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gem5 / arm / linux / 17208f1dec433b60eb9b427c17598adc431ab6de / . / drivers / base / power / domain.c
blob: e8ca5e2cf1e51e5ad17b08274a26e3251fdb0f93 [file] [log] [blame]
/*
* 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/delay.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/pm_qos.h>
#include <linux/pm_clock.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/suspend.h>
#include <linux/export.h>
#include "power.h"
#define GENPD_RETRY_MAX_MS 250 /* Approximate */
#define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \
({ \
type (*__routine)(struct device *__d); \
type __ret = (type)0; \
\
__routine = genpd->dev_ops.callback; \
if (__routine) { \
__ret = __routine(dev); \
} \
__ret; \
})
static LIST_HEAD(gpd_list);
static DEFINE_MUTEX(gpd_list_lock);
struct genpd_lock_ops {
void (*lock)(struct generic_pm_domain *genpd);
void (*lock_nested)(struct generic_pm_domain *genpd, int depth);
int (*lock_interruptible)(struct generic_pm_domain *genpd);
void (*unlock)(struct generic_pm_domain *genpd);
};
static void genpd_lock_mtx(struct generic_pm_domain *genpd)
{
mutex_lock(&genpd->mlock);
}
static void genpd_lock_nested_mtx(struct generic_pm_domain *genpd,
int depth)
{
mutex_lock_nested(&genpd->mlock, depth);
}
static int genpd_lock_interruptible_mtx(struct generic_pm_domain *genpd)
{
return mutex_lock_interruptible(&genpd->mlock);
}
static void genpd_unlock_mtx(struct generic_pm_domain *genpd)
{
return mutex_unlock(&genpd->mlock);
}
static const struct genpd_lock_ops genpd_mtx_ops = {
.lock = genpd_lock_mtx,
.lock_nested = genpd_lock_nested_mtx,
.lock_interruptible = genpd_lock_interruptible_mtx,
.unlock = genpd_unlock_mtx,
};
static void genpd_lock_spin(struct generic_pm_domain *genpd)
__acquires(&genpd->slock)
{
unsigned long flags;
spin_lock_irqsave(&genpd->slock, flags);
genpd->lock_flags = flags;
}
static void genpd_lock_nested_spin(struct generic_pm_domain *genpd,
int depth)
__acquires(&genpd->slock)
{
unsigned long flags;
spin_lock_irqsave_nested(&genpd->slock, flags, depth);
genpd->lock_flags = flags;
}
static int genpd_lock_interruptible_spin(struct generic_pm_domain *genpd)
__acquires(&genpd->slock)
{
unsigned long flags;
spin_lock_irqsave(&genpd->slock, flags);
genpd->lock_flags = flags;
return 0;
}
static void genpd_unlock_spin(struct generic_pm_domain *genpd)
__releases(&genpd->slock)
{
spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags);
}
static const struct genpd_lock_ops genpd_spin_ops = {
.lock = genpd_lock_spin,
.lock_nested = genpd_lock_nested_spin,
.lock_interruptible = genpd_lock_interruptible_spin,
.unlock = genpd_unlock_spin,
};
#define genpd_lock(p) p->lock_ops->lock(p)
#define genpd_lock_nested(p, d) p->lock_ops->lock_nested(p, d)
#define genpd_lock_interruptible(p) p->lock_ops->lock_interruptible(p)
#define genpd_unlock(p) p->lock_ops->unlock(p)
#define genpd_status_on(genpd) (genpd->status == GPD_STATE_ACTIVE)
#define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE)
#define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON)
static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
const struct generic_pm_domain *genpd)
{
bool ret;
ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd);
/*
* Warn once if an IRQ safe device is attached to a no sleep domain, as
* to indicate a suboptimal configuration for PM. For an always on
* domain this isn't case, thus don't warn.
*/
if (ret && !genpd_is_always_on(genpd))
dev_warn_once(dev, "PM domain %s will not be powered off\n",
genpd->name);
return ret;
}
/*
* Get the generic PM domain for a particular struct device.
* This validates the struct device pointer, the PM domain pointer,
* and checks that the PM domain pointer is a real generic PM domain.
* Any failure results in NULL being returned.
*/
static struct generic_pm_domain *genpd_lookup_dev(struct device *dev)
{
struct generic_pm_domain *genpd = NULL, *gpd;
if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain))
return NULL;
mutex_lock(&gpd_list_lock);
list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
if (&gpd->domain == dev->pm_domain) {
genpd = gpd;
break;
}
}
mutex_unlock(&gpd_list_lock);
return genpd;
}
/*
* This should only be used where we are certain that the pm_domain
* attached to the device is a genpd domain.
*/
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 int genpd_stop_dev(const struct generic_pm_domain *genpd,
struct device *dev)
{
return GENPD_DEV_CALLBACK(genpd, int, stop, dev);
}
static int genpd_start_dev(const struct generic_pm_domain *genpd,
struct device *dev)
{
return GENPD_DEV_CALLBACK(genpd, int, start, dev);
}
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();
}
#ifdef CONFIG_DEBUG_FS
static void genpd_update_accounting(struct generic_pm_domain *genpd)
{
ktime_t delta, now;
now = ktime_get();
delta = ktime_sub(now, genpd->accounting_time);
/*
* If genpd->status is active, it means we are just
* out of off and so update the idle time and vice
* versa.
*/
if (genpd->status == GPD_STATE_ACTIVE) {
int state_idx = genpd->state_idx;
genpd->states[state_idx].idle_time =
ktime_add(genpd->states[state_idx].idle_time, delta);
} else {
genpd->on_time = ktime_add(genpd->on_time, delta);
}
genpd->accounting_time = now;
}
#else
static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
#endif
static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
{
unsigned int state_idx = genpd->state_idx;
ktime_t time_start;
s64 elapsed_ns;
int ret;
if (!genpd->power_on)
return 0;
if (!timed)
return genpd->power_on(genpd);
time_start = ktime_get();
ret = genpd->power_on(genpd);
if (ret)
return ret;
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
return ret;
genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
genpd->max_off_time_changed = true;
pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
genpd->name, "on", elapsed_ns);
return ret;
}
static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
{
unsigned int state_idx = genpd->state_idx;
ktime_t time_start;
s64 elapsed_ns;
int ret;
if (!genpd->power_off)
return 0;
if (!timed)
return genpd->power_off(genpd);
time_start = ktime_get();
ret = genpd->power_off(genpd);
if (ret == -EBUSY)
return ret;
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns)
return ret;
genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
genpd->max_off_time_changed = true;
pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
genpd->name, "off", elapsed_ns);
return ret;
}
/**
* genpd_queue_power_off_work - Queue up the execution of genpd_power_off().
* @genpd: PM domain to power off.
*
* Queue up the execution of genpd_power_off() unless it's already been done
* before.
*/
static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
{
queue_work(pm_wq, &genpd->power_off_work);
}
/**
* genpd_power_off - Remove power from a given PM domain.
* @genpd: PM domain to power down.
* @one_dev_on: If invoked from genpd's ->runtime_suspend|resume() callback, the
* RPM status of the releated device is in an intermediate state, not yet turned
* into RPM_SUSPENDED. This means genpd_power_off() must allow one device to not
* be RPM_SUSPENDED, while it tries to power off the PM domain.
*
* If all of the @genpd's devices have been suspended and all of its subdomains
* have been powered down, remove power from @genpd.
*/
static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
unsigned int depth)
{
struct pm_domain_data *pdd;
struct gpd_link *link;
unsigned int not_suspended = 0;
/*
* Do not try to power off the domain in the following situations:
* (1) The domain is already in the "power off" state.
* (2) System suspend is in progress.
