usbdrv.c

USBasp

uchar       flags = USB_FLG_MSGPTR_IS_ROM;

    SWITCH_START(rq->wValue.bytes[1])
    SWITCH_CASE(USBDESCR_DEVICE)    /* 1 */
        GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_DEVICE, usbDescriptorDevice)
    SWITCH_CASE(USBDESCR_CONFIG)    /* 2 */
        GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_CONFIGURATION, usbDescriptorConfiguration)
    SWITCH_CASE(USBDESCR_STRING)    /* 3 */
#if USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC
        if(USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_RAM)
            flags = 0;
        len = usbFunctionDescriptor(rq);
#else   /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
        SWITCH_START(rq->wValue.bytes[0])
        SWITCH_CASE(0)
            GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_0, usbDescriptorString0)
        SWITCH_CASE(1)
            GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_VENDOR, usbDescriptorStringVendor)
        SWITCH_CASE(2)
            GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_PRODUCT, usbDescriptorStringDevice)
        SWITCH_CASE(3)
            GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_STRING_SERIAL_NUMBER, usbDescriptorStringSerialNumber)
        SWITCH_DEFAULT
            if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
                len = usbFunctionDescriptor(rq);
            }
        SWITCH_END
#endif  /* USB_CFG_DESCR_PROPS_STRINGS & USB_PROP_IS_DYNAMIC */
#if USB_CFG_DESCR_PROPS_HID_REPORT  /* only support HID descriptors if enabled */
    SWITCH_CASE(USBDESCR_HID)       /* 0x21 */
        GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID, usbDescriptorConfiguration + 18)
    SWITCH_CASE(USBDESCR_HID_REPORT)/* 0x22 */
        GET_DESCRIPTOR(USB_CFG_DESCR_PROPS_HID_REPORT, usbDescriptorHidReport)
#endif
    SWITCH_DEFAULT
        if(USB_CFG_DESCR_PROPS_UNKNOWN & USB_PROP_IS_DYNAMIC){
            len = usbFunctionDescriptor(rq);
        }
    SWITCH_END
    usbMsgFlags = flags;
    return len;
}

/* ------------------------------------------------------------------------- */

/* usbDriverSetup() is similar to usbFunctionSetup(), but it's used for
 * standard requests instead of class and custom requests.
 */
static inline usbMsgLen_t usbDriverSetup(usbRequest_t *rq)
{
uchar   len  = 0, *dataPtr = usbTxBuf + 9;  /* there are 2 bytes free space at the end of the buffer */
uchar   value = rq->wValue.bytes[0];
#if USB_CFG_IMPLEMENT_HALT
uchar   index = rq->wIndex.bytes[0];
#endif

    dataPtr[0] = 0; /* default reply common to USBRQ_GET_STATUS and USBRQ_GET_INTERFACE */
    SWITCH_START(rq->bRequest)
    SWITCH_CASE(USBRQ_GET_STATUS)           /* 0 */
        uchar recipient = rq->bmRequestType & USBRQ_RCPT_MASK;  /* assign arith ops to variables to enforce byte size */
        if(USB_CFG_IS_SELF_POWERED && recipient == USBRQ_RCPT_DEVICE)
            dataPtr[0] =  USB_CFG_IS_SELF_POWERED;
#if USB_CFG_IMPLEMENT_HALT
        if(recipient == USBRQ_RCPT_ENDPOINT && index == 0x81)   /* request status for endpoint 1 */
            dataPtr[0] = usbTxLen1 == USBPID_STALL;
#endif
        dataPtr[1] = 0;
        len = 2;
#if USB_CFG_IMPLEMENT_HALT
    SWITCH_CASE2(USBRQ_CLEAR_FEATURE, USBRQ_SET_FEATURE)    /* 1, 3 */
        if(value == 0 && index == 0x81){    /* feature 0 == HALT for endpoint == 1 */
            usbTxLen1 = rq->bRequest == USBRQ_CLEAR_FEATURE ? USBPID_NAK : USBPID_STALL;
            usbResetDataToggling();
        }
#endif
    SWITCH_CASE(USBRQ_SET_ADDRESS)          /* 5 */
        usbNewDeviceAddr = value;
        USB_SET_ADDRESS_HOOK();
    SWITCH_CASE(USBRQ_GET_DESCRIPTOR)       /* 6 */
        len = usbDriverDescriptor(rq);
        goto skipMsgPtrAssignment;
    SWITCH_CASE(USBRQ_GET_CONFIGURATION)    /* 8 */
        dataPtr = &usbConfiguration;  /* send current configuration value */
        len = 1;
    SWITCH_CASE(USBRQ_SET_CONFIGURATION)    /* 9 */
        usbConfiguration = value;
        usbResetStall();
    SWITCH_CASE(USBRQ_GET_INTERFACE)        /* 10 */
        len = 1;
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
    SWITCH_CASE(USBRQ_SET_INTERFACE)        /* 11 */
        usbResetDataToggling();
        usbResetStall();
#endif
    SWITCH_DEFAULT                          /* 7=SET_DESCRIPTOR, 12=SYNC_FRAME */
        /* Should we add an optional hook here? */
    SWITCH_END
    usbMsgPtr = dataPtr;
skipMsgPtrAssignment:
    return len;
}

