Dependencies:   mbed

Revision:
0:76427232f435
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/USB_HOST/USBHost.cpp	Thu Feb 16 00:41:26 2012 +0000
@@ -0,0 +1,1100 @@
+
+/*
+Copyright (c) 2010 Peter Barrett
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "mbed.h"
+#include "USBHost.h"
+#include "Utils.h"
+
+//    Config (default uses x bytes)
+#define MAX_DEVICES 8                // Max number of devices
+#define MAX_ENDPOINTS_TOTAL 16        // Max number of endpoints total
+#define MAX_ENDPOINTS_PER_DEVICE 8    // Max number of endpoints for any one device
+
+#define  USBLOG 1
+#if USBLOG
+#define  LOG(...)       printf(__VA_ARGS__)
+#else 
+#define  LOG(...)       do {} while(0)
+#endif
+
+//Eli Adds
+unsigned char USB_Disk_Detected = 0;
+unsigned char USB_Disk_Device = 0;
+
+// USB host structures
+
+#define USB_RAM_SIZE 16*1024    // AHB SRAM block 1 TODO MACHINE DEPENDENT
+#define USB_RAM_BASE 0x2007C000
+
+#define TOKEN_SETUP 0
+#define TOKEN_IN  1
+#define TOKEN_OUT 2
+
+//    Status flags from hub
+#define PORT_CONNECTION 0
+#define PORT_ENABLE  1
+#define PORT_SUSPEND  2
+#define PORT_OVER_CURRENT 3
+#define PORT_RESET 4
+#define PORT_POWER 8
+#define PORT_LOW_SPEED 9
+
+#define C_PORT_CONNECTION 16
+#define C_PORT_ENABLE 17
+#define C_PORT_SUSPEND 18
+#define C_PORT_OVER_CURRENT 19
+#define C_PORT_RESET 20
+
+typedef struct {
+    u8 bm_request_type;
+    u8 b_request;
+    u16 w_value;
+    u16 w_index;
+    u16 w_length;
+} Setup;
+
+
+//    Hub stuff is kept private just to keep api simple
+int SetPortFeature(int device, int feature, int index);
+int ClearPortFeature(int device, int feature, int index);
+int SetPortPower(int device, int port);
+int SetPortReset(int device, int port);
+int GetPortStatus(int device, int port, u32* status);
+
+//===================================================================
+//===================================================================
+//    Hardware defines
+
+//    HcControl
+#define PeriodicListEnable    0x00000004
+#define    IsochronousEnable    0x00000008
+#define    ControlListEnable    0x00000010
+#define    BulkListEnable        0x00000020
+#define    OperationalMask        0x00000080
+#define    HostControllerFunctionalState    0x000000C0
+
+//    HcCommandStatus
+#define HostControllerReset    0x00000001
+#define ControlListFilled    0x00000002
+#define BulkListFilled        0x00000004
+
+//    HcInterruptStatus Register
+#define    WritebackDoneHead        0x00000002
+#define    StartofFrame            0x00000004
+#define ResumeDetected            0x00000008
+#define UnrecoverableError        0x00000010
+#define FrameNumberOverflow        0x00000020
+#define RootHubStatusChange        0x00000040
+#define OwnershipChange            0x00000080
+#define MasterInterruptEnable    0x80000000
+
+//    HcRhStatus
+#define SetGlobalPower            0x00010000
+#define DeviceRemoteWakeupEnable    0x00008000
+
+//    HcRhPortStatus (hub 0, port 1)
+#define CurrentConnectStatus    0x00000001
+#define    PortEnableStatus        0x00000002
+#define PortSuspendStatus        0x00000004
+#define PortOverCurrentIndicator    0x00000008
+#define PortResetStatus            0x00000010
+
+#define PortPowerStatus            0x00000100
+#define LowspeedDevice            0x00000200
+#define HighspeedDevice            0x00000400
+
+#define ConnectStatusChange    (CurrentConnectStatus << 16)
+#define PortResetStatusChange    (PortResetStatus << 16)
+
+
+#define  TD_ROUNDING        (u32)0x00040000
+#define  TD_SETUP            (u32)0x00000000
+#define  TD_IN                (u32)0x00100000
+#define  TD_OUT                (u32)0x00080000
+#define  TD_DELAY_INT(x)    (u32)((x) << 21)
+#define  TD_TOGGLE_0        (u32)0x02000000
+#define  TD_TOGGLE_1        (u32)0x03000000
+#define  TD_CC                (u32)0xF0000000
+
+//    HostController EndPoint Descriptor
+typedef struct {
+    volatile u32    Control;
+    volatile u32    TailTd;
+    volatile u32    HeadTd;
+    volatile u32    Next;
+} HCED;
+
+// HostController Transfer Descriptor
+typedef struct {
+    volatile u32    Control;
+    volatile u32    CurrBufPtr;
+    volatile u32    Next;
+    volatile u32    BufEnd;
+} HCTD;
+
+// Host Controller Communication Area
+typedef struct {
+    volatile u32    InterruptTable[32];
+    volatile u16    FrameNumber;
+    volatile u16    FrameNumberPad;
+    volatile u32    DoneHead;
+    volatile u8        Reserved[120];
+} HCCA;
+
+//====================================================================================
