Usb.cpp

Go to the documentation of this file.

/* Copyright (C) 2011 Circuits At Home, LTD. All rights reserved.

This software may be distributed and modified under the terms of the GNU
General Public License version 2 (GPL2) as published by the Free Software
Foundation and appearing in the file GPL2.TXT included in the packaging of
this file. Please note that GPL2 Section 2[b] requires that all works based
on this software must also be made publicly available under the terms of
the GPL2 ("Copyleft").

Contact information
-------------------

Circuits At Home, LTD
Web      :  http://www.circuitsathome.com
e-mail   :  support@circuitsathome.com
 */
/* USB functions */

#include "avrpins.h"
#include "max3421e.h"
#include "usbhost.h"
#include "Usb.h"

#if defined(ARDUINO) && ARDUINO >=100
#include "Arduino.h"
#else
#include <WProgram.h>
#endif

static uint8_t usb_error = 0;
static uint8_t usb_task_state;

/* constructor */
USB::USB() : bmHubPre(0) {
        usb_task_state = USB_DETACHED_SUBSTATE_INITIALIZE; //set up state machine
        init();
}

/* Initialize data structures */
void USB::init() {
        //devConfigIndex = 0;
        bmHubPre = 0;
}

uint8_t USB::getUsbTaskState(void) {
        return ( usb_task_state);
}

void USB::setUsbTaskState(uint8_t state) {
        usb_task_state = state;
}

EpInfo* USB::getEpInfoEntry(uint8_t addr, uint8_t ep) {
        UsbDevice *p = addrPool.GetUsbDevicePtr(addr);

        if (!p || !p->epinfo)
                return NULL;

        EpInfo *pep = p->epinfo;

        for (uint8_t i = 0; i < p->epcount; i++) {
                if ((pep)->epAddr == ep)
                        return pep;

                pep++;
        }
        return NULL;
}

/* set device table entry */

/* each device is different and has different number of endpoints. This function plugs endpoint record structure, defined in application, to devtable */
uint8_t USB::setEpInfoEntry(uint8_t addr, uint8_t epcount, EpInfo* eprecord_ptr) {
        if (!eprecord_ptr)
                return USB_ERROR_INVALID_ARGUMENT;

        UsbDevice *p = addrPool.GetUsbDevicePtr(addr);

        if (!p)
                return USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL;

        p->address = addr;
        p->epinfo = eprecord_ptr;
        p->epcount = epcount;

        return 0;
}

uint8_t USB::SetAddress(uint8_t addr, uint8_t ep, EpInfo **ppep, uint16_t &nak_limit) {
        UsbDevice *p = addrPool.GetUsbDevicePtr(addr);

        if (!p)
                return USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL;

        if (!p->epinfo)
                return USB_ERROR_EPINFO_IS_NULL;

        *ppep = getEpInfoEntry(addr, ep);

        if (!*ppep)
                return USB_ERROR_EP_NOT_FOUND_IN_TBL;

        nak_limit = (0x0001UL << (((*ppep)->bmNakPower > USB_NAK_MAX_POWER) ? USB_NAK_MAX_POWER : (*ppep)->bmNakPower));
        nak_limit--;
        /*
          USBTRACE2("\r\nAddress: ", addr);
          USBTRACE2(" EP: ", ep);
          USBTRACE2(" NAK Power: ",(*ppep)->bmNakPower);
          USBTRACE2(" NAK Limit: ", nak_limit);
          USBTRACE("\r\n");
         */
        regWr(rPERADDR, addr); //set peripheral address

        uint8_t mode = regRd(rMODE);

        //Serial.print("\r\nMode: ");
        //Serial.println( mode, HEX);
        //Serial.print("\r\nLS: ");
        //Serial.println(p->lowspeed, HEX);



        // Set bmLOWSPEED and bmHUBPRE in case of low-speed device, reset them otherwise
        regWr(rMODE, (p->lowspeed) ? mode | bmLOWSPEED | bmHubPre : mode & ~(bmHUBPRE | bmLOWSPEED));

        return 0;
}

/* Control transfer. Sets address, endpoint, fills control packet with necessary data, dispatches control packet, and initiates bulk IN transfer,   */
/* depending on request. Actual requests are defined as inlines                                                                                      */
/* return codes:                */
/* 00       =   success         */

