libusb基本的例子想要

Question

我正在编写用户空间程序,旨在通过usb控制某些设备,所以我决定使用libusb(libusb-1.0)向该设备发送控制消息并从该设备接收响应.

但我不断从我的代码中收到以下一堆错误(即使它是使用'sudo'执行的):

USB error: could not set config 0: Device or resource busy
set configuration: failed
Check that you have permissions to write to 007/012 and, if you don't, that you set up hotplug (http://linux-hotplug.sourceforge.net/) correctly.
USB error: could not claim interface 0: Device or resource busy
claim interface: failed
USB error: error submitting URB: No such file or directory
bulk writing: failed
USB error: error submitting URB: No such file or directory
bulk reading: failed
response was: 

代码是:

usb_dev_handle* find_device ();

int 
main (int argc, char *argv[])
{
    usb_dev_handle* udev;
    int status;
    char request[] = "K1"; // 'ping' command used to check communication
    char response[256];

    udev = find_device ();
    // udev is successfully found here

    status = usb_set_configuration (udev, 0);
    printf ("set configuration: %s\n", status ? "failed" : "passed");

    status = usb_claim_interface (udev, 0);
    printf ("claim interface: %s\n", status ? "failed" : "passed");

    status = usb_bulk_write (udev, 3, request, sizeof (request), 500);
    printf ("bulk writing: %s\n", status ? "failed" : "passed");

    status = usb_bulk_read (udev, 2, response, sizeof (response), 500);
    printf ("bulk reading: %s\n", status ? "failed" : "passed");

    printf ("response was: %s\n", response);

    usb_close (udev);

    return 0;
}

代码有什么问题？它是如何修复的？

操作系统:Ubuntu 10.10

Answer 1

回答这个问题,因为我在同一个操作系统上遇到了这个问题,并且能够以下列方式解决:

下载并编译最新的libusb源代码1.0.8.

以下是我用于声称USB接口0的一些API调用:

libusb_init(NULL);
libusb_open_device_with_vid_pid(NULL, vendor_id, product_id);
libusb_detach_kernel_driver(devh, 0);
libusb_claim_interface(devh, 0);
libusb_close(devh);
libusb_exit(NULL);

以上示例中的变量描述:

static struct libusb_device_handle *devh = NULL;
uint16_t vendor_id;
uint16_t product_id;

要获取供应商ID和产品ID,您可以运行以下命令(例如我的设备信息)

$ lsusb
...
总线001设备013:ID 0930:6544东芝公司金士顿DataTraveler 2.0棒(2GB)
......

粗体冒号分隔的字符串分别包含供应商和产品ID.

如何编译代码:

我使用以下命令编译我的代码:

/ bin/bash libtool --silent --tag = CC --mode = link g ++ -Wall -Wundef -Wunused -Wshadow -D_DEBUG -I ../ libusb -g -O2 -o read read.cpp ../libusb/ libusb-1.0.la -lusb-1.0 -lrt

从提取的libusb-1.0.8目录将libtool复制到编译区域.

希望这可以帮助.

Answer 2

在设置其配置并声明它之前，您不需要 open() 设备吗？