/* ------------------------------------------------------------------------- */

/* usbProcessRx() is called for every message received by the interrupt
 * routine. It distinguishes between SETUP and DATA packets and processes
 * them accordingly.
 */
static inline void usbProcessRx(uchar *data, uchar len)
{
usbRequest_t    *rq = (void *)data;

/* usbRxToken can be:
 * 0x2d 00101101 (USBPID_SETUP for setup data)
 * 0xe1 11100001 (USBPID_OUT: data phase of setup transfer)
 * 0...0x0f for OUT on endpoint X
 */
    DBG2(0x10 + (usbRxToken & 0xf), data, len); /* SETUP=1d, SETUP-DATA=11, OUTx=1x */
    USB_RX_USER_HOOK(data, len)
#if USB_CFG_IMPLEMENT_FN_WRITEOUT
    if(usbRxToken < 0x10){  /* OUT to endpoint != 0: endpoint number in usbRxToken */
        usbFunctionWriteOut(data, len);
        return;
    }
#endif
    if(usbRxToken == (uchar)USBPID_SETUP){
        if(len != 8)    /* Setup size must be always 8 bytes. Ignore otherwise. */
            return;
        usbMsgLen_t replyLen;
        usbTxBuf[0] = USBPID_DATA0;         /* initialize data toggling */
        usbTxLen = USBPID_NAK;              /* abort pending transmit */
        usbMsgFlags = 0;
        uchar type = rq->bmRequestType & USBRQ_TYPE_MASK;
        if(type != USBRQ_TYPE_STANDARD){    /* standard requests are handled by driver */
            replyLen = usbFunctionSetup(data);
        }else{
            replyLen = usbDriverSetup(rq);
        }
#if USB_CFG_IMPLEMENT_FN_READ || USB_CFG_IMPLEMENT_FN_WRITE
        if(replyLen == USB_NO_MSG){         /* use user-supplied read/write function */
            /* do some conditioning on replyLen, but on IN transfers only */
            if((rq->bmRequestType & USBRQ_DIR_MASK) != USBRQ_DIR_HOST_TO_DEVICE){
                if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
                    replyLen = rq->wLength.bytes[0];
                }else{
                    replyLen = rq->wLength.word;
                }
            }
            usbMsgFlags = USB_FLG_USE_USER_RW;
        }else   /* The 'else' prevents that we limit a replyLen of USB_NO_MSG to the maximum transfer len. */
#endif
        if(sizeof(replyLen) < sizeof(rq->wLength.word)){ /* help compiler with optimizing */
            if(!rq->wLength.bytes[1] && replyLen > rq->wLength.bytes[0])    /* limit length to max */
                replyLen = rq->wLength.bytes[0];
        }else{
            if(replyLen > rq->wLength.word)     /* limit length to max */
                replyLen = rq->wLength.word;
        }
        usbMsgLen = replyLen;
    }else{  /* usbRxToken must be USBPID_OUT, which means data phase of setup (control-out) */
#if USB_CFG_IMPLEMENT_FN_WRITE
        if(usbMsgFlags & USB_FLG_USE_USER_RW){
            uchar rval = usbFunctionWrite(data, len);
            if(rval == 0xff){   /* an error occurred */
                usbTxLen = USBPID_STALL;
            }else if(rval != 0){    /* This was the final package */
                usbMsgLen = 0;  /* answer with a zero-sized data packet */
            }
        }
#endif
    }
}

