linux-stable.git/include/linux/pm_domain.h, branch v4.11.2

PM / Domains: Provide dummy governors if CONFIG_PM_GENERIC_DOMAINS=n

2017-02-09T13:29:27+00:00

This allows to compile-test drivers that refer to governors (always by
reference) when CONFIG_PM_GENERIC_DOMAINS=n.

Signed-off-by: Geert Uytterhoeven 
Acked-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Support IRQ safe PM domains

2016-10-21T20:20:56+00:00

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: Lina Iyer 
Acked-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Abstract genpd locking

2016-10-21T20:20:47+00:00

Abstract genpd lock/unlock calls, in preparation for domain specific
locks added in the following patches.

Signed-off-by: Lina Iyer 
Signed-off-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Save the fwnode in genpd_power_state

2016-10-21T20:20:27+00:00

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: Lina Iyer 
Acked-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Allow domain power states to be read from DT

2016-10-21T20:20:15+00:00

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: Marc Titinger 
Signed-off-by: Ulf Hansson 
Signed-off-by: Lina Iyer 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Add residency property to genpd states

2016-10-21T20:20:07+00:00

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: Lina Iyer 
Acked-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Make genpd state allocation dynamic

2016-10-21T20:19:36+00:00

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: Ulf Hansson 
Signed-off-by: Lina Iyer 
Acked-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Add support for removing nested PM domains by provider

2016-09-13T00:49:34+00:00

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: Jon Hunter 
Acked-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Add support for removing PM domains

2016-09-13T00:49:34+00:00

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: Jon Hunter 
Acked-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Store the provider in the PM domain structure

2016-09-13T00:49:34+00:00

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: Jon Hunter 
Acked-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki