LUFA/Drivers/USB/Core/USBTask.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2015.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2015  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all 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 disclaims 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  *  \brief Main USB service task management.
  33  *
  34  *  This file contains the function definitions required for the main USB service task, which must be called
  35  *  from the user application to ensure that the USB connection to or from a connected USB device is maintained.
  36  *
  37  *  \note This file should not be included directly. It is automatically included as needed by the USB driver
  38  *        dispatch header located in LUFA/Drivers/USB/USB.h.
  39  */
  40
  41 #ifndef __USBTASK_H__
  42 #define __USBTASK_H__
  43
  44         /* Includes: */
  45                 #include "../../../Common/Common.h"
  46                 #include "USBMode.h"
  47                 #include "USBController.h"
  48                 #include "Events.h"
  49                 #include "StdRequestType.h"
  50                 #include "StdDescriptors.h"
  51
  52                 #if defined(USB_CAN_BE_DEVICE)
  53                         #include "DeviceStandardReq.h"
  54                 #endif
  55
  56                 #if defined(USB_CAN_BE_HOST)
  57                         #include "HostStandardReq.h"
  58                 #endif
  59
  60         /* Enable C linkage for C++ Compilers: */
  61                 #if defined(__cplusplus)
  62                         extern "C" {
  63                 #endif
  64
  65         /* Preprocessor Checks: */
  66                 #if !defined(__INCLUDE_FROM_USB_DRIVER)
  67                         #error Do not include this file directly. Include LUFA/Drivers/USB/USB.h instead.
  68                 #endif
  69
  70         /* Public Interface - May be used in end-application: */
  71                 /* Global Variables: */
  72                         /** Indicates if the USB interface is currently initialized but not necessarily connected to a host
  73                          *  or device (i.e. if \ref USB_Init() has been run). If this is false, all other library globals related
  74                          *  to the USB driver are invalid.
  75                          *
  76                          *  \attention This variable should be treated as read-only in the user application, and never manually
  77                          *             changed in value.
  78                          *
  79                          *  \ingroup Group_USBManagement
  80                          */
  81                         extern volatile bool USB_IsInitialized;
  82
  83                         /** Structure containing the last received Control request when in Device mode (for use in user-applications
  84                          *  inside of the \ref EVENT_USB_Device_ControlRequest() event, or for filling up with a control request to
  85                          *  issue when in Host mode before calling \ref USB_Host_SendControlRequest().
  86                          *
  87                          *  \note The contents of this structure is automatically endian-corrected for the current CPU architecture.
  88                          *
  89                          *  \ingroup Group_USBManagement
  90                          */
  91                          extern USB_Request_Header_t USB_ControlRequest;
  92
  93                         #if defined(USB_CAN_BE_HOST) || defined(__DOXYGEN__)
  94                                 #if !defined(HOST_STATE_AS_GPIOR) || defined(__DOXYGEN__)
  95                                         /** Indicates the current host state machine state. When in host mode, this indicates the state
  96                                          *  via one of the values of the \ref USB_Host_States_t enum values.
  97                                          *
  98                                          *  This value should not be altered by the user application as it is handled automatically by the
  99                                          *  library.
 100                                          *
 101                                          *  To reduce program size and speed up checks of this global on the AVR8 architecture, it can be
 102                                          *  placed into one of the AVR's \c GPIOR hardware registers instead of RAM by defining the
 103                                          *  \c HOST_STATE_AS_GPIOR token to a value between 0 and 2 in the project makefile and passing it to
 104                                          *  the compiler via the -D switch. When defined, the corresponding GPIOR register should not be used
 105                                          *  in the user application except implicitly via the library APIs.
 106                                          *
 107                                          *  \note This global is only present if the user application can be a USB host.
 108                                          *
 109                                          *  \see \ref USB_Host_States_t for a list of possible device states.
 110                                          *
 111                                          *  \ingroup Group_Host
 112                                          */
 113                                         extern volatile uint8_t USB_HostState;
 114                                 #else
 115                                         #define USB_HostState            CONCAT_EXPANDED(GPIOR, HOST_STATE_AS_GPIOR)
 116                                 #endif
 117                         #endif
 118
 119                         #if defined(USB_CAN_BE_DEVICE) || defined(__DOXYGEN__)
 120                                 #if !defined(DEVICE_STATE_AS_GPIOR) || defined(__DOXYGEN__)
 121                                         /** Indicates the current device state machine state. When in device mode, this indicates the state
 122                                          *  via one of the values of the \ref USB_Device_States_t enum values.
 123                                          *
 124                                          *  This value should not be altered by the user application as it is handled automatically by the
 125                                          *  library. The only exception to this rule is if the NO_LIMITED_CONTROLLER_CONNECT token is used
 126                                          *  (see \ref EVENT_USB_Device_Connect() and \ref EVENT_USB_Device_Disconnect() events).
 127                                          *
 128                                          *  To reduce program size and speed up checks of this global on the AVR8 architecture, it can be
 129                                          *  placed into one of the AVR's \c GPIOR hardware registers instead of RAM by defining the
 130                                          *  \c DEVICE_STATE_AS_GPIOR token to a value between 0 and 2 in the project makefile and passing it to
 131                                          *  the compiler via the -D switch. When defined, the corresponding GPIOR register should not be used
 132                                          *  in the user application except implicitly via the library APIs.
 133                                          *
 134                                          *  \attention This variable should be treated as read-only in the user application, and never manually
 135                                          *             changed in value except in the circumstances outlined above.
 136                                          *
 137                                          *  \note This global is only present if the user application can be a USB device.
 138                                          *        \n\n
 139                                          *
 140                                          *  \see \ref USB_Device_States_t for a list of possible device states.
 141                                          *
 142                                          *  \ingroup Group_Device
 143                                          */
 144                                         extern volatile uint8_t USB_DeviceState;
 145                                 #else
 146                                         #define USB_DeviceState            CONCAT_EXPANDED(GPIOR, DEVICE_STATE_AS_GPIOR)
 147                                 #endif
 148                         #endif
 149
 150                 /* Function Prototypes: */
 151                         /** This is the main USB management task. The USB driver requires this task to be executed
 152                          *  continuously when the USB system is active (device attached in host mode, or attached to a host
 153                          *  in device mode) in order to manage USB communications. This task may be executed inside an RTOS,
 154                          *  fast timer ISR or the main user application loop.
 155                          *
 156                          *  The USB task must be serviced within 30ms while in device mode, or within 1ms while in host mode.
 157                          *  The task may be serviced at all times, or (for minimum CPU consumption):
 158                          *
 159                          *    - In device mode, it may be disabled at start-up, enabled on the firing of the \ref EVENT_USB_Device_Connect()
 160                          *      event and disabled again on the firing of the \ref EVENT_USB_Device_Disconnect() event.
 161                          *
 162                          *    - In host mode, it may be disabled at start-up, enabled on the firing of the \ref EVENT_USB_Host_DeviceAttached()
 163                          *      event and disabled again on the firing of the \ref EVENT_USB_Host_DeviceEnumerationComplete() or
 164                          *      \ref EVENT_USB_Host_DeviceEnumerationFailed() events.
 165                          *
 166                          *  If in device mode (only), the control endpoint can instead be managed via interrupts entirely by the library
 167                          *  by defining the INTERRUPT_CONTROL_ENDPOINT token and passing it to the compiler via the -D switch.
 168                          *
 169                          *  \see \ref Group_Events for more information on the USB events.
 170                          *
 171                          *  \ingroup Group_USBManagement
 172                          */
 173                         void USB_USBTask(void);
 174
 175         /* Private Interface - For use in library only: */
 176         #if !defined(__DOXYGEN__)
 177                 /* Function Prototypes: */
 178                         #if defined(__INCLUDE_FROM_USBTASK_C)
 179                                 #if defined(USB_CAN_BE_HOST)
 180                                         static void USB_HostTask(void);
 181                                 #endif
 182
 183                                 #if defined(USB_CAN_BE_DEVICE)
 184                                         static void USB_DeviceTask(void);
 185                                 #endif
 186                         #endif
 187
 188                 /* Macros: */
 189                         #define HOST_TASK_NONBLOCK_WAIT(Duration, NextState) do { USB_HostState   = HOST_STATE_WaitForDevice; \
 190                                                                                   WaitMSRemaining = (Duration);               \
 191                                                                                   PostWaitState   = (NextState);              } while (0)
 192         #endif
 193
 194         /* Disable C linkage for C++ Compilers: */
 195                 #if defined(__cplusplus)
 196                         }
 197                 #endif
 198
 199 #endif
 200