Currently a genpd only handles the performance state requirements from
the devices under its control. This commit extends that to also handle
the performance state requirement(s) put on the master genpd by its
sub-domains. There is a separate value required for each master that
the genpd has and so a new field is added to the struct gpd_link
(link->performance_state), which represents the link between a genpd and
its master. The struct gpd_link also got another field
prev_performance_state, which is used by genpd core as a temporary
variable during transitions.

On a call to dev_pm_genpd_set_performance_state(), the genpd core first
updates the performance state of the masters of the device's genpd and
then updates the performance state of the genpd. The masters do the same
and propagate performance state updates to their masters before updating
their own. The performance state transition from genpd to its master is
done with the help of dev_pm_opp_xlate_performance_state(), which looks
at the OPP tables of both the domains to translate the state.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

dev_pm_genpd_set_performance_state() will be required to call
dev_pm_opp_xlate_performance_state() going forward to translate from
performance state of a sub-domain to performance state of its master.
And dev_pm_opp_xlate_performance_state() needs pointers to the OPP
tables of both genpd and its master.

Lets fetch and save them while the OPP tables are added. Fetching the
OPP tables should never fail as we just added the OPP tables and so add
a WARN_ON() for such a bug instead of full error paths.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The OPP core already has the performance state values for each of the
genpd's OPPs and there is no need to call the genpd callback again to
get the performance state for the case where the end device doesn't have
an OPP table and has the "required-opps" property directly in its node.

This commit renames of_genpd_opp_to_performance_state() as
of_get_required_opp_performance_state() and moves it to the OPP core, as
it is all about OPP stuff now.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The OPP core currently stores the performance state in the consumer
device's OPP table, but that is going to change going forward and
performance state will rather be set directly in the genpd's OPP table.

For that we need to get the performance state for genpd's device
structure (genpd->dev) instead of the consumer device's structure. Add a
new helper to do that.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The current documented description of the GENPD_FLAG_* flags, are too
simplified, so let's extend them.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael 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: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

For the multiple PM domain case, let's introduce a new function called
genpd_dev_pm_attach_by_name(). This allows a device to be associated with
its PM domain through genpd, by using a name based lookup.

Note that, genpd_dev_pm_attach_by_name() shall only be called by the driver
core / PM core, similar to how the existing dev_pm_domain_attach_by_id()
makes use of genpd_dev_pm_attach_by_id(). However, this is implemented by
following changes on top.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The DT node passed here isn't necessarily an OPP node, as this routine
can also be used for cases where the "required-opps" property is present
directly in the device's node. Rename it.

This also removes a stale comment.
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

of_genpd_opp_to_performance_state() should return 0 for errors, but the
dummy routine isn't doing that. Fix it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The existing dev_pm_domain_attach() function, allows a single PM domain to
be attached per device. To be able to support devices that are partitioned
across multiple PM domains, let's introduce a new interface,
dev_pm_domain_attach_by_id().

The dev_pm_domain_attach_by_id() returns a new allocated struct device with
the corresponding attached PM domain. This enables for example a driver to
operate on the new device from a power management point of view. The driver
may then also benefit from using the received device, to set up so called
device-links towards its original device. Depending on the situation, these
links may then be dynamically changed.

The new interface is typically called by drivers during their probe phase,
in case they manages devices which uses multiple PM domains. If that is the
case, the driver also becomes responsible of managing the detaching of the
PM domains, which typically should be done at the remove phase. Detaching
is done by calling the existing dev_pm_domain_detach() function and for
each of the received devices from dev_pm_domain_attach_by_id().

Note, currently its only genpd that supports multiple PM domains per
device, but dev_pm_domain_attach_by_id() can easily by extended to cover
other PM domain types, if/when needed.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Tested-by: NJon Hunter <jonathanh@nvidia.com>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To support devices being partitioned across multiple PM domains, let's
begin with extending genpd to cope with these kind of configurations.

Therefore, add a new exported function genpd_dev_pm_attach_by_id(), which
is similar to the existing genpd_dev_pm_attach(), but with the difference
that it allows its callers to provide an index to the PM domain that it
wants to attach.

Note that, genpd_dev_pm_attach_by_id() shall only be called by the driver
core / PM core, similar to how the existing dev_pm_domain_attach() makes
use of genpd_dev_pm_attach(). However, this is implemented by following
changes on top.

Because, only one PM domain can be attached per device, genpd needs to
create a virtual device that it can attach/detach instead. More precisely,
let the new function genpd_dev_pm_attach_by_id() register a virtual struct
device via calling device_register(). Then let it attach this device to the
corresponding PM domain, rather than the one that is provided by the
caller. The actual attaching is done via re-using the existing genpd OF
functions.