*/
if (!genpd_status_on(genpd) || genpd->prepared_count > 0)
return 0;
/*
* Abort power off for the PM domain in the following situations:
* (1) The domain is configured as always on.
* (2) When the domain has a subdomain being powered on.
*/
if (genpd_is_always_on(genpd) || atomic_read(&genpd->sd_count) > 0)
return -EBUSY;
list_for_each_entry(pdd, &genpd->dev_list, list_node) {
enum pm_qos_flags_status stat;
stat = dev_pm_qos_flags(pdd->dev,
PM_QOS_FLAG_NO_POWER_OFF
| PM_QOS_FLAG_REMOTE_WAKEUP);
if (stat > PM_QOS_FLAGS_NONE)
return -EBUSY;
/*
* Do not allow PM domain to be powered off, when an IRQ safe
* device is part of a non-IRQ safe domain.
*/
if (!pm_runtime_suspended(pdd->dev) ||
irq_safe_dev_in_no_sleep_domain(pdd->dev, genpd))
not_suspended++;
}
if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
return -EBUSY;
if (genpd->gov && genpd->gov->power_down_ok) {
if (!genpd->gov->power_down_ok(&genpd->domain))
return -EAGAIN;
}
if (genpd->power_off) {
int ret;
if (atomic_read(&genpd->sd_count) > 0)
return -EBUSY;
/*
* If sd_count > 0 at this point, one of the subdomains hasn't
* managed to call genpd_power_on() for the master yet after
* incrementing it. In that case genpd_power_on() will wait
* for us to drop the lock, so we can call .power_off() and let
* the genpd_power_on() restore power for us (this shouldn't
* happen very often).
*/
ret = _genpd_power_off(genpd, true);
if (ret)
return ret;
}
genpd->status = GPD_STATE_POWER_OFF;
genpd_update_accounting(genpd);
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_dec(link->master);
genpd_lock_nested(link->master, depth + 1);
genpd_power_off(link->master, false, depth + 1);
genpd_unlock(link->master);
}
return 0;
}
/**
* genpd_power_on - Restore power to a given PM domain and its masters.
* @genpd: PM domain to power up.
* @depth: nesting count for lockdep.
*
* Restore power to @genpd and all of its masters so that it is possible to
* resume a device belonging to it.
*/
static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth)
{
struct gpd_link *link;
int ret = 0;
if (genpd_status_on(genpd))
return 0;
/*
* The list is guaranteed not to change while the loop below is being
* executed, unless one of the masters' .power_on() callbacks fiddles
* with it.
*/
list_for_each_entry(link, &genpd->slave_links, slave_node) {
struct generic_pm_domain *master = link->master;
genpd_sd_counter_inc(master);
genpd_lock_nested(master, depth + 1);
ret = genpd_power_on(master, depth + 1);
genpd_unlock(master);
if (ret) {
genpd_sd_counter_dec(master);
goto err;
}
}
ret = _genpd_power_on(genpd, true);
if (ret)
goto err;
genpd->status = GPD_STATE_ACTIVE;
genpd_update_accounting(genpd);
return 0;
err:
list_for_each_entry_continue_reverse(link,
&genpd->slave_links,
slave_node) {
genpd_sd_counter_dec(link->master);
genpd_lock_nested(link->master, depth + 1);
genpd_power_off(link->master, false, depth + 1);
genpd_unlock(link->master);
}
return ret;
}
static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
unsigned long val, void *ptr)
{
struct generic_pm_domain_data *gpd_data;
struct device *dev;
gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
dev = gpd_data->base.dev;
for (;;) {
struct generic_pm_domain *genpd;
struct pm_domain_data *pdd;
spin_lock_irq(&dev->power.lock);
pdd = dev->power.subsys_data ?
dev->power.subsys_data->domain_data : NULL;
if (pdd) {
to_gpd_data(pdd)->td.constraint_changed = true;
genpd = dev_to_genpd(dev);
} else {
genpd = ERR_PTR(-ENODATA);
}
spin_unlock_irq(&dev->power.lock);
if (!IS_ERR(genpd)) {
genpd_lock(genpd);
genpd->max_off_time_changed = true;
genpd_unlock(genpd);
}
dev = dev->parent;
if (!dev || dev->power.ignore_children)
break;
}
return NOTIFY_DONE;
}
/**
* genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
* @work: Work structure used for scheduling the execution of this function.
*/
static void genpd_power_off_work_fn(struct work_struct *work)
{
struct generic_pm_domain *genpd;
genpd = container_of(work, struct generic_pm_domain, power_off_work);
genpd_lock(genpd);
genpd_power_off(genpd, false, 0);
genpd_unlock(genpd);
}
/**
* __genpd_runtime_suspend - walk the hierarchy of ->runtime_suspend() callbacks
* @dev: Device to handle.
*/
static int __genpd_runtime_suspend(struct device *dev)
{
int (*cb)(struct device *__dev);
if (dev->type && dev->type->pm)
cb = dev->type->pm->runtime_suspend;
else if (dev->class && dev->class->pm)
cb = dev->class->pm->runtime_suspend;
else if (dev->bus && dev->bus->pm)
cb = dev->bus->pm->runtime_suspend;
else
cb = NULL;
if (!cb && dev->driver && dev->driver->pm)
cb = dev->driver->pm->runtime_suspend;
return cb ? cb(dev) : 0;
}
/**
* __genpd_runtime_resume - walk the hierarchy of ->runtime_resume() callbacks
* @dev: Device to handle.
*/
static int __genpd_runtime_resume(struct device *dev)
{
int (*cb)(struct device *__dev);
if (dev->type && dev->type->pm)
cb = dev->type->pm->runtime_resume;
else if (dev->class && dev->class->pm)
cb = dev->class->pm->runtime_resume;
else if (dev->bus && dev->bus->pm)
cb = dev->bus->pm->runtime_resume;
else
cb = NULL;
if (!cb && dev->driver && dev->driver->pm)
cb = dev->driver->pm->runtime_resume;
return cb ? cb(dev) : 0;
}
/**
* genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
* @dev: Device to suspend.
*
* Carry out a runtime suspend of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int genpd_runtime_suspend(struct device *dev)
{
struct generic_pm_domain *genpd;
bool (*suspend_ok)(struct device *__dev);
struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
bool runtime_pm = pm_runtime_enabled(dev);
ktime_t time_start;
s64 elapsed_ns;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* A runtime PM centric subsystem/driver may re-use the runtime PM
* callbacks for other purposes than runtime PM. In those scenarios
* runtime PM is disabled. Under these circumstances, we shall skip
* validating/measuring the PM QoS latency.
*/
suspend_ok = genpd->gov ? genpd->gov->suspend_ok : NULL;
if (runtime_pm && suspend_ok && !suspend_ok(dev))
return -EBUSY;
/* Measure suspend latency. */
time_start = 0;
if (runtime_pm)
time_start = ktime_get();
ret = __genpd_runtime_suspend(dev);
if (ret)
return ret;
ret = genpd_stop_dev(genpd, dev);
if (ret) {
__genpd_runtime_resume(dev);
return ret;
}
/* Update suspend latency value if the measured time exceeds it. */
if (runtime_pm) {
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
if (elapsed_ns > td->suspend_latency_ns) {
td->suspend_latency_ns = elapsed_ns;
dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
elapsed_ns);
genpd->max_off_time_changed = true;
td->constraint_changed = true;
}
}
/*
* If power.irq_safe is set, this routine may be run with
* IRQs disabled, so suspend only if the PM domain also is irq_safe.
*/
if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
return 0;
genpd_lock(genpd);
genpd_power_off(genpd, true, 0);
genpd_unlock(genpd);
return 0;
}
/**
* genpd_runtime_resume - Resume a device belonging to I/O PM domain.
