michaelh/zephyr
1
0
Fork 0
Code Releases Activity

doc: guides: pm: device: remove API definitions

Browse source 
The API is already rendered automatically by breathe, so do not
duplicate it manually.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
This commit is contained in:
Gerard Marull-Paretas 2021-11-09 23:05:57 +01:00 • committed by Christopher Friedt
commit d1cb73a29c
1 changed files with 5 additions and 105 deletions
Download patch file Download diff file Expand all files Collapse all files

110
doc/guides/pm/device.rst
View file

@ -47,30 +47,12 @@ or idle.
Device Power Management States Device Power Management States
****************************** ******************************
The power management subsystem defines four device states.
These states are classified based on the degree of device context that gets lost
in those states, kind of operations done to save power, and the impact on the
device behavior due to the state transition. Device context includes device
registers, clocks, memory etc.
The three device power states: The power management subsystem defines device states in
:c:enum:`pm_device_state`. These states are classified based on the degree of
:code:`PM_DEVICE_STATE_ACTIVE` device context that gets lost in those states, kind of operations done to save
power, and the impact on the device behavior due to the state transition. Device
Normal operation of the device. All device context is retained. context includes device registers, clocks, memory etc.
:code:`PM_DEVICE_STATE_SUSPENDED`
The system is idle and entering a low power state. Most device context is
lost by the hardware. Device drivers must save and restore or reinitialize
any context lost by the hardware. Devices can check which state the system
is entering calling :c:func:`pm_power_state_next_get()` .
:code:`PM_DEVICE_STATE_OFF`
Power has been fully removed from the device. The device context is lost
when this state is entered. Need to reinitialize the device when powering
it back on.
Device Power Management Operations Device Power Management Operations
********************************** **********************************
@ -101,44 +83,6 @@ One of the macro parameters is the pointer to the PM action callback.
If the driver doesn't implement any power control operations, it can initialize If the driver doesn't implement any power control operations, it can initialize
the corresponding pointer with ``NULL``. the corresponding pointer with ``NULL``.
Device Power Management API
***************************
The SOC interface and application use these APIs to perform power management
operations on the devices.
Get Device List
===============
.. code-block:: c
size_t z_device_get_all_static(struct device const **device_list);
The Zephyr RTOS kernel internally maintains a list of all devices in the system.
The SOC interface uses this API to get the device list. The SOC interface can use the list to
identify the devices on which to execute power management operations.
.. note::
Ensure that the SOC interface does not alter the original list. Since the kernel
uses the original list, it must remain unchanged.
Device Set Power State
======================
.. code-block:: c
int pm_device_state_set(const struct device *dev, enum pm_device_state state);
Calls the device PM action callback with the provided state.
Device Get Power State
======================
.. code-block:: c
int pm_device_state_get(const struct device *dev, enum pm_device_state *state);
.. _pm-device-busy: .. _pm-device-busy:
Busy Status Indication Busy Status Indication
@ -155,50 +99,6 @@ When the :c:func:`pm_system_suspend()` is called, depending on the power state
returned by the policy manager, the system may suspend or put devices in low returned by the policy manager, the system may suspend or put devices in low
power if they are not marked as busy. power if they are not marked as busy.
Here are the APIs used to set, clear, and check the busy status of devices.
Indicate Busy Status API
========================
.. code-block:: c
void device_busy_set(const struct device *busy_dev);
Sets a bit corresponding to the device, in a data structure maintained by the
kernel, to indicate whether or not it is in the middle of a transaction.
Clear Busy Status API
=====================
.. code-block:: c
void device_busy_clear(const struct device *busy_dev);
Clears the bit corresponding to the device in a data structure
maintained by the kernel to indicate that the device is not in the middle of
a transaction.
Check Busy Status of Single Device API
======================================
.. code-block:: c
int device_busy_check(const struct device *chk_dev);
Checks whether a device is busy. The API returns 0 if the device
is not busy.
This API is used by the system power management.
Check Busy Status of All Devices API
====================================
.. code-block:: c
int device_any_busy_check(void);
Checks if any device is busy. The API returns 0 if no device in the system is busy.
Wakeup capability Wakeup capability
***************** *****************