git.zerfleddert.de Git - proxmark3-svn/blob - common/usb_cdc.c

   1 /*
   2  * at91sam7s USB CDC device implementation
   3  *
   4  * Copyright (c) 2012, Roel Verdult
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the copyright holders nor the
  15  * names of its contributors may be used to endorse or promote products
  16  * derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  27  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * based on the "Basic USB Example" from ATMEL (doc6123.pdf)
  30  *
  31  * @file usb_cdc.c
  32  * @brief
  33  */
  34
  35 #include "usb_cdc.h"
  36 #include "config_gpio.h"
  37
  38 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  39 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
  40 #define AT91C_EP_IN_SIZE  0x40
  41 #define AT91C_EP_OUT         1
  42 #define AT91C_EP_OUT_SIZE 0x40
  43 #define AT91C_EP_IN          2
  44
  45 const char devDescriptor[] = {
  46         /* Device descriptor */
  47         0x12,      // bLength
  48         0x01,      // bDescriptorType
  49         0x10,0x01, // Complies with USB Spec. Release (0110h = release 1.10)
  50         0x02,      // bDeviceClass:    CDC class code
  51         0x00,      // bDeviceSubclass: CDC class sub code
  52         0x00,      // bDeviceProtocol: CDC Device protocol
  53         0x08,      // bMaxPacketSize0
  54         0x2d,0x2d, // Vendor ID (--)
  55         0x4d,0x50, // Product ID (PM), transmitted in reverse
  56         0x01,0x00, // Device release number (0001)
  57         0x01,      // iManufacturer    // 0x01
  58         0x00,      // iProduct
  59         0x00,      // SerialNumber
  60         0x01       // bNumConfigs
  61 };
  62
  63 const char cfgDescriptor[] = {
  64         /* ============== CONFIGURATION 1 =========== */
  65         /* Configuration 1 descriptor */
  66         0x09,   // CbLength
  67         0x02,   // CbDescriptorType
  68         0x43,   // CwTotalLength 2 EP + Control
  69         0x00,
  70         0x02,   // CbNumInterfaces
  71         0x01,   // CbConfigurationValue
  72         0x00,   // CiConfiguration
  73         0xC0,   // CbmAttributes 0xA0
  74         0x00,   // CMaxPower
  75
  76         /* Communication Class Interface Descriptor Requirement */
  77         0x09, // bLength
  78         0x04, // bDescriptorType
  79         0x00, // bInterfaceNumber
  80         0x00, // bAlternateSetting
  81         0x01, // bNumEndpoints
  82         0x02, // bInterfaceClass
  83         0x02, // bInterfaceSubclass
  84         0x00, // bInterfaceProtocol
  85         0x00, // iInterface
  86
  87         /* Header Functional Descriptor */
  88         0x05, // bFunction Length
  89         0x24, // bDescriptor type: CS_INTERFACE
  90         0x00, // bDescriptor subtype: Header Func Desc
  91         0x10, // bcdCDC:1.1
  92         0x01,
  93
  94         /* ACM Functional Descriptor */
  95         0x04, // bFunctionLength
  96         0x24, // bDescriptor Type: CS_INTERFACE
  97         0x02, // bDescriptor Subtype: ACM Func Desc
  98         0x00, // bmCapabilities
  99
 100         /* Union Functional Descriptor */
 101         0x05, // bFunctionLength
 102         0x24, // bDescriptorType: CS_INTERFACE
 103         0x06, // bDescriptor Subtype: Union Func Desc
 104         0x00, // bMasterInterface: Communication Class Interface
 105         0x01, // bSlaveInterface0: Data Class Interface
 106
 107         /* Call Management Functional Descriptor */
 108         0x05, // bFunctionLength
 109         0x24, // bDescriptor Type: CS_INTERFACE