* @dev: Device to resume.
*
* Carry out a runtime resume of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int genpd_runtime_resume(struct device *dev)
{
struct generic_pm_domain *genpd;
struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
bool runtime_pm = pm_runtime_enabled(dev);
ktime_t time_start;
s64 elapsed_ns;
int ret;
bool timed = true;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* As we don't power off a non IRQ safe domain, which holds
* an IRQ safe device, we don't need to restore power to it.
*/
if (irq_safe_dev_in_no_sleep_domain(dev, genpd)) {
timed = false;
goto out;
}
genpd_lock(genpd);
ret = genpd_power_on(genpd, 0);
genpd_unlock(genpd);
if (ret)
return ret;
out:
/* Measure resume latency. */
time_start = 0;
if (timed && runtime_pm)
time_start = ktime_get();
ret = genpd_start_dev(genpd, dev);
if (ret)
goto err_poweroff;
ret = __genpd_runtime_resume(dev);
if (ret)
goto err_stop;
/* Update resume latency value if the measured time exceeds it. */
if (timed && runtime_pm) {
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
if (elapsed_ns > td->resume_latency_ns) {
td->resume_latency_ns = elapsed_ns;
dev_dbg(dev, "resume latency exceeded, %lld ns\n",
elapsed_ns);
genpd->max_off_time_changed = true;
td->constraint_changed = true;
}
}
return 0;
err_stop:
genpd_stop_dev(genpd, dev);
err_poweroff:
if (!pm_runtime_is_irq_safe(dev) ||
(pm_runtime_is_irq_safe(dev) && genpd_is_irq_safe(genpd))) {
genpd_lock(genpd);
genpd_power_off(genpd, true, 0);
genpd_unlock(genpd);
}
return ret;
}
static bool pd_ignore_unused;
static int __init pd_ignore_unused_setup(char *__unused)
{
pd_ignore_unused = true;
return 1;
}
__setup("pd_ignore_unused", pd_ignore_unused_setup);
/**
* genpd_power_off_unused - Power off all PM domains with no devices in use.
*/
static int __init genpd_power_off_unused(void)
{
struct generic_pm_domain *genpd;
if (pd_ignore_unused) {
pr_warn("genpd: Not disabling unused power domains\n");
return 0;
}
mutex_lock(&gpd_list_lock);
list_for_each_entry(genpd, &gpd_list, gpd_list_node)
genpd_queue_power_off_work(genpd);
mutex_unlock(&gpd_list_lock);
return 0;
}
late_initcall(genpd_power_off_unused);
#if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM_GENERIC_DOMAINS_OF)
/**
* pm_genpd_present - Check if the given PM domain has been initialized.
* @genpd: PM domain to check.
*/
static bool pm_genpd_present(const struct generic_pm_domain *genpd)
{
const struct generic_pm_domain *gpd;
if (IS_ERR_OR_NULL(genpd))
return false;
list_for_each_entry(gpd, &gpd_list, gpd_list_node)
if (gpd == genpd)
return true;
return false;
}
#endif
#ifdef CONFIG_PM_SLEEP
static bool genpd_dev_active_wakeup(const struct generic_pm_domain *genpd,
struct device *dev)
{
return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
}
/**
* genpd_sync_power_off - Synchronously power off a PM domain and its masters.
* @genpd: PM domain to power off, if possible.
* @use_lock: use the lock.
* @depth: nesting count for lockdep.
*
* Check if the given PM domain can be powered off (during system suspend or
* hibernation) and do that if so. Also, in that case propagate to its masters.
*
* This function is only called in "noirq" and "syscore" stages of system power
* transitions. The "noirq" callbacks may be executed asynchronously, thus in
* these cases the lock must be held.
*/
static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
unsigned int depth)
{
struct gpd_link *link;
if (!genpd_status_on(genpd) || genpd_is_always_on(genpd))
return;
if (genpd->suspended_count != genpd->device_count
|| atomic_read(&genpd->sd_count) > 0)
return;
/* Choose the deepest state when suspending */
genpd->state_idx = genpd->state_count - 1;
if (_genpd_power_off(genpd, false))
return;
genpd->status = GPD_STATE_POWER_OFF;
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_dec(link->master);
if (use_lock)
genpd_lock_nested(link->master, depth + 1);
genpd_sync_power_off(link->master, use_lock, depth + 1);
if (use_lock)
genpd_unlock(link->master);
}
}
/**
* genpd_sync_power_on - Synchronously power on a PM domain and its masters.
* @genpd: PM domain to power on.
* @use_lock: use the lock.
* @depth: nesting count for lockdep.
*
* This function is only called in "noirq" and "syscore" stages of system power
* transitions. The "noirq" callbacks may be executed asynchronously, thus in
* these cases the lock must be held.
*/
static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
unsigned int depth)
{
struct gpd_link *link;
if (genpd_status_on(genpd))
return;
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_inc(link->master);
if (use_lock)
genpd_lock_nested(link->master, depth + 1);
genpd_sync_power_on(link->master, use_lock, depth + 1);
if (use_lock)
genpd_unlock(link->master);
}
_genpd_power_on(genpd, false);
genpd->status = GPD_STATE_ACTIVE;
}
/**
* resume_needed - Check whether to resume a device before system suspend.
* @dev: Device to check.
* @genpd: PM domain the device belongs to.
*
* There are two cases in which a device that can wake up the system from sleep
* states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
* to wake up the system and it has to remain active for this purpose while the
* system is in the sleep state and (2) if the device is not enabled to wake up
* the system from sleep states and it generally doesn't generate wakeup signals
* by itself (those signals are generated on its behalf by other parts of the
* system). In the latter case it may be necessary to reconfigure the device's
* wakeup settings during system suspend, because it may have been set up to
* signal remote wakeup from the system's working state as needed by runtime PM.
* Return 'true' in either of the above cases.
*/
static bool resume_needed(struct device *dev,
const struct generic_pm_domain *genpd)
{
bool active_wakeup;
if (!device_can_wakeup(dev))
return false;
active_wakeup = genpd_dev_active_wakeup(genpd, dev);
return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
}
/**
* pm_genpd_prepare - Start power transition of a device in a PM domain.
* @dev: Device to start the transition of.
*
* Start a power transition of a device (during a system-wide power transition)
* under the assumption that its pm_domain field points to the domain member of
* an object of type struct generic_pm_domain representing a PM domain
* consisting of I/O devices.
*/
static int pm_genpd_prepare(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* If a wakeup request is pending for the device, it should be woken up
* at this point and a system wakeup event should be reported if it's
* set up to wake up the system from sleep states.
*/
if (resume_needed(dev, genpd))
pm_runtime_resume(dev);
genpd_lock(genpd);
if (genpd->prepared_count++ == 0)
genpd->suspended_count = 0;
genpd_unlock(genpd);
ret = pm_generic_prepare(dev);
if (ret) {
genpd_lock(genpd);
genpd->prepared_count--;
genpd_unlock(genpd);
}
return ret;
}
/**
* genpd_finish_suspend - Completion of suspend or hibernation of device in an
* I/O pm domain.
* @dev: Device to suspend.
* @poweroff: Specifies if this is a poweroff_noirq or suspend_noirq callback.
*
* Stop the device and remove power from the domain if all devices in it have
* been stopped.
*/
static int genpd_finish_suspend(struct device *dev, bool poweroff)
{
struct generic_pm_domain *genpd;
int ret;
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))
return 0;
if (poweroff)
ret = pm_generic_poweroff_noirq(dev);
else
ret = pm_generic_suspend_noirq(dev);
if (ret)
return ret;
if (genpd->dev_ops.stop && genpd->dev_ops.start) {
ret = pm_runtime_force_suspend(dev);
if (ret)
return ret;
}
genpd_lock(genpd);
genpd->suspended_count++;
genpd_sync_power_off(genpd, true, 0);
genpd_unlock(genpd);
return 0;
}
/**
* pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
* @dev: Device to suspend.
