android_kernel_xiaomi_sm8350/drivers/base/power/sysfs.c
Alan Stern 15bcb91d7e PM / Runtime: Implement autosuspend support
This patch (as1427) implements the "autosuspend" facility for runtime
PM.  A few new fields are added to the dev_pm_info structure and
several new PM helper functions are defined, for telling the PM core
whether or not a device uses autosuspend, for setting the autosuspend
delay, and for marking periods of device activity.

Drivers that do not want to use autosuspend can continue using the
same helper functions as before; their behavior will not change.  In
addition, drivers supporting autosuspend can also call the old helper
functions to get the old behavior.

The details are all explained in Documentation/power/runtime_pm.txt
and Documentation/ABI/testing/sysfs-devices-power.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17 01:57:48 +02:00

515 lines
14 KiB
C

/*
* drivers/base/power/sysfs.c - sysfs entries for device PM
*/
#include <linux/device.h>
#include <linux/string.h>
#include <linux/pm_runtime.h>
#include <asm/atomic.h>
#include <linux/jiffies.h>
#include "power.h"
/*
* control - Report/change current runtime PM setting of the device
*
* Runtime power management of a device can be blocked with the help of
* this attribute. All devices have one of the following two values for
* the power/control file:
*
* + "auto\n" to allow the device to be power managed at run time;
* + "on\n" to prevent the device from being power managed at run time;
*
* The default for all devices is "auto", which means that devices may be
* subject to automatic power management, depending on their drivers.
* Changing this attribute to "on" prevents the driver from power managing
* the device at run time. Doing that while the device is suspended causes
* it to be woken up.
*
* wakeup - Report/change current wakeup option for device
*
* Some devices support "wakeup" events, which are hardware signals
* used to activate devices from suspended or low power states. Such
* devices have one of three values for the sysfs power/wakeup file:
*
* + "enabled\n" to issue the events;
* + "disabled\n" not to do so; or
* + "\n" for temporary or permanent inability to issue wakeup.
*
* (For example, unconfigured USB devices can't issue wakeups.)
*
* Familiar examples of devices that can issue wakeup events include
* keyboards and mice (both PS2 and USB styles), power buttons, modems,
* "Wake-On-LAN" Ethernet links, GPIO lines, and more. Some events
* will wake the entire system from a suspend state; others may just
* wake up the device (if the system as a whole is already active).
* Some wakeup events use normal IRQ lines; other use special out
* of band signaling.
*
* It is the responsibility of device drivers to enable (or disable)
* wakeup signaling as part of changing device power states, respecting
* the policy choices provided through the driver model.
*
* Devices may not be able to generate wakeup events from all power
* states. Also, the events may be ignored in some configurations;
* for example, they might need help from other devices that aren't
* active, or which may have wakeup disabled. Some drivers rely on
* wakeup events internally (unless they are disabled), keeping
* their hardware in low power modes whenever they're unused. This
* saves runtime power, without requiring system-wide sleep states.
*
* async - Report/change current async suspend setting for the device
*
* Asynchronous suspend and resume of the device during system-wide power
* state transitions can be enabled by writing "enabled" to this file.
* Analogously, if "disabled" is written to this file, the device will be
* suspended and resumed synchronously.
*
* All devices have one of the following two values for power/async:
*
* + "enabled\n" to permit the asynchronous suspend/resume of the device;
* + "disabled\n" to forbid it;
*
* NOTE: It generally is unsafe to permit the asynchronous suspend/resume
* of a device unless it is certain that all of the PM dependencies of the
* device are known to the PM core. However, for some devices this
* attribute is set to "enabled" by bus type code or device drivers and in
* that cases it should be safe to leave the default value.
*
* autosuspend_delay_ms - Report/change a device's autosuspend_delay value
*
* Some drivers don't want to carry out a runtime suspend as soon as a
* device becomes idle; they want it always to remain idle for some period
* of time before suspending it. This period is the autosuspend_delay
* value (expressed in milliseconds) and it can be controlled by the user.
* If the value is negative then the device will never be runtime
* suspended.
*
* NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
* value are used only if the driver calls pm_runtime_use_autosuspend().
*
* wakeup_count - Report the number of wakeup events related to the device
*/
static const char enabled[] = "enabled";
static const char disabled[] = "disabled";
const char power_group_name[] = "power";
EXPORT_SYMBOL_GPL(power_group_name);
#ifdef CONFIG_PM_RUNTIME
static const char ctrl_auto[] = "auto";
static const char ctrl_on[] = "on";
static ssize_t control_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n",
dev->power.runtime_auto ? ctrl_auto : ctrl_on);
}
static ssize_t control_store(struct device * dev, struct device_attribute *attr,
const char * buf, size_t n)
{
char *cp;
int len = n;
cp = memchr(buf, '\n', n);
if (cp)
len = cp - buf;
if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
pm_runtime_allow(dev);
else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
pm_runtime_forbid(dev);
else
return -EINVAL;
return n;
}
static DEVICE_ATTR(control, 0644, control_show, control_store);
static ssize_t rtpm_active_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
spin_lock_irq(&dev->power.lock);
update_pm_runtime_accounting(dev);
ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
spin_unlock_irq(&dev->power.lock);
return ret;
}
static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
static ssize_t rtpm_suspended_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
spin_lock_irq(&dev->power.lock);
update_pm_runtime_accounting(dev);
ret = sprintf(buf, "%i\n",
jiffies_to_msecs(dev->power.suspended_jiffies));
spin_unlock_irq(&dev->power.lock);
return ret;
