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path: root/drivers/base/power/domain.c
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2012-09-06PM / Domains: Fix compilation warning related to genpd_start_dev_no_timing()Sachin Kamat1-6/+6
Function genpd_start_dev_no_timing was accessed inside CONFIG_PM_RUNTIME macro but defined outside it. When the above macro was not defined the compiler gave the following warning: drivers/base/power/domain.c:96:12: warning: ‘genpd_start_dev_no_timing’ defined but not used [-Wunused-function] Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Operations related to cpuidle using domain namesRafael J. Wysocki1-0/+19
Make it possible to use domain names in operations connecting cpuidle to and disconnecting it from a PM domain. This is useful on platforms where PM domain objects are organized in such a way that the names of the domains are easier to use than the addresses of those objects. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Document cpuidle-related functions and change their namesRafael J. Wysocki1-2/+18
The names of the cpuidle-related functions in drivers/base/power/domain.c are inconsistent with the names of the other exported functions in that file (the "pm_" prefix is missing from them) and they are missing kerneldoc comments. Fix that by adding the missing "pm_" prefix to the names of those functions and add kerneldoc comments documenting them. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Add power-on function using names to identify domainsRafael J. Wysocki1-15/+31
It sometimes is necessary to turn on a given PM domain when only the name of it is known and the domain pointer is not readily available. For this reason, add a new helper function, pm_genpd_name_poweron(), allowing the caller to turn on a PM domain using its name for identification. To avoid code duplication, move the domain lookup code to a separate function. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Make it possible to use names when adding subdomainsRafael J. Wysocki1-1/+31
Add a new helper function, pm_genpd_add_subdomain_names(), allowing the caller to add a subdomain to a generic PM domain using names for domain identification (both domains have to be initialized before). This function is useful for adding subdomains to PM domains whose representations are stored in tables, when the caller doesn't know the indices of the domain to add the subdomain to and of the subdomain itself, but it knows the domains' names. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Make it possible to use domain names when adding devicesRafael J. Wysocki1-0/+27
Add a new helper function __pm_genpd_name_add_device() allowing a device to be added to a (registered) generic PM domain identified by name. Add a wrapper around it, pm_genpd_name_add_device(), passing NULL as the last argument and reorganize pm_domains.h for the new functions to be defined consistently with the existing ones. These functions are useful for adding devices to PM domains whose representations are stored in tables, when the caller doesn't know the index of the domain to add the device to, but it knows the domain's name. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM: Do not use the syscore flag for runtime PMRafael J. Wysocki1-1/+1
The syscore device PM flag used to mark the devices (belonging to PM domains) that should never be turned off, except for the system core (syscore) suspend/hibernation and resume stages, need not be accessed by the runtime PM core functions, because all of the devices it is set for need to be marked as "irq safe" anyway and are protected from being turned off by runtime PM by ensuring that their usage counters are always set. For this reason, make the syscore flag system-wide PM-specific and simplify the code used for manipulating it, because it need not acquire the device's power.lock any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Do not measure start time for "irq safe" devicesRafael J. Wysocki1-1/+7
The genpd_start_dev() routine used by pm_genpd_runtime_resume() to put "irq safe" devices into the full power state measures the time necessary to "start" the device and updates its PM QoS timing data if necessary. This may lead to a deadlock if the given device is a clock source and genpd_start_dev() is invoked from within the clock source's .enable() routine, which will happen if that routine uses pm_runtime_get_sync(), for example, to ensure that the device is operational. For this reason, introduce a special routine analogous to genpd_start_dev(), called genpd_start_dev_no_timing(), that doesn't carry out the time measurement, and make pm_genpd_runtime_resume() use it instead of genpd_start_dev() to power up "irq safe" devices. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Move syscore flag from subsys data to struct deviceRafael J. Wysocki1-31/+6
