Device objects in Zephyr are currently placed into an array by linker
scripts, making it easy to iterate over all devices if the array
address and size can be obtained. This has applications in device
power management, but the existing API for this was available only
when that feature was enabled. It also uses a signed type to hold the
device count.
Provide a new API that is generally available, but marked as internal
since normally applications should not iterate over all devices. Mark
the PM API approach deprecated.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
Name all subsystem reference consistently with an '_api' postfix and
clean up naming and folder structure in some cases.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Add diagram showing the current system power management and the central
method of device power management.
The diagrams were made using draw.io and can be edit using draw.io.y
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
This commit brings power management subystem documentation up to date
with the implementation. The main changes since the last time the
documentation was updated include introduction of power managment
policies.
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
There exists SoCs, e.g. STM32L4, where one of the low power modes
reduces CPU frequency and supply voltage but does not stop the CPU. Such
power modes are currently not supported by Zephyr.
To facilitate adding support for such class of power modes in the future
and to ensure the naming convention makes it clear that the currently
supported power modes stop the CPU this commit renames Low Power States
to Slep States and updates the documentation.
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
Add framework for device Idle Power Management(IPM)
for suspending devices based on device idle. This will
help in saving power even while system(CPU) is active.
The framework uses device_set_power_state() API set the
device power state accordingly based on the usage count.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
The existing device_set_power_state() API works only in synchronous
mode and this is not desirable for devices(ex: Gyro) which take
longer time (few 100 mSec) to suspend/resume.
To support async mode, a new callback argument is added to the API.
The device drivers can asynchronously suspend/resume and call the
callback function upon completion of the async request.
This commit adds the missing callback parameter to all the drivers
to make it compliant with the new API.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
The phrase 'low power state' is often incorrectly used to indicate
'low power' or 'deep sleep' states. This commit fixes the ambiguities
by renaming 'low power state' to 'power state' where necessary.
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
CPU_LPS_n name used to indicate a low power state is cryptic and
incorrect. The low power states act on the whole SoC and not exclusively
on the CPU. This patch renames CPU_LPS_n states to LOW_POWER_n. Also
HAS_ pattern for Kconfig options is used in favor of a non standard
_SUPPORTED. Naming of deep sleep states was adjusted accordingly.
Following is a detailed list of string replacements used:
s/SYS_POWER_STATE_CPU_LPS_(\d)_SUPPORTED/HAS_STATE_LOW_POWER_$1/
s/SYS_POWER_STATE_CPU_LPS_(\d)/SYS_POWER_STATE_LOW_POWER_$1/
s/SYS_POWER_STATE_DEEP_SLEEP_(\d)_SUPPORTED/HAS_STATE_DEEP_SLEEP_$1/
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
This commit changes the names of SYS_POWER_DEEP_SLEEP* Kconfig
options in order to match SYS_POWER_LOW_POWER_STATE* naming
scheme.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
The SYS_POWER_LOW_POWER_STATE_SUPPORTED and SYS_POWER_LOW_POWER_STATE
suggests one low power state but these options control multiple
low power state. This commit uses plural in the names to indicate
that.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
Part of Power Management API was incorrecty documented under
"Power Management Hook Interface" section. This commit fixes
that problem by introducing "System Power Management APIs".
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
The power management framework used two different abstractions
to describe power states. The SYS_PM_* given coarse information
what kind of power state (low power or deep sleep) was used,
while the SYS_POWER_STATE_* abstraction provided information
about particular power mode.
This commit removes the SYS_PM_* abstraction as the same
information is already carried in SYS_POWER_STATE_*.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
Move guides and APIs into separate directories and cleanup naming
introducing index files rather than named section files.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