/* 01-0f    =   non-zero HRSLT  */
uint8_t USB::ctrlReq(uint8_t addr, uint8_t ep, uint8_t bmReqType, uint8_t bRequest, uint8_t wValLo, uint8_t wValHi,
        uint16_t wInd, uint16_t total, uint16_t nbytes, uint8_t* dataptr, USBReadParser *p) {
        bool direction = false; //request direction, IN or OUT
        uint8_t rcode;
        SETUP_PKT setup_pkt;

        EpInfo *pep = NULL;
        uint16_t nak_limit = 0;

        rcode = SetAddress(addr, ep, &pep, nak_limit);

        if (rcode)
                return rcode;

        direction = ((bmReqType & 0x80) > 0);

        /* fill in setup packet */
        setup_pkt.ReqType_u.bmRequestType = bmReqType;
        setup_pkt.bRequest = bRequest;
        setup_pkt.wVal_u.wValueLo = wValLo;
        setup_pkt.wVal_u.wValueHi = wValHi;
        setup_pkt.wIndex = wInd;
        setup_pkt.wLength = total;

        bytesWr(rSUDFIFO, 8, (uint8_t*) & setup_pkt); //transfer to setup packet FIFO

        rcode = dispatchPkt(tokSETUP, ep, nak_limit); //dispatch packet

        if (rcode) //return HRSLT if not zero
                return ( rcode);

        if (dataptr != NULL) //data stage, if present
        {
                if (direction) //IN transfer
                {
                        uint16_t left = total;

                        pep->bmRcvToggle = 1; //bmRCVTOG1;

                        while (left) {
                                // Bytes read into buffer
                                uint16_t read = nbytes;
                                //uint16_t read = (left<nbytes) ? left : nbytes;

                                rcode = InTransfer(pep, nak_limit, &read, dataptr);
                                if (rcode == hrTOGERR) {
                                        // yes, we flip it wrong here so that next time it is actually correct!
                                        pep->bmRcvToggle = (regRd(rHRSL) & bmSNDTOGRD) ? 0 : 1;
                                        continue;
                                }

                                if (rcode)
                                        return rcode;

                                // Invoke callback function if inTransfer completed successfully and callback function pointer is specified
                                if (!rcode && p)
                                        ((USBReadParser*)p)->Parse(read, dataptr, total - left);

                                left -= read;

                                if (read < nbytes)
                                        break;
                        }
                } else //OUT transfer
                {
                        pep->bmSndToggle = 1; //bmSNDTOG1;
                        rcode = OutTransfer(pep, nak_limit, nbytes, dataptr);
                }
                if (rcode) //return error
                        return ( rcode);
        }
        // Status stage
        return dispatchPkt((direction) ? tokOUTHS : tokINHS, ep, nak_limit); //GET if direction
}

/* IN transfer to arbitrary endpoint. Assumes PERADDR is set. Handles multiple packets if necessary. Transfers 'nbytes' bytes. */
/* Keep sending INs and writes data to memory area pointed by 'data'                                                           */

/* rcode 0 if no errors. rcode 01-0f is relayed from dispatchPkt(). Rcode f0 means RCVDAVIRQ error,
            fe USB xfer timeout */
uint8_t USB::inTransfer(uint8_t addr, uint8_t ep, uint16_t *nbytesptr, uint8_t* data) {
        EpInfo *pep = NULL;
        uint16_t nak_limit = 0;

        uint8_t rcode = SetAddress(addr, ep, &pep, nak_limit);

        if (rcode) {
                //printf("SetAddress Failed");
                return rcode;
        }
        return InTransfer(pep, nak_limit, nbytesptr, data);
}

uint8_t USB::InTransfer(EpInfo *pep, uint16_t nak_limit, uint16_t *nbytesptr, uint8_t* data) {
        uint8_t rcode = 0;
        uint8_t pktsize;

        uint16_t nbytes = *nbytesptr;
        //printf("Requesting %i bytes ", nbytes);
        uint8_t maxpktsize = pep->maxPktSize;

