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 /** \ingroup Group_USB
  40  *  @defgroup Group_OTGManagement USB On The Go (OTG) Management
  41  *
  42  *  Functions, macros, variables, enums and types related to the setup and management of dual role devices.
  43  *
  44  *  @{
  45  */
  46
  47 #ifndef __USBOTG_H__
  48 #define __USBOTG_H__
  49
  50         /* Includes: */
  51                 #include <avr/io.h>
  52                 #include <stdbool.h>
  53
  54                 #include "../../../Common/Common.h"
  55
  56         /* Public Interface - May be used in end-application: */
  57                 /* Macros: */
  58                         /** Mask for the VBUS pulsing method of SRP, supported by some OTG devices.
  59                          *
  60                          *  \see USB_OTG_DEV_Initiate_SRP()
  61                          */
  62                         #define USB_OTG_SRP_VBUS                   (1 << SRPSEL)
  63
  64                         /** Mask for the Data + pulsing method of SRP, supported by some OTG devices.
  65                          *
  66                          *  \see USB_OTG_DEV_Initiate_SRP()
  67                          */
  68                         #define USB_OTG_STP_DATA                   0
  69
  70                 /* Psuedo-Function Macros: */
  71                         #if defined(__DOXYGEN__)
  72                                 /** Initiate a Host Negotiation Protocol request. This indicates to the other connected device
  73                                  *  that the device wishes to change device/host roles.
  74                                  */
  75                                 static inline void USB_OTG_DEV_Request_HNP(void);
  76
  77                                 /** Cancel a Host Negotiation Protocol request. This stops a pending HNP request to the other
  78                                  *  connected device.
  79                                  */
  80                                 static inline void USB_OTG_DEV_Cancel_HNP_Request(void);
  81
  82                                 /** Determines if the device is currently sending a HNP to an attached host.
  83                                  *
  84                                  *  \return Boolean true if currently sending a HNP to the other connected device, false otherwise
  85                                  */
  86                                 static inline bool USB_OTG_DEV_IsSendingHNP(void);
  87
  88                                 /** Accepts a HNP from a connected device, indicating that both devices should exchange
  89                                  *  device/host roles.
  90                                  */
  91                                 static inline void USB_OTG_HOST_Accept_HNP(void);
  92
  93                                 /** Rejects a HNP from a connected device, indicating that both devices should remain in their
  94                                  *  current device/host roles.
  95                                  */
  96                                 static inline void USB_OTG_HOST_Reject_HNP(void);
  97
  98                                 /** Indicates if the connected device is not currently sending a HNP request.
  99                                  *
 100                                  *  \return Boolean true if a HNP is currently being issued by the connected device, false otherwise.
 101                                  */
 102                                 static inline bool USB_OTG_HOST_IsHNPReceived(void);
 103
 104                                 /** Initiates a Session Request Protocol request. Most OTG devices turn off VBUS when the USB
 105                                  *  interface is not in use, to conserve power. Sending a SRP to a USB OTG device running in
 106                                  *  host mode indicates that VBUS should be applied and a session started.
 107                                  *
 108                                  *  There are two different methods of sending a SRP - either pulses on the VBUS line, or by
 109                                  *  pulsing the Data + line via the internal pull-up resistor.
 110                                  *
 111                                  *  \param SRPTypeMask  Mask indicating the type of SRP to use, either USB_OTG_SRP_VBUS or USB_OTG_STP_DATA.
 112                                  */
 113                                 static inline void USB_OTG_DEV_Initiate_SRP(uint8_t SRPTypeMask);
 114                         #else
 115
 116                                 #define USB_OTG_DEV_Request_HNP()          MACROS{ OTGCON |=  (1 << HNPREQ); }MACROE
 117
 118                                 #define USB_OTG_DEV_Cancel_HNP_Request()   MACROS{ OTGCON &= ~(1 << HNPREQ); }MACROE
 119
 120                                 #define USB_OTG_DEV_IsSendingHNP()               ((OTGCON &   (1 << HNPREQ)) ? true : false)
 121
 122                                 #define USB_OTG_HOST_Accept_HNP()          MACROS{ OTGCON |=  (1 << HNPREQ); }MACROE
 123
 124                                 #define USB_OTG_HOST_Reject_HNP()         MACROS{ OTGCON &= ~(1 << HNPREQ); }MACROE
 125
 126                                 #define USB_OTG_HOST_IsHNPReceived()             ((OTGCON &   (1 << HNPREQ)) ? true : false)
 127
 128                                 #define USB_OTG_DEV_Initiate_SRP(type)     MACROS{ OTGCON = ((OTGCON & ~(1 << SRPSEL)) | (type | (1 << SRPREQ))); }MACROE
 129                         #endif
 130
 131 #endif
 132
 133 /** @} */