/* The request_func_table[] is a table of all USB request handling functions.
 * Every entry in this table must have a corresponding index in the
 * request_function_index enumerated type list.
 */
const void (* request_func_table[])(void) =
{
   USB_send_stall,
   ClearRemoteWakeup, SetRemoteWakeup, SetAddress, SetConfiguration,
   ClearEndpointStall, SetEndpointStall,
   GetDeviceStatus, GetDescriptor, GetConfiguration,
   GetInterfaceStatus,
   GetEndpointStatus,
   SetReport, SetIdle, SetProtocol,
   GetReport, GetIdle, GetProtocol
};

enum request_function_index 
{
  USB_send_stall_index,
  ClearRemoteWakeup_index, SetRemoteWakeup_index, SetAddress_index, SetConfiguration_index,
  ClearEndpointStall_index, SetEndpointStall_index,
  GetDeviceStatus_index, GetDescriptor_index, GetConfiguration_index,
  GetInterfaceStatus_index,
  GetEndpointStatus_index,
  SetReport_index, SetIdle_index, SetProtocol_index,
  GetReport_index, GetIdle_index, GetProtocol_index
};

enum request_function_index function_index;

char far * table_ptr;

/* The USB_request_table[] array has a table entry for every USB request handle by this application.
 * Each entry consists of a request type, a request and an index into the request_func_table[]
 */ 
const char USB_request_table[] = 
{
  HOST_TO_DEVICE | STANDARD | DEVICE       , USB_CLEAR_FEATURE    , ClearRemoteWakeup_index , /* 00 01 */
  HOST_TO_DEVICE | STANDARD | DEVICE       , USB_SET_FEATURE      , SetRemoteWakeup_index   , /* 00 03 */
  HOST_TO_DEVICE | STANDARD | DEVICE       , USB_SET_ADDRESS      , SetAddress_index        , /* 00 05 */
  HOST_TO_DEVICE | STANDARD | DEVICE       , USB_SET_CONFIGURATION, SetConfiguration_index  , /* 00 09 */
  HOST_TO_DEVICE | STANDARD | ENDPOINT     , USB_CLEAR_FEATURE    , ClearEndpointStall_index, /* 02 01 */
  HOST_TO_DEVICE | STANDARD | ENDPOINT     , USB_SET_FEATURE      , SetEndpointStall_index  , /* 02 03 */
  DEVICE_TO_HOST | STANDARD | DEVICE       , USB_GET_STATUS       , GetDeviceStatus_index   , /* 80 00 */
  DEVICE_TO_HOST | STANDARD | DEVICE       , USB_GET_DESCRIPTOR   , GetDescriptor_index     , /* 80 06 */
  DEVICE_TO_HOST | STANDARD | DEVICE       , USB_GET_CONFIGURATION, GetConfiguration_index  , /* 80 08 */
  DEVICE_TO_HOST | STANDARD | INTERFACE    , USB_GET_STATUS       , GetInterfaceStatus_index, /* 81 00 */
  DEVICE_TO_HOST | STANDARD | INTERFACE    , USB_GET_DESCRIPTOR   , GetDescriptor_index     , /* 81 06 */
  DEVICE_TO_HOST | STANDARD | ENDPOINT     , USB_GET_STATUS       , GetEndpointStatus_index , /* 82 00 */
  DEVICE_TO_HOST | STANDARD | ENDPOINT     , USB_GET_DESCRIPTOR   , GetDescriptor_index     , /* 82 06 */
  HOST_TO_DEVICE | CLASS    | INTERFACE    , USB_SET_REPORT       , SetReport_index         , /* 21 09 */
  HOST_TO_DEVICE | CLASS    | INTERFACE    , USB_SET_IDLE         , SetIdle_index           , /* 21 0A */
  HOST_TO_DEVICE | CLASS    | INTERFACE    , USB_SET_PROTOCOL     , SetProtocol_index       , /* 21 0B */
  HOST_TO_DEVICE | CLASS    | ENDPOINT     , USB_SET_REPORT       , SetReport_index         , /* 22 09 */
  HOST_TO_DEVICE | CLASS    | ENDPOINT     , USB_SET_IDLE         , SetIdle_index           , /* 22 0A */
  HOST_TO_DEVICE | CLASS    | ENDPOINT     , USB_SET_PROTOCOL     , SetProtocol_index       , /* 22 0B */
  DEVICE_TO_HOST | CLASS    | INTERFACE    , USB_GET_REPORT       , GetReport_index         , /* A1 01 */
  DEVICE_TO_HOST | CLASS    | INTERFACE    , USB_GET_IDLE         , GetIdle_index           , /* A1 02 */
  DEVICE_TO_HOST | CLASS    | INTERFACE    , USB_GET_PROTOCOL     , GetProtocol_index         /* A1 03 */
};

void USB_request_handler(void)
{
    table_ptr = USB_request_table; /* reset table pointer to start of request table */
    function_index = USB_send_stall_index; /* default to 'stall' function if request if not found */
    do
    {
        if( *table_ptr == ENDPOINT_A0_FIFO[USB_bmRequestType] ) /* check for request type */
        {
            if( *(table_ptr+1) == ENDPOINT_A0_FIFO[USB_bRequest] ) /* check for request */
                function_index = *(table_ptr+2); /* get the function index for the request handler */
        }
        table_ptr += 3;
    }
    while( table_ptr < (USB_request_table + sizeof(USB_request_table)) ); /* find the index for the function handler */ 
    (*request_func_table[function_index])(); /* call function handler for USB request */
}