ACPI(4) | Device Drivers Manual | ACPI(4)

# NAME

`acpi` — Advanced Configuration and Power Interface

# SYNOPSIS

`acpi0 at bios?`

# DESCRIPTION

The `acpi` driver provides basic support for ACPI including loading ACPI tables from the firmware, parsing and interpreting AML code, event handling, suspending and powering off, and attaching device drivers. Userland may access `acpi` by using the apm(4) device.

The following devices can attach to `acpi`:

abl(4)
  Apple backlight support
acpiac(4)
  ACPI AC adapter
acpials(4)
  ACPI ambient light sensor
acpiasus(4)
  ASUS ACPI hotkeys
acpibat(4)
  ACPI control method battery
acpibtn(4)
  ACPI button
acpicbkbd(4)
  Chromebook keyboard backlight
acpicmos(4)
  CMOS memory manager
acpicpu(4)
  ACPI processor power and performance state
acpidock(4)
  ACPI docking station
acpiec(4)
  ACPI embedded controller
acpige(4)
  ACPI generic event device
acpihid(4)
  ACPI HID event and 5-button array
acpihpet(4)
  ACPI high precision event timer
acpihve(4)
  Hyper-V entropy
acpimadt(4)
  ACPI APIC configuration
acpimcfg(4)
  ACPI PCI Express configuration space
acpipci(4)
  ACPI PCI host bridge
acpiprt(4)
  ACPI PCI routing table configuration
acpipwrres(4)
  ACPI power resources
acpisbs(4)
  ACPI Smart Battery subsystem
acpisony(4)
  Sony ACPI control
acpisurface(4)
  Microsoft Surface Book ACPI support
acpithinkpad(4)
  IBM/Lenovo ThinkPad ACPI support
acpitimer(4)
  ACPI power management timer
acpitoshiba(4)
  Toshiba ACPI support
acpitz(4)
  ACPI thermal zone
acpivideo(4)
  ACPI video
acpivout(4)
  ACPI video output
acpiwmi(4)
  ACPI WMI interface
ahci(4)
  Advanced Host Controller Interface for Serial ATA
aibs(4)
  ASUSTeK AI Booster ACPI ATK0110 temperature, voltage, and fan sensor
amdgpio(4)
  AMD GPIO controller
ampchwm(4)
  Ampere Altra fine-grained power telemetry
aplgpio(4)
  Intel Apollo Lake GPIO controller
asmc(4)
  Apple System Management Controller (SMC)
bse(4)
  Broadcom GENET 10/100/1Gb Ethernet device
bytgpio(4)
  Intel Bay Trail GPIO controller
ccp(4)
  AMD cryptographic co-processor
chvgpio(4)
  Intel Cherry View GPIO controller
dwgpio(4)
  Synopsys DesignWare GPIO controller
dwiic(4)
  Synopsys DesignWare I2C controller
glkgpio(4)
  Intel Gemini Lake GPIO controller
imxiic(4)
  i.MX onboard I2C controller
intelpmc(4)
  Intel power management controller
iosf(4)
  Intel OnChip System Fabric device
ipmi(4)
  Intelligent Platform Management Interface driver
pchgpio(4)
  Intel PCH GPIO controller
pckbc(4)
  Keyboard controller
pluart(4)
  ARM PrimeCell PL011 UART
qcgpio(4)
  Qualcomm Snapdragon GPIO controller
qciic(4)
  Qualcomm Snapdragon GENI I2C controller
sdhc(4)
  SD Host Controller
tpm(4)
  Trusted Platform Module device
ufshci(4)
  Universal Flash Storage Host Controller Interface

# FILES

/dev/apm
  Power management data device. May only be opened read-only. May be opened by multiple concurrent users.
/dev/apmctl
  Power management control device. May be opened read-write or write-only. May only be opened by one user at a time. An attempt to open the file when in use will fail, returning `EBUSY`.

# SEE ALSO

apm(4), intro(4)

# HISTORY

The `acpi` driver first appeared in OpenBSD 3.8.

# AUTHORS

The `acpi` driver was written by Thorsten Lockert <tholo@sigmasoft.com> and Jordan Hargrave <jordan@openbsd.org>.

May 20, 2025 | Debian