tctrl —
Tadpole Microcontroller Interface
The tctrl driver provides control over many functions on
  the Tadpole SPARCbook 3 series laptops, via their TS102 chip. The
  microcontroller is used to power the TFT display down when the laptop lid is
  closed and when the screen is blanked by the
  sparc/pnozz(4) driver.
  The tctrl is also used to power the laptop off when
  the reboot(2) system call is
  used with the RB_POWERDOWN flag is set. Power button
  events are forwarded to
  powerd(8). The PCMCIA part of
  the controller is supported by
  sparc/tslot(4).