        *nbytesptr = 0;
        regWr(rHCTL, (pep->bmRcvToggle) ? bmRCVTOG1 : bmRCVTOG0); //set toggle value

        while (1) // use a 'return' to exit this loop
        {
                rcode = dispatchPkt(tokIN, pep->epAddr, nak_limit); //IN packet to EP-'endpoint'. Function takes care of NAKS.
                if (rcode == hrTOGERR) {
                        // yes, we flip it wrong here so that next time it is actually correct!
                        pep->bmRcvToggle = (regRd(rHRSL) & bmSNDTOGRD) ? 0 : 1;
                        regWr(rHCTL, (pep->bmRcvToggle) ? bmRCVTOG1 : bmRCVTOG0); //set toggle value
                        continue;
                }
                if (rcode) {
                        //printf(">>>>>>>> Problem! dispatchPkt %2.2x\r\n", rcode);
                        break; //should be 0, indicating ACK. Else return error code.
                }
                /* check for RCVDAVIRQ and generate error if not present */
                /* the only case when absence of RCVDAVIRQ makes sense is when toggle error occurred. Need to add handling for that */
                if ((regRd(rHIRQ) & bmRCVDAVIRQ) == 0) {
                        //printf(">>>>>>>> Problem! NO RCVDAVIRQ!\r\n");
                        rcode = 0xf0; //receive error
                        break;
                }
                pktsize = regRd(rRCVBC); //number of received bytes
                //printf("Got %i bytes \r\n", pktsize);
                // This would be OK, but...
                //assert(pktsize <= nbytes);
                if (pktsize > nbytes) {
                        // This can happen. Use of assert on Arduino locks up the Arduino.
                        // So I will trim the value, and hope for the best.
                        //printf(">>>>>>>> Problem! Wanted %i bytes but got %i.\r\n", nbytes, pktsize);
                        pktsize = nbytes;
                }

                int16_t mem_left = (int16_t)nbytes - *((int16_t*)nbytesptr);

                if (mem_left < 0)
                        mem_left = 0;

                data = bytesRd(rRCVFIFO, ((pktsize > mem_left) ? mem_left : pktsize), data);

                regWr(rHIRQ, bmRCVDAVIRQ); // Clear the IRQ & free the buffer
                *nbytesptr += pktsize; // add this packet's byte count to total transfer length

                /* The transfer is complete under two conditions:           */
                /* 1. The device sent a short packet (L.T. maxPacketSize)   */
                /* 2. 'nbytes' have been transferred.                       */
                if ((pktsize < maxpktsize) || (*nbytesptr >= nbytes)) // have we transferred 'nbytes' bytes?
                {
                        // Save toggle value
                        pep->bmRcvToggle = ((regRd(rHRSL) & bmRCVTOGRD)) ? 1 : 0;
                        //printf("\r\n");
                        rcode = 0;
                        break;
                } // if
        } //while( 1 )
        return ( rcode);
}

/* OUT transfer to arbitrary endpoint. Handles multiple packets if necessary. Transfers 'nbytes' bytes. */
/* Handles NAK bug per Maxim Application Note 4000 for single buffer transfer   */

/* rcode 0 if no errors. rcode 01-0f is relayed from HRSL                       */
uint8_t USB::outTransfer(uint8_t addr, uint8_t ep, uint16_t nbytes, uint8_t* data) {
        EpInfo *pep = NULL;
        uint16_t nak_limit = 0;

        uint8_t rcode = SetAddress(addr, ep, &pep, nak_limit);

        if (rcode)
                return rcode;

        return OutTransfer(pep, nak_limit, nbytes, data);
}

uint8_t USB::OutTransfer(EpInfo *pep, uint16_t nak_limit, uint16_t nbytes, uint8_t *data) {
        uint8_t rcode = hrSUCCESS, retry_count;
        uint8_t *data_p = data; //local copy of the data pointer
        uint16_t bytes_tosend, nak_count;
        uint16_t bytes_left = nbytes;

        uint8_t maxpktsize = pep->maxPktSize;

