = FALSE;

    /* get command from endpoint FIFO */
    for (i=0; i<4; i++)
    {
        command[i] = _reg_USB_EP3_FDAT;
    }

    /* extract start sector and number of sectors */    
    _gUsbCurSector = ((command[1] & 0xFF) << 8) | ((command[1] >> 8) & 0xFF);
    _gUsbNumSector = command[0] & 0xFF;
    _gUsbDrvNum = (((U8) command[2]) >> 4) & 1;
    command[2] &= 0xFFEF;
        
    /* handle various commands */
    if (command[2] == 0x00A0)    // i.e. read drive parameters
    {
        if (_gUsbDrvStatus[_gUsbDrvNum] == USB_DRV_NOT_READY)
        {
            _reg_USB_EP4_FCTRL |= 0x20000000;
            _reg_USB_EP4_FDAT = 0xFF04; // drive not ready
        }
        else    // i.e. status == USB_DRV_READY
        {
            if ((*((_gUsbCallbacks->Drv[_gUsbDrvNum]).driveStatus))() ==
                USB_DRV_NOT_READY)
            {
                _reg_USB_EP4_FCTRL |= 0x20000000;
                _reg_USB_EP4_FDAT = 0xFF04; // drive not ready
            }
            else
            {
                // This command read the parameter of the disk.
                // We'll map the buffer pointer to the parameter block.
                // And then, we pretend that it is a ordinally file system read
                // operation to return the data requested
                _gUsbNumSector = 0;     // no need to read from disk
                // set buffer pointer to parameter block
                _gpUsbBufPtr = (P_U16)&_gUsbDrvParam;
                // change command to pretend that it's a read sector command
                command[2] = 0x00E0;
                command[3] = 0x2001;
            }
        }
    }

    if (command[2] == 0x00E0)    // i.e. disk read/write
    {
        if (_gUsbMode == USB_USE_INTR_ONLY)
        {
            if (command[3] == 0x2001)       // i.e. read operation */
            {
                if (_gUsbNumSector > 0)
                {
                   _iUsbReadSector();
                }
                // write first 2 packets to FIFO
                for (i=0; i<31; i++)
                {
                    _reg_USB_EP4_FDAT = *(_gpUsbBufPtr++);
                }
                _reg_USB_EP4_FCTRL |= 0x20000000;   // next write is last one in packet
                _reg_USB_EP4_FDAT = *(_gpUsbBufPtr++);

                for (i=0; i<31; i++)
                {
                    _reg_USB_EP4_FDAT = *(_gpUsbBufPtr++);;
                }
                _reg_USB_EP4_FCTRL |= 0x20000000;   // next write is last one in packet
                _reg_USB_EP4_FDAT = *(_gpUsbBufPtr++);

                _gUsbPacketCount = 2;   // count #packets copied to FIFO
                _gUsbDataToHost = TRUE;
            }
            else    // write operation (i.e. 0x3001)
            {
                // initialize variable to get ready for data from host
                // interrupt will then be generated to receive data
                _gUsbPacketCount = 0;
                _gpUsbBufPtr = (P_U16)&_gUsbSectorBuf;
            }            
        }
    }
}