*
* Stop the device and remove power from the domain if all devices in it have
* been stopped.
*/
static int pm_genpd_suspend_noirq(struct device *dev)
{
dev_dbg(dev, "%s()\n", __func__);
return genpd_finish_suspend(dev, false);
}
/**
* pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
* @dev: Device to resume.
*
* Restore power to the device's PM domain, if necessary, and start the device.
*/
static int pm_genpd_resume_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))
return 0;
genpd_lock(genpd);
genpd_sync_power_on(genpd, true, 0);
genpd->suspended_count--;
genpd_unlock(genpd);
if (genpd->dev_ops.stop && genpd->dev_ops.start)
ret = pm_runtime_force_resume(dev);
ret = pm_generic_resume_noirq(dev);
if (ret)
return ret;
return ret;
}
/**
* pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
* @dev: Device to freeze.
*
* Carry out a late freeze of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a power domain consisting of I/O
* devices.
*/
static int pm_genpd_freeze_noirq(struct device *dev)
{
const struct generic_pm_domain *genpd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
ret = pm_generic_freeze_noirq(dev);
if (ret)
return ret;
if (genpd->dev_ops.stop && genpd->dev_ops.start)
ret = pm_runtime_force_suspend(dev);
return ret;
}
/**
* pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
* @dev: Device to thaw.
*
* Start the device, unless power has been removed from the domain already
* before the system transition.
*/
static int pm_genpd_thaw_noirq(struct device *dev)
{
const struct generic_pm_domain *genpd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->dev_ops.stop && genpd->dev_ops.start) {
ret = pm_runtime_force_resume(dev);
if (ret)
return ret;
}
return pm_generic_thaw_noirq(dev);
}
/**
* pm_genpd_poweroff_noirq - Completion of hibernation of device in an
* I/O PM domain.
* @dev: Device to poweroff.
*
* Stop the device and remove power from the domain if all devices in it have
* been stopped.
*/
static int pm_genpd_poweroff_noirq(struct device *dev)
{
dev_dbg(dev, "%s()\n", __func__);
return genpd_finish_suspend(dev, true);
}
/**
* pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
* @dev: Device to resume.
*
* Make sure the domain will be in the same power state as before the
* hibernation the system is resuming from and start the device if necessary.
*/
static int pm_genpd_restore_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* At this point suspended_count == 0 means we are being run for the
* first time for the given domain in the present cycle.
*/
genpd_lock(genpd);
if (genpd->suspended_count++ == 0)
/*
* The boot kernel might put the domain into arbitrary state,
* so make it appear as powered off to genpd_sync_power_on(),
* so that it tries to power it on in case it was really off.
*/
genpd->status = GPD_STATE_POWER_OFF;
genpd_sync_power_on(genpd, true, 0);
genpd_unlock(genpd);
if (genpd->dev_ops.stop && genpd->dev_ops.start) {
ret = pm_runtime_force_resume(dev);
if (ret)
return ret;
}
return pm_generic_restore_noirq(dev);
}
/**
* pm_genpd_complete - Complete power transition of a device in a power domain.
* @dev: Device to complete the transition of.
*
* Complete a power transition of a device (during a system-wide power
* transition) under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static void pm_genpd_complete(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return;
pm_generic_complete(dev);
genpd_lock(genpd);
genpd->prepared_count--;
if (!genpd->prepared_count)
genpd_queue_power_off_work(genpd);
genpd_unlock(genpd);
}
/**
* genpd_syscore_switch - Switch power during system core suspend or resume.
* @dev: Device that normally is marked as "always on" to switch power for.
*
* This routine may only be called during the system core (syscore) suspend or
* resume phase for devices whose "always on" flags are set.
*/
static void genpd_syscore_switch(struct device *dev, bool suspend)
{
struct generic_pm_domain *genpd;
genpd = dev_to_genpd(dev);
if (!pm_genpd_present(genpd))
return;
if (suspend) {
genpd->suspended_count++;
genpd_sync_power_off(genpd, false, 0);
} else {
genpd_sync_power_on(genpd, false, 0);
genpd->suspended_count--;
}
}
void pm_genpd_syscore_poweroff(struct device *dev)
{
genpd_syscore_switch(dev, true);
}
EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
void pm_genpd_syscore_poweron(struct device *dev)
{
genpd_syscore_switch(dev, false);
}
EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
#else /* !CONFIG_PM_SLEEP */
#define pm_genpd_prepare NULL
#define pm_genpd_suspend_noirq NULL
#define pm_genpd_resume_noirq NULL
#define pm_genpd_freeze_noirq NULL
#define pm_genpd_thaw_noirq NULL
#define pm_genpd_poweroff_noirq NULL
#define pm_genpd_restore_noirq NULL
#define pm_genpd_complete NULL
#endif /* CONFIG_PM_SLEEP */
static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
struct generic_pm_domain *genpd,
struct gpd_timing_data *td)
{
struct generic_pm_domain_data *gpd_data;
int ret;
ret = dev_pm_get_subsys_data(dev);
if (ret)
return ERR_PTR(ret);
gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
if (!gpd_data) {
ret = -ENOMEM;
goto err_put;
}
if (td)
gpd_data->td = *td;
gpd_data->base.dev = dev;
gpd_data->td.constraint_changed = true;
gpd_data->td.effective_constraint_ns = -1;
gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
spin_lock_irq(&dev->power.lock);
if (dev->power.subsys_data->domain_data) {
ret = -EINVAL;
goto err_free;
}
dev->power.subsys_data->domain_data = &gpd_data->base;
spin_unlock_irq(&dev->power.lock);
return gpd_data;
err_free:
spin_unlock_irq(&dev->power.lock);
kfree(gpd_data);
err_put:
dev_pm_put_subsys_data(dev);
return ERR_PTR(ret);
}
static void genpd_free_dev_data(struct device *dev,
struct generic_pm_domain_data *gpd_data)
{
spin_lock_irq(&dev->power.lock);
dev->power.subsys_data->domain_data = NULL;
spin_unlock_irq(&dev->power.lock);
kfree(gpd_data);
dev_pm_put_subsys_data(dev);
}
static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
struct gpd_timing_data *td)
{
struct generic_pm_domain_data *gpd_data;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
return -EINVAL;
gpd_data = genpd_alloc_dev_data(dev, genpd, td);
if (IS_ERR(gpd_data))
return PTR_ERR(gpd_data);
genpd_lock(genpd);
if (genpd->prepared_count > 0) {
ret = -EAGAIN;
goto out;
}
ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
if (ret)
goto out;
dev_pm_domain_set(dev, &genpd->domain);
genpd->device_count++;
genpd->max_off_time_changed = true;
list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
out:
genpd_unlock(genpd);
if (ret)
genpd_free_dev_data(dev, gpd_data);
else
dev_pm_qos_add_notifier(dev, &gpd_data->nb);
return ret;
}
/**
* __pm_genpd_add_device - Add a device to an I/O PM domain.
* @genpd: PM domain to add the device to.
* @dev: Device to be added.
* @td: Set of PM QoS timing parameters to attach to the device.
