LUFA/Drivers/USB/HighLevel/USBTask.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  *  Main library USB management task for both Host and Device mode operations. This contains the master
  34  *  USB_USBTask task which should be periodically run to service both host and device USB projects.
  35  */
  36
  37 #ifndef __USBTASK_H__
  38 #define __USBTASK_H__
  39
  40         /* Includes: */
  41                 #include <avr/io.h>
  42                 #include <avr/interrupt.h>
  43                 #include <util/atomic.h>
  44                 #include <stdbool.h>
  45                 #include <stddef.h>
  46
  47                 #include "../../../Scheduler/Scheduler.h"
  48                 #include "../LowLevel/LowLevel.h"
  49                 #include "USBMode.h"
  50                 #include "Events.h"
  51                 #include "StdDescriptors.h"
  52
  53                 #if defined(USB_CAN_BE_HOST)
  54                         #include "../LowLevel/HostChapter9.h"
  55                 #endif
  56
  57         /* Enable C linkage for C++ Compilers: */
  58                 #if defined(__cplusplus)
  59                         extern "C" {
  60                 #endif
  61
  62         /* Public Interface - May be used in end-application: */
  63                 /* Global Variables: */
  64                         /** Indicates if the USB interface is currently connected to a host if in device mode, or to a
  65                          *  device while running in host mode.
  66                          *
  67                          *  \note This variable should be treated as read-only in the user application, and never manually
  68                          *        changed in value.
  69                          *
  70                          *  \note For the smaller USB AVRs (AT90USBXX2) with limited USB controllers, VBUS is not available to the USB controller.
  71                          *        this means that the current connection state is derived from the bus suspension and wake up events by default,
  72                          *        which is not always accurate (host may suspend the bus while still connected). If the actual connection state
  73                          *        needs to be determined, VBUS should be routed to an external pin, and the auto-detect behaviour turned off by
  74                          *        passing the NO_LIMITED_CONTROLLER_CONNECT token to the compiler via the -D switch at compile time. The connection
  75                          *        and disconnection events may be manually fired by RAISE_EVENT(), and the USB_IsConnected global changed manually.
  76                          */
  77                         extern volatile bool USB_IsConnected;
  78
  79                         /** Indicates if the USB interface is currently initialized but not necessarily connected to a host
  80                          *  or device (i.e. if USB_Init() has been run). If this is false, all other library globals are invalid.
  81                          *
  82                          *  \note This variable should be treated as read-only in the user application, and never manually
  83                          *        changed in value.
  84                          */
  85                         extern volatile bool USB_IsInitialized;
  86
  87                         #if defined(USB_CAN_BE_DEVICE) || defined(__DOXYGEN__)
  88                         /** Indicates if the USB interface is currently suspended by the host when in device mode. When suspended,
  89                          *  the device should consume minimal power, and cannot communicate to the host. If Remote Wakeup is
  90                          *  supported by the device and USB_RemoteWakeupEnabled is true, suspension can be terminated by the device
  91                          *  by issuing a Remote Wakup request.
  92                          *
  93                          *  \note This global is only present if the user application can be a USB device.
  94                          *
  95                          *  \note This variable should be treated as read-only in the user application, and never manually
  96                          *        changed in value.
  97                          */
  98                         extern volatile bool USB_IsSuspended;
  99                         #endif
 100
 101                         #if defined(USB_CAN_BE_HOST) || defined(__DOXYGEN__)
 102                         /** Indicates the current host state machine state. When in host mode, this indicates the state
 103                          *  via one of the values of the USB_Host_States_t enum values in Host.h.
 104                          *
 105                          *  This value may be altered by the user application to implement the HOST_STATE_Addressed,
 106                          *  HOST_STATE_Configured, HOST_STATE_Ready and HOST_STATE_Suspended states which are not implemented
 107                          *  by the library.
 108                          *
 109                          *  \note This global is only present if the user application can be a USB host.
