libusb示例

Posted 2020-10-02 dozeoo

#include <stdio.h>
#include <libusb-1.0/libusb.h>
#include <stdint.h>
#include <string.h>

void processMessage(const uint8_t*);


/*----------------------------------------------------------------------*/
int main(int argc, char*argv[])
{
  int res                      = 0;  /* return codes from libusb functions */
  libusb_device_handle* handle = 0;  /* handle for USB device */
  int kernelDriverDetached     = 0;  /* Set to 1 if kernel driver detached */
  int numBytes                 = 0;  /* Actual bytes transferred. */
  uint8_t buffer[64];                /* 64 byte transfer buffer */

  /* Initialise libusb. */
  res = libusb_init(0);
  if (res != 0)
  {
    fprintf(stderr, "Error initialising libusb.\n");
    return 1;
  }

  /* Get the first device with the matching Vendor ID and Product ID. If
   * intending to allow multiple demo boards to be connected at once, you
   * will need to use libusb_get_device_list() instead. Refer to the libusb
   * documentation for details. */
  handle = libusb_open_device_with_vid_pid(0, 0x04d8, 0x0070);
  if (!handle)
  {
    fprintf(stderr, "Unable to open device.\n");
    return 1;
  }

  /* Check whether a kernel driver is attached to interface #0. If so, we‘ll 
   * need to detach it.
   */
  if (libusb_kernel_driver_active(handle, 0))
  {
    res = libusb_detach_kernel_driver(handle, 0);
    if (res == 0)
    {
      kernelDriverDetached = 1;
    }
    else
    {
      fprintf(stderr, "Error detaching kernel driver.\n");
      return 1;
    }
  }

  /* Claim interface #0. */
  res = libusb_claim_interface(handle, 0);
  if (res != 0)
  {
    fprintf(stderr, "Error claiming interface.\n");
    return 1;
  }


  /* We can now send and receive messages. For example, set normal mode. */
  memset(buffer, 0, 64);
  buffer[58] = 0;      /* CANCTRL = Normal mode. */
  buffer[60] = 0x02;   /* SPI command = Write.   */
  buffer[61] = 0x0f;   /* Register = CANCTRL     */
  buffer[62] = 0;      /* Data = 0 (normal mode) */
  
  /* Send the message to endpoint 1 with a 100ms timeout. */
  res = libusb_interrupt_transfer(handle, 1, buffer, 64, &numBytes, 100);
  if (res == 0)
  {
    printf("%d bytes transmitted successfully.\n", numBytes);
  }
  else
  {
    fprintf(stderr, "Error sending message to device.\n");
  }


  /* Listen for a message. Note that for a normal application you‘ll need 
   * to use asynchronous mode because we can‘t predict when messages will be
   * available. This involves setting up a callback function to handle incoming
   * messages - refer to libusb documentation. */

  /* Wait up to 5 seconds for a message to arrive on endpoint 0x81. */
  res = libusb_interrupt_transfer(handle, 0x81, buffer, 64, &numBytes, 5000);
  if (0 == res)
  {
    if (numBytes == 64)
    {
      processMessage(buffer);
    }
    else
    {
      printf("Received %d bytes, expected 64.\n", numBytes);
    }
  }
  else
  {
    fprintf(stderr, "Error receiving message.\n");
  }

  /* Release interface #0. */
  res = libusb_release_interface(handle, 0);
  if (0 != res)
  {
    fprintf(stderr, "Error releasing interface.\n");
  }

  /* If we detached a kernel driver from interface #0 earlier, we‘ll now 
   * need to attach it again.  */
  if (kernelDriverDetached)
  {
    libusb_attach_kernel_driver(handle, 0);
  }

  /* Shutdown libusb. */
  libusb_exit(0);

  return 0;
}


/*----------------------------------------------------------------------*/
void processMessage(const uint8_t* buffer)
{
  unsigned index = 0;

  /* Most significant bit set indicates a CAN message is present. */
  while(buffer[index] & 0x80)
  {
    unsigned extendedID = buffer[index] & 0x20;
    unsigned rtr        = buffer[index] & 0x10;
    unsigned dataLength = buffer[index] & 0x0f;
    unsigned canID      = 0;

    ++index;

    if (extendedID)  /* 29 bit identifier */
    {
      canID = buffer[index] << 21;
      ++index;
      canID |= (((buffer[index] & 0xe0 >> 5) | 
            (buffer[index] & 0x03)) << 16);
      ++index;
      canID |= (buffer[index] << 8);
      ++index;
      canID |= (buffer[index]);
      ++index;
    }
    else /* standard 11 bit identifier */
    {
      canID      = buffer[index] << 3;
      ++index;
      canID |= ((buffer[index] >> 1) & 7);
      ++index;
    }

    printf("CAN ID: 0x%x [%s] ", canID,
        extendedID ? "extended" : "standard");

    if (rtr)
    {
      printf("RTR\n");
    }
    else
    {
      unsigned i = 0;
      for (i = 0; i < dataLength; ++i)
      {
        printf("0x%02x ", buffer[index]);
        ++index;
      }
      printf("\n");
    }
  }

  printf("CAN Status:      0x%02x\n", buffer[57]);
  printf("Transmit Errors: %u\n", buffer[55]);
  printf("Receive Errors:  %u\n", buffer[56]);

