Creation of Cybook 2416 (actually Gen4) repository

drivers/base/power/Makefile

@@ -0,0 +1,10 @@
+obj-y			:= shutdown.o
+obj-$(CONFIG_PM)	+= main.o suspend.o resume.o runtime.o sysfs.o
+obj-$(CONFIG_PM_TRACE)	+= trace.o
+
+ifeq ($(CONFIG_DEBUG_DRIVER),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+ifeq ($(CONFIG_PM_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif

drivers/base/power/main.c

@@ -0,0 +1,80 @@
+/*
+ * 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 different set of lists than the global subsystem list are used to
+ * keep track of power info because we use different lists to hold
+ * devices based on what stage of the power management process they
+ * are in. The power domain dependencies may also differ from the
+ * ancestral dependencies that the subsystem list maintains.
+ */
+
+#include <linux/device.h>
+#include "power.h"
+
+LIST_HEAD(dpm_active);
+LIST_HEAD(dpm_off);
+LIST_HEAD(dpm_off_irq);
+
+DECLARE_MUTEX(dpm_sem);
+DECLARE_MUTEX(dpm_list_sem);
+
+/**
+ *	device_pm_set_parent - Specify power dependency.
+ *	@dev:		Device who needs power.
+ *	@parent:	Device that supplies power.
+ *
+ *	This function is used to manually describe a power-dependency
+ *	relationship. It may be used to specify a transversal relationship
+ *	(where the power supplier is not the physical (or electrical)
+ *	ancestor of a specific device.
+ *	The effect of this is that the supplier will not be powered down
+ *	before the power dependent.
+ */
+
+void device_pm_set_parent(struct device * dev, struct device * parent)
+{
+	put_device(dev->power.pm_parent);
+	dev->power.pm_parent = get_device(parent);
+}
+EXPORT_SYMBOL_GPL(device_pm_set_parent);
+
+int device_pm_add(struct device * dev)
+{
+	int error;
+
+	pr_debug("PM: Adding info for %s:%s\n",
+		 dev->bus ? dev->bus->name : "No Bus",
+		 kobject_name(&dev->kobj));
+	down(&dpm_list_sem);
+	list_add_tail(&dev->power.entry, &dpm_active);
+	device_pm_set_parent(dev, dev->parent);
+	if ((error = dpm_sysfs_add(dev)))
+		list_del(&dev->power.entry);
+	up(&dpm_list_sem);
+	return error;
+}
+
+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));
+	down(&dpm_list_sem);
+	dpm_sysfs_remove(dev);
+	put_device(dev->power.pm_parent);
+	list_del_init(&dev->power.entry);
+	up(&dpm_list_sem);
+}
+
+

drivers/base/power/power.h

@@ -0,0 +1,82 @@
+/*
+ * shutdown.c
+ */
+
+extern void device_shutdown(void);
+
+
+#ifdef CONFIG_PM
+
+/*
+ * main.c
+ */
+
+/*
+ * Used to synchronize global power management operations.
+ */
+extern struct semaphore dpm_sem;
+
+/*
+ * Used to serialize changes to the dpm_* lists.
+ */
+extern struct semaphore dpm_list_sem;
+
+/*
+ * The PM lists.
+ */
+extern struct list_head dpm_active;
+extern struct list_head dpm_off;
+extern struct list_head dpm_off_irq;
+
+
+static inline struct dev_pm_info * to_pm_info(struct list_head * entry)
+{
+	return container_of(entry, struct dev_pm_info, entry);
+}
+
+static inline struct device * to_device(struct list_head * entry)
+{
+	return container_of(to_pm_info(entry), struct device, power);
+}
+
+extern int device_pm_add(struct device *);
+extern void device_pm_remove(struct device *);
+
+/*
+ * sysfs.c
+ */
+
+extern int dpm_sysfs_add(struct device *);
+extern void dpm_sysfs_remove(struct device *);
+
+/*
+ * resume.c
+ */
+
+extern void dpm_resume(void);
+extern void dpm_power_up(void);
+extern int resume_device(struct device *);
+
+/*
+ * suspend.c
+ */
+extern int suspend_device(struct device *, pm_message_t);
+
+
+/*
+ * runtime.c
+ */
+
+#else /* CONFIG_PM */
+
+
+static inline int device_pm_add(struct device * dev)
+{
+	return 0;
+}
+static inline void device_pm_remove(struct device * dev)
+{
+
+}
+
+#endif

