# SPDX-License-Identifier: GPL-2.0
#
# ACPI Configuration
#
config ARCH_SUPPORTS_ACPI
bool
menuconfig ACPI
bool "ACPI (Advanced Configuration and Power Interface) Support"
depends on ARCH_SUPPORTS_ACPI
select PNP
select NLS
select CRC32
default y if X86
help
Advanced Configuration and Power Interface (ACPI) support for
Linux requires an ACPI-compliant platform (hardware/firmware),
and assumes the presence of OS-directed configuration and power
management (OSPM) software. This option will enlarge your
kernel by about 70K.
Linux ACPI provides a robust functional replacement for several
legacy configuration and power management interfaces, including
the Plug-and-Play BIOS specification (PnP BIOS), the
MultiProcessor Specification (MPS), and the Advanced Power
Management (APM) specification. If both ACPI and APM support
are configured, ACPI is used.
Linux support for ACPI is based on Intel Corporation's ACPI
Component Architecture (ACPI CA). For more information on the
ACPI CA, see:
<https://acpica.org/>
ACPI is an open industry specification originally co-developed by
Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. Currently,
it is developed by the ACPI Specification Working Group (ASWG) under
the UEFI Forum and any UEFI member can join the ASWG and contribute
to the ACPI specification.
The specification is available at:
<https://uefi.org/specifications>
if ACPI
config ACPI_LEGACY_TABLES_LOOKUP
bool
config ARCH_MIGHT_HAVE_ACPI_PDC
bool
config ACPI_GENERIC_GSI
bool
config ACPI_SYSTEM_POWER_STATES_SUPPORT
bool
config ACPI_CCA_REQUIRED
bool
config ACPI_TABLE_LIB
bool
config ACPI_DEBUGGER
bool "AML debugger interface"
select ACPI_DEBUG
help
Enable in-kernel debugging of AML facilities: statistics,
internal object dump, single step control method execution.
This is still under development, currently enabling this only
results in the compilation of the ACPICA debugger files.
if ACPI_DEBUGGER
config ACPI_DEBUGGER_USER
tristate "Userspace debugger accessibility"
depends on DEBUG_FS
help
Export /sys/kernel/debug/acpi/acpidbg for userspace utilities
to access the debugger functionalities.
endif
config ACPI_SPCR_TABLE
bool "ACPI Serial Port Console Redirection Support"
default y if X86
help
Enable support for Serial Port Console Redirection (SPCR) Table.
This table provides information about the configuration of the
earlycon console.
config ACPI_FPDT
bool "ACPI Firmware Performance Data Table (FPDT) support"
depends on X86_64 || ARM64
help
Enable support for the Firmware Performance Data Table (FPDT).
This table provides information on the timing of the system
boot, S3 suspend and S3 resume firmware code paths.
config ACPI_LPIT
bool
depends on X86_64
default y
config ACPI_SLEEP
bool
depends on SUSPEND || HIBERNATION
depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
default y
config ACPI_REV_OVERRIDE_POSSIBLE
bool "Allow supported ACPI revision to be overridden"
depends on X86
default y
help
The platform firmware on some systems expects Linux to return "5" as
the supported ACPI revision which makes it expose system configuration
information in a special way.
For example, based on what ACPI exports as the supported revision,
Dell XPS 13 (2015) configures its audio device to either work in HDA
mode or in I2S mode, where the former is supposed to be used on Linux
until the latter is fully supported (in the kernel as well as in user
space).
This option enables a DMI-based quirk for the above Dell machine (so
that HDA audio is exposed by the platform firmware to the kernel) and
makes it possible to force the kernel to return "5" as the supported
ACPI revision via the "acpi_rev_override" command line switch.
config ACPI_EC_DEBUGFS
tristate "EC read/write access through /sys/kernel/debug/ec"
help
Say N to disable Embedded Controller /sys/kernel/debug interface
Be aware that using this interface can confuse your Embedded
Controller in a way that a normal reboot is not enough. You then
have to power off your system, and remove the laptop battery for
some seconds.
An Embedded Controller typically is available on laptops and reads
sensor values like battery state and temperature.
The kernel accesses the EC through ACPI parsed code provided by BIOS
tables. This option allows to access the EC directly without ACPI
code being involved.
Thus this option is a debug option that helps to write ACPI drivers
and can be used to identify ACPI code or EC firmware bugs.
config ACPI_AC
tristate "AC Adapter"
select POWER_SUPPLY
default y
help
This driver supports the AC Adapter object, which indicates
whether a system is on AC or not. If you have a system that can
switch between A/C and battery, say Y.
