firmware/usbdrv/usbdrv.c

   1 /* Name: usbdrv.c
   2  * Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers
   3  * Author: Christian Starkjohann
   4  * Creation Date: 2004-12-29
   5  * Tabsize: 4
   6  * Copyright: (c) 2005 by OBJECTIVE DEVELOPMENT Software GmbH
   7  * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
   8  * This Revision: $Id$
   9  */
  10
  11 #include "usbportability.h"
  12 #include "usbdrv.h"
  13 #include "oddebug.h"
  14
  15 /*
  16 General Description:
  17 This module implements the C-part of the USB driver. See usbdrv.h for a
  18 documentation of the entire driver.
  19 */
  20
  21 /* ------------------------------------------------------------------------- */
  22
  23 /* raw USB registers / interface to assembler code: */
  24 uchar usbRxBuf[2*USB_BUFSIZE];  /* raw RX buffer: PID, 8 bytes data, 2 bytes CRC */
  25 uchar       usbInputBufOffset;  /* offset in usbRxBuf used for low level receiving */
  26 uchar       usbDeviceAddr;      /* assigned during enumeration, defaults to 0 */
  27 uchar       usbNewDeviceAddr;   /* device ID which should be set after status phase */
  28 uchar       usbConfiguration;   /* currently selected configuration. Administered by driver, but not used */
  29 volatile schar usbRxLen;        /* = 0; number of bytes in usbRxBuf; 0 means free, -1 for flow control */
  30 uchar       usbCurrentTok;      /* last token received or endpoint number for last OUT token if != 0 */
  31 uchar       usbRxToken;         /* token for data we received; or endpont number for last OUT */
  32 volatile uchar usbTxLen = USBPID_NAK;   /* number of bytes to transmit with next IN token or handshake token */
  33 uchar       usbTxBuf[USB_BUFSIZE];/* data to transmit with next IN, free if usbTxLen contains handshake token */
  34 #if USB_COUNT_SOF
  35 volatile uchar  usbSofCount;    /* incremented by assembler module every SOF */
  36 #endif
  37 #if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
  38 usbTxStatus_t  usbTxStatus1;
  39 #   if USB_CFG_HAVE_INTRIN_ENDPOINT3
  40 usbTxStatus_t  usbTxStatus3;
  41 #   endif
  42 #endif
  43 #if USB_CFG_CHECK_DATA_TOGGLING
  44 uchar       usbCurrentDataToken;/* when we check data toggling to ignore duplicate packets */
  45 #endif
  46
  47 /* USB status registers / not shared with asm code */
  48 uchar               *usbMsgPtr;     /* data to transmit next -- ROM or RAM address */
  49 static usbMsgLen_t  usbMsgLen = USB_NO_MSG; /* remaining number of bytes */
  50 static uchar        usbMsgFlags;    /* flag values see below */
  51
  52 #define USB_FLG_MSGPTR_IS_ROM   (1<<6)
  53 #define USB_FLG_USE_USER_RW     (1<<7)
  54
  55 /*
  56 optimizing hints:
  57 - do not post/pre inc/dec integer values in operations
  58 - assign value of USB_READ_FLASH() to register variables and don't use side effects in arg
  59 - use narrow scope for variables which should be in X/Y/Z register
  60 - assign char sized expressions to variables to force 8 bit arithmetics
  61 */
  62
  63 /* -------------------------- String Descriptors --------------------------- */
  64
  65 #if USB_CFG_DESCR_PROPS_STRINGS == 0
  66
  67 #if USB_CFG_DESCR_PROPS_STRING_0 == 0
  68 #undef USB_CFG_DESCR_PROPS_STRING_0
  69 #define USB_CFG_DESCR_PROPS_STRING_0    sizeof(usbDescriptorString0)
  70 PROGMEM const char usbDescriptorString0[] = { /* language descriptor */