/* ------------------------------------------------------------------------- */

/* This function is similar to usbFunctionRead(), but it's also called for
 * data handled automatically by the driver (e.g. descriptor reads).
 */
static uchar usbDeviceRead(uchar *data, uchar len)
{
    if(len > 0){    /* don't bother app with 0 sized reads */
#if USB_CFG_IMPLEMENT_FN_READ
        if(usbMsgFlags & USB_FLG_USE_USER_RW){
            len = usbFunctionRead(data, len);
        }else
#endif
        {
            uchar i = len, *r = usbMsgPtr;
            if(usbMsgFlags & USB_FLG_MSGPTR_IS_ROM){    /* ROM data */
                do{
                    uchar c = USB_READ_FLASH(r);    /* assign to char size variable to enforce byte ops */
                    *data++ = c;
                    r++;
                }while(--i);
            }else{  /* RAM data */
                do{
                    *data++ = *r++;
                }while(--i);
            }
            usbMsgPtr = r;
        }
    }
    return len;
}

/* ------------------------------------------------------------------------- */

/* usbBuildTxBlock() is called when we have data to transmit and the
 * interrupt routine's transmit buffer is empty.
 */
static inline void usbBuildTxBlock(void)
{
usbMsgLen_t wantLen;
uchar       len;

    wantLen = usbMsgLen;
    if(wantLen > 8)
        wantLen = 8;
    usbMsgLen -= wantLen;
    usbTxBuf[0] ^= USBPID_DATA0 ^ USBPID_DATA1; /* DATA toggling */
    len = usbDeviceRead(usbTxBuf + 1, wantLen);
    if(len <= 8){           /* valid data packet */
        usbCrc16Append(&usbTxBuf[1], len);
        len += 4;           /* length including sync byte */
        if(len < 12)        /* a partial package identifies end of message */
            usbMsgLen = USB_NO_MSG;
    }else{
        len = USBPID_STALL;   /* stall the endpoint */
        usbMsgLen = USB_NO_MSG;
    }
    usbTxLen = len;
    DBG2(0x20, usbTxBuf, len-1);
}

/* ------------------------------------------------------------------------- */

static inline void usbHandleResetHook(uchar notResetState)
{
#ifdef USB_RESET_HOOK
static uchar    wasReset;
uchar           isReset = !notResetState;

    if(wasReset != isReset){
        USB_RESET_HOOK(isReset);
        wasReset = isReset;
    }
#endif
}

/* ------------------------------------------------------------------------- */

USB_PUBLIC void usbPoll(void)
{
schar   len;
uchar   i;

    len = usbRxLen - 3;
    if(len >= 0){
/* We could check CRC16 here -- but ACK has already been sent anyway. If you
 * need data integrity checks with this driver, check the CRC in your app
 * code and report errors back to the host. Since the ACK was already sent,
 * retries must be handled on application level.
 * unsigned crc = usbCrc16(buffer + 1, usbRxLen - 3);
 */
        usbProcessRx(usbRxBuf + USB_BUFSIZE + 1 - usbInputBufOffset, len);
#if USB_CFG_HAVE_FLOWCONTROL
        if(usbRxLen > 0)    /* only mark as available if not inactivated */
            usbRxLen = 0;
#else
        usbRxLen = 0;       /* mark rx buffer as available */
#endif
    }
    if(usbTxLen & 0x10){    /* transmit system idle */
        if(usbMsgLen != USB_NO_MSG){    /* transmit data pending? */
            usbBuildTxBlock();
        }
    }
    for(i = 20; i > 0; i--){
        uchar usbLineStatus = USBIN & USBMASK;
        if(usbLineStatus != 0)  /* SE0 has ended */
            goto isNotReset;
    }
    /* RESET condition, called multiple times during reset */
    usbNewDeviceAddr = 0;
    usbDeviceAddr = 0;
    usbResetStall();
    DBG1(0xff, 0, 0);
isNotReset:
    usbHandleResetHook(i);
}

/* ------------------------------------------------------------------------- */

USB_PUBLIC void usbInit(void)
{
#if USB_INTR_CFG_SET != 0
    USB_INTR_CFG |= USB_INTR_CFG_SET;
#endif
#if USB_INTR_CFG_CLR != 0
    USB_INTR_CFG &= ~(USB_INTR_CFG_CLR);
#endif
    USB_INTR_ENABLE |= (1 << USB_INTR_ENABLE_BIT);
    usbResetDataToggling();
#if USB_CFG_HAVE_INTRIN_ENDPOINT && !USB_CFG_SUPPRESS_INTR_CODE
    usbTxLen1 = USBPID_NAK;
#if USB_CFG_HAVE_INTRIN_ENDPOINT3
    usbTxLen3 = USBPID_NAK;
#endif
#endif
}

/* ------------------------------------------------------------------------- */