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Commit fbaae361 authored by Lina Iyer's avatar Lina Iyer Committed by Maulik Shah
Browse files

dt-bindings: msm: add PM drivers device bindings 

Add system_pm, lpm_levels and RPMH master stats device bindings for
power drivers.

Change-Id: I31cff3d94a7e3649cc720e0ca02e34bdfd65b3f3
parent 6afacf98

bindings/arm/msm/lpm-levels.txt

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* Low Power Management Levels



The application processor in MSM can do a variety of C-States for low power

management. The LPM module performs the System low power modes based on

the latency/residency information of the individual CPUs and clusters.



LPM-levels defines a hierarchy of low power modes that a cluster and

clusters/cpus within that cluster can enter. The bottom hierarchy level

represents the low power modes that a CPU can enter. The CPU low power nodes

are associated with a cluster that defines the low power modes that a cluster

can enter. For system involving a hierarchy of clusters, the cluster low power

modes can be contained within another cluster.



[Top Level Node]

Required properties:



- compatible: "qcom,lpm-levels"



[Node bindings for qcom,pm-cluster]

 Required properties:

	- reg - The numeric cluster id

	- label: Identifies the cluster name. The name is used when reporting

	the stats for each low power mode.

	- qcom,psci-mode-shift: The property is used to determine with bit

	location of the cluster mode in the composite state ID used to define

	cluster low power modes in PSCI.

	- qcom,psci-mode-mask: The property is used to determine with bit

	mask of the cluster mode in the composite state ID used to define

	cluster low power modes in PSCI.



Optional properties:

	- qcom,disable-prediction: This property is used to indicate the LPM

	governor will not use LPM prediction for this cluster.

	- qcom,clstr-tmr-add: This property is used as correction timer for

	wrong prediction by lpm prediction algorithm for cluster predictions.

	This value should be between 100 to 1500. Higher values would mean

	longer time staying in shallower state before waking up to select a

	deeper state in case of wrong prediction.

	qcom,pm-cluster contains qcom,pm-cluster-level nodes which identify

	the various low power modes that the cluster can enter. The

	qcom,pm-cluster node should also include another cluster node or a cpu

	node that defines their respective low power modes.



[Node bindings for qcom,pm-cluster-level]

 Required properties:

	- compatible: must be "arm,idle-state"

	- reg: The numeric cpu level id

	- idle-state-name: Name to identify the low power mode in stats

	- qcom,psci-cpu-mode: ID to be passed into PSCI firmware.

	- arm,psci-suspend-param: State ID for the CPU idle state

	- entry-latency-us: The latency to enter LPM level, in uSec

	- exit-latency-us: The latency to exit LPM level, in uSec

	- min-residency-us: The minimum residency value from which entering

	to low power mode is beneficial, in uSec

	- qcom,min-child-idx: The minimum level that a child CPU should be in

	before this level can be chosen. This property is required for all

        non-default level.



 Optional properties:

	- qcom,notify-rpm: When set, the driver configures the sleep and wake

	sets. It also configures the next wakeup time for APPS.

	- qcom,is-reset: This boolean property tells whether cluster level need

	power management notifications to be sent out or not for the drivers to

	prepare for cluster collapse.

	- qcom,reset-level: This property is used to determine in this

	low power mode only control logic power collapse happens or memory

	logic power collapse aswell happens or retention state.

	The accepted values for this property are:

		"LPM_RESET_LVL_NONE" - No power collapse

		"LPM_RESET_LVL_RET"  - Retention state

		"LPM_RESET_LVL_GDHS" - Only control logic power collapse (GDHS)

		"LPM_RESET_LVL_PC" - Control logic and memory logic

					power collapse (PC)



[Node bindings for qcom,pm-cpu]

qcom,pm-cpu contains the low power modes that a cpu could enter and the CPUs

that share the parameters.It contains the following properties.

	- qcom,cpu: List of CPU phandles to identify the CPUs associated with

	this cluster.

	- qcom,psci-mode-shift: Same as cluster level fields.

	- qcom,psci-mode-mask: Same as cluster level fields.

	- qcom,pm-cpu-levels: The different low power modes that a CPU could

	enter. The following section explains the required properties of this

	node.



Optional properties:

	- qcom,disable-prediction: This property is used to indicate the

	LPM governor is to disable sleep prediction to this cpu.

	- qcom,ref-stddev: This property is used as reference standard deviation

	in lpm prediction algorithm. This value should be between 100 to 1000.

	Higher value would result in more predictions and thereby resulting in

	shallower low power modes.

	- qcom,tmr-add: This property is used as correction timer for wrong

	prediction by lpm prediction algorithm. This value should be between

	100 to 1500. Higher values would mean longer time staying in shallower

	state before waking up to select a deeper state in case of wrong prediction.

	- qcom,ref-premature-cnt: This property is used as reference premature

	count to predict next sleep state by the prediction algorithm. This value

	should be between 1 to 5. Higher value for this parameter would result in

	less predictions to disallow deeper low power modes.



[Node bindings for qcom,pm-cpu-levels]

 Required properties:

	- compatible: must be "arm,idle-state"

	- reg: The numeric cpu level id

	- idle-state-name: Name to identify the low power mode in stats

	- qcom,psci-cpu-mode: ID to be passed into PSCI firmware.

	- arm,psci-suspend-param: State ID for the CPU idle state

	- entry-latency-us: The latency to enter LPM level, in uSec

	- exit-latency-us: The latency to exit LPM level, in uSec

	- min-residency-us: The minimum residency value from which entering

	to low power mode is beneficial, in uSec



 Optional properties:

	- qcom,is-reset: This boolean property maps to "power state" bit in PSCI

	state_id configuration. This property will tell whether CPU get reset for

	a particular LPM or not. This property is also used to notify the drivers

	in case of cpu reset.

