doc: power: General improvements (7e3e2093) · Commits · Wenxi XU / zephyr

doc/reference/power_management/index.rst

+35 −2

Original line number	Diff line number	Diff line
		@@ -93,6 +93,27 @@ have higher wake latencies. Following is a thorough list of available states:
		.. doxygenenumvalue:: PM_STATE_SOFT_OFF
		:project: Zephyr

		.. _pm_constraints:

		Power States Constraint
		=======================

		The power management subsystem allows different Zephyr components and
		applications to set constraints on various power states preventing the
		system to go these states. This can be used by devices when executing
		tasks in background to avoid the system to go to state where it would
		lose context. Constraints can be set, released and checked using the
		follow APIs:

		.. doxygenfunction:: pm_constraint_set
		:project: Zephyr

		.. doxygenfunction:: pm_constraint_release
		:project: Zephyr

		.. doxygenfunction:: pm_constraint_get
		:project: Zephyr

		Power Management Policies
		=========================

		@@ -102,12 +123,20 @@ The power management subsystem supports the following power management policies:
		* Application
		* Dummy

		The policy manager is responsible to inform the power subsystem which
		power state the system should go based on states available in the
		platform and possible runtime :ref:`constraints<pm_constraints>`

		Information about states can be get from device tree, see
		:zephyr_file:`dts/bindings/power/state.yaml`.

		Residency
		---------

		The power management system enters the power state which offers the highest
		power savings, and with a minimum residency value (defined by the respective
		Kconfig option) less than or equal to the scheduled system idle time duration.
		power savings, and with a minimum residency value (in device tree, see
		:zephyr_file:`dts/bindings/power/state.yaml`) less than or equal to
		the scheduled system idle time duration.

		Application
		-----------
		@@ -119,6 +148,10 @@ the following function.

		struct pm_state_info pm_policy_next_state(int32_t ticks);

		In this policy the application is free to decide which power state the
		system should go based on the remaining time for the next scheduled
		timeout.

		Dummy
		-----

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