To compile this driver as a module, choose M here:
the module will be called ac.
config ACPI_BATTERY
tristate "Battery"
select POWER_SUPPLY
default y
help
This driver adds support for battery information through
/proc/acpi/battery. If you have a mobile system with a battery,
say Y.
To compile this driver as a module, choose M here:
the module will be called battery.
config ACPI_BUTTON
tristate "Button"
depends on INPUT
default y
help
This driver handles events on the power, sleep, and lid buttons.
A daemon reads events from input devices or via netlink and
performs user-defined actions such as shutting down the system.
This is necessary for software-controlled poweroff.
To compile this driver as a module, choose M here:
the module will be called button.
config ACPI_TINY_POWER_BUTTON
tristate "Tiny Power Button Driver"
depends on !ACPI_BUTTON
help
This driver provides a tiny alternative to the ACPI Button driver.
The tiny power button driver only handles the power button. Rather
than notifying userspace via the input layer or a netlink event, this
driver directly signals the init process to shut down.
This driver is particularly suitable for cloud and VM environments,
which use a simulated power button to initiate a controlled poweroff,
but which may not want to run a separate userspace daemon to process
input events.
config ACPI_TINY_POWER_BUTTON_SIGNAL
int "Tiny Power Button Signal"
depends on ACPI_TINY_POWER_BUTTON
default 38
help
Default signal to send to init in response to the power button.
Likely values here include 38 (SIGRTMIN+4) to power off, or 2
(SIGINT) to simulate Ctrl+Alt+Del.
config ACPI_VIDEO
tristate "Video"
depends on BACKLIGHT_CLASS_DEVICE
depends on INPUT
depends on ACPI_WMI || !X86
select THERMAL
help
This driver implements the ACPI Extensions For Display Adapters
for integrated graphics devices on motherboard, as specified in
ACPI 2.0 Specification, Appendix B. This supports basic operations
such as defining the video POST device, retrieving EDID information,
and setting up a video output.
To compile this driver as a module, choose M here:
the module will be called video.
config ACPI_FAN
tristate "Fan"
depends on THERMAL
default y
help
This driver supports ACPI fan devices, allowing user-mode
applications to perform basic fan control (on, off, status).
To compile this driver as a module, choose M here:
the module will be called fan.
config ACPI_TAD
tristate "ACPI Time and Alarm (TAD) Device Support"
depends on SYSFS && PM_SLEEP
help
The ACPI Time and Alarm (TAD) device is an alternative to the Real
Time Clock (RTC). Its wake timers allow the system to transition from
the S3 (or optionally S4/S5) state to S0 state after a time period
elapses. In comparison with the RTC Alarm, the TAD provides a larger
scale of flexibility in the wake timers. The time capabilities of the
TAD maintain the time of day information across platform power
transitions, and keep track of time even when the platform is turned
off.
config ACPI_DOCK
bool "Dock"
help
This driver supports ACPI-controlled docking stations and removable
drive bays such as the IBM Ultrabay and the Dell Module Bay.
config ACPI_CPU_FREQ_PSS
bool
config ACPI_PROCESSOR_CSTATE
def_bool y
depends on ACPI_PROCESSOR
depends on IA64 || X86
config ACPI_PROCESSOR_IDLE
bool
select CPU_IDLE
config ACPI_MCFG
bool
config ACPI_CPPC_LIB
bool
depends on ACPI_PROCESSOR
select MAILBOX
select PCC
help
If this option is enabled, this file implements common functionality
to parse CPPC tables as described in the ACPI 5.1+ spec. The
routines implemented are meant to be used by other
drivers to control CPU performance using CPPC semantics.
If your platform does not support CPPC in firmware,
leave this option disabled.
config ACPI_PROCESSOR
tristate "Processor"
depends on X86 || IA64 || ARM64 || LOONGARCH
select ACPI_PROCESSOR_IDLE
select ACPI_CPU_FREQ_PSS if X86 || IA64 || LOONGARCH
select THERMAL
default y
help
This driver adds support for the ACPI Processor package. It is required
by several flavors of cpufreq performance-state, thermal, throttling and
idle drivers.
To compile this driver as a module, choose M here:
the module will be called processor.
config ACPI_IPMI
tristate "IPMI"
depends on IPMI_HANDLER
help
This driver enables the ACPI to access the BMC controller. And it
uses the IPMI request/response message to communicate with BMC
controller, which can be found on the server.
