kernel/linux.git/drivers/base/power/common.c, branch v6.6.132

PM: domains: Extend dev_pm_domain_detach() doc

2022-04-13T15:07:58+00:00

Mention all domain attach menthods which dev_pm_domain_detach() reverses. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Rafael J. Wysocki

PM / Domains: Introduce dev_pm_domain_start()

2019-11-13T10:41:50+00:00

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 Signed-off-by: Rafael J. Wysocki

drivers: base: power: add proper SPDX identifiers on files that did not have them.

2019-04-04T18:03:40+00:00

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" Signed-off-by: Greg Kroah-Hartman

PM / Domains: Mark "name" const in dev_pm_domain_attach_by_name()

2019-02-15T10:36:38+00:00

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 Reviewed-by: Stephen Boyd Acked-by: Viresh Kumar Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Introduce dev_pm_domain_attach_by_name()

2018-07-09T10:11:02+00:00

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 Tested-by: Rajendra Nayak Reviewed-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

PM / Domains: Add dev_pm_domain_attach_by_id() to manage multi PM domains

2018-06-06T07:09:22+00:00

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: Ulf Hansson Acked-by: Jon Hunter Tested-by: Jon Hunter Reviewed-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

PM / domains: Improve wording of dev_pm_domain_attach() comment

2018-05-17T10:41:49+00:00

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

PM / Domains: Don't return -EEXIST at attach when PM domain exists

2018-05-15T08:02:51+00:00

As dev_pm_domain_attach() isn't the only way to assign PM domain pointers to devices, clearly we must allow a device to have the pointer already being assigned. For this reason, return 0 instead of -EEXIST. Reported-by: Krzysztof Kozlowski Signed-off-by: Ulf Hansson Tested-by: Tested-by: Krzysztof Kozlowski Tested-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki

PM / Domains: Allow a better error handling of dev_pm_domain_attach()

2018-05-14T20:58:44+00:00

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: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Check for existing PM domain in dev_pm_domain_attach()

2018-05-14T20:58:44+00:00

Instead of checking if an existing PM domain pointer has been assigned in genpd_dev_pm_attach() and acpi_dev_pm_attach(), move the check to the common path in dev_pm_domain_attach(), thus potentially avoid one unnecessary check. Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki