StreamCallbacks.h 3.74 KB
 Dean Camera committed Feb 23, 2009 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 /* LUFA Library Copyright (C) Dean Camera, 2009. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. The author disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software. */  Dean Camera committed Apr 16, 2009 31 32 33 /** \ingroup Group_USB * @defgroup Group_StreamCallbacks Endpoint and Pipe Stream Callbacks *  Dean Camera committed Apr 19, 2009 34 35  * Macros and enums for the stream callback routines. This module contains the code required to easily set up * stream callback functions which can be used to force early abort of a stream read/write process.  Dean Camera committed Apr 16, 2009 36 37 38 39  * * @{ */  Dean Camera committed Feb 23, 2009 40 41 42 43 44 45 46 47 48 49 #ifndef __STREAMCALLBACK_H__ #define __STREAMCALLBACK_H__ /* Public Interface - May be used in end-application: */ /* Macros: */ /** Creates a prototype for or begins a stream callback routine. Stream callback routines are small * routines which are executed during stream read or writes (if the callback-enabled versions of * these functions are used) which allow the user application to abort the transfer when certain * arbitrary conditions are met. *  Dean Camera committed Apr 22, 2009 50  * Stream callback functions should return a value from the \ref StreamCallback_Return_ErrorCodes_t  Dean Camera committed Feb 23, 2009 51 52  * enum. *  Dean Camera committed Mar 31, 2009 53  * Usage Example (Device Endpoint, but applicable for Host Pipes also):  Dean Camera committed Feb 23, 2009 54 55 56 57 58 59 60 61 62 63 64 65 66  * \code * STREAM_CALLBACK(GlobalNotSet); // Callback Prototype * * STREAM_CALLBACK(GlobalNotSet) * { * if (MyGlobal == false) * return ENDPOINT_STREAMCALLBACK_Continue; * else * return ENDPOINT_STREAMCALLBACK_Abort; * } * * //... * // Inside some routine:  Dean Camera committed Mar 29, 2009 67 68  * if (Endpoint_Write_Stream_LE(DataBuffer, sizeof(DataBuffer), GlobalNotSet) == * ENDPOINT_RWSTREAM_ERROR_CallbackAborted)  Dean Camera committed Feb 23, 2009 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85  * { * // Do something when the callback aborted the transfer early * } * \endcode */ #define STREAM_CALLBACK(name) uint8_t name (void) /** Used with the Endpoint and Pipe stream functions as the callback function parameter, indicating that the stream * call has no callback function to be called between USB packets. */ #define NO_STREAM_CALLBACK NULL /* Enums: */ /** Enum for the possible error return codes of a stream callback function */ enum StreamCallback_Return_ErrorCodes_t { STREAMCALLBACK_Continue = 0, /**< Continue sending or receiving the stream. */  Dean Camera committed Mar 29, 2009 86  STREAMCALLBACK_Abort = 1, /**< Abort the stream send or receiving process. */  Dean Camera committed Feb 23, 2009 87  };  Dean Camera committed May 15, 2009 88 89 90 91 92 93 94 95 96  /* Type Defines: */ /** Type define for a Stream Callback function (function taking no arguments and retuning a * uint8_t value). * * \see \ref STREAM_CALLBACK macro for more details */ typedef uint8_t (* const StreamCallbackPtr_t)(void);  Dean Camera committed Feb 23, 2009 97 #endif  Dean Camera committed Apr 16, 2009 98 99  /** @} */