usb_linux.c

来自「Android 一些工具」· C语言 代码 · 共 654 行 · 第 1/2 页

    urb->buffer_length = len;

    D("++ write ++\n");

    adb_mutex_lock(&h->lock);
    if(h->dead) {
        res = -1;
        goto fail;
    }
    do {
        res = ioctl(h->desc, USBDEVFS_SUBMITURB, urb);
    } while((res < 0) && (errno == EINTR));

    if(res < 0) {
        goto fail;
    }

    res = -1;
    h->urb_out_busy = 1;
    for(;;) {
        adb_cond_wait(&h->notify, &h->lock);
        if(h->dead) {
            break;
        }
        if(h->urb_out_busy == 0) {
            if(urb->status == 0) {
                res = urb->actual_length;
            }
            break;
        }
    }
fail:
    adb_mutex_unlock(&h->lock);
    D("-- write --\n");
    return res;
}

static int usb_bulk_read(usb_handle *h, void *data, int len)
{
    struct usbdevfs_urb *urb = &h->urb_in;
    struct usbdevfs_urb *out = NULL;
    int res;

    memset(urb, 0, sizeof(*urb));
    urb->type = USBDEVFS_URB_TYPE_BULK;
    urb->endpoint = h->ep_in;
    urb->status = -1;
    urb->buffer = data;
    urb->buffer_length = len;


    adb_mutex_lock(&h->lock);
    if(h->dead) {
        res = -1;
        goto fail;
    }
    do {
        res = ioctl(h->desc, USBDEVFS_SUBMITURB, urb);
    } while((res < 0) && (errno == EINTR));

    if(res < 0) {
        goto fail;
    }

    h->urb_in_busy = 1;
    for(;;) {
        D("[ reap urb - wait ]\n");
        h->reaper_thread = pthread_self();
        adb_mutex_unlock(&h->lock);
        res = ioctl(h->desc, USBDEVFS_REAPURB, &out);
        adb_mutex_lock(&h->lock);
        h->reaper_thread = 0;
        if(h->dead) {
            res = -1;
            break;
        }
        if(res < 0) {
            if(errno == EINTR) {
                continue;
            }
            D("[ reap urb - error ]\n");
            break;
        }
        D("[ urb @%p status = %d, actual = %d ]\n",
            out, out->status, out->actual_length);

        if(out == &h->urb_in) {
            D("[ reap urb - IN complete ]\n");
            h->urb_in_busy = 0;
            if(urb->status == 0) {
                res = urb->actual_length;
            } else {
                res = -1;
            }
            break;
        }
        if(out == &h->urb_out) {
            D("[ reap urb - OUT compelete ]\n");
            h->urb_out_busy = 0;
            adb_cond_broadcast(&h->notify);
        }
    }
fail:
    adb_mutex_unlock(&h->lock);
    return res;
}


int usb_write(usb_handle *h, const void *_data, int len)
{
    unsigned char *data = (unsigned char*) _data;
    int n;
    int need_zero = 0;

    if(h->zero_mask) {
            /* if we need 0-markers and our transfer
            ** is an even multiple of the packet size,
            ** we make note of it
            */
        if(!(len & h->zero_mask)) {
            need_zero = 1;
        }
    }

    while(len > 0) {
        int xfer = (len > 4096) ? 4096 : len;

        n = usb_bulk_write(h, data, xfer);
        if(n != xfer) {
            D("ERROR: n = %d, errno = %d (%s)\n",
                n, errno, strerror(errno));
            return -1;
        }

        len -= xfer;
        data += xfer;
    }

    if(need_zero){
        n = usb_bulk_write(h, _data, 0);
        return n;
    }

    return 0;
}

int usb_read(usb_handle *h, void *_data, int len)
{
    unsigned char *data = (unsigned char*) _data;
    int n;

    D("++ usb_read ++\n");
    while(len > 0) {
        int xfer = (len > 4096) ? 4096 : len;

        D("[ usb read %d fd = %d], fname=%s\n", xfer, h->desc, h->fname);
        n = usb_bulk_read(h, data, xfer);
        D("[ usb read %d ] = %d, fname=%s\n", xfer, n, h->fname);
        if(n != xfer) {
            if((errno == ETIMEDOUT) && (h->desc != -1)) {
                D("[ timeout ]\n");
                if(n > 0){
                    data += n;
                    len -= n;
                }
                continue;
            }
            D("ERROR: n = %d, errno = %d (%s)\n",
                n, errno, strerror(errno));
            return -1;
        }

        len -= xfer;
        data += xfer;
    }

    D("-- usb_read --\n");
    return 0;
}

void usb_kick(usb_handle *h)
{
    D("[ kicking %p (fd = %d) ]\n", h, h->desc);
    adb_mutex_lock(&h->lock);
    if(h->dead == 0) {
        h->dead = 1;