The syscore device PM flag is used to mark the devices (belonging to a PM domain) that should never be turned off, except for the system core (syscore) suspend/hibernation and resume stages. That flag is stored in the device's struct pm_subsys_data object whose address is available from struct device. However, in some situations it may be convenient to set that flag before the device is added to a PM domain, so it is better to move it directly to the "power" member of struct device. Then, it can be checked by the routines in drivers/base/power/runtime.c and drivers/base/power/main.c, which is more straightforward. This also reduces the number of dev_gpd_data() invocations in the generic PM domains framework, so the overhead related to the syscore flag is slightly smaller. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
2012-09-04PM / Domains: Rename the always_on device flag to syscoreRafael J. Wysocki1-12/+12
The always_on device flag is used to mark the devices (belonging to a PM domain) that should never be turned off, except for the system core (syscore) suspend/hibernation and resume stages. Change name of that flag to "syscore" to better reflect its purpose. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
2012-09-04PM / Domains: Add power off/on function for system core suspend stageRafael J. Wysocki1-6/+51
Introduce function pm_genpd_syscore_switch() and two wrappers around it, pm_genpd_syscore_poweroff() and pm_genpd_syscore_poweron(), allowing the callers to let the generic PM domains framework know that the given device is not necessary any more and its PM domain can be turned off (the former) or that the given device will be required immediately, so its PM domain has to be turned on (the latter) during the system core (syscore) stage of system suspend (or hibernation) and resume. These functions will be used for handling devices registered as clock sources and clock event devices that belong to PM domains. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04PM / Domains: Introduce simplified power on routine for system resumeRafael J. Wysocki1-4/+30
Introduce function pm_genpd_sync_poweron() for restoring domain power during resume from system suspend and hibernation. It can be much simpler than pm_genpd_poweron(), because it doesn't have to care about locking and it can skip many checks done by the latter. Modify pm_genpd_resume_noirq() and pm_genpd_restore_noirq() to use the new function. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-12PM / Domains: Fix build warning for CONFIG_PM_RUNTIME unsetRafael J. Wysocki1-13/+13
The functions genpd_save_dev() and genpd_restore_dev() are not used for CONFIG_PM_RUNTIME unset, so move them under an appropriate #ifdef. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-11PM / Domains: Replace plain integer with NULL pointer in domain.c fileSachin Kamat1-1/+1
Fixes the following sparse warning: drivers/base/power/domain.c:1679:55: warning: Using plain integer as NULL pointer Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-10PM / Domains: Add missing static storage class specifier in domain.c fileSachin Kamat1-1/+1
Fixes the folloiwng sparse warning: drivers/base/power/domain.c:149:5: warning: symbol '__pm_genpd_poweron' was not declared. Should it be static? Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-05PM / Domains: Allow device callbacks to be added at any timeRafael J. Wysocki1-14/+50
Make it possible to modify device callbacks used by the generic PM domains core code at any time, not only after the device has been added to a domain. This will allow device drivers to provide their own device PM domain callbacks even if they are registered before adding the devices to PM domains. For this purpose, use the observation that the struct generic_pm_domain_data object containing the relevant callback pointers may be allocated by pm_genpd_add_callbacks() and the callbacks may be set before __pm_genpd_add_device() is run for the given device. This object will then be used by __pm_genpd_add_device(), but it has to be protected from premature removal by reference counting. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-05PM / Domains: Add device domain data reference counterRafael J. Wysocki1-26/+57
Add a mechanism for counting references to the struct generic_pm_domain_data object pointed to by dev->power.subsys_data->domain_data if the device in question belongs to a generic PM domain. This change is necessary for a subsequent patch making it possible to allocate that object from within pm_genpd_add_callbacks(), so that drivers can attach their PM domain device callbacks to devices before those devices are added to PM domains. This patch has been tested on the SH7372 Mackerel board. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-03PM / Domains: Add preliminary support for cpuidle, v2Rafael J. Wysocki1-0/+117