*/
int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
struct gpd_timing_data *td)
{
int ret;
mutex_lock(&gpd_list_lock);
ret = genpd_add_device(genpd, dev, td);
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(__pm_genpd_add_device);
static int genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev)
{
struct generic_pm_domain_data *gpd_data;
struct pm_domain_data *pdd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
pdd = dev->power.subsys_data->domain_data;
gpd_data = to_gpd_data(pdd);
dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
genpd_lock(genpd);
if (genpd->prepared_count > 0) {
ret = -EAGAIN;
goto out;
}
genpd->device_count--;
genpd->max_off_time_changed = true;
if (genpd->detach_dev)
genpd->detach_dev(genpd, dev);
dev_pm_domain_set(dev, NULL);
list_del_init(&pdd->list_node);
genpd_unlock(genpd);
genpd_free_dev_data(dev, gpd_data);
return 0;
out:
genpd_unlock(genpd);
dev_pm_qos_add_notifier(dev, &gpd_data->nb);
return ret;
}
/**
* pm_genpd_remove_device - Remove a device from an I/O PM domain.
* @genpd: PM domain to remove the device from.
* @dev: Device to be removed.
*/
int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev)
{
if (!genpd || genpd != genpd_lookup_dev(dev))
return -EINVAL;
return genpd_remove_device(genpd, dev);
}
EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
static int genpd_add_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *subdomain)
{
struct gpd_link *link, *itr;
int ret = 0;
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
|| genpd == subdomain)
return -EINVAL;
/*
* If the domain can be powered on/off in an IRQ safe
* context, ensure that the subdomain can also be
* powered on/off in that context.
*/
if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
genpd->name, subdomain->name);
return -EINVAL;
}
link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link)
return -ENOMEM;
genpd_lock(subdomain);
genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
if (!genpd_status_on(genpd) && genpd_status_on(subdomain)) {
ret = -EINVAL;
goto out;
}
list_for_each_entry(itr, &genpd->master_links, master_node) {
if (itr->slave == subdomain && itr->master == genpd) {
ret = -EINVAL;
goto out;
}
}
link->master = genpd;
list_add_tail(&link->master_node, &genpd->master_links);
link->slave = subdomain;
list_add_tail(&link->slave_node, &subdomain->slave_links);
if (genpd_status_on(subdomain))
genpd_sd_counter_inc(genpd);
out:
genpd_unlock(genpd);
genpd_unlock(subdomain);
if (ret)
kfree(link);
return ret;
}
/**
* pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
* @genpd: Master PM domain to add the subdomain to.
* @subdomain: Subdomain to be added.
*/
int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *subdomain)
{
int ret;
mutex_lock(&gpd_list_lock);
ret = genpd_add_subdomain(genpd, subdomain);
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
/**
* pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
* @genpd: Master PM domain to remove the subdomain from.
* @subdomain: Subdomain to be removed.
*/
int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *subdomain)
{
struct gpd_link *l, *link;
int ret = -EINVAL;
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
return -EINVAL;
genpd_lock(subdomain);
genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
if (!list_empty(&subdomain->master_links) || subdomain->device_count) {
pr_warn("%s: unable to remove subdomain %s\n", genpd->name,
subdomain->name);
ret = -EBUSY;
goto out;
}
list_for_each_entry_safe(link, l, &genpd->master_links, master_node) {
if (link->slave != subdomain)
continue;
list_del(&link->master_node);
list_del(&link->slave_node);
kfree(link);
if (genpd_status_on(subdomain))
genpd_sd_counter_dec(genpd);
ret = 0;
break;
}
out:
genpd_unlock(genpd);
genpd_unlock(subdomain);
return ret;
}
EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
{
struct genpd_power_state *state;
state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return -ENOMEM;
genpd->states = state;
genpd->state_count = 1;
genpd->free = state;
return 0;
}
static void genpd_lock_init(struct generic_pm_domain *genpd)
{
if (genpd->flags & GENPD_FLAG_IRQ_SAFE) {
spin_lock_init(&genpd->slock);
genpd->lock_ops = &genpd_spin_ops;
} else {
mutex_init(&genpd->mlock);
genpd->lock_ops = &genpd_mtx_ops;
}
}
/**
* pm_genpd_init - Initialize a generic I/O PM domain object.
* @genpd: PM domain object to initialize.
* @gov: PM domain governor to associate with the domain (may be NULL).
* @is_off: Initial value of the domain's power_is_off field.
*
* Returns 0 on successful initialization, else a negative error code.
*/
int pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off)
{
int ret;
if (IS_ERR_OR_NULL(genpd))
return -EINVAL;
INIT_LIST_HEAD(&genpd->master_links);
INIT_LIST_HEAD(&genpd->slave_links);
INIT_LIST_HEAD(&genpd->dev_list);
genpd_lock_init(genpd);
genpd->gov = gov;
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
genpd->device_count = 0;
genpd->max_off_time_ns = -1;
genpd->max_off_time_changed = true;
genpd->provider = NULL;
genpd->has_provider = false;
genpd->accounting_time = ktime_get();
genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
genpd->domain.ops.runtime_resume = genpd_runtime_resume;
genpd->domain.ops.prepare = pm_genpd_prepare;
genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
genpd->domain.ops.poweroff_noirq = pm_genpd_poweroff_noirq;
genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
genpd->domain.ops.complete = pm_genpd_complete;
if (genpd->flags & GENPD_FLAG_PM_CLK) {
genpd->dev_ops.stop = pm_clk_suspend;
genpd->dev_ops.start = pm_clk_resume;
}
/* Always-on domains must be powered on at initialization. */
if (genpd_is_always_on(genpd) && !genpd_status_on(genpd))
return -EINVAL;
/* Use only one "off" state if there were no states declared */
if (genpd->state_count == 0) {
ret = genpd_set_default_power_state(genpd);
if (ret)
return ret;
}
mutex_lock(&gpd_list_lock);
list_add(&genpd->gpd_list_node, &gpd_list);
mutex_unlock(&gpd_list_lock);
return 0;
}
EXPORT_SYMBOL_GPL(pm_genpd_init);
static int genpd_remove(struct generic_pm_domain *genpd)
{
struct gpd_link *l, *link;
if (IS_ERR_OR_NULL(genpd))
return -EINVAL;
genpd_lock(genpd);
if (genpd->has_provider) {
genpd_unlock(genpd);
pr_err("Provider present, unable to remove %s\n", genpd->name);
return -EBUSY;
}
if (!list_empty(&genpd->master_links) || genpd->device_count) {
genpd_unlock(genpd);
pr_err("%s: unable to remove %s\n", __func__, genpd->name);
return -EBUSY;
}
list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) {
list_del(&link->master_node);
list_del(&link->slave_node);
kfree(link);
}
list_del(&genpd->gpd_list_node);
genpd_unlock(genpd);
cancel_work_sync(&genpd->power_off_work);
kfree(genpd->free);
pr_debug("%s: removed %s\n", __func__, genpd->name);
return 0;
}
/**
* pm_genpd_remove - Remove a generic I/O PM domain
* @genpd: Pointer to PM domain that is to be removed.
*
* To remove the PM domain, this function:
* - Removes the PM domain as a subdomain to any parent domains,
* if it was added.
* - Removes the PM domain from the list of registered PM domains.
*
* The PM domain will only be removed, if the associated provider has
* been removed, it is not a parent to any other PM domain and has no
* devices associated with it.
*/
int pm_genpd_remove(struct generic_pm_domain *genpd)
{
int ret;
mutex_lock(&gpd_list_lock);
ret = genpd_remove(genpd);
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(pm_genpd_remove);
#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
/*
* Device Tree based PM domain providers.
*
* The code below implements generic device tree based PM domain providers that
* bind device tree nodes with generic PM domains registered in the system.
*
* Any driver that registers generic PM domains and needs to support binding of
* devices to these domains is supposed to register a PM domain provider, which
* maps a PM domain specifier retrieved from the device tree to a PM domain.