        /* HACK ALERT!
        ** Sometimes we get stuck in ioctl(USBDEVFS_REAPURB).
        ** This is a workaround for that problem.
        */
        if (h->reaper_thread) {
            pthread_kill(h->reaper_thread, SIGALRM);
        }

        /* cancel any pending transactions
        ** these will quietly fail if the txns are not active,
        ** but this ensures that a reader blocked on REAPURB
        ** will get unblocked
        */
        ioctl(h->desc, USBDEVFS_DISCARDURB, &h->urb_in);
        ioctl(h->desc, USBDEVFS_DISCARDURB, &h->urb_out);
        h->urb_in.status = -ENODEV;
        h->urb_out.status = -ENODEV;
        h->urb_in_busy = 0;
        h->urb_out_busy = 0;
        adb_cond_broadcast(&h->notify);
    }
    adb_mutex_unlock(&h->lock);
}

int usb_close(usb_handle *h)
{
    D("[ usb close ... ]\n");
    adb_mutex_lock(&usb_lock);
    h->next->prev = h->prev;
    h->prev->next = h->next;
    h->prev = 0;
    h->next = 0;

    adb_close(h->desc);
    D("[ usb closed %p (fd = %d) ]\n", h, h->desc);
    adb_mutex_unlock(&usb_lock);

    free(h);
    return 0;
}

static void register_device(const char *dev_name,
                            unsigned char ep_in, unsigned char ep_out,
                            int interface,
                            const char *serial, unsigned zero_mask)
{
    usb_handle* usb = 0;
    int n = 0;

        /* Since Linux will not reassign the device ID (and dev_name)
        ** as long as the device is open, we can add to the list here
        ** once we open it and remove from the list when we're finally
        ** closed and everything will work out fine.
        **
        ** If we have a usb_handle on the list 'o handles with a matching
        ** name, we have no further work to do.
        */
    adb_mutex_lock(&usb_lock);
    for(usb = handle_list.next; usb != &handle_list; usb = usb->next){
        if(!strcmp(usb->fname, dev_name)) {
            adb_mutex_unlock(&usb_lock);
            return;
        }
    }
    adb_mutex_unlock(&usb_lock);

    D("[ usb located new device %s (%d/%d/%d) ]\n",
        dev_name, ep_in, ep_out, interface);
    usb = calloc(1, sizeof(usb_handle));
    strcpy(usb->fname, dev_name);
    usb->ep_in = ep_in;
    usb->ep_out = ep_out;
    usb->zero_mask = zero_mask;

    adb_cond_init(&usb->notify, 0);
    adb_mutex_init(&usb->lock, 0);
    /* initialize mark to 1 so we don't get garbage collected after the device scan */
    usb->mark = 1;
    usb->reaper_thread = 0;

    usb->desc = unix_open(usb->fname, O_RDWR);
    if(usb->desc < 0) goto fail;
    D("[ usb open %s fd = %d]\n", usb->fname, usb->desc);
    n = ioctl(usb->desc, USBDEVFS_CLAIMINTERFACE, &interface);
    if(n != 0) goto fail;

        /* add to the end of the active handles */
    adb_mutex_lock(&usb_lock);
    usb->next = &handle_list;
    usb->prev = handle_list.prev;
    usb->prev->next = usb;
    usb->next->prev = usb;
    adb_mutex_unlock(&usb_lock);

    register_usb_transport(usb, serial);
    return;

fail:
    D("[ usb open %s error=%d, err_str = %s]\n",
        usb->fname,  errno, strerror(errno));
    if(usb->desc >= 0) {
        adb_close(usb->desc);
    }
    free(usb);
}

void* device_poll_thread(void* unused)
{
    D("Created device thread\n");
    for(;;) {
            /* XXX use inotify */
        find_usb_device("/dev/bus/usb", register_device);
        kick_disconnected_devices();
        sleep(1);
    }
    return NULL;
}

static void sigalrm_handler(int signo)
{
    // don't need to do anything here
}

void usb_init()
{
    adb_thread_t tid;
    struct sigaction    actions;

    memset(&actions, 0, sizeof(actions));
    sigemptyset(&actions.sa_mask);
    actions.sa_flags = 0;
    actions.sa_handler = sigalrm_handler;
    sigaction(SIGALRM,& actions, NULL);

    if(adb_thread_create(&tid, device_poll_thread, NULL)){
        fatal_errno("cannot create input thread");
    }
}