diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-27 11:23:54 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-01-27 11:23:54 -0800 |
commit | 6d277aca488fdf0a1e67cd14b5a58869f66197c9 (patch) | |
tree | 2ed50bf4bb32092a9a95e7952533cbde98baeb24 /Documentation | |
parent | aae1464f46a2403565f75717438118691d31ccf1 (diff) | |
parent | c102671af085aacf17219e9bdcfccddc6620a866 (diff) | |
download | linux-6d277aca488fdf0a1e67cd14b5a58869f66197c9.tar.bz2 |
Merge tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These add ACPI support to the intel_idle driver along with an admin
guide document for it, add support for CPR (Core Power Reduction) to
the AVS (Adaptive Voltage Scaling) subsystem, add new hardware support
in a few places, add some new sysfs attributes, debugfs files and
tracepoints, fix bugs and clean up a bunch of things all over.
Specifics:
- Update the ACPI processor driver in order to export
acpi_processor_evaluate_cst() to the code outside of it, add ACPI
support to the intel_idle driver based on that and clean up that
driver somewhat (Rafael Wysocki).
- Add an admin guide document for the intel_idle driver (Rafael
Wysocki).
- Clean up cpuidle core and drivers, enable compilation testing for
some of them (Benjamin Gaignard, Krzysztof Kozlowski, Rafael
Wysocki, Yangtao Li).
- Fix reference counting of OPP (operating performance points) table
structures (Viresh Kumar).
- Add support for CPR (Core Power Reduction) to the AVS (Adaptive
Voltage Scaling) subsystem (Niklas Cassel, Colin Ian King,
YueHaibing).
- Add support for TigerLake Mobile and JasperLake to the Intel RAPL
power capping driver (Zhang Rui).
- Update cpufreq drivers:
- Add i.MX8MP support to imx-cpufreq-dt (Anson Huang).
- Fix usage of a macro in loongson2_cpufreq (Alexandre Oliva).
- Fix cpufreq policy reference counting issues in s3c and
brcmstb-avs (chenqiwu).
- Fix ACPI table reference counting issue and HiSilicon quirk
handling in the CPPC driver (Hanjun Guo).
- Clean up spelling mistake in intel_pstate (Harry Pan).
- Convert the kirkwood and tegra186 drivers to using
devm_platform_ioremap_resource() (Yangtao Li).
- Update devfreq core:
- Add 'name' sysfs attribute for devfreq devices (Chanwoo Choi).
- Clean up the handing of transition statistics and allow them to
be reset by writing 0 to the 'trans_stat' devfreq device
attribute in sysfs (Kamil Konieczny).
- Add 'devfreq_summary' to debugfs (Chanwoo Choi).
- Clean up kerneldoc comments and Kconfig indentation (Krzysztof
Kozlowski, Randy Dunlap).
- Update devfreq drivers:
- Add dynamic scaling for the imx8m DDR controller and clean up
imx8m-ddrc (Leonard Crestez, YueHaibing).
- Fix DT node reference counting and nitialization error code path
in rk3399_dmc and add COMPILE_TEST and HAVE_ARM_SMCCC dependency
for it (Chanwoo Choi, Yangtao Li).
- Fix DT node reference counting in rockchip-dfi and make it use
devm_platform_ioremap_resource() (Yangtao Li).
- Fix excessive stack usage in exynos-ppmu (Arnd Bergmann).
- Fix initialization error code paths in exynos-bus (Yangtao Li).
- Clean up exynos-bus and exynos somewhat (Artur Świgoń, Krzysztof
Kozlowski).
- Add tracepoints for tracking usage_count updates unrelated to
status changes in PM-runtime (Michał Mirosław).
- Add sysfs attribute to control the "sync on suspend" behavior
during system-wide suspend (Jonas Meurer).
- Switch system-wide suspend tests over to 64-bit time (Alexandre
Belloni).
- Make wakeup sources statistics in debugfs cover deleted ones which
used to be the case some time ago (zhuguangqing).