On some systems there are CPU cores located in the same power domains as I/O devices. Then, power can only be removed from the domain if all I/O devices in it are not in use and the CPU core is idle. Add preliminary support for that to the generic PM domains framework. First, the platform is expected to provide a cpuidle driver with one extra state designated for use with the generic PM domains code. This state should be initially disabled and its exit_latency value should be set to whatever time is needed to bring up the CPU core itself after restoring power to it, not including the domain's power on latency. Its .enter() callback should point to a procedure that will remove power from the domain containing the CPU core at the end of the CPU power transition. The remaining characteristics of the extra cpuidle state, referred to as the "domain" cpuidle state below, (e.g. power usage, target residency) should be populated in accordance with the properties of the hardware. Next, the platform should execute genpd_attach_cpuidle() on the PM domain containing the CPU core. That will cause the generic PM domains framework to treat that domain in a special way such that: * When all devices in the domain have been suspended and it is about to be turned off, the states of the devices will be saved, but power will not be removed from the domain. Instead, the "domain" cpuidle state will be enabled so that power can be removed from the domain when the CPU core is idle and the state has been chosen as the target by the cpuidle governor. * When the first I/O device in the domain is resumed and __pm_genpd_poweron(() is called for the first time after power has been removed from the domain, the "domain" cpuidle state will be disabled to avoid subsequent surprise power removals via cpuidle. The effective exit_latency value of the "domain" cpuidle state depends on the time needed to bring up the CPU core itself after restoring power to it as well as on the power on latency of the domain containing the CPU core. Thus the "domain" cpuidle state's exit_latency has to be recomputed every time the domain's power on latency is updated, which may happen every time power is restored to the domain, if the measured power on latency is greater than the latency stored in the corresponding generic_pm_domain structure. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
2012-07-01PM / Domains: Do not stop devices after restoring their statesRafael J. Wysocki1-11/+5
While resuming a device belonging to a PM domain, pm_genpd_runtime_resume() calls __pm_genpd_restore_device() to restore its state, if necessary. The latter starts the device, using genpd_start_dev(), restores its state, using genpd_restore_dev(), and then stops it, using genpd_stop_dev(). However, this last operation is not necessary, because the device is supposed to be operational after pm_genpd_runtime_resume() has returned and because of it pm_genpd_runtime_resume() has to call genpd_start_dev() once again for the "restored" device, which is inefficient. To make things more efficient, remove the call to genpd_stop_dev() from __pm_genpd_restore_device() and the direct call to genpd_start_dev() from pm_genpd_runtime_resume(). [Of course, genpd_start_dev() still has to be called by it for devices with the power.irq_safe flag set, because __pm_genpd_restore_device() is not executed for them.] This change has been tested on the SH7372 Mackerel board. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-01PM / Domains: Use subsystem runtime suspend/resume callbacks by defaultRafael J. Wysocki1-8/+24
Currently, the default "save state" and "restore state" routines for generic PM domains, pm_genpd_default_save_state() and pm_genpd_default_restore_state(), respectively, only use runtime PM callbacks provided by device drivers, but in general those callbacks need not provide the entire necessary functionality. Namely, in general it may be necessary to execute subsystem (i.e. device type, device class or bus type) callbacks that will carry out all of the necessary operations. For this reason, modify pm_genpd_default_save_state() and pm_genpd_default_restore_state() to execute subsystem callbacks, if they are provided, and fall back to driver callbacks otherwise. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-18PM / Domains: Make it possible to add devices to inactive domainsRafael J. Wysocki1-6/+21
The generic PM domains core code currently requires domains to be in the "power on" state for adding devices to them, but this limitation turns out to be inconvenient in some situations, so remove it. For this purpose, make __pm_genpd_add_device() set the device's need_restore flag if the domain is in the "power off" state, so that the device's "restore state" (usually .runtime_resume()) callback is executed when it is resumed after the domain has been turned on. If the domain is in the "power on" state, the device's need_restore flag will be cleared by __pm_genpd_add_device(), so that its "save state" (usually .runtime_suspend()) callback is executed when the domain is about to be turned off. However, since that default behavior need not be always desirable, add a helper function pm_genpd_dev_need_restore() allowing a device's need_restore flag to be set/unset at any time. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-11PM / Domains: Fix link checking when add subdomainHuang Ying1-1/+1
