protocol/usb_hid/arduino-1.0.1/cores/arduino/CDC.cpp

   1
   2
   3 /* Copyright (c) 2011, Peter Barrett
   4 **
   5 ** Permission to use, copy, modify, and/or distribute this software for
   6 ** any purpose with or without fee is hereby granted, provided that the
   7 ** above copyright notice and this permission notice appear in all copies.
   8 **
   9 ** THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  10 ** WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  11 ** WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
  12 ** BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
  13 ** OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  14 ** WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  15 ** ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  16 ** SOFTWARE.
  17 */
  18
  19 #include "Platform.h"
  20 #include "USBAPI.h"
  21 #include <avr/wdt.h>
  22
  23 #if defined(USBCON)
  24 #ifdef CDC_ENABLED
  25
  26 #if (RAMEND < 1000)
  27 #define SERIAL_BUFFER_SIZE 16
  28 #else
  29 #define SERIAL_BUFFER_SIZE 64
  30 #endif
  31
  32 struct ring_buffer
  33 {
  34         unsigned char buffer[SERIAL_BUFFER_SIZE];
  35         volatile int head;
  36         volatile int tail;
  37 };
  38
  39 ring_buffer cdc_rx_buffer = { { 0 }, 0, 0};
  40
  41 typedef struct
  42 {
  43         u32     dwDTERate;
  44         u8      bCharFormat;
  45         u8      bParityType;
  46         u8      bDataBits;
  47         u8      lineState;
  48 } LineInfo;
  49
  50 static volatile LineInfo _usbLineInfo = { 57600, 0x00, 0x00, 0x00, 0x00 };
  51
  52 #define WEAK __attribute__ ((weak))
  53
  54 extern const CDCDescriptor _cdcInterface PROGMEM;
  55 const CDCDescriptor _cdcInterface =
  56 {
  57         D_IAD(0,2,CDC_COMMUNICATION_INTERFACE_CLASS,CDC_ABSTRACT_CONTROL_MODEL,1),
  58
  59         //      CDC communication interface
  60         D_INTERFACE(CDC_ACM_INTERFACE,1,CDC_COMMUNICATION_INTERFACE_CLASS,CDC_ABSTRACT_CONTROL_MODEL,0),
  61         D_CDCCS(CDC_HEADER,0x10,0x01),                                                          // Header (1.10 bcd)
  62         D_CDCCS(CDC_CALL_MANAGEMENT,1,1),                                                       // Device handles call management (not)
  63         D_CDCCS4(CDC_ABSTRACT_CONTROL_MANAGEMENT,6),                            // SET_LINE_CODING, GET_LINE_CODING, SET_CONTROL_LINE_STATE supported
  64         D_CDCCS(CDC_UNION,CDC_ACM_INTERFACE,CDC_DATA_INTERFACE),        // Communication interface is master, data interface is slave 0
  65         D_ENDPOINT(USB_ENDPOINT_IN (CDC_ENDPOINT_ACM),USB_ENDPOINT_TYPE_INTERRUPT,0x10,0x40),
  66
  67         //      CDC data interface
  68         D_INTERFACE(CDC_DATA_INTERFACE,2,CDC_DATA_INTERFACE_CLASS,0,0),
  69         D_ENDPOINT(USB_ENDPOINT_OUT(CDC_ENDPOINT_OUT),USB_ENDPOINT_TYPE_BULK,0x40,0),
  70         D_ENDPOINT(USB_ENDPOINT_IN (CDC_ENDPOINT_IN ),USB_ENDPOINT_TYPE_BULK,0x40,0)
  71 };
  72
  73 int WEAK CDC_GetInterface(u8* interfaceNum)
  74 {
  75         interfaceNum[0] += 2;   // uses 2
  76         return USB_SendControl(TRANSFER_PGM,&_cdcInterface,sizeof(_cdcInterface));
  77 }
  78
  79 bool WEAK CDC_Setup(Setup& setup)
  80 {
  81         u8 r = setup.bRequest;
  82         u8 requestType = setup.bmRequestType;
  83
  84         if (REQUEST_DEVICETOHOST_CLASS_INTERFACE == requestType)
  85         {
  86                 if (CDC_GET_LINE_CODING == r)
  87                 {
  88                         USB_SendControl(0,(void*)&_usbLineInfo,7);
  89                         return true;
  90                 }
  91         }
  92
  93         if (REQUEST_HOSTTODEVICE_CLASS_INTERFACE == requestType)
  94         {
  95                 if (CDC_SET_LINE_CODING == r)
  96                 {
  97                         USB_RecvControl((void*)&_usbLineInfo,7);
  98                         return true;
  99                 }
 100
 101                 if (CDC_SET_CONTROL_LINE_STATE == r)
 102                 {
 103                         _usbLineInfo.lineState = setup.wValueL;
 104
 105                         // auto-reset into the bootloader is triggered when the port, already
 106                         // open at 1200 bps, is closed.  this is the signal to start the watchdog
 107                         // with a relatively long period so it can finish housekeeping tasks
 108                         // like servicing endpoints before the sketch ends
 109                         if (1200 == _usbLineInfo.dwDTERate) {
 110                                 // We check DTR state to determine if host port is open (bit 0 of lineState).