- Clean up computations carried out during hibernation, update
messages related to hibernation and fix a spelling mistake in one
of them (Wen Yang, Luigi Semenzato, Colin Ian King).
- Add mailmap entry for maintainer e-mail address that has not been
functional for several years (Rafael Wysocki)"
* tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (83 commits)
cpufreq: loongson2_cpufreq: adjust cpufreq uses of LOONGSON_CHIPCFG
intel_idle: Clean up irtl_2_usec()
intel_idle: Move 3 functions closer to their callers
intel_idle: Annotate initialization code and data structures
intel_idle: Move and clean up intel_idle_cpuidle_devices_uninit()
intel_idle: Rearrange intel_idle_cpuidle_driver_init()
intel_idle: Clean up NULL pointer check in intel_idle_init()
intel_idle: Fold intel_idle_probe() into intel_idle_init()
intel_idle: Eliminate __setup_broadcast_timer()
cpuidle: fix cpuidle_find_deepest_state() kerneldoc warnings
cpuidle: sysfs: fix warnings when compiling with W=1
cpuidle: coupled: fix warnings when compiling with W=1
cpufreq: brcmstb-avs: fix imbalance of cpufreq policy refcount
PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
PM / devfreq: Add debugfs support with devfreq_summary file
Documentation: admin-guide: PM: Add intel_idle document
cpuidle: arm: Enable compile testing for some of drivers
PM-runtime: add tracepoints for usage_count changes
cpufreq: intel_pstate: fix spelling mistake: "Whethet" -> "Whether"
PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-class-devfreq | 18 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 6 | ||||
-rw-r--r-- | Documentation/ABI/testing/sysfs-power | 13 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/cpuidle.rst | 3 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/intel_idle.rst | 246 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/working-state.rst | 1 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml | 72 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/power/avs/qcom,cpr.txt | 130 |
8 files changed, 485 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 01196e19afca..9758eb85ade3 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -7,6 +7,13 @@ Description: The name of devfreq object denoted as ... is same as the name of device using devfreq. +What: /sys/class/devfreq/.../name +Date: November 2019 +Contact: Chanwoo Choi <cw00.choi@samsung.com> +Description: + The /sys/class/devfreq/.../name shows the name of device + of the corresponding devfreq object. + What: /sys/class/devfreq/.../governor Date: September 2011 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> @@ -48,12 +55,15 @@ What: /sys/class/devfreq/.../trans_stat Date: October 2012 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Description: - This ABI shows the statistics of devfreq behavior on a - specific device. It shows the time spent in each state and - the number of transitions between states. + This ABI shows or clears the statistics of devfreq behavior + on a specific device. It shows the time spent in each state + and the number of transitions between states. In order to activate this ABI, the devfreq target device driver should provide the list of available frequencies - with its profile. + with its profile. If need to reset the statistics of devfreq + behavior on a specific device, enter 0(zero) to 'trans_stat' + as following: + echo 0 > /sys/class/devfreq/.../trans_stat What: /sys/class/devfreq/.../userspace/set_freq Date: September 2011 diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index fc20cde63d1e..2e0e3b45d02a 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -196,6 +196,12 @@ Description: does not reflect it. Likewise, if one enables a deep state but a lighter state still is disabled, then this has no effect. +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status +Date: December 2019 +KernelVersion: v5.6 +Contact: Linux power management list <linux-pm@vger.kernel.org> +Description: + (RO) The default status of this state, "enabled" or "disabled". What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency Date: March 2014 diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 6f87b9dd384b..5e6ead29124c 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -407,3 +407,16 @@ Contact: Kalesh Singh <kaleshsingh96@gmail.com> Description: The /sys/power/suspend_stats/last_failed_step file contains the last failed step in the suspend/resume path. + +What: /sys/power/sync_on_suspend +Date: October 2019 +Contact: Jonas Meurer <jonas@freesources.org> +Description: + This file controls whether or not the kernel will sync() + filesystems during system suspend (after freezing user space + and before suspending devices). + + Writing a "1" to this file enables the sync() and writing a "0" + disables it. Reads from the file return the current value. + The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config + flag is unset, or "0" otherwise. diff --git a/Documentation/admin-guide/pm/cpuidle.rst b/Documentation/admin-guide/pm/cpuidle.rst index e70b365dbc60..311cd7cc2b75 100644 --- a/Documentation/admin-guide/pm/cpuidle.rst +++ b/Documentation/admin-guide/pm/cpuidle.rst @@ -506,6 +506,9 @@ object corresponding to it, as follows: ``disable`` Whether or not this idle state is disabled. +``default_status`` + The default status of this state, "enabled" or "disabled". + ``latency`` Exit latency of the idle state in microseconds. diff --git a/Documentation/admin-guide/pm/intel_idle.rst b/Documentation/admin-guide/pm/intel_idle.rst new file mode 100644 index 000000000000..afbf778035f8 --- /dev/null +++ b/Documentation/admin-guide/pm/intel_idle.rst @@ -0,0 +1,246 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: <isonum.txt> + +============================================== +``intel_idle`` CPU Idle Time Management Driver +============================================== + +:Copyright: |copy| 2020 Intel Corporation + +:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> + + +General Information +=================== + +``intel_idle`` is a part of the +:doc:`CPU idle time management subsystem <cpuidle>` in the Linux kernel +(``CPUIdle``). It is the default CPU idle time management driver for the +Nehalem and later generations of Intel processors, but the level of support for +a particular processor model in it depends on whether or not it recognizes that +processor model and may also depend on information coming from the platform +firmware. [To understand ``intel_idle`` it is necessary to know how ``CPUIdle`` +works in general, so this is the time to get familiar with :doc:`cpuidle` if you +have not done that yet.] + +``intel_idle`` uses the ``MWAIT`` instruction to inform the processor that the +logical CPU executing it is idle and so it may be possible to put some of the +processor's functional blocks into low-power states. That instruction takes two +arguments (passed in the ``EAX`` and ``ECX`` registers of the target CPU), the +first of which, referred to as a *hint*, can be used by the processor to +determine what can be done (for details refer to Intel Software Developer’s +Manual [1]_). Accordingly, ``intel_idle`` refuses to work with processors in +which the support for the ``MWAIT`` instruction has been disabled (for example, +via the platform firmware configuration menu) or which do not support that +instruction at all. + +``intel_idle`` is not modular, so it cannot be unloaded, which means that the +only way to pass early-configuration-time parameters to it is via the kernel +command line. + + +.. _intel-idle-enumeration-of-states: + +Enumeration of Idle States +========================== + +Each ``MWAIT`` hint value is interpreted by the processor as a license to +reconfigure itself in a certain way in order to save energy. The processor +configurations (with reduced power draw) resulting from that are referred to +as C-states (in the ACPI terminology) or idle states. The list of meaningful +``MWAIT`` hint values and idle states (i.e. low-power configurations of the +processor) corresponding to them depends on the processor model and it may also +depend on the configuration of the platform. + +In order to create a list of available idle states required by the ``CPUIdle`` +subsystem (see :ref:`idle-states-representation` in :doc:`cpuidle`), +``intel_idle`` can use two sources of information: static tables of idle states +for different processor models included in the driver itself and the ACPI tables +of the system. The former are always used if the processor model at hand is +recognized by ``intel_idle`` and the latter are used if that is required for +the given