# 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 select FIRMWARE_TABLE 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: 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: 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_THERMAL_LIB depends on THERMAL 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 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 || ARM64 || LOONGARCH select ACPI_PROCESSOR_IDLE select ACPI_CPU_FREQ_PSS if X86 || 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 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 select ACPI_THERMAL_LIB 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" endif config ACPI_PPTT bool 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_RUNTIME_WRAPPERS && (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.