Current pm_genpd_add_subdomain() will allow duplicated link between master and slave domain. This patch fixed it. Because when current pm_genpd_add_subdomain() checks whether the link between the master and slave generic PM domain already exists, slave_links instead of master_links of master domain is used. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-05PM / Domains: Cache device stop and domain power off governor results, v3Rafael J. Wysocki1-16/+104
The results of the default device stop and domain power off governor functions for generic PM domains, default_stop_ok() and default_power_down_ok(), depend only on the timing data of devices, which are static, and on their PM QoS constraints. Thus, in theory, these functions only need to carry out their computations, which may be time consuming in general, when it is known that the PM QoS constraint of at least one of the devices in question has changed. Use the PM QoS notifiers of devices to implement that. First, introduce new fields, constraint_changed and max_off_time_changed, into struct gpd_timing_data and struct generic_pm_domain, respectively, and register a PM QoS notifier function when adding a device into a domain that will set those fields to 'true' whenever the device's PM QoS constraint is modified. Second, make default_stop_ok() and default_power_down_ok() use those fields to decide whether or not to carry out their computations from scratch. The device and PM domain hierarchies are taken into account in that and the expense is that the changes of PM QoS constraints of suspended devices will not be taken into account immediately, which isn't guaranteed anyway in general. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-05PM / Domains: Make device removal more straightforwardRafael J. Wysocki1-16/+11
The removal of a device from a PM domain doesn't have to browse the domain's device list, because it can check directly if the device belongs to the given domain. Moreover, it should clear the domain_data pointer in dev->power.subsys_data, because dev_pm_put_subsys_data(dev) may not remove dev->power.subsys_data and the stale domain data pointer may cause problems to happen. Rework pm_genpd_remove_device() taking the above observations into account. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-01PM / Runtime: Remove device fields related to suspend time, v2Rafael J. Wysocki1-13/+0
After the previous changes in default_stop_ok() and default_power_down_ok() for PM domains, there are two fields in struct dev_pm_info that aren't necessary any more, suspend_time and max_time_suspended_ns. Remove those fields along with all of the code that accesses them, which simplifies the runtime PM framework quite a bit. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-01PM / Domains: Rework default domain power off governor function, v2Rafael J. Wysocki1-1/+1
The existing default domain power down governor function for PM domains, default_power_down_ok(), is supposed to check whether or not the PM QoS latency constraints of the devices in the domain will be violated if the domain is turned off by pm_genpd_poweroff(). However, the computations carried out by it don't reflect the definition of the PM QoS latency constrait in Documentation/ABI/testing/sysfs-devices-power. Make default_power_down_ok() follow the definition of the PM QoS latency constrait. In particular, make it only take latencies into account, because it doesn't matter how much time has elapsed since the domain's devices were suspended for the computation. Remove the break_even_ns and power_off_time fields from struct generic_pm_domain, because they are not necessary any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-01PM / Domains: Rework default device stop governor function, v2Rafael J. Wysocki1-0/+1
The existing default device stop governor function for PM domains, default_stop_ok(), is supposed to check whether or not the device's PM QoS latency constraint will be violated if the device is stopped by pm_genpd_runtime_suspend(). However, the computations carried out by it don't reflect the definition of the PM QoS latency constrait in Documentation/ABI/testing/sysfs-devices-power. Make default_stop_ok() follow the definition of the PM QoS latency constrait. In particular, make it take the device's start and stop latencies correctly. Add a new field, effective_constraint_ns, to struct gpd_timing_data and use it to store the difference between the device's PM QoS constraint and its resume latency for use by the device's parent (the effective_constraint_ns values for the children are used for computing the parent's one along with its PM QoS constraint). Remove the break_even_ns field from struct gpd_timing_data, because it's not used any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-19PM / Domains: Check domain status during hibernation restore of devicesRafael J. Wysocki1-0/+3