 110         0x01, // bDescriptor Subtype: Call Management Func Desc
 111         0x00, // bmCapabilities: D1 + D0
 112         0x01, // bDataInterface: Data Class Interface 1
 113
 114         /* Endpoint 1 descriptor */
 115         0x07,   // bLength
 116         0x05,   // bDescriptorType
 117         0x83,   // bEndpointAddress, Endpoint 03 - IN
 118         0x03,   // bmAttributes      INT
 119         0x08,   // wMaxPacketSize
 120         0x00,
 121         0xFF,   // bInterval
 122
 123         /* Data Class Interface Descriptor Requirement */
 124         0x09, // bLength
 125         0x04, // bDescriptorType
 126         0x01, // bInterfaceNumber
 127         0x00, // bAlternateSetting
 128         0x02, // bNumEndpoints
 129         0x0A, // bInterfaceClass
 130         0x00, // bInterfaceSubclass
 131         0x00, // bInterfaceProtocol
 132         0x00, // iInterface
 133
 134         /* First alternate setting */
 135         /* Endpoint 1 descriptor */
 136         0x07,   // bLength
 137         0x05,   // bDescriptorType
 138         0x01,   // bEndpointAddress, Endpoint 01 - OUT
 139         0x02,   // bmAttributes      BULK
 140         AT91C_EP_OUT_SIZE,   // wMaxPacketSize
 141         0x00,
 142         0x00,   // bInterval
 143
 144         /* Endpoint 2 descriptor */
 145         0x07,   // bLength
 146         0x05,   // bDescriptorType
 147         0x82,   // bEndpointAddress, Endpoint 02 - IN
 148         0x02,   // bmAttributes      BULK
 149         AT91C_EP_IN_SIZE,   // wMaxPacketSize
 150         0x00,
 151         0x00    // bInterval
 152 };
 153
 154 const char strDescriptor[] = {
 155   26,                           // Length
 156   0x03,                 // Type is string
 157   'p', 0x00,
 158   'r', 0x00,
 159   'o', 0x00,
 160   'x', 0x00,
 161   'm', 0x00,
 162   'a', 0x00,
 163   'r', 0x00,
 164   'k', 0x00,
 165   '.', 0x00,
 166   'o', 0x00,
 167   'r', 0x00,
 168   'g', 0x00,
 169 };
 170
 171
 172 /* USB standard request code */
 173 #define STD_GET_STATUS_ZERO           0x0080
 174 #define STD_GET_STATUS_INTERFACE      0x0081
 175 #define STD_GET_STATUS_ENDPOINT       0x0082
 176
 177 #define STD_CLEAR_FEATURE_ZERO        0x0100
 178 #define STD_CLEAR_FEATURE_INTERFACE   0x0101
 179 #define STD_CLEAR_FEATURE_ENDPOINT    0x0102
 180
 181 #define STD_SET_FEATURE_ZERO          0x0300
 182 #define STD_SET_FEATURE_INTERFACE     0x0301
 183 #define STD_SET_FEATURE_ENDPOINT      0x0302
 184
 185 #define STD_SET_ADDRESS               0x0500
 186 #define STD_GET_DESCRIPTOR            0x0680
 187 #define STD_SET_DESCRIPTOR            0x0700
 188 #define STD_GET_CONFIGURATION         0x0880
 189 #define STD_SET_CONFIGURATION         0x0900
 190 #define STD_GET_INTERFACE             0x0A81
 191 #define STD_SET_INTERFACE             0x0B01
 192 #define STD_SYNCH_FRAME               0x0C82
 193
 194 /* CDC Class Specific Request Code */
 195 #define GET_LINE_CODING               0x21A1
 196 #define SET_LINE_CODING               0x2021
 197 #define SET_CONTROL_LINE_STATE        0x2221
 198
 199 typedef struct {
 200         unsigned int dwDTERRate;
 201         char bCharFormat;
 202         char bParityType;
 203         char bDataBits;
 204 } AT91S_CDC_LINE_CODING, *AT91PS_CDC_LINE_CODING;
 205
 206 AT91S_CDC_LINE_CODING line = {
 207         115200, // baudrate
 208         0,      // 1 Stop Bit
 209         0,      // None Parity
 210         8};     // 8 Data bits
 211
 212 void AT91F_CDC_Enumerate();
 213
 214 AT91PS_UDP pUdp = AT91C_BASE_UDP;
 215 byte_t btConfiguration = 0;
 216 byte_t btConnection    = 0;
