/*
* drivers/base/power/domain.c - Common code related to device power domains.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
*
* This file is released under the GPLv2.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/suspend.h>
static LIST_HEAD(gpd_list);
static DEFINE_MUTEX(gpd_list_lock);
#ifdef CONFIG_PM
static struct generic_pm_domain *dev_to_genpd(struct device *dev)
{
if (IS_ERR_OR_NULL(dev->pm_domain))
return ERR_PTR(-EINVAL);
return pd_to_genpd(dev->pm_domain);
}
static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
{
bool ret = false;
if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
ret = !!atomic_dec_and_test(&genpd->sd_count);
return ret;
}
static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
{
atomic_inc(&genpd->sd_count);
smp_mb__after_atomic_inc();
}
static void genpd_acquire_lock(struct generic_pm_domain *genpd)
{
DEFINE_WAIT(wait);
mutex_lock(&genpd->lock);
/*
* Wait for the domain to transition into either the active,
* or the power off state.
*/
for (;;) {
prepare_to_wait(&genpd->status_wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (genpd->status == GPD_STATE_ACTIVE
|| genpd->status == GPD_STATE_POWER_OFF)
break;
mutex_unlock(&genpd->lock);
schedule();
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
}
static void genpd_release_lock(struct generic_pm_domain *genpd)
{
mutex_unlock(&genpd->lock);
}
static void genpd_set_active(struct generic_pm_domain *genpd)
{
if (genpd->resume_count == 0)
genpd->status = GPD_STATE_ACTIVE;
}
/**
* __pm_genpd_poweron - Restore power to a given PM domain and its masters.
* @genpd: PM domain to power up.
*
* Restore power to @genpd and all of its masters so that it is possible to
* resume a device belonging to it.
*/
int __pm_genpd_poweron(struct generic_pm_domain *genpd)
__releases(&genpd->