diff options
Diffstat (limited to 'Documentation/admin-guide/acpi')
| -rw-r--r-- | Documentation/admin-guide/acpi/cppc_sysfs.rst | 6 | ||||
| -rw-r--r-- | Documentation/admin-guide/acpi/dsdt-override.rst | 13 | ||||
| -rw-r--r-- | Documentation/admin-guide/acpi/fan_performance_states.rst | 28 | ||||
| -rw-r--r-- | Documentation/admin-guide/acpi/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/acpi/initrd_table_override.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/acpi/ssdt-overlays.rst | 51 |
6 files changed, 59 insertions, 42 deletions
diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst index a4b99afbe331..e53d76365aa7 100644 --- a/Documentation/admin-guide/acpi/cppc_sysfs.rst +++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst @@ -4,11 +4,13 @@ Collaborative Processor Performance Control (CPPC) ================================================== +.. _cppc_sysfs: + CPPC ==== CPPC defined in the ACPI spec describes a mechanism for the OS to manage the -performance of a logical processor on a contigious and abstract performance +performance of a logical processor on a contiguous and abstract performance scale. CPPC exposes a set of registers to describe abstract performance scale, to request performance levels and to measure per-cpu delivered performance. @@ -45,7 +47,7 @@ for each cpu X:: * lowest_freq : CPU frequency corresponding to lowest_perf (in MHz). * nominal_freq : CPU frequency corresponding to nominal_perf (in MHz). The above frequencies should only be used to report processor performance in - freqency instead of abstract scale. These values should not be used for any + frequency instead of abstract scale. These values should not be used for any functional decisions. * feedback_ctrs : Includes both Reference and delivered performance counter. diff --git a/Documentation/admin-guide/acpi/dsdt-override.rst b/Documentation/admin-guide/acpi/dsdt-override.rst deleted file mode 100644 index 50bd7f194bf4..000000000000 --- a/Documentation/admin-guide/acpi/dsdt-override.rst +++ /dev/null @@ -1,13 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -=============== -Overriding DSDT -=============== - -Linux supports a method of overriding the BIOS DSDT: - -CONFIG_ACPI_CUSTOM_DSDT - builds the image into the kernel. - -When to use this method is described in detail on the -Linux/ACPI home page: -https://01.org/linux-acpi/documentation/overriding-dsdt diff --git a/Documentation/admin-guide/acpi/fan_performance_states.rst b/Documentation/admin-guide/acpi/fan_performance_states.rst index 98fe5c333121..b9e4b4d146c1 100644 --- a/Documentation/admin-guide/acpi/fan_performance_states.rst +++ b/Documentation/admin-guide/acpi/fan_performance_states.rst @@ -60,3 +60,31 @@ For example:: When a given field is not populated or its value provided by the platform firmware is invalid, the "not-defined" string is shown instead of the value. + +ACPI Fan Fine Grain Control +============================= + +When _FIF object specifies support for fine grain control, then fan speed +can be set from 0 to 100% with the recommended minimum "step size" via +_FSL object. User can adjust fan speed using thermal sysfs cooling device. + +Here use can look at fan performance states for a reference speed (speed_rpm) +and set it by changing cooling device cur_state. If the fine grain control +is supported then user can also adjust to some other speeds which are +not defined in the performance states. + +The support of fine grain control is presented via sysfs attribute +"fine_grain_control". If fine grain control is present, this attribute +will show "1" otherwise "0". + +This sysfs attribute is presented in the same directory as performance states. + +ACPI Fan Performance Feedback +============================= + +The optional _FST object provides status information for the fan device. +This includes field to provide current fan speed in revolutions per minute +at which the fan is rotating. + +This speed is presented in the sysfs using the attribute "fan_speed_rpm", +in the same directory as performance states. diff --git a/Documentation/admin-guide/acpi/index.rst b/Documentation/admin-guide/acpi/index.rst index 71277689ad97..b078fdb8f4c9 100644 --- a/Documentation/admin-guide/acpi/index.rst +++ b/Documentation/admin-guide/acpi/index.rst @@ -9,7 +9,6 @@ the Linux ACPI support. :maxdepth: 1 initrd_table_override - dsdt-override ssdt-overlays cppc_sysfs fan_performance_states diff --git a/Documentation/admin-guide/acpi/initrd_table_override.rst b/Documentation/admin-guide/acpi/initrd_table_override.rst index cbd768207631..bb24fa6b5fbe 100644 --- a/Documentation/admin-guide/acpi/initrd_table_override.rst +++ b/Documentation/admin-guide/acpi/initrd_table_override.rst @@ -102,7 +102,7 @@ Where to retrieve userspace tools ================================= iasl and acpixtract are part of Intel's ACPICA project: -http://acpica.org/ +https://acpica.org/ and should be packaged by distributions (for example in the acpica package on SUSE). diff --git a/Documentation/admin-guide/acpi/ssdt-overlays.rst b/Documentation/admin-guide/acpi/ssdt-overlays.rst index da37455f96c9..b5fbf54dca19 100644 --- a/Documentation/admin-guide/acpi/ssdt-overlays.rst +++ b/Documentation/admin-guide/acpi/ssdt-overlays.rst @@ -30,22 +30,21 @@ following ASL code can be used:: { Device (STAC) { - Name (_ADR, Zero) Name (_HID, "BMA222E") + Name (RBUF, ResourceTemplate () + { + I2cSerialBus (0x0018, ControllerInitiated, 0x00061A80, + AddressingMode7Bit, "\\_SB.I2C6", 0x00, + ResourceConsumer, ,) + GpioInt (Edge, ActiveHigh, Exclusive, PullDown, 0x0000, + "\\_SB.GPO2", 0x00, ResourceConsumer, , ) + { // Pin list + 0 + } + }) Method (_CRS, 0, Serialized) { - Name (RBUF, ResourceTemplate () - { - I2cSerialBus (0x0018, ControllerInitiated, 0x00061A80, - AddressingMode7Bit, "\\_SB.I2C6", 0x00, - ResourceConsumer, ,) - GpioInt (Edge, ActiveHigh, Exclusive, PullDown, 0x0000, - "\\_SB.GPO2", 0x00, ResourceConsumer, , ) - { // Pin list - 0 - } - }) Return (RBUF) } } @@ -63,7 +62,7 @@ which can then be compiled to AML binary format:: ASL Input: minnomax.asl - 30 lines, 614 bytes, 7 keywords AML Output: minnowmax.aml - 165 bytes, 6 named objects, 1 executable opcodes -[1] http://wiki.minnowboard.org/MinnowBoard_MAX#Low_Speed_Expansion_Connector_.28Top.29 +[1] https://www.elinux.org/Minnowboard:MinnowMax#Low_Speed_Expansion_.28Top.29 The resulting AML code can then be loaded by the kernel using one of the methods below. @@ -75,7 +74,7 @@ This option allows loading of user defined SSDTs from initrd and it is useful when the system does not support EFI or when there is not enough EFI storage. It works in a similar way with initrd based ACPI tables override/upgrade: SSDT -aml code must be placed in the first, uncompressed, initrd under the +AML code must be placed in the first, uncompressed, initrd under the "kernel/firmware/acpi" path. Multiple files can be used and this will translate in loading multiple tables. Only SSDT and OEM tables are allowed. See initrd_table_override.txt for more details. @@ -103,12 +102,14 @@ This is the preferred method, when EFI is supported on the platform, because it allows a persistent, OS independent way of storing the user defined SSDTs. There is also work underway to implement EFI support for loading user defined SSDTs and using this method will make it easier to convert to the EFI loading -mechanism when that will arrive. +mechanism when that will arrive. To enable it, the +CONFIG_EFI_CUSTOM_SSDT_OVERLAYS shoyld be chosen to y. -In order to load SSDTs from an EFI variable the efivar_ssdt kernel command line -parameter can be used. The argument for the option is the variable name to -use. If there are multiple variables with the same name but with different -vendor GUIDs, all of them will be loaded. +In order to load SSDTs from an EFI variable the ``"efivar_ssdt=..."`` kernel +command line parameter can be used (the name has a limitation of 16 characters). +The argument for the option is the variable name to use. If there are multiple +variables with the same name but with different vendor GUIDs, all of them will +be loaded. In order to store the AML code in an EFI variable the efivarfs filesystem can be used. It is enabled and mounted by default in /sys/firmware/efi/efivars in all @@ -127,7 +128,7 @@ variable with the content from a given file:: #!/bin/sh -e - while ! [ -z "$1" ]; do + while [ -n "$1" ]; do case "$1" in "-f") filename="$2"; shift;; "-g") guid="$2"; shift;; @@ -167,14 +168,14 @@ variable with the content from a given file:: Loading ACPI SSDTs from configfs ================================ -This option allows loading of user defined SSDTs from userspace via the configfs +This option allows loading of user defined SSDTs from user space via the configfs interface. The CONFIG_ACPI_CONFIGFS option must be select and configfs must be mounted. In the following examples, we assume that configfs has been mounted in -/config. +/sys/kernel/config. -New tables can be loading by creating new directories in /config/acpi/table/ and -writing the SSDT aml code in the aml attribute:: +New tables can be loading by creating new directories in /sys/kernel/config/acpi/table +and writing the SSDT AML code in the aml attribute:: - cd /config/acpi/table + cd /sys/kernel/config/acpi/table mkdir my_ssdt cat ~/ssdt.aml > my_ssdt/aml |