LUFA/Drivers/USB/Class/Device/CDC.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  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 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_USBClassCDC
  32  *  @defgroup Group_USBClassCDCDevice CDC Class Device Mode Driver
  33  *
  34  *  \section Sec_Dependencies Module Source Dependencies
  35  *  The following files must be built with any user project that uses this module:
  36  *    - LUFA/Drivers/USB/Class/Device/CDC.c
  37  *
  38  *  \section Module Description
  39  *  Device Mode USB Class driver framework interface, for the CDC USB Class driver.
  40  *
  41  *  \note There are several major drawbacks to the CDC-ACM standard USB class, however
  42  *        it is very standardized and thus usually available as a built-in driver on
  43  *        most platforms, and so is a better choice than a proprietary serial class.
  44  *
  45  *        One major issue with CDC-ACM is that it requires two Interface descriptors,
  46  *        which will upset most hosts when part of a multi-function "Composite" USB
  47  *        device, as each interface will be loaded into a separate driver instance. To
  48  *        conbat this, you should use the "Interface Association Descriptor" addendum to
  49  *        the USB standard which is available on most OSes when creating Composite devices.
  50  *
  51  *        Another major oversight is that there is no mechanism for the host to notify the
  52  *        device that there is a data sink on the host side ready to accept data. This
  53  *        means that the device may try to send data while the host isn't listening, causing
  54  *        lengthy blocking timeouts in the transmission routines. To combat this, it is
  55  *        recommended that the virtual serial line DTR (Data Terminal Ready) be used where
  56  *        possible to determine if a host application is ready for data.
  57  *
  58  *  @{
  59  */
  60
  61 #ifndef _CDC_CLASS_DEVICE_H_
  62 #define _CDC_CLASS_DEVICE_H_
  63
  64         /* Includes: */
  65                 #include "../../USB.h"
  66                 #include "../Common/CDC.h"
  67
  68                 #include <stdio.h>
  69                 #include <string.h>
  70
  71         /* Enable C linkage for C++ Compilers: */
  72                 #if defined(__cplusplus)
  73                         extern "C" {
  74                 #endif
  75
  76         /* Public Interface - May be used in end-application: */
  77                 /* Type Defines: */
  78                         /** Class state structure. An instance of this structure should be made for each CDC interface
  79                          *  within the user application, and passed to each of the CDC class driver functions as the
  80                          *  CDCInterfaceInfo parameter. This stores each CDC interface's configuration and state information.
  81                          */
  82                         typedef struct
  83                         {
  84                                 const struct
  85                                 {
  86                                         uint8_t  ControlInterfaceNumber; /**< Interface number of the CDC control interface within the device */
  87
  88                                         uint8_t  DataINEndpointNumber; /**< Endpoint number of the CDC interface's IN data endpoint */
  89                                         uint16_t DataINEndpointSize; /**< Size in bytes of the CDC interface's IN data endpoint */
  90                                         bool     DataINEndpointDoubleBank; /** Indicates if the CDC interface's IN data endpoint should use double banking */
  91
  92                                         uint8_t  DataOUTEndpointNumber; /**< Endpoint number of the CDC interface's OUT data endpoint */
  93                                         uint16_t DataOUTEndpointSize;  /**< Size in bytes of the CDC interface's OUT data endpoint */
  94                                         bool     DataOUTEndpointDoubleBank; /** Indicates if the CDC interface's OUT data endpoint should use double banking */
  95
  96                                         uint8_t  NotificationEndpointNumber; /**< Endpoint number of the CDC interface's IN notification endpoint, if used */
  97                                         uint16_t NotificationEndpointSize;  /**< Size in bytes of the CDC interface's IN notification endpoint, if used */
  98                                         bool     NotificationEndpointDoubleBank; /** Indicates if the CDC interface's notification endpoint should use double banking */
  99                                 } Config; /**< Config data for the USB class interface within the device. All elements in this section
 100                                            *   <b>must</b> be set or the interface will fail to enumerate and operate correctly.
 101                                            */
 102                                 struct
 103                                 {
 104                                         struct
 105                                         {
 106                                                 uint8_t HostToDevice; /**< Control line states from the host to device, as a set of CDC_CONTROL_LINE_OUT_*
 107                                                                                            *   masks. This value is updated each time \ref CDC_Device_USBTask() is called.
 108                                                                                            */
 109                                                 uint8_t DeviceToHost; /**< Control line states from the device to host, as a set of CDC_CONTROL_LINE_IN_*
 110                                                                                            *   masks - to notify the host of changes to these values, call the
 111                                                                                            *   \ref CDC_Device_SendControlLineStateChange() function.