 217 byte_t btReceiveBank   = AT91C_UDP_RX_DATA_BK0;
 218
 219 //*----------------------------------------------------------------------------
 220 //* \fn    usb_disable
 221 //* \brief This function deactivates the USB device
 222 //*----------------------------------------------------------------------------
 223 void usb_disable() {
 224   // Disconnect the USB device
 225   AT91C_BASE_PIOA->PIO_ODR = GPIO_USB_PU;
 226
 227   // Clear all lingering interrupts
 228   if(pUdp->UDP_ISR & AT91C_UDP_ENDBUSRES) {
 229     pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
 230   }
 231 }
 232
 233 //*----------------------------------------------------------------------------
 234 //* \fn    usb_enable
 235 //* \brief This function Activates the USB device
 236 //*----------------------------------------------------------------------------
 237 void usb_enable() {
 238         // Set the PLL USB Divider
 239         AT91C_BASE_CKGR->CKGR_PLLR |= AT91C_CKGR_USBDIV_1 ;
 240
 241         // Specific Chip USB Initialisation
 242         // Enables the 48MHz USB clock UDPCK and System Peripheral USB Clock
 243         AT91C_BASE_PMC->PMC_SCER = AT91C_PMC_UDP;
 244         AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_UDP);
 245
 246         // Enable UDP PullUp (USB_DP_PUP) : enable & Clear of the corresponding PIO
 247         // Set in PIO mode and Configure in Output
 248         AT91C_BASE_PIOA->PIO_PER = GPIO_USB_PU; // Set in PIO mode
 249         AT91C_BASE_PIOA->PIO_OER = GPIO_USB_PU; // Configure as Output
 250
 251         // Clear for set the Pullup resistor
 252         AT91C_BASE_PIOA->PIO_CODR = GPIO_USB_PU;
 253
 254         // Disconnect and reconnect USB controller for 100ms
 255         usb_disable();
 256
 257         // Wait for a short while
 258         for (volatile size_t i=0; i<0x100000; i++);
 259     //sleep(1);
 260
 261         // Reconnect USB reconnect
 262         AT91C_BASE_PIOA->PIO_SODR = GPIO_USB_PU;
 263         AT91C_BASE_PIOA->PIO_OER = GPIO_USB_PU;
 264 }
 265
 266 //*----------------------------------------------------------------------------
 267 //* \fn    usb_check
 268 //* \brief Test if the device is configured and handle enumeration
 269 //*----------------------------------------------------------------------------
 270 bool usb_check() {
 271         AT91_REG isr = pUdp->UDP_ISR;
 272
 273         if (isr & AT91C_UDP_ENDBUSRES) {
 274                 pUdp->UDP_ICR = AT91C_UDP_ENDBUSRES;
 275                 // reset all endpoints
 276                 pUdp->UDP_RSTEP  = (unsigned int)-1;
 277                 pUdp->UDP_RSTEP  = 0;
 278                 // Enable the function
 279                 pUdp->UDP_FADDR = AT91C_UDP_FEN;
 280                 // Configure endpoint 0
 281                 pUdp->UDP_CSR[0] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_CTRL);
 282         }
 283         else if (isr & AT91C_UDP_EPINT0) {
 284                 pUdp->UDP_ICR = AT91C_UDP_EPINT0;
 285                 AT91F_CDC_Enumerate();
 286         }
 287         return (btConfiguration) ? true : false;
 288 }
 289
 290
 291 bool usb_poll()
 292 {
 293   if (!usb_check()) return false;
 294   return (pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank);
 295 }
 296
 297 /**
 298         In github PR #129, some users appears to get a false positive from
 299         usb_poll, which returns true, but the usb_read operation
 300         still returns 0.
 301         This check is basically the same as above, but also checks
 302         that the length available to read is non-zero, thus hopefully fixes the
 303         bug.