Power domains that were off before hibernation shouldn't be turned on during device restore, so prevent that from happening. This change fixes up commit 65533bbf63b4f37723fdfedc73d0653958973323 PM / Domains: Fix hibernation restore of devices, v2 that didn't include it by mistake. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-16PM / Domains: Introduce "always on" device flagRafael J. Wysocki1-6/+31
The TMU device on the Mackerel board belongs to the A4R power domain and loses power when the domain is turned off. Unfortunately, the TMU driver is not prepared to cope with such situations and crashes the system when that happens. To work around this problem introduce a new helper function, pm_genpd_dev_always_on(), allowing a device driver to mark its device as "always on" in case it belongs to a PM domain, which will make the generic PM domains core code avoid powering off the domain containing the device, both at run time and during system suspend. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Simon Horman <horms@verge.net.au> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: stable@vger.kernel.org
2012-03-16PM / Domains: Fix hibernation restore of devices, v2Rafael J. Wysocki1-10/+21
During resume from hibernation pm_genpd_restore_noirq() should only power off domains whose suspend_power_off flags are set once and not every time it is called for a device in the given domain. Moreover, it shouldn't decrement genpd->suspended_count, because that field is not touched during device freezing and therefore it is always equal to 0 when pm_genpd_restore_noirq() runs for the first device in the given domain. This means pm_genpd_restore_noirq() may use genpd->suspended_count to determine whether or not it it has been called for the domain in question already in this cycle (it only needs to increment that field every time it runs for this purpose) and whether or not it should check if the domain needs to be powered off. For that to work, though, pm_genpd_prepare() has to clear genpd->suspended_count when it runs for the first device in the given domain (in which case that flag need not be cleared during domain initialization). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@vger.kernel.org
2012-03-16PM / Domains: Fix handling of wakeup devices during system resumeRafael J. Wysocki1-1/+2
During system suspend pm_genpd_suspend_noirq() checks if the given device is in a wakeup path (i.e. it appears to be needed for one or more wakeup devices to work or is a wakeup device itself) and if it needs to be "active" for wakeup to work. If that is the case, the function returns 0 without incrementing the device domain's counter of suspended devices and without executing genpd_stop_dev() for the device. In consequence, the device is not stopped (e.g. its clock isn't disabled) and power is always supplied to its domain in the resulting system sleep state. However, pm_genpd_resume_noirq() doesn't repeat that check and it runs genpd_start_dev() and decrements the domain's counter of suspended devices even for the wakeup device that weren't stopped by pm_genpd_suspend_noirq(). As a result, the start callback may be run unnecessarily for them and their domains' counters of suspended devices may become negative. Both outcomes aren't desirable, so fix pm_genpd_resume_noirq() to look for wakeup devices that might not be stopped by during system suspend. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Simon Horman <horms@verge.net.au> Cc: stable@vger.kernel.org
2012-02-01Merge branch 'v3.4-for-rafael' of ↵Rafael J. Wysocki1-0/+32
git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into pm-domains * 'v3.4-for-rafael' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung: ARM: EXYNOS: Hook up power domains to generic power domain infrastructure PM / Domains: Add OF support
2012-01-29PM / Domains: Run late/early device suspend callbacks at the right timeRafael J. Wysocki1-46/+111
After the introduction of the late/early phases of device suspend/resume during system-wide power transitions it is possible to make the generic PM domains code execute its default late/early device suspend/resume callbacks during those phases instead of the corresponding _noirq phases. The _noirq device suspend/resume phases were only used for executing those callbacks, because this was the only way it could be done, but now we can do better. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-01-27PM / Domains: Add OF supportThomas Abraham1-0/+32
A device node pointer is added to generic pm domain structure to associate the domain with a node in the device tree. The platform code parses the device tree to find available nodes representing the generic power domain, instantiates the available domains and initializes them by calling pm_genpd_init(). Nodes representing the devices include a phandle of the power domain to which it belongs. As these devices get instantiated, the driver code checkes for availability of a power domain phandle, converts the phandle to a device node and uses the new pm_genpd_of_add_device() api to associate the device with a power domain. pm_genpd_of_add_device() runs through its list of registered power domains and matches the OF node of the domain with the one specified as the parameter. If a match is found, the device is associated with the matched domain. Cc: Rob Herring <rob.herring@calxeda.com> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2012-01-14PM / Domains: Fix build for CONFIG_PM_SLEEP unsetRafael J. Wysocki1-0/+15
Some callback functions defined in drivers/base/power/domain.c are only necessary if CONFIG_PM_SLEEP is set and they call some other functions that are only available in that case. For this reason, they should not be compiled at all when CONFIG_PM_SLEEP is not set. Reported-by: Magnus Damm <damm@opensource.se> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-08PM / Domains: Fix default system suspend/resume operationsRafael J. Wysocki1-8/+8
Commit d23b9b00cdde5c93b914a172cecd57d5625fcd04 (PM / Domains: Rework system suspend callback routines (v2)) broke the system suspend and resume handling by devices belonging to generic PM domains, because it used freeze/thaw callbacks instead of suspend/resume ones and didn't initialize device callbacks for system suspend/resume properly at all. Fix those problems. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-06PM / Domains: Make it possible to assign names to generic PM domainsRafael J. Wysocki1-2/+12
Add a name member pointer to struct generic_pm_domain and use it in diagnostic messages regarding the domain power-off and power-on latencies. Update the ARM shmobile SH7372 code to assign names to the PM domains used by it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
2011-12-01PM / Domains: Automatically update overoptimistic latency informationRafael J. Wysocki1-4/+39
Measure the time of execution of the .stop(), .start(), .save_state() and .restore_state() PM domain device callbacks and if the result is greater than the corresponding latency value stored in the device's struct generic_pm_domain_data object, replace the inaccurate value with the measured time. Do analogously for the PM domains' .power_off() and .power_off() callbacks. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Domains: Add default power off governor function (v4)Rafael J. Wysocki1-0/+12
Add a function deciding whether or not a given PM domain should be powered off on the basis of the PM QoS constraints of devices belonging to it and their PM QoS timing data. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Domains: Add device stop governor function (v4)Rafael J. Wysocki1-7/+26
Add a function deciding whether or not devices should be stopped in pm_genpd_runtime_suspend() depending on their PM QoS constraints and stop/start timing values. Make it possible to add information used by this function to device objects. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
2011-12-01PM / Domains: Rework system suspend callback routines (v2)Rafael J. Wysocki1-99/+150
The current generic PM domains code attempts to use the generic system suspend operations along with the domains' device stop/start routines, which requires device drivers to assume that their system suspend/resume (and hibernation/restore) callbacks will always be used with generic PM domains. However, in theory, the same hardware may be used in devices that don't belong to any PM domain, in which case it would be necessary to add "fake" PM domains to satisfy the above assumption. Also, the domain the hardware belongs to may not be handled with the help of the generic code. To allow device drivers that may be used along with the generic PM domains code of more flexibility, add new device callbacks, .suspend(), .suspend_late(), .resume_early(), .resume(), .freeze(), .freeze_late(), .thaw_early(), and .thaw(), that can be supplied by the drivers in addition to their "standard" system suspend and hibernation callbacks. These new callbacks, if defined, will be used by the generic PM domains code for the handling of system suspend and hibernation instead of the "standard" ones. This will allow drivers to be designed to work with generic PM domains as well as without them. For backwards compatibility, introduce default implementations of the new callbacks for PM domains that will execute pm_generic_suspend(), pm_generic_suspend_noirq(), pm_generic_resume_noirq(), pm_generic_resume(), pm_generic_freeze(), pm_generic_freeze_noirq(), pm_generic_thaw_noirq(), and pm_generic_thaw(), respectively, for the given device if its driver doesn't define those callbacks. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Domains: Introduce "save/restore state" device callbacksRafael J. Wysocki1-12/+56