  71     4,          /* sizeof(usbDescriptorString0): length of descriptor in bytes */
  72     3,          /* descriptor type */
  73     0x09, 0x04, /* language index (0x0409 = US-English) */
  74 };
  75 #endif
  76
  77 #if USB_CFG_DESCR_PROPS_STRING_VENDOR == 0 && USB_CFG_VENDOR_NAME_LEN
  78 #undef USB_CFG_DESCR_PROPS_STRING_VENDOR
  79 #define USB_CFG_DESCR_PROPS_STRING_VENDOR   sizeof(usbDescriptorStringVendor)
  80 PROGMEM const int  usbDescriptorStringVendor[] = {
  81     USB_STRING_DESCRIPTOR_HEADER(USB_CFG_VENDOR_NAME_LEN),
  82     USB_CFG_VENDOR_NAME
  83 };
  84 #endif
  85
  86 #if USB_CFG_DESCR_PROPS_STRING_PRODUCT == 0 && USB_CFG_DEVICE_NAME_LEN
  87 #undef USB_CFG_DESCR_PROPS_STRING_PRODUCT
  88 #define USB_CFG_DESCR_PROPS_STRING_PRODUCT   sizeof(usbDescriptorStringDevice)
  89 PROGMEM const int  usbDescriptorStringDevice[] = {
  90     USB_STRING_DESCRIPTOR_HEADER(USB_CFG_DEVICE_NAME_LEN),
  91     USB_CFG_DEVICE_NAME
  92 };
  93 #endif
  94
  95 #if USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER == 0 && USB_CFG_SERIAL_NUMBER_LEN
  96 #undef USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER
  97 #define USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER    sizeof(usbDescriptorStringSerialNumber)
  98 PROGMEM const int usbDescriptorStringSerialNumber[] = {
  99     USB_STRING_DESCRIPTOR_HEADER(USB_CFG_SERIAL_NUMBER_LEN),
 100     USB_CFG_SERIAL_NUMBER
 101 };
 102 #endif
 103
 104 #endif  /* USB_CFG_DESCR_PROPS_STRINGS == 0 */
 105
 106 /* --------------------------- Device Descriptor --------------------------- */
 107
 108 #if USB_CFG_DESCR_PROPS_DEVICE == 0
 109 #undef USB_CFG_DESCR_PROPS_DEVICE
 110 #define USB_CFG_DESCR_PROPS_DEVICE  sizeof(usbDescriptorDevice)
 111 PROGMEM const char usbDescriptorDevice[] = {    /* USB device descriptor */
 112     18,         /* sizeof(usbDescriptorDevice): length of descriptor in bytes */
 113     USBDESCR_DEVICE,        /* descriptor type */
 114     0x10, 0x01,             /* USB version supported */
 115     USB_CFG_DEVICE_CLASS,
 116     USB_CFG_DEVICE_SUBCLASS,
 117     0,                      /* protocol */
 118     8,                      /* max packet size */
 119     /* the following two casts affect the first byte of the constant only, but
 120      * that's sufficient to avoid a warning with the default values.
 121      */
 122     (char)USB_CFG_VENDOR_ID,/* 2 bytes */
 123     (char)USB_CFG_DEVICE_ID,/* 2 bytes */
 124     USB_CFG_DEVICE_VERSION, /* 2 bytes */
 125     USB_CFG_DESCR_PROPS_STRING_VENDOR != 0 ? 1 : 0,         /* manufacturer string index */
 126     USB_CFG_DESCR_PROPS_STRING_PRODUCT != 0 ? 2 : 0,        /* product string index */
 127     USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER != 0 ? 3 : 0,  /* serial number string index */
 128     1,          /* number of configurations */
 129 };
 130 #endif
 131
 132 /* ----------------------- Configuration Descriptor ------------------------ */
 133
 134 #if USB_CFG_DESCR_PROPS_HID_REPORT != 0 && USB_CFG_DESCR_PROPS_HID == 0
 135 #undef USB_CFG_DESCR_PROPS_HID
 136 #define USB_CFG_DESCR_PROPS_HID     9   /* length of HID descriptor in config descriptor below */
 137 #endif
 138
 139 #if USB_CFG_DESCR_PROPS_CONFIGURATION == 0
 140 #undef USB_CFG_DESCR_PROPS_CONFIGURATION
 141 #define USB_CFG_DESCR_PROPS_CONFIGURATION   sizeof(usbDescriptorConfiguration)
 142 PROGMEM const char usbDescriptorConfiguration[] = {    /* USB configuration descriptor */
 143     9,          /* sizeof(usbDescriptorConfiguration): length of descriptor in bytes */
 144     USBDESCR_CONFIG,    /* descriptor type */
 145     18 + 7 * USB_CFG_HAVE_INTRIN_ENDPOINT + 7 * USB_CFG_HAVE_INTRIN_ENDPOINT3 +
 146                 (USB_CFG_DESCR_PROPS_HID & 0xff), 0,
 147                 /* total length of data returned (including inlined descriptors) */
 148     1,          /* number of interfaces in this configuration */
 149     1,          /* index of this configuration */
 150     0,          /* configuration name string index */
 151 #if USB_CFG_IS_SELF_POWERED
 152     (1 << 7) | USBATTR_SELFPOWER,       /* attributes */
 153 #else
 154     (1 << 7),                           /* attributes */
 155 #endif
 156     USB_CFG_MAX_BUS_POWER/2,            /* max USB current in 2mA units */
 157 /* interface descriptor follows inline: */
 158     9,          /* sizeof(usbDescrInterface): length of descriptor in bytes */
 159     USBDESCR_INTERFACE, /* descriptor type */
 160     0,          /* index of this interface */
 161     0,          /* alternate setting for this interface */
 162     USB_CFG_HAVE_INTRIN_ENDPOINT + USB_CFG_HAVE_INTRIN_ENDPOINT3, /* endpoints excl 0: number of endpoint descriptors to follow */
 163     USB_CFG_INTERFACE_CLASS,
 164     USB_CFG_INTERFACE_SUBCLASS,
 165     USB_CFG_INTERFACE_PROTOCOL,
 166     0,          /* string index for interface */
 167 #if (USB_CFG_DESCR_PROPS_HID & 0xff)    /* HID descriptor */
 168     9,          /* sizeof(usbDescrHID): length of descriptor in bytes */
 169     USBDESCR_HID,   /* descriptor type: HID */
 170     0x01, 0x01, /* BCD representation of HID version */
 171     0x00,       /* target country code */
 172     0x01,       /* number of HID Report (or other HID class) Descriptor infos to follow */
 173     0x22,       /* descriptor type: report */
 174     USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH, 0,  /* total length of report descriptor */
 175 #endif
 176 #if USB_CFG_HAVE_INTRIN_ENDPOINT    /* endpoint descriptor for endpoint 1 */
 177     7,          /* sizeof(usbDescrEndpoint) */
 178     USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
 179     (char)0x81, /* IN endpoint number 1 */
 180     0x03,       /* attrib: Interrupt endpoint */
 181     8, 0,       /* maximum packet size */
 182     USB_CFG_INTR_POLL_INTERVAL, /* in ms */
 183 #endif
 184 #if USB_CFG_HAVE_INTRIN_ENDPOINT3   /* endpoint descriptor for endpoint 3 */
 185     7,          /* sizeof(usbDescrEndpoint) */
 186     USBDESCR_ENDPOINT,  /* descriptor type = endpoint */
 187     (char)(0x80 | USB_CFG_EP3_NUMBER), /* IN endpoint number 3 */
 188     0x03,       /* attrib: Interrupt endpoint */
 189     8, 0,       /* maximum packet size */
 190     USB_CFG_INTR_POLL_INTERVAL, /* in ms */
 191 #endif
 192 };
 193 #endif
 194
 195 /* ------------------------------------------------------------------------- */
 196
 197 static inline void  usbResetDataToggling(void)
 198 {
 199 #if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
 200     USB_SET_DATATOKEN1(USB_INITIAL_DATATOKEN);  /* reset data toggling for interrupt endpoint */
 201 #   if USB_CFG_HAVE_INTRIN_ENDPOINT3
 202     USB_SET_DATATOKEN3(USB_INITIAL_DATATOKEN);  /* reset data toggling for interrupt endpoint */
 203 #   endif
 204 #endif
 205 }
 206
 207 static inline void  usbResetStall(void)