drivers/base/power/resume.c

@@ -0,0 +1,147 @@
+/*
+ * resume.c - Functions for waking devices up.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Labs
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/resume-trace.h>
+#include "../base.h"
+#include "power.h"
+
+
+/**
+ *	resume_device - Restore state for one device.
+ *	@dev:	Device.
+ *
+ */
+
+int resume_device(struct device * dev)
+{
+	int error = 0;
+
+	TRACE_DEVICE(dev);
+	TRACE_RESUME(0);
+	down(&dev->sem);
+	if (dev->power.pm_parent
+			&& dev->power.pm_parent->power.power_state.event) {
+		dev_err(dev, "PM: resume from %d, parent %s still %d\n",
+			dev->power.power_state.event,
+			dev->power.pm_parent->bus_id,
+			dev->power.pm_parent->power.power_state.event);
+	}
+	if (dev->bus && dev->bus->resume) {
+		dev_dbg(dev,"resuming\n");
+		error = dev->bus->resume(dev);
+	}
+	if (dev->class && dev->class->resume) {
+		dev_dbg(dev,"class resume\n");
+		error = dev->class->resume(dev);
+	}
+	up(&dev->sem);
+	TRACE_RESUME(error);
+	return error;
+}
+
+
+static int resume_device_early(struct device * dev)
+{
+	int error = 0;
+
+	TRACE_DEVICE(dev);
+	TRACE_RESUME(0);
+	if (dev->bus && dev->bus->resume_early) {
+		dev_dbg(dev,"EARLY resume\n");
+		error = dev->bus->resume_early(dev);
+	}
+	TRACE_RESUME(error);
+	return error;
+}
+
+/*
+ * Resume the devices that have either not gone through
+ * the late suspend, or that did go through it but also
+ * went through the early resume
+ */
+void dpm_resume(void)
+{
+	down(&dpm_list_sem);
+	while(!list_empty(&dpm_off)) {
+		struct list_head * entry = dpm_off.next;
+		struct device * dev = to_device(entry);
+
+		get_device(dev);
+		list_move_tail(entry, &dpm_active);
+
+		up(&dpm_list_sem);
+		if (!dev->power.prev_state.event)
+			resume_device(dev);
+		down(&dpm_list_sem);
+		put_device(dev);
+	}
+	up(&dpm_list_sem);
+}
+
+
+/**
+ *	device_resume - Restore state of each device in system.
+ *
+ *	Walk the dpm_off list, remove each entry, resume the device,
+ *	then add it to the dpm_active list.
+ */
+
+void device_resume(void)
+{
+	might_sleep();
+	down(&dpm_sem);
+	dpm_resume();
+	up(&dpm_sem);
+}
+
+EXPORT_SYMBOL_GPL(device_resume);
+
+
+/**
+ *	dpm_power_up - Power on some devices.
+ *
+ *	Walk the dpm_off_irq list and power each device up. This
+ *	is used for devices that required they be powered down with
+ *	interrupts disabled. As devices are powered on, they are moved
+ *	to the dpm_active list.
+ *
+ *	Interrupts must be disabled when calling this.
+ */
+
+void dpm_power_up(void)
+{
+	while(!list_empty(&dpm_off_irq)) {
+		struct list_head * entry = dpm_off_irq.next;
+		struct device * dev = to_device(entry);
+
+		list_move_tail(entry, &dpm_off);
+		resume_device_early(dev);
+	}
+}
+
+
+/**
+ *	device_power_up - Turn on all devices that need special attention.
+ *
+ *	Power on system devices then devices that required we shut them down
+ *	with interrupts disabled.
+ *	Called with interrupts disabled.
+ */
+
+void device_power_up(void)
+{
+	sysdev_resume();
+	dpm_power_up();
+}
+
+EXPORT_SYMBOL_GPL(device_power_up);
+
+

drivers/base/power/runtime.c

@@ -0,0 +1,85 @@
+/*
+ * drivers/base/power/runtime.c - Handling dynamic device power management.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ *
+ */
+
+#include <linux/device.h>
+#include "power.h"
+
+
+static void runtime_resume(struct device * dev)
+{
+	dev_dbg(dev, "resuming\n");
+	if (!dev->power.power_state.event)
+		return;
+	if (!resume_device(dev))
+		dev->power.power_state = PMSG_ON;
+}
+
+
+/**
+ *	dpm_runtime_resume - Power one device back on.
+ *	@dev:	Device.
+ *
+ *	Bring one device back to the on state by first powering it
+ *	on, then restoring state. We only operate on devices that aren't
+ *	already on.
+ *	FIXME: We need to handle devices that are in an unknown state.
+ */
+
+void dpm_runtime_resume(struct device * dev)
+{
+	down(&dpm_sem);
+	runtime_resume(dev);
+	up(&dpm_sem);
+}
+EXPORT_SYMBOL(dpm_runtime_resume);
+
+
+/**
+ *	dpm_runtime_suspend - Put one device in low-power state.
+ *	@dev:	Device.
+ *	@state:	State to enter.
+ */
+
+int dpm_runtime_suspend(struct device * dev, pm_message_t state)
+{
+	int error = 0;
+
+	down(&dpm_sem);
+	if (dev->power.power_state.event == state.event)
+		goto Done;
+
+	if (dev->power.power_state.event)
+		runtime_resume(dev);
+
+	if (!(error = suspend_device(dev, state)))
+		dev->power.power_state = state;
+ Done:
+	up(&dpm_sem);
+	return error;
+}
+EXPORT_SYMBOL(dpm_runtime_suspend);
+
+
+#if 0
+/**
+ *	dpm_set_power_state - Update power_state field.
+ *	@dev:	Device.
+ *	@state:	Power state device is in.
+ *
+ *	This is an update mechanism for drivers to notify the core
+ *	what power state a device is in. Device probing code may not
+ *	always be able to tell, but we need accurate information to
+ *	work reliably.
+ */
+void dpm_set_power_state(struct device * dev, pm_message_t state)
+{
+	down(&dpm_sem);
+	dev->power.power_state = state;
+	up(&dpm_sem);
+}
+#endif  /*  0  */