The current PM domains code uses device drivers' .runtime_suspend() and .runtime_resume() callbacks as the "save device state" and "restore device state" operations, which may not be appropriate in general, because it forces drivers to assume that they always will be used with generic PM domains. However, in theory, the same hardware may be used in devices that don't belong to any PM domain, in which case it would be necessary to add "fake" PM domains to satisfy the above assumption. It also may be located in a PM domain that's not handled with the help of the generic code. To allow device drivers that may be used along with the generic PM domains code of more flexibility, introduce new device callbacks, .save_state() and .restore_state(), that can be supplied by the drivers in addition to their "standard" runtime PM callbacks. This will allow the drivers to be designed to work with generic PM domains as well as without them. For backwards compatibility, introduce default .save_state() and .restore_state() callback routines for PM domains that will execute a device driver's .runtime_suspend() and .runtime_resume() callbacks, respectively, for the given device if the driver doesn't provide its own implementations of .save_state() and .restore_state(). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Domains: Make it possible to use per-device domain callbacksRafael J. Wysocki1-37/+115
The current generic PM domains code requires that the same .stop(), .start() and .active_wakeup() device callback routines be used for all devices in the given domain, which is inflexible and may not cover some specific use cases. For this reason, make it possible to use device specific .start()/.stop() and .active_wakeup() callback routines by adding corresponding callback pointers to struct generic_pm_domain_data. Add a new helper routine, pm_genpd_register_callbacks(), that can be used to populate the new per-device callback pointers. Modify the shmobile's power domains code to allow drivers to add their own code to be run during the device stop and start operations with the help of the new callback pointers. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
2011-10-22PM / Sleep: Mark devices involved in wakeup signaling during suspendRafael J. Wysocki1-2/+2
The generic PM domains code in drivers/base/power/domain.c has to avoid powering off domains that provide power to wakeup devices during system suspend. Currently, however, this only works for wakeup devices directly belonging to the given domain and not for their children (or the children of their children and so on). Thus, if there's a wakeup device whose parent belongs to a power domain handled by the generic PM domains code, the domain will be powered off during system suspend preventing the device from signaling wakeup. To address this problem introduce a device flag, power.wakeup_path, that will be set during system suspend for all wakeup devices, their parents, the parents of their parents and so on. This way, all wakeup paths in the device hierarchy will be marked and the generic PM domains code will only need to avoid powering off domains containing devices whose power.wakeup_path is set. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-09-26PM / Domains: Split device PM domain data into base and need_restoreRafael J. Wysocki1-9/+19
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 <rjw@sisk.pl>
2011-08-25PM / Domains: Preliminary support for devices with power.irq_safe setRafael J. Wysocki1-1/+18
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 <rjw@sisk.pl>
2011-08-25PM / Domains: Use power.sybsys_data to reduce overheadRafael J. Wysocki1-57/+30
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 <rjw@sisk.pl>
2011-08-25PM / Domains: Rename argument of pm_genpd_add_subdomain()Rafael J. Wysocki1-13/+13
Change the name of the second argument of pm_genpd_add_subdomain() so that it is (a) shorter and (b) in agreement with the name of the second argument of pm_genpd_add_subdomain(). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM / Domains: Rename GPD_STATE_WAIT_PARENT to GPD_STATE_WAIT_MASTERRafael J. Wysocki1-4/+4
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 <rjw@sisk.pl>
2011-08-25PM / Domains: Allow generic PM domains to have multiple mastersRafael J. Wysocki1-41/+58
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 <rjw@sisk.pl>