diff options
Diffstat (limited to 'drivers/base/power')
-rw-r--r-- | drivers/base/power/Makefile | 6 | ||||
-rw-r--r-- | drivers/base/power/main.c | 784 | ||||
-rw-r--r-- | drivers/base/power/power.h | 49 | ||||
-rw-r--r-- | drivers/base/power/sysfs.c | 98 | ||||
-rw-r--r-- | drivers/base/power/trace.c | 231 |
5 files changed, 1168 insertions, 0 deletions
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile new file mode 100644 index 0000000..911208b --- /dev/null +++ b/drivers/base/power/Makefile @@ -0,0 +1,6 @@ +obj-$(CONFIG_PM) += sysfs.o +obj-$(CONFIG_PM_SLEEP) += main.o +obj-$(CONFIG_PM_TRACE_RTC) += trace.o + +ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG +ccflags-$(CONFIG_PM_VERBOSE) += -DDEBUG diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c new file mode 100644 index 0000000..692c20b --- /dev/null +++ b/drivers/base/power/main.c @@ -0,0 +1,784 @@ +/* + * drivers/base/power/main.c - Where the driver meets power management. + * + * Copyright (c) 2003 Patrick Mochel + * Copyright (c) 2003 Open Source Development Lab + * + * This file is released under the GPLv2 + * + * + * The driver model core calls device_pm_add() when a device is registered. + * This will intialize the embedded device_pm_info object in the device + * and add it to the list of power-controlled devices. sysfs entries for + * controlling device power management will also be added. + * + * A separate list is used for keeping track of power info, because the power + * domain dependencies may differ from the ancestral dependencies that the + * subsystem list maintains. + */ + +#include <linux/device.h> +#include <linux/kallsyms.h> +#include <linux/mutex.h> +#include <linux/pm.h> +#include <linux/resume-trace.h> +#include <linux/rwsem.h> + +#include "../base.h" +#include "power.h" + +/* + * The entries in the dpm_list list are in a depth first order, simply + * because children are guaranteed to be discovered after parents, and + * are inserted at the back of the list on discovery. + * + * Since device_pm_add() may be called with a device semaphore held, + * we must never try to acquire a device semaphore while holding + * dpm_list_mutex. + */ + +LIST_HEAD(dpm_list); + +static DEFINE_MUTEX(dpm_list_mtx); + +/* + * Set once the preparation of devices for a PM transition has started, reset + * before starting to resume devices. Protected by dpm_list_mtx. + */ +static bool transition_started; + +/** + * device_pm_lock - lock the list of active devices used by the PM core + */ +void device_pm_lock(void) +{ + mutex_lock(&dpm_list_mtx); +} + +/** + * device_pm_unlock - unlock the list of active devices used by the PM core + */ +void device_pm_unlock(void) +{ + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_pm_add - add a device to the list of active devices + * @dev: Device to be added to the list + */ +void device_pm_add(struct device *dev) +{ + pr_debug("PM: Adding info for %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", + kobject_name(&dev->kobj)); + mutex_lock(&dpm_list_mtx); + if (dev->parent) { + if (dev->parent->power.status >= DPM_SUSPENDING) + dev_warn(dev, "parent %s should not be sleeping\n", + dev->parent->bus_id); + } else if (transition_started) { + /* + * We refuse to register parentless devices while a PM + * transition is in progress in order to avoid leaving them + * unhandled down the road + */ + dev_WARN(dev, "Parentless device registered during a PM transaction\n"); + } + + list_add_tail(&dev->power.entry, &dpm_list); + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_pm_remove - remove a device from the list of active devices + * @dev: Device to be removed from the list + * + * This function also removes the device's PM-related sysfs attributes. + */ +void device_pm_remove(struct device *dev) +{ + pr_debug("PM: Removing info for %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", + kobject_name(&dev->kobj)); + mutex_lock(&dpm_list_mtx); + list_del_init(&dev->power.entry); + mutex_unlock(&dpm_list_mtx); +} + +/** + * pm_op - execute the PM operation appropiate for given PM event + * @dev: Device. + * @ops: PM operations to choose from. + * @state: PM transition of the system being carried out. + */ +static int pm_op(struct device *dev, struct pm_ops *ops, pm_message_t state) +{ + int error = 0; + + switch (state.event) { +#ifdef CONFIG_SUSPEND + case PM_EVENT_SUSPEND: + if (ops->suspend) { + error = ops->suspend(dev); + suspend_report_result(ops->suspend, error); + } + break; + case PM_EVENT_RESUME: + if (ops->resume) { + error = ops->resume(dev); + suspend_report_result(ops->resume, error); + } + break; +#endif /* CONFIG_SUSPEND */ +#ifdef CONFIG_HIBERNATION + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + if (ops->freeze) { + error = ops->freeze(dev); + suspend_report_result(ops->freeze, error); + } + break; + case PM_EVENT_HIBERNATE: + if (ops->poweroff) { + error = ops->poweroff(dev); + suspend_report_result(ops->poweroff, error); + } + break; + case PM_EVENT_THAW: + case PM_EVENT_RECOVER: + if (ops->thaw) { + error = ops->thaw(dev); + suspend_report_result(ops->thaw, error); + } + break; + case PM_EVENT_RESTORE: + if (ops->restore) { + error = ops->restore(dev); + suspend_report_result(ops->restore, error); + } + break; +#endif /* CONFIG_HIBERNATION */ + default: + error = -EINVAL; + } + return error; +} + +/** + * pm_noirq_op - execute the PM operation appropiate for given PM event + * @dev: Device. + * @ops: PM operations to choose from. + * @state: PM transition of the system being carried out. + * + * The operation is executed with interrupts disabled by the only remaining + * functional CPU in the system. + */ +static int pm_noirq_op(struct device *dev, struct pm_ext_ops *ops, + pm_message_t state) +{ + int error = 0; + + switch (state.event) { +#ifdef CONFIG_SUSPEND + case PM_EVENT_SUSPEND: + if (ops->suspend_noirq) { + error = ops->suspend_noirq(dev); + suspend_report_result(ops->suspend_noirq, error); + } + break; + case PM_EVENT_RESUME: + if (ops->resume_noirq) { + error = ops->resume_noirq(dev); + suspend_report_result(ops->resume_noirq, error); + } + break; +#endif /* CONFIG_SUSPEND */ +#ifdef CONFIG_HIBERNATION + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + if (ops->freeze_noirq) { + error = ops->freeze_noirq(dev); + suspend_report_result(ops->freeze_noirq, error); + } + break; + case PM_EVENT_HIBERNATE: + if (ops->poweroff_noirq) { + error = ops->poweroff_noirq(dev); + suspend_report_result(ops->poweroff_noirq, error); + } + break; + case PM_EVENT_THAW: + case PM_EVENT_RECOVER: + if (ops->thaw_noirq) { + error = ops->thaw_noirq(dev); + suspend_report_result(ops->thaw_noirq, error); + } + break; + case PM_EVENT_RESTORE: + if (ops->restore_noirq) { + error = ops->restore_noirq(dev); + suspend_report_result(ops->restore_noirq, error); + } + break; +#endif /* CONFIG_HIBERNATION */ + default: + error = -EINVAL; + } + return error; +} + +static char *pm_verb(int event) +{ + switch (event) { + case PM_EVENT_SUSPEND: + return "suspend"; + case PM_EVENT_RESUME: + return "resume"; + case PM_EVENT_FREEZE: + return "freeze"; + case PM_EVENT_QUIESCE: + return "quiesce"; + case PM_EVENT_HIBERNATE: + return "hibernate"; + case PM_EVENT_THAW: + return "thaw"; + case PM_EVENT_RESTORE: + return "restore"; + case PM_EVENT_RECOVER: + return "recover"; + default: + return "(unknown PM event)"; + } +} + +static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info) +{ + dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event), + ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ? + ", may wakeup" : ""); +} + +static void pm_dev_err(struct device *dev, pm_message_t state, char *info, + int error) +{ + printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n", + kobject_name(&dev->kobj), pm_verb(state.event), info, error); +} + +/*------------------------- Resume routines -------------------------*/ + +/** + * resume_device_noirq - Power on one device (early resume). + * @dev: Device. + * @state: PM transition of the system being carried out. + * + * Must be called with interrupts disabled. + */ +static int resume_device_noirq(struct device *dev, pm_message_t state) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (!dev->bus) + goto End; + + if (dev->bus->pm) { + pm_dev_dbg(dev, state, "EARLY "); + error = pm_noirq_op(dev, dev->bus->pm, state); + } else if (dev->bus->resume_early) { + pm_dev_dbg(dev, state, "legacy EARLY "); + error = dev->bus->resume_early(dev); + } + End: + TRACE_RESUME(error); + return error; +} + +/** + * dpm_power_up - Power on all regular (non-sysdev) devices. + * @state: PM transition of the system being carried out. + * + * Execute the appropriate "noirq resume" callback for all devices marked + * as DPM_OFF_IRQ. + * + * Must be called with interrupts disabled and only one CPU running. + */ +static void dpm_power_up(pm_message_t state) +{ + struct device *dev; + + list_for_each_entry(dev, &dpm_list, power.entry) + if (dev->power.status > DPM_OFF) { + int error; + + dev->power.status = DPM_OFF; + error = resume_device_noirq(dev, state); + if (error) + pm_dev_err(dev, state, " early", error); + } +} + +/** + * device_power_up - Turn on all devices that need special attention. + * @state: PM transition of the system being carried out. + * + * Power on system devices, then devices that required we shut them down + * with interrupts disabled. + * + * Must be called with interrupts disabled. + */ +void device_power_up(pm_message_t state) +{ + sysdev_resume(); + dpm_power_up(state); +} +EXPORT_SYMBOL_GPL(device_power_up); + +/** + * resume_device - Restore state for one device. + * @dev: Device. + * @state: PM transition of the system being carried out. + */ +static int resume_device(struct device *dev, pm_message_t state) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + down(&dev->sem); + + if (dev->bus) { + if (dev->bus->pm) { + pm_dev_dbg(dev, state, ""); + error = pm_op(dev, &dev->bus->pm->base, state); + } else if (dev->bus->resume) { + pm_dev_dbg(dev, state, "legacy "); + error = dev->bus->resume(dev); + } + if (error) + goto End; + } + + if (dev->type) { + if (dev->type->pm) { + pm_dev_dbg(dev, state, "type "); + error = pm_op(dev, dev->type->pm, state); + } else if (dev->type->resume) { + pm_dev_dbg(dev, state, "legacy type "); + error = dev->type->resume(dev); + } + if (error) + goto End; + } + + if (dev->class) { + if (dev->class->pm) { + pm_dev_dbg(dev, state, "class "); + error = pm_op(dev, dev->class->pm, state); + } else if (dev->class->resume) { + pm_dev_dbg(dev, state, "legacy class "); + error = dev->class->resume(dev); + } + } + End: + up(&dev->sem); + + TRACE_RESUME(error); + return error; +} + +/** + * dpm_resume - Resume every device. + * @state: PM transition of the system being carried out. + * + * Execute the appropriate "resume" callback for all devices the status of + * which indicates that they are inactive. + */ +static void dpm_resume(pm_message_t state) +{ + struct list_head list; + + INIT_LIST_HEAD(&list); + mutex_lock(&dpm_list_mtx); + transition_started = false; + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.next); + + get_device(dev); + if (dev->power.status >= DPM_OFF) { + int error; + + dev->power.status = DPM_RESUMING; + mutex_unlock(&dpm_list_mtx); + + error = resume_device(dev, state); + + mutex_lock(&dpm_list_mtx); + if (error) + pm_dev_err(dev, state, "", error); + } else if (dev->power.status == DPM_SUSPENDING) { + /* Allow new children of the device to be registered */ + dev->power.status = DPM_RESUMING; + } + if (!list_empty(&dev->power.entry)) + list_move_tail(&dev->power.entry, &list); + put_device(dev); + } + list_splice(&list, &dpm_list); + mutex_unlock(&dpm_list_mtx); +} + +/** + * complete_device - Complete a PM transition for given device + * @dev: Device. + * @state: PM transition of the system being carried out. + */ +static void complete_device(struct device *dev, pm_message_t state) +{ + down(&dev->sem); + + if (dev->class && dev->class->pm && dev->class->pm->complete) { + pm_dev_dbg(dev, state, "completing class "); + dev->class->pm->complete(dev); + } + + if (dev->type && dev->type->pm && dev->type->pm->complete) { + pm_dev_dbg(dev, state, "completing type "); + dev->type->pm->complete(dev); + } + + if (dev->bus && dev->bus->pm && dev->bus->pm->base.complete) { + pm_dev_dbg(dev, state, "completing "); + dev->bus->pm->base.complete(dev); + } + + up(&dev->sem); +} + +/** + * dpm_complete - Complete a PM transition for all devices. + * @state: PM transition of the system being carried out. + * + * Execute the ->complete() callbacks for all devices that are not marked + * as DPM_ON. + */ +static void dpm_complete(pm_message_t state) +{ + struct list_head list; + + INIT_LIST_HEAD(&list); + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.prev); + + get_device(dev); + if (dev->power.status > DPM_ON) { + dev->power.status = DPM_ON; + mutex_unlock(&dpm_list_mtx); + + complete_device(dev, state); + + mutex_lock(&dpm_list_mtx); + } + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &list); + put_device(dev); + } + list_splice(&list, &dpm_list); + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_resume - Restore state of each device in system. + * @state: PM transition of the system being carried out. + * + * Resume all the devices, unlock them all, and allow new + * devices to be registered once again. + */ +void device_resume(pm_message_t state) +{ + might_sleep(); + dpm_resume(state); + dpm_complete(state); +} +EXPORT_SYMBOL_GPL(device_resume); + + +/*------------------------- Suspend routines -------------------------*/ + +/** + * resume_event - return a PM message representing the resume event + * corresponding to given sleep state. + * @sleep_state: PM message representing a sleep state. + */ +static pm_message_t resume_event(pm_message_t sleep_state) +{ + switch (sleep_state.event) { + case PM_EVENT_SUSPEND: + return PMSG_RESUME; + case PM_EVENT_FREEZE: + case PM_EVENT_QUIESCE: + return PMSG_RECOVER; + case PM_EVENT_HIBERNATE: + return PMSG_RESTORE; + } + return PMSG_ON; +} + +/** + * suspend_device_noirq - Shut down one device (late suspend). + * @dev: Device. + * @state: PM transition of the system being carried out. + * + * This is called with interrupts off and only a single CPU running. + */ +static int suspend_device_noirq(struct device *dev, pm_message_t state) +{ + int error = 0; + + if (!dev->bus) + return 0; + + if (dev->bus->pm) { + pm_dev_dbg(dev, state, "LATE "); + error = pm_noirq_op(dev, dev->bus->pm, state); + } else if (dev->bus->suspend_late) { + pm_dev_dbg(dev, state, "legacy LATE "); + error = dev->bus->suspend_late(dev, state); + suspend_report_result(dev->bus->suspend_late, error); + } + return error; +} + +/** + * device_power_down - Shut down special devices. + * @state: PM transition of the system being carried out. + * + * Power down devices that require interrupts to be disabled. + * Then power down system devices. + * + * Must be called with interrupts disabled and only one CPU running. + */ +int device_power_down(pm_message_t state) +{ + struct device *dev; + int error = 0; + + list_for_each_entry_reverse(dev, &dpm_list, power.entry) { + error = suspend_device_noirq(dev, state); + if (error) { + pm_dev_err(dev, state, " late", error); + break; + } + dev->power.status = DPM_OFF_IRQ; + } + if (!error) + error = sysdev_suspend(state); + if (error) + dpm_power_up(resume_event(state)); + return error; +} +EXPORT_SYMBOL_GPL(device_power_down); + +/** + * suspend_device - Save state of one device. + * @dev: Device. + * @state: PM transition of the system being carried out. + */ +static int suspend_device(struct device *dev, pm_message_t state) +{ + int error = 0; + + down(&dev->sem); + + if (dev->class) { + if (dev->class->pm) { + pm_dev_dbg(dev, state, "class "); + error = pm_op(dev, dev->class->pm, state); + } else if (dev->class->suspend) { + pm_dev_dbg(dev, state, "legacy class "); + error = dev->class->suspend(dev, state); + suspend_report_result(dev->class->suspend, error); + } + if (error) + goto End; + } + + if (dev->type) { + if (dev->type->pm) { + pm_dev_dbg(dev, state, "type "); + error = pm_op(dev, dev->type->pm, state); + } else if (dev->type->suspend) { + pm_dev_dbg(dev, state, "legacy type "); + error = dev->type->suspend(dev, state); + suspend_report_result(dev->type->suspend, error); + } + if (error) + goto End; + } + + if (dev->bus) { + if (dev->bus->pm) { + pm_dev_dbg(dev, state, ""); + error = pm_op(dev, &dev->bus->pm->base, state); + } else if (dev->bus->suspend) { + pm_dev_dbg(dev, state, "legacy "); + error = dev->bus->suspend(dev, state); + suspend_report_result(dev->bus->suspend, error); + } + } + End: + up(&dev->sem); + + return error; +} + +/** + * dpm_suspend - Suspend every device. + * @state: PM transition of the system being carried out. + * + * Execute the appropriate "suspend" callbacks for all devices. + */ +static int dpm_suspend(pm_message_t state) +{ + struct list_head list; + int error = 0; + + INIT_LIST_HEAD(&list); + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = suspend_device(dev, state); + + mutex_lock(&dpm_list_mtx); + if (error) { + pm_dev_err(dev, state, "", error); + put_device(dev); + break; + } + dev->power.status = DPM_OFF; + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &list); + put_device(dev); + } + list_splice(&list, dpm_list.prev); + mutex_unlock(&dpm_list_mtx); + return error; +} + +/** + * prepare_device - Execute the ->prepare() callback(s) for given device. + * @dev: Device. + * @state: PM transition of the system being carried out. + */ +static int prepare_device(struct device *dev, pm_message_t state) +{ + int error = 0; + + down(&dev->sem); + + if (dev->bus && dev->bus->pm && dev->bus->pm->base.prepare) { + pm_dev_dbg(dev, state, "preparing "); + error = dev->bus->pm->base.prepare(dev); + suspend_report_result(dev->bus->pm->base.prepare, error); + if (error) + goto End; + } + + if (dev->type && dev->type->pm && dev->type->pm->prepare) { + pm_dev_dbg(dev, state, "preparing type "); + error = dev->type->pm->prepare(dev); + suspend_report_result(dev->type->pm->prepare, error); + if (error) + goto End; + } + + if (dev->class && dev->class->pm && dev->class->pm->prepare) { + pm_dev_dbg(dev, state, "preparing class "); + error = dev->class->pm->prepare(dev); + suspend_report_result(dev->class->pm->prepare, error); + } + End: + up(&dev->sem); + + return error; +} + +/** + * dpm_prepare - Prepare all devices for a PM transition. + * @state: PM transition of the system being carried out. + * + * Execute the ->prepare() callback for all devices. + */ +static int dpm_prepare(pm_message_t state) +{ + struct list_head list; + int error = 0; + + INIT_LIST_HEAD(&list); + mutex_lock(&dpm_list_mtx); + transition_started = true; + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.next); + + get_device(dev); + dev->power.status = DPM_PREPARING; + mutex_unlock(&dpm_list_mtx); + + error = prepare_device(dev, state); + + mutex_lock(&dpm_list_mtx); + if (error) { + dev->power.status = DPM_ON; + if (error == -EAGAIN) { + put_device(dev); + continue; + } + printk(KERN_ERR "PM: Failed to prepare device %s " + "for power transition: error %d\n", + kobject_name(&dev->kobj), error); + put_device(dev); + break; + } + dev->power.status = DPM_SUSPENDING; + if (!list_empty(&dev->power.entry)) + list_move_tail(&dev->power.entry, &list); + put_device(dev); + } + list_splice(&list, &dpm_list); + mutex_unlock(&dpm_list_mtx); + return error; +} + +/** + * device_suspend - Save state and stop all devices in system. + * @state: PM transition of the system being carried out. + * + * Prepare and suspend all devices. + */ +int device_suspend(pm_message_t state) +{ + int error; + + might_sleep(); + error = dpm_prepare(state); + if (!error) + error = dpm_suspend(state); + return error; +} +EXPORT_SYMBOL_GPL(device_suspend); + +void __suspend_report_result(const char *function, void *fn, int ret) +{ + if (ret) + printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret); +} +EXPORT_SYMBOL_GPL(__suspend_report_result); diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h new file mode 100644 index 0000000..41f51fa --- /dev/null +++ b/drivers/base/power/power.h @@ -0,0 +1,49 @@ +static inline void device_pm_init(struct device *dev) +{ + dev->power.status = DPM_ON; +} + +#ifdef CONFIG_PM_SLEEP + +/* + * main.c + */ + +extern struct list_head dpm_list; /* The active device list */ + +static inline struct device *to_device(struct list_head *entry) +{ + return container_of(entry, struct device, power.entry); +} + +extern void device_pm_add(struct device *); +extern void device_pm_remove(struct device *); + +#else /* CONFIG_PM_SLEEP */ + +static inline void device_pm_add(struct device *dev) {} +static inline void device_pm_remove(struct device *dev) {} + +#endif + +#ifdef CONFIG_PM + +/* + * sysfs.c + */ + +extern int dpm_sysfs_add(struct device *); +extern void dpm_sysfs_remove(struct device *); + +#else /* CONFIG_PM */ + +static inline int dpm_sysfs_add(struct device *dev) +{ + return 0; +} + +static inline void dpm_sysfs_remove(struct device *dev) +{ +} + +#endif diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c new file mode 100644 index 0000000..596aeec --- /dev/null +++ b/drivers/base/power/sysfs.c @@ -0,0 +1,98 @@ +/* + * drivers/base/power/sysfs.c - sysfs entries for device PM + */ + +#include <linux/device.h> +#include <linux/string.h> +#include "power.h" + +/* + * 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. + */ + +static const char enabled[] = "enabled"; +static const char disabled[] = "disabled"; + +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); + + +static struct attribute * power_attrs[] = { + &dev_attr_wakeup.attr, + NULL, +}; +static struct attribute_group pm_attr_group = { + .name = "power", + .attrs = power_attrs, +}; + +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); +} diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c new file mode 100644 index 0000000..2aa6e8f --- /dev/null +++ b/drivers/base/power/trace.c @@ -0,0 +1,231 @@ +/* + * drivers/base/power/trace.c + * + * Copyright (C) 2006 Linus Torvalds + * + * Trace facility for suspend/resume problems, when none of the + * devices may be working. + */ + +#include <linux/resume-trace.h> +#include <linux/rtc.h> + +#include <asm/rtc.h> + +#include "power.h" + +/* + * Horrid, horrid, horrid. + * + * It turns out that the _only_ piece of hardware that actually + * keeps its value across a hard boot (and, more importantly, the + * POST init sequence) is literally the realtime clock. + * + * Never mind that an RTC chip has 114 bytes (and often a whole + * other bank of an additional 128 bytes) of nice SRAM that is + * _designed_ to keep data - the POST will clear it. So we literally + * can just use the few bytes of actual time data, which means that + * we're really limited. + * + * It means, for example, that we can't use the seconds at all + * (since the time between the hang and the boot might be more + * than a minute), and we'd better not depend on the low bits of + * the minutes either. + * + * There are the wday fields etc, but I wouldn't guarantee those + * are dependable either. And if the date isn't valid, either the + * hw or POST will do strange things. + * + * So we're left with: + * - year: 0-99 + * - month: 0-11 + * - day-of-month: 1-28 + * - hour: 0-23 + * - min: (0-30)*2 + * + * Giving us a total range of 0-16128000 (0xf61800), ie less + * than 24 bits of actual data we can save across reboots. + * + * And if your box can't boot in less than three minutes, + * you're screwed. + * + * Now, almost 24 bits of data is pitifully small, so we need + * to be pretty dense if we want to use it for anything nice. + * What we do is that instead of saving off nice readable info, + * we save off _hashes_ of information that we can hopefully + * regenerate after the reboot. + * + * In particular, this means that we might be unlucky, and hit + * a case where we have a hash collision, and we end up not + * being able to tell for certain exactly which case happened. + * But that's hopefully unlikely. + * + * What we do is to take the bits we can fit, and split them + * into three parts (16*997*1009 = 16095568), and use the values + * for: + * - 0-15: user-settable + * - 0-996: file + line number + * - 0-1008: device + */ +#define USERHASH (16) +#define FILEHASH (997) +#define DEVHASH (1009) + +#define DEVSEED (7919) + +static