linux-toradex.git/include/linux/pm_domain.h, branch v3.2-rc5

PM / Domains: Split device PM domain data into base and need_restore

2011-09-26T18:22:02+00:00

The struct pm_domain_data data type is defined in such a way that
adding new fields specific to the generic PM domains code will
require include/linux/pm.h to be modified.  As a result, data types
used only by the generic PM domains code will be defined in two
headers, although they all should be defined in pm_domain.h and
pm.h will need to include more headers, which won't be very nice.

For this reason change the definition of struct pm_subsys_data
so that its domain_data member is a pointer, which will allow
struct pm_domain_data to be subclassed by various PM domains
implementations.  Remove the need_restore member from
struct pm_domain_data and make the generic PM domains code
subclass it by adding the need_restore member to the new data type.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Preliminary support for devices with power.irq_safe set

2011-08-25T13:37:04+00:00

The generic PM domains framework currently doesn't work with devices
whose power.irq_safe flag is set, because runtime PM callbacks for
such devices are run with interrupts disabled and the callbacks
provided by the generic PM domains framework use domain mutexes
and may sleep.  However, such devices very well may belong to
power domains on some systems, so the generic PM domains framework
should take them into account.

For this reason, modify the generic PM domains framework so that the
domain .power_off() and .power_on() callbacks are never executed for
a domain containing devices with power.irq_safe set, although the
.stop_device() and .start_device() callbacks are still run for them.

Additionally, introduce a flag allowing the creator of a
struct generic_pm_domain object to indicate that its .stop_device()
and .start_device() callbacks may be run in interrupt context
(might_sleep_if() triggers if that flag is not set and one of those
callbacks is run in interrupt context).

Signed-off-by: Rafael J. Wysocki

PM / Domains: Use power.sybsys_data to reduce overhead

2011-08-25T13:34:12+00:00

Currently pm_genpd_runtime_resume() has to walk the list of devices
from the device's PM domain to find the corresponding device list
object containing the need_restore field to check if the driver's
.runtime_resume() callback should be executed for the device.
This is suboptimal and can be simplified by using power.sybsys_data
to store device information used by the generic PM domains code.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Rename GPD_STATE_WAIT_PARENT to GPD_STATE_WAIT_MASTER

2011-08-25T13:33:45+00:00

Since it is now possible for a PM domain to have multiple masters
instead of one parent, rename the "wait for parent" status to reflect
the new situation.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Allow generic PM domains to have multiple masters

2011-08-25T13:33:44+00:00

Currently, for a given generic PM domain there may be only one parent
domain (i.e. a PM domain it depends on).  However, there is at least
one real-life case in which there should be two parents (masters) for
one PM domain (the A3RV domain on SH7372 turns out to depend on the
A4LC domain and it depends on the A4R domain and the same time). For
this reason, allow a PM domain to have multiple parents (masters) by
introducing objects representing links between PM domains.

The (logical) links between PM domains represent relationships in
which one domain is a master (i.e. it is depended on) and another
domain is a slave (i.e. it depends on the master) with the rule that
the slave cannot be powered on if the master is not powered on and
the master cannot be powered off if the slave is not powered off.
Each struct generic_pm_domain object representing a PM domain has
two lists of links, a list of links in which it is a master and
a list of links in which it is a slave.  The first of these lists
replaces the list of subdomains and the second one is used in place
of the parent pointer.

Each link is represented by struct gpd_link object containing
pointers to the master and the slave and two struct list_head
members allowing it to hook into two lists (the master's list
of "master" links and the slave's list of "slave" links).  This
allows the code to get to the link from each side (either from
the master or from the slave) and follow it in each direction.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Add "wait for parent" status for generic PM domains

2011-08-25T13:33:44+00:00

The next patch will make it possible for a generic PM domain to have
multiple parents (i.e. multiple PM domains it depends on).  To
prepare for that change it is necessary to change pm_genpd_poweron()
so that it doesn't jump to the start label after running itself
recursively for the parent domain.  For this purpose, introduce a new
PM domain status value GPD_STATE_WAIT_PARENT that will be set by
pm_genpd_poweron() before calling itself recursively for the parent
domain and modify the code in drivers/base/power/domain.c so that
the GPD_STATE_WAIT_PARENT status is guaranteed to be preserved during
the execution of pm_genpd_poweron() for the parent.

This change also causes pm_genpd_add_subdomain() and
pm_genpd_remove_subdomain() to wait for started pm_genpd_poweron() to
complete and allows pm_genpd_runtime_resume() to avoid dropping the
lock after powering on the PM domain.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Implement subdomain counters as atomic fields

2011-08-25T13:33:43+00:00

Currently, pm_genpd_poweron() and pm_genpd_poweroff() need to take
the parent PM domain's lock in order to modify the parent's counter
of active subdomains in a nonracy way.  This causes the locking to be
considerably complex and in fact is not necessary, because the
subdomain counters may be implemented as atomic fields and they
won't have to be modified under a lock.

Replace the unsigned in sd_count field in struct generic_pm_domain
by an atomic_t one and modify the code in drivers/base/power/domain.c
to take this change into account.

This patch doesn't change the locking yet, that is going to be done
in a separate subsequent patch.

Signed-off-by: Rafael J. Wysocki

PM / Domains: Fix build for CONFIG_PM_RUNTIME unset

2011-08-14T11:34:31+00:00

Function genpd_queue_power_off_work() is not defined for
CONFIG_PM_RUNTIME, so pm_genpd_poweroff_unused() causes a build
error to happen in that case.  Fix the problem by making
pm_genpd_poweroff_unused() depend on CONFIG_PM_RUNTIME too.

Signed-off-by: Rafael J. Wysocki

ARM / shmobile: Use genpd_queue_power_off_work()

2011-07-14T18:59:07+00:00

Make pd_power_down_a3rv() use genpd_queue_power_off_work() to queue
up the powering off of the A4LC domain to avoid queuing it up when
it is pending.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Magnus Damm

PM / Domains: Introduce function to power off all unused PM domains

2011-07-13T10:31:52+00:00

Add a new function pm_genpd_poweroff_unused() queuing up the
execution of pm_genpd_poweroff() for every initialized generic PM
domain.  Calling it will cause every generic PM domain without
devices in use to be powered off.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Magnus Damm