At successful attachment, genpd_dev_pm_attach_by_id() returns the created
virtual device, which allows the caller to operate on it to deal with power
management. Following changes on top, provides more details in this
regards.

To deal with detaching of a PM domain for the multiple PM domains case,
let's also extend the existing genpd_dev_pm_detach() function, to cover the
cleanup of the created virtual device, via make it call device_unregister()
on it. In this way, there is no need to introduce a new function to deal
with detach for the multiple PM domain case, but instead the existing one
is re-used.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Tested-by: NJon Hunter <jonathanh@nvidia.com>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no need to pass a genpd struct to pm_genpd_remove_device(), as we
already have the information about the PM domain (genpd) through the device
structure.

Additionally, we don't allow to remove a PM domain from a device, other
than the one it may have assigned to it, so really it does not make sense
to have a separate in-param for it.

For these reason, drop it and update the current only call to
pm_genpd_remove_device() from amdgpu_acp.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are still a few non-DT existing users of genpd, however neither of
them uses __pm_genpd_add_device(), hence let's drop it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Using "extern" to declare a function in a public header file is somewhat
pointless, but also doesn't hurt. However, to make all the function
declarations in pm_domain.h to be consistent, let's drop the use of
"extern".
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The callers of dev_pm_domain_attach() currently checks the returned error
code for -EPROBE_DEFER and needs to ignore other error codes. This is an
unnecessary limitation, which also leads to a rather strange behaviour in
the error path.

Address this limitation, by changing the return codes from
acpi_dev_pm_attach() and genpd_dev_pm_attach(). More precisely, let them
return 0, when no PM domain is needed for the device and then return 1, in
case the device was successfully attached to its PM domain. In this way,
dev_pm_domain_attach(), gets a better understanding of what happens in the
attach attempts and also allowing its caller to better act on real errors
codes.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This implements of_genpd_opp_to_performance_state() which can be used
from the device drivers or the OPP core to find the performance state
encoded in the "required-opps" property of a node. Normally this would
be called only once for each OPP of the device for which the OPP table
of the device is getting generated.

Different platforms may encode the performance state differently using
the OPP table (they may simply return value of opp-hz or opp-microvolt,
or apply some algorithm on top of those values) and so a new callback
->opp_to_performance_state() is implemented to allow platform specific
drivers to convert the power domain OPP to a performance state value.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>

The power-domain core would be using the OPP core going forward and the
OPP core has the basic requirement of a device structure for its working.

Add a struct device to the genpd structure. This doesn't register the
device with device core as the "dev" pointer is mostly used by the OPP
core as a cookie for now and registering the device is not mandatory.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>

There are no more users left of the gpd_dev_ops.active_wakeup()
callback.  All have been converted to GENPD_FLAG_ACTIVE_WAKEUP.
Hence remove the callback.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is quite common for PM Domains to require slave devices to be kept
active during system suspend if they are to be used as wakeup sources.
To enable this, currently each PM Domain or driver has to provide its
own gpd_dev_ops.active_wakeup() callback.

Introduce a new flag GENPD_FLAG_ACTIVE_WAKEUP to consolidate this.
If specified, all slave devices configured as wakeup sources will be
kept active during system suspend.

PM Domains that need more fine-grained controls, based on the slave
device, can still provide their own callbacks, as before.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some platforms have the capability to configure the performance state of
PM domains. This patch enhances the genpd core to support such
platforms.

The performance levels (within the genpd core) are identified by
positive integer values, a lower value represents lower performance
state.

This patch adds a new genpd API, which is called by user drivers (like
OPP framework):

- int dev_pm_genpd_set_performance_state(struct device *dev,
					 unsigned int state);

  This updates the performance state constraint of the device on its PM
  domain. On success, the genpd will have its performance state set to a
  value which is >= "state" passed to this routine. The genpd core calls
  the genpd->set_performance_state() callback, if implemented,
  else -ENODEV is returned to the caller.

The PM domain drivers need to implement the following callback if they
want to support performance states.

- int (*set_performance_state)(struct generic_pm_domain *genpd,
			       unsigned int state);

  This is called internally by the genpd core on several occasions. The
  genpd core passes the genpd pointer and the aggregate of the
  performance states of the devices supported by that genpd to this
  callback. This callback must update the performance state of the genpd
  (in a platform dependent way).

The power domains can avoid supplying above callback, if they don't
support setting performance-states.

Currently we aren't propagating performance state changes of a subdomain
to its masters as we don't have hardware that needs it right now. Over
that, the performance states of subdomain and its masters may not have
one-to-one mapping and would require additional information. We can get
back to this once we have hardware that needs it.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch adds support to calculate the time spent by the generic
power domains in on and various idle states.
Signed-off-by: NThara Gopinath <thara.gopinath@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Allow generic power domain providers to override the ->xlate() callback
in case the default genpd_xlate_onecell() translation callback is not
good enough.