 208 {
 209 #if USB_CFG_IMPLEMENT_HALT && USB_CFG_HAVE_INTRIN_ENDPOINT
 210         usbTxLen1 = USBPID_NAK;
 211 #if USB_CFG_HAVE_INTRIN_ENDPOINT3
 212         usbTxLen3 = USBPID_NAK;
 213 #endif
 214 #endif
 215 }
 216
 217 /* ------------------------------------------------------------------------- */
 218
 219 #if !USB_CFG_SUPPRESS_INTR_CODE
 220 #if USB_CFG_HAVE_INTRIN_ENDPOINT
 221 static void usbGenericSetInterrupt(uchar *data, uchar len, usbTxStatus_t *txStatus)
 222 {
 223 uchar   *p;
 224 char    i;
 225
 226 #if USB_CFG_IMPLEMENT_HALT
 227     if(usbTxLen1 == USBPID_STALL)
 228         return;
 229 #endif
 230     if(txStatus->len & 0x10){   /* packet buffer was empty */
 231         txStatus->buffer[0] ^= USBPID_DATA0 ^ USBPID_DATA1; /* toggle token */
 232     }else{
 233         txStatus->len = USBPID_NAK; /* avoid sending outdated (overwritten) interrupt data */
 234     }
 235     p = txStatus->buffer + 1;
 236     i = len;
 237     do{                         /* if len == 0, we still copy 1 byte, but that's no problem */
 238         *p++ = *data++;
 239     }while(--i > 0);            /* loop control at the end is 2 bytes shorter than at beginning */
 240     usbCrc16Append(&txStatus->buffer[1], len);
 241     txStatus->len = len + 4;    /* len must be given including sync byte */
 242     DBG2(0x21 + (((int)txStatus >> 3) & 3), txStatus->buffer, len + 3);
 243 }
 244
 245 USB_PUBLIC void usbSetInterrupt(uchar *data, uchar len)
 246 {
 247     usbGenericSetInterrupt(data, len, &usbTxStatus1);
 248 }
 249 #endif
 250
 251 #if USB_CFG_HAVE_INTRIN_ENDPOINT3
 252 USB_PUBLIC void usbSetInterrupt3(uchar *data, uchar len)
 253 {
 254     usbGenericSetInterrupt(data, len, &usbTxStatus3);
 255 }
 256 #endif
 257 #endif /* USB_CFG_SUPPRESS_INTR_CODE */
 258
 259 /* ------------------ utilities for code following below ------------------- */
 260
 261 /* Use defines for the switch statement so that we can choose between an
 262  * if()else if() and a switch/case based implementation. switch() is more
 263  * efficient for a LARGE set of sequential choices, if() is better in all other
 264  * cases.
 265  */
 266 #if USB_CFG_USE_SWITCH_STATEMENT
 267 #   define SWITCH_START(cmd)       switch(cmd){{
 268 #   define SWITCH_CASE(value)      }break; case (value):{
 269 #   define SWITCH_CASE2(v1,v2)     }break; case (v1): case(v2):{
 270 #   define SWITCH_CASE3(v1,v2,v3)  }break; case (v1): case(v2): case(v3):{
 271 #   define SWITCH_DEFAULT          }break; default:{
 272 #   define SWITCH_END              }}
 273 #else
 274 #   define SWITCH_START(cmd)       {uchar _cmd = cmd; if(0){
 275 #   define SWITCH_CASE(value)      }else if(_cmd == (value)){
 276 #   define SWITCH_CASE2(v1,v2)     }else if(_cmd == (v1) || _cmd == (v2)){
 277 #   define SWITCH_CASE3(v1,v2,v3)  }else if(_cmd == (v1) || _cmd == (v2) || (_cmd == v3)){
 278 #   define SWITCH_DEFAULT          }else{
 279 #   define SWITCH_END              }}
 280 #endif
 281
 282 #ifndef USB_RX_USER_HOOK
 283 #define USB_RX_USER_HOOK(data, len)
 284 #endif
 285 #ifndef USB_SET_ADDRESS_HOOK
 286 #define USB_SET_ADDRESS_HOOK()
 287 #endif
 288
 289 /* ------------------------------------------------------------------------- */
 290
 291 /* We use if() instead of #if in the macro below because #if can't be used
 292  * in macros and the compiler optimizes constant conditions anyway.