  /* If the command was read, we have received the result. */
  if (buffer[60] == 0x03)
  {
    printf("Read from register 0x%02x returned 0x%02x\n",
        buffer[61], buffer[62]);
  }
}

View Code

#include <stdio.h>    
#include <stdlib.h>    
#include <sys/types.h>    
#include <string.h>    
#include </usr/local/include/libusb-1.0/libusb.h>    


#define BULK_EP_OUT     0x82    
#define BULK_EP_IN      0x08    

int interface_ref = 0;    
int alt_interface,interface_number;    

int print_configuration(struct libusb_device_handle *hDevice,struct libusb_config_descriptor *config)    
{    
    char *data;    
    int index;    

    data = (char *)malloc(512);    
    memset(data,0,512);    

    index = config->iConfiguration;    

    libusb_get_string_descriptor_ascii(hDevice,index,data,512);    

    printf("\nInterface Descriptors: ");    
    printf("\n\tNumber of Interfaces : %d",config->bNumInterfaces);    
    printf("\n\tLength : %d",config->bLength);    
    printf("\n\tDesc_Type : %d",config->bDescriptorType);    
    printf("\n\tConfig_index : %d",config->iConfiguration);    
    printf("\n\tTotal length : %lu",config->wTotalLength);    
    printf("\n\tConfiguration Value  : %d",config->bConfigurationValue);    
    printf("\n\tConfiguration Attributes : %d",config->bmAttributes);    
    printf("\n\tMaxPower(mA) : %d\n",config->MaxPower);    

    free(data);    
    data = NULL;    
    return 0;    
}    

struct libusb_endpoint_descriptor* active_config(struct libusb_device *dev,struct libusb_device_handle *handle)    
{    
    struct libusb_device_handle *hDevice_req;    
    struct libusb_config_descriptor *config;    
    struct libusb_endpoint_descriptor *endpoint;    
    int altsetting_index,interface_index=0,ret_active;    
    int i,ret_print;    

    hDevice_req = handle;    

    ret_active = libusb_get_active_config_descriptor(dev,&config);    
    ret_print = print_configuration(hDevice_req,config);    

    for(interface_index=0;interface_index<config->bNumInterfaces;interface_index++)    
    {    
        const struct libusb_interface *iface = &config->interface[interface_index];    
        for(altsetting_index=0;altsetting_index<iface->num_altsetting;altsetting_index++)    
        {    
            const struct libusb_interface_descriptor *altsetting = &iface->altsetting[altsetting_index];    

            int endpoint_index;    
            for(endpoint_index=0;endpoint_index<altsetting->bNumEndpoints;endpoint_index++)    
            {    
                const struct libusb_endpoint_desriptor *ep = &altsetting->endpoint[endpoint_index];    
                endpoint = ep;      
                alt_interface = altsetting->bAlternateSetting;    
                interface_number = altsetting->bInterfaceNumber;    
            }    

            printf("\nEndPoint Descriptors: ");    
            printf("\n\tSize of EndPoint Descriptor : %d",endpoint->bLength);    
            printf("\n\tType of Descriptor : %d",endpoint->bDescriptorType);    
            printf("\n\tEndpoint Address : 0x0%x",endpoint->bEndpointAddress);    
            printf("\n\tMaximum Packet Size: %x",endpoint->wMaxPacketSize);    
            printf("\n\tAttributes applied to Endpoint: %d",endpoint->bmAttributes);    
            printf("\n\tInterval for Polling for data Tranfer : %d\n",endpoint->bInterval);    
        }    
    }    
    libusb_free_config_descriptor(NULL);    
    return endpoint;    
}    

int main(void)    
{    
    int r = 1;    
    struct libusb_device **devs;    
    struct libusb_device_handle *handle = NULL, *hDevice_expected = NULL;    
    struct libusb_device *dev,*dev_expected;    

    struct libusb_device_descriptor desc;    
    struct libusb_endpoint_descriptor *epdesc;    
    struct libusb_interface_descriptor *intdesc;    

    ssize_t cnt;    
    int e = 0,config2;    
    int i = 0,index;    
    char str1[64], str2[64];    
    char found = 0;    

// Init libusb     
    r = libusb_init(NULL);    
    if(r < 0)    
    {    
        printf("\nfailed to initialise libusb\n");    
        return 1;    
    }    
    else    
        printf("\nInit Successful!\n");    