unsigned int dev_hash_value; + +static int set_magic_time(unsigned int user, unsigned int file, unsigned int device) +{ + unsigned int n = user + USERHASH*(file + FILEHASH*device); + + // June 7th, 2006 + static struct rtc_time time = { + .tm_sec = 0, + .tm_min = 0, + .tm_hour = 0, + .tm_mday = 7, + .tm_mon = 5, // June - counting from zero + .tm_year = 106, + .tm_wday = 3, + .tm_yday = 160, + .tm_isdst = 1 + }; + + time.tm_year = (n % 100); + n /= 100; + time.tm_mon = (n % 12); + n /= 12; + time.tm_mday = (n % 28) + 1; + n /= 28; + time.tm_hour = (n % 24); + n /= 24; + time.tm_min = (n % 20) * 3; + n /= 20; + set_rtc_time(&time); + return n ? -1 : 0; +} + +static unsigned int read_magic_time(void) +{ + struct rtc_time time; + unsigned int val; + + get_rtc_time(&time); + printk("Time: %2d:%02d:%02d Date: %02d/%02d/%02d\n", + time.tm_hour, time.tm_min, time.tm_sec, + time.tm_mon + 1, time.tm_mday, time.tm_year % 100); + val = time.tm_year; /* 100 years */ + if (val > 100) + val -= 100; + val += time.tm_mon * 100; /* 12 months */ + val += (time.tm_mday-1) * 100 * 12; /* 28 month-days */ + val += time.tm_hour * 100 * 12 * 28; /* 24 hours */ + val += (time.tm_min / 3) * 100 * 12 * 28 * 24; /* 20 3-minute intervals */ + return val; +} + +/* + * This is just the sdbm hash function with a user-supplied + * seed and final size parameter. + */ +static unsigned int hash_string(unsigned int seed, const char *data, unsigned int mod) +{ + unsigned char c; + while ((c = *data++) != 0) { + seed = (seed << 16) + (seed << 6) - seed + c; + } + return seed % mod; +} + +void set_trace_device(struct device *dev) +{ + dev_hash_value = hash_string(DEVSEED, dev->bus_id, DEVHASH); +} +EXPORT_SYMBOL(set_trace_device); + +/* + * We could just take the "tracedata" index into the .tracedata + * section instead. Generating a hash of the data gives us a + * chance to work across kernel versions, and perhaps more + * importantly it also gives us valid/invalid check (ie we will + * likely not give totally bogus reports - if the hash matches, + * it's not any guarantee, but it's a high _likelihood_ that + * the match is valid). + */ +void generate_resume_trace(const void *tracedata, unsigned int user) +{ + unsigned short lineno = *(unsigned short *)tracedata; + const char *file = *(const char **)(tracedata + 2); + unsigned int user_hash_value, file_hash_value; + + user_hash_value = user % USERHASH; + file_hash_value = hash_string(lineno, file, FILEHASH); + set_magic_time(user_hash_value, file_hash_value, dev_hash_value); +} +EXPORT_SYMBOL(generate_resume_trace); + +extern char __tracedata_start, __tracedata_end; +static int show_file_hash(unsigned int value) +{ + int match; + char *tracedata; + + match = 0; + for (tracedata = &__tracedata_start ; tracedata < &__tracedata_end ; + tracedata += 2 + sizeof(unsigned long)) { + unsigned short lineno = *(unsigned short *)tracedata; + const char *file = *(const char **)(tracedata + 2); + unsigned int hash = hash_string(lineno, file, FILEHASH); + if (hash != value) + continue; + printk(" hash matches %s:%u\n", file, lineno); + match++; + } + return match; +} + +static int show_dev_hash(unsigned int value) +{ + int match = 0; + struct list_head *entry = dpm_list.prev; + + while (entry != &dpm_list) { + struct device * dev = to_device(entry); + unsigned int hash = hash_string(DEVSEED, dev->bus_id, DEVHASH); + if (hash == value) { + dev_info(dev, "hash matches\n"); + match++; + } + entry = entry->prev; + } + return match; +} + +static unsigned int hash_value_early_read; + +static int early_resume_init(void) +{ + hash_value_early_read = read_magic_time(); + return 0; +} + +static int late_resume_init(void) +{ + unsigned int val = hash_value_early_read; + unsigned int user, file, dev; + + user = val % USERHASH; + val = val / USERHASH; + file = val % FILEHASH; + val = val / FILEHASH; + dev = val /* % DEVHASH */; + + printk(" Magic number: %d:%d:%d\n", user, file, dev); + show_file_hash(file); + show_dev_hash(dev); + return 0; +} + +core_initcall(early_resume_init); +late_initcall(late_resume_init); |