 293  * This may cause problems with undefined symbols if compiled without
 294  * optimizing!
 295  */
 296 #define GET_DESCRIPTOR(cfgProp, staticName)         \
 297     if(cfgProp){                                    \
 298         if((cfgProp) & USB_PROP_IS_RAM)             \
 299             flags = 0;                              \
 300         if((cfgProp) & USB_PROP_IS_DYNAMIC){        \
 301             len = usbFunctionDescriptor(rq);        \
 302         }else{                                      \
 303             len = USB_PROP_LENGTH(cfgProp);         \
 304             usbMsgPtr = (uchar *)(staticName);      \
 305         }                                           \
 306     }
 307
 308 /* usbDriverDescriptor() is similar to usbFunctionDescriptor(), but used
 309  * internally for all types of descriptors.
 310  */
 311 static inline usbMsgLen_t usbDriverDescriptor(usbRequest_t *rq)
 312 {
 313 usbMsgLen_t len = 0;
 314 uchar       flags = USB_FLG_MSGPTR_IS_ROM;
 315
 316     SWITCH_START(rq->wValue.bytes[1])
 317     SWITCH_CASE(USBDESCR_DEVICE)    /* 1 */
 318         GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_DEVICE, usbDescriptorDevice)
 319     SWITCH_CASE(USBDESCR_CONFIG)    /* 2 */
 320         GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_CONFIGURATION, usbDescriptorConfiguration)
 321     SWITCH_CASE(USBDESCR_STRING)    /* 3 */
 322 #if USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC
 323         if(USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_RAM)
 324             flags = 0;
 325         len = usbFunctionDescriptor(rq);
 326 #else   /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
 327         SWITCH_START(rq->wValue.bytes[0])
 328         SWITCH_CASE(0)
 329             GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_0, usbDescriptorString0)
 330         SWITCH_CASE(1)
 331             GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_VENDOR, usbDescriptorStringVendor)
 332         SWITCH_CASE(2)
 333             GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_PRODUCT, usbDescriptorStringDevice)
 334         SWITCH_CASE(3)
 335             GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER, usbDescriptorStringSerialNumber)
 336         SWITCH_DEFAULT
 337             if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
 338                 len = usbFunctionDescriptor(rq);
 339             }
 340         SWITCH_END
 341 #endif  /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
 342 #if USB_CFG_DESCR_PROPS_HID_REPORT  /* only support HID descriptors if enabled */
 343     SWITCH_CASE(USBDESCR_HID)       /* 0x21 */
 344         GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID, usbDescriptorConfiguration + 18)
 345     SWITCH_CASE(USBDESCR_HID_REPORT)/* 0x22 */
 346         GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID_REPORT, usbDescriptorHidReport)
 347 #endif
 348     SWITCH_DEFAULT
 349         if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
 350             len = usbFunctionDescriptor(rq);
 351         }
 352     SWITCH_END
 353     usbMsgFlags = flags;
 354     return len;
 355 }
 356
 357 /* ------------------------------------------------------------------------- */
 358
 359 /* usbDriverSetup() is similar to usbFunctionSetup(), but it's used for
 360  * standard requests instead of class and custom requests.
