FTDI D2XX FT_DEVICE_LIST_INFO_NODE structure is all zeros

Question

I am trying to get a Matlab MEX to run in Linux. It uses FTDI's D2XX library v1.3.6 (Documentation).

FT_CreateDeviceInfoList(&ftdi_count) gives me an ftdi_count of 1, so the FTDI chip is detected.

However, when iterating through the device list from FT_GetDeviceInfoList(device_list, &ftdi_count), my FT_DEVICE_LIST_INFO_NODE structure is all zeros, so obviously the code cannot find the device with the description it is looking for:

(gdb) p *p_device
$3 = {Flags = 1, Type = 3, ID = 0, LocId = 0, SerialNumber = '\000' <repeats 15 times>, 
  Description = '\000' <repeats 63 times>, ftHandle = 0x0}

My first guess was that udev wasn't set up. But the problem persists with

SUBSYSTEM=="usb", ATTR{idVendor}=="0403", ATTR{idProduct}="6014", MODE="0666"

lsusb -v has access to the values:

Bus 001 Device 012: ID 0403:6014 Future Technology Devices International, Ltd FT232H Single HS USB-UART/FIFO IC
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x0403 Future Technology Devices International, Ltd
  idProduct          0x6014 FT232H Single HS USB-UART/FIFO IC
  bcdDevice            9.00
  iManufacturer           1 FTDI
  iProduct                2 [company that provided me with their] Kit v3
  iSerial                 3 FT266WVA
  bNumConfigurations      1
[...]

What can I do to make the FTDI functions work?

score 0 · Answer 1 · answered Jun 13 '17 at 18:52

The problem is that Linux automatically loads the VCP driver (ftdi_sio).

In the Question How can I get Linux device with FTDI D2XX driver API, Akira shows a udev script to from A blog unload that driver. I modified it to work with my FT232H chip, which has only one port:

ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6014", RUN+="/bin/sh -c 'echo -n $kernel:1.0 > /sys/bus/usb/drivers/ftdi_sio/unbind;'"

FTDI D2XX FT_DEVICE_LIST_INFO_NODE structure is all zeros

1 Answers1