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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-30 07:47:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-30 07:47:58 -0800
commit893e591b59036f9bc629f55bce715d67bdd266a2 (patch)
tree8f52583958252b2b89d86c0d4d94d9cb44f8a4ee /Documentation/devicetree/bindings/arm
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff)
parentscripts/dtc: Revert "yamltree: Ensure consistent bracketing of properties with phandles" (diff)
downloadlinux-dev-893e591b59036f9bc629f55bce715d67bdd266a2.tar.xz
linux-dev-893e591b59036f9bc629f55bce715d67bdd266a2.zip
Merge tag 'devicetree-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring: - Update dtc to upstream v1.5.1-22-gc40aeb60b47a (plus 1 revert) - Fix for DMA coherent devices on Power - Rework and simplify the DT phandle cache code - DT schema conversions for LEDS, gpio-leds, STM32 dfsdm, STM32 UART, STM32 ROMEM, STM32 watchdog, STM32 DMAs, STM32 mlahb, STM32 RTC, STM32 RCC, STM32 syscon, rs485, Renesas rCar CSI2, Faraday FTIDE010, DWC2, Arm idle-states, Allwinner legacy resets, PRCM and clocks, Allwinner H6 OPP, Allwinner AHCI, Allwinner MBUS, Allwinner A31 CSI, Allwinner h/w codec, Allwinner A10 system ctrl, Allwinner SRAM, Allwinner USB PHY, Renesas CEU, generic PCI host, Arm Versatile PCI - New binding schemas for SATA and PATA controllers, TI and Infineon VR controllers, MAX31730 - New compatible strings for i.MX8QM, WCN3991, renesas,r8a77961-wdt, renesas,etheravb-r8a77961 - Add USB 'super-speed-plus' as a documented speed - Vendor prefixes for broadmobi, calaosystems, kam, and mps - Clean-up the multiple flavors of ST-Ericsson vendor prefixes * tag 'devicetree-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (66 commits) scripts/dtc: Revert "yamltree: Ensure consistent bracketing of properties with phandles" of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc dt-bindings: leds: Convert gpio-leds to DT schema dt-bindings: leds: Convert common LED binding to schema dt-bindings: PCI: Convert generic host binding to DT schema dt-bindings: PCI: Convert Arm Versatile binding to DT schema dt-bindings: Be explicit about installing deps dt-bindings: stm32: convert dfsdm to json-schema dt-bindings: serial: Convert STM32 UART to json-schema dt-bindings: serial: Convert rs485 bindings to json-schema dt-bindings: timer: Use non-empty ranges in example dt-bindings: arm-boards: typo fix dt-bindings: Add TI and Infineon VR Controllers as trivial devices dt-binding: usb: add "super-speed-plus" dt-bindings: rcar-csi2: Convert bindings to json-schema dt-bindings: iio: adc: ad7606: Fix wrong maxItems value dt-bindings: Convert Faraday FTIDE010 to DT schema dt-bindings: Create DT bindings for PATA controllers dt-bindings: Create DT bindings for SATA controllers dt: bindings: add vendor prefix for Kamstrup A/S ...
Diffstat (limited to 'Documentation/devicetree/bindings/arm')
-rw-r--r--Documentation/devicetree/bindings/arm/arm-boards2
-rw-r--r--Documentation/devicetree/bindings/arm/idle-states.txt706
-rw-r--r--Documentation/devicetree/bindings/arm/idle-states.yaml661
-rw-r--r--Documentation/devicetree/bindings/arm/stm32/mlahb.txt37
-rw-r--r--Documentation/devicetree/bindings/arm/stm32/st,mlahb.yaml70
-rw-r--r--Documentation/devicetree/bindings/arm/stm32/st,stm32-syscon.yaml41
-rw-r--r--Documentation/devicetree/bindings/arm/stm32/stm32-syscon.txt16
-rw-r--r--Documentation/devicetree/bindings/arm/sunxi/allwinner,sun4i-a10-mbus.yaml65
-rw-r--r--Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt37
9 files changed, 838 insertions, 797 deletions
diff --git a/Documentation/devicetree/bindings/arm/arm-boards b/Documentation/devicetree/bindings/arm/arm-boards
index b2a9f9f8430b..96b1dad58253 100644
--- a/Documentation/devicetree/bindings/arm/arm-boards
+++ b/Documentation/devicetree/bindings/arm/arm-boards
@@ -121,7 +121,7 @@ Required properties (in root node):
Required nodes:
- soc: some node of the RealView platforms must be the SoC
- node that contain the SoC-specific devices, withe the compatible
+ node that contain the SoC-specific devices, with the compatible
string set to one of these tuples:
"arm,realview-eb-soc", "simple-bus"
"arm,realview-pb1176-soc", "simple-bus"
diff --git a/Documentation/devicetree/bindings/arm/idle-states.txt b/Documentation/devicetree/bindings/arm/idle-states.txt
deleted file mode 100644
index 771f5d20ae18..000000000000
--- a/Documentation/devicetree/bindings/arm/idle-states.txt
+++ /dev/null
@@ -1,706 +0,0 @@
-==========================================
-ARM idle states binding description
-==========================================
-
-==========================================
-1 - Introduction
-==========================================
-
-ARM systems contain HW capable of managing power consumption dynamically,
-where cores can be put in different low-power states (ranging from simple
-wfi to power gating) according to OS PM policies. The CPU states representing
-the range of dynamic idle states that a processor can enter at run-time, can be
-specified through device tree bindings representing the parameters required
-to enter/exit specific idle states on a given processor.
-
-According to the Server Base System Architecture document (SBSA, [3]), the
-power states an ARM CPU can be put into are identified by the following list:
-
-- Running
-- Idle_standby
-- Idle_retention
-- Sleep
-- Off
-
-The power states described in the SBSA document define the basic CPU states on
-top of which ARM platforms implement power management schemes that allow an OS
-PM implementation to put the processor in different idle states (which include
-states listed above; "off" state is not an idle state since it does not have
-wake-up capabilities, hence it is not considered in this document).
-
-Idle state parameters (e.g. entry latency) are platform specific and need to be
-characterized with bindings that provide the required information to OS PM
-code so that it can build the required tables and use them at runtime.