To compile this driver as a module, choose M here:
the module will be called as acpi_ipmi.
config ACPI_HOTPLUG_CPU
bool
depends on ACPI_PROCESSOR && HOTPLUG_CPU
select ACPI_CONTAINER
default y
config ACPI_PROCESSOR_AGGREGATOR
tristate "Processor Aggregator"
depends on ACPI_PROCESSOR
depends on X86
help
ACPI 4.0 defines processor Aggregator, which enables OS to perform
specific processor configuration and control that applies to all
processors in the platform. Currently only logical processor idling
is defined, which is to reduce power consumption. This driver
supports the new device.
config ACPI_THERMAL
tristate "Thermal Zone"
depends on ACPI_PROCESSOR
select THERMAL
default y
help
This driver supports ACPI thermal zones. Most mobile and
some desktop systems support ACPI thermal zones. It is HIGHLY
recommended that this option be enabled, as your processor(s)
may be damaged without it.
To compile this driver as a module, choose M here:
the module will be called thermal.
config ACPI_PLATFORM_PROFILE
tristate
config ACPI_CUSTOM_DSDT_FILE
string "Custom DSDT Table file to include"
default ""
depends on !STANDALONE
help
This option supports a custom DSDT by linking it into the kernel.
Enter the full path name to the file which includes the AmlCode
or dsdt_aml_code declaration.
If unsure, don't enter a file name.
config ACPI_CUSTOM_DSDT
bool
default ACPI_CUSTOM_DSDT_FILE != ""
config ARCH_HAS_ACPI_TABLE_UPGRADE
def_bool n
config ACPI_TABLE_UPGRADE
bool "Allow upgrading ACPI tables via initrd"
depends on BLK_DEV_INITRD && ARCH_HAS_ACPI_TABLE_UPGRADE
default y
help
This option provides functionality to upgrade arbitrary ACPI tables
via initrd. No functional change if no ACPI tables are passed via
initrd, therefore it's safe to say Y.
See Documentation/admin-guide/acpi/initrd_table_override.rst for details
config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
bool "Override ACPI tables from built-in initrd"
depends on ACPI_TABLE_UPGRADE
depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION_NONE
help
This option provides functionality to override arbitrary ACPI tables
from built-in uncompressed initrd.
See Documentation/admin-guide/acpi/initrd_table_override.rst for details
config ACPI_DEBUG
bool "Debug Statements"
help
The ACPI subsystem can produce debug output. Saying Y enables this
output and increases the kernel size by around 50K.
Use the acpi.debug_layer and acpi.debug_level kernel command-line
parameters documented in Documentation/firmware-guide/acpi/debug.rst and
Documentation/admin-guide/kernel-parameters.rst to control the type and
amount of debug output.
config ACPI_PCI_SLOT
bool "PCI slot detection driver"
depends on SYSFS && PCI
help
This driver creates entries in /sys/bus/pci/slots/ for all PCI
slots in the system. This can help correlate PCI bus addresses,
i.e., segment/bus/device/function tuples, with physical slots in
the system. If you are unsure, say N.
config ACPI_CONTAINER
bool "Container and Module Devices"
default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU)
help
This driver supports ACPI Container and Module devices (IDs
ACPI0004, PNP0A05, and PNP0A06).
This helps support hotplug of nodes, CPUs, and memory.
config ACPI_HOTPLUG_MEMORY
bool "Memory Hotplug"
depends on MEMORY_HOTPLUG
help
This driver supports ACPI memory hotplug. The driver
fields notifications on ACPI memory devices (PNP0C80),
which represent memory ranges that may be onlined or
offlined during runtime.
If your hardware and firmware do not support adding or
removing memory devices at runtime, you need not enable
this driver.
config ACPI_HOTPLUG_IOAPIC
bool
depends on PCI
depends on X86_IO_APIC
default y
config ACPI_SBS
tristate "Smart Battery System"
depends on X86
select POWER_SUPPLY
help
This driver supports the Smart Battery System, another
type of access to battery information, found on some laptops.
To compile this driver as a module, choose M here:
the modules will be called sbs and sbshc.
config ACPI_HED
tristate "Hardware Error Device"
help
This driver supports the Hardware Error Device (PNP0C33),
which is used to report some hardware errors notified via
SCI, mainly the corrected errors.
config ACPI_CUSTOM_METHOD
tristate "Allow ACPI methods to be inserted/replaced at run time"
depends on DEBUG_FS
help
This debug facility allows ACPI AML methods to be inserted and/or
replaced without rebooting the system. For details refer to:
Documentation/firmware-guide/acpi/method-customizing.rst.