One potential use-case for this is to allow generic power domains to be
specified by an ID rather than an index.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>

Add a void *data pointer to struct generic_pm_domain_data. Because this
exists for each device associated with a genpd it will allow us to
assign per-device data if needed on a platform for control of that
specific device.
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NDave Gerlach <d-gerlach@ti.com>
Signed-off-by: NSantosh Shilimkar <ssantosh@kernel.org>

The current way to implement an always on PM domain consists of returning
-EBUSY from the ->power_off() callback. This is a bit different compared to
using the always on genpd governor, which prevents the PM domain from being
powered off via runtime suspend, but not via system suspend.

The approach to return -EBUSY from the ->power_off() callback to support
always on PM domains in genpd is suboptimal. That is because it requires
genpd to follow the regular execution path of the power off sequence, which
ends by invoking the ->power_off() callback.

To enable genpd to early abort the power off sequence for always on PM
domains, it needs static information about these configurations. Therefore
let's add a new genpd configuration flag, GENPD_FLAG_ALWAYS_ON.

Users of the new GENPD_FLAG_ALWAYS_ON flag, are by genpd required to make
sure the PM domain is powered on before calling pm_genpd_init(). Moreover,
users don't need to implement the ->power_off() callback, as genpd doesn't
ever invoke it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This allows to compile-test drivers that refer to governors (always by
reference) when CONFIG_PM_GENERIC_DOMAINS=n.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Generic Power Domains currently support turning on/off only in process
context. This prevents the usage of PM domains for domains that could be
powered on/off in a context where IRQs are disabled. Many such domains
exist today and do not get powered off, when the IRQ safe devices in
that domain are powered off, because of this limitation.

However, not all domains can operate in IRQ safe contexts. Genpd
therefore, has to support both cases where the domain may or may not
operate in IRQ safe contexts. Configuring genpd to use an appropriate
lock for that domain, would allow domains that have IRQ safe devices to
runtime suspend and resume, in atomic context.

To achieve domain specific locking, set the domain's ->flag to
GENPD_FLAG_IRQ_SAFE while defining the domain. This indicates that genpd
should use a spinlock instead of a mutex for locking the domain. Locking
is abstracted through genpd_lock() and genpd_unlock() functions that use
the flag to determine the appropriate lock to be used for that domain.

Domains that have lower latency to suspend and resume and can operate
with IRQs disabled may now be able to save power, when the component
devices and sub-domains are idle at runtime.

The restriction this imposes on the domain hierarchy is that non-IRQ
safe domains may not have IRQ-safe subdomains, but IRQ safe domains may
have IRQ safe and non-IRQ safe subdomains and devices.
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Abstract genpd lock/unlock calls, in preparation for domain specific
locks added in the following patches.
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Save the fwnode for the genpd state in the state node. PM Domain clients
may use the fwnode to read in the platform specific domain state
properties and associate them with the state.
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch allows domains to define idle states in the DT. SoC's can
define domain idle states in DT using the "domain-idle-states" property
of the domain provider. Add API to read the idle states from DT that can
be set in the genpd object.

This patch is based on the original patch by Marc Titinger.
Signed-off-by: NMarc Titinger <mtitinger+renesas@baylibre.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Residency of a domain's idle state indicates that the minimum idle time
for the domain's idle state to be beneficial for power. Add the
parameter to the state node. Future patches, will use the residency
value in the genpd governor to determine if it is worth while to enter
an idle state.
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Allow PM Domain states to be defined dynamically by the drivers. This
removes the limitation on the maximum number of states possible for a
domain.
Suggested-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NLina Iyer <lina.iyer@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a device supports PM domains that are subdomains of another PM
domain, then the PM domains should be removed in reverse order to
ensure that the subdomains are removed first. Furthermore, if there is
more than one provider, then there needs to be a way to remove the
domains in reverse order for a specific provider.

Add the function of_genpd_remove_last() to remove the last PM domain
added by a given PM domain provider and return the generic_pm_domain
structure for the PM domain that was removed.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The genpd framework allows users to add PM domains via the pm_genpd_init()
function, however, there is no corresponding function to remove a PM
domain. For most devices this may be fine as the PM domains are never
removed, however, for devices that wish to populate the PM domains from
within a driver, having the ability to remove a PM domain if the probing
of the device fails or the driver is unloaded is necessary.

Add the function pm_genpd_remove() to remove a PM domain by referencing
it's generic_pm_domain structure. Note that the bulk of the code that
removes the PM domain is placed in a separate local function
genpd_remove() (which is called by pm_genpd_remove()). The code is
structured in this way to prepare for adding another function to remove
a PM domain by provider that will also call genpd_remove(). Note that
users of genpd_remove() must call this function with the mutex,
gpd_list_lock, held.

PM domains can only be removed if the associated provider has been
removed, they are not a parent domain to another PM domain and have no
devices associated with them.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is possible that a device has more than one provider of PM domains
and to support the removal of a PM domain by provider, it is necessary
to store a reference to the provider in the PM domain structure.
Therefore, store a reference to the firmware node handle in the PM
domain structure and populate it when providers (only device-tree based
providers are currently supported by PM domains) are registered.

Please note that when removing PM domains, it is necessary to verify
that the PM domain provider has been removed from the list of providers
before the PM domain can be removed. To do this add another member to
the PM domain structure that indicates if the provider is present and
set this member accordingly when providers are added and removed.

Initialise the 'provider' and 'has_provider' members of the
generic_pm_domain structure when a PM domains is added by calling
pm_genpd_init().
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Functions __of_genpd_xlate_simple(), __of_genpd_xlate_onecell() and
__of_genpd_add_provider() are not used outside of the core generic PM
domain code. Therefore, reduce the number of APIs exposed by making
these static. At the same time don't expose the typedef for
genpd_xlate_t either and make this a local definition as well.

The functions are renamed to follow the naming conventions for static
functions in the generic PM domain core.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There should be no need to expose the generic_pm_domain structure to
clients and this eliminates the need to implement reference counting for
any external reference to a PM domain. Therefore, make the functions
pm_genpd_lookup_dev() and of_genpd_get_from_provider() private to the
PM domain core. The functions are renamed in accordance with the naming
conventions for genpd static functions.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Ideally, if we are returning a reference to a PM domain via a call to
of_genpd_get_from_provider(), then we should keep track of such
references via a reference count. The reference count could then be used
to determine if a PM domain can be safely removed. Alternatively, it is
possible to avoid such external references by providing APIs to access
the PM domain and hence, eliminate any calls to
of_genpd_get_from_provider().

Add new helper functions for adding a device and a subdomain to a PM
domain when using device-tree, so that external calls to
of_genpd_get_from_provider() can be removed.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The are already cases when pm_genpd_init() can fail. Currently we hide the
failures instead of propagating an error code, which is a better method.

Moreover, to prepare for future changes like moving away from using a
fixed array-size of the struct genpd_power_state, to instead dynamically
allocate data for it, the pm_genpd_init() API needs to be able to return
an error code, as allocation can fail.

Current users of the pm_genpd_init() is thus requested to start dealing
with error codes. In the transition phase, users will have to live with
only error messages being printed to log.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a PM domain is powered off when the first device starts its system PM
prepare phase, genpd prevents any further attempts to power on the PM
domain during the following system PM phases. Not until the system PM
complete phase is finalized for all devices in the PM domain, genpd again
allows it to be powered on.

This behaviour needs to be changed, as a subsystem/driver for a device in
the same PM domain may still need to be able to serve requests in some of
the system PM phases. Accordingly, it may need to runtime resume its
device and thus also request the corresponding PM domain to be powered on.

To deal with these scenarios, let's make the device operational in the
system PM prepare phase by runtime resuming it, no matter if the PM domain
is powered on or off. Changing this also enables us to remove genpd's
suspend_power_off flag, as it's being used to track this condition.
Additionally, we must allow the PM domain to be powered on via runtime PM
during the system PM phases.

This change also requires a fix in the AMD ACP (Audio CoProcessor) drm
driver. It registers a genpd to model the ACP as a PM domain, but
unfortunately it's also abuses genpd's "internal" suspend_power_off flag
to deal with a corner case at system PM resume.

More precisely, the so called SMU block powers on the ACP at system PM
resume, unconditionally if it's being used or not. This may lead to that
genpd's internal status of the power state, may not correctly reflect the
power state of the HW after a system PM resume.

Because of changing the behaviour of genpd, by runtime resuming devices in
the prepare phase, the AMD ACP drm driver no longer have to deal with this
corner case. So let's just drop the related code in this driver.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Acked-by: NMaruthi Bayyavarapu <maruthi.bayyavarapu@amd.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As a part of the ongoing consolidation of genpd, it's become questionable
whether clients actually needs to be able to assign their own set of
->save|restore_state() callbacks. Currently all users copes fine with the
default callbacks, so let's remove the configuration option and stick to
the default ones.

This enables further clarifications of the related code and let's also
rename pm_genpd_default_save|restore_state() into
__genpd_runtime_suspend|resume() to apply the rule of static functionnames
in genpd.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>