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path: root/drivers/cpuidle/cpuidle-psci-domain.c
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2020-01-02cpuidle: psci: Add support for PM domains by using genpdUlf Hansson
When the hierarchical CPU topology layout is used in DT and the PSCI OSI mode is supported by the PSCI FW, let's initialize a corresponding PM domain topology by using genpd. This enables a CPU and a group of CPUs, when attached to the topology, to be power-managed accordingly. To trigger the attempt to initialize the genpd data structures let's use a subsys_initcall, which should be early enough to allow CPUs, but also other devices to be attached. The initialization consists of parsing the PSCI OF node for the topology and the "domain idle states" DT bindings. In case the idle states are compatible with "domain-idle-state", the initialized genpd becomes responsible of selecting an idle state for the PM domain, via assigning it a genpd governor. Note that, a successful initialization of the genpd data structures, is followed by a call to psci_set_osi_mode(), as to try to enable the OSI mode in the PSCI FW. In case this fails, we fall back into a degraded mode rather than bailing out and returning error codes. Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Add a helper to attach a CPU to its PM domainUlf Hansson
Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a CPU number as an in-parameter and tries to attach the CPU's struct device to its corresponding PM domain. Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to specify "psci" as the "name" of the PM domain to attach to. Additionally, let's also prepare the attached device to be power managed via runtime PM. Note that, the implementation of the new helper function is in a new separate c-file, which may seems a bit too much at this point. However, subsequent changes that implements the remaining part of the PM domain support for cpuidle-psci, helps to justify this split. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>