-
-The device tree binding definition for ARM idle states is the subject of this
-document.
-
-===========================================
-2 - idle-states definitions
-===========================================
-
-Idle states are characterized for a specific system through a set of
-timing and energy related properties, that underline the HW behaviour
-triggered upon idle states entry and exit.
-
-The following diagram depicts the CPU execution phases and related timing
-properties required to enter and exit an idle state:
-
-..__[EXEC]__|__[PREP]__|__[ENTRY]__|__[IDLE]__|__[EXIT]__|__[EXEC]__..
- | | | | |
-
- |<------ entry ------->|
- | latency |
- |<- exit ->|
- | latency |
- |<-------- min-residency -------->|
- |<------- wakeup-latency ------->|
-
- Diagram 1: CPU idle state execution phases
-
-EXEC: Normal CPU execution.
-
-PREP: Preparation phase before committing the hardware to idle mode
- like cache flushing. This is abortable on pending wake-up
- event conditions. The abort latency is assumed to be negligible
- (i.e. less than the ENTRY + EXIT duration). If aborted, CPU
- goes back to EXEC. This phase is optional. If not abortable,
- this should be included in the ENTRY phase instead.
-
-ENTRY: The hardware is committed to idle mode. This period must run
- to completion up to IDLE before anything else can happen.
-
-IDLE: This is the actual energy-saving idle period. This may last
- between 0 and infinite time, until a wake-up event occurs.
-
-EXIT: Period during which the CPU is brought back to operational
- mode (EXEC).
-
-entry-latency: Worst case latency required to enter the idle state. The
-exit-latency may be guaranteed only after entry-latency has passed.
-
-min-residency: Minimum period, including preparation and entry, for a given
-idle state to be worthwhile energywise.
-
-wakeup-latency: Maximum delay between the signaling of a wake-up event and the
-CPU being able to execute normal code again. If not specified, this is assumed
-to be entry-latency + exit-latency.
-
-These timing parameters can be used by an OS in different circumstances.
-
-An idle CPU requires the expected min-residency time to select the most
-appropriate idle state based on the expected expiry time of the next IRQ
-(i.e. wake-up) that causes the CPU to return to the EXEC phase.
-
-An operating system scheduler may need to compute the shortest wake-up delay
-for CPUs in the system by detecting how long will it take to get a CPU out
-of an idle state, e.g.:
-
-wakeup-delay = exit-latency + max(entry-latency - (now - entry-timestamp), 0)
-
-In other words, the scheduler can make its scheduling decision by selecting
-(e.g. waking-up) the CPU with the shortest wake-up delay.
-The wake-up delay must take into account the entry latency if that period
-has not expired. The abortable nature of the PREP period can be ignored
-if it cannot be relied upon (e.g. the PREP deadline may occur much sooner than
-the worst case since it depends on the CPU operating conditions, i.e. caches
-state).
-
-An OS has to reliably probe the wakeup-latency since some devices can enforce
-latency constraint guarantees to work properly, so the OS has to detect the
-worst case wake-up latency it can incur if a CPU is allowed to enter an
-idle state, and possibly to prevent that to guarantee reliable device
-functioning.
-
-The min-residency time parameter deserves further explanation since it is
-expressed in time units but must factor in energy consumption coefficients.
-
-The energy consumption of a cpu when it enters a power state can be roughly
-characterised by the following graph:
-
- |
- |
- |
- e |
- n | /---
- e | /------
- r | /------
- g | /-----
- y | /------
- | ----
- | /|
- | / |
- | / |
- | / |
- | / |
- | / |
- |/ |
- -----|-------+----------------------------------
- 0| 1 time(ms)
-
- Graph 1: Energy vs time example
-
-The graph is split in two parts delimited by time 1ms on the X-axis.
-The graph curve with X-axis values = { x | 0 < x < 1ms } has a steep slope
-and denotes the energy costs incurred while entering and leaving the idle
-state.
-The graph curve in the area delimited by X-axis values = {x | x > 1ms } has
-shallower slope and essentially represents the energy consumption of the idle
-state.
-
-min-residency is defined for a given idle state as the minimum expected
-residency time for a state (inclusive of preparation and entry) after
-which choosing that state become the most energy efficient option. A good
-way to visualise this, is by taking the same graph above and comparing some
-states energy consumptions plots.
-
-For sake of simplicity, let's consider a system with two idle states IDLE1,
-and IDLE2:
-
- |
- |
- |
- | /-- IDLE1
- e | /---
- n | /----
- e | /---
- r | /-----/--------- IDLE2
- g | /-------/---------
- y | ------------ /---|
- | / /---- |
- | / /--- |
- | / /---- |
- | / /--- |
- | --- |
- | / |
- | / |
- |/ | time
- ---/----------------------------+------------------------
- |IDLE1-energy < IDLE2-energy | IDLE2-energy < IDLE1-energy
- |
- IDLE2-min-residency
-
- Graph 2: idle states min-residency example
-
-In graph 2 above, that takes into account idle states entry/exit energy
-costs, it is clear that if the idle state residency time (i.e. time till next
-wake-up IRQ) is less than IDLE2-min-residency, IDLE1 is the better idle state
-choice energywise.
-
-This is mainly down to the fact that IDLE1 entry/exit energy costs are lower
-than IDLE2.
-
-However, the lower power consumption (i.e. shallower energy curve slope) of
-idle state IDLE2 implies that after a suitable time, IDLE2 becomes more energy
-efficient.
-
-The time at which IDLE2 becomes more energy efficient than IDLE1 (and other
-shallower states in a system with multiple idle states) is defined
-IDLE2-min-residency and corresponds to the time when energy consumption of
-IDLE1 and IDLE2 states breaks even.
-
-The definitions provided in this section underpin the idle states
-properties specification that is the subject of the following sections.
-
-===========================================
-3 - idle-states node
-===========================================
-
-ARM processor idle states are defined within the idle-states node, which is
-a direct child of the cpus node [1] and provides a container where the
-processor idle states, defined as device tree nodes, are listed.