processor model (which is the case for all server processor models +recognized by ``intel_idle``) or if the processor model is not recognized. + +If the ACPI tables are going to be used for building the list of available idle +states, ``intel_idle`` first looks for a ``_CST`` object under one of the ACPI +objects corresponding to the CPUs in the system (refer to the ACPI specification +[2]_ for the description of ``_CST`` and its output package). Because the +``CPUIdle`` subsystem expects that the list of idle states supplied by the +driver will be suitable for all of the CPUs handled by it and ``intel_idle`` is +registered as the ``CPUIdle`` driver for all of the CPUs in the system, the +driver looks for the first ``_CST`` object returning at least one valid idle +state description and such that all of the idle states included in its return +package are of the FFH (Functional Fixed Hardware) type, which means that the +``MWAIT`` instruction is expected to be used to tell the processor that it can +enter one of them. The return package of that ``_CST`` is then assumed to be +applicable to all of the other CPUs in the system and the idle state +descriptions extracted from it are stored in a preliminary list of idle states +coming from the ACPI tables. [This step is skipped if ``intel_idle`` is +configured to ignore the ACPI tables; see `below <intel-idle-parameters_>`_.] + +Next, the first (index 0) entry in the list of available idle states is +initialized to represent a "polling idle state" (a pseudo-idle state in which +the target CPU continuously fetches and executes instructions), and the +subsequent (real) idle state entries are populated as follows. + +If the processor model at hand is recognized by ``intel_idle``, there is a +(static) table of idle state descriptions for it in the driver. In that case, +the "internal" table is the primary source of information on idle states and the +information from it is copied to the final list of available idle states. If +using the ACPI tables for the enumeration of idle states is not required +(depending on the processor model), all of the listed idle state are enabled by +default (so all of them will be taken into consideration by ``CPUIdle`` +governors during CPU idle state selection). Otherwise, some of the listed idle +states may not be enabled by default if there are no matching entries in the +preliminary list of idle states coming from the ACPI tables. In that case user +space still can enable them later (on a per-CPU basis) with the help of +the ``disable`` idle state attribute in ``sysfs`` (see +:ref:`idle-states-representation` in :doc:`cpuidle`). This basically means that +the idle states "known" to the driver may not be enabled by default if they have +not been exposed by the platform firmware (through the ACPI tables). + +If the given processor model is not recognized by ``intel_idle``, but it +supports ``MWAIT``, the preliminary list of idle states coming from the ACPI +tables is used for building the final list that will be supplied to the +``CPUIdle`` core during driver registration. For each idle state in that list, +the description, ``MWAIT`` hint and exit latency are copied to the corresponding +entry in the final list of idle states. The name of the idle state represented +by it (to be returned by the ``name`` idle state attribute in ``sysfs``) is +"CX_ACPI", where X is the index of that idle state in the final list (note that +the minimum value of X is 1, because 0 is reserved for the "polling" state), and +its target residency is based on the exit latency value. Specifically, for +C1-type idle states the exit latency value is also used as the target residency +(for compatibility with the majority of the "internal" tables of idle states for +various processor models recognized by ``intel_idle``) and for the other idle +state types (C2 and C3) the target residency value is 3 times the exit latency +(again, that is because it reflects the target residency to exit latency ratio +in the majority of cases for the processor models recognized by ``intel_idle``). +All of the idle states in the final list are enabled by default in this case. + + +.. _intel-idle-initialization: + +Initialization +============== + +The initialization of ``intel_idle`` starts with checking if the