+//====================================================================================
+
+class HostController;
+class Endpoint;
+class Device;
+
+//      must be 3*16 bytes long
+class Endpoint
+{
+public:
+    HCED    EndpointDescriptor;    // Pointer to EndpointDescriptor == Pointer to Endpoint
+    HCTD    TDHead;
+
+    enum State
+    {
+        Free,
+        NotQueued,
+        Idle,
+        SetupQueued,
+        DataQueued,
+        StatusQueued,
+        CallbackPending
+    };
+    
+    volatile u8 CurrentState;
+    u8        Flags;            // 0x80 In, 0x03 mask endpoint type
+
+    u16        Length;
+    u8*        Data;
+    USBCallback Callback;     // Must be a multiple of 16 bytes long
+    void*  UserData;
+  
+    int Address()
+    {
+        int ep = (EndpointDescriptor.Control >> 7) & 0xF;
+        if (ep)
+            ep |= Flags & 0x80;
+        return ep;
+    }
+    
+    int Device()
+    {
+        return EndpointDescriptor.Control & 0x7F;
+    }
+
+    int Status()
+    {
+        return (TDHead.Control >> 28) & 0xF;
+    }
+
+    u32 Enqueue(u32 head)
+    {
+        if (CurrentState == NotQueued)
+        {
+            EndpointDescriptor.Next = head;
+            head = (u32)&EndpointDescriptor;
+            CurrentState = Idle;
+        }
+        return head;
+    }
+};
+
+class Device
+{
+public:
+    u8    _endpointMap[MAX_ENDPOINTS_PER_DEVICE*2];
+    u8    Hub;
+    u8    Port;
+    u8    Addr;
+    u8    Pad;
+
+    //    Only if this device is a hub
+    u8    HubPortCount;    // nonzero if this is a hub
+    u8    HubInterruptData;
+    u8    HubMap;
+    u8    HubMask;
+
+    int Flags;        // 1 = Disconnected
+
+    Setup    SetupBuffer;
+
+    // Allocate endpoint zero
+    int Init(DeviceDescriptor* d, int hub, int port, int addr, int lowSpeed)
+    {
+        Hub = hub;
+        Port = port;
+        Addr = addr;
+        Flags = lowSpeed;
+        memset(_endpointMap,0xFF,sizeof(_endpointMap));
+        return 0;
+    }
+
+    int SetEndpointIndex(int ep, int endpointIndex)
+    {
+        for (int i = 0; i < MAX_ENDPOINTS_PER_DEVICE*2; i += 2)
+        {
+            if (_endpointMap[i] == 0xFF)    // Add endpoint to map
+            {
+                _endpointMap[i] = ep;
+                _endpointMap[i+1] = endpointIndex;
+                return 0;
+            }
+        }
+        return ERR_ENDPOINT_NONE_LEFT;
+    }
+
+    int GetEndpointIndex(int ep)
+    {
+        for (int i = 0; i < MAX_ENDPOINTS_PER_DEVICE*2; i += 2)
+        {
+            if (_endpointMap[i] == ep)
+                return _endpointMap[i+1];
+            if (_endpointMap[i] == 0xFF)
+                break;
+        }
+        return -1;
+    }
+};
+
+class HostController
+{
+public:
+    HCCA        CommunicationArea;
+    Endpoint    Endpoints[MAX_ENDPOINTS_TOTAL];    // Multiple of 16
+    
+    Endpoint    EndpointZero;                        // For device enumeration
+    HCTD        _commonTail;
+    Setup        _setupZero;
+    
+    Device    Devices[MAX_DEVICES];
+    u32    _frameNumber;            // 32 bit ms counter
+
+    u8    _callbacksPending;        //    Endpoints with callbacks are pending, set from ISR via ProcessDoneQueue
+    u8    _rootHubStatusChange;    //    Root hub status has changed, set from ISR
+    u8    _unused0;
+    u8    _unused1;
+
+    u8    _connectPending;    //    Reset has initiated a connect
+    u8    _connectCountdown;    //    Number of ms left after reset before we can connect
+    u8    _connectHub;        //    Will connect on this hub
+    u8    _connectPort;        //    ... and this port
+
+    u8    SRAM[0];            // Start of free SRAM
+
+    void Loop()
+    {
+        u16 elapsed = CommunicationArea.FrameNumber - (u16)_frameNumber;    // extend to 32 bits
+        _frameNumber += elapsed;
+
+        // Do callbacks, if any
+        while (_callbacksPending)
+        {
+            for (int i = 0; i < MAX_ENDPOINTS_TOTAL; i++)
+            {
+                Endpoint* endpoint = Endpoints + i;
+                if (endpoint->CurrentState == Endpoint::CallbackPending)
+                {
+                    _callbacksPending--;
+                    endpoint->CurrentState = Endpoint::Idle;
+                    endpoint->Callback(endpoint->Device(),endpoint->Address(),endpoint->Status(),endpoint->Data,endpoint->Length,endpoint->UserData);
+                }
+            }
+        }
+
+        //    Deal with changes on the root hub
+        if (_rootHubStatusChange)
+        {
+            u32 status = LPC_USB->HcRhPortStatus1;
