1 # SPDX-License-Identifier: GPL-2.0
6 config ARCH_SUPPORTS_ACPI
10 bool "ACPI (Advanced Configuration and Power Interface) Support"
11 depends on ARCH_SUPPORTS_ACPI
16 Advanced Configuration and Power Interface (ACPI) support for
17 Linux requires an ACPI-compliant platform (hardware/firmware),
18 and assumes the presence of OS-directed configuration and power
19 management (OSPM) software. This option will enlarge your
22 Linux ACPI provides a robust functional replacement for several
23 legacy configuration and power management interfaces, including
24 the Plug-and-Play BIOS specification (PnP BIOS), the
25 MultiProcessor Specification (MPS), and the Advanced Power
26 Management (APM) specification. If both ACPI and APM support
27 are configured, ACPI is used.
29 The project home page for the Linux ACPI subsystem is here:
30 <https://01.org/linux-acpi>
32 Linux support for ACPI is based on Intel Corporation's ACPI
33 Component Architecture (ACPI CA). For more information on the
37 ACPI is an open industry specification originally co-developed by
38 Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. Currently,
39 it is developed by the ACPI Specification Working Group (ASWG) under
40 the UEFI Forum and any UEFI member can join the ASWG and contribute
41 to the ACPI specification.
42 The specification is available at:
43 <https://uefi.org/specifications>
47 config ACPI_LEGACY_TABLES_LOOKUP
50 config ARCH_MIGHT_HAVE_ACPI_PDC
53 config ACPI_GENERIC_GSI
56 config ACPI_SYSTEM_POWER_STATES_SUPPORT
59 config ACPI_CCA_REQUIRED
63 bool "AML debugger interface"
66 Enable in-kernel debugging of AML facilities: statistics,
67 internal object dump, single step control method execution.
68 This is still under development, currently enabling this only
69 results in the compilation of the ACPICA debugger files.
73 config ACPI_DEBUGGER_USER
74 tristate "Userspace debugger accessiblity"
77 Export /sys/kernel/debug/acpi/acpidbg for userspace utilities
78 to access the debugger functionalities.
82 config ACPI_SPCR_TABLE
83 bool "ACPI Serial Port Console Redirection Support"
86 Enable support for Serial Port Console Redirection (SPCR) Table.
87 This table provides information about the configuration of the
97 depends on SUSPEND || HIBERNATION
98 depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
101 config ACPI_REV_OVERRIDE_POSSIBLE
102 bool "Allow supported ACPI revision to be overridden"
106 The platform firmware on some systems expects Linux to return "5" as
107 the supported ACPI revision which makes it expose system configuration
108 information in a special way.
110 For example, based on what ACPI exports as the supported revision,
111 Dell XPS 13 (2015) configures its audio device to either work in HDA
112 mode or in I2S mode, where the former is supposed to be used on Linux
113 until the latter is fully supported (in the kernel as well as in user
116 This option enables a DMI-based quirk for the above Dell machine (so
117 that HDA audio is exposed by the platform firmware to the kernel) and
118 makes it possible to force the kernel to return "5" as the supported
119 ACPI revision via the "acpi_rev_override" command line switch.
121 config ACPI_EC_DEBUGFS
122 tristate "EC read/write access through /sys/kernel/debug/ec"
124 Say N to disable Embedded Controller /sys/kernel/debug interface
126 Be aware that using this interface can confuse your Embedded
127 Controller in a way that a normal reboot is not enough. You then
128 have to power off your system, and remove the laptop battery for
130 An Embedded Controller typically is available on laptops and reads
131 sensor values like battery state and temperature.
132 The kernel accesses the EC through ACPI parsed code provided by BIOS
133 tables. This option allows to access the EC directly without ACPI
135 Thus this option is a debug option that helps to write ACPI drivers
136 and can be used to identify ACPI code or EC firmware bugs.
139 tristate "AC Adapter"
143 This driver supports the AC Adapter object, which indicates
144 whether a system is on AC or not. If you have a system that can
145 switch between A/C and battery, say Y.
147 To compile this driver as a module, choose M here:
148 the module will be called ac.
155 This driver adds support for battery information through
156 /proc/acpi/battery. If you have a mobile system with a battery,
159 To compile this driver as a module, choose M here:
160 the module will be called battery.
167 This driver handles events on the power, sleep, and lid buttons.
168 A daemon reads events from input devices or via netlink and
169 performs user-defined actions such as shutting down the system.
170 This is necessary for software-controlled poweroff.
172 To compile this driver as a module, choose M here:
173 the module will be called button.
175 config ACPI_TINY_POWER_BUTTON
176 tristate "Tiny Power Button Driver"
177 depends on !ACPI_BUTTON
179 This driver provides a tiny alternative to the ACPI Button driver.
180 The tiny power button driver only handles the power button. Rather
181 than notifying userspace via the input layer or a netlink event, this
182 driver directly signals the init process to shut down.