-
-- idle-states node
-
- Usage: Optional - On ARM systems, it is a container of processor idle
- states nodes. If the system does not provide CPU
- power management capabilities, or the processor just
- supports idle_standby, an idle-states node is not
- required.
-
- Description: idle-states node is a container node, where its
- subnodes describe the CPU idle states.
-
- Node name must be "idle-states".
-
- The idle-states node's parent node must be the cpus node.
-
- The idle-states node's child nodes can be:
-
- - one or more state nodes
-
- Any other configuration is considered invalid.
-
- An idle-states node defines the following properties:
-
- - entry-method
- Value type: <stringlist>
- Usage and definition depend on ARM architecture version.
- # On ARM v8 64-bit this property is required and must
- be:
- - "psci"
- # On ARM 32-bit systems this property is optional
-
-This assumes that the "enable-method" property is set to "psci" in the cpu
-node[6] that is responsible for setting up CPU idle management in the OS
-implementation.
-
-The nodes describing the idle states (state) can only be defined
-within the idle-states node, any other configuration is considered invalid
-and therefore must be ignored.
-
-===========================================
-4 - state node
-===========================================
-
-A state node represents an idle state description and must be defined as
-follows:
-
-- state node
-
- Description: must be child of the idle-states node
-
- The state node name shall follow standard device tree naming
- rules ([5], 2.2.1 "Node names"), in particular state nodes which
- are siblings within a single common parent must be given a unique name.
-
- The idle state entered by executing the wfi instruction (idle_standby
- SBSA,[3][4]) is considered standard on all ARM platforms and therefore
- must not be listed.
-
- With the definitions provided above, the following list represents
- the valid properties for a state node:
-
- - compatible
- Usage: Required
- Value type: <stringlist>
- Definition: Must be "arm,idle-state".
-
- - local-timer-stop
- Usage: See definition
- Value type: <none>
- Definition: if present the CPU local timer control logic is
- lost on state entry, otherwise it is retained.
-
- - entry-latency-us
- Usage: Required
- Value type: <prop-encoded-array>
- Definition: u32 value representing worst case latency in
- microseconds required to enter the idle state.
-
- - exit-latency-us
- Usage: Required
- Value type: <prop-encoded-array>
- Definition: u32 value representing worst case latency
- in microseconds required to exit the idle state.
- The exit-latency-us duration may be guaranteed
- only after entry-latency-us has passed.
-
- - min-residency-us
- Usage: Required
- Value type: <prop-encoded-array>
- Definition: u32 value representing minimum residency duration
- in microseconds, inclusive of preparation and
- entry, for this idle state to be considered
- worthwhile energy wise (refer to section 2 of
- this document for a complete description).
-
- - wakeup-latency-us:
- Usage: Optional
- Value type: <prop-encoded-array>
- Definition: u32 value representing maximum delay between the
- signaling of a wake-up event and the CPU being
- able to execute normal code again. If omitted,
- this is assumed to be equal to:
-
- entry-latency-us + exit-latency-us
-
- It is important to supply this value on systems
- where the duration of PREP phase (see diagram 1,
- section 2) is non-neglibigle.
- In such systems entry-latency-us + exit-latency-us
- will exceed wakeup-latency-us by this duration.
-
- - status:
- Usage: Optional
- Value type: <string>
- Definition: A standard device tree property [5] that indicates
- the operational status of an idle-state.
- If present, it shall be:
- "okay": to indicate that the idle state is
- operational.
- "disabled": to indicate that the idle state has
- been disabled in firmware so it is not
- operational.
- If the property is not present the idle-state must
- be considered operational.
-
- - idle-state-name:
- Usage: Optional
- Value type: <string>
- Definition: A string used as a descriptive name for the idle
- state.
-
- In addition to the properties listed above, a state node may require
- additional properties specific to the entry-method defined in the
- idle-states node. Please refer to the entry-method bindings
- documentation for properties definitions.
-
-===========================================
-4 - Examples
-===========================================
-
-Example 1 (ARM 64-bit, 16-cpu system, PSCI enable-method):
-
-cpus {
- #size-cells = <0>;
- #address-cells = <2>;
-
- CPU0: cpu@0 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x0>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU1: cpu@1 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x1>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU2: cpu@100 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x100>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU3: cpu@101 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x101>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU4: cpu@10000 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x10000>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU5: cpu@10001 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x10001>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU6: cpu@10100 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x10100>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU7: cpu@10101 {
- device_type = "cpu";
- compatible = "arm,cortex-a57";
- reg = <0x0 0x10101>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
- &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU8: cpu@100000000 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x0>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU9: cpu@100000001 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x1>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU10: cpu@100000100 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x100>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU11: cpu@100000101 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x101>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU12: cpu@100010000 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x10000>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU13: cpu@100010001 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x10001>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU14: cpu@100010100 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x10100>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- CPU15: cpu@100010101 {