 112                                                                                            */
 113                                         } ControlLineStates; /**< Current states of the virtual serial port's control lines between the device and host. */
 114
 115                                         struct
 116                                         {
 117                                                 uint32_t BaudRateBPS; /**< Baud rate of the virtual serial port, in bits per second */
 118                                                 uint8_t  CharFormat; /**< Character format of the virtual serial port, a value from the
 119                                                                                           *   CDCDevice_CDC_LineCodingFormats_t enum
 120                                                                                           */
 121                                                 uint8_t  ParityType; /**< Parity setting of the virtual serial port, a value from the
 122                                                                                           *   CDCDevice_LineCodingParity_t enum
 123                                                                                           */
 124                                                 uint8_t  DataBits; /**< Bits of data per character of the virtual serial port */
 125                                         } LineEncoding; /** Line encoding used in the virtual serial port, for the device's information. This is generally
 126                                                          *  only used if the virtual serial port data is to be reconstructed on a physical UART.
 127                                                          */
 128                                 } State; /**< State data for the USB class interface within the device. All elements in this section
 129                                           *   are reset to their defaults when the interface is enumerated.
 130                                           */
 131                         } USB_ClassInfo_CDC_Device_t;
 132
 133                 /* Function Prototypes: */
 134                         /** Configures the endpoints of a given CDC interface, ready for use. This should be linked to the library
 135                          *  \ref EVENT_USB_Device_ConfigurationChanged() event so that the endpoints are configured when the configuration containing
 136                          *  the given CDC interface is selected.
 137                          *
 138                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 139                          *
 140                          *  \return Boolean true if the endpoints were successfully configured, false otherwise
 141                          */
 142                         bool CDC_Device_ConfigureEndpoints(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 143
 144                         /** Processes incoming control requests from the host, that are directed to the given CDC class interface. This should be
 145                          *  linked to the library \ref EVENT_USB_Device_UnhandledControlRequest() event.
 146                          *
 147                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 148                          */
 149                         void CDC_Device_ProcessControlRequest(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 150
 151                         /** General management task for a given CDC class interface, required for the correct operation of the interface. This should
 152                          *  be called frequently in the main program loop, before the master USB management task \ref USB_USBTask().
 153                          *
 154                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 155                          */
 156                         void CDC_Device_USBTask(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 157
 158                         /** CDC class driver event for a line encoding change on a CDC interface. This event fires each time the host requests a
 159                          *  line encoding change (containing the serial parity, baud and other configuration information) and may be hooked in the
 160                          *  user program by declaring a handler function with the same name and parameters listed here. The new line encoding
 161                          *  settings are available in the LineEncoding structure inside the CDC interface structure passed as a parameter.
 162                          *
 163                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 164                          */
 165                         void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 166
 167                         /** CDC class driver event for a control line state change on a CDC interface. This event fires each time the host requests a
 168                          *  control line state change (containing the virtual serial control line states, such as DTR) and may be hooked in the
 169                          *  user program by declaring a handler function with the same name and parameters listed here. The new control line states
 170                          *  are available in the ControlLineStates.HostToDevice value inside the CDC interface structure passed as a parameter, set as
 171                          *  a mask of CDC_CONTROL_LINE_OUT_* masks.
 172                          *
 173                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 174                          */
 175                         void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 176
 177                         /** Sends a given string to the attached USB host, if connected. If a host is not connected when the function is called, the
 178                          *  string is discarded. Bytes will be queued for transmission to the host until either the endpoint bank becomes full, or the
 179                          *  \ref CDC_Device_Flush() function is called to flush the pending data to the host. This allows for multiple bytes to be
 180                          *  packed into a single endpoint packet, increasing data throughput.
 181                          *
 182                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 183                          *        the call will fail.
 184                          *
 185                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 186                          *  \param[in] Data  Pointer to the string to send to the host
 187                          *  \param[in] Length  Size in bytes of the string to send to the host
 188                          *
 189                          *  \return A value from the \ref Endpoint_Stream_RW_ErrorCodes_t enum
 190                          */
 191                         uint8_t CDC_Device_SendString(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo, char* const Data, const uint16_t Length)
 192                                                       ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 193
 194                         /** Sends a given byte to the attached USB host, if connected. If a host is not connected when the function is called, the
 195                          *  byte is discarded. Bytes will be queued for transmission to the host until either the endpoint bank becomes full, or the
 196                          *  \ref CDC_Device_Flush() function is called to flush the pending data to the host. This allows for multiple bytes to be
 197                          *  packed into a single endpoint packet, increasing data throughput.
 198                          *
 199                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 200                          *        the call will fail.
 201                          *
 202                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 203                          *  \param[in] Data  Byte of data to send to the host
 204                          *
 205                          *  \return A value from the \ref Endpoint_WaitUntilReady_ErrorCodes_t enum
 206                          */
 207                         uint8_t CDC_Device_SendByte(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo, const uint8_t Data) ATTR_NON_NULL_PTR_ARG(1);
 208
 209                         /** Determines the number of bytes received by the CDC interface from the host, waiting to be read.