drivers/base/power/shutdown.c

@@ -0,0 +1,54 @@
+/*
+ * shutdown.c - power management functions for the device tree.
+ *
+ * Copyright (c) 2002-3 Patrick Mochel
+ *		 2002-3 Open Source Development Lab
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include <asm/semaphore.h>
+
+#include "../base.h"
+#include "power.h"
+
+#define to_dev(node) container_of(node, struct device, kobj.entry)
+
+extern struct subsystem devices_subsys;
+
+
+/**
+ * We handle system devices differently - we suspend and shut them
+ * down last and resume them first. That way, we don't do anything stupid like
+ * shutting down the interrupt controller before any devices..
+ *
+ * Note that there are not different stages for power management calls -
+ * they only get one called once when interrupts are disabled.
+ */
+
+
+/**
+ * device_shutdown - call ->shutdown() on each device to shutdown.
+ */
+void device_shutdown(void)
+{
+	struct device * dev, *devn;
+
+	down_write(&devices_subsys.rwsem);
+	list_for_each_entry_safe_reverse(dev, devn, &devices_subsys.kset.list,
+				kobj.entry) {
+		if (dev->bus && dev->bus->shutdown) {
+			dev_dbg(dev, "shutdown\n");
+			dev->bus->shutdown(dev);
+		} else if (dev->driver && dev->driver->shutdown) {
+			dev_dbg(dev, "shutdown\n");
+			dev->driver->shutdown(dev);
+		}
+	}
+	up_write(&devices_subsys.rwsem);
+
+	sysdev_shutdown();
+}
+