- device_type = "cpu";
- compatible = "arm,cortex-a53";
- reg = <0x1 0x10101>;
- enable-method = "psci";
- cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
- &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
- };
-
- idle-states {
- entry-method = "psci";
-
- CPU_RETENTION_0_0: cpu-retention-0-0 {
- compatible = "arm,idle-state";
- arm,psci-suspend-param = <0x0010000>;
- entry-latency-us = <20>;
- exit-latency-us = <40>;
- min-residency-us = <80>;
- };
-
- CLUSTER_RETENTION_0: cluster-retention-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x1010000>;
- entry-latency-us = <50>;
- exit-latency-us = <100>;
- min-residency-us = <250>;
- wakeup-latency-us = <130>;
- };
-
- CPU_SLEEP_0_0: cpu-sleep-0-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x0010000>;
- entry-latency-us = <250>;
- exit-latency-us = <500>;
- min-residency-us = <950>;
- };
-
- CLUSTER_SLEEP_0: cluster-sleep-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x1010000>;
- entry-latency-us = <600>;
- exit-latency-us = <1100>;
- min-residency-us = <2700>;
- wakeup-latency-us = <1500>;
- };
-
- CPU_RETENTION_1_0: cpu-retention-1-0 {
- compatible = "arm,idle-state";
- arm,psci-suspend-param = <0x0010000>;
- entry-latency-us = <20>;
- exit-latency-us = <40>;
- min-residency-us = <90>;
- };
-
- CLUSTER_RETENTION_1: cluster-retention-1 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x1010000>;
- entry-latency-us = <50>;
- exit-latency-us = <100>;
- min-residency-us = <270>;
- wakeup-latency-us = <100>;
- };
-
- CPU_SLEEP_1_0: cpu-sleep-1-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x0010000>;
- entry-latency-us = <70>;
- exit-latency-us = <100>;
- min-residency-us = <300>;
- wakeup-latency-us = <150>;
- };
-
- CLUSTER_SLEEP_1: cluster-sleep-1 {
- compatible = "arm,idle-state";
- local-timer-stop;
- arm,psci-suspend-param = <0x1010000>;
- entry-latency-us = <500>;
- exit-latency-us = <1200>;
- min-residency-us = <3500>;
- wakeup-latency-us = <1300>;
- };
- };
-
-};
-
-Example 2 (ARM 32-bit, 8-cpu system, two clusters):
-
-cpus {
- #size-cells = <0>;
- #address-cells = <1>;
-
- CPU0: cpu@0 {
- device_type = "cpu";
- compatible = "arm,cortex-a15";
- reg = <0x0>;
- cpu-idle-states = <&CPU_SLEEP_0_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU1: cpu@1 {
- device_type = "cpu";
- compatible = "arm,cortex-a15";
- reg = <0x1>;
- cpu-idle-states = <&CPU_SLEEP_0_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU2: cpu@2 {
- device_type = "cpu";
- compatible = "arm,cortex-a15";
- reg = <0x2>;
- cpu-idle-states = <&CPU_SLEEP_0_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU3: cpu@3 {
- device_type = "cpu";
- compatible = "arm,cortex-a15";
- reg = <0x3>;
- cpu-idle-states = <&CPU_SLEEP_0_0 &CLUSTER_SLEEP_0>;
- };
-
- CPU4: cpu@100 {
- device_type = "cpu";
- compatible = "arm,cortex-a7";
- reg = <0x100>;
- cpu-idle-states = <&CPU_SLEEP_1_0 &CLUSTER_SLEEP_1>;
- };
-
- CPU5: cpu@101 {
- device_type = "cpu";
- compatible = "arm,cortex-a7";
- reg = <0x101>;
- cpu-idle-states = <&CPU_SLEEP_1_0 &CLUSTER_SLEEP_1>;
- };
-
- CPU6: cpu@102 {
- device_type = "cpu";
- compatible = "arm,cortex-a7";
- reg = <0x102>;
- cpu-idle-states = <&CPU_SLEEP_1_0 &CLUSTER_SLEEP_1>;
- };
-
- CPU7: cpu@103 {
- device_type = "cpu";
- compatible = "arm,cortex-a7";
- reg = <0x103>;
- cpu-idle-states = <&CPU_SLEEP_1_0 &CLUSTER_SLEEP_1>;
- };
-
- idle-states {
- CPU_SLEEP_0_0: cpu-sleep-0-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- entry-latency-us = <200>;
- exit-latency-us = <100>;
- min-residency-us = <400>;
- wakeup-latency-us = <250>;
- };
-
- CLUSTER_SLEEP_0: cluster-sleep-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- entry-latency-us = <500>;
- exit-latency-us = <1500>;
- min-residency-us = <2500>;
- wakeup-latency-us = <1700>;
- };
-
- CPU_SLEEP_1_0: cpu-sleep-1-0 {
- compatible = "arm,idle-state";
- local-timer-stop;
- entry-latency-us = <300>;
- exit-latency-us = <500>;
- min-residency-us = <900>;
- wakeup-latency-us = <600>;
- };
-
- CLUSTER_SLEEP_1: cluster-sleep-1 {
- compatible = "arm,idle-state";
- local-timer-stop;
- entry-latency-us = <800>;
- exit-latency-us = <2000>;
- min-residency-us = <6500>;
- wakeup-latency-us = <2300>;
- };
- };
-
-};
-
-===========================================
-5 - References
-===========================================
-
-[1] ARM Linux Kernel documentation - CPUs bindings
- Documentation/devicetree/bindings/arm/cpus.yaml
-
-[2] ARM Linux Kernel documentation - PSCI bindings
- Documentation/devicetree/bindings/arm/psci.yaml
-
-[3] ARM Server Base System Architecture (SBSA)
- http://infocenter.arm.com/help/index.jsp
-
-[4] ARM Architecture Reference Manuals
- http://infocenter.arm.com/help/index.jsp
-
-[5] Devicetree Specification
- https://www.devicetree.org/specifications/
-
-[6] ARM Linux Kernel documentation - Booting AArch64 Linux
- Documentation/arm64/booting.rst
diff --git a/Documentation/devicetree/bindings/arm/idle-states.yaml b/Documentation/devicetree/bindings/arm/idle-states.yaml
new file mode 100644
index 000000000000..ea805c1e6b20
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/idle-states.yaml
@@ -0,0 +1,661 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/idle-states.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM idle states binding description
+
+maintainers:
+ - Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+
+description: |+
+ ==========================================
+ 1 - Introduction
+ ==========================================
+
+ ARM systems contain HW capable of managing power consumption dynamically,
+ where cores can be put in different low-power states (ranging from simple wfi
+ to power gating) according to OS PM policies. The CPU states representing the
+ range of dynamic idle states that a processor can enter at run-time, can be
+ specified through device tree bindings representing the parameters required to
+ enter/exit specific idle states on a given processor.
+
+ According to the Server Base System Architecture document (SBSA, [3]), the
+ power states an ARM CPU can be put into are identified by the following list:
+
+ - Running
+ - Idle_standby
+ - Idle_retention
+ - Sleep
+ - Off
+
+ The power states described in the SBSA document define the basic CPU states on
+ top of which ARM platforms implement power management schemes that allow an OS
+ PM implementation to put the processor in different idle states (which include
+ states listed above; "off" state is not an idle state since it does not have
+ wake-up capabilities, hence it is not considered in this document).
