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 /** \ingroup Group_USB
  32  *  @defgroup Group_OTGManagement USB On The Go (OTG) Management
  33  *
  34  *  This module contains macros for embedded USB hosts with dual role On The Go capabilities, for managing role
  35  *  exchange. OTG is a way for two USB dual role devices to talk to one another directly without fixed device/host
  36  *  roles.
  37  *
  38  *  @{
  39  */
  40
  41 #ifndef __USBOTG_H__
  42 #define __USBOTG_H__
  43
  44         /* Includes: */
  45                 #include <avr/io.h>
  46                 #include <stdbool.h>
  47
  48                 #include "../../../Common/Common.h"
  49
  50         /* Public Interface - May be used in end-application: */
  51                 /* Macros: */
  52                         /** Mask for the VBUS pulsing method of SRP, supported by some OTG devices.
  53                          *
  54                          *  \see USB_OTG_DEV_Initiate_SRP()
  55                          */
  56                         #define USB_OTG_SRP_VBUS                   (1 << SRPSEL)
  57
  58                         /** Mask for the Data + pulsing method of SRP, supported by some OTG devices.
  59                          *
  60                          *  \see USB_OTG_DEV_Initiate_SRP()
  61                          */
  62                         #define USB_OTG_STP_DATA                   0
  63
  64                 /* Pseudo-Function Macros: */
  65                         #if defined(__DOXYGEN__)
  66                                 /** Initiate a Host Negotiation Protocol request. This indicates to the other connected device
  67                                  *  that the device wishes to change device/host roles.
  68                                  */
  69                                 static inline void USB_OTG_DEV_Request_HNP(void);
  70
  71                                 /** Cancel a Host Negotiation Protocol request. This stops a pending HNP request to the other
  72                                  *  connected device.
  73                                  */
  74                                 static inline void USB_OTG_DEV_Cancel_HNP_Request(void);
  75
  76                                 /** Determines if the device is currently sending a HNP to an attached host.
  77                                  *
  78                                  *  \return Boolean true if currently sending a HNP to the other connected device, false otherwise
  79                                  */
  80                                 static inline bool USB_OTG_DEV_IsSendingHNP(void);
  81
  82                                 /** Accepts a HNP from a connected device, indicating that both devices should exchange
  83                                  *  device/host roles.
  84                                  */
  85                                 static inline void USB_OTG_HOST_Accept_HNP(void);
  86
  87                                 /** Rejects a HNP from a connected device, indicating that both devices should remain in their
  88                                  *  current device/host roles.
  89                                  */
  90                                 static inline void USB_OTG_HOST_Reject_HNP(void);
  91
  92                                 /** Indicates if the connected device is not currently sending a HNP request.
  93                                  *
  94                                  *  \return Boolean true if a HNP is currently being issued by the connected device, false otherwise.
  95                                  */
  96                                 static inline bool USB_OTG_HOST_IsHNPReceived(void);
  97
  98                                 /** Initiates a Session Request Protocol request. Most OTG devices turn off VBUS when the USB
  99                                  *  interface is not in use, to conserve power. Sending a SRP to a USB OTG device running in
 100                                  *  host mode indicates that VBUS should be applied and a session started.
 101                                  *
 102                                  *  There are two different methods of sending a SRP - either pulses on the VBUS line, or by
 103                                  *  pulsing the Data + line via the internal pull-up resistor.
 104                                  *
 105                                  *  \param SRPTypeMask  Mask indicating the type of SRP to use, either USB_OTG_SRP_VBUS or USB_OTG_STP_DATA.
 106                                  */
 107                                 static inline void USB_OTG_DEV_Initiate_SRP(uint8_t SRPTypeMask);
 108                         #else
 109
 110                                 #define USB_OTG_DEV_Request_HNP()          MACROS{ OTGCON |=  (1 << HNPREQ); }MACROE
 111
 112                                 #define USB_OTG_DEV_Cancel_HNP_Request()   MACROS{ OTGCON &= ~(1 << HNPREQ); }MACROE
 113
 114                                 #define USB_OTG_DEV_IsSendingHNP()               ((OTGCON &   (1 << HNPREQ)) ? true : false)
 115
 116                                 #define USB_OTG_HOST_Accept_HNP()          MACROS{ OTGCON |=  (1 << HNPREQ); }MACROE
 117
 118                                 #define USB_OTG_HOST_Reject_HNP()         MACROS{ OTGCON &= ~(1 << HNPREQ); }MACROE
 119
 120                                 #define USB_OTG_HOST_IsHNPReceived()             ((OTGCON &   (1 << HNPREQ)) ? true : false)
 121
 122                                 #define USB_OTG_DEV_Initiate_SRP(type)     MACROS{ OTGCON = ((OTGCON & ~(1 << SRPSEL)) | (type | (1 << SRPREQ))); }MACROE
 123                         #endif
 124
 125 #endif
 126
 127 /** @} */