	- qcom,use-broadcast-timer: Indicates that the timer gets reset during

	power collapse and the cpu relies on Broadcast timer for scheduled wakeups.

	Required only for states where the CPUs internal timer state is lost.



[Example dts]



	qcom,lpm-levels {

		compatible = "qcom,lpm-levels";

		#address-cells = <1>;

		#size-cells = <0>;



		qcom,pm-cluster@0 {

			reg = <0>;

			#address-cells = <1>;

			#size-cells = <0>;

			idle-state-name = "L3";

			qcom,clstr-tmr-add = <1000>;

			qcom,psci-mode-shift = <4>;

			qcom,psci-mode-mask = <0xfff>;



			CLUSTER_WFI: qcom,pm-cluster-level@0 { /* D1 */

				reg = <0>;

				compatible = "arm,idle-state";

				idle-state-name = "l3-wfi";

				entry-latency-us = <48>;

				exit-latency-us = <51>;

				min-residency-us = <99>;

				arm,psci-suspend-param = <0x10>;

				qcom,psci-mode = <0x1>;

			};



			CLUSTER_OFF: qcom,pm-cluster-level@1 { /* LLCC off, AOSS sleep */

				reg = <1>;

				compatible = "arm,idle-state";

				idle-state-name = "llcc-off";

				entry-latency-us = <3263>;

				exit-latency-us = <6562>;

				min-residency-us = <9987>;

				arm,psci-suspend-param = <0xc240>;

				qcom,psci-mode = <0xc24>;

				qcom,is-reset;

				qcom,notify-rpm;

				qcom,min-child-idx = <1>;

			};



			qcom,pm-cpu@0 {

				reg = <0>;

				#address-cells = <1>;

				#size-cells = <0>;

				qcom,psci-mode-shift = <0>;

				qcom,psci-mode-mask = <0xf>;

				qcom,ref-stddev = <500>;

				qcom,tmr-add = <1000>;

				qcom,ref-premature-cnt = <1>;

				qcom,cpu = <&CPU0 &CPU1 &CPU2 &CPU3>;



				SLVR_WFI: qcom,pm-cpu-level@0 { /* C1 */

					reg = <0>;

					compatible = "arm,idle-state";

					idle-state-name = "wfi";

					entry-latency-us = <57>;

					exit-latency-us = <43>;

					min-residency-us = <100>;

					arm,psci-suspend-param = <0x1>;

					qcom,psci-cpu-mode = <0x1>;

				};



				SLVR_RAIL_OFF: qcom,pm-cpu-level@1 {  /* C4 */

					reg = <1>;

					compatible = "arm,idle-state";

					idle-state-name = "rail-pc";

					entry-latency-us = <360>;

					exit-latency-us = <531>;

					min-residency-us = <3934>;

					arm,psci-suspend-param = <0x40000004>;

					local-timer-stop;

					qcom,psci-cpu-mode = <0x4>;

					qcom,is-reset;

					qcom,use-broadcast-timer;

				};

			};



			qcom,pm-cpu@1 {

				reg = <1>;

				#address-cells = <1>;

				#size-cells = <0>;

				qcom,psci-mode-shift = <0>;

				qcom,psci-mode-mask = <0xf>;

				qcom,cpu = <&CPU4 &CPU5 &CPU6 &CPU7>;



				GOLD_WFI: qcom,pm-cpu-level@0 { /* C1 */

					reg = <0>;

					compatible = "arm,idle-state";

					idle-state-name = "wfi";

					entry-latency-us = <57>;

					exit-latency-us = <43>;

					min-residency-us = <83>;

					arm,psci-suspend-param = <0x1>;

					qcom,psci-cpu-mode = <0x1>;

				};



				GOLD_RAIL_OFF: qcom,pm-cpu-level@1 {  /* C4 */

					reg = <1>;

					compatible = "arm,idle-state";

					idle-state-name = "rail-pc";

					entry-latency-us = <702>;

					exit-latency-us = <1061>;

					min-residency-us = <4488>;

					arm,psci-suspend-param = <0x40000004>;

					local-timer-stop;

					qcom,psci-cpu-mode = <0x4>;

					qcom,is-reset;

					qcom,use-broadcast-timer;

				};

			};

		};

	};

bindings/arm/msm/rpmh-master-stats.txt

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* RPMH Master Stats



Differet Subsystems maintains master data in SMEM.

It tells about the individual masters information at any given

time like "system sleep counts", "system sleep last entered at"

and "system sleep accumulated duration" etc. These stats can be

displayed using the sysfs interface.

To achieve this, device tree node has been added.



Additionally, RPMH master stats also maintains application processor's

master stats. It uses profiling units to calculate power down and power

up stats.



The required properties for rpmh-master-stats are:



- compatible:

	Usage: required

	Value type: <string>

	Definition: Should be "qcom,rpmh-master-stats-v1".



- reg:

	Usage: required

	Value type: <prop-encoded-array>

	Definition: Specifies physical address of start of profiling unit.



Example:



qcom,rpmh-master-stats {

	compatible = "qcom,rpmh-master-stats";

	reg = <0xb221200 0x60>;

};

bindings/arm/msm/system-pm.txt

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SYSTEM PM



System PM device is a virtual device that handles all CPU subsystem low power

mode activties. When entering core shutdown, resource state that were

requested

from the processor may be relinquished and set to idle and restored when the

cores are brought out of sleep.



PROPERTIES



- compatible:

	Usage: required

	Value type: <string>

	Definition: must be "qcom,system-pm".



EXAMPLE



	system_pm {

		compatible = "qcom,system-pm";

	};