 304 **/
 305 bool usb_poll_validate_length()
 306 {
 307
 308         if (!usb_check()) return false;
 309         if (!(pUdp->UDP_CSR[AT91C_EP_OUT] & btReceiveBank)) return false;
 310         return (pUdp->UDP_CSR[AT91C_EP_OUT] >> 16) >  0;
 311 }
 312
 313 //*----------------------------------------------------------------------------
 314 //* \fn    usb_read
 315 //* \brief Read available data from Endpoint OUT
 316 //*----------------------------------------------------------------------------
 317 uint32_t usb_read(byte_t* data, size_t len) {
 318   byte_t bank = btReceiveBank;
 319         uint32_t packetSize, nbBytesRcv = 0;
 320   uint32_t time_out = 0;
 321
 322         while (len)  {
 323                 if (!usb_check()) break;
 324
 325                 if ( pUdp->UDP_CSR[AT91C_EP_OUT] & bank ) {
 326                         packetSize = MIN(pUdp->UDP_CSR[AT91C_EP_OUT] >> 16, len);
 327       len -= packetSize;
 328                         while(packetSize--)
 329                                 data[nbBytesRcv++] = pUdp->UDP_FDR[AT91C_EP_OUT];
 330                         pUdp->UDP_CSR[AT91C_EP_OUT] &= ~(bank);
 331                         if (bank == AT91C_UDP_RX_DATA_BK0) {
 332                                 bank = AT91C_UDP_RX_DATA_BK1;
 333       } else {
 334                                 bank = AT91C_UDP_RX_DATA_BK0;
 335       }
 336                 }
 337     if (time_out++ == 0x1fff) break;
 338         }
 339
 340         btReceiveBank = bank;
 341         return nbBytesRcv;
 342 }
 343
 344 //*----------------------------------------------------------------------------
 345 //* \fn    usb_write
 346 //* \brief Send through endpoint 2
 347 //*----------------------------------------------------------------------------
 348 uint32_t usb_write(const byte_t* data, const size_t len) {
 349   size_t length = len;
 350         uint32_t cpt = 0;
 351
 352   if (!length) return 0;
 353   if (!usb_check()) return 0;
 354
 355         // Send the first packet
 356         cpt = MIN(length, AT91C_EP_IN_SIZE-1);
 357         length -= cpt;
 358         while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
 359         pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;
 360
 361         while (length) {
 362                 // Fill the second bank
 363                 cpt = MIN(length, AT91C_EP_IN_SIZE-1);
 364                 length -= cpt;
 365                 while (cpt--) pUdp->UDP_FDR[AT91C_EP_IN] = *data++;
 366                 // Wait for the the first bank to be sent
 367                 while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
 368                         if (!usb_check()) return length;
 369     }
 370                 pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
 371                 while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);
 372                 pUdp->UDP_CSR[AT91C_EP_IN] |= AT91C_UDP_TXPKTRDY;
 373         }
 374
 375         // Wait for the end of transfer
 376         while (!(pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP)) {
 377                 if (!usb_check()) return length;
 378   }
 379
 380         pUdp->UDP_CSR[AT91C_EP_IN] &= ~(AT91C_UDP_TXCOMP);
 381         while (pUdp->UDP_CSR[AT91C_EP_IN] & AT91C_UDP_TXCOMP);
 382
 383         return length;
 384 }
 385
 386 //*----------------------------------------------------------------------------
 387 //* \fn    AT91F_USB_SendData
 388 //* \brief Send Data through the control endpoint
 389 //*----------------------------------------------------------------------------
 390 unsigned int csrTab[100] = {0x00};
 391 unsigned char csrIdx = 0;
 392
 393 static void AT91F_USB_SendData(AT91PS_UDP pUdp, const char *pData, uint32_t length) {
 394         uint32_t cpt = 0;
 395         AT91_REG csr;
 396
 397         do {
 398                 cpt = MIN(length, 8);
 399                 length -= cpt;
 400
 401                 while (cpt--)
 402                         pUdp->UDP_FDR[0] = *pData++;
 403
 404                 if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
 405                         pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
 406                         while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
 407                 }
 408
 409                 pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
 410                 do {
 411                         csr = pUdp->UDP_CSR[0];
 412
 413                         // Data IN stage has been stopped by a status OUT
 414                         if (csr & AT91C_UDP_RX_DATA_BK0) {
 415                                 pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
 416                                 return;
 417                         }
 418                 } while ( !(csr & AT91C_UDP_TXCOMP) );
 419
 420         } while (length);
 421
 422         if (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) {
 423                 pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
 424                 while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
 425         }
 426 }
 427
 428 //*----------------------------------------------------------------------------
 429 //* \fn    AT91F_USB_SendZlp
 430 //* \brief Send zero length packet through the control endpoint
 431 //*----------------------------------------------------------------------------
 432 void AT91F_USB_SendZlp(AT91PS_UDP pUdp) {
 433         pUdp->UDP_CSR[0] |= AT91C_UDP_TXPKTRDY;
 434         while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP) );
 435         pUdp->UDP_CSR[0] &= ~(AT91C_UDP_TXCOMP);
 436         while (pUdp->UDP_CSR[0] & AT91C_UDP_TXCOMP);
 437 }
 438
 439 //*----------------------------------------------------------------------------
 440 //* \fn    AT91F_USB_SendStall
 441 //* \brief Stall the control endpoint
 442 //*----------------------------------------------------------------------------
 443 void AT91F_USB_SendStall(AT91PS_UDP pUdp) {
 444         pUdp->UDP_CSR[0] |= AT91C_UDP_FORCESTALL;
 445         while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_ISOERROR) );
 446         pUdp->UDP_CSR[0] &= ~(AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR);
 447         while (pUdp->UDP_CSR[0] & (AT91C_UDP_FORCESTALL | AT91C_UDP_ISOERROR));
 448 }
 449
 450 //*----------------------------------------------------------------------------
 451 //* \fn    AT91F_CDC_Enumerate
 452 //* \brief This function is a callback invoked when a SETUP packet is received
 453 //*----------------------------------------------------------------------------
 454 void AT91F_CDC_Enumerate() {
 455         byte_t bmRequestType, bRequest;
 456         uint16_t wValue, wIndex, wLength, wStatus;
 457
 458         if ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RXSETUP) )
 459                 return;
 460
 461         bmRequestType = pUdp->UDP_FDR[0];
 462         bRequest      = pUdp->UDP_FDR[0];
 463         wValue        = (pUdp->UDP_FDR[0] & 0xFF);
 464         wValue       |= (pUdp->UDP_FDR[0] << 8);
 465         wIndex        = (pUdp->UDP_FDR[0] & 0xFF);
 466         wIndex       |= (pUdp->UDP_FDR[0] << 8);
 467         wLength       = (pUdp->UDP_FDR[0] & 0xFF);
 468         wLength      |= (pUdp->UDP_FDR[0] << 8);
 469
 470         if (bmRequestType & 0x80) {
 471                 pUdp->UDP_CSR[0] |= AT91C_UDP_DIR;
 472                 while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_DIR) );
 473         }
 474         pUdp->UDP_CSR[0] &= ~AT91C_UDP_RXSETUP;
 475         while ( (pUdp->UDP_CSR[0]  & AT91C_UDP_RXSETUP)  );
 476
 477         // Handle supported standard device request Cf Table 9-3 in USB specification Rev 1.1
 478         switch ((bRequest << 8) | bmRequestType) {
 479         case STD_GET_DESCRIPTOR:
 480                 if (wValue == 0x100)       // Return Device Descriptor
 481                         AT91F_USB_SendData(pUdp, devDescriptor, MIN(sizeof(devDescriptor), wLength));
 482                 else if (wValue == 0x200)  // Return Configuration Descriptor
 483                         AT91F_USB_SendData(pUdp, cfgDescriptor, MIN(sizeof(cfgDescriptor), wLength));
 484                 else if ((wValue & 0x300) == 0x300)  // Return String Descriptor
 485                         AT91F_USB_SendData(pUdp, strDescriptor, MIN(sizeof(strDescriptor), wLength));
 486                 else
 487                         AT91F_USB_SendStall(pUdp);
 488                 break;
 489         case STD_SET_ADDRESS:
 490                 AT91F_USB_SendZlp(pUdp);
 491                 pUdp->UDP_FADDR = (AT91C_UDP_FEN | wValue);
 492                 pUdp->UDP_GLBSTATE  = (wValue) ? AT91C_UDP_FADDEN : 0;
