/* * drivers/base/power/sysfs.c - sysfs entries for device PM */ #include <linux/device.h> #include <linux/string.h> #include <linux/export.h> #include <linux/pm_qos.h> #include <linux/pm_runtime.h> #include <linux/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 */ const char power_group_name[] = "power"; EXPORT_SYMBOL_GPL(power_group_name); 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) { device_lock(dev); if (sysfs_streq(buf, ctrl_auto)) pm_runtime_allow(dev); else if (sysfs_streq(buf, ctrl_on)) pm_runtime_forbid(dev); else n = -EINVAL; device_unlock(dev); return n; } static DEVICE_ATTR_RW(control); static ssize_t runtime_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_RO(runtime_active_time); static ssize_t runtime_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_RO(runtime_suspended_time); static ssize_t runtime_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_RO(runtime_status); 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 (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay) return -EINVAL; device_lock(dev); pm_runtime_set_autosuspend_delay(dev, delay); device_unlock(dev); return n; } static DEVICE_ATTR_RW(autosuspend_delay_ms); static ssize_t pm_qos_resume_latency_us_show(struct device *dev, struct device_attribute *attr, char *buf) { s32 value = dev_pm_qos_requested_resume_latency(dev); if (value == 0) return sprintf(buf, "n/a\n"); if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) value = 0; return sprintf(buf, "%d\n", value); } static ssize_t pm_qos_resume_latency_us_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { s32 value; int ret; if (!kstrtos32(buf, 0, &value)) { /* * Prevent users from writing negative or "no constraint" values * directly. */ if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) return -EINVAL; if (value == 0) value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; } else if (sysfs_streq(buf, "n/a")) { value = 0; } else { return -EINVAL; } ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req, value); return ret < 0 ? ret : n; } static DEVICE_ATTR_RW(pm_qos_resume_latency_us); static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev, struct device_attribute *attr, char *buf) { s32 value = dev_pm_qos_get_user_latency_tolerance(dev); if (value < 0) return sprintf(buf, "auto\n"); if (value == PM_QOS_LATENCY_ANY) return sprintf(buf, "any\n"); return sprintf(buf, "%d\n", value); } static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { s32 value; int ret; if (kstrtos32(buf, 0, &value) == 0) { /* Users can't write negative values directly */ if (value < 0) return -EINVAL; } else { if (sysfs_streq(buf, "auto")) value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; else if (sysfs_streq(buf, "any")) value = PM_QOS_LATENCY_ANY; else return -EINVAL; } ret = dev_pm_qos_update_user_latency_tolerance(dev, value); return ret < 0 ? ret : n; } static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us); static ssize_t pm_qos_no_power_off_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev) & PM_QOS_FLAG_NO_POWER_OFF)); } static ssize_t pm_qos_no_power_off_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { int ret; if (kstrtoint(buf, 0, &ret)) return -EINVAL; if (ret != 0 && ret != 1) return -EINVAL; ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret); return ret < 0 ? ret : n; } static DEVICE_ATTR_RW(pm_qos_no_power_off); #ifdef CONFIG_PM_SLEEP static const char _enabled[] = "enabled"; static const char _disabled[] = "disabled"; static ssize_t wakeup_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 wakeup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) { if (!device_can_wakeup(dev)) return -EINVAL; if (sysfs_streq(buf, _enabled)) device_set_wakeup_enable(dev, 1); else if (sysfs_streq(buf, _disabled)) device_set_wakeup_enable(dev, 0); else return -EINVAL; return n; } static DEVICE_ATTR_RW(wakeup); 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->wakeup_count; enabled = true; } spin_unlock_irq(&dev->power.lock); return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n"); } static DEVICE_ATTR_RO(wakeup_count); 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_RO(wakeup_active_count); static ssize_t wakeup_abort_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->wakeup_count; enabled = true; } spin_unlock_irq(&dev->power.lock); return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n"); } static DEVICE_ATTR_RO(wakeup_abort_count); static ssize_t wakeup_expire_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->expire_count; enabled = true; } spin_unlock_irq(&dev->power.lock); return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n"); } static DEVICE_ATTR_RO(wakeup_expire_count); 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_RO(wakeup_active); static ssize_t wakeup_total_time_ms_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_RO(wakeup_total_time_ms); static ssize_t wakeup_max_time_ms_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_RO(wakeup_max_time_ms); static ssize_t wakeup_last_time_ms_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_RO(wakeup_last_time_ms); #ifdef