+            _rootHubStatusChange = 0;
+            if (status >> 16)
+            {
+                HubStatusChange(0,1,status);
+                LPC_USB->HcRhPortStatus1 = status & 0xFFFF0000;    // clear status changes
+            }
+        }
+
+        //    Connect after reset timeout
+        if (_connectCountdown)
+        {
+            if (elapsed >= _connectCountdown)
+            {
+                _connectCountdown = 0;
+                Connect(_connectHub,_connectPort & 0x7F,_connectPort & 0x80);
+            } else
+                _connectCountdown -= elapsed;
+        }
+    }
+
+    //    HubInterrupt - bitmap in dev->HubInterruptData
+    void HubInterrupt(int device)
+    {
+        Device* dev = &Devices[device-1];
+        for (int i = 0; i < dev->HubPortCount; i++)
+        {
+            int port = i+1;
+            if (dev->HubInterruptData & (1 << port))
+            {
+                u32 status = 0;
+                GetPortStatus(device,port,&status);
+                if (status >> 16)
+                {
+                    if (_connectPending && (status & ConnectStatusChange))
+                        continue;    // Don't connect again until previous device has been added and addressed
+
+                    HubStatusChange(device,port,status);
+                    if (status & ConnectStatusChange)
+                        ClearPortFeature(device,C_PORT_CONNECTION,port);
+                    if (status & PortResetStatusChange)
+                        ClearPortFeature(device,C_PORT_RESET,port);
+                }
+            }
+        }
+    }
+
+    static void HubInterruptCallback(int device, int endpoint, int status, u8* data, int len, void* userData)
+    {
+        HostController* controller = (HostController*)userData;
+        if (status == 0)
+            controller->HubInterrupt(device);
+        USBInterruptTransfer(device,endpoint,data,1,HubInterruptCallback,userData);
+    }
+
+    int InitHub(int device)
+    {
+        u8 buf[16];
+        int r= USBControlTransfer(device,DEVICE_TO_HOST | REQUEST_TYPE_CLASS | RECIPIENT_DEVICE,GET_DESCRIPTOR,(DESCRIPTOR_TYPE_HUB << 8),0,buf,sizeof(buf));
+        if (r < 0)
+            return ERR_HUB_INIT_FAILED;
+        
+        //    turn on power on the hubs ports
+        Device* dev = &Devices[device-1];
+        int ports = buf[2];
+        dev->HubPortCount = ports;
+        for (int i = 0; i < ports; i++)
+            SetPortPower(device,i+1);
+        
+        // Enable hub change interrupts
+        return USBInterruptTransfer(device,0x81,&dev->HubInterruptData,1,HubInterruptCallback,this);
+    }
+    
+    int AddEndpoint(int device, int ep, int attributes, int maxPacketSize, int interval)
+    {
+        LOG("AddEndpoint D:%02X A:%02X T:%02X P:%04X I:%02X\n",device,ep,attributes,maxPacketSize,interval);
+        Device* dev = &Devices[device-1];
+        Endpoint* endpoint = AllocateEndpoint(device,ep,attributes,maxPacketSize);
+        if (!endpoint)
+            return ERR_ENDPOINT_NONE_LEFT;
+        dev->SetEndpointIndex(ep,endpoint - Endpoints);
+        endpoint->EndpointDescriptor.Control |= dev->Flags; // Map in slow speed
+        return 0;  // TODO ed->bInterval
+    }
+    
+    int AddEndpoint(int device, EndpointDescriptor* ed)
+    {
+        return AddEndpoint(device,ed->bEndpointAddress,ed->bmAttributes,ed->wMaxPacketSize,ed->bInterval);
+    }
+
+    //      allocate a endpoint
+    Endpoint* AllocateEndpoint(int device, int endpointAddress, int type, int maxPacketSize)
+    {
+        for (int i = 0; i < MAX_ENDPOINTS_TOTAL; i++)
+        {
+            Endpoint* ep = &Endpoints[i];
+            if (ep->CurrentState == 0)
+            {
+                //LOG("Allocated endpoint %d to %02X:%02X\n",i,device,endpointAddress);
+                ep->Flags = (endpointAddress & 0x80) | (type & 3);
+                ep->CurrentState = Endpoint::NotQueued;
+                ep->EndpointDescriptor.Control = (maxPacketSize << 16) | ((endpointAddress & 0x7F) << 7) | device;
+                return ep;
+            }
+        }
+        return 0;
+    }
+
+    Endpoint* GetEndpoint(int device, int ep)
+    {
+        if (device == 0)
+        {
+            //printf("WARNING: USING DEVICE 0\n");
+            return &EndpointZero;
+        }
+        if (device > MAX_DEVICES)
+            return 0;
+        int i = Devices[device-1].GetEndpointIndex(ep);
+        if (i == -1)
+            return 0;
+        return Endpoints + i;
+    }
+
+    int Transfer(Endpoint* endpoint, int token, u8* data, int len, int state)