        if (maxpktsize < 1 || maxpktsize > 64)
                return USB_ERROR_INVALID_MAX_PKT_SIZE;

        unsigned long timeout = millis() + USB_XFER_TIMEOUT;

        regWr(rHCTL, (pep->bmSndToggle) ? bmSNDTOG1 : bmSNDTOG0); //set toggle value

        while (bytes_left) {
                retry_count = 0;
                nak_count = 0;
                bytes_tosend = (bytes_left >= maxpktsize) ? maxpktsize : bytes_left;
                bytesWr(rSNDFIFO, bytes_tosend, data_p); //filling output FIFO
                regWr(rSNDBC, bytes_tosend); //set number of bytes
                regWr(rHXFR, (tokOUT | pep->epAddr)); //dispatch packet
                while (!(regRd(rHIRQ) & bmHXFRDNIRQ)); //wait for the completion IRQ
                regWr(rHIRQ, bmHXFRDNIRQ); //clear IRQ
                rcode = (regRd(rHRSL) & 0x0f);

                while (rcode && (timeout > millis())) {
                        switch (rcode) {
                                case hrNAK:
                                        nak_count++;
                                        if (nak_limit && (nak_count == nak_limit))
                                                goto breakout;
                                        //return ( rcode);
                                        break;
                                case hrTIMEOUT:
                                        retry_count++;
                                        if (retry_count == USB_RETRY_LIMIT)
                                                goto breakout;
                                        //return ( rcode);
                                        break;
                                case hrTOGERR:
                                        // yes, we flip it wrong here so that next time it is actually correct!
                                        pep->bmSndToggle = (regRd(rHRSL) & bmSNDTOGRD) ? 0 : 1;
                                        regWr(rHCTL, (pep->bmSndToggle) ? bmSNDTOG1 : bmSNDTOG0); //set toggle value
                                        break;
                                default:
                                        goto breakout;
                        }//switch( rcode

                        /* process NAK according to Host out NAK bug */
                        regWr(rSNDBC, 0);
                        regWr(rSNDFIFO, *data_p);
                        regWr(rSNDBC, bytes_tosend);
                        regWr(rHXFR, (tokOUT | pep->epAddr)); //dispatch packet
                        while (!(regRd(rHIRQ) & bmHXFRDNIRQ)); //wait for the completion IRQ
                        regWr(rHIRQ, bmHXFRDNIRQ); //clear IRQ
                        rcode = (regRd(rHRSL) & 0x0f);
                }//while( rcode && ....
                bytes_left -= bytes_tosend;
                data_p += bytes_tosend;
        }//while( bytes_left...
breakout:

        pep->bmSndToggle = (regRd(rHRSL) & bmSNDTOGRD) ? 1 : 0; //bmSNDTOG1 : bmSNDTOG0;  //update toggle
        return ( rcode); //should be 0 in all cases
}
/* dispatch USB packet. Assumes peripheral address is set and relevant buffer is loaded/empty       */
/* If NAK, tries to re-send up to nak_limit times                                                   */
/* If nak_limit == 0, do not count NAKs, exit after timeout                                         */
/* If bus timeout, re-sends up to USB_RETRY_LIMIT times                                             */

/* return codes 0x00-0x0f are HRSLT( 0x00 being success ), 0xff means timeout                       */
uint8_t USB::dispatchPkt(uint8_t token, uint8_t ep, uint16_t nak_limit) {
        unsigned long timeout = millis() + USB_XFER_TIMEOUT;
        uint8_t tmpdata;
        uint8_t rcode = hrSUCCESS;
        uint8_t retry_count = 0;
        uint16_t nak_count = 0;

        while (timeout > millis()) {
                regWr(rHXFR, (token | ep)); //launch the transfer
                rcode = USB_ERROR_TRANSFER_TIMEOUT;

                while (timeout > millis()) //wait for transfer completion
                {
                        tmpdata = regRd(rHIRQ);

                        if (tmpdata & bmHXFRDNIRQ) {
                                regWr(rHIRQ, bmHXFRDNIRQ); //clear the interrupt
                                rcode = 0x00;
                                break;
                        }//if( tmpdata & bmHXFRDNIRQ