*
* Two simple mapping functions have been provided for convenience:
* - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
* - genpd_xlate_onecell() for mapping of multiple PM domains per node by
* index.
*/
/**
* struct of_genpd_provider - PM domain provider registration structure
* @link: Entry in global list of PM domain providers
* @node: Pointer to device tree node of PM domain provider
* @xlate: Provider-specific xlate callback mapping a set of specifier cells
* into a PM domain.
* @data: context pointer to be passed into @xlate callback
*/
struct of_genpd_provider {
struct list_head link;
struct device_node *node;
genpd_xlate_t xlate;
void *data;
};
/* List of registered PM domain providers. */
static LIST_HEAD(of_genpd_providers);
/* Mutex to protect the list above. */
static DEFINE_MUTEX(of_genpd_mutex);
/**
* genpd_xlate_simple() - Xlate function for direct node-domain mapping
* @genpdspec: OF phandle args to map into a PM domain
* @data: xlate function private data - pointer to struct generic_pm_domain
*
* This is a generic xlate function that can be used to model PM domains that
* have their own device tree nodes. The private data of xlate function needs
* to be a valid pointer to struct generic_pm_domain.
*/
static struct generic_pm_domain *genpd_xlate_simple(
struct of_phandle_args *genpdspec,
void *data)
{
return data;
}
/**
* genpd_xlate_onecell() - Xlate function using a single index.
* @genpdspec: OF phandle args to map into a PM domain
* @data: xlate function private data - pointer to struct genpd_onecell_data
*
* This is a generic xlate function that can be used to model simple PM domain
* controllers that have one device tree node and provide multiple PM domains.
* A single cell is used as an index into an array of PM domains specified in
* the genpd_onecell_data struct when registering the provider.
*/
static struct generic_pm_domain *genpd_xlate_onecell(
struct of_phandle_args *genpdspec,
void *data)
{
struct genpd_onecell_data *genpd_data = data;
unsigned int idx = genpdspec->args[0];
if (genpdspec->args_count != 1)
return ERR_PTR(-EINVAL);
if (idx >= genpd_data->num_domains) {
pr_err("%s: invalid domain index %u\n", __func__, idx);
return ERR_PTR(-EINVAL);
}
if (!genpd_data->domains[idx])
return ERR_PTR(-ENOENT);
return genpd_data->domains[idx];
}
/**
* genpd_add_provider() - Register a PM domain provider for a node
* @np: Device node pointer associated with the PM domain provider.
* @xlate: Callback for decoding PM domain from phandle arguments.
* @data: Context pointer for @xlate callback.
*/
static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
void *data)
{
struct of_genpd_provider *cp;
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
if (!cp)
return -ENOMEM;
cp->node = of_node_get(np);
cp->data = data;
cp->xlate = xlate;
mutex_lock(&of_genpd_mutex);
list_add(&cp->link, &of_genpd_providers);
mutex_unlock(&of_genpd_mutex);
pr_debug("Added domain provider from %pOF\n", np);
return 0;
}
/**
* of_genpd_add_provider_simple() - Register a simple PM domain provider
* @np: Device node pointer associated with the PM domain provider.
* @genpd: Pointer to PM domain associated with the PM domain provider.
*/
int of_genpd_add_provider_simple(struct device_node *np,
struct generic_pm_domain *genpd)
{
int ret = -EINVAL;
if (!np || !genpd)
return -EINVAL;
mutex_lock(&gpd_list_lock);
if (pm_genpd_present(genpd)) {
ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
if (!ret) {
genpd->provider = &np->fwnode;
genpd->has_provider = true;
}
}
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple);
/**
* of_genpd_add_provider_onecell() - Register a onecell PM domain provider
* @np: Device node pointer associated with the PM domain provider.
* @data: Pointer to the data associated with the PM domain provider.
*/
int of_genpd_add_provider_onecell(struct device_node *np,
struct genpd_onecell_data *data)
{
unsigned int i;
int ret = -EINVAL;
if (!np || !data)
return -EINVAL;
mutex_lock(&gpd_list_lock);
if (!data->xlate)
data->xlate = genpd_xlate_onecell;
for (i = 0; i < data->num_domains; i++) {
if (!data->domains[i])
continue;
if (!pm_genpd_present(data->domains[i]))
goto error;
data->domains[i]->provider = &np->fwnode;
data->domains[i]->has_provider = true;
}
ret = genpd_add_provider(np, data->xlate, data);
if (ret < 0)
goto error;
mutex_unlock(&gpd_list_lock);
return 0;
error:
while (i--) {
if (!data->domains[i])
continue;
data->domains[i]->provider = NULL;
data->domains[i]->has_provider = false;
}
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
/**
* of_genpd_del_provider() - Remove a previously registered PM domain provider
* @np: Device node pointer associated with the PM domain provider
*/
void of_genpd_del_provider(struct device_node *np)
{
struct of_genpd_provider *cp, *tmp;
struct generic_pm_domain *gpd;
mutex_lock(&gpd_list_lock);
mutex_lock(&of_genpd_mutex);
list_for_each_entry_safe(cp, tmp, &of_genpd_providers, link) {
if (cp->node == np) {
/*
* For each PM domain associated with the
* provider, set the 'has_provider' to false
* so that the PM domain can be safely removed.
*/
list_for_each_entry(gpd, &gpd_list, gpd_list_node)
if (gpd->provider == &np->fwnode)
gpd->has_provider = false;
list_del(&cp->link);
of_node_put(cp->node);
kfree(cp);
break;
}
}
mutex_unlock(&of_genpd_mutex);
mutex_unlock(&gpd_list_lock);
}
EXPORT_SYMBOL_GPL(of_genpd_del_provider);
/**
* genpd_get_from_provider() - Look-up PM domain
* @genpdspec: OF phandle args to use for look-up
*
* Looks for a PM domain provider under the node specified by @genpdspec and if
* found, uses xlate function of the provider to map phandle args to a PM
* domain.
*
* Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
* on failure.
*/
static struct generic_pm_domain *genpd_get_from_provider(
struct of_phandle_args *genpdspec)
{
struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
struct of_genpd_provider *provider;
if (!genpdspec)
return ERR_PTR(-EINVAL);
mutex_lock(&of_genpd_mutex);
/* Check if we have such a provider in our array */
list_for_each_entry(provider, &of_genpd_providers, link) {
if (provider->node == genpdspec->np)
genpd = provider->xlate(genpdspec, provider->data);
if (!IS_ERR(genpd))
break;
}
mutex_unlock(&of_genpd_mutex);
return genpd;
}
/**
* of_genpd_add_device() - Add a device to an I/O PM domain
* @genpdspec: OF phandle args to use for look-up PM domain
* @dev: Device to be added.
*
* Looks-up an I/O PM domain based upon phandle args provided and adds
* the device to the PM domain. Returns a negative error code on failure.
*/
int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
mutex_lock(&gpd_list_lock);
genpd = genpd_get_from_provider(genpdspec);
if (IS_ERR(genpd)) {
ret = PTR_ERR(genpd);
goto out;
}
ret = genpd_add_device(genpd, dev, NULL);
out:
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(of_genpd_add_device);
/**
* of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
* @parent_spec: OF phandle args to use for parent PM domain look-up
* @subdomain_spec: OF phandle args to use for subdomain look-up
*
* Looks-up a parent PM domain and subdomain based upon phandle args
* provided and adds the subdomain to the parent PM domain. Returns a
* negative error code on failure.
