USB_Host_Shield_2.0/address.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(__ADDRESS_H__)
#define __ADDRESS_H__

#include <inttypes.h>
#include <stddef.h>
#include "max3421e.h"


/* NAK powers. To save space in endpoint data structure, amount of retries before giving up and returning 0x4 is stored in */
/* bmNakPower as a power of 2. The actual nak_limit is then calculated as nak_limit = ( 2^bmNakPower - 1) */
#define USB_NAK_MAX_POWER		15		//NAK binary order maximum value
#define USB_NAK_DEFAULT			14		//default 32K-1 NAKs before giving up
#define USB_NAK_NOWAIT			1		//Single NAK stops transfer
#define USB_NAK_NONAK			0		//Do not count NAKs, stop retrying after USB Timeout

struct EpInfo {
        uint8_t epAddr; // Endpoint address
        uint8_t maxPktSize; // Maximum packet size

        union {
                uint8_t epAttribs;

                struct {
                        uint8_t bmSndToggle : 1; // Send toggle, when zero bmSNDTOG0, bmSNDTOG1 otherwise
                        uint8_t bmRcvToggle : 1; // Send toggle, when zero bmRCVTOG0, bmRCVTOG1 otherwise
                        uint8_t bmNakPower : 6; // Binary order for NAK_LIMIT value
                } __attribute__((packed));
        };
} __attribute__((packed));

//	  7   6   5   4   3   2   1   0
//  ---------------------------------
//  |   | H | P | P | P | A | A | A |
//  ---------------------------------
//
// H - if 1 the address is a hub address
// P - parent hub address
// A - device address / port number in case of hub
//

struct UsbDeviceAddress {

        union {

                struct {
                        uint8_t bmAddress : 3; // device address/port number
                        uint8_t bmParent : 3; // parent hub address
                        uint8_t bmHub : 1; // hub flag
                        uint8_t bmReserved : 1; // reserved, must be zerro
                } __attribute__((packed));
                uint8_t devAddress;
        };
} __attribute__((packed));

#define bmUSB_DEV_ADDR_ADDRESS		0x07
#define bmUSB_DEV_ADDR_PARENT		0x38
#define bmUSB_DEV_ADDR_HUB		0x40

struct UsbDevice {
        EpInfo *epinfo; // endpoint info pointer
        uint8_t address; // address
        uint8_t epcount; // number of endpoints
        bool lowspeed; // indicates if a device is the low speed one
        //	uint8_t			devclass;		// device class
} __attribute__((packed));

class AddressPool {
public:
        virtual UsbDevice* GetUsbDevicePtr(uint8_t addr) = 0;
        virtual uint8_t AllocAddress(uint8_t parent, bool is_hub = false, uint8_t port = 0) = 0;
        virtual void FreeAddress(uint8_t addr) = 0;
};

typedef void (*UsbDeviceHandleFunc)(UsbDevice *pdev);

#define ADDR_ERROR_INVALID_INDEX		0xFF
#define ADDR_ERROR_INVALID_ADDRESS		0xFF

template <const uint8_t MAX_DEVICES_ALLOWED>
class AddressPoolImpl : public AddressPool {
        EpInfo dev0ep; //Endpoint data structure used during enumeration for uninitialized device

        uint8_t hubCounter; // hub counter is kept
        // in order to avoid hub address duplication

        UsbDevice thePool[MAX_DEVICES_ALLOWED];

        // Initializes address pool entry

        void InitEntry(uint8_t index) {
                thePool[index].address = 0;
                thePool[index].epcount = 1;
                thePool[index].lowspeed = 0;
                thePool[index].epinfo = &dev0ep;
        };
        // Returns thePool index for a given address

        uint8_t FindAddressIndex(uint8_t address = 0) {
                for(uint8_t i = 1; i < MAX_DEVICES_ALLOWED; i++) {
                        if(thePool[i].address == address)
                                return i;
                }
                return 0;
        };
        // Returns thePool child index for a given parent

        uint8_t FindChildIndex(UsbDeviceAddress addr, uint8_t start = 1) {
                for(uint8_t i = (start < 1 || start >= MAX_DEVICES_ALLOWED) ? 1 : start; i < MAX_DEVICES_ALLOWED; i++) {
                        if(((UsbDeviceAddress*) & thePool[i].address)->bmParent == addr.bmAddress)
                                return i;
                }
                return 0;
        };
        // Frees address entry specified by index parameter

        void FreeAddressByIndex(uint8_t index) {
                // Zerro field is reserved and should not be affected
                if(index == 0)
                        return;