                }//while ( millis() < timeout

                //if (rcode != 0x00) //exit if timeout
                //        return ( rcode);

                rcode = (regRd(rHRSL) & 0x0f); //analyze transfer result

                switch (rcode) {
                        case hrNAK:
                                nak_count++;
                                if (nak_limit && (nak_count == nak_limit))
                                        return (rcode);
                                break;
                        case hrTIMEOUT:
                                retry_count++;
                                if (retry_count == USB_RETRY_LIMIT)
                                        return (rcode);
                                break;
                        default:
                                return (rcode);
                }//switch( rcode

        }//while( timeout > millis()
        return ( rcode);
}

/* USB main task. Performs enumeration/cleanup */
void USB::Task(void) //USB state machine
{
        uint8_t rcode;
        uint8_t tmpdata;
        static unsigned long delay = 0;
        //USB_DEVICE_DESCRIPTOR buf;
        bool lowspeed = false;

        MAX3421E::Task();

        tmpdata = getVbusState();

        /* modify USB task state if Vbus changed */
        switch (tmpdata) {
                case SE1: //illegal state
                        usb_task_state = USB_DETACHED_SUBSTATE_ILLEGAL;
                        lowspeed = false;
                        break;
                case SE0: //disconnected
                        if ((usb_task_state & USB_STATE_MASK) != USB_STATE_DETACHED)
                                usb_task_state = USB_DETACHED_SUBSTATE_INITIALIZE;
                        lowspeed = false;
                        break;
                case LSHOST:
                
                        lowspeed = true;
                                //intentional fallthrough
                case FSHOST: //attached
                        if ((usb_task_state & USB_STATE_MASK) == USB_STATE_DETACHED) {
                                delay = millis() + USB_SETTLE_DELAY;
                                usb_task_state = USB_ATTACHED_SUBSTATE_SETTLE;
                        }
                        break;
        }// switch( tmpdata

        for (uint8_t i = 0; i < USB_NUMDEVICES; i++)
                if (devConfig[i])
                        rcode = devConfig[i]->Poll();

        switch (usb_task_state) {
                case USB_DETACHED_SUBSTATE_INITIALIZE:
                        init();

                        for (uint8_t i = 0; i < USB_NUMDEVICES; i++)
                                if (devConfig[i])
                                        rcode = devConfig[i]->Release();

                        usb_task_state = USB_DETACHED_SUBSTATE_WAIT_FOR_DEVICE;
                        break;
                case USB_DETACHED_SUBSTATE_WAIT_FOR_DEVICE: //just sit here
                        break;
                case USB_DETACHED_SUBSTATE_ILLEGAL: //just sit here
                        break;
                case USB_ATTACHED_SUBSTATE_SETTLE: //settle time for just attached device
                        if (delay < millis())
                                usb_task_state = USB_ATTACHED_SUBSTATE_RESET_DEVICE;
                        break;
                case USB_ATTACHED_SUBSTATE_RESET_DEVICE:
                        regWr(rHCTL, bmBUSRST); //issue bus reset
                        usb_task_state = USB_ATTACHED_SUBSTATE_WAIT_RESET_COMPLETE;
                        break;
                case USB_ATTACHED_SUBSTATE_WAIT_RESET_COMPLETE:
                        if ((regRd(rHCTL) & bmBUSRST) == 0) {
                                tmpdata = regRd(rMODE) | bmSOFKAENAB; //start SOF generation
                                regWr(rMODE, tmpdata);
                                usb_task_state = USB_ATTACHED_SUBSTATE_WAIT_SOF;
                                //delay = millis() + 20; //20ms wait after reset per USB spec
                        }
                        break;
                case USB_ATTACHED_SUBSTATE_WAIT_SOF: //todo: change check order
                        if (regRd(rHIRQ) & bmFRAMEIRQ) {
                                //when first SOF received _and_ 20ms has passed we can continue
                                /*
                                if (delay < millis()) //20ms passed
                                        usb_task_state = USB_STATE_CONFIGURING;
                                 */
                                usb_task_state = USB_ATTACHED_SUBSTATE_WAIT_RESET;
                                delay = millis() + 20;
                        }
                        break;
                case USB_ATTACHED_SUBSTATE_WAIT_RESET:
                        if (delay < millis()) usb_task_state = USB_STATE_CONFIGURING;
                        break;
                case USB_STATE_CONFIGURING:

