USB_Host_Shield_2.0/confdescparser.h

/* 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
 */
#if !defined(_usb_h_) || defined(__CONFDESCPARSER_H__)
#error "Never include confdescparser.h directly; include Usb.h instead"
#else

#define __CONFDESCPARSER_H__

class UsbConfigXtracter {
public:
        //virtual void ConfigXtract(const USB_CONFIGURATION_DESCRIPTOR *conf) = 0;
        //virtual void InterfaceXtract(uint8_t conf, const USB_INTERFACE_DESCRIPTOR *iface) = 0;

        virtual void EndpointXtract(uint8_t conf __attribute__((unused)), uint8_t iface __attribute__((unused)), uint8_t alt __attribute__((unused)), uint8_t proto __attribute__((unused)), const USB_ENDPOINT_DESCRIPTOR *ep __attribute__((unused))) {
        };
};

#define CP_MASK_COMPARE_CLASS                   1
#define CP_MASK_COMPARE_SUBCLASS                2
#define CP_MASK_COMPARE_PROTOCOL                4
#define CP_MASK_COMPARE_ALL                     7

// Configuration Descriptor Parser Class Template

template <const uint8_t CLASS_ID, const uint8_t SUBCLASS_ID, const uint8_t PROTOCOL_ID, const uint8_t MASK>
class ConfigDescParser : public USBReadParser {
        UsbConfigXtracter *theXtractor;
        MultiValueBuffer theBuffer;
        MultiByteValueParser valParser;
        ByteSkipper theSkipper;
        uint8_t varBuffer[16 /*sizeof(USB_CONFIGURATION_DESCRIPTOR)*/];

        uint8_t stateParseDescr; // ParseDescriptor state

        uint8_t dscrLen; // Descriptor length
        uint8_t dscrType; // Descriptor type

        bool isGoodInterface; // Apropriate interface flag
        uint8_t confValue; // Configuration value
        uint8_t protoValue; // Protocol value
        uint8_t ifaceNumber; // Interface number
        uint8_t ifaceAltSet; // Interface alternate settings

        bool UseOr;
        bool ParseDescriptor(uint8_t **pp, uint16_t *pcntdn);
        void PrintHidDescriptor(const USB_HID_DESCRIPTOR *pDesc);

public:

        void SetOR(void) {
                UseOr = true;
        }
        ConfigDescParser(UsbConfigXtracter *xtractor);
        void Parse(const uint16_t len, const uint8_t *pbuf, const uint16_t &offset);
};

template <const uint8_t CLASS_ID, const uint8_t SUBCLASS_ID, const uint8_t PROTOCOL_ID, const uint8_t MASK>
ConfigDescParser<CLASS_ID, SUBCLASS_ID, PROTOCOL_ID, MASK>::ConfigDescParser(UsbConfigXtracter *xtractor) :
theXtractor(xtractor),
stateParseDescr(0),
dscrLen(0),
dscrType(0),
UseOr(false) {
        theBuffer.pValue = varBuffer;
        valParser.Initialize(&theBuffer);
        theSkipper.Initialize(&theBuffer);
};

template <const uint8_t CLASS_ID, const uint8_t SUBCLASS_ID, const uint8_t PROTOCOL_ID, const uint8_t MASK>
void ConfigDescParser<CLASS_ID, SUBCLASS_ID, PROTOCOL_ID, MASK>::Parse(const uint16_t len, const uint8_t *pbuf, const uint16_t &offset __attribute__((unused))) {
        uint16_t cntdn = (uint16_t)len;
        uint8_t *p = (uint8_t*)pbuf;

        while(cntdn)
                if(!ParseDescriptor(&p, &cntdn))
                        return;
}