CONFIG_PM_AUTOSLEEP static ssize_t wakeup_prevent_sleep_time_ms_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->prevent_sleep_time); enabled = true; } spin_unlock_irq(&dev->power.lock); return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n"); } static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms); #endif /* CONFIG_PM_AUTOSLEEP */ #endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_PM_ADVANCED_DEBUG static ssize_t runtime_usage_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count)); } static DEVICE_ATTR_RO(runtime_usage); static ssize_t runtime_active_kids_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 DEVICE_ATTR_RO(runtime_active_kids); static ssize_t runtime_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"); if (dev->power.disable_depth) return sprintf(buf, "disabled\n"); if (dev->power.runtime_auto == false) return sprintf(buf, "forbidden\n"); return sprintf(buf, "enabled\n"); } static DEVICE_ATTR_RO(runtime_enabled); #ifdef CONFIG_PM_SLEEP 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) { if (sysfs_streq(buf, _enabled)) device_enable_async_suspend(dev); else if (sysfs_streq(buf, _disabled)) device_disable_async_suspend(dev); else return -EINVAL; return n; } static DEVICE_ATTR_RW(async); #endif /* CONFIG_PM_SLEEP */ #endif /* CONFIG_PM_ADVANCED_DEBUG */ static struct attribute *power_attrs[] = { #ifdef CONFIG_PM_ADVANCED_DEBUG #ifdef CONFIG_PM_SLEEP &dev_attr_async.attr, #endif &dev_attr_runtime_status.attr, &dev_attr_runtime_usage.attr, &dev_attr_runtime_active_kids.attr, &dev_attr_runtime_enabled.attr, #endif /* CONFIG_PM_ADVANCED_DEBUG */ NULL, }; static const struct attribute_group pm_attr_group = { .name = power_group_name, .attrs = power_attrs, }; static struct attribute *wakeup_attrs[] = { #ifdef CONFIG_PM_SLEEP &dev_attr_wakeup.attr, &dev_attr_wakeup_count.attr, &dev_attr_wakeup_active_count.attr, &dev_attr_wakeup_abort_count.attr, &dev_attr_wakeup_expire_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, #ifdef CONFIG_PM_AUTOSLEEP &dev_attr_wakeup_prevent_sleep_time_ms.attr, #endif #endif NULL, }; static const struct attribute_group pm_wakeup_attr_group = { .name = power_group_name, .attrs = wakeup_attrs, }; 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 const struct attribute_group pm_runtime_attr_group = { .name = power_group_name, .attrs = runtime_attrs, }; static struct attribute *pm_qos_resume_latency_attrs[] = { &dev_attr_pm_qos_resume_latency_us.attr, NULL, }; static const struct attribute_group pm_qos_resume_latency_attr_group = { .name = power_group_name, .attrs = pm_qos_resume_latency_attrs, }; static struct attribute *pm_qos_latency_tolerance_attrs[] = { &dev_attr_pm_qos_latency_tolerance_us.attr, NULL, }; static const struct attribute_group pm_qos_latency_tolerance_attr_group = { .name = power_group_name, .attrs = pm_qos_latency_tolerance_attrs, }; static struct attribute *pm_qos_flags_attrs[] = { &dev_attr_pm_qos_no_power_off.attr, NULL, }; static const struct attribute_group pm_qos_flags_attr_group = { .name = power_group_name, .attrs = pm_qos_flags_attrs, }; int dpm_sysfs_add(struct device *dev) { int rc; rc = sysfs_create_group(&dev->kobj, &pm_attr_group); if (rc) return rc; if (pm_runtime_callbacks_present(dev)) { rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group); if (rc) goto err_out; } if (device_can_wakeup(dev)) { rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group); if (rc) goto err_runtime; } if (dev->power.set_latency_tolerance) { rc = sysfs_merge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); if (rc) goto err_wakeup; } return 0; err_wakeup: sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group); err_runtime: sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group); err_out: sysfs_remove_group(&dev->kobj, &pm_attr_group); return rc; } int wakeup_sysfs_add(struct device *dev) { return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group); } void wakeup_sysfs_remove(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group); } int pm_qos_sysfs_add_resume_latency(struct device *dev) { return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group); } void pm_qos_sysfs_remove_resume_latency(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group); } int pm_qos_sysfs_add_flags(struct device *dev) { return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group); } void pm_qos_sysfs_remove_flags(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group); } int pm_qos_sysfs_add_latency_tolerance(struct device *dev) { return sysfs_merge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); } void pm_qos_sysfs_remove_latency_tolerance(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); } void rpm_sysfs_remove(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group); } void dpm_sysfs_remove(struct device *dev) { sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); dev_pm_qos_constraints_destroy(dev); rpm_sysfs_remove(dev); sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group); sysfs_remove_group(&dev->kobj, &pm_attr_group); }