                                //Serial.print("\r\nConf.LS: ");
                                //Serial.println(lowspeed, HEX);

                        rcode = Configuring(0, 0, lowspeed);

                        if (rcode) {
                                if (rcode != USB_DEV_CONFIG_ERROR_DEVICE_INIT_INCOMPLETE) {
                                        usb_error = rcode;
                                        usb_task_state = USB_STATE_ERROR;
                                }
                        } else
                                usb_task_state = USB_STATE_RUNNING;
                        break;
                case USB_STATE_RUNNING:
                        break;
                case USB_STATE_ERROR:
                        //MAX3421E::Init();
                        break;
        } // switch( usb_task_state )
}

uint8_t USB::DefaultAddressing(uint8_t parent, uint8_t port, bool lowspeed) {
        //uint8_t       buf[12];
        uint8_t rcode;
        UsbDevice *p0 = NULL, *p = NULL;

        // Get pointer to pseudo device with address 0 assigned
        p0 = addrPool.GetUsbDevicePtr(0);

        if (!p0)
                return USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL;

        if (!p0->epinfo)
                return USB_ERROR_EPINFO_IS_NULL;

        p0->lowspeed = (lowspeed) ? true : false;

        // Allocate new address according to device class
        uint8_t bAddress = addrPool.AllocAddress(parent, false, port);

        if (!bAddress)
                return USB_ERROR_OUT_OF_ADDRESS_SPACE_IN_POOL;

        p = addrPool.GetUsbDevicePtr(bAddress);

        if (!p)
                return USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL;

        p->lowspeed = lowspeed;

        // Assign new address to the device
        rcode = setAddr(0, 0, bAddress);

        if (rcode) {
                addrPool.FreeAddress(bAddress);
                bAddress = 0;
                return rcode;
        }
        return 0;
};

uint8_t USB::AttemptConfig(uint8_t driver, uint8_t parent, uint8_t port, bool lowspeed) {
        uint8_t rcode = 0;
        //printf("AttemptConfig: parent = %i, port = %i\r\n", parent, port);

        rcode = devConfig[driver]->ConfigureDevice(parent, port, lowspeed);
        if (rcode == USB_ERROR_CONFIG_REQUIRES_ADDITIONAL_RESET) {
                if (parent == 0) {
                        // Send a bus reset on the root interface.
                        regWr(rHCTL, bmBUSRST); //issue bus reset
                        delay(102); // delay 102ms, compensate for clock inaccuracy.
                } else {
                        // reset parent port
                        devConfig[parent]->ResetHubPort(port);
                }
        }
        rcode = devConfig[driver]->Init(parent, port, lowspeed);
        return rcode;
}

/*
 * This is broken. We need to enumerate differently.
 * It causes major problems with several devices if detected in an unexpected order.
 *
 *
 * Oleg - I wouldn't do anything before the newly connected device is considered sane.
 * i.e.(delays are not indicated for brevity):
 * 1. reset
 * 2. GetDevDescr();
 * 3a. If ACK, continue with allocating address, addressing, etc.
 * 3b. Else reset again, count resets, stop at some number (5?).
 * 4. When max.number of resets is reached, toggle power/fail
 * If desired, this could be modified by performing two resets with GetDevDescr() in the middle - however, from my experience, if a device answers to GDD()
 * it doesn't need to be reset again
 * New steps proposal:
 * 1: get address pool instance. exit on fail
 * 2: pUsb->getDevDescr(0, 0, constBufSize, (uint8_t*)buf). exit on fail.
 * 3: bus reset, 100ms delay
 * 4: set address
 * 5: pUsb->setEpInfoEntry(bAddress, 1, epInfo), exit on fail
 * 6: while (configurations) {
 *              for(each configuration) {
 *                      for (each driver) {
 *                              6a: Ask device if it likes configuration. Returns 0 on OK.
 *                                      If successful, the driver configured device.
 *                                      The driver now owns the endpoints, and takes over managing them.
 *                                      The following will need codes:
 *                                          Everything went well, instance consumed, exit with success.
 *                                          Instance already in use, ignore it, try next driver.
 *                                          Not a supported device, ignore it, try next driver.
 *                                          Not a supported configuration for this device, ignore it, try next driver.
 *                                          Could not configure device, fatal, exit with fail.
 *                      }
 *              }
 *    }
 * 7: for(each driver) {
 *      7a: Ask device if it knows this VID/PID. Acts exactly like 6a, but using VID/PID
 * 8: if we get here, no driver likes the device plugged in, so exit failure.
 *
 */
uint8_t USB::Configuring(uint8_t parent, uint8_t port, bool lowspeed) {
        //uint8_t bAddress = 0;
        //printf("Configuring: parent = %i, port = %i\r\n", parent, port);
        uint8_t devConfigIndex;
        uint8_t rcode = 0;
        uint8_t buf[sizeof (USB_DEVICE_DESCRIPTOR)];
        UsbDevice *p = NULL;
        EpInfo *oldep_ptr = NULL;
        EpInfo epInfo;