 210                          *
 211                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 212                          *        the call will fail.
 213                          *
 214                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 215                          *
 216                          *  \return Total number of buffered bytes received from the host
 217                          */
 218                         uint16_t CDC_Device_BytesReceived(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 219
 220                         /** Reads a byte of data from the host. If no data is waiting to be read of if a USB host is not connected, the function
 221                          *  returns 0. The \ref CDC_Device_BytesReceived() function should be queried before data is received to ensure that no data
 222                          *  underflow occurs.
 223                          *
 224                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 225                          *        the call will fail.
 226                          *
 227                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 228                          *
 229                          *  \return Next received byte from the host, or 0 if no data received
 230                          */
 231                         uint8_t CDC_Device_ReceiveByte(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 232
 233                         /** Flushes any data waiting to be sent, ensuring that the send buffer is cleared.
 234                          *
 235                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 236                          *        the call will fail.
 237                          *
 238                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 239                          *
 240                          *  \return A value from the \ref Endpoint_WaitUntilReady_ErrorCodes_t enum
 241                          */
 242                         uint8_t CDC_Device_Flush(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 243
 244                         /** Sends a Serial Control Line State Change notification to the host. This should be called when the virtual serial
 245                          *  control lines (DCD, DSR, etc.) have changed states, or to give BREAK notifications to the host. Line states persist
 246                          *  until they are cleared via a second notification. This should be called each time the CDC class driver's
 247                          *  ControlLineStates.DeviceToHost value is updated to push the new states to the USB host.
 248                          *
 249                          *  \note This function must only be called when the Device state machine is in the DEVICE_STATE_Configured state or
 250                          *        the call will fail.
 251                          *
 252                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 253                          */
 254                         void CDC_Device_SendControlLineStateChange(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo) ATTR_NON_NULL_PTR_ARG(1);
 255
 256                         /** Creates a standard characer stream for the given CDC Device instance so that it can be used with all the regular
 257                          *  functions in the avr-libc <stdio.h> library that accept a FILE stream as a destination (e.g. fprintf). The created
 258                          *  stream is bidirectional and can be used for both input and output functions.
 259                          *
 260                          *  Reading data from this stream is non-blocking, i.e. in most instances, complete strings cannot be read in by a single
 261                          *  fetch, as the endpoint will not be ready at some point in the transmission, aborting the transfer. However, this may
 262                          *  be used when the read data is processed byte-per-bye (via getc()) or when the user application will implement its own
 263                          *  line buffering.
 264                          *
 265                          *  \note The created stream can be given as stdout if desired to direct the standard output from all <stdio.h> functions
 266                          *        to the given CDC interface.
 267                          *
 268                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 269                          *  \param[in,out] Stream  Pointer to a FILE structure where the created stream should be placed
 270                          */
 271                         void CDC_Device_CreateStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE* Stream);
 272
 273                         /** Identical to CDC_Device_CreateStream(), except that reads are blocking until the calling stream function terminates
 274                          *  the transfer. While blocking, the USB and CDC service tasks are called repeatedly to maintain USB communications.
 275                          *
 276                          *  \param[in,out] CDCInterfaceInfo  Pointer to a structure containing a CDC Class configuration and state
 277                          *  \param[in,out] Stream  Pointer to a FILE structure where the created stream should be placed
 278                          */
 279                         void CDC_Device_CreateBlockingStream(USB_ClassInfo_CDC_Device_t* CDCInterfaceInfo, FILE* Stream);
 280
 281         /* Private Interface - For use in library only: */
 282         #if !defined(__DOXYGEN__)
 283                 /* Function Prototypes: */
 284                         #if defined(INCLUDE_FROM_CDC_CLASS_DEVICE_C)
 285                                 static int CDC_Device_putchar(char c, FILE* Stream);
 286                                 static int CDC_Device_getchar(FILE* Stream);
 287                                 static int CDC_Device_getchar_Blocking(FILE* Stream);
 288
 289                                 void CDC_Device_Event_Stub(void);
 290                                 void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)
 291                                                                                                                   ATTR_WEAK ATTR_NON_NULL_PTR_ARG(1) ATTR_ALIAS(CDC_Device_Event_Stub);
 292                                 void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)
 293                                                                                                                          ATTR_WEAK ATTR_NON_NULL_PTR_ARG(1) ATTR_ALIAS(CDC_Device_Event_Stub);
 294                         #endif
 295
 296         #endif
 297
 298         /* Disable C linkage for C++ Compilers: */
 299                 #if defined(__cplusplus)
 300                         }
 301                 #endif
 302
 303 #endif
 304
 305 /** @} */