}
static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
static ssize_t rtpm_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const char *p;
if (dev->power.runtime_error) {
p = "error\n";
} else if (dev->power.disable_depth) {
p = "unsupported\n";
} else {
switch (dev->power.runtime_status) {
case RPM_SUSPENDED:
p = "suspended\n";
break;
case RPM_SUSPENDING:
p = "suspending\n";
break;
case RPM_RESUMING:
p = "resuming\n";
break;
case RPM_ACTIVE:
p = "active\n";
break;
default:
return -EIO;
}
}
return sprintf(buf, p);
}
static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
static ssize_t autosuspend_delay_ms_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if (!dev->power.use_autosuspend)
return -EIO;
return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
}
static ssize_t autosuspend_delay_ms_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t n)
{
long delay;
if (!dev->power.use_autosuspend)
return -EIO;
if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
return -EINVAL;
pm_runtime_set_autosuspend_delay(dev, delay);
return n;
}
static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
autosuspend_delay_ms_store);
#endif
static ssize_t
wake_show(struct device * dev, struct device_attribute *attr, char * buf)
{
return sprintf(buf, "%s\n", device_can_wakeup(dev)
? (device_may_wakeup(dev) ? enabled : disabled)
: "");
}
static ssize_t
wake_store(struct device * dev, struct device_attribute *attr,
const char * buf, size_t n)
{
char *cp;
int len = n;
if (!device_can_wakeup(dev))
return -EINVAL;
cp = memchr(buf, '\n', n);
if (cp)
len = cp - buf;
if (len == sizeof enabled - 1
&& strncmp(buf, enabled, sizeof enabled - 1) == 0)
device_set_wakeup_enable(dev, 1);
else if (len == sizeof disabled - 1
&& strncmp(buf, disabled, sizeof disabled - 1) == 0)
device_set_wakeup_enable(dev, 0);
else
return -EINVAL;
return n;
}
static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
#ifdef CONFIG_PM_SLEEP
static ssize_t wakeup_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->event_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
static ssize_t wakeup_active_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->active_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
static ssize_t wakeup_hit_count_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long count = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
count = dev->power.wakeup->hit_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_count_show, NULL);
static ssize_t wakeup_active_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned int active = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
active = dev->power.wakeup->active;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
static ssize_t wakeup_total_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->total_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
static ssize_t wakeup_max_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->max_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
static ssize_t wakeup_last_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
s64 msec = 0;
bool enabled = false;
spin_lock_irq(&dev->power.lock);
if (dev->power.wakeup) {
msec = ktime_to_ms(dev->power.wakeup->last_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_RUNTIME
static ssize_t rtpm_usagecount_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
}
static ssize_t rtpm_children_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", dev->power.ignore_children ?
0 : atomic_read(&dev->power.child_count));
}
static ssize_t rtpm_enabled_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
return sprintf(buf, "disabled & forbidden\n");
else if (dev->power.disable_depth)
return sprintf(buf, "disabled\n");
else if (dev->power.runtime_auto == false)
return sprintf(buf, "forbidden\n");
return sprintf(buf, "enabled\n");
}
static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
#endif
static ssize_t async_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n",
device_async_suspend_enabled(dev) ? enabled : disabled);
}
static ssize_t async_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t n)
{
char *cp;
int len = n;
cp = memchr(buf, '\n', n);
if (cp)
len = cp - buf;
if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0)
device_enable_async_suspend(dev);
else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0)
device_disable_async_suspend(dev);
else
return -EINVAL;
return n;
}
static DEVICE_ATTR(async, 0644, async_show, async_store);
#endif /* CONFIG_PM_ADVANCED_DEBUG */
static struct attribute * power_attrs[] = {
&dev_attr_wakeup.attr,
#ifdef CONFIG_PM_SLEEP
&dev_attr_wakeup_count.attr,
&dev_attr_wakeup_active_count.attr,
&dev_attr_wakeup_hit_count.attr,
&dev_attr_wakeup_active.attr,
&dev_attr_wakeup_total_time_ms.attr,
&dev_attr_wakeup_max_time_ms.attr,
&dev_attr_wakeup_last_time_ms.attr,
#endif
#ifdef CONFIG_PM_ADVANCED_DEBUG
&dev_attr_async.attr,
#ifdef CONFIG_PM_RUNTIME
&dev_attr_runtime_status.attr,
&dev_attr_runtime_usage.attr,
&dev_attr_runtime_active_kids.attr,
&dev_attr_runtime_enabled.attr,
#endif
#endif
NULL,
};
static struct attribute_group pm_attr_group = {
.name = power_group_name,
.attrs = power_attrs,
};
#ifdef CONFIG_PM_RUNTIME
static struct attribute *runtime_attrs[] = {
#ifndef CONFIG_PM_ADVANCED_DEBUG
&dev_attr_runtime_status.attr,
#endif
&dev_attr_control.attr,
&dev_attr_runtime_suspended_time.attr,
&dev_attr_runtime_active_time.attr,
&dev_attr_autosuspend_delay_ms.attr,
NULL,
};
static struct attribute_group pm_runtime_attr_group = {
.name = power_group_name,
.attrs = runtime_attrs,
};
int dpm_sysfs_add(struct device *dev)
{
int rc;
rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
if (rc == 0 && !dev->power.no_callbacks) {
rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
if (rc)
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
return rc;
}
void rpm_sysfs_remove(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
}
void dpm_sysfs_remove(struct device *dev)
{
rpm_sysfs_remove(dev);
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
#else /* CONFIG_PM_RUNTIME */
int dpm_sysfs_add(struct device * dev)
{
return sysfs_create_group(&dev->kobj, &pm_attr_group);
}
void dpm_sysfs_remove(struct device * dev)
{
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
#endif