KernelLand/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   0
   9 #include <usb_core.h>
  10 #include "usb.h"
  11 #include <timers.h>
  12
  13 #define POLL_ATOM       25      // 25ms atom
  14 #define POLL_MAX        256     // Max period that can be nominated
  15 #define POLL_SLOTS      ((int)(POLL_MAX/POLL_ATOM))
  16
  17 // === IMPORTS ===
  18 extern tUSBHost *gUSB_Hosts;
  19
  20 // === PROTOTYPES ===
  21 void    USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint);
  22
  23 // === GLOBALS ===
  24 tUSBEndpoint    *gUSB_PollQueues[POLL_MAX/POLL_ATOM];
  25  int    giUSB_PollPosition;     // Index into gUSB_PollQueues
  26
  27 // === CODE ===
  28 void USB_StartPollingEndpoint(tUSBInterface *Iface, int Endpoint)
  29 {
  30         tUSBEndpoint    *endpt;
  31
  32         ENTER("pIface iEndpoint", Iface, Endpoint);
  33         LEAVE('-');
  34
  35         // Some sanity checks
  36         if(Endpoint <= 0 || Endpoint > Iface->nEndpoints)
  37                 return ;
  38         endpt = &Iface->Endpoints[Endpoint-1];
  39         LOG("endpt(%p)->PollingPeriod = %i", endpt, endpt->PollingPeriod);
  40         if(endpt->PollingPeriod > POLL_MAX || endpt->PollingPeriod <= 0)
  41                 return ;
  42
  43         // TODO: Check that this endpoint isn't already on the queue
  44
  45         endpt->InputData = malloc(endpt->MaxPacketSize);
  46
  47         // Determine polling period in atoms
  48         endpt->PollingAtoms = (endpt->PollingPeriod + POLL_ATOM-1) / POLL_ATOM;
  49         if(endpt->PollingAtoms > POLL_SLOTS)    endpt->PollingAtoms = POLL_SLOTS;
  50         LOG("endpt(%p)->PollingAtoms = %i", endpt, endpt->PollingAtoms);
  51         // Add to poll queue
  52         // TODO: Locking
  53         {
  54                  int    idx = giUSB_PollPosition + 1;
  55                 if(idx >= POLL_SLOTS)   idx -= POLL_SLOTS;
  56                 endpt->Next = gUSB_PollQueues[idx];
  57                 gUSB_PollQueues[idx] = endpt;
  58         }
  59 }
  60
  61 /**
  62  * \brief USB polling thread
  63  */
  64 int USB_PollThread(void *unused)
  65 {
  66         Threads_SetName("USB Polling Thread");
  67         for(;;)
  68         {
  69                 tUSBEndpoint    *ep, *prev;
  70
  71                 if(giUSB_PollPosition == 0)
  72                 {
  73                         // Check hosts
  74                         for( tUSBHost *host = gUSB_Hosts; host; host = host->Next )
  75                         {
  76                                 host->HostDef->CheckPorts(host->Ptr);
  77                         }
  78                 }
  79
  80 //              Log_Debug("USBPoll", "giUSB_PollPosition = %i", giUSB_PollPosition);
  81
  82                 // A little evil for neater code
  83                 prev = (void*)( (tVAddr)&gUSB_PollQueues[giUSB_PollPosition] - offsetof(tUSBEndpoint, Next) );
  84
  85                 // Process queue
  86 //              LOG("giUSB_PollPosition = %i", giUSB_PollPosition);
  87                 for( ep = gUSB_PollQueues[giUSB_PollPosition]; ep; prev = ep, ep = ep->Next )
  88                 {
  89                          int    period_in_atoms = ep->PollingAtoms;
  90                         LOG("%i: ep = %p", giUSB_PollPosition, ep);
  91
  92                         // Check for invalid entries
  93                         if(period_in_atoms < 0 || period_in_atoms > POLL_ATOM)
  94                         {
  95                                 Log_Warning("USB", "Endpoint on polling queue with invalid period");
  96                                 continue ;
  97                         }
  98                         // Check for entries to delete
  99                         if(period_in_atoms == 0)
 100                         {
 101                                 // Remove
 102                                 prev->Next = ep->Next;
 103                                 ep->PollingAtoms = -1;  // Mark as removed
 104                                 ep = prev;      // Make sure prev is kept valid
 105                                 continue ;
 106                         }
 107
 108                         // Read data
 109                         // TODO: Check the endpoint
 110                         // TODO: Async checking?
 111                         // - Send the read request on all of them then wait for the first to complete
 112                         USB_RecvDataA(
 113                                 ep->Interface, ep->EndpointIdx+1,
 114                                 ep->MaxPacketSize, ep->InputData,
 115                                 ep->Interface->Driver->Endpoints[ep->EndpointIdx].DataAvail
 116                                 );
 117
 118                         // Call callback
 119
 120                         // Reschedule
 121                         if( period_in_atoms != POLL_SLOTS )
 122                         {
 123                                  int    newqueue_id = (giUSB_PollPosition + period_in_atoms) % POLL_SLOTS;
 124                                 tUSBEndpoint    **newqueue = &gUSB_PollQueues[newqueue_id];
 125
 126                                 prev->Next = ep->Next;
 127
 128                                 ep->Next = *newqueue;
 129                                 *newqueue = ep;
 130                                 ep = prev;
 131                         }
 132                 }
 133                 giUSB_PollPosition ++;
 134                 if(giUSB_PollPosition == POLL_SLOTS)
 135                         giUSB_PollPosition = 0;
 136                 // TODO: Check for a longer delay
 137                 Time_Delay(POLL_ATOM);
 138         }
 139 }
 140