// Get a list os USB devices    
    cnt = libusb_get_device_list(NULL, &devs);    
    if (cnt < 0)    
    {    
        printf("\nThere are no USB devices on bus\n");    
        return -1;    
    }    
    printf("\nDevice Count : %d\n-------------------------------\n",cnt);    

    while ((dev = devs[i++]) != NULL)    
    {    
        r = libusb_get_device_descriptor(dev, &desc);    
        if (r < 0)    
            {    
            printf("failed to get device descriptor\n");    
            libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            break;    
        }    

        e = libusb_open(dev,&handle);    
        if (e < 0)    
        {    
            printf("error opening device\n");    
            libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            break;    
        }    

        printf("\nDevice Descriptors: ");    
        printf("\n\tVendor ID : %x",desc.idVendor);    
        printf("\n\tProduct ID : %x",desc.idProduct);    
        printf("\n\tSerial Number : %x",desc.iSerialNumber);    
        printf("\n\tSize of Device Descriptor : %d",desc.bLength);    
        printf("\n\tType of Descriptor : %d",desc.bDescriptorType);    
        printf("\n\tUSB Specification Release Number : %d",desc.bcdUSB);    
        printf("\n\tDevice Release Number : %d",desc.bcdDevice);    
        printf("\n\tDevice Class : %d",desc.bDeviceClass);    
        printf("\n\tDevice Sub-Class : %d",desc.bDeviceSubClass);    
        printf("\n\tDevice Protocol : %d",desc.bDeviceProtocol);    
        printf("\n\tMax. Packet Size : %d",desc.bMaxPacketSize0);    
        printf("\n\tNo. of Configuraions : %d\n",desc.bNumConfigurations);    

        e = libusb_get_string_descriptor_ascii(handle, desc.iManufacturer, (unsigned char*) str1, sizeof(str1));    
        if (e < 0)    
        {    
        libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            break;    
        }    
        printf("\nManufactured : %s",str1);    

        e = libusb_get_string_descriptor_ascii(handle, desc.iProduct, (unsigned char*) str2, sizeof(str2));    
        if(e < 0)    
        {    
        libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            break;    
        }    
        printf("\nProduct : %s",str2);    
        printf("\n----------------------------------------");    

        if(desc.idVendor == 0xffff && desc.idProduct == 0x4)    
        {    
        found = 1;    
        break;    
        }    
    }//end of while    
    if(found == 0)    
    {    
        printf("\nDevice NOT found\n");    
        libusb_free_device_list(devs,1);    
        libusb_close(handle);    
        return 1;    
    }    
    else    
    {    
        printf("\nDevice found");    
        dev_expected = dev;    
        hDevice_expected = handle;    
    }    

    e = libusb_get_configuration(handle,&config2);    
    if(e!=0)    
    {    
        printf("\n***Error in libusb_get_configuration\n");    
        libusb_free_device_list(devs,1);    
        libusb_close(handle);    
        return -1;    
    }    
    printf("\nConfigured value : %d",config2);    

    if(config2 != 1)    
    {    
        libusb_set_configuration(handle, 1);    
        if(e!=0)    
        {    
            printf("Error in libusb_set_configuration\n");    
            libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            return -1;    
        }    
        else    
            printf("\nDevice is in configured state!");    
    }    

    libusb_free_device_list(devs, 1);    

    if(libusb_kernel_driver_active(handle, 0) == 1)    
    {    
        printf("\nKernel Driver Active");    
        if(libusb_detach_kernel_driver(handle, 0) == 0)    
            printf("\nKernel Driver Detached!");    
        else    
        {    
            printf("\nCouldn‘t detach kernel driver!\n");    
            libusb_free_device_list(devs,1);    
            libusb_close(handle);    
            return -1;    
        }    
    }    

    e = libusb_claim_interface(handle, 0);    
    if(e < 0)    
    {    
        printf("\nCannot Claim Interface");    
        libusb_free_device_list(devs,1);    
        libusb_close(handle);    
        return -1;    
    }    
    else    
        printf("\nClaimed Interface\n");    

    active_config(dev_expected,hDevice_expected);    

    //   Communicate     

    char *my_string, *my_string1;    
    int transferred = 0;    
    int received = 0;    
    int length = 0;    

    my_string = (char *)malloc(nbytes + 1);    
    my_string1 = (char *)malloc(nbytes + 1);    

    memset(my_string,‘\0‘,64);    
    memset(my_string1,‘\0‘,64);    

    strcpy(my_string,"prasad divesd");    
    length = strlen(my_string);    

    printf("\nTo be sent : %s",my_string);    

    e = libusb_bulk_transfer(handle,BULK_EP_IN,my_string,length,&transferred,0);    
    if(e == 0 && transferred == length)    
    {    
        printf("\nWrite successful!");    
        printf("\nSent %d bytes with string: %s\n", transferred, my_string);    
    }    
    else    
        printf("\nError in write! e = %d and transferred = %d\n",e,transferred);    

    sleep(3);    
    i = 0;    

    for(i = 0; i < length; i++)    
    {    
        e = libusb_bulk_transfer(handle,BULK_EP_OUT,my_string1,64,&received,0);  //64 : Max Packet Lenght    
        if(e == 0)    
        {    
            printf("\nReceived: ");    
            printf("%c",my_string1[i]);    //will read a string from lcp2148
            sleep(1);    
        }    
        else    
        {    
            printf("\nError in read! e = %d and received = %d\n",e,received);    
            return -1;    
        }    
    }    


    e = libusb_release_interface(handle, 0);    

    libusb_close(handle);    
    libusb_exit(NULL);    

    printf("\n");    
    return 0;    
}    

View Code