mirror of
https://github.com/torvalds/linux.git
synced 2024-11-19 02:21:47 +00:00
1e95e3b2da
Clients using the dev_pm_put_subsys_data() API isn't interested of a return value. They care only of decreasing a reference to the device's pm_subsys_data. So, let's convert the API to a void function, which anyway seems like reasonable thing to do. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
131 lines
3.5 KiB
C
131 lines
3.5 KiB
C
/*
|
|
* drivers/base/power/common.c - Common device power management code.
|
|
*
|
|
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
|
|
*
|
|
* This file is released under the GPLv2.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/device.h>
|
|
#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.
|
|
* @dev: Device to handle.
|
|
*
|
|
* If power.subsys_data is NULL, point it to a new object, otherwise increment
|
|
* its reference counter. Return 0 if new object has been created or refcount
|
|
* increased, otherwise negative error code.
|
|
*/
|
|
int dev_pm_get_subsys_data(struct device *dev)
|
|
{
|
|
struct pm_subsys_data *psd;
|
|
|
|
psd = kzalloc(sizeof(*psd), GFP_KERNEL);
|
|
if (!psd)
|
|
return -ENOMEM;
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (dev->power.subsys_data) {
|
|
dev->power.subsys_data->refcount++;
|
|
} else {
|
|
spin_lock_init(&psd->lock);
|
|
psd->refcount = 1;
|
|
dev->power.subsys_data = psd;
|
|
pm_clk_init(dev);
|
|
psd = NULL;
|
|
}
|
|
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
/* kfree() verifies that its argument is nonzero. */
|
|
kfree(psd);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
|
|
|
|
/**
|
|
* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
|
|
* @dev: Device to handle.
|
|
*
|
|
* If the reference counter of power.subsys_data is zero after dropping the
|
|
* reference, power.subsys_data is removed.
|
|
*/
|
|
void dev_pm_put_subsys_data(struct device *dev)
|
|
{
|
|
struct pm_subsys_data *psd;
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
psd = dev_to_psd(dev);
|
|
if (!psd)
|
|
goto out;
|
|
|
|
if (--psd->refcount == 0)
|
|
dev->power.subsys_data = NULL;
|
|
else
|
|
psd = NULL;
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
kfree(psd);
|
|
}
|
|
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);
|