beaglebone:/sys/kernel/debug/pinctrl/44e10800.pinmux# cat pinmux-pins | grep i2c
pin 86 (44e10958): 4802a000.i2c (GPIO UNCLAIMED) function pinmux_bb_i2c1_pins group pinmux_bb_i2c1_pins
pin 87 (44e1095c): 4802a000.i2c (GPIO UNCLAIMED) function pinmux_bb_i2c1_pins group pinmux_bb_i2c1_pins
root@beaglebone:/sys/kernel/debug/pinctrl/44e10800.pinmux# cat pins
...
pin 86 (44e10958) 00000072 pinctrl-single
pin 87 (44e1095c) 00000072 pinctrl-single
...