Current API allowed to get notified when the maximum system latency
changes, however, a single callback was allowed. The design was intended
for SoC specific actions when latency changes. However, in some cases
drivers may also want to know the current maximum latency to perform
local actions if other parts of the system modify it.
This patch updates the API with a pair of subscribe/unsubscribe calls to
achieve such goal. Tests have been updated to show how the API can be
used.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
When new latency requirements are introduced/updated, the microseconds
value gets converted down to ticks. Ticks usually have a coarse
resolution compared to the microseconds scale. This is fine for making
PM state change decisions, however, when getting notified about latency
changes, we may want to know the real value in microseconds, even if the
system rounds to ticks internally. This patch stores the value in both
us and ticks (in ticks to cache the conversion, really), so that the
user will get notified with precise latency values.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
In order to bring consistency in-tree, migrate all subsystems code to
the new prefix <zephyr/...>. Note that the conversion has been scripted,
refer to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Add a new API that allows to register a callback that is called when the
maximum latency value changes. This can be used by SoC code to perform
actions based on certain latency values.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Add a new API that allows to configure maximum latency requirements.
When the policy manager computes the next state, it will check if the
state brings too much latency based on requirements. This can be useful,
for example, if a certain driver or the application want a system to
respond fast, since any low power state that brings too much latency
will not be used.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The state lock get/put calls should always be balanced: first call get
and then put. Add an assertion in case lock counter is about to go
negative, indicating a programming error.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The pm_constraint_* APIs were effectively used by the policy manager
only. This patch renames the API to the policy namespace and makes its
naming more explicit:
- pm_constraint_set -> pm_policy_state_lock_get()
- pm_constraint_release -> pm_policy_state_lock_put()
- pm_constraint_get -> pm_policy_state_lock_is_active()
The reason for these changes is that constraints can be of many types:
allow/disallow states, impose latency requirements, etc. The new naming
also makes explicit that the API calls will influence the PM policy
behavior.
All drivers and documentation have been updated accordingly.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
The policy file does not perform any logging, so just drop logging
include and declaration.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Move policy code one level up for simplicity, since there is a single
source file. Source file has been renamed to "policy.c" to make things
clear.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