+
+ Idle state parameters (e.g. entry latency) are platform specific and need to
+ be characterized with bindings that provide the required information to OS PM
+ code so that it can build the required tables and use them at runtime.
+
+ The device tree binding definition for ARM idle states is the subject of this
+ document.
+
+ ===========================================
+ 2 - idle-states definitions
+ ===========================================
+
+ Idle states are characterized for a specific system through a set of
+ timing and energy related properties, that underline the HW behaviour
+ triggered upon idle states entry and exit.
+
+ The following diagram depicts the CPU execution phases and related timing
+ properties required to enter and exit an idle state:
+
+ ..__[EXEC]__|__[PREP]__|__[ENTRY]__|__[IDLE]__|__[EXIT]__|__[EXEC]__..
+ | | | | |
+
+ |<------ entry ------->|
+ | latency |
+ |<- exit ->|
+ | latency |
+ |<-------- min-residency -------->|
+ |<------- wakeup-latency ------->|
+
+ Diagram 1: CPU idle state execution phases
+
+ EXEC: Normal CPU execution.
+
+ PREP: Preparation phase before committing the hardware to idle mode
+ like cache flushing. This is abortable on pending wake-up
+ event conditions. The abort latency is assumed to be negligible
+ (i.e. less than the ENTRY + EXIT duration). If aborted, CPU
+ goes back to EXEC. This phase is optional. If not abortable,
+ this should be included in the ENTRY phase instead.
+
+ ENTRY: The hardware is committed to idle mode. This period must run
+ to completion up to IDLE before anything else can happen.
+
+ IDLE: This is the actual energy-saving idle period. This may last
+ between 0 and infinite time, until a wake-up event occurs.
+
+ EXIT: Period during which the CPU is brought back to operational
+ mode (EXEC).
+
+ entry-latency: Worst case latency required to enter the idle state. The
+ exit-latency may be guaranteed only after entry-latency has passed.
+
+ min-residency: Minimum period, including preparation and entry, for a given
+ idle state to be worthwhile energywise.
+
+ wakeup-latency: Maximum delay between the signaling of a wake-up event and the
+ CPU being able to execute normal code again. If not specified, this is assumed
+ to be entry-latency + exit-latency.
+
+ These timing parameters can be used by an OS in different circumstances.
+
+ An idle CPU requires the expected min-residency time to select the most
+ appropriate idle state based on the expected expiry time of the next IRQ
+ (i.e. wake-up) that causes the CPU to return to the EXEC phase.
+
+ An operating system scheduler may need to compute the shortest wake-up delay
+ for CPUs in the system by detecting how long will it take to get a CPU out
+ of an idle state, e.g.:
+
+ wakeup-delay = exit-latency + max(entry-latency - (now - entry-timestamp), 0)
+
+ In other words, the scheduler can make its scheduling decision by selecting
+ (e.g. waking-up) the CPU with the shortest wake-up delay.
+ The wake-up delay must take into account the entry latency if that period
+ has not expired. The abortable nature of the PREP period can be ignored
+ if it cannot be relied upon (e.g. the PREP deadline may occur much sooner than
+ the worst case since it depends on the CPU operating conditions, i.e. caches
+ state).
+
+ An OS has to reliably probe the wakeup-latency since some devices can enforce
+ latency constraint guarantees to work properly, so the OS has to detect the
+ worst case wake-up latency it can incur if a CPU is allowed to enter an
+ idle state, and possibly to prevent that to guarantee reliable device
+ functioning.
+
+ The min-residency time parameter deserves further explanation since it is
+ expressed in time units but must factor in energy consumption coefficients.
+
+ The energy consumption of a cpu when it enters a power state can be roughly
+ characterised by the following graph:
+
+ |
+ |
+ |
+ e |
+ n | /---
+ e | /------
+ r | /------
+ g | /-----
+ y | /------
+ | ----
+ | /|
+ | / |
+ | / |
+ | / |
+ | / |
+ | / |
+ |/ |
+ -----|-------+----------------------------------
+ 0| 1 time(ms)
+
+ Graph 1: Energy vs time example
+
+ The graph is split in two parts delimited by time 1ms on the X-axis.
+ The graph curve with X-axis values = { x | 0 < x < 1ms } has a steep slope
+ and denotes the energy costs incurred while entering and leaving the idle
+ state.
+ The graph curve in the area delimited by X-axis values = {x | x > 1ms } has
+ shallower slope and essentially represents the energy consumption of the idle
+ state.
+
+ min-residency is defined for a given idle state as the minimum expected
+ residency time for a state (inclusive of preparation and entry) after
+ which choosing that state become the most energy efficient option. A good
+ way to visualise this, is by taking the same graph above and comparing some
+ states energy consumptions plots.
+
+ For sake of simplicity, let's consider a system with two idle states IDLE1,
+ and IDLE2:
+
+ |
+ |
+ |
+ | /-- IDLE1
+ e | /---
+ n | /----
+ e | /---
+ r | /-----/--------- IDLE2
+ g | /-------/---------
+ y | ------------ /---|
+ | / /---- |
+ | / /--- |
+ | / /---- |
+ | / /--- |
+ | --- |
+ | / |
+ | / |
+ |/ | time
+ ---/----------------------------+------------------------
+ |IDLE1-energy < IDLE2-energy | IDLE2-energy < IDLE1-energy
+ |
+ IDLE2-min-residency
+
+ Graph 2: idle states min-residency example
+
+ In graph 2 above, that takes into account idle states entry/exit energy
+ costs, it is clear that if the idle state residency time (i.e. time till next
+ wake-up IRQ) is less than IDLE2-min-residency, IDLE1 is the better idle state
+ choice energywise.
+
+ This is mainly down to the fact that IDLE1 entry/exit energy costs are lower
+ than IDLE2.
+
+ However, the lower power consumption (i.e. shallower energy curve slope) of
+ idle state IDLE2 implies that after a suitable time, IDLE2 becomes more energy
+ efficient.
+
+ The time at which IDLE2 becomes more energy efficient than IDLE1 (and other
+ shallower states in a system with multiple idle states) is defined
+ IDLE2-min-residency and corresponds to the time when energy consumption of
+ IDLE1 and IDLE2 states breaks even.