 361  */
 362 static inline usbMsgLen_t usbDriverSetup(usbRequest_t *rq)
 363 {
 364 usbMsgLen_t len = 0;
 365 uchar   *dataPtr = usbTxBuf + 9;    /* there are 2 bytes free space at the end of the buffer */
 366 uchar   value = rq->wValue.bytes[0];
 367 #if USB_CFG_IMPLEMENT_HALT
 368 uchar   index = rq->wIndex.bytes[0];
 369 #endif
 370
 371     dataPtr[0] = 0; /* default reply common to USBRQ_GET_STATUS and USBRQ_GET_INTERFACE */
 372     SWITCH_START(rq->bRequest)
 373     SWITCH_CASE(USBRQ_GET_STATUS)           /* 0 */
 374         uchar recipient = rq->bmRequestType & USBRQ_RCPT_MASK;  /* assign arith ops to variables to enforce byte size */
 375         if(USB_CFG_IS_SELF_POWERED && recipient == USBRQ_RCPT_DEVICE)
 376             dataPtr[0] =  USB_CFG_IS_SELF_POWERED;
 377 #if USB_CFG_IMPLEMENT_HALT
 378         if(recipient == USBRQ_RCPT_ENDPOINT && index == 0x81)   /* request status for endpoint 1 */
 379             dataPtr[0] = usbTxLen1 == USBPID_STALL;
 380 #endif
 381         dataPtr[1] = 0;
 382         len = 2;
 383 #if USB_CFG_IMPLEMENT_HALT
 384     SWITCH_CASE2(USBRQ_CLEAR_FEATURE, USBRQ_SET_FEATURE)    /* 1, 3 */
 385         if(value == 0 && index == 0x81){    /* feature 0 == HALT for endpoint == 1 */
 386             usbTxLen1 = rq->bRequest == USBRQ_CLEAR_FEATURE ? USBPID_NAK : USBPID_STALL;
 387             usbResetDataToggling();
 388         }
 389 #endif
 390     SWITCH_CASE(USBRQ_SET_ADDRESS)          /* 5 */
 391         usbNewDeviceAddr = value;
 392         USB_SET_ADDRESS_HOOK();
 393     SWITCH_CASE(USBRQ_GET_DESCRIPTOR)       /* 6 */
 394         len = usbDriverDescriptor(rq);
 395         goto skipMsgPtrAssignment;
 396     SWITCH_CASE(USBRQ_GET_CONFIGURATION)    /* 8 */
 397         dataPtr = &usbConfiguration;  /* send current configuration value */
 398         len = 1;
 399     SWITCH_CASE(USBRQ_SET_CONFIGURATION)    /* 9 */
 400         usbConfiguration = value;
 401         usbResetStall();
 402     SWITCH_CASE(USBRQ_GET_INTERFACE)        /* 10 */
 403         len = 1;
 404 #if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
 405     SWITCH_CASE(USBRQ_SET_INTERFACE)        /* 11 */
 406         usbResetDataToggling();
 407         usbResetStall();
 408 #endif
 409     SWITCH_DEFAULT                          /* 7=SET_DESCRIPTOR, 12=SYNC_FRAME */
 410         /* Should we add an optional hook here? */
 411     SWITCH_END
 412     usbMsgPtr = dataPtr;
 413 skipMsgPtrAssignment:
 414     return len;
 415 }
 416
 417 /* ------------------------------------------------------------------------- */
 418
 419 /* usbProcessRx() is called for every message received by the interrupt
 420  * routine. It distinguishes between SETUP and DATA packets and processes
 421  * them accordingly.