+    {
+        //LOG("Transfer %02X T:%d Len:%d S:%d\n",endpoint->Address(),token,len,state);
+    
+        int toggle = 0;
+        if (endpoint->Address() == 0)
+            toggle = (token == TOKEN_SETUP) ? TD_TOGGLE_0 : TD_TOGGLE_1;
+
+        if (token != TOKEN_SETUP)
+            token = (token == TOKEN_IN ? TD_IN : TD_OUT);
+
+        HCTD* head = &endpoint->TDHead;
+        HCTD* tail = &_commonTail;
+
+        head->Control = TD_ROUNDING | token | TD_DELAY_INT(0) | toggle | TD_CC; 
+        head->CurrBufPtr = (u32)data;
+        head->BufEnd = (u32)(data + len - 1);
+        head->Next = (u32)tail;
+
+        HCED* ed = &endpoint->EndpointDescriptor;
+        ed->HeadTd = (u32)head | (ed->HeadTd & 0x00000002);    // carry toggle
+        ed->TailTd = (u32)tail;
+        
+        //HCTD* td = head;
+        //LOG("%04X TD %08X %08X %08X Next:%08X\n",CommunicationArea.FrameNumber,td->Control,td->CurrBufPtr,td->BufEnd,td->Next);
+        //LOG("%04X ED %08X %08X %08X\n",CommunicationArea.FrameNumber,ed->Control,ed->HeadTd,ed->TailTd);
+        
+        switch (endpoint->Flags & 3)
+        {
+            case ENDPOINT_CONTROL:
+                LPC_USB->HcControlHeadED = endpoint->Enqueue(LPC_USB->HcControlHeadED);    // May change state NotQueued->Idle
+                endpoint->CurrentState = state;                                               // Get in before an int
+                LPC_USB->HcCommandStatus = LPC_USB->HcCommandStatus | ControlListFilled;
+                LPC_USB->HcControl = LPC_USB->HcControl | ControlListEnable;
+                break;
+
+            case ENDPOINT_BULK:
+                LPC_USB->HcBulkHeadED = endpoint->Enqueue(LPC_USB->HcBulkHeadED);
+                endpoint->CurrentState = state;
+                LPC_USB->HcCommandStatus = LPC_USB->HcCommandStatus | BulkListFilled;
+                LPC_USB->HcControl = LPC_USB->HcControl | BulkListEnable;
+                break;
+
+            case ENDPOINT_INTERRUPT:
+                CommunicationArea.InterruptTable[0] = endpoint->Enqueue(CommunicationArea.InterruptTable[0]);
+                endpoint->CurrentState = state;
+                LPC_USB->HcControl |= PeriodicListEnable;
+                break;
+        }
+        return 0;
+    }
+    
+    //    Remove an endpoint from an active queue
+    bool Remove(HCED* ed, volatile HCED** queue)
+    {
+        if (*queue == 0)
+            return false;
+        if (*queue == (volatile HCED*)ed)
+        {
+            *queue = (volatile HCED*)ed->Next;    // At head of queue
+            return true;
+        }
+
+        volatile HCED* head = *queue;
+        while (head)
+        {
+            if (head->Next == (u32)ed)
+            {
+                head->Next = ed->Next;
+                return true;
+            }
+            head = (volatile HCED*)head->Next;
+        }
+        return false;
+    }
+
+    void Release(Endpoint* endpoint)
+    {
+        if (endpoint->CurrentState == Endpoint::NotQueued)
+        {
+            // Never event used it, nothing to do
+        }
+        else
+        {
+            HCED* ed = (HCED*)endpoint;
+            ed->Control |= 0x4000;    // SKIP
+            switch (endpoint->Flags & 0x03)
+            {
+                case ENDPOINT_CONTROL:
+                    Remove(ed,(volatile HCED**)&LPC_USB->HcControlHeadED);
+                    break;
+                case ENDPOINT_BULK:
+                    Remove(ed,(volatile HCED**)&LPC_USB->HcBulkHeadED);
+                    break;
+                case ENDPOINT_INTERRUPT:
+                    for (int i = 0; i < 32; i++)
+                        Remove(ed,(volatile HCED**)&CommunicationArea.InterruptTable[i]);
+                    break;
+            }
+
+            u16 fn = CommunicationArea.FrameNumber;
+            while (fn == CommunicationArea.FrameNumber)
+                ;    // Wait for next frame
+
+        }
+
+        //    In theory, the endpoint is now dead.
+        //    TODO: Will Callbacks ever be pending? BUGBUG
+        memset(endpoint,0,sizeof(Endpoint));
+    }
+
+    //      Pop the last TD from the list
+    HCTD* Reverse(HCTD* current) 
+    { //int n = 0;
+        HCTD *result = NULL,*temp; 
+        while (current) 
+        { //n++;
+            temp = (HCTD*)current->Next; 
+            current->Next = (u32)result;
+            result = current;
+            current = temp;
+        }
+        //if (n>1) printf("%d TD's on Done Queue\n", n);
+        return result;
+    }
+
+    //      Called from interrupt...
