Commit 46420dd7 authored by Ulf Hansson's avatar Ulf Hansson Committed by Rafael J. Wysocki
Browse files

PM / Domains: Add APIs to attach/detach a PM domain for a device 



To maintain scalability let's add common methods to attach and detach
a PM domain for a device, dev_pm_domain_attach|detach().

Typically dev_pm_domain_attach() shall be invoked from subsystem level
code at the probe phase to try to attach a device to its PM domain.
The reversed actions may be done a the remove phase and then by
invoking dev_pm_domain_detach().

When attachment succeeds, the attach function should assign its
corresponding detach function to a new ->detach() callback added in the
struct dev_pm_domain.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Reviewed-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent aa42240a

drivers/base/power/common.c

+52 −0
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#include <linux/export.h>

#include <linux/slab.h>

#include <linux/pm_clock.h>

#include <linux/acpi.h>

#include <linux/pm_domain.h>



/**

 * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
@@ -82,3 +84,53 @@ int dev_pm_put_subsys_data(struct device *dev) 
	return ret;

}

EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);



/**

 * dev_pm_domain_attach - Attach a device to its PM domain.

 * @dev: Device to attach.

 * @power_on: Used to indicate whether we should power on the device.

 *

 * The @dev may only be attached to a single PM domain. By iterating through

 * the available alternatives we try to find a valid PM domain for the device.

 * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain

 * should be assigned by the corresponding attach function.

 *

 * This function should typically be invoked from subsystem level code during

 * the probe phase. Especially for those that holds devices which requires

 * power management through PM domains.

 *

 * Callers must ensure proper synchronization of this function with power

 * management callbacks.

 *

 * Returns 0 on successfully attached PM domain or negative error code.

 */

int dev_pm_domain_attach(struct device *dev, bool power_on)

{

	int ret;



	ret = acpi_dev_pm_attach(dev, power_on);

	if (ret)

		ret = genpd_dev_pm_attach(dev);



	return ret;

}

EXPORT_SYMBOL_GPL(dev_pm_domain_attach);



/**

 * dev_pm_domain_detach - Detach a device from its PM domain.

 * @dev: Device to attach.

 * @power_off: Used to indicate whether we should power off the device.

 *

 * This functions will reverse the actions from dev_pm_domain_attach() and thus

 * try to detach the @dev from its PM domain. Typically it should be invoked

 * from subsystem level code during the remove phase.

 *

 * Callers must ensure proper synchronization of this function with power

 * management callbacks.

 */

void dev_pm_domain_detach(struct device *dev, bool power_off)

{

	if (dev->pm_domain && dev->pm_domain->detach)

		dev->pm_domain->detach(dev, power_off);

}

EXPORT_SYMBOL_GPL(dev_pm_domain_detach);

include/linux/pm.h

+11 −0
Original line number Diff line number Diff line
@@ -622,6 +622,17 @@ struct dev_pm_domain { 
	void (*detach)(struct device *dev, bool power_off);

};



#ifdef CONFIG_PM

extern int dev_pm_domain_attach(struct device *dev, bool power_on);

extern void dev_pm_domain_detach(struct device *dev, bool power_off);

#else

static inline int dev_pm_domain_attach(struct device *dev, bool power_on)

{

	return -ENODEV;

}

static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {}

#endif



/*

 * The PM_EVENT_ messages are also used by drivers implementing the legacy

 * suspend framework, based on the ->suspend() and ->resume() callbacks common

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