        epInfo.epAddr = 0;
        epInfo.maxPktSize = 8;
        epInfo.epAttribs = 0;
        epInfo.bmNakPower = USB_NAK_MAX_POWER;

        delay(2000);
        AddressPool &addrPool = GetAddressPool();
        // Get pointer to pseudo device with address 0 assigned
        p = addrPool.GetUsbDevicePtr(0);
        if (!p) {
                //printf("Configuring error: USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL\r\n");
                return USB_ERROR_ADDRESS_NOT_FOUND_IN_POOL;
        }

        // Save old pointer to EP_RECORD of address 0
        oldep_ptr = p->epinfo;

        // Temporary assign new pointer to epInfo to p->epinfo in order to
        // avoid toggle inconsistence

        p->epinfo = &epInfo;

        p->lowspeed = lowspeed;
        // Get device descriptor
        rcode = getDevDescr(0, 0, sizeof (USB_DEVICE_DESCRIPTOR), (uint8_t*)buf);

        // Restore p->epinfo
        p->epinfo = oldep_ptr;

        if (rcode) {
                //printf("Configuring error: Can't get USB_DEVICE_DESCRIPTOR\r\n");
                return rcode;
        }

        // to-do?
        // Allocate new address according to device class
        //bAddress = addrPool.AllocAddress(parent, false, port);

        //if (!bAddress)
        //        return USB_ERROR_OUT_OF_ADDRESS_SPACE_IN_POOL;

        uint16_t vid = (uint16_t)((USB_DEVICE_DESCRIPTOR*)buf)->idVendor;
        uint16_t pid = (uint16_t)((USB_DEVICE_DESCRIPTOR*)buf)->idProduct;
        uint8_t klass = ((USB_DEVICE_DESCRIPTOR*)buf)->bDeviceClass;

        // Attempt to configure if VID/PID or device class matches with a driver
        for (devConfigIndex = 0; devConfigIndex < USB_NUMDEVICES; devConfigIndex++) {
                if (!devConfig[devConfigIndex]) continue; // no driver
                if (devConfig[devConfigIndex]->GetAddress()) continue; // consumed
                if (devConfig[devConfigIndex]->VIDPIDOK(vid, pid) || devConfig[devConfigIndex]->DEVCLASSOK(klass)) {
                        rcode = AttemptConfig(devConfigIndex, parent, port, lowspeed);
                        if (rcode != USB_DEV_CONFIG_ERROR_DEVICE_NOT_SUPPORTED)
                                break;
                }
        }

        if (devConfigIndex < USB_NUMDEVICES) {
                return rcode;
        }


        // blindly attempt to configure
        for (devConfigIndex = 0; devConfigIndex < USB_NUMDEVICES; devConfigIndex++) {
                if (!devConfig[devConfigIndex]) continue;
                if (devConfig[devConfigIndex]->GetAddress()) continue; // consumed
                if (devConfig[devConfigIndex]->VIDPIDOK(vid, pid) || devConfig[devConfigIndex]->DEVCLASSOK(klass)) continue; // If this is true it means it must have returned USB_DEV_CONFIG_ERROR_DEVICE_NOT_SUPPORTED above
                rcode = AttemptConfig(devConfigIndex, parent, port, lowspeed);