184 This driver is particularly suitable for cloud and VM environments,
185 which use a simulated power button to initiate a controlled poweroff,
186 but which may not want to run a separate userspace daemon to process
189 config ACPI_TINY_POWER_BUTTON_SIGNAL
190 int "Tiny Power Button Signal"
191 depends on ACPI_TINY_POWER_BUTTON
194 Default signal to send to init in response to the power button.
196 Likely values here include 38 (SIGRTMIN+4) to power off, or 2
197 (SIGINT) to simulate Ctrl+Alt+Del.
201 depends on X86 && BACKLIGHT_CLASS_DEVICE
205 This driver implements the ACPI Extensions For Display Adapters
206 for integrated graphics devices on motherboard, as specified in
207 ACPI 2.0 Specification, Appendix B. This supports basic operations
208 such as defining the video POST device, retrieving EDID information,
209 and setting up a video output.
211 To compile this driver as a module, choose M here:
212 the module will be called video.
219 This driver supports ACPI fan devices, allowing user-mode
220 applications to perform basic fan control (on, off, status).
222 To compile this driver as a module, choose M here:
223 the module will be called fan.
226 tristate "ACPI Time and Alarm (TAD) Device Support"
227 depends on SYSFS && PM_SLEEP
229 The ACPI Time and Alarm (TAD) device is an alternative to the Real
230 Time Clock (RTC). Its wake timers allow the system to transition from
231 the S3 (or optionally S4/S5) state to S0 state after a time period
232 elapses. In comparison with the RTC Alarm, the TAD provides a larger
233 scale of flexibility in the wake timers. The time capabilities of the
234 TAD maintain the time of day information across platform power
235 transitions, and keep track of time even when the platform is turned
241 This driver supports ACPI-controlled docking stations and removable
242 drive bays such as the IBM Ultrabay and the Dell Module Bay.
244 config ACPI_CPU_FREQ_PSS
248 config ACPI_PROCESSOR_CSTATE
250 depends on ACPI_PROCESSOR
251 depends on IA64 || X86
253 config ACPI_PROCESSOR_IDLE
262 depends on ACPI_PROCESSOR
266 If this option is enabled, this file implements common functionality
267 to parse CPPC tables as described in the ACPI 5.1+ spec. The
268 routines implemented are meant to be used by other
269 drivers to control CPU performance using CPPC semantics.
270 If your platform does not support CPPC in firmware,
271 leave this option disabled.
273 config ACPI_PROCESSOR
275 depends on X86 || IA64 || ARM64
276 select ACPI_PROCESSOR_IDLE
277 select ACPI_CPU_FREQ_PSS if X86 || IA64
280 This driver adds support for the ACPI Processor package. It is required
281 by several flavors of cpufreq performance-state, thermal, throttling and
284 To compile this driver as a module, choose M here:
285 the module will be called processor.
289 depends on IPMI_HANDLER
291 This driver enables the ACPI to access the BMC controller. And it
292 uses the IPMI request/response message to communicate with BMC
293 controller, which can be found on on the server.
295 To compile this driver as a module, choose M here:
296 the module will be called as acpi_ipmi.
298 config ACPI_HOTPLUG_CPU
300 depends on ACPI_PROCESSOR && HOTPLUG_CPU
301 select ACPI_CONTAINER
304 config ACPI_PROCESSOR_AGGREGATOR
305 tristate "Processor Aggregator"
306 depends on ACPI_PROCESSOR
309 ACPI 4.0 defines processor Aggregator, which enables OS to perform
310 specific processor configuration and control that applies to all
311 processors in the platform. Currently only logical processor idling
312 is defined, which is to reduce power consumption. This driver
313 supports the new device.
316 tristate "Thermal Zone"
317 depends on ACPI_PROCESSOR
321 This driver supports ACPI thermal zones. Most mobile and
322 some desktop systems support ACPI thermal zones. It is HIGHLY
323 recommended that this option be enabled, as your processor(s)
324 may be damaged without it.
326 To compile this driver as a module, choose M here:
327 the module will be called thermal.
329 config ACPI_CUSTOM_DSDT_FILE
330 string "Custom DSDT Table file to include"
332 depends on !STANDALONE
334 This option supports a custom DSDT by linking it into the kernel.
335 See Documentation/admin-guide/acpi/dsdt-override.rst
337 Enter the full path name to the file which includes the AmlCode
338 or dsdt_aml_code declaration.
340 If unsure, don't enter a file name.
342 config ACPI_CUSTOM_DSDT
344 default ACPI_CUSTOM_DSDT_FILE != ""
346 config ARCH_HAS_ACPI_TABLE_UPGRADE
349 config ACPI_TABLE_UPGRADE
350 bool "Allow upgrading ACPI tables via initrd"
351 depends on BLK_DEV_INITRD && ARCH_HAS_ACPI_TABLE_UPGRADE
354 This option provides functionality to upgrade arbitrary ACPI tables
355 via initrd. No functional change if no ACPI tables are passed via
356 initrd, therefore it's safe to say Y.
357 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
359 config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
360 bool "Override ACPI tables from built-in initrd"
361 depends on ACPI_TABLE_UPGRADE
362 depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION=""
364 This option provides functionality to override arbitrary ACPI tables
365 from built-in uncompressed initrd.
367 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
370 bool "Debug Statements"
372 The ACPI subsystem can produce debug output. Saying Y enables this
373 output and increases the kernel size by around 50K.