NOTE: This option is security sensitive, because it allows arbitrary
kernel memory to be written to by root (uid=0) users, allowing them
to bypass certain security measures (e.g. if root is not allowed to
load additional kernel modules after boot, this feature may be used
to override that restriction).
config ACPI_BGRT
bool "Boottime Graphics Resource Table support"
depends on EFI && (X86 || ARM64)
help
This driver adds support for exposing the ACPI Boottime Graphics
Resource Table, which allows the operating system to obtain
data from the firmware boot splash. It will appear under
/sys/firmware/acpi/bgrt/ .
config ACPI_REDUCED_HARDWARE_ONLY
bool "Hardware-reduced ACPI support only" if EXPERT
def_bool n
help
This config item changes the way the ACPI code is built. When this
option is selected, the kernel will use a specialized version of
ACPICA that ONLY supports the ACPI "reduced hardware" mode. The
resulting kernel will be smaller but it will also be restricted to
running in ACPI reduced hardware mode ONLY.
If you are unsure what to do, do not enable this option.
source "drivers/acpi/nfit/Kconfig"
source "drivers/acpi/numa/Kconfig"
source "drivers/acpi/apei/Kconfig"
source "drivers/acpi/dptf/Kconfig"
config ACPI_WATCHDOG
bool
config ACPI_EXTLOG
tristate "Extended Error Log support"
depends on X86_MCE && X86_LOCAL_APIC && EDAC
select UEFI_CPER
help
Certain usages such as Predictive Failure Analysis (PFA) require
more information about the error than what can be described in
processor machine check banks. Most server processors log
additional information about the error in processor uncore
registers. Since the addresses and layout of these registers vary
widely from one processor to another, system software cannot
readily make use of them. To complicate matters further, some of
the additional error information cannot be constructed without
detailed knowledge about platform topology.
Enhanced MCA Logging allows firmware to provide additional error
information to system software, synchronous with MCE or CMCI. This
driver adds support for that functionality with corresponding
tracepoint which carries that information to userspace.
config ACPI_ADXL
bool
config ACPI_CONFIGFS
tristate "ACPI configfs support"
select CONFIGFS_FS
help
Select this option to enable support for ACPI configuration from
userspace. The configurable ACPI groups will be visible under
/config/acpi, assuming configfs is mounted under /config.
config ACPI_PFRUT
tristate "ACPI Platform Firmware Runtime Update and Telemetry"
depends on 64BIT
help
This mechanism allows certain pieces of the platform firmware
to be updated on the fly while the system is running (runtime)
without the need to restart it, which is key in the cases when
the system needs to be available 100% of the time and it cannot
afford the downtime related to restarting it, or when the work
carried out by the system is particularly important, so it cannot
be interrupted, and it is not practical to wait until it is complete.
The existing firmware code can be modified (driver update) or
extended by adding new code to the firmware (code injection).
Besides, the telemetry driver allows user space to fetch telemetry
data from the firmware with the help of the Platform Firmware Runtime
Telemetry interface.
To compile the drivers as modules, choose M here:
the modules will be called pfr_update and pfr_telemetry.
if ARM64
source "drivers/acpi/arm64/Kconfig"
config ACPI_PPTT
bool
endif
config ACPI_PCC
bool "ACPI PCC Address Space"
depends on PCC
default y
help
The PCC Address Space also referred as PCC Operation Region pertains
to the region of PCC subspace that succeeds the PCC signature.
The PCC Operation Region works in conjunction with the PCC Table
(Platform Communications Channel Table). PCC subspaces that are
marked for use as PCC Operation Regions must not be used as PCC
subspaces for the standard ACPI features such as CPPC, RASF, PDTT and
MPST. These standard features must always use the PCC Table instead.
Enable this feature if you want to set up and install the PCC Address
Space handler to handle PCC OpRegion in the firmware.
config ACPI_FFH
bool "ACPI FFH Address Space"
default n
help
The FFH(Fixed Function Hardware) Address Space also referred as FFH
Operation Region allows to define platform specific opregion.
Enable this feature if you want to set up and install the FFH Address
Space handler to handle FFH OpRegion in the firmware.
source "drivers/acpi/pmic/Kconfig"
config ACPI_VIOT
bool
config ACPI_PRMT
bool "Platform Runtime Mechanism Support"
depends on EFI && (X86_64 || ARM64)
default y
help
Platform Runtime Mechanism (PRM) is a firmware interface exposing a
set of binary executables that can be called from the AML interpreter
or directly from device drivers.
Say Y to enable the AML interpreter to execute the PRM code.
While this feature is optional in principle, leaving it out may
substantially increase computational overhead related to the
initialization of some server systems.
endif # ACPI
config X86_PM_TIMER
bool "Power Management Timer Support" if EXPERT
depends on X86 && (ACPI || JAILHOUSE_GUEST)
default y
help
The Power Management Timer is available on all ACPI-capable,
in most cases even if ACPI is unusable or blacklisted.
This timing source is not affected by power management features
like aggressive processor idling, throttling, frequency and/or
voltage scaling, unlike the commonly used Time Stamp Counter
(TSC) timing source.
You should nearly always say Y here because many modern
systems require this timer.