+    //      Control endpoints use a state machine to progress through the transfers
+    void ProcessDoneQueue(u32 tdList)
+    {
+        HCTD* list = Reverse((HCTD*)tdList);//because completed transfers were added to the head of the list
+        while (list)
+        {//horrible hack: an Endpoint starts with an HCED and an HCTD and apparently all HCTDs are contained in Endpoints this way
+         //furthermore the sizeof an HCTD equeals the size of an HCED, hence the next expression gives indeed the Endpoint* for the HCTD
+            Endpoint* endpoint = (Endpoint*)(list-1);
+            list = (HCTD*)list->Next;
+            int ep = endpoint->Address();
+            bool in = endpoint->Flags & 0x80;
+            int status = (endpoint->TDHead.Control >> 28) & 0xF;
+//the printf below is essential for correct working !?!? remove it and some messages will be missed
+            //LOG("ProcessDoneQueue %02X %08X\n",ep,endpoint->TDHead.Control);
+wait_us(0);//200, 100, 50, 20, 10, 5, 2, 1,0 works, deleting the statement does not work
+//I suspect it has to do with interrupt priorities rather than with delays
+            if (status != 0)
+            {
+                LOG("ProcessDoneQueue status %02X %d\n",ep,status);
+                endpoint->CurrentState = Endpoint::Idle;
+            } else {
+                switch (endpoint->CurrentState)
+                {
+                    case Endpoint::SetupQueued:
+                        if (endpoint->Length == 0){
+                            Transfer(endpoint,in ? TOKEN_OUT : TOKEN_IN,0,0,Endpoint::StatusQueued);    // Skip Data Phase
+                        } else {//here is a potential deadlock
+                    //printf("Deadlock Avoidance, ep=%02x, in=%d\n", ep, in);//with printf before transfer -> no deadlock
+                            Transfer(endpoint,in ? TOKEN_IN : TOKEN_OUT,endpoint->Data,endpoint->Length, Endpoint::DataQueued);    // Setup is done, now Data
+                    //printf("SetupQueued->DataQueued\n");//with printf after Transfer ->deadlock
+                        }
+                        break;
+
+                    case Endpoint::DataQueued:
+                        if (endpoint->TDHead.CurrBufPtr)
+                            endpoint->Length = endpoint->TDHead.CurrBufPtr - (u32)endpoint->Data;
+
+                        if (ep == 0){
+                            Transfer(endpoint,in ? TOKEN_OUT : TOKEN_IN,0,0,Endpoint::StatusQueued);    // Data is done, now Status, Control only
+                        } else
+                            endpoint->CurrentState = Endpoint::Idle;
+                        break;
+
+                    case Endpoint::StatusQueued:    // Transaction is done
+                        endpoint->CurrentState = Endpoint::Idle;
+                        break;
+                }
+            }
+
+            //      Complete, flag if we need a callback
+            if (endpoint->Callback && endpoint->CurrentState == Endpoint::Idle)
+            {
+                endpoint->CurrentState = Endpoint::CallbackPending;
+                _callbacksPending++;
+            }
+        }
+    }
+
+    //    Hack to reset devices that don't want to connect
+    int AddDevice(int hub, int port, bool isLowSpeed)
+    {
+        int device = AddDeviceCore(hub,port,isLowSpeed);
+        if (device < 0)
+        {
+            LOG("========RETRY ADD DEVICE========\n");    // This will go for ever.. TODO power cycle root?
+            Disconnect(hub,port);    // Could not read descriptor at assigned address, reset this port and try again
+            ResetPort(hub,port);    // Cheap bluetooth dongles often need this on a hotplug
+            return -1;
+        }
+        return device;
+    }
+
+    int AddDeviceCore(int hub, int port, bool isLowSpeed)
+    {
+        int lowSpeed = isLowSpeed ? 0x2000 : 0;
+        DeviceDescriptor desc;
+        EndpointZero.EndpointDescriptor.Control = (8 << 16) | lowSpeed;               // MaxPacketSize == 8
+        int r = GetDescriptor(0,DESCRIPTOR_TYPE_DEVICE,0,(u8*)&desc,8);
+        if (r < 0)
+        {
+            LOG("FAILED TO LOAD DESCRIPTOR FOR DEVICE 0\n");
+            return r;
+        }
+
+        EndpointZero.EndpointDescriptor.Control = (desc.bMaxPacketSize << 16) | lowSpeed;     // Actual MaxPacketSize
+        r = GetDescriptor(0,DESCRIPTOR_TYPE_DEVICE,0,(u8*)&desc,sizeof(desc));
+        if (r < 0)
+            return r;
+
+        LOG("\nClass %02X found %04X:%04X\n\n",desc.bDeviceClass,desc.idVendor,desc.idProduct);
+
+        //      Now assign the device an address, move off EndpointZero
+        int device = 0;
+        for (int i = 0; i < MAX_DEVICES; i++)
+        {
+            if (Devices[i].Port == 0)
+            {
+                device = i+1;
+                break;
+            }
+        }
+        if (!device)
+            return ERR_DEVICE_NONE_LEFT;
+
+        r = SetAddress(0,device);
+        if (r)
+            return r;
+        DelayMS(2);
+        
+        // Now at a nonzero address, create control endpoint
+        Device* dev = &Devices[device-1];
+        dev->Init(&desc,hub,port,device,lowSpeed);
+        AddEndpoint(device,0,ENDPOINT_CONTROL,desc.bMaxPacketSize,0);
+        _connectPending = 0;
+
+        //    Verify this all works
+        r = GetDescriptor(device,DESCRIPTOR_TYPE_DEVICE,0,(u8*)&desc,sizeof(desc));
+        if (r < 0)
+            return r;
+
+        //    Set to interface 0 by default
+        //    Calls LoadDevice if interface is found
+        r = SetConfigurationAndInterface(device,1,0,&desc);
+
+        if (desc.bDeviceClass == CLASS_HUB)
+            InitHub(device);            // Handle hubs in this code
+
+        return device;
+    }
+
+    // Walk descriptors and create endpoints for a given device
+    // TODO configuration !=1, alternate settings etc.