 422  */
 423 static inline void usbProcessRx(uchar *data, uchar len)
 424 {
 425 usbRequest_t    *rq = (void *)data;
 426
 427 /* usbRxToken can be:
 428  * 0x2d 00101101 (USBPID_SETUP for setup data)
 429  * 0xe1 11100001 (USBPID_OUT: data phase of setup transfer)
 430  * 0...0x0f for OUT on endpoint X
 431  */
 432     DBG2(0x10 + (usbRxToken & 0xf), data, len + 2); /* SETUP=1d, SETUP-DATA=11, OUTx=1x */
 433     USB_RX_USER_HOOK(data, len)
 434 #if USB_CFG_IMPLEMENT_FN_WRITEOUT
 435     if(usbRxToken < 0x10){  /* OUT to endpoint != 0: endpoint number in usbRxToken */
 436         usbFunctionWriteOut(data, len);
 437         return;
 438     }
 439 #endif
 440     if(usbRxToken == (uchar)USBPID_SETUP){
 441         if(len != 8)    /* Setup size must be always 8 bytes. Ignore otherwise. */
 442             return;
 443         usbMsgLen_t replyLen;
 444         usbTxBuf[0] = USBPID_DATA0;         /* initialize data toggling */
 445         usbTxLen = USBPID_NAK;              /* abort pending transmit */
 446         usbMsgFlags = 0;
 447         uchar type = rq->bmRequestType & USBRQ_TYPE_MASK;
 448         if(type != USBRQ_TYPE_STANDARD){    /* standard requests are handled by driver */
 449             replyLen = usbFunctionSetup(data);
 450         }else{
 451             replyLen = usbDriverSetup(rq);
 452         }
 453 #if USB_CFG_IMPLEMENT_FN_READ || USB_CFG_IMPLEMENT_FN_WRITE
 454         if(replyLen == USB_NO_MSG){         /* use user-supplied read/write function */
 455             /* do some conditioning on replyLen, but on IN transfers only */
 456             if((rq->bmRequestType & USBRQ_DIR_MASK) != USBRQ_DIR_HOST_TO_DEVICE){
 457                 if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
 458                     replyLen = rq->wLength.bytes[0];
 459                 }else{
 460                     replyLen = rq->wLength.word;
 461                 }
 462             }
 463             usbMsgFlags = USB_FLG_USE_USER_RW;
 464         }else   /* The 'else' prevents that we limit a replyLen of USB_NO_MSG to the maximum transfer len. */
 465 #endif
 466         if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
 467             if(!rq->wLength.bytes[1] && replyLen > rq->wLength.bytes[0])    /* limit length to max */
 468                 replyLen = rq->wLength.bytes[0];
 469         }else{
 470             if(replyLen > rq->wLength.word)     /* limit length to max */
 471                 replyLen = rq->wLength.word;
 472         }
 473         usbMsgLen = replyLen;
 474     }else{  /* usbRxToken must be USBPID_OUT, which means data phase of setup (control-out) */
 475 #if USB_CFG_IMPLEMENT_FN_WRITE
 476         if(usbMsgFlags & USB_FLG_USE_USER_RW){
 477             uchar rval = usbFunctionWrite(data, len);
 478             if(rval == 0xff){   /* an error occurred */
 479                 usbTxLen = USBPID_STALL;
 480             }else if(rval != 0){    /* This was the final package */
 481                 usbMsgLen = 0;  /* answer with a zero-sized data packet */
 482             }
 483         }
 484 #endif
 485     }
 486 }
 487
 488 /* ------------------------------------------------------------------------- */
 489
 490 /* This function is similar to usbFunctionRead(), but it's also called for
 491  * data handled automatically by the driver (e.g. descriptor reads).
 492  */
 493 static uchar usbDeviceRead(uchar *data, uchar len)
 494 {
 495     if(len > 0){    /* don't bother app with 0 sized reads */
 496 #if USB_CFG_IMPLEMENT_FN_READ
 497         if(usbMsgFlags & USB_FLG_USE_USER_RW){
 498             len = usbFunctionRead(data, len);
 499         }else
 500 #endif
 501         {
 502             uchar i = len, *r = usbMsgPtr;
 503             if(usbMsgFlags & USB_FLG_MSGPTR_IS_ROM){    /* ROM data */
 504                 do{
 505                     uchar c = USB_READ_FLASH(r);    /* assign to char size variable to enforce byte ops */
 506                     *data++ = c;
 507                     r++;
 508                 }while(--i);
 509             }else{  /* RAM data */
 510                 do{
 511                     *data++ = *r++;
 512                 }while(--i);
 513             }
 514             usbMsgPtr = r;
 515         }
 516     }
 517     return len;
 518 }
 519
 520 /* ------------------------------------------------------------------------- */
 521
 522 /* usbBuildTxBlock() is called when we have data to transmit and the
 523  * interrupt routine's transmit buffer is empty.