*/
int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
struct of_phandle_args *subdomain_spec)
{
struct generic_pm_domain *parent, *subdomain;
int ret;
mutex_lock(&gpd_list_lock);
parent = genpd_get_from_provider(parent_spec);
if (IS_ERR(parent)) {
ret = PTR_ERR(parent);
goto out;
}
subdomain = genpd_get_from_provider(subdomain_spec);
if (IS_ERR(subdomain)) {
ret = PTR_ERR(subdomain);
goto out;
}
ret = genpd_add_subdomain(parent, subdomain);
out:
mutex_unlock(&gpd_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
/**
* of_genpd_remove_last - Remove the last PM domain registered for a provider
* @provider: Pointer to device structure associated with provider
*
* Find the last PM domain that was added by a particular provider and
* remove this PM domain from the list of PM domains. The provider is
* identified by the 'provider' device structure that is passed. The PM
* domain will only be removed, if the provider associated with domain
* has been removed.
*
* Returns a valid pointer to struct generic_pm_domain on success or
* ERR_PTR() on failure.
*/
struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
{
struct generic_pm_domain *gpd, *tmp, *genpd = ERR_PTR(-ENOENT);
int ret;
if (IS_ERR_OR_NULL(np))
return ERR_PTR(-EINVAL);
mutex_lock(&gpd_list_lock);
list_for_each_entry_safe(gpd, tmp, &gpd_list, gpd_list_node) {
if (gpd->provider == &np->fwnode) {
ret = genpd_remove(gpd);
genpd = ret ? ERR_PTR(ret) : gpd;
break;
}
}
mutex_unlock(&gpd_list_lock);
return genpd;
}
EXPORT_SYMBOL_GPL(of_genpd_remove_last);
/**
* genpd_dev_pm_detach - Detach a device from its PM domain.
* @dev: Device to detach.
* @power_off: Currently not used
*
* Try to locate a corresponding generic PM domain, which the device was
* attached to previously. If such is found, the device is detached from it.
*/
static void genpd_dev_pm_detach(struct device *dev, bool power_off)
{
struct generic_pm_domain *pd;
unsigned int i;
int ret = 0;
pd = dev_to_genpd(dev);
if (IS_ERR(pd))
return;
dev_dbg(dev, "removing from PM domain %s\n", pd->name);
for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
ret = genpd_remove_device(pd, dev);
if (ret != -EAGAIN)
break;
mdelay(i);
cond_resched();
}
if (ret < 0) {
dev_err(dev, "failed to remove from PM domain %s: %d",
pd->name, ret);
return;
}
/* Check if PM domain can be powered off after removing this device. */
genpd_queue_power_off_work(pd);
}
static void genpd_dev_pm_sync(struct device *dev)
{
struct generic_pm_domain *pd;
pd = dev_to_genpd(dev);
if (IS_ERR(pd))
return;
genpd_queue_power_off_work(pd);
}
/**
* genpd_dev_pm_attach - Attach a device to its PM domain using DT.
* @dev: Device to attach.
*
* Parse device's OF node to find a PM domain specifier. If such is found,
* attaches the device to retrieved pm_domain ops.
*
* Both generic and legacy Samsung-specific DT bindings are supported to keep
* backwards compatibility with existing DTBs.
*
* Returns 0 on successfully attached PM domain or negative error code. Note
* that if a power-domain exists for the device, but it cannot be found or
* turned on, then return -EPROBE_DEFER to ensure that the device is not
* probed and to re-try again later.
*/
int genpd_dev_pm_attach(struct device *dev)
{
struct of_phandle_args pd_args;
struct generic_pm_domain *pd;
unsigned int i;
int ret;
if (!dev->of_node)
return -ENODEV;
if (dev->pm_domain)
return -EEXIST;
ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
"#power-domain-cells", 0, &pd_args);
if (ret < 0) {
if (ret != -ENOENT)
return ret;
/*
* Try legacy Samsung-specific bindings
* (for backwards compatibility of DT ABI)
*/
pd_args.args_count = 0;
pd_args.np = of_parse_phandle(dev->of_node,
"samsung,power-domain", 0);
if (!pd_args.np)
return -ENOENT;
}
mutex_lock(&gpd_list_lock);
pd = genpd_get_from_provider(&pd_args);
of_node_put(pd_args.np);
if (IS_ERR(pd)) {
mutex_unlock(&gpd_list_lock);
dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
__func__, PTR_ERR(pd));
return -EPROBE_DEFER;
}
dev_dbg(dev, "adding to PM domain %s\n", pd->name);
for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
ret = genpd_add_device(pd, dev, NULL);
if (ret != -EAGAIN)
break;
mdelay(i);
cond_resched();
}
mutex_unlock(&gpd_list_lock);
if (ret < 0) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "failed to add to PM domain %s: %d",
pd->name, ret);
goto out;
}
dev->pm_domain->detach = genpd_dev_pm_detach;
dev->pm_domain->sync = genpd_dev_pm_sync;
genpd_lock(pd);
ret = genpd_power_on(pd, 0);
genpd_unlock(pd);
out:
return ret ? -EPROBE_DEFER : 0;
}
EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
static const struct of_device_id idle_state_match[] = {
{ .compatible = "domain-idle-state", },
{ }
};
static int genpd_parse_state(struct genpd_power_state *genpd_state,
struct device_node *state_node)
{
int err;
u32 residency;
u32 entry_latency, exit_latency;
err = of_property_read_u32(state_node, "entry-latency-us",
&entry_latency);
if (err) {
pr_debug(" * %pOF missing entry-latency-us property\n",
state_node);
return -EINVAL;
}
err = of_property_read_u32(state_node, "exit-latency-us",
&exit_latency);
if (err) {
pr_debug(" * %pOF missing exit-latency-us property\n",
state_node);
return -EINVAL;
}
err = of_property_read_u32(state_node, "min-residency-us", &residency);
if (!err)
genpd_state->residency_ns = 1000 * residency;
genpd_state->power_on_latency_ns = 1000 * exit_latency;
genpd_state->power_off_latency_ns = 1000 * entry_latency;
genpd_state->fwnode = &state_node->fwnode;
return 0;
}
/**
* of_genpd_parse_idle_states: Return array of idle states for the genpd.
*
* @dn: The genpd device node
* @states: The pointer to which the state array will be saved.
* @n: The count of elements in the array returned from this function.
*
* Returns the device states parsed from the OF node. The memory for the states
* is allocated by this function and is the responsibility of the caller to
* free the memory after use.
*/
int of_genpd_parse_idle_states(struct device_node *dn,
struct genpd_power_state **states, int *n)
{
struct genpd_power_state *st;
struct device_node *np;
int i = 0;
int err, ret;
int count;
struct of_phandle_iterator it;
const struct of_device_id *match_id;
count = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
if (count <= 0)
return -EINVAL;
st = kcalloc(count, sizeof(*st), GFP_KERNEL);
if (!st)
return -ENOMEM;
/* Loop over the phandles until all the requested entry is found */
of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) {
np = it.node;
match_id = of_match_node(idle_state_match, np);
if (!match_id)
continue;
ret = genpd_parse_state(&st[i++], np);
if (ret) {
pr_err
("Parsing idle state node %pOF failed with err %d\n",
np, ret);
of_node_put(np);
kfree(st);
return ret;
}
}
*n = i;
if (!i)
kfree(st);
else
*states = st;
return 0;
}
EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
/*** debugfs support ***/
#ifdef CONFIG_DEBUG_FS
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/kobject.h>
static struct dentry *pm_genpd_debugfs_dir;
/*
* TODO: This function is a slightly modified version of rtpm_status_show
* from sysfs.c, so generalize it.