+    int SetConfigurationAndInterface(int device, int configuration, int interfaceNumber, DeviceDescriptor* desc)
+    {
+        u8 buffer[255];
+        int err = GetDescriptor(device,DESCRIPTOR_TYPE_CONFIGURATION,0,buffer,sizeof(buffer));
+        if (err < 0)
+            return err;
+
+        err = SetConfiguration(device,configuration);
+        if (err < 0)
+            return err;
+
+        //    Add the endpoints for this interface
+        int len = buffer[2] | (buffer[3] << 8);
+        u8* d = buffer;
+        u8* end = d + len;
+        InterfaceDescriptor* found = 0;
+        while (d < end)
+        {
+            if (d[1] == DESCRIPTOR_TYPE_INTERFACE)
+            {
+                InterfaceDescriptor* id = (InterfaceDescriptor*)d;
+                if (id->bInterfaceNumber == interfaceNumber)
+                {
+                    found = id;
+                    d += d[0];
+                    while (d < end && d[1] != DESCRIPTOR_TYPE_INTERFACE)
+                    {
+                        switch (d[1])
+                        {
+                            case DESCRIPTOR_TYPE_ENDPOINT:
+                                AddEndpoint(device,(EndpointDescriptor*)d);
+                                break;
+                            default:
+                                LOG("Skipping descriptor %02X (%d bytes)\n",d[1],d[0]);
+                        }
+                        d += d[0];
+                    }
+                }
+            }
+            d += d[0];
+        }
+
+        if (!found)
+            return ERR_INTERFACE_NOT_FOUND;
+        OnLoadDevice(device,desc,found);
+        return 0;
+    }
+
+    void Init()
+    {
+        LOG("USB INIT (Controller is %d bytes)\n",sizeof(*this));
+        memset(this,0,sizeof(HostController));
+        EndpointZero.CurrentState = Endpoint::NotQueued;
+        HWInit(&CommunicationArea);
+        DelayMS(10);
+    }
+
+    void ResetPort(int hub, int port)
+    {
+        LOG("ResetPort Hub:%d Port:%d\n",hub,port);
+        _connectPending++;            // Only reset/add 1 device at a time
+        if (hub == 0)
+            LPC_USB->HcRhPortStatus1 = PortResetStatus;    // Reset Root Hub, port 1
+        else
+            SetPortReset(hub,port);    // or reset other hub
+    }
+
+    void Disconnect(int hub, int port)
+    {
+        LOG("Disconnect Hub:%d Port:%d\n",hub,port);    // Mark a device for destruction
+      
+      if(port ==USB_Disk_Device)
+      {
+        USB_Disk_Detected = 0;
+      }
+      
+        for (int i = 0; i < MAX_DEVICES; i++)
+        {
+            Device* dev = Devices + i;
+            if (dev->Port == port && dev->Hub == hub)
+            {
+                //    Disconnect everything that is attached to this device if it is a hub
+                for (int p = 0; p < dev->HubPortCount; p++)
+                    Disconnect(i+1,p+1);
+
+                //    Now release endpoints
+                for (int j = 1; j < MAX_ENDPOINTS_PER_DEVICE*2; j += 2)
+                {
+                    u8 endpointIndex = dev->_endpointMap[j];
+                    if (endpointIndex != 0xFF)
+                        Release(Endpoints + endpointIndex);
+                }
+                dev->Port = 0;    // Device is now free
+                dev->Flags = 0;
+                return;
+            }
+          }
+    }
+
+    // called after reset
+    void Connect(int hub, int port, bool lowspeed)
+    {
+        LOG("Connect Hub:%d Port:%d %s\n",hub,port,lowspeed ? "slow" : "full");
+        AddDevice(hub,port,lowspeed);
+    }
+
+    // Called from interrupt
+    void HubStatusChange(int hub, int port, u32 status)
+    {
+        LOG("HubStatusChange Hub:%d Port:%d %08X\n",hub,port,status);
+        if (status & ConnectStatusChange)
+        {
+            if (status & CurrentConnectStatus)    // Connecting
+                ResetPort(hub,port);            // Reset to initiate connect (state machine?)