 524  */
 525 static inline void usbBuildTxBlock(void)
 526 {
 527 usbMsgLen_t wantLen;
 528 uchar       len;
 529
 530     wantLen = usbMsgLen;
 531     if(wantLen > 8)
 532         wantLen = 8;
 533     usbMsgLen -= wantLen;
 534     usbTxBuf[0] ^= USBPID_DATA0 ^ USBPID_DATA1; /* DATA toggling */
 535     len = usbDeviceRead(usbTxBuf + 1, wantLen);
 536     if(len <= 8){           /* valid data packet */
 537         usbCrc16Append(&usbTxBuf[1], len);
 538         len += 4;           /* length including sync byte */
 539         if(len < 12)        /* a partial package identifies end of message */
 540             usbMsgLen = USB_NO_MSG;
 541     }else{
 542         len = USBPID_STALL;   /* stall the endpoint */
 543         usbMsgLen = USB_NO_MSG;
 544     }
 545     usbTxLen = len;
 546     DBG2(0x20, usbTxBuf, len-1);
 547 }
 548
 549 /* ------------------------------------------------------------------------- */
 550
 551 static inline void usbHandleResetHook(uchar notResetState)
 552 {
 553 #ifdef USB_RESET_HOOK
 554 static uchar    wasReset;
 555 uchar           isReset = !notResetState;
 556
 557     if(wasReset != isReset){
 558         USB_RESET_HOOK(isReset);
 559         wasReset = isReset;
 560     }
 561 #else
 562     notResetState = notResetState;  // avoid compiler warning
 563 #endif
 564 }
 565
 566 /* ------------------------------------------------------------------------- */
 567
 568 USB_PUBLIC void usbPoll(void)
 569 {
 570 schar   len;
 571 uchar   i;
 572
 573     len = usbRxLen - 3;
 574     if(len >= 0){
 575 /* We could check CRC16 here -- but ACK has already been sent anyway. If you
 576  * need data integrity checks with this driver, check the CRC in your app
 577  * code and report errors back to the host. Since the ACK was already sent,
 578  * retries must be handled on application level.
 579  * unsigned crc = usbCrc16(buffer + 1, usbRxLen - 3);
 580  */
 581         usbProcessRx(usbRxBuf + USB_BUFSIZE + 1 - usbInputBufOffset, len);
 582 #if USB_CFG_HAVE_FLOWCONTROL
 583         if(usbRxLen > 0)    /* only mark as available if not inactivated */
 584             usbRxLen = 0;
 585 #else
 586         usbRxLen = 0;       /* mark rx buffer as available */
 587 #endif
 588     }
 589     if(usbTxLen & 0x10){    /* transmit system idle */
 590         if(usbMsgLen != USB_NO_MSG){    /* transmit data pending? */
 591             usbBuildTxBlock();
 592         }
 593     }
 594     for(i = 20; i > 0; i--){
 595         uchar usbLineStatus = USBIN & USBMASK;
 596         if(usbLineStatus != 0)  /* SE0 has ended */
 597             goto isNotReset;
 598     }
 599     /* RESET condition, called multiple times during reset */
 600     usbNewDeviceAddr = 0;
 601     usbDeviceAddr = 0;
 602     usbResetStall();
 603     DBG1(0xff, 0, 0);
 604 isNotReset:
 605     usbHandleResetHook(i);
 606 }
 607
 608 /* ------------------------------------------------------------------------- */
 609
 610 USB_PUBLIC void usbInit(void)
 611 {
 612 #if USB_INTR_CFG_SET != 0
 613     USB_INTR_CFG |= USB_INTR_CFG_SET;
 614 #endif
 615 #if USB_INTR_CFG_CLR != 0
 616     USB_INTR_CFG &= ~(USB_INTR_CFG_CLR);
 617 #endif
 618     USB_INTR_ENABLE |= (1 << USB_INTR_ENABLE_BIT);
 619     usbResetDataToggling();
 620 #if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
 621     usbTxLen1 = USBPID_NAK;
 622 #if USB_CFG_HAVE_INTRIN_ENDPOINT3
 623     usbTxLen3 = USBPID_NAK;
 624 #endif
 625 #endif
 626 }
 627
 628 /* ------------------------------------------------------------------------- */