40-usbtmc-permissions.rules

#
# udev permissions for USB TMC devices
#

#
# The generic way for identifying USB TMC devices would be by first checking
# that bDeviceClass is either 0 (as presribed by USB TMC) or 0xff (as
# implemented by Rigol) and that bDeviceSubClass and bDeviceProtocol are both
# 0xff, and then diving into the interface descriptors and identifying that
# there is one with bInterfaceClass 0xfe (application specific) and
# bInterfaceSubClass 0x03 (USB TMC).
#
# Unfortunately, udev's mechanism of finding this information via usb_id
# (which, oddly enough, seems to be a bit redundant since udev can also see
# the interface itself in some cases), appears to be broken.
#
# We thus fall back to using a list of vendor/product IDs for now :-(
#

#SUBSYSTEM=="usb_device", GOTO="usb_tmc_start"
#SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", GOTO="usb_tmc_start"
#GOTO="usb_tmc_end"
#
#LABEL="usb_tmc_start"
#
## Tektronix TDS2002B oscilloscope <VAB 150420>
#ATTRS{idVendor}=="0699", ATTRS{idProduct}=="0346", MODE="0660", GROUP="dialout"
#
#LABEL="usb_tmc_end"


# à la https://www.raspberrypi.org/forums/viewtopic.php?t=60784&p=485926
# Devices
KERNEL=="usbtmc/*", MODE="0660", GROUP="dialout"
KERNEL=="usbtmc[0-9]*", MODE="0660", GROUP="dialout"