                //printf("ERROR ENUMERATING %2.2x\r\n", rcode);
                if (!(rcode == USB_DEV_CONFIG_ERROR_DEVICE_NOT_SUPPORTED || rcode == USB_ERROR_CLASS_INSTANCE_ALREADY_IN_USE)) {
                        // in case of an error dev_index should be reset to 0
                        //      in order to start from the very beginning the
                        //      next time the program gets here
                        //if (rcode != USB_DEV_CONFIG_ERROR_DEVICE_INIT_INCOMPLETE)
                        //        devConfigIndex = 0;
                        return rcode;
                }
        }
        // if we get here that means that the device class is not supported by any of registered classes
        rcode = DefaultAddressing(parent, port, lowspeed);

        return rcode;
}

uint8_t USB::ReleaseDevice(uint8_t addr) {
        if (!addr)
                return 0;

        for (uint8_t i = 0; i < USB_NUMDEVICES; i++) {
                if(!devConfig[i]) continue;
                if (devConfig[i]->GetAddress() == addr)
                        return devConfig[i]->Release();
        }
        return 0;
}

#if 1 
//get device descriptor

uint8_t USB::getDevDescr(uint8_t addr, uint8_t ep, uint16_t nbytes, uint8_t* dataptr) {
        return ( ctrlReq(addr, ep, bmREQ_GET_DESCR, USB_REQUEST_GET_DESCRIPTOR, 0x00, USB_DESCRIPTOR_DEVICE, 0x0000, nbytes, nbytes, dataptr, NULL));
}
//get configuration descriptor

uint8_t USB::getConfDescr(uint8_t addr, uint8_t ep, uint16_t nbytes, uint8_t conf, uint8_t* dataptr) {
        return ( ctrlReq(addr, ep, bmREQ_GET_DESCR, USB_REQUEST_GET_DESCRIPTOR, conf, USB_DESCRIPTOR_CONFIGURATION, 0x0000, nbytes, nbytes, dataptr, NULL));
}

uint8_t USB::getConfDescr(uint8_t addr, uint8_t ep, uint8_t conf, USBReadParser *p) {
        const uint8_t bufSize = 64;
        uint8_t buf[bufSize];

        uint8_t ret = getConfDescr(addr, ep, 8, conf, buf);

        if (ret)
                return ret;

        uint16_t total = ((USB_CONFIGURATION_DESCRIPTOR*)buf)->wTotalLength;

        //USBTRACE2("\r\ntotal conf.size:", total);

        return ( ctrlReq(addr, ep, bmREQ_GET_DESCR, USB_REQUEST_GET_DESCRIPTOR, conf, USB_DESCRIPTOR_CONFIGURATION, 0x0000, total, bufSize, buf, p));
}

//get string descriptor

uint8_t USB::getStrDescr(uint8_t addr, uint8_t ep, uint16_t ns, uint8_t index, uint16_t langid, uint8_t* dataptr) {
        return ( ctrlReq(addr, ep, bmREQ_GET_DESCR, USB_REQUEST_GET_DESCRIPTOR, index, USB_DESCRIPTOR_STRING, langid, ns, ns, dataptr, NULL));
}
//set address

uint8_t USB::setAddr(uint8_t oldaddr, uint8_t ep, uint8_t newaddr) {
        return ( ctrlReq(oldaddr, ep, bmREQ_SET, USB_REQUEST_SET_ADDRESS, newaddr, 0x00, 0x0000, 0x0000, 0x0000, NULL, NULL));
}
//set configuration

uint8_t USB::setConf(uint8_t addr, uint8_t ep, uint8_t conf_value) {
        return ( ctrlReq(addr, ep, bmREQ_SET, USB_REQUEST_SET_CONFIGURATION, conf_value, 0x00, 0x0000, 0x0000, 0x0000, NULL, NULL));
}

#endif // defined(USB_METHODS_INLINE)