*/
static void rtpm_status_str(struct seq_file *s, struct device *dev)
{
static const char * const status_lookup[] = {
[RPM_ACTIVE] = "active",
[RPM_RESUMING] = "resuming",
[RPM_SUSPENDED] = "suspended",
[RPM_SUSPENDING] = "suspending"
};
const char *p = "";
if (dev->power.runtime_error)
p = "error";
else if (dev->power.disable_depth)
p = "unsupported";
else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
p = status_lookup[dev->power.runtime_status];
else
WARN_ON(1);
seq_puts(s, p);
}
static int pm_genpd_summary_one(struct seq_file *s,
struct generic_pm_domain *genpd)
{
static const char * const status_lookup[] = {
[GPD_STATE_ACTIVE] = "on",
[GPD_STATE_POWER_OFF] = "off"
};
struct pm_domain_data *pm_data;
const char *kobj_path;
struct gpd_link *link;
char state[16];
int ret;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup)))
goto exit;
if (!genpd_status_on(genpd))
snprintf(state, sizeof(state), "%s-%u",
status_lookup[genpd->status], genpd->state_idx);
else
snprintf(state, sizeof(state), "%s",
status_lookup[genpd->status]);
seq_printf(s, "%-30s %-15s ", genpd->name, state);
/*
* Modifications on the list require holding locks on both
* master and slave, so we are safe.
* Also genpd->name is immutable.
*/
list_for_each_entry(link, &genpd->master_links, master_node) {
seq_printf(s, "%s", link->slave->name);
if (!list_is_last(&link->master_node, &genpd->master_links))
seq_puts(s, ", ");
}
list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
kobj_path = kobject_get_path(&pm_data->dev->kobj,
genpd_is_irq_safe(genpd) ?
GFP_ATOMIC : GFP_KERNEL);
if (kobj_path == NULL)
continue;
seq_printf(s, "\n %-50s ", kobj_path);
rtpm_status_str(s, pm_data->dev);
kfree(kobj_path);
}
seq_puts(s, "\n");
exit:
genpd_unlock(genpd);
return 0;
}
static int genpd_summary_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd;
int ret = 0;
seq_puts(s, "domain status slaves\n");
seq_puts(s, " /device runtime status\n");
seq_puts(s, "----------------------------------------------------------------------\n");
ret = mutex_lock_interruptible(&gpd_list_lock);
if (ret)
return -ERESTARTSYS;
list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
ret = pm_genpd_summary_one(s, genpd);
if (ret)
break;
}
mutex_unlock(&gpd_list_lock);
return ret;
}
static int genpd_status_show(struct seq_file *s, void *data)
{
static const char * const status_lookup[] = {
[GPD_STATE_ACTIVE] = "on",
[GPD_STATE_POWER_OFF] = "off"
};
struct generic_pm_domain *genpd = s->private;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
if (WARN_ON_ONCE(genpd->status >= ARRAY_SIZE(status_lookup)))
goto exit;
if (genpd->status == GPD_STATE_POWER_OFF)
seq_printf(s, "%s-%u\n", status_lookup[genpd->status],
genpd->state_idx);
else
seq_printf(s, "%s\n", status_lookup[genpd->status]);
exit:
genpd_unlock(genpd);
return ret;
}
static int genpd_sub_domains_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
struct gpd_link *link;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
list_for_each_entry(link, &genpd->master_links, master_node)
seq_printf(s, "%s\n", link->slave->name);
genpd_unlock(genpd);
return ret;
}
static int genpd_idle_states_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
unsigned int i;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
seq_puts(s, "State Time Spent(ms)\n");
for (i = 0; i < genpd->state_count; i++) {
ktime_t delta = 0;
s64 msecs;
if ((genpd->status == GPD_STATE_POWER_OFF) &&
(genpd->state_idx == i))
delta = ktime_sub(ktime_get(), genpd->accounting_time);
msecs = ktime_to_ms(
ktime_add(genpd->states[i].idle_time, delta));
seq_printf(s, "S%-13i %lld\n", i, msecs);
}
genpd_unlock(genpd);
return ret;
}
static int genpd_active_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
ktime_t delta = 0;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
if (genpd->status == GPD_STATE_ACTIVE)
delta = ktime_sub(ktime_get(), genpd->accounting_time);
seq_printf(s, "%lld ms\n", ktime_to_ms(
ktime_add(genpd->on_time, delta)));
genpd_unlock(genpd);
return ret;
}
static int genpd_total_idle_time_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
ktime_t delta = 0, total = 0;
unsigned int i;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
for (i = 0; i < genpd->state_count; i++) {
if ((genpd->status == GPD_STATE_POWER_OFF) &&
(genpd->state_idx == i))
delta = ktime_sub(ktime_get(), genpd->accounting_time);
total = ktime_add(total, genpd->states[i].idle_time);
}
total = ktime_add(total, delta);
seq_printf(s, "%lld ms\n", ktime_to_ms(total));
genpd_unlock(genpd);
return ret;
}
static int genpd_devices_show(struct seq_file *s, void *data)
{
struct generic_pm_domain *genpd = s->private;
struct pm_domain_data *pm_data;
const char *kobj_path;
int ret = 0;
ret = genpd_lock_interruptible(genpd);
if (ret)
return -ERESTARTSYS;
list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
kobj_path = kobject_get_path(&pm_data->dev->kobj,
genpd_is_irq_safe(genpd) ?
GFP_ATOMIC : GFP_KERNEL);
if (kobj_path == NULL)
continue;
seq_printf(s, "%s\n", kobj_path);
kfree(kobj_path);
}
genpd_unlock(genpd);
return ret;
}
#define define_genpd_open_function(name) \
static int genpd_##name##_open(struct inode *inode, struct file *file) \
{ \
return single_open(file, genpd_##name##_show, inode->i_private); \
}
define_genpd_open_function(summary);
define_genpd_open_function(status);
define_genpd_open_function(sub_domains);
define_genpd_open_function(idle_states);
define_genpd_open_function(active_time);
define_genpd_open_function(total_idle_time);
define_genpd_open_function(devices);
#define define_genpd_debugfs_fops(name) \
static const struct file_operations genpd_##name##_fops = { \
.open = genpd_##name##_open, \
.read = seq_read, \
.llseek = seq_lseek, \
.release = single_release, \
}
define_genpd_debugfs_fops(summary);
define_genpd_debugfs_fops(status);
define_genpd_debugfs_fops(sub_domains);
define_genpd_debugfs_fops(idle_states);
define_genpd_debugfs_fops(active_time);
define_genpd_debugfs_fops(total_idle_time);
define_genpd_debugfs_fops(devices);
static int __init pm_genpd_debug_init(void)
{
struct dentry *d;
struct generic_pm_domain *genpd;
pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
if (!pm_genpd_debugfs_dir)
return -ENOMEM;
d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
pm_genpd_debugfs_dir, NULL, &genpd_summary_fops);
if (!d)
return -ENOMEM;
list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
d = debugfs_create_dir(genpd->name, pm_genpd_debugfs_dir);
if (!d)
return -ENOMEM;
debugfs_create_file("current_state", 0444,
d, genpd, &genpd_status_fops);
debugfs_create_file("sub_domains", 0444,
d, genpd, &genpd_sub_domains_fops);
debugfs_create_file("idle_states", 0444,
d, genpd, &genpd_idle_states_fops);
debugfs_create_file("active_time", 0444,
d, genpd, &genpd_active_time_fops);
debugfs_create_file("total_idle_time", 0444,
d, genpd, &genpd_total_idle_time_fops);
debugfs_create_file("devices", 0444,
d, genpd, &genpd_devices_fops);
}
return 0;
}
late_initcall(pm_genpd_debug_init);
static void __exit pm_genpd_debug_exit(void)
{
debugfs_remove_recursive(pm_genpd_debugfs_dir);
}
__exitcall(pm_genpd_debug_exit);
#endif /* CONFIG_DEBUG_FS */