In the multiple PM domain case we need platform code to specify the index
of the corresponding required OPP in DT for a device, which is what
*_opp_attach_genpd() is there to help us with.

However, attaching a device to its PM domains is in general better done
with dev_pm_domain_attach_list(). To avoid having two different ways to
manage this and to prepare for the removal of *_opp_attach_genpd(), let's
extend dev_pm_domain_attach|detach_list() to manage the required OPPs too.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20241002122232.194245-5-ulf.hansson@linaro.org

The dev_pm_domain_attach|detach_list() functions are not resource managed,
hence they should not use devm_* helpers to manage allocation/freeing of
data. Let's fix this by converting to the traditional alloc/free functions.

Fixes: 161e16a5e50a ("PM: domains: Add helper functions to attach/detach multiple PM domains")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20241002122232.194245-3-ulf.hansson@linaro.org

Add the devres-enabled version of dev_pm_domain_attach|detach_list.
If client drivers use devm_pm_domain_attach_list() to attach the PM domains,
devm_pm_domain_detach_list() will be invoked implicitly during remove phase.

Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Link: https://lore.kernel.org/r/1724063350-11993-2-git-send-email-quic_dikshita@quicinc.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Attaching/detaching of a device to multiple PM domains has started to
become a common operation for many drivers, typically during ->probe() and
->remove(). In most cases, this has lead to lots of boilerplate code in the
drivers.

To fixup up the situation, let's introduce a pair of helper functions,
dev_pm_domain_attach|detach_list(), that driver can use instead of the
open-coding. Note that, it seems reasonable to limit the support for these
helpers to DT based platforms, at it's the only valid use case for now.

Suggested-by: Daniel Baluta <daniel.baluta@nxp.com>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Tested-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20240130123951.236243-2-ulf.hansson@linaro.org

The generic PM domain is currently the only PM domain variant that supports
performance scaling. To allow performance scaling to be supported through a
common interface, let's add an optional callback ->set_performance_state(),
in the struct dev_pm_domain.

Moreover, let's add a function, dev_pm_domain_set_performance_state(), that
may be called by consumers to request a new performance state for a device
through its PM domain.

Note that, in most cases it's preferred that a consumer use the OPP library
to request a new performance state for its device. Although, this requires
some additional changes to be supported, which are being implemented from
subsequent changes.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Mention all domain attach menthods which dev_pm_domain_detach()
reverses.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For a subsystem/driver that either doesn't support runtime PM or makes use
of pm_runtime_set_active() during ->probe(), may try to access its device
when probing, even if it may not be fully powered on from the PM domain's
point of view. This may be the case when the used PM domain is a genpd
provider, that implements genpd's ->start|stop() device callbacks.

There are cases where the subsystem/driver managed to avoid the above
problem, simply by calling pm_runtime_enable() and pm_runtime_get_sync()
during ->probe(). However, this approach comes with a drawback, especially
if the subsystem/driver implements a ->runtime_resume() callback.

More precisely, the subsystem/driver then needs to use a device flag, which
is checked in its ->runtime_resume() callback, as to avoid powering on its
resources the first time the callback is invoked. This is needed because
the subsystem/driver has already powered on the resources for the device,
during ->probe() and before it called pm_runtime_get_sync().

In a way to avoid this boilerplate code and the inefficient check for "if
(first_time_suspend)" in the ->runtime_resume() callback for these
subsystems/drivers, let's introduce and export a dev_pm_domain_start()
function, that may be called during ->probe() instead.

Moreover, let the dev_pm_domain_start() invoke an optional ->start()
callback, added to the struct dev_pm_domain, as to allow a PM domain
specific implementation.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There were a few files in the driver core power code that did not have
SPDX identifiers on them, so fix that up.  At the same time, remove the
"free form" text that specified the license of the file, as that is
impossible for any tool to properly parse.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As of the patch ("PM / Domains: Mark "name" const in
genpd_dev_pm_attach_by_name()") it's clear that the name in
dev_pm_domain_attach_by_name() can be const.  Mark it as so.  This
allows drivers to pass in a name that was declared "const" in a
driver.

Fixes: 27dceb81f445 ("PM / Domains: Introduce dev_pm_domain_attach_by_name()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For the multiple PM domain case, let's introduce a new API called
dev_pm_domain_attach_by_name(). This allows a consumer driver to associate
its device with one of its PM domains, by using a name based lookup.

Do note that, currently it's only genpd that supports multiple PM domains
per device, but dev_pm_domain_attach_by_name() can easily by extended to
cover other PM domain types, if/when needed.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>