LUFA/Drivers/USB/LowLevel/OTG.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Macros for embedded USB hosts with dual role On The Go capabilities, for managing role exchange. OTG
  34  *  is a way for two USB dual role devices to talk to one another directly without fixed device/host roles.
  35  *
  36  *  \note These macros are only for AVRs which support the OTG protocol, and do not exist for device-only AVRs.
  37  */
  38
  39 #ifndef __USBOTG_H__
  40 #define __USBOTG_H__
  41
  42         /* Includes: */
  43                 #include <avr/io.h>
  44                 #include <stdbool.h>
  45
  46                 #include "../../../Common/Common.h"
  47
  48         /* Public Interface - May be used in end-application: */
  49                 /* Macros: */
  50                         /** Initiate a Host Negotiation Protocol request. This indicates to the other connected device
  51                          *  that the device wishes to change device/host roles.
  52                          */
  53                         #define USB_OTG_DEV_Request_HNP()          MACROS{ OTGCON |=  (1 << HNPREQ); }MACROE
  54
  55                         /** Cancel a Host Negotiation Protocol request. This stops a pending HNP request to the other
  56                          *  connected device.
  57                          */
  58                         #define USB_OTG_DEV_Cancel_HNP_Request()   MACROS{ OTGCON &= ~(1 << HNPREQ); }MACROE
  59
  60                         /** Returns boolean false if not currently sending a HNP to the other connected device, or true
  61                          *  if a HNP is currently being issued.
  62                          */
  63                         #define USB_OTG_DEV_IsSendingHNP()               ((OTGCON &   (1 << HNPREQ)) ? true : false)
  64
  65                         /** Accepts a HNP from a connected device, indicating that both devices should exchange
  66                          *  device/host roles.
  67                          */
  68                         #define USB_OTG_HOST_Accept_HNP()          USB_OTG_DEV_Request_HNP()
  69
  70                         /** Rejects a HNP from a connected device, indicating that both devices should remain in their
  71                          *  current device/host roles.
  72                          */
  73                         #define USB_OTG_HOST_Reject_HNP()          USB_OTG_DEV_Cancel_HNP_Request()
  74
  75                         /** Returns boolean false if the connected device is not currently sending a HNP request, or true
  76                          *  if a HNP is currently being issued by the connected device.
  77                          */
  78                         #define USB_OTG_HOST_IsHNPReceived()             ((OTGCON &   (1 << HNPREQ)) ? true : false)
  79
  80                         /** Initiates a Session Request Protocol request. Most OTG devices turn off VBUS when the USB
  81                          *  interface is not in use, to conserve power. Sending a SRP to a USB OTG device running in
  82                          *  host mode indicates that VBUS should be applied and a session started.
  83                          *
  84                          *  There are two different methods of sending a SRP - either pulses on the VBUS line, or by
  85                          *  pulsing the Data + line via the internal pull-up resistor. The SRP mode is given as the
  86                          *  "type" parameter, and can be either USB_OTG_SRP_VBUS or USB_OTG_STP_DATA.
  87                          */
  88                         #define USB_OTG_DEV_Initiate_SRP(type)     MACROS{ OTGCON = ((OTGCON & ~(1 << SRPSEL)) | (type | (1 << SRPREQ))); }MACROE
  89
  90                         /** Mask for the VBUS pulsing method of SRP, supported by some OTG devices.
  91                          *
  92                          *  \see USB_OTG_DEV_Initiate_SRP()
  93                          */
  94                         #define USB_OTG_SRP_VBUS                   (1 << SRPSEL)
  95
  96                         /** Mask for the Data + pulsing method of SRP, supported by some OTG devices.
  97                          *
  98                          *  \see USB_OTG_DEV_Initiate_SRP()
  99                          */
 100                         #define USB_OTG_STP_DATA                   0
 101
 102 #endif