375 Use the acpi.debug_layer and acpi.debug_level kernel command-line
376 parameters documented in Documentation/firmware-guide/acpi/debug.rst and
377 Documentation/admin-guide/kernel-parameters.rst to control the type and
378 amount of debug output.
381 bool "PCI slot detection driver"
382 depends on SYSFS && PCI
384 This driver creates entries in /sys/bus/pci/slots/ for all PCI
385 slots in the system. This can help correlate PCI bus addresses,
386 i.e., segment/bus/device/function tuples, with physical slots in
387 the system. If you are unsure, say N.
389 config ACPI_CONTAINER
390 bool "Container and Module Devices"
391 default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU)
393 This driver supports ACPI Container and Module devices (IDs
394 ACPI0004, PNP0A05, and PNP0A06).
396 This helps support hotplug of nodes, CPUs, and memory.
398 To compile this driver as a module, choose M here:
399 the module will be called container.
401 config ACPI_HOTPLUG_MEMORY
402 bool "Memory Hotplug"
403 depends on MEMORY_HOTPLUG
405 This driver supports ACPI memory hotplug. The driver
406 fields notifications on ACPI memory devices (PNP0C80),
407 which represent memory ranges that may be onlined or
408 offlined during runtime.
410 If your hardware and firmware do not support adding or
411 removing memory devices at runtime, you need not enable
414 To compile this driver as a module, choose M here:
415 the module will be called acpi_memhotplug.
417 config ACPI_HOTPLUG_IOAPIC
420 depends on X86_IO_APIC
424 tristate "Smart Battery System"
428 This driver supports the Smart Battery System, another
429 type of access to battery information, found on some laptops.
431 To compile this driver as a module, choose M here:
432 the modules will be called sbs and sbshc.
435 tristate "Hardware Error Device"
437 This driver supports the Hardware Error Device (PNP0C33),
438 which is used to report some hardware errors notified via
439 SCI, mainly the corrected errors.
441 config ACPI_CUSTOM_METHOD
442 tristate "Allow ACPI methods to be inserted/replaced at run time"
445 This debug facility allows ACPI AML methods to be inserted and/or
446 replaced without rebooting the system. For details refer to:
447 Documentation/firmware-guide/acpi/method-customizing.rst.
449 NOTE: This option is security sensitive, because it allows arbitrary
450 kernel memory to be written to by root (uid=0) users, allowing them
451 to bypass certain security measures (e.g. if root is not allowed to
452 load additional kernel modules after boot, this feature may be used
453 to override that restriction).
456 bool "Boottime Graphics Resource Table support"
457 depends on EFI && (X86 || ARM64)
459 This driver adds support for exposing the ACPI Boottime Graphics
460 Resource Table, which allows the operating system to obtain
461 data from the firmware boot splash. It will appear under
462 /sys/firmware/acpi/bgrt/ .
464 config ACPI_REDUCED_HARDWARE_ONLY
465 bool "Hardware-reduced ACPI support only" if EXPERT
468 This config item changes the way the ACPI code is built. When this
469 option is selected, the kernel will use a specialized version of
470 ACPICA that ONLY supports the ACPI "reduced hardware" mode. The
471 resulting kernel will be smaller but it will also be restricted to
472 running in ACPI reduced hardware mode ONLY.
474 If you are unsure what to do, do not enable this option.
476 source "drivers/acpi/nfit/Kconfig"
477 source "drivers/acpi/numa/Kconfig"
478 source "drivers/acpi/apei/Kconfig"
479 source "drivers/acpi/dptf/Kconfig"
485 tristate "Extended Error Log support"
486 depends on X86_MCE && X86_LOCAL_APIC && EDAC
489 Certain usages such as Predictive Failure Analysis (PFA) require
490 more information about the error than what can be described in
491 processor machine check banks. Most server processors log
492 additional information about the error in processor uncore
493 registers. Since the addresses and layout of these registers vary
494 widely from one processor to another, system software cannot
495 readily make use of them. To complicate matters further, some of
496 the additional error information cannot be constructed without
497 detailed knowledge about platform topology.
499 Enhanced MCA Logging allows firmware to provide additional error
500 information to system software, synchronous with MCE or CMCI. This
501 driver adds support for that functionality with corresponding
502 tracepoint which carries that information to userspace.
508 tristate "ACPI configfs support"
511 Select this option to enable support for ACPI configuration from
512 userspace. The configurable ACPI groups will be visible under
513 /config/acpi, assuming configfs is mounted under /config.
516 source "drivers/acpi/arm64/Kconfig"
522 source "drivers/acpi/pmic/Kconfig"
527 bool "Power Management Timer Support" if EXPERT
528 depends on X86 && (ACPI || JAILHOUSE_GUEST)
531 The Power Management Timer is available on all ACPI-capable,
532 in most cases even if ACPI is unusable or blacklisted.
534 This timing source is not affected by power management features
535 like aggressive processor idling, throttling, frequency and/or
536 voltage scaling, unlike the commonly used Time Stamp Counter
539 You should nearly always say Y here because many modern
540 systems require this timer.