Power Management States

Data Structures
struct	pm_state_info

Macros
#define	PM_STATE_INFO_DT_ITEM_BY_IDX(node_id, i)
	Construct a pm_state_info from 'cpu-power-states' property at index 'i'. More...
#define	PM_STATE_DT_ITEMS_LEN(node_id)    DT_PROP_LEN_OR(node_id, cpu_power_states, 0)
	Length of 'cpu-power-states' property. More...
#define	PM_STATE_INFO_DT_ITEMS_LISTIFY_FUNC(child, node_id)    PM_STATE_INFO_DT_ITEM_BY_IDX(node_id, child)
	Macro function to construct enum pm_state item in UTIL_LISTIFY extension. More...
#define	PM_STATE_INFO_DT_ITEMS_LIST(node_id)
	Macro function to construct a list of 'pm_state_info' items by UTIL_LISTIFY func. More...
#define	PM_STATE_DT_ITEM_BY_IDX(node_id, i)
	Construct a pm_state enum from 'cpu-power-states' property at index 'i'. More...
#define	PM_STATE_DT_ITEMS_LISTIFY_FUNC(child, node_id)    PM_STATE_DT_ITEM_BY_IDX(node_id, child)
	Macro function to construct enum pm_state item in UTIL_LISTIFY extension. More...
#define	PM_STATE_DT_ITEMS_LIST(node_id)
	Macro function to construct a list of enum pm_state items by UTIL_LISTIFY func. More...

Enumerations
enum	pm_state {   PM_STATE_ACTIVE , PM_STATE_RUNTIME_IDLE , PM_STATE_SUSPEND_TO_IDLE , PM_STATE_STANDBY ,   PM_STATE_SUSPEND_TO_RAM , PM_STATE_SUSPEND_TO_DISK , PM_STATE_SOFT_OFF }

Detailed Description

Macro Definition Documentation

PM_STATE_DT_ITEM_BY_IDX

#define PM_STATE_DT_ITEM_BY_IDX	(		node_id,
			i
	)

#include <include/pm/state.h>

Value:

        DT_ENUM_IDX(DT_PHANDLE_BY_IDX(node_id,                  \
                      cpu_power_states, i), power_state_name),

Construct a pm_state enum from 'cpu-power-states' property at index 'i'.

Parameters

node_id	A node identifier with compatible zephyr,power-state
i	index into cpu-power-states property

Returns

pm_state item from 'cpu-power-states' property at index 'i'

PM_STATE_DT_ITEMS_LEN

#define PM_STATE_DT_ITEMS_LEN

(

node_id

)

DT_PROP_LEN_OR(node_id, cpu_power_states, 0)

#include <include/pm/state.h>

Length of 'cpu-power-states' property.

Parameters

node_id

A node identifier with compatible zephyr,power-state

Returns

length of 'cpu-power-states' property

PM_STATE_DT_ITEMS_LIST

#define PM_STATE_DT_ITEMS_LIST

(

node_id

)

#include <include/pm/state.h>

Value:

        {           \
        UTIL_LISTIFY(PM_STATE_DT_ITEMS_LEN(node_id),\
                     PM_STATE_DT_ITEMS_LISTIFY_FUNC,\
                     node_id)                       \
        }

Macro function to construct a list of enum pm_state items by UTIL_LISTIFY func.

Example devicetree fragment: cpus { ... cpu0: cpu@0 { device_type = "cpu"; ... cpu-power-states = <&state0 &state1>; }; };

... state0: state0 { compatible = "zephyr,power-state"; power-state-name = "suspend-to-idle"; min-residency-us = <10000>; exit-latency-us = <100>; };

state1: state1 { compatible = "zephyr,power-state"; power-state-name = "suspend-to-ram"; min-residency-us = <50000>; exit-latency-us = <500>; };

Example usage: * const enum pm_state states[] = PM_STATE_DT_ITEMS_LIST(DT_NODELABEL(cpu0));

Parameters

node_id

A node identifier with compatible zephyr,power-state

Returns

an array of enum pm_state items.

PM_STATE_DT_ITEMS_LISTIFY_FUNC

#define PM_STATE_DT_ITEMS_LISTIFY_FUNC	(		child,
			node_id
	)		PM_STATE_DT_ITEM_BY_IDX(node_id, child)

#include <include/pm/state.h>

Macro function to construct enum pm_state item in UTIL_LISTIFY extension.