 111                                 if ((_usbLineInfo.lineState & 0x01) == 0) {
 112                                         *(uint16_t *)0x0800 = 0x7777;
 113                                         wdt_enable(WDTO_120MS);
 114                                 } else {
 115                                         // Most OSs do some intermediate steps when configuring ports and DTR can
 116                                         // twiggle more than once before stabilizing.
 117                                         // To avoid spurious resets we set the watchdog to 250ms and eventually
 118                                         // cancel if DTR goes back high.
 119
 120                                         wdt_disable();
 121                                         wdt_reset();
 122                                         *(uint16_t *)0x0800 = 0x0;
 123                                 }
 124                         }
 125                         return true;
 126                 }
 127         }
 128         return false;
 129 }
 130
 131
 132 int _serialPeek = -1;
 133 void Serial_::begin(uint16_t baud_count)
 134 {
 135 }
 136
 137 void Serial_::end(void)
 138 {
 139 }
 140
 141 void Serial_::accept(void)
 142 {
 143         ring_buffer *buffer = &cdc_rx_buffer;
 144         int c = USB_Recv(CDC_RX);
 145         int i = (unsigned int)(buffer->head+1) % SERIAL_BUFFER_SIZE;
 146
 147         // if we should be storing the received character into the location
 148         // just before the tail (meaning that the head would advance to the
 149         // current location of the tail), we're about to overflow the buffer
 150         // and so we don't write the character or advance the head.
 151         if (i != buffer->tail) {
 152                 buffer->buffer[buffer->head] = c;
 153                 buffer->head = i;
 154         }
 155 }
 156
 157 int Serial_::available(void)
 158 {
 159         ring_buffer *buffer = &cdc_rx_buffer;
 160         return (unsigned int)(SERIAL_BUFFER_SIZE + buffer->head - buffer->tail) % SERIAL_BUFFER_SIZE;
 161 }
 162
 163 int Serial_::peek(void)
 164 {
 165         ring_buffer *buffer = &cdc_rx_buffer;
 166         if (buffer->head == buffer->tail) {
 167                 return -1;
 168         } else {
 169                 return buffer->buffer[buffer->tail];
 170         }
 171 }
 172
 173 int Serial_::read(void)
 174 {
 175         ring_buffer *buffer = &cdc_rx_buffer;
 176         // if the head isn't ahead of the tail, we don't have any characters
 177         if (buffer->head == buffer->tail) {
 178                 return -1;
 179         } else {
 180                 unsigned char c = buffer->buffer[buffer->tail];
 181                 buffer->tail = (unsigned int)(buffer->tail + 1) % SERIAL_BUFFER_SIZE;
 182                 return c;
 183         }
 184 }
 185
 186 void Serial_::flush(void)
 187 {
 188         USB_Flush(CDC_TX);
 189 }
 190
 191 size_t Serial_::write(uint8_t c)
 192 {
 193         /* only try to send bytes if the high-level CDC connection itself
 194          is open (not just the pipe) - the OS should set lineState when the port
 195          is opened and clear lineState when the port is closed.
 196          bytes sent before the user opens the connection or after
 197          the connection is closed are lost - just like with a UART. */
 198
 199         // TODO - ZE - check behavior on different OSes and test what happens if an
 200         // open connection isn't broken cleanly (cable is yanked out, host dies
 201         // or locks up, or host virtual serial port hangs)
 202         if (_usbLineInfo.lineState > 0) {
 203                 int r = USB_Send(CDC_TX,&c,1);
 204                 if (r > 0) {
 205                         return r;
 206                 } else {
 207                         setWriteError();
 208                         return 0;
 209                 }
 210         }
 211         setWriteError();
 212         return 0;
 213 }
 214
 215 // This operator is a convenient way for a sketch to check whether the
 216 // port has actually been configured and opened by the host (as opposed
 217 // to just being connected to the host).  It can be used, for example, in
 218 // setup() before printing to ensure that an application on the host is
 219 // actually ready to receive and display the data.
 220 // We add a short delay before returning to fix a bug observed by Federico
 221 // where the port is configured (lineState != 0) but not quite opened.
 222 Serial_::operator bool() {
 223         bool result = false;
 224         if (_usbLineInfo.lineState > 0)
 225                 result = true;
 226         delay(10);
 227         return result;
 228 }
 229
 230 Serial_ Serial;
 231
 232 #endif
 233 #endif /* if defined(USBCON) */