 110                          */
 111                         extern volatile uint8_t USB_HostState;
 112                         #endif
 113
 114                 /* Throwable Events: */
 115                         #if defined(USB_CAN_BE_HOST) || defined(__DOXYGEN__)
 116                                 /** This module raises the USB Connect event when a USB device has been connected whilst in host
 117                                  *  mode, but not yet enumerated.
 118                                  *
 119                                  *  \see Events.h for more information on this event.
 120                                  */
 121                                 RAISES_EVENT(USB_Connect);
 122
 123                                 /** This module raises the USB Device Attached event when in host mode, and a device is attached
 124                                  *  to the AVR's USB interface.
 125                                  *
 126                                  *  \see Events.h for more information on this event.
 127                                  */
 128                                 RAISES_EVENT(USB_DeviceAttached);
 129
 130                                 /** This module raises the USB Device Unattached event when in host mode, and a device is removed
 131                                  *  from the AVR's USB interface.
 132                                  *
 133                                  *  \see Events.h for more information on this event.
 134                                  */
 135                                 RAISES_EVENT(USB_DeviceUnattached);
 136
 137                                 /** This module raises the USB Device Enumeration Failed event when in host mode, and an
 138                                  *  attached USB device has failed to successfully enumerated.
 139                                  *
 140                                  *  \see Events.h for more information on this event.
 141                                  */
 142                                 RAISES_EVENT(USB_DeviceEnumerationFailed);
 143
 144                                 /** This module raises the USB Device Enumeration Complete event when in host mode, and an
 145                                  *  attached USB device has been successfully enumerated and ready to be used by the user
 146                                  *  application.
 147                                  *
 148                                  *  \see Events.h for more information on this event.
 149                                  */
 150                                 RAISES_EVENT(USB_DeviceEnumerationComplete);
 151
 152                                 /** This module raises the USB Disconnect event when an attached USB device is removed from the USB
 153                                  *  bus.
 154                                  *
 155                                  *  \see Events.h for more information on this event.
 156                                  */
 157                                 RAISES_EVENT(USB_Disconnect);
 158                         #endif
 159
 160                 /* Tasks: */
 161                         /** This is the main USB management task. The USB driver requires that this task be executed
 162                          *  continuously when the USB system is active (device attached in host mode, or attached to a host
 163                          *  in device mode) in order to manage USB communications. This task may be executed inside an RTOS,
 164                          *  scheduler (e.g. the simple LUFA Scheduler), fast timer ISR or the main user application loop.
 165                          *
 166                          *  The USB task must be serviced within 50mS in all modes, when needed. The task may be serviced
 167                          *  at all times, or (for minimum CPU consumption):
 168                          *
 169                          *    - In device mode, it may be disabled at start-up, enabled on the firing of the USB_Connect event
 170                          *    and disabled again on the firing of the USB_Disconnect event.
 171                          *
 172                          *    - In host mode, it may be disabled at start-up, enabled on the firing of the USB_DeviceAttached
 173                          *    event and disabled again on the firing of the USB_DeviceUnattached event.
 174                          *
 175                          *  \see Events.h for more information on the USB events.
 176                          */
 177                         TASK(USB_USBTask);
 178
 179         /* Private Interface - For use in library only: */
 180         #if !defined(__DOXYGEN__)
 181                 /* Function Prototypes: */
 182                         #if defined(INCLUDE_FROM_USBTASK_C)
 183                                 #if defined(USB_CAN_BE_HOST)
 184                                         static void USB_HostTask(void);
 185                                 #endif
 186
 187                                 #if defined(USB_CAN_BE_DEVICE)
 188                                         static void USB_DeviceTask(void);
 189                                 #endif
 190                         #endif
 191
 192                 /* Macros: */
 193                         #define HOST_TASK_NONBLOCK_WAIT(duration, nextstate) {USB_HostState = HOST_STATE_WaitForDevice; WaitMSRemaining = duration; PostWaitState = nextstate; }
 194         #endif
 195
 196         /* Disable C linkage for C++ Compilers: */
 197                 #if defined(__cplusplus)
 198                         }
 199                 #endif
 200
 201 #endif