+            else
+                Disconnect(hub,port);
+        }
+
+        if (status & PortResetStatusChange)
+        {
+            if (!(status & PortResetStatus))
+            {
+                _connectCountdown = 200;        // Schedule a connection in 200ms
+                if (status & LowspeedDevice)
+                    port |= 0x80;
+                _connectHub = hub;
+                _connectPort = port;
+            }
+        }
+    }
+
+    #define HOST_CLK_EN        (1<<0)
+    #define PORTSEL_CLK_EN    (1<<3)
+    #define AHB_CLK_EN        (1<<4)
+    #define CLOCK_MASK        (HOST_CLK_EN | PORTSEL_CLK_EN | AHB_CLK_EN)
+
+    #define  FRAMEINTERVAL        (12000-1)    // 1ms
+    #define  DEFAULT_FMINTERVAL    ((((6 * (FRAMEINTERVAL - 210)) / 7) << 16) | FRAMEINTERVAL)
+
+    void DelayMS(int ms)
+    {
+        u16 f = ms + CommunicationArea.FrameNumber;
+        while (f != CommunicationArea.FrameNumber)
+            ;
+    }
+
+    static void HWInit(HCCA* cca)
+    {
+        NVIC_DisableIRQ(USB_IRQn);
+        
+        // turn on power for USB
+        LPC_SC->PCONP        |= (1UL<<31);
+        // Enable USB host clock, port selection and AHB clock
+        LPC_USB->USBClkCtrl |= CLOCK_MASK;
+        // Wait for clocks to become available
+        while ((LPC_USB->USBClkSt & CLOCK_MASK) != CLOCK_MASK)
+            ;
+        
+        //    We are a Host
+        LPC_USB->OTGStCtrl |= 1;
+        LPC_USB->USBClkCtrl &= ~PORTSEL_CLK_EN;                // we don't need port selection clock until we do OTG
+        
+        // configure USB pins
+        LPC_PINCON->PINSEL1 &= ~((3<<26)|(3<<28));    
+        LPC_PINCON->PINSEL1 |=    ((1<<26)|(1<<28));            // USB D+/D-
+            
+        LPC_PINCON->PINSEL3 &= ~((3 << 6) | (3 << 22));        // USB_PPWR, USB_OVRCR
+        LPC_PINCON->PINSEL3 |= ((2 << 6) | (2 << 22));
+        
+        LPC_PINCON->PINSEL4 &= ~(3 << 18);                    // USB_CONNECT
+        LPC_PINCON->PINSEL4 |= (1 << 18);
+
+        //    Reset OHCI block
+        LPC_USB->HcControl         = 0;
+        LPC_USB->HcControlHeadED = 0;
+        LPC_USB->HcBulkHeadED     = 0;
+        
+        LPC_USB->HcCommandStatus = HostControllerReset;
+        LPC_USB->HcFmInterval     = DEFAULT_FMINTERVAL;
+        LPC_USB->HcPeriodicStart = FRAMEINTERVAL*90/100;
+
+        LPC_USB->HcControl    = (LPC_USB->HcControl & (~HostControllerFunctionalState)) | OperationalMask;
+        LPC_USB->HcRhStatus = SetGlobalPower;
+        
+        LPC_USB->HcHCCA = (u32)cca;
+        LPC_USB->HcInterruptStatus |= LPC_USB->HcInterruptStatus;
+        LPC_USB->HcInterruptEnable = MasterInterruptEnable | WritebackDoneHead | RootHubStatusChange | FrameNumberOverflow;
+
+        NVIC_SetPriority(USB_IRQn, 0);
+        NVIC_EnableIRQ(USB_IRQn);
+        while (cca->FrameNumber < 10)
+            ;    // 10ms delay before diving in
+    }
+};
+
+//====================================================================================
+//====================================================================================
+//      Host controller instance and Interrupt handler
+
+static HostController _controller __attribute__((at(USB_RAM_BASE)));
+
+extern "C" void USB_IRQHandler(void) __irq;
+void USB_IRQHandler (void) __irq
+{
+    u32 int_status = LPC_USB->HcInterruptStatus;
+
+    if (int_status & RootHubStatusChange)    //    Root hub status change
+        _controller._rootHubStatusChange++;    //    Just flag the controller, will be processed in USBLoop
+
+    u32 head = 0;
+    if (int_status & WritebackDoneHead)
+    {
+        head = _controller.CommunicationArea.DoneHead;        // Writeback Done
+        _controller.CommunicationArea.DoneHead = 0;
+    }             
+//    LPC_USB->HcInterruptStatus = int_status;
+
+    if (head){
+       _controller.ProcessDoneQueue(head & ~1U);     // TODO - low bit can be set BUGBUG
+       if (head & 1) {
+         int othercause = int_status ^ WritebackDoneHead;
+         printf("HcInterruptStatus = %08X\n", int_status);
+       }
+    }
+    else
+      int othercause = int_status;
+    LPC_USB->HcInterruptStatus = int_status;
+//See page 435 of OHCI Specification
+//if the LSb=1 int_status should be checked for other causes
+//if the head=0 there are no TDs on the DoneQueue and int_status should be checked to see what caused this interrupt
+}
+
+//====================================================================================
+//====================================================================================
+//      API Methods
+
+void USBInit()
+{
+    return _controller.Init();
+}
+
+void USBLoop()
+{
+    return _controller.Loop();