+
+ The definitions provided in this section underpin the idle states
+ properties specification that is the subject of the following sections.
+
+ ===========================================
+ 3 - idle-states node
+ ===========================================
+
+ ARM processor idle states are defined within the idle-states node, which is
+ a direct child of the cpus node [1] and provides a container where the
+ processor idle states, defined as device tree nodes, are listed.
+
+ On ARM systems, it is a container of processor idle states nodes. If the
+ system does not provide CPU power management capabilities, or the processor
+ just supports idle_standby, an idle-states node is not required.
+
+ ===========================================
+ 4 - References
+ ===========================================
+
+ [1] ARM Linux Kernel documentation - CPUs bindings
+ Documentation/devicetree/bindings/arm/cpus.yaml
+
+ [2] ARM Linux Kernel documentation - PSCI bindings
+ Documentation/devicetree/bindings/arm/psci.yaml
+
+ [3] ARM Server Base System Architecture (SBSA)
+ http://infocenter.arm.com/help/index.jsp
+
+ [4] ARM Architecture Reference Manuals
+ http://infocenter.arm.com/help/index.jsp
+
+ [6] ARM Linux Kernel documentation - Booting AArch64 Linux
+ Documentation/arm64/booting.rst
+
+properties:
+ $nodename:
+ const: idle-states
+
+ entry-method:
+ description: |
+ Usage and definition depend on ARM architecture version.
+
+ On ARM v8 64-bit this property is required.
+ On ARM 32-bit systems this property is optional
+
+ This assumes that the "enable-method" property is set to "psci" in the cpu
+ node[6] that is responsible for setting up CPU idle management in the OS
+ implementation.
+ const: psci
+
+patternProperties:
+ "^(cpu|cluster)-":
+ type: object
+ description: |
+ Each state node represents an idle state description and must be defined
+ as follows.
+
+ The idle state entered by executing the wfi instruction (idle_standby
+ SBSA,[3][4]) is considered standard on all ARM platforms and therefore
+ must not be listed.
+
+ In addition to the properties listed above, a state node may require
+ additional properties specific to the entry-method defined in the
+ idle-states node. Please refer to the entry-method bindings
+ documentation for properties definitions.
+
+ properties:
+ compatible:
+ const: arm,idle-state
+
+ local-timer-stop:
+ description:
+ If present the CPU local timer control logic is
+ lost on state entry, otherwise it is retained.
+ type: boolean
+
+ entry-latency-us:
+ description:
+ Worst case latency in microseconds required to enter the idle state.
+
+ exit-latency-us:
+ description:
+ Worst case latency in microseconds required to exit the idle state.
+ The exit-latency-us duration may be guaranteed only after
+ entry-latency-us has passed.
+
+ min-residency-us:
+ description:
+ Minimum residency duration in microseconds, inclusive of preparation
+ and entry, for this idle state to be considered worthwhile energy wise
+ (refer to section 2 of this document for a complete description).
+
+ wakeup-latency-us:
+ description: |
+ Maximum delay between the signaling of a wake-up event and the CPU
+ being able to execute normal code again. If omitted, this is assumed
+ to be equal to:
+
+ entry-latency-us + exit-latency-us
+
+ It is important to supply this value on systems where the duration of
+ PREP phase (see diagram 1, section 2) is non-neglibigle. In such
+ systems entry-latency-us + exit-latency-us will exceed
+ wakeup-latency-us by this duration.
+
+ idle-state-name:
+ $ref: /schemas/types.yaml#definitions/string
+ description:
+ A string used as a descriptive name for the idle state.
+
+ required:
+ - compatible
+ - entry-latency-us
+ - exit-latency-us
+ - min-residency-us
+
+additionalProperties: false
+
+examples:
+ - |
+
+ cpus {
+ #size-cells = <0>;
+ #address-cells = <2>;
+
+ cpu@0 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x0>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@1 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x1>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@100 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x100>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@101 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x101>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@10000 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x10000>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@10001 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x10001>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@10100 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x10100>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@10101 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a57";
+ reg = <0x0 0x10101>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_0_0 &CPU_SLEEP_0_0
+ &CLUSTER_RETENTION_0 &CLUSTER_SLEEP_0>;
+ };
+
+ cpu@100000000 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x0>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100000001 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x1>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100000100 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x100>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100000101 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x101>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100010000 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x10000>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100010001 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x10001>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100010100 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x10100>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ cpu@100010101 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a53";
+ reg = <0x1 0x10101>;
+ enable-method = "psci";
+ cpu-idle-states = <&CPU_RETENTION_1_0 &CPU_SLEEP_1_0
+ &CLUSTER_RETENTION_1 &CLUSTER_SLEEP_1>;
+ };
+
+ idle-states {
+ entry-method = "psci";
+
+ CPU_RETENTION_0_0: cpu-retention-0-0 {
+ compatible = "arm,idle-state";
+ arm,psci-suspend-param = <0x0010000>;
+ entry-latency-us = <20>;
+ exit-latency-us = <40>;