kernel command +line options forbid the use of the ``MWAIT`` instruction. If that is the case, +an error code is returned right away. + +The next step is to check whether or not the processor model is known to the +driver, which determines the idle states enumeration method (see +`above <intel-idle-enumeration-of-states_>`_), and whether or not the processor +supports ``MWAIT`` (the initialization fails if that is not the case). Then, +the ``MWAIT`` support in the processor is enumerated through ``CPUID`` and the +driver initialization fails if the level of support is not as expected (for +example, if the total number of ``MWAIT`` substates returned is 0). + +Next, if the driver is not configured to ignore the ACPI tables (see +`below <intel-idle-parameters_>`_), the idle states information provided by the +platform firmware is extracted from them. + +Then, ``CPUIdle`` device objects are allocated for all CPUs and the list of +available idle states is created as explained +`above <intel-idle-enumeration-of-states_>`_. + +Finally, ``intel_idle`` is registered with the help of cpuidle_register_driver() +as the ``CPUIdle`` driver for all CPUs in the system and a CPU online callback +for configuring individual CPUs is registered via cpuhp_setup_state(), which +(among other things) causes the callback routine to be invoked for all of the +CPUs present in the system at that time (each CPU executes its own instance of +the callback routine). That routine registers a ``CPUIdle`` device for the CPU +running it (which enables the ``CPUIdle`` subsystem to operate that CPU) and +optionally performs some CPU-specific initialization actions that may be +required for the given processor model. + + +.. _intel-idle-parameters: + +Kernel Command Line Options and Module Parameters +================================================= + +The *x86* architecture support code recognizes three kernel command line +options related to CPU idle time management: ``idle=poll``, ``idle=halt``, +and ``idle=nomwait``. If any of them is present in the kernel command line, the +``MWAIT`` instruction is not allowed to be used, so the initialization of +``intel_idle`` will fail. + +Apart from that there are two module parameters recognized by ``intel_idle`` +itself that can be set via the kernel command line (they cannot be updated via +sysfs, so that is the only way to change their values). + +The ``max_cstate`` parameter value is the maximum idle state index in the list +of idle states supplied to the ``CPUIdle`` core during the registration of the +driver. It is also the maximum number of regular (non-polling) idle states that +can be used by ``intel_idle``, so the enumeration of idle states is terminated +after finding that number of usable idle states (the other idle states that +potentially might have been used if ``max_cstate`` had been greater are not +taken into consideration at all). Setting ``max_cstate`` can prevent +``intel_idle`` from exposing idle states that are regarded as "too deep" for +some reason to the ``CPUIdle`` core, but it does so by making them effectively +invisible until the system is shut down and started again which may not always +be desirable. In practice, it is only really necessary to do that if the idle +states in question cannot be enabled during system startup, because in the +working state of the system the CPU power management quality of service (PM +QoS) feature can be used to prevent ``CPUIdle`` from touching those idle states +even if they have been enumerated (see :ref:`cpu-pm-qos` in :doc:`cpuidle`). +Setting ``max_cstate`` to 0 causes the ``intel_idle`` initialization to fail. + +The ``noacpi`` module parameter (which is recognized by ``intel_idle`` if the +kernel has been configured with ACPI support), can be set to make the driver +ignore the system's ACPI tables entirely (it is unset by default). + + +.. _intel-idle-core-and-package-idle-states: + +Core and Package Levels of Idle States +====================================== + +Typically, in a processor supporting the ``MWAIT`` instruction there are (at +least) two levels of idle states (or C-states). One level, referred to as +"core C-states", covers individual cores in the processor, whereas the other +level, referred to as "package C-states", covers the entire processor