+}
+
+u8* USBGetBuffer(u32* len)
+{
+    *len = USB_RAM_SIZE - sizeof(HostController);
+    return _controller.SRAM;
+}
+
+static Setup* GetSetup(int device)
+{
+    if (device == 0)
+        return &_controller._setupZero;
+    
+    if (device < 1 || device > MAX_DEVICES)
+        return 0;
+    return &_controller.Devices[device-1].SetupBuffer;
+}
+
+//    Loop until IO on endpoint is complete
+static int WaitIODone(Endpoint* endpoint)
+{
+    if (endpoint->CurrentState == Endpoint::NotQueued)
+        return 0;
+    while (endpoint->CurrentState != Endpoint::Idle)
+        USBLoop();    // May generate callbacks, mount or unmount devices etc
+    int status = endpoint->Status();
+    if (status == 0)
+        return endpoint->Length;
+    return -status;
+}
+
+int USBTransfer(int device, int ep, u8 flags, u8* data, int length, USBCallback callback, void* userData)
+{
+    Endpoint* endpoint = _controller.GetEndpoint(device,ep);
+    if (!endpoint)
+        return ERR_ENDPOINT_NOT_FOUND;
+        
+    WaitIODone(endpoint);
+    endpoint->Flags = flags;
+    endpoint->Data = data;
+    endpoint->Length = length;
+    endpoint->Callback = callback;
+    endpoint->UserData = userData;
+    if (ep == 0)
+        _controller.Transfer(endpoint,TOKEN_SETUP,(u8*)GetSetup(device),8,Endpoint::SetupQueued);
+    else
+        _controller.Transfer(endpoint,flags & 0x80 ? TOKEN_IN : TOKEN_OUT,data,length,Endpoint::DataQueued);
+    if (callback)
+        return IO_PENDING;
+    return WaitIODone(endpoint);
+}
+
+int USBControlTransfer(int device, int request_type, int request, int value, int index, u8* data, int length, USBCallback callback, void * userData)
+{
+    Setup* setup = GetSetup(device);
+    if (!setup)
+        return ERR_DEVICE_NOT_FOUND;
+        
+    // Async control calls may overwrite setup buffer of previous call, so we need to wait before setting up next call
+    WaitIODone(_controller.GetEndpoint(device,0));
+    
+    setup->bm_request_type = request_type;
+    setup->b_request = request;
+    setup->w_value = value;
+    setup->w_index = index;
+    setup->w_length = length;
+    return USBTransfer(device,0,request_type & DEVICE_TO_HOST,data,length,callback,userData);
+}
+
+int  USBInterruptTransfer(int device, int ep, u8* data, int length, USBCallback callback, void* userData)
+{
+    return USBTransfer(device,ep,(ep & 0x80) | ENDPOINT_INTERRUPT,data,length,callback,userData);
+}
+
+int  USBBulkTransfer(int device, int ep, u8* data, int length, USBCallback callback, void* userData)
+{
+    return USBTransfer(device,ep,(ep & 0x80) | ENDPOINT_BULK,data,length,callback,userData);
+}
+
+int GetDescriptor(int device, int descType,int descIndex, u8* data, int length)
+{
+    return USBControlTransfer(device,DEVICE_TO_HOST | RECIPIENT_DEVICE, GET_DESCRIPTOR,(descType << 8)|(descIndex), 0, data, length, 0);
+}
+
+int GetString(int device, int index, char* dst, int length)
+{
+    u8 buffer[255];
+    int le = GetDescriptor(device,DESCRIPTOR_TYPE_STRING,index,buffer,sizeof(buffer));
+    if (le < 0)
+        return le;
+    if (length < 1)
+        return -1;
+    length <<= 1;
+    if (le > length)
+        le = length;
+    for (int j = 2; j < le; j += 2)
+        *dst++ = buffer[j];
+    *dst = 0;
+    return (le>>1)-1;
+}
+
+int SetAddress(int device, int new_addr)
+{
+    return USBControlTransfer(device,HOST_TO_DEVICE | RECIPIENT_DEVICE, SET_ADDRESS, new_addr, 0, 0, 0, 0);
+}
+
+int SetConfiguration(int device, int configNum)
+{
+    return USBControlTransfer(device,HOST_TO_DEVICE | RECIPIENT_DEVICE, SET_CONFIGURATION, configNum, 0, 0, 0, 0);
+}
+
+int SetInterface(int device, int ifNum, int altNum)
+{
+    return USBControlTransfer(device,HOST_TO_DEVICE | RECIPIENT_INTERFACE, SET_INTERFACE, altNum, ifNum, 0, 0, 0);
+}
+
+//    HUB stuff
+int SetPortFeature(int device, int feature, int index)
+{
+    return USBControlTransfer(device,HOST_TO_DEVICE | REQUEST_TYPE_CLASS | RECIPIENT_OTHER,SET_FEATURE,feature,index,0,0);
+}
+
+int ClearPortFeature(int device, int feature, int index)
+{
+    return USBControlTransfer(device,HOST_TO_DEVICE | REQUEST_TYPE_CLASS | RECIPIENT_OTHER,CLEAR_FEATURE,feature,index,0,0);
+}
+
+int SetPortPower(int device, int port)
+{
+    int r = SetPortFeature(device,PORT_POWER,port);
+    _controller.DelayMS(20);    // 80ms to turn on a hubs power... DESCRIPTOR? todo
+    return r;
+}
+
+int SetPortReset(int device, int port)
+{
+    return SetPortFeature(device,PORT_RESET,port);
+}
+
+int GetPortStatus(int device, int port, u32* status)
+{
+    return USBControlTransfer(device,DEVICE_TO_HOST | REQUEST_TYPE_CLASS | RECIPIENT_OTHER,GET_STATUS,0,port,(u8*)status,4);
+}
\ No newline at end of file