+ min-residency-us = <80>;
+ };
+
+ CLUSTER_RETENTION_0: cluster-retention-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x1010000>;
+ entry-latency-us = <50>;
+ exit-latency-us = <100>;
+ min-residency-us = <250>;
+ wakeup-latency-us = <130>;
+ };
+
+ CPU_SLEEP_0_0: cpu-sleep-0-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x0010000>;
+ entry-latency-us = <250>;
+ exit-latency-us = <500>;
+ min-residency-us = <950>;
+ };
+
+ CLUSTER_SLEEP_0: cluster-sleep-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x1010000>;
+ entry-latency-us = <600>;
+ exit-latency-us = <1100>;
+ min-residency-us = <2700>;
+ wakeup-latency-us = <1500>;
+ };
+
+ CPU_RETENTION_1_0: cpu-retention-1-0 {
+ compatible = "arm,idle-state";
+ arm,psci-suspend-param = <0x0010000>;
+ entry-latency-us = <20>;
+ exit-latency-us = <40>;
+ min-residency-us = <90>;
+ };
+
+ CLUSTER_RETENTION_1: cluster-retention-1 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x1010000>;
+ entry-latency-us = <50>;
+ exit-latency-us = <100>;
+ min-residency-us = <270>;
+ wakeup-latency-us = <100>;
+ };
+
+ CPU_SLEEP_1_0: cpu-sleep-1-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x0010000>;
+ entry-latency-us = <70>;
+ exit-latency-us = <100>;
+ min-residency-us = <300>;
+ wakeup-latency-us = <150>;
+ };
+
+ CLUSTER_SLEEP_1: cluster-sleep-1 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ arm,psci-suspend-param = <0x1010000>;
+ entry-latency-us = <500>;
+ exit-latency-us = <1200>;
+ min-residency-us = <3500>;
+ wakeup-latency-us = <1300>;
+ };
+ };
+ };
+
+ - |
+ // Example 2 (ARM 32-bit, 8-cpu system, two clusters):
+
+ cpus {
+ #size-cells = <0>;
+ #address-cells = <1>;
+
+ cpu@0 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a15";
+ reg = <0x0>;
+ cpu-idle-states = <&cpu_sleep_0_0 &cluster_sleep_0>;
+ };
+
+ cpu@1 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a15";
+ reg = <0x1>;
+ cpu-idle-states = <&cpu_sleep_0_0 &cluster_sleep_0>;
+ };
+
+ cpu@2 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a15";
+ reg = <0x2>;
+ cpu-idle-states = <&cpu_sleep_0_0 &cluster_sleep_0>;
+ };
+
+ cpu@3 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a15";
+ reg = <0x3>;
+ cpu-idle-states = <&cpu_sleep_0_0 &cluster_sleep_0>;
+ };
+
+ cpu@100 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a7";
+ reg = <0x100>;
+ cpu-idle-states = <&cpu_sleep_1_0 &cluster_sleep_1>;
+ };
+
+ cpu@101 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a7";
+ reg = <0x101>;
+ cpu-idle-states = <&cpu_sleep_1_0 &cluster_sleep_1>;
+ };
+
+ cpu@102 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a7";
+ reg = <0x102>;
+ cpu-idle-states = <&cpu_sleep_1_0 &cluster_sleep_1>;
+ };
+
+ cpu@103 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a7";
+ reg = <0x103>;
+ cpu-idle-states = <&cpu_sleep_1_0 &cluster_sleep_1>;
+ };
+
+ idle-states {
+ cpu_sleep_0_0: cpu-sleep-0-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ entry-latency-us = <200>;
+ exit-latency-us = <100>;
+ min-residency-us = <400>;
+ wakeup-latency-us = <250>;
+ };
+
+ cluster_sleep_0: cluster-sleep-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ entry-latency-us = <500>;
+ exit-latency-us = <1500>;
+ min-residency-us = <2500>;
+ wakeup-latency-us = <1700>;
+ };
+
+ cpu_sleep_1_0: cpu-sleep-1-0 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ entry-latency-us = <300>;
+ exit-latency-us = <500>;
+ min-residency-us = <900>;
+ wakeup-latency-us = <600>;
+ };
+
+ cluster_sleep_1: cluster-sleep-1 {
+ compatible = "arm,idle-state";
+ local-timer-stop;
+ entry-latency-us = <800>;
+ exit-latency-us = <2000>;
+ min-residency-us = <6500>;
+ wakeup-latency-us = <2300>;
+ };
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/stm32/mlahb.txt b/Documentation/devicetree/bindings/arm/stm32/mlahb.txt
deleted file mode 100644
index 25307aa1eb9b..000000000000
--- a/Documentation/devicetree/bindings/arm/stm32/mlahb.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-ML-AHB interconnect bindings
-
-These bindings describe the STM32 SoCs ML-AHB interconnect bus which connects
-a Cortex-M subsystem with dedicated memories.
-The MCU SRAM and RETRAM memory parts can be accessed through different addresses
-(see "RAM aliases" in [1]) using different buses (see [2]) : balancing the
-Cortex-M firmware accesses among those ports allows to tune the system
-performance.
-
-[1]: https://www.st.com/resource/en/reference_manual/dm00327659.pdf
-[2]: https://wiki.st.com/stm32mpu/wiki/STM32MP15_RAM_mapping
-
-Required properties:
-- compatible: should be "simple-bus"
-- dma-ranges: describes memory addresses translation between the local CPU and
- the remote Cortex-M processor. Each memory region, is declared with
- 3 parameters:
- - param 1: device base address (Cortex-M processor address)
- - param 2: physical base address (local CPU address)
- - param 3: size of the memory region.
-
-The Cortex-M remote processor accessed via the mlahb interconnect is described
-by a child node.
-
-Example:
-mlahb {
- compatible = "simple-bus";
- #address-cells = <1>;
- #size-cells = <1>;
- dma-ranges = <0x00000000 0x38000000 0x10000>,
- <0x10000000 0x10000000 0x60000>,
- <0x30000000 0x30000000 0x60000>;
-
- m4_rproc: m4@10000000 {
- ...
- };
-};
diff --git a/Documentation/devicetree/bindings/arm/stm32/st,mlahb.yaml b/Documentation/devicetree/bindings/arm/stm32/st,mlahb.yaml
new file mode 100644
index 000000000000..68917bb7c7e8
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/stm32/st,mlahb.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/arm/stm32/st,mlahb.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: STMicroelectronics STM32 ML-AHB interconnect bindings
+
+maintainers:
+ - Fabien Dessenne <fabien.dessenne@st.com>
+ - Arnaud Pouliquen <arnaud.pouliquen@st.com>
+
+description: |
+ These bindings describe the STM32 SoCs ML-AHB interconnect bus which connects
+ a Cortex-M subsystem with dedicated memories. The MCU SRAM and RETRAM memory
+ parts can be accessed through different addresses (see "RAM aliases" in [1])
+ using different buses (see [2]): balancing the Cortex-M firmware accesses
+ among those ports allows to tune the system performance.
