libusb 通信

这两月换了工作，回了成都。

新工作一和设备仪器相关，负责对应的上位机软件开发。

第一个工作就是libusb通信开发和调试。

记录本次libusb的一些代码和调试经历。

#include "libusb.h"
int main(int argc, char* argv[])
{
    QCoreApplication a(argc, argv);

//    return a.exec();

    libusb_context *usb_context = nullptr;
    libusb_device **dev_list;
    libusb_device *dev = NULL;
    libusb_device *dev_temp;
    libusb_device_handle *dev_handle = NULL;

    int ret = -1;
    ssize_t cnt;


    if (ret = libusb_init(&usb_context) < 0)
    {
        printf("init error:%d\n",ret);
        return ret;
    }

    libusb_set_debug(usb_context, 1);
    if (cnt = libusb_get_device_list(usb_context, &dev_list) < 0)
    {
        printf("get device list error:%d\n", cnt);
        return cnt;
    }

    int i = 0;
    while ((dev_temp = dev_list[i++]) != NULL)
    {
        struct libusb_device_descriptor desc;
        int r = libusb_get_device_descriptor(dev_temp, &desc);
        if (r < 0) {
            printf("get device descriptor error:%d\n");
            return NULL;
        }


        printf("%x:%x (bus %d, device %d),bNumberInterfaces:%d\n",
        desc.idVendor, desc.idProduct,
        libusb_get_bus_number(dev_temp), libusb_get_device_address(dev_temp), desc.bNumConfigurations);
        //if ((desc.idProduct == 0xea80) && (desc.idVendor == 0x10c4))
        if ((desc.idProduct == 0xe008) && (desc.idVendor == 0x1a86))
        {
            dev = dev_temp;
            break;
        }
    }
    if (dev == NULL)
    {
        printf("find dev error\n");
        return -1;
    }


    ret = libusb_open(dev, &dev_handle);
    if (dev_handle == NULL)
    {
        printf("open device error:%d\n", ret);
        return ret;
    }


    ret = libusb_kernel_driver_active(dev_handle, 0);
    if (ret == 1)
    {
        printf("driver error, kernel_active ret:%d,%s,", ret, libusb_strerror((libusb_error)ret));
        ret = libusb_detach_kernel_driver(dev_handle, 0);
        if(ret != 0)
            printf("driver error, detach_driver ret:%d,%s,", ret, libusb_strerror((libusb_error)ret));
    }


    if (ret = libusb_claim_interface(dev_handle, 0) < 0)
    {
        printf("claim interface error:%d\n",ret);
        libusb_free_device_list(dev_list, 1);
        libusb_exit(usb_context);
        return ret;
    }

    libusb_reset_device(dev_handle);

    libusb_config_descriptor *config_descriptor_in = NULL, *config_descriptor_out = NULL;
    libusb_get_config_descriptor(dev, 0, &config_descriptor_in);
    libusb_get_config_descriptor(dev, 1, &config_descriptor_out);

    struct libusb_config_descriptor* conf = nullptr;
    int config = 0;
    libusb_get_configuration(dev_handle, &config);
    printf("libusb_get_configuration config:%d.\n", config);
    libusb_set_configuration(dev_handle, 0);




    libusb_get_active_config_descriptor(dev, &conf);
    if(conf){
        printf("bConfigurationValue:%d\n", conf->bConfigurationValue);
        //以下分别打印了输出和输入端点
        for(int q = 0; q < conf->interface->altsetting->bNumEndpoints; ++q){
            printf("conf-bEndpointAddress:0x%02x.\n", conf->interface->altsetting->endpoint[q].bEndpointAddress);
        }
        unsigned char data_rec[128] = "\0";
        int length = 0;
        unsigned char data[1] = {90};
        //ret = libusb_bulk_transfer(dev_handle, config_descriptor_in->interface->altsetting->endpoint->bEndpointAddress, data, 9, &length, 0);
        //ret = libusb_bulk_transfer(dev_handle, 2, data, 4096, &length, 0);//host--------------->device


        unsigned char buf[2] = {0x60, 0x09};
        //控制传输
        ret = libusb_control_transfer(dev_handle, 0x21, 0x9, 0x0300, 0, buf, sizeof(buf), 1000);
        //批量传输
        ret = libusb_bulk_transfer(dev_handle, 0x02, data, 1, &length, 0);//0x02 是输出端点host->device

        for(int i = 0; i < 100000; i++){
            memset(data_rec, 0, 128);
            //断点传输
            ret = libusb_interrupt_transfer(dev_handle, 0x82, data_rec, 128, &length, 0);//0x82 是输入端点device->host
            QString str((const char*)data_rec);
            if(ret == 0){
                for(int i = 0; i < str.size(); ++i){
                    printf("i = %d,receive data：%02x\n",i, str.at(i));
                }
                printf("receive length:%d\n", length);
            }else{
               printf("ret = %d,%s\n", ret, libusb_strerror((libusb_error)16));
            }
        }


        //ret = libusb_bulk_transfer(dev_handle, 0x82, data_rec, 4096, &length, 0);//device--------->host
//        if(ret < 0){
//            printf("ret = %d,%s\n", ret, libusb_strerror((libusb_error)16));
//        }else{
//            printf("ret = %d,receive data：%s\n", ret, data_rec);
//        }

        //{
//            for (int i = 0; i < 100000; i++)
//            {
//                memset(data_rec, 0, 4096);
//                ret = libusb_bulk_transfer(dev_handle, 0x82, data_rec, 4096, &length, 0);//device--------->host
//                if(ret == 0){
//                    printf("i = %d,receive data：%s\n",i, data_rec);
//                }else{
//                    printf("ret = %d,%s\n", ret, libusb_strerror((libusb_error)16));
//                }
//            }
        //}
    }
    else
        printf("get config_descriptor error\n");

    libusb_release_interface(dev_handle, 0);//对应libusb_claim_interface
    libusb_close(dev_handle);
    libusb_free_device_list(dev_list,1);
    libusb_exit(usb_context);

    return 0;
}

 

ps：在测试中有一款设备，需要通过调用libusb_reset_device重置之后，才能获取到对应的productName；所以实际处理是通过获取到的vid和pid找到这个设备，然后对它单独重置。