avrdebug.c

ATmega8实现USB接口（采用USB的CDC类

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <usb.h>    /* this is libusb, see http://libusb.sourceforge.net/ */

#define USBDEV_SHARED_VENDOR    0x16c0  /* VOTI */
#define USBDEV_SHARED_CDCPID    0x05e1  /* Obdev's free shared PID for CDC-ACM devices */
/* Use obdev's generic shared VID/PID pair and follow the rules outlined
 * in firmware/usbdrv/USBID-License.txt.
 */
#define USB_VENDOR_STRING       "obdev.at"
#define USB_PRODUCT_STRING      "AVR-Doper"

#define USB_VENDOR_RQ_WRITE     1
#define USB_VENDOR_RQ_READ      2

#ifndef uchar
#define uchar unsigned char
#endif

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

static int  usbGetStringAscii(usb_dev_handle *dev, int index, int langid, char *buf, int buflen)
{
char    buffer[256];
int     rval, i;

    if((rval = usb_control_msg(dev, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR, (USB_DT_STRING << 8) + index, langid, buffer, sizeof(buffer), 1000)) < 0)
        return rval;
    if(buffer[1] != USB_DT_STRING)
        return 0;
    if((uchar)buffer[0] < rval)
        rval = (uchar)buffer[0];
    rval /= 2;
    /* lossy conversion to ISO Latin1 */
    for(i=1;i<rval;i++){
        if(i > buflen)  /* destination buffer overflow */
            break;
        buf[i-1] = buffer[2 * i];
        if(buffer[2 * i + 1] != 0)  /* outside of ISO Latin1 range */
            buf[i-1] = '?';
    }
    buf[i-1] = 0;
    return i-1;
}

#define USB_ERROR_NOTFOUND  1
#define USB_ERROR_ACCESS    2
#define USB_ERROR_IO        3

int usbOpenDevice(usb_dev_handle **device, int vendor, char *vendorName, int product, char *productName)
{
struct usb_bus      *bus;
struct usb_device   *dev;
usb_dev_handle      *handle = NULL;
int                 errorCode = USB_ERROR_NOTFOUND;
static int          didUsbInit = 0;

    if(!didUsbInit){
        didUsbInit = 1;
        usb_init();
    }
    usb_find_busses();
    usb_find_devices();
    for(bus=usb_get_busses(); bus; bus=bus->next){
        for(dev=bus->devices; dev; dev=dev->next){
            if(dev->descriptor.idVendor == vendor && dev->descriptor.idProduct == product){
                char    string[256];
                int     len;
                handle = usb_open(dev); /* we need to open the device in order to query strings */
                if(!handle){
                    errorCode = USB_ERROR_ACCESS;
                    fprintf(stderr, "Warning: cannot open USB device: %s\n", usb_strerror());
                    continue;
                }
                if(vendorName == NULL && productName == NULL){  /* name does not matter */
                    break;
                }
                /* now check whether the names match: */
                len = usbGetStringAscii(handle, dev->descriptor.iManufacturer, 0x0409, string, sizeof(string));
                if(len < 0){
                    errorCode = USB_ERROR_IO;
                    fprintf(stderr, "Warning: cannot query manufacturer for device: %s\n", usb_strerror());
                }else{
                    errorCode = USB_ERROR_NOTFOUND;
                    /* fprintf(stderr, "seen device from vendor ->%s<-\n", string); */
                    if(strcmp(string, vendorName) == 0){
                        len = usbGetStringAscii(handle, dev->descriptor.iProduct, 0x0409, string, sizeof(string));
                        if(len < 0){
                            errorCode = USB_ERROR_IO;
                            fprintf(stderr, "Warning: cannot query product for device: %s\n", usb_strerror());
                        }else{
                            errorCode = USB_ERROR_NOTFOUND;
                            /* fprintf(stderr, "seen product ->%s<-\n", string); */
                            if(strcmp(string, productName) == 0)
                                break;
                        }
                    }
                }
                usb_close(handle);
                handle = NULL;
            }
        }
        if(handle)
            break;
    }
    if(handle != NULL){
        errorCode = 0;
        *device = handle;
    }
    return errorCode;
}

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

/* <c> <LF> <c>         -> <c> LF <c>
 * <c> CR LF <c>        -> <c> LF <c>
 * <c> LF CR <c>        -> <c> LF <c>
 * <c> CR <c>           -> <c> LF <c>
 * <c> CR CR <c>        -> <c> LF LF <c>
 * <c> CR LF CR LF <c>  -> <c> LF LF <c>
 */

static int isCrOrLf(uchar c)
{
    return c == '\r' || c == '\n';
}

static void printChar(uchar c, int needFlush)
{
static char     isStartOfLine = 1;
static uchar    lastChar = 0;
uchar           c1;

    c1 = lastChar;
    lastChar = c;
    if(isCrOrLf(c)){
        if(isCrOrLf(c1)){
            if(c != c1)     /* must be second char of CR LF or LF CR */
                return;
        }
        c = '\n';           /* map all newline chars to LF */
    }
    if(isStartOfLine){
        struct timeval  now;
        struct timezone tz[1];
        struct tm       *tm;
        gettimeofday(&now, tz);
        tm = localtime(&now.tv_sec);
        printf("%02d:%02d:%02d.%03d: ", tm->tm_hour, tm->tm_min, tm->tm_sec, now.tv_usec / 1000);
    }
    putc(c, stdout);
    isStartOfLine = c == '\n';
    if(needFlush && c != '\n'){
        fflush(stdout);
    }
}

static void normalizeAndPrintString(uchar *s, int len)
{
int i;

    for(i = 0; i < len; i++){
        printChar(s[i], (i + 1) >= len);
    }
}

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

int main(int argc, char **argv)
{
usb_dev_handle      *handle = NULL;
unsigned char       buffer[254];
int                 nBytes;

    if(usbOpenDevice(&handle, USBDEV_SHARED_VENDOR, USB_VENDOR_STRING, USBDEV_SHARED_CDCPID, USB_PRODUCT_STRING) != 0){
        fprintf(stderr, "Could not find USB device \"%s\" with vid=0x%x pid=0x%x\n", USB_PRODUCT_STRING, USBDEV_SHARED_VENDOR, USBDEV_SHARED_CDCPID);
        exit(1);
    }
    /* We need not set a configuration and claim an interface to use endpoint 0 */
    /* The following loop does busy polling with 100ms sleeps when no data was
     * received. We can't use an interrupt endpoint because the CDC device class
     * has already consumed them all.
     */
    for(;;){
        nBytes = usb_control_msg(handle, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN, USB_VENDOR_RQ_READ, 0, 0, (char *)buffer, sizeof(buffer), 5000);
        if(nBytes < 0){
            fprintf(stderr, "\nUSB error: %s\nTrying to reconnect...\n", usb_strerror());
            usb_close(handle);
            while(usbOpenDevice(&handle, USBDEV_SHARED_VENDOR, USB_VENDOR_STRING, USBDEV_SHARED_CDCPID, USB_PRODUCT_STRING) != 0){
                sleep(1);
            }
            fprintf(stderr, "Reconnected.\n\n");
            continue;
        }
        if(nBytes > 0){
            normalizeAndPrintString(buffer, nBytes);
        }else{
            usleep(100000); /* 100ms */
        }
    }
    usb_close(handle);
    return 0;
}

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