/* Parser for the configuration descriptor. Takes values for class, subclass, protocol fields in interface descriptor and
  compare masks for them. When the match is found, calls EndpointXtract passing buffer containing endpoint descriptor */
template <const uint8_t CLASS_ID, const uint8_t SUBCLASS_ID, const uint8_t PROTOCOL_ID, const uint8_t MASK>
bool ConfigDescParser<CLASS_ID, SUBCLASS_ID, PROTOCOL_ID, MASK>::ParseDescriptor(uint8_t **pp, uint16_t *pcntdn) {
        USB_CONFIGURATION_DESCRIPTOR* ucd = reinterpret_cast<USB_CONFIGURATION_DESCRIPTOR*>(varBuffer);
        USB_INTERFACE_DESCRIPTOR* uid = reinterpret_cast<USB_INTERFACE_DESCRIPTOR*>(varBuffer);
        switch(stateParseDescr) {
                case 0:
                        theBuffer.valueSize = 2;
                        valParser.Initialize(&theBuffer);
                        stateParseDescr = 1;
                case 1:
                        if(!valParser.Parse(pp, pcntdn))
                                return false;
                        dscrLen = *((uint8_t*)theBuffer.pValue);
                        dscrType = *((uint8_t*)theBuffer.pValue + 1);
                        stateParseDescr = 2;
                case 2:
                        // This is a sort of hack. Assuming that two bytes are all ready in the buffer
                        //      the pointer is positioned two bytes ahead in order for the rest of descriptor
                        //      to be read right after the size and the type fields.
                        // This should be used carefully. varBuffer should be used directly to handle data
                        //      in the buffer.
                        theBuffer.pValue = varBuffer + 2;
                        stateParseDescr = 3;
                case 3:
                        switch(dscrType) {
                                case USB_DESCRIPTOR_INTERFACE:
                                        isGoodInterface = false;
                                        break;
                                case USB_DESCRIPTOR_CONFIGURATION:
                                case USB_DESCRIPTOR_ENDPOINT:
                                case HID_DESCRIPTOR_HID:
                                        break;
                        }
                        theBuffer.valueSize = dscrLen - 2;
                        valParser.Initialize(&theBuffer);
                        stateParseDescr = 4;
                case 4:
                        switch(dscrType) {
                                case USB_DESCRIPTOR_CONFIGURATION:
                                        if(!valParser.Parse(pp, pcntdn))
                                                return false;
                                        confValue = ucd->bConfigurationValue;
                                        break;
                                case USB_DESCRIPTOR_INTERFACE:
                                        if(!valParser.Parse(pp, pcntdn))
                                                return false;
                                        if((MASK & CP_MASK_COMPARE_CLASS) && uid->bInterfaceClass != CLASS_ID)
                                                break;
                                        if((MASK & CP_MASK_COMPARE_SUBCLASS) && uid->bInterfaceSubClass != SUBCLASS_ID)
                                                break;
                                        if(UseOr) {
                                                if((!((MASK & CP_MASK_COMPARE_PROTOCOL) && uid->bInterfaceProtocol)))
                                                        break;
                                        } else {
                                                if((MASK & CP_MASK_COMPARE_PROTOCOL) && uid->bInterfaceProtocol != PROTOCOL_ID)
                                                        break;
                                        }
                                        isGoodInterface = true;
                                        ifaceNumber = uid->bInterfaceNumber;
                                        ifaceAltSet = uid->bAlternateSetting;
                                        protoValue = uid->bInterfaceProtocol;
                                        break;
                                case USB_DESCRIPTOR_ENDPOINT:
                                        if(!valParser.Parse(pp, pcntdn))
                                                return false;
                                        if(isGoodInterface)
                                                if(theXtractor)
                                                        theXtractor->EndpointXtract(confValue, ifaceNumber, ifaceAltSet, protoValue, (USB_ENDPOINT_DESCRIPTOR*)varBuffer);
                                        break;
                                        //case HID_DESCRIPTOR_HID:
                                        //      if (!valParser.Parse(pp, pcntdn))
                                        //              return false;
                                        //      PrintHidDescriptor((const USB_HID_DESCRIPTOR*)varBuffer);
                                        //      break;
                                default:
                                        if(!theSkipper.Skip(pp, pcntdn, dscrLen - 2))
                                                return false;
                        }
                        theBuffer.pValue = varBuffer;
                        stateParseDescr = 0;
        }
        return true;
}

template <const uint8_t CLASS_ID, const uint8_t SUBCLASS_ID, const uint8_t PROTOCOL_ID, const uint8_t MASK>
void ConfigDescParser<CLASS_ID, SUBCLASS_ID, PROTOCOL_ID, MASK>::PrintHidDescriptor(const USB_HID_DESCRIPTOR *pDesc) {
        Notify(PSTR("\r\n\r\nHID Descriptor:\r\n"), 0x80);
        Notify(PSTR("bDescLength:\t\t"), 0x80);
        PrintHex<uint8_t > (pDesc->bLength, 0x80);

        Notify(PSTR("\r\nbDescriptorType:\t"), 0x80);
        PrintHex<uint8_t > (pDesc->bDescriptorType, 0x80);

        Notify(PSTR("\r\nbcdHID:\t\t\t"), 0x80);
        PrintHex<uint16_t > (pDesc->bcdHID, 0x80);

        Notify(PSTR("\r\nbCountryCode:\t\t"), 0x80);
        PrintHex<uint8_t > (pDesc->bCountryCode, 0x80);

        Notify(PSTR("\r\nbNumDescriptors:\t"), 0x80);
        PrintHex<uint8_t > (pDesc->bNumDescriptors, 0x80);

        for(uint8_t i = 0; i < pDesc->bNumDescriptors; i++) {
                HID_CLASS_DESCRIPTOR_LEN_AND_TYPE *pLT = (HID_CLASS_DESCRIPTOR_LEN_AND_TYPE*)&(pDesc->bDescrType);

                Notify(PSTR("\r\nbDescrType:\t\t"), 0x80);
                PrintHex<uint8_t > (pLT[i].bDescrType, 0x80);

                Notify(PSTR("\r\nwDescriptorLength:\t"), 0x80);
                PrintHex<uint16_t > (pLT[i].wDescriptorLength, 0x80);
        }
        Notify(PSTR("\r\n"), 0x80);
}


#endif // __CONFDESCPARSER_H__