walkblank.github.io

static char device_open(void) { struct usb_bus *bus; struct usb_device dev; usb_dev_handle device_handle;

static int USBInitDone = 0; int i, iret = 0, ret;

if (USBInitDone != 0) return 0;

    // initialize USB subsystem
    usb_init();
    usb_set_debug(0);
    usb_find_busses();
    usb_find_devices();

    for (i=0; i<MAX_PORTNUM; ++i)
      usbhnd[i] = NULL;

    DEBUGP("libusb demo begin, qiushui_007 test ok\n");
    for (bus = usb_get_busses(); bus; bus = bus->next) {
            for (dev = bus->devices; dev; dev = dev->next) {
                    DEBUGP("%s/%s     %04X/%04X\n", bus->dirname, dev->filename,
                                            dev->descriptor.idVendor, dev->descriptor.idProduct);
                    if (dev->descriptor.idVendor == VENDOR_ID && dev->descriptor.idProduct == PRODUCT_ID) {
                            DEBUGP("Find device \n");

                            device_handle = usb_open(dev);
                            iret = 1;
                            if (device_handle == NULL) {
                                    iret = 0;
                            }
                            else {
                                    ret = 0;
                                    ret = usb_detach_kernel_driver_np(device_handle, 0);
                                    DEBUGP("usb_detach_kernel_driver_np: ret %d\n", ret);

                                    ret = usb_set_configuration(device_handle, 1);
                                    DEBUGP("usb_set_configuration: ret %d\n", ret);
                                    if (ret < 0) {
                                             perror("Failed to set configuration\n");
                                             usb_close(device_handle);
                                device_handle = NULL;
                                    }

            /* 在操作设备前是必须调用的, 0是指用默认的设备 */
            ret = usb_claim_interface(device_handle, 0);
            DEBUGP("usb_claim_interface: ret %d\n", ret);
                  if (ret < 0) {
                    perror("Cannot claim interface");
                    usb_close(device_handle);
                    device_handle = NULL;

                    return 0;
                  }

                                    break;
                            }
                    }
            }
    }

    USBInitDone = 1 ;
    usbhnd[g_portnum] = device_handle;

    return iret;

}

执行结果: //---- DS2490测试 usb_detach_kernel_driver_np: ret -61 usb_set_configuration: ret 0 usb_claim_interface: ret 0

//--- CR95HF测试 usb_detach_kernel_driver_np: ret -22 usb_set_configuration: ret 0 usb_claim_interface: ret -2 Cannot claim interface: No such file or directory