Modules/USB/Core/usb_poll.c

   1 /*
   2  * Acess2 USB Stack
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * usb_poll.c
   6  * - Endpoint polling
   7  */
   8 #define DEBUG   1
   9 #include <usb_core.h>
  10 #include "usb.h"
  11
  12 #define POLL_ATOM       25      // 25ms atom
  13 #define POLL_MAX        256     // Max period that can be nominated
  14 #define POLL_SLOTS      ((int)(POLL_MAX/POLL_ATOM))
  15
  16 // === IMPORTS ===
  17 extern tUSBHost *gUSB_Hosts;
  18
  19 // === PROTOTYPES ===
  20 void    USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint);
  21
  22 // === GLOBALS ===
  23 tUSBEndpoint    *gUSB_PollQueues[POLL_MAX/POLL_ATOM];
  24  int    giUSB_PollPosition;     // Index into gUSB_PollQueues
  25
  26 // === CODE ===
  27 void USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint)
  28 {
  29         tUSBEndpoint    *endpt;
  30
  31         // Some sanity checks
  32         if(Endpoint <= 0 || Endpoint > Iface->nEndpoints)       return ;
  33         endpt = &Iface->Endpoints[Endpoint-1];
  34         if(endpt->PollingPeriod > POLL_MAX || endpt->PollingPeriod <= 0)
  35                 return ;
  36
  37         // TODO: Check that this endpoint isn't already on the queue
  38
  39         endpt->InputData = malloc(endpt->MaxPacketSize);
  40
  41         // Determine polling period in atoms
  42         endpt->PollingAtoms = (endpt->PollingPeriod + POLL_ATOM-1) / POLL_ATOM;
  43         if(endpt->PollingAtoms > POLL_SLOTS)    endpt->PollingAtoms = POLL_SLOTS;
  44         // Add to poll queue
  45         // TODO: Locking
  46         {
  47                  int    idx = giUSB_PollPosition + 1;
  48                 if(idx >= POLL_SLOTS)   idx -= POLL_SLOTS;
  49                 endpt->Next = gUSB_PollQueues[idx];
  50                 gUSB_PollQueues[idx] = endpt;
  51         }
  52 }
  53
  54 /**
  55  * \brief USB polling thread
  56  */
  57 int USB_PollThread(void *unused)
  58 {
  59         Threads_SetName("USB Polling Thread");
  60         for(;;)
  61         {
  62                 tUSBEndpoint    *ep, *prev;
  63
  64                 if(giUSB_PollPosition == 0)
  65                 {
  66                         // Check hosts
  67                         for( tUSBHost *host = gUSB_Hosts; host; host = host->Next )
  68                         {
  69                                 host->HostDef->CheckPorts(host->Ptr);
  70                         }
  71                 }
  72
  73 //              Log_Debug("USBPoll", "giUSB_PollPosition = %i", giUSB_PollPosition);
  74
  75                 // A little evil for neater code
  76                 prev = (void*)( (tVAddr)&gUSB_PollQueues[giUSB_PollPosition] - offsetof(tUSBEndpoint, Next) );
  77
  78                 // Process queue
  79 //              LOG("giUSB_PollPosition = %i", giUSB_PollPosition);
  80                 for( ep = gUSB_PollQueues[giUSB_PollPosition]; ep; prev = ep, ep = ep->Next )
  81                 {
  82                          int    period_in_atoms = ep->PollingAtoms;
  83 //                      LOG("%i: ep = %p", giUSB_PollPosition, ep);
  84
  85                         // Check for invalid entries
  86                         if(period_in_atoms < 0 || period_in_atoms > POLL_ATOM)
  87                         {
  88                                 Log_Warning("USB", "Endpoint on polling queue with invalid period");
  89                                 continue ;
  90                         }
  91                         // Check for entries to delete
  92                         if(period_in_atoms == 0)
  93                         {
  94                                 // Remove
  95                                 prev->Next = ep->Next;
  96                                 ep->PollingAtoms = -1;  // Mark as removed
  97                                 ep = prev;      // Make sure prev is kept valid
  98                                 continue ;
  99                         }
 100
 101                         // Read data
 102                         // TODO: Check the endpoint
 103                         // TODO: Async checking?
 104                         // - Send the read request on all of them then wait for the first to complete
 105                         USB_RecvDataA(
 106                                 ep->Interface, ep->EndpointIdx+1,
 107                                 ep->MaxPacketSize, ep->InputData,
 108                                 ep->Interface->Driver->Endpoints[ep->EndpointIdx].DataAvail
 109                                 );
 110
 111                         // Call callback
 112
 113                         // Reschedule
 114                         if( period_in_atoms != POLL_SLOTS )
 115                         {
 116                                  int    newqueue_id = (giUSB_PollPosition + period_in_atoms) % POLL_SLOTS;
 117                                 tUSBEndpoint    **newqueue = &gUSB_PollQueues[newqueue_id];
 118
 119                                 prev->Next = ep->Next;
 120
 121                                 ep->Next = *newqueue;
 122                                 *newqueue = ep;
 123                                 ep = prev;
 124                         }
 125                 }
 126                 giUSB_PollPosition ++;
 127                 if(giUSB_PollPosition == POLL_SLOTS)
 128                         giUSB_PollPosition = 0;
 129                 // TODO: Check for a longer delay
 130                 Time_Delay(POLL_ATOM);
 131         }
 132 }
 133