git.rot13.org Git - goodfet/blob - client/USBEndpoint.py

   1 # USBEndpoint.py
   2 #
   3 # Contains class definition for USBEndpoint.
   4
   5 class USBEndpoint:
   6     direction_out               = 0x00
   7     direction_in                = 0x01
   8
   9     transfer_type_control       = 0x00
  10     transfer_type_isochronous   = 0x01
  11     transfer_type_bulk          = 0x02
  12     transfer_type_interrupt     = 0x03
  13
  14     sync_type_none              = 0x00
  15     sync_type_async             = 0x01
  16     sync_type_adaptive          = 0x02
  17     sync_type_synchronous       = 0x03
  18
  19     usage_type_data             = 0x00
  20     usage_type_feedback         = 0x01
  21     usage_type_implicit_feedback = 0x02
  22
  23     def __init__(self, number, direction, transfer_type, sync_type,
  24             usage_type, max_packet_size, interval, handler):
  25
  26         self.number             = number
  27         self.direction          = direction
  28         self.transfer_type      = transfer_type
  29         self.sync_type          = sync_type
  30         self.usage_type         = usage_type
  31         self.max_packet_size    = max_packet_size
  32         self.interval           = interval
  33         self.handler            = handler
  34
  35     # see Table 9-13 of USB 2.0 spec (pdf page 297)
  36     def get_descriptor(self):
  37         address = (self.number & 0x0f) | (self.direction << 7)
  38         attributes = (self.transfer_type & 0x03) \
  39                    | ((self.sync_type & 0x03) << 2) \
  40                    | ((self.usage_type & 0x03) << 4)
  41
  42         d = bytearray([
  43                 7,          # length of descriptor in bytes
  44                 5,          # descriptor type 5 == endpoint
  45                 address,
  46                 attributes,
  47                 (self.max_packet_size >> 8) & 0xff,
  48                 self.max_packet_size & 0xff,
  49                 self.interval
  50         ])
  51
  52         return d
  53