bfin-jtag does not work with ICE-1000 on BF537

I have an Analog Devices ICE-1000 USB device. I need to read/write the flash memory on a BF537 device so I can get u-boot loaded, and I expected that the bfin-jtag program would be able to do that (it looks like a re-branded urjtag). However, when I try to connect, I get the following:

jtag> cable ICE-100B

error: Couldn't connect to suitable USB device.
error: not found: no USB connections

The jtag device is listed in dmesg:

[ 196.999107] usb 1-1: new high-speed USB device number 2 using xhci_hcd
[ 197.017758] usb 1-1: New USB device found, idVendor=064b, idProduct=0617
[ 197.017761] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 197.017763] usb 1-1: Product: Blackfin USB Device
[ 197.017764] usb 1-1: Manufacturer: Analog Devices, Inc.

However, I don't know if there's a kernel module that needs to be loaded for it or something. Can anyone help be figure this out? Suggestions for other ways to get u-boot loaded are welcome as well. I tried UART boot via ldrviewer, and that didn't work either.