package +and it may also involve other components of the system (GPUs, memory +controllers, I/O hubs etc.). + +Some of the ``MWAIT`` hint values allow the processor to use core C-states only +(most importantly, that is the case for the ``MWAIT`` hint value corresponding +to the ``C1`` idle state), but the majority of them give it a license to put +the target core (i.e. the core containing the logical CPU executing ``MWAIT`` +with the given hint value) into a specific core C-state and then (if possible) +to enter a specific package C-state at the deeper level. For example, the +``MWAIT`` hint value representing the ``C3`` idle state allows the processor to +put the target core into the low-power state referred to as "core ``C3``" (or +``CC3``), which happens if all of the logical CPUs (SMT siblings) in that core +have executed ``MWAIT`` with the ``C3`` hint value (or with a hint value +representing a deeper idle state), and in addition to that (in the majority of +cases) it gives the processor a license to put the entire package (possibly +including some non-CPU components such as a GPU or a memory controller) into the +low-power state referred to as "package ``C3``" (or ``PC3``), which happens if +all of the cores have gone into the ``CC3`` state and (possibly) some additional +conditions are satisfied (for instance, if the GPU is covered by ``PC3``, it may +be required to be in a certain GPU-specific low-power state for ``PC3`` to be +reachable). + +As a rule, there is no simple way to make the processor use core C-states only +if the conditions for entering the corresponding package C-states are met, so +the logical CPU executing ``MWAIT`` with a hint value that is not core-level +only (like for ``C1``) must always assume that this may cause the processor to +enter a package C-state. [That is why the exit latency and target residency +values corresponding to the majority of ``MWAIT`` hint values in the "internal" +tables of idle states in ``intel_idle`` reflect the properties of package +C-states.] If using package C-states is not desirable at all, either +:ref:`PM QoS <cpu-pm-qos>` or the ``max_cstate`` module parameter of +``intel_idle`` described `above <intel-idle-parameters_>`_ must be used to +restrict the range of permissible idle states to the ones with core-level only +``MWAIT`` hint values (like ``C1``). + + +References +========== + +.. [1] *Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume 2B*, + https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-2b-manual.html + +.. [2] *Advanced Configuration and Power Interface (ACPI) Specification*, + https://uefi.org/specifications diff --git a/Documentation/admin-guide/pm/working-state.rst b/Documentation/admin-guide/pm/working-state.rst index fc298eb1234b..88f717e59a42 100644 --- a/Documentation/admin-guide/pm/working-state.rst +++ b/Documentation/admin-guide/pm/working-state.rst @@ -8,6 +8,7 @@ Working-State Power Management :maxdepth: 2 cpuidle + intel_idle cpufreq intel_pstate intel_epb diff --git a/Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml b/Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml new file mode 100644 index 000000000000..c9e6c22cb5be --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml @@ -0,0 +1,72 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/memory-controllers/fsl/imx8m-ddrc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: i.MX8M DDR Controller + +maintainers: + - Leonard Crestez <leonard.crestez@nxp.com> + +description: + The DDRC block is integrated in i.MX8M for interfacing with DDR based + memories. + + It supports switching between different frequencies at runtime but during + this process RAM itself becomes briefly inaccessible so actual frequency + switching is implemented by TF-A code which runs from a SRAM area. + + The Linux driver for the DDRC doesn't even map registers (they're included + for the sake of "describing hardware"), it mostly just exposes firmware + capabilities through standard Linux mechanism like devfreq and OPP tables. + +properties: + compatible: + items: + - enum: + - fsl,imx8mn-ddrc + - fsl,imx8mm-ddrc + - fsl,imx8mq-ddrc + - const: fsl,imx8m-ddrc + + reg: + maxItems: 1 + description: + Base address and size of DDRC CTL area. + This is not currently mapped by the imx8m-ddrc