 493                 break;
 494         case STD_SET_CONFIGURATION:
 495                 btConfiguration = wValue;
 496                 AT91F_USB_SendZlp(pUdp);
 497                 pUdp->UDP_GLBSTATE  = (wValue) ? AT91C_UDP_CONFG : AT91C_UDP_FADDEN;
 498                 pUdp->UDP_CSR[1] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT) : 0;
 499                 pUdp->UDP_CSR[2] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN)  : 0;
 500                 pUdp->UDP_CSR[3] = (wValue) ? (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_INT_IN)   : 0;
 501                 break;
 502         case STD_GET_CONFIGURATION:
 503                 AT91F_USB_SendData(pUdp, (char *) &(btConfiguration), sizeof(btConfiguration));
 504                 break;
 505         case STD_GET_STATUS_ZERO:
 506                 wStatus = 0;
 507                 AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 508                 break;
 509         case STD_GET_STATUS_INTERFACE:
 510                 wStatus = 0;
 511                 AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 512                 break;
 513         case STD_GET_STATUS_ENDPOINT:
 514                 wStatus = 0;
 515                 wIndex &= 0x0F;
 516                 if ((pUdp->UDP_GLBSTATE & AT91C_UDP_CONFG) && (wIndex <= 3)) {
 517                         wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
 518                         AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 519                 }
 520                 else if ((pUdp->UDP_GLBSTATE & AT91C_UDP_FADDEN) && (wIndex == 0)) {
 521                         wStatus = (pUdp->UDP_CSR[wIndex] & AT91C_UDP_EPEDS) ? 0 : 1;
 522                         AT91F_USB_SendData(pUdp, (char *) &wStatus, sizeof(wStatus));
 523                 }
 524                 else
 525                         AT91F_USB_SendStall(pUdp);
 526                 break;
 527         case STD_SET_FEATURE_ZERO:
 528                 AT91F_USB_SendStall(pUdp);
 529             break;
 530         case STD_SET_FEATURE_INTERFACE:
 531                 AT91F_USB_SendZlp(pUdp);
 532                 break;
 533         case STD_SET_FEATURE_ENDPOINT:
 534                 wIndex &= 0x0F;
 535                 if ((wValue == 0) && wIndex && (wIndex <= 3)) {
 536                         pUdp->UDP_CSR[wIndex] = 0;
 537                         AT91F_USB_SendZlp(pUdp);
 538                 }
 539                 else
 540                         AT91F_USB_SendStall(pUdp);
 541                 break;
 542         case STD_CLEAR_FEATURE_ZERO:
 543                 AT91F_USB_SendStall(pUdp);
 544             break;
 545         case STD_CLEAR_FEATURE_INTERFACE:
 546                 AT91F_USB_SendZlp(pUdp);
 547                 break;
 548         case STD_CLEAR_FEATURE_ENDPOINT:
 549                 wIndex &= 0x0F;
 550                 if ((wValue == 0) && wIndex && (wIndex <= 3)) {
 551                         if (wIndex == 1)
 552                                 pUdp->UDP_CSR[1] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_OUT);
 553                         else if (wIndex == 2)
 554                                 pUdp->UDP_CSR[2] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_BULK_IN);
 555                         else if (wIndex == 3)
 556                                 pUdp->UDP_CSR[3] = (AT91C_UDP_EPEDS | AT91C_UDP_EPTYPE_ISO_IN);
 557                         AT91F_USB_SendZlp(pUdp);
 558                 }
 559                 else
 560                         AT91F_USB_SendStall(pUdp);
 561                 break;
 562
 563         // handle CDC class requests
 564         case SET_LINE_CODING:
 565                 while ( !(pUdp->UDP_CSR[0] & AT91C_UDP_RX_DATA_BK0) );
 566                 pUdp->UDP_CSR[0] &= ~(AT91C_UDP_RX_DATA_BK0);
 567                 AT91F_USB_SendZlp(pUdp);
 568                 break;
 569         case GET_LINE_CODING:
 570                 AT91F_USB_SendData(pUdp, (char *) &line, MIN(sizeof(line), wLength));
 571                 break;
 572         case SET_CONTROL_LINE_STATE:
 573                 btConnection = wValue;
 574                 AT91F_USB_SendZlp(pUdp);
 575                 break;
 576         default:
 577                 AT91F_USB_SendStall(pUdp);
 578             break;
 579         }
 580 }