Parameters

child	child index in UTIL_LISTIFY extension.
node_id	A node identifier with compatible zephyr,power-state

Returns

macro function to construct a pm_state enum

PM_STATE_INFO_DT_ITEM_BY_IDX

#define PM_STATE_INFO_DT_ITEM_BY_IDX	(		node_id,
			i
	)

#include <include/pm/state.h>

Value:

        {                                                           \
                .state = DT_ENUM_IDX(DT_PHANDLE_BY_IDX(node_id, \
                        cpu_power_states, i), power_state_name),    \
                .substate_id = DT_PROP_BY_PHANDLE_IDX_OR(node_id, \
                        cpu_power_states, i, substate_id, 0),   \
                .min_residency_us = DT_PROP_BY_PHANDLE_IDX_OR(node_id, \
                                cpu_power_states, i, min_residency_us, 0),\
                .exit_latency_us = DT_PROP_BY_PHANDLE_IDX_OR(node_id, \
                                cpu_power_states, i, exit_latency_us, 0),\
        },

Construct a pm_state_info from 'cpu-power-states' property at index 'i'.

Parameters

node_id	A node identifier with compatible zephyr,power-state
i	index into cpu-power-states property

Returns

pm_state_info item from 'cpu-power-states' property at index 'i'

PM_STATE_INFO_DT_ITEMS_LIST

#define PM_STATE_INFO_DT_ITEMS_LIST

(

node_id

)

#include <include/pm/state.h>

Value:

        {         \
        UTIL_LISTIFY(PM_STATE_DT_ITEMS_LEN(node_id),   \
                     PM_STATE_INFO_DT_ITEMS_LISTIFY_FUNC,\
                     node_id)                          \
        }

Macro function to construct a list of 'pm_state_info' items by UTIL_LISTIFY func.

Example devicetree fragment: cpus { ... cpu0: cpu@0 { device_type = "cpu"; ... cpu-power-states = <&state0 &state1>; }; };

... power-states { state0: state0 { compatible = "zephyr,power-state"; power-state-name = "suspend-to-idle"; min-residency-us = <10000>; exit-latency-us = <100>; };

state1: state1 { compatible = "zephyr,power-state"; power-state-name = "suspend-to-ram"; min-residency-us = <50000>; exit-latency-us = <500>; }; };

Example usage: * const struct pm_state_info states[] = PM_STATE_INFO_DT_ITEMS_LIST(DT_NODELABEL(cpu0));

Parameters

node_id

A node identifier with compatible zephyr,power-state

Returns

an array of struct pm_state_info.

PM_STATE_INFO_DT_ITEMS_LISTIFY_FUNC

#define PM_STATE_INFO_DT_ITEMS_LISTIFY_FUNC	(		child,
			node_id
	)		PM_STATE_INFO_DT_ITEM_BY_IDX(node_id, child)

#include <include/pm/state.h>

Macro function to construct enum pm_state item in UTIL_LISTIFY extension.

Parameters

child	child index in UTIL_LISTIFY extension.
node_id	A node identifier with compatible zephyr,power-state

Returns

macro function to construct a pm_state_info

Enumeration Type Documentation

pm_state

enum pm_state

#include <include/pm/state.h>

Power management state

Enumerator
PM_STATE_ACTIVE	Runtime active state. The system is fully powered and active. Note This state is correlated with ACPI G0/S0 state
PM_STATE_RUNTIME_IDLE	Runtime idle state. Runtime idle is a system sleep state in which all of the cores enter deepest possible idle state and wait for interrupts, no requirements for the devices, leaving them at the states where they are. Note This state is correlated with ACPI S0ix state
PM_STATE_SUSPEND_TO_IDLE	Suspend to idle state. The system goes through a normal platform suspend where it puts all of the cores in deepest possible idle state and may puts peripherals into low-power states. No operating state is lost (ie. the cpu core does not lose execution context), so the system can go back to where it left off easily enough. Note This state is correlated with ACPI S1 state
PM_STATE_STANDBY	Standby state. In addition to putting peripherals into low-power states all non-boot CPUs are powered off. It should allow more energy to be saved relative to suspend to idle, but the resume latency will generally be greater than for that state. But it should be the same state with suspend to idle state on uniprocesser system. Note This state is correlated with ACPI S2 state
PM_STATE_SUSPEND_TO_RAM	Suspend to ram state. This state offers significant energy savings by powering off as much of the system as possible, where memory should be placed into the self-refresh mode to retain its contents. The state of devices and CPUs is saved and held in memory, and it may require some boot- strapping code in ROM to resume the system from it. Note This state is correlated with ACPI S3 state
PM_STATE_SUSPEND_TO_DISK	Suspend to disk state. This state offers significant energy savings by powering off as much of the system as possible, including the memory. The contents of memory are written to disk or other non-volatile storage, and on resume it's read back into memory with the help of boot-strapping code, restores the system to the same point of execution where it went to suspend to disk. Note This state is correlated with ACPI S4 state
PM_STATE_SOFT_OFF	Soft off state. This state consumes a minimal amount of power and requires a large latency in order to return to runtime active state. The contents of system(CPU and memory) will not be preserved, so the system will be restarted as if from initial power-up and kernel boot. Note This state is correlated with ACPI G2/S5 state