driver. + + clocks: + maxItems: 4 + + clock-names: + items: + - const: core + - const: pll + - const: alt + - const: apb + + operating-points-v2: true + opp-table: true + +required: + - reg + - compatible + - clocks + - clock-names + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/imx8mm-clock.h> + ddrc: memory-controller@3d400000 { + compatible = "fsl,imx8mm-ddrc", "fsl,imx8m-ddrc"; + reg = <0x3d400000 0x400000>; + clock-names = "core", "pll", "alt", "apb"; + clocks = <&clk IMX8MM_CLK_DRAM_CORE>, + <&clk IMX8MM_DRAM_PLL>, + <&clk IMX8MM_CLK_DRAM_ALT>, + <&clk IMX8MM_CLK_DRAM_APB>; + operating-points-v2 = <&ddrc_opp_table>; + }; diff --git a/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt b/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt new file mode 100644 index 000000000000..ab0d5ebbad4e --- /dev/null +++ b/Documentation/devicetree/bindings/power/avs/qcom,cpr.txt @@ -0,0 +1,130 @@ +QCOM CPR (Core Power Reduction) + +CPR (Core Power Reduction) is a technology to reduce core power on a CPU +or other device. Each OPP of a device corresponds to a "corner" that has +a range of valid voltages for a particular frequency. While the device is +running at a particular frequency, CPR monitors dynamic factors such as +temperature, etc. and suggests adjustments to the voltage to save power +and meet silicon characteristic requirements. + +- compatible: + Usage: required + Value type: <string> + Definition: should be "qcom,qcs404-cpr", "qcom,cpr" for qcs404 + +- reg: + Usage: required + Value type: <prop-encoded-array> + Definition: base address and size of the rbcpr register region + +- interrupts: + Usage: required + Value type: <prop-encoded-array> + Definition: should specify the CPR interrupt + +- clocks: + Usage: required + Value type: <prop-encoded-array> + Definition: phandle to the reference clock + +- clock-names: + Usage: required + Value type: <stringlist> + Definition: must be "ref" + +- vdd-apc-supply: + Usage: required + Value type: <phandle> + Definition: phandle to the vdd-apc-supply regulator + +- #power-domain-cells: + Usage: required + Value type: <u32> + Definition: should be 0 + +- operating-points-v2: + Usage: required + Value type: <phandle> + Definition: A phandle to the OPP table containing the + performance states supported by the CPR + power domain + +- acc-syscon: + Usage: optional + Value type: <phandle> + Definition: phandle to syscon for writing ACC settings + +- nvmem-cells: + Usage: required + Value type: <phandle> + Definition: phandle to nvmem cells containing the data + that makes up a fuse corner, for each fuse corner. + As well as the CPR fuse revision. + +- nvmem-cell-names: + Usage: required + Value type: <stringlist> + Definition: should be "cpr_quotient_offset1", "cpr_quotient_offset2", + "cpr_quotient_offset3", "cpr_init_voltage1", + "cpr_init_voltage2", "cpr_init_voltage3", "cpr_quotient1", + "cpr_quotient2", "cpr_quotient3", "cpr_ring_osc1", + "cpr_ring_osc2", "cpr_ring_osc3", "cpr_fuse_revision" + for qcs404. + +Example: + + cpr_opp_table: cpr-opp-table { + compatible = "operating-points-v2-qcom-level"; + + cpr_opp1: opp1 { + opp-level = <1>; + qcom,opp-fuse-level = <1>; + }; + cpr_opp2: opp2 { + opp-level = <2>; + qcom,opp-fuse-level = <2>; + }; + cpr_opp3: opp3 { + opp-level = <3>; + qcom,opp-fuse-level = <3>; + }; + }; + + power-controller@b018000 { + compatible = "qcom,qcs404-cpr", "qcom,cpr"; + reg = <0x0b018000 0x1000>; + interrupts = <0 15 IRQ_TYPE_EDGE_RISING>; + clocks = <&xo_board>; + clock-names = "ref"; + vdd-apc-supply = <&pms405_s3>; + #power-domain-cells = <0>; + operating-points-v2 = <&cpr_opp_table>; + acc-syscon = <&tcsr>; + + nvmem-cells = <&cpr_efuse_quot_offset1>, + <&cpr_efuse_quot_offset2>, + <&cpr_efuse_quot_offset3>, + <&cpr_efuse_init_voltage1>, + <&cpr_efuse_init_voltage2>, + <&cpr_efuse_init_voltage3>, + <&cpr_efuse_quot1>, + <&cpr_efuse_quot2>, + <&cpr_efuse_quot3>, + <&cpr_efuse_ring1>, + <&cpr_efuse_ring2>, + <&cpr_efuse_ring3>, + <&cpr_efuse_revision>; + nvmem-cell-names = "cpr_quotient_offset1", + "cpr_quotient_offset2", + "cpr_quotient_offset3", + "cpr_init_voltage1", + "cpr_init_voltage2", + "cpr_init_voltage3", + "cpr_quotient1", + "cpr_quotient2", + "cpr_quotient3", + "cpr_ring_osc1", + "cpr_ring_osc2", + "cpr_ring_osc3", + "cpr_fuse_revision"; + }; |