+ [1]: https://www.st.com/resource/en/reference_manual/dm00327659.pdf
+ [2]: https://wiki.st.com/stm32mpu/wiki/STM32MP15_RAM_mapping
+
+allOf:
+ - $ref: /schemas/simple-bus.yaml#
+
+properties:
+ compatible:
+ contains:
+ enum:
+ - st,mlahb
+
+ dma-ranges:
+ description: |
+ Describe memory addresses translation between the local CPU and the
+ remote Cortex-M processor. Each memory region, is declared with
+ 3 parameters:
+ - param 1: device base address (Cortex-M processor address)
+ - param 2: physical base address (local CPU address)
+ - param 3: size of the memory region.
+ maxItems: 3
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 1
+
+required:
+ - compatible
+ - '#address-cells'
+ - '#size-cells'
+ - dma-ranges
+
+examples:
+ - |
+ mlahb: ahb {
+ compatible = "st,mlahb", "simple-bus";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x10000000 0x40000>;
+ ranges;
+ dma-ranges = <0x00000000 0x38000000 0x10000>,
+ <0x10000000 0x10000000 0x60000>,
+ <0x30000000 0x30000000 0x60000>;
+
+ m4_rproc: m4@10000000 {
+ reg = <0x10000000 0x40000>;
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/stm32/st,stm32-syscon.yaml b/Documentation/devicetree/bindings/arm/stm32/st,stm32-syscon.yaml
new file mode 100644
index 000000000000..0dedf94c8578
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/stm32/st,stm32-syscon.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/arm/stm32/st,stm32-syscon.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: STMicroelectronics STM32 Platforms System Controller bindings
+
+maintainers:
+ - Alexandre Torgue <alexandre.torgue@st.com>
+ - Christophe Roullier <christophe.roullier@st.com>
+
+properties:
+ compatible:
+ oneOf:
+ - items:
+ - enum:
+ - st,stm32mp157-syscfg
+ - const: syscon
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - clocks
+
+examples:
+ - |
+ #include <dt-bindings/clock/stm32mp1-clks.h>
+ syscfg: syscon@50020000 {
+ compatible = "st,stm32mp157-syscfg", "syscon";
+ reg = <0x50020000 0x400>;
+ clocks = <&rcc SYSCFG>;
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/stm32/stm32-syscon.txt b/Documentation/devicetree/bindings/arm/stm32/stm32-syscon.txt
deleted file mode 100644
index c92d411fd023..000000000000
--- a/Documentation/devicetree/bindings/arm/stm32/stm32-syscon.txt
+++ /dev/null
@@ -1,16 +0,0 @@
-STMicroelectronics STM32 Platforms System Controller
-
-Properties:
- - compatible : should contain two values. First value must be :
- - " st,stm32mp157-syscfg " - for stm32mp157 based SoCs,
- second value must be always "syscon".
- - reg : offset and length of the register set.
- - clocks: phandle to the syscfg clock
-
- Example:
- syscfg: syscon@50020000 {
- compatible = "st,stm32mp157-syscfg", "syscon";
- reg = <0x50020000 0x400>;
- clocks = <&rcc SYSCFG>;
- };
-
diff --git a/Documentation/devicetree/bindings/arm/sunxi/allwinner,sun4i-a10-mbus.yaml b/Documentation/devicetree/bindings/arm/sunxi/allwinner,sun4i-a10-mbus.yaml
new file mode 100644
index 000000000000..9370e64992dd
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/sunxi/allwinner,sun4i-a10-mbus.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/sunxi/allwinner,sun4i-a10-mbus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner Memory Bus (MBUS) controller
+
+maintainers:
+ - Chen-Yu Tsai <wens@csie.org>
+ - Maxime Ripard <mripard@kernel.org>
+
+description: |
+ The MBUS controller drives the MBUS that other devices in the SoC
+ will use to perform DMA. It also has a register interface that
+ allows to monitor and control the bandwidth and priorities for
+ masters on that bus.
+
+ Each device having to perform their DMA through the MBUS must have
+ the interconnects and interconnect-names properties set to the MBUS
+ controller and with "dma-mem" as the interconnect name.
+
+properties:
+ "#interconnect-cells":
+ const: 1
+ description:
+ The content of the cell is the MBUS ID.
+
+ compatible:
+ enum:
+ - allwinner,sun5i-a13-mbus
+ - allwinner,sun8i-h3-mbus
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ dma-ranges:
+ description:
+ See section 2.3.9 of the DeviceTree Specification.
+
+required:
+ - "#interconnect-cells"
+ - compatible
+ - reg
+ - clocks
+ - dma-ranges
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/sun5i-ccu.h>
+
+ mbus: dram-controller@1c01000 {
+ compatible = "allwinner,sun5i-a13-mbus";
+ reg = <0x01c01000 0x1000>;
+ clocks = <&ccu CLK_MBUS>;
+ dma-ranges = <0x00000000 0x40000000 0x20000000>;
+ #interconnect-cells = <1>;
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt b/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt
deleted file mode 100644
index 2005bb486705..000000000000
--- a/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-Allwinner Memory Bus (MBUS) controller
-
-The MBUS controller drives the MBUS that other devices in the SoC will
-use to perform DMA. It also has a register interface that allows to
-monitor and control the bandwidth and priorities for masters on that
-bus.
-
-Required properties:
- - compatible: Must be one of:
- - allwinner,sun5i-a13-mbus
- - allwinner,sun8i-h3-mbus
- - reg: Offset and length of the register set for the controller
- - clocks: phandle to the clock driving the controller
- - dma-ranges: See section 2.3.9 of the DeviceTree Specification
- - #interconnect-cells: Must be one, with the argument being the MBUS
- port ID
-
-Each device having to perform their DMA through the MBUS must have the
-interconnects and interconnect-names properties set to the MBUS
-controller and with "dma-mem" as the interconnect name.
-
-Example:
-
-mbus: dram-controller@1c01000 {
- compatible = "allwinner,sun5i-a13-mbus";
- reg = <0x01c01000 0x1000>;
- clocks = <&ccu CLK_MBUS>;
- dma-ranges = <0x00000000 0x40000000 0x20000000>;
- #interconnect-cells = <1>;
-};
-
-fe0: display-frontend@1e00000 {
- compatible = "allwinner,sun5i-a13-display-frontend";
- ...
- interconnects = <&mbus 19>;
- interconnect-names = "dma-mem";
-};