                // If a hub was switched off all port addresses should be freed
                if(((UsbDeviceAddress*) & thePool[index].address)->bmHub == 1) {
                        for(uint8_t i = 1; (i = FindChildIndex(*((UsbDeviceAddress*) & thePool[index].address), i));)
                                FreeAddressByIndex(i);

                        // If the hub had the last allocated address, hubCounter should be decremented
                        if(hubCounter == ((UsbDeviceAddress*) & thePool[index].address)->bmAddress)
                                hubCounter--;
                }
                InitEntry(index);
        }
        // Initializes the whole address pool at once

        void InitAllAddresses() {
                for(uint8_t i = 1; i < MAX_DEVICES_ALLOWED; i++)
                        InitEntry(i);

                hubCounter = 0;
        };

public:

        AddressPoolImpl() : hubCounter(0) {
                // Zero address is reserved
                InitEntry(0);

                thePool[0].address = 0;
                thePool[0].epinfo = &dev0ep;
                dev0ep.epAddr = 0;
                dev0ep.maxPktSize = 8;
                dev0ep.epAttribs = 0; //set DATA0/1 toggles to 0
                dev0ep.bmNakPower = USB_NAK_MAX_POWER;

                InitAllAddresses();
        };
        // Returns a pointer to a specified address entry

        virtual UsbDevice* GetUsbDevicePtr(uint8_t addr) {
                if(!addr)
                        return thePool;

                uint8_t index = FindAddressIndex(addr);

                return(!index) ? NULL : thePool + index;
        };

        // Performs an operation specified by pfunc for each addressed device

        void ForEachUsbDevice(UsbDeviceHandleFunc pfunc) {
                if(!pfunc)
                        return;

                for(uint8_t i = 1; i < MAX_DEVICES_ALLOWED; i++)
                        if(thePool[i].address)
                                pfunc(thePool + i);
        };
        // Allocates new address

        virtual uint8_t AllocAddress(uint8_t parent, bool is_hub = false, uint8_t port = 0) {
                /* if (parent != 0 && port == 0)
                        Serial.println("PRT:0"); */

                if(parent > 127 || port > 7)
                        return 0;

                if(is_hub && hubCounter == 7)
                        return 0;

                // finds first empty address entry starting from one
                uint8_t index = FindAddressIndex(0);

                if(!index) // if empty entry is not found
                        return 0;

                if(parent == 0) {
                        if(is_hub) {
                                thePool[index].address = 0x41;
                                hubCounter++;
                        } else
                                thePool[index].address = 1;

                        return thePool[index].address;
                }

                UsbDeviceAddress addr;

                addr.bmParent = ((UsbDeviceAddress*) & parent)->bmAddress;

                if(is_hub) {
                        addr.bmHub = 1;
                        addr.bmAddress = ++hubCounter;
                } else {
                        addr.bmHub = 0;
                        addr.bmAddress = port;
                }
                thePool[index].address = *((uint8_t*) & addr);
                /*
                                Serial.print("Addr:");
                                Serial.print(addr.bmHub, HEX);
                                Serial.print(".");
                                Serial.print(addr.bmParent, HEX);
                                Serial.print(".");
                                Serial.println(addr.bmAddress, HEX);
                 */
                return thePool[index].address;
        };
        // Empties pool entry

        virtual void FreeAddress(uint8_t addr) {
                // if the root hub is disconnected all the addresses should be initialized
                if(addr == 0x41) {
                        InitAllAddresses();
                        return;
                }
                uint8_t index = FindAddressIndex(addr);
                FreeAddressByIndex(index);
        };
        // Returns number of hubs attached
        // It can be rather helpfull to find out if there are hubs attached than getting the exact number of hubs.
        //uint8_t GetNumHubs()
        //{
        //	return hubCounter;
        //};
        //uint8_t GetNumDevices()
        //{
        //	uint8_t counter = 0;

        //	for (uint8_t i=1; i<MAX_DEVICES_ALLOWED; i++)
        //		if (thePool[i].address != 0);
        //			counter ++;

        //	return counter;
        //};
};

#endif // __ADDRESS_H__