SUBSYSTEM=="i2c-dev", KERNEL=="i2c-[0-9]*", ATTRS{class}=="0x03*", TAG+="uaccess"
SUBSYSTEM=="dri", KERNEL=="card[0-9]*", TAG+="uaccess"
#
# The following rule mimics 60-i2c-tools.rules, which may not be installed.
# It is expected that some distributions will enable this rule. others not, 
# depending on their packaging policy.
#
# There are situations where granting i2c group permissions is more robust
# than tag uacces. Some systems have been seen to exhibit transitory EACCES 
# errors on return from sleep when tag uaccess is relied on. 
# individual users may wish to make a copy of this file as 
# /etc/udev/rules.d/60-ddcutil-i2c-tools.rules and edit the file to enable 
# the rule.
#
#SUBSYSTEM=="i2c-dev", KERNEL=="i2c-[0-9]*", GROUP="i2c", MODE="0660"