[Libusb-devel] error sending control message: No such file or directory

[Michael K. <Mic...@SO...>]

Hello,

i would like to write a userspace driver for a unsupported USB device.
I've got some information from the manufactor how to acces the device.
At the moment i make my first steps with libusb 0.1.5.

Based on the testlibusb.c i try to make a control transfer to the default
Endpoint 0. I can open the device, but when i send the control message, 
i got errorcode -1. I enabled the debug output and libusb says the
following:

USB error: error sending control message: No such file or directory

Program was started as root. Has anybody an idea what type of file or
directory
is needed? /proc/bus/usb/... is mounted and i can see the files in it.

Below you can find the modified sourcecode and the program output.
With the control message i would like to read 8 Bytes from the USB device
with
a Vendor RequestType from Endpoint 0.
  
Thank you very much for your help in advance!

Michael

------------------------------ C-Sourcecode -------------------------------
main (void)
{
  struct usb_bus *bus;
  struct usb_device *dev;
  struct usb_dev_handle *dev_handle;
  int x, c;
  unsigned char buffer[5000];

  for (x = 0; x < 5000; x++)
    buffer[x] = 0xAA;

  usb_set_debug (2);

  usb_init ();

  usb_find_busses ();
  usb_find_devices ();

  printf ("bus/device  idVendor/idProduct\n");
  for (bus = usb_busses; bus; bus = bus->next)
    {
      for (dev = bus->devices; dev; dev = dev->next)
	{
	  int i;

	  printf ("%s/%s     %04X/%04X\n", bus->dirname, dev->filename,
		  dev->descriptor.idVendor, dev->descriptor.idProduct);

	  if ((dev->descriptor.idVendor ==
	       0x0e50) & (dev->descriptor.idProduct == 0x0001))
	    {
	      printf ("** Device Found **\n");

	      dev_handle = usb_open (dev);

	      if (!dev_handle)
		printf ("Open failed!\n");
	      else
		printf ("Open Successful!\n ");


	      if (usb_set_configuration (dev_handle, 1) == 0)
		printf ("Set the config\n");
	      else
		printf ("Error setting configuration\n");

	      c=usb_control_msg (dev_handle,
				 USB_ENDPOINT_IN | USB_TYPE_VENDOR |
				 USB_RECIP_ENDPOINT, 'O', 0x0000, 0x0000,
				 buffer, 8, 5000);
		
	      printf ("control_msg returncode=%d\n", c);

	      for (x = 0; x < 8; x++)
		printf ("%2X ", buffer[x]);

	      printf ("\n");

	    }

	  if (!dev->config)
	    {
	      printf ("  Couldn't retrieve descriptors\n");
	      continue;
	    }

	  for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
	    print_configuration (&dev->config[i]);
	}
    }

  return 0;
}


------------------------------ Program Output
-------------------------------
usb_set_debug: Setting debugging level to 2 (on)
usb_os_init: Found USB VFS at /proc/bus/usb
usb_find_busses: Skipping non bus directory devices
usb_find_busses: Skipping non bus directory drivers
usb_find_busses: Found 001
usb_find_devices_on_bus: Found 001 on 001
usb_find_devices_on_bus: Found 030 on 001
bus/device  idVendor/idProduct
001/030     0E50/0001
** Device Found **
Open Successful!
 Set the config
USB error: error sending control message: No such file or directory
control_msg returncode=-1
AA AA AA AA AA AA AA AA 
  wTotalLength:         18
  bNumInterfaces:       1
  bConfigurationValue:  1
  iConfiguration:       0
  bmAttributes:         80h
  MaxPower:             4
    bInterfaceNumber:   0
    bAlternateSetting:  0
    bNumEndpoints:      0
    bInterfaceClass:    0
    bInterfaceSubClass: 0
    bInterfaceProtocol: 0
    iInterface:         0
001/001     0000/0000
  wTotalLength:         25
  bNumInterfaces:       1
  bConfigurationValue:  1
  iConfiguration:       0
  bmAttributes:         40h
  MaxPower:             0
    bInterfaceNumber:   0
    bAlternateSetting:  0
    bNumEndpoints:      1
    bInterfaceClass:    9
    bInterfaceSubClass: 0
    bInterfaceProtocol: 0
    iInterface:         0
      bEndpointAddress: 81h
      bmAttributes:     03h
      wMaxPacketSize:   8
      bInterval:        255
      bRefresh:         0
      bSynchAddress:    0