drivers/base/power/suspend.c

@@ -0,0 +1,237 @@
+/*
+ * suspend.c - Functions for putting devices to sleep.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Labs
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/kallsyms.h>
+#include <linux/pm.h>
+#include "../base.h"
+#include "power.h"
+
+#ifdef CONFIG_PM_CPU_MODE
+extern unsigned char pm_cpu_mode;
+#endif
+
+/*
+ * The entries in the dpm_active 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.
+ *
+ * All list on the suspend path are done in reverse order, so we operate
+ * on the leaves of the device tree (or forests, depending on how you want
+ * to look at it ;) first. As nodes are removed from the back of the list,
+ * they are inserted into the front of their destintation lists.
+ *
+ * Things are the reverse on the resume path - iterations are done in
+ * forward order, and nodes are inserted at the back of their destination
+ * lists. This way, the ancestors will be accessed before their descendents.
+ */
+
+static inline char *suspend_verb(u32 event)
+{
+	switch (event) {
+	case PM_EVENT_SUSPEND:	return "suspend";
+	case PM_EVENT_FREEZE:	return "freeze";
+	case PM_EVENT_PRETHAW:	return "prethaw";
+	default:		return "(unknown suspend event)";
+	}
+}
+
+
+/**
+ *	suspend_device - Save state of one device.
+ *	@dev:	Device.
+ *	@state:	Power state device is entering.
+ */
+
+int suspend_device(struct device * dev, pm_message_t state)
+{
+	int error = 0;
+
+	down(&dev->sem);
+	if (dev->power.power_state.event) {
+		dev_dbg(dev, "PM: suspend %d-->%d\n",
+			dev->power.power_state.event, state.event);
+	}
+	if (dev->power.pm_parent
+			&& dev->power.pm_parent->power.power_state.event) {
+		dev_err(dev,
+			"PM: suspend %d->%d, parent %s already %d\n",
+			dev->power.power_state.event, state.event,
+			dev->power.pm_parent->bus_id,
+			dev->power.pm_parent->power.power_state.event);
+	}
+
+	dev->power.prev_state = dev->power.power_state;
+
+	if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
+		dev_dbg(dev, "class %s%s\n",
+			suspend_verb(state.event),
+			((state.event == PM_EVENT_SUSPEND)
+					&& device_may_wakeup(dev))
+				? ", may wakeup"
+				: ""
+			);
+		error = dev->class->suspend(dev, state);
+		suspend_report_result(dev->class->suspend, error);
+	}
+
+	if (!error && dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
+		dev_dbg(dev, "%s%s\n",
+			suspend_verb(state.event),
+			((state.event == PM_EVENT_SUSPEND)
+					&& device_may_wakeup(dev))
+				? ", may wakeup"
+				: ""
+			);
+		error = dev->bus->suspend(dev, state);
+		suspend_report_result(dev->bus->suspend, error);
+	}
+	up(&dev->sem);
+	return error;
+}
+
+
+/*
+ * This is called with interrupts off, only a single CPU
+ * running. We can't do down() on a semaphore (and we don't
+ * need the protection)
+ */
+static int suspend_device_late(struct device *dev, pm_message_t state)
+{
+	int error = 0;
+
+	if (dev->bus && dev->bus->suspend_late && !dev->power.power_state.event) {
+		dev_dbg(dev, "LATE %s%s\n",
+			suspend_verb(state.event),
+			((state.event == PM_EVENT_SUSPEND)
+					&& device_may_wakeup(dev))
+				? ", may wakeup"
+				: ""
+			);
+		error = dev->bus->suspend_late(dev, state);
+		suspend_report_result(dev->bus->suspend_late, error);
+	}
+	return error;
+}
+
+/**
+ *	device_suspend - Save state and stop all devices in system.
+ *	@state:		Power state to put each device in.
+ *
+ *	Walk the dpm_active list, call ->suspend() for each device, and move
+ *	it to the dpm_off list.
+ *
+ *	(For historical reasons, if it returns -EAGAIN, that used to mean
+ *	that the device would be called again with interrupts disabled.
+ *	These days, we use the "suspend_late()" callback for that, so we
+ *	print a warning and consider it an error).
+ *
+ *	If we get a different error, try and back out.
+ *
+ *	If we hit a failure with any of the devices, call device_resume()
+ *	above to bring the suspended devices back to life.
+ *
+ */
+
+int device_suspend(pm_message_t state)
+{
+	int error = 0;
+
+	might_sleep();
+	down(&dpm_sem);
+	down(&dpm_list_sem);
+	while (!list_empty(&dpm_active) && error == 0) {
+		struct list_head * entry = dpm_active.prev;
+		struct device * dev = to_device(entry);
+
+		get_device(dev);
+		up(&dpm_list_sem);
+
+#ifdef CONFIG_PM_CPU_MODE
+        if(pm_cpu_mode == 0){
+		    error = suspend_device(dev, state);
+        }
+        else{
+//		    suspend_device(dev, state);
+        }
+#else
+		error = suspend_device(dev, state);
+#endif
+
+		down(&dpm_list_sem);
+
+		/* Check if the device got removed */
+		if (!list_empty(&dev->power.entry)) {
+			/* Move it to the dpm_off list */
+			if (!error)
+				list_move(&dev->power.entry, &dpm_off);
+		}
+		if (error)
+			printk(KERN_ERR "Could not suspend device %s: "
+				"error %d%s\n",
+				kobject_name(&dev->kobj), error,
+				error == -EAGAIN ? " (please convert to suspend_late)" : "");
+		put_device(dev);
+	}
+	up(&dpm_list_sem);
+	if (error)
+		dpm_resume();
+
+	up(&dpm_sem);
+	return error;
+}
+
+EXPORT_SYMBOL_GPL(device_suspend);
+
+/**
+ *	device_power_down - Shut down special devices.
+ *	@state:		Power state to enter.
+ *
+ *	Walk the dpm_off_irq list, calling ->power_down() for each device that
+ *	couldn't power down the device with interrupts enabled. When we're
+ *	done, power down system devices.
+ */
+
+int device_power_down(pm_message_t state)
+{
+	int error = 0;
+	struct device * dev;
+
+	while (!list_empty(&dpm_off)) {
+		struct list_head * entry = dpm_off.prev;
+
+		dev = to_device(entry);
+		error = suspend_device_late(dev, state);
+		if (error)
+			goto Error;
+		list_move(&dev->power.entry, &dpm_off_irq);
+	}
+
+	error = sysdev_suspend(state);
+ Done:
+	return error;
+ Error:
+	printk(KERN_ERR "Could not power down device %s: "
+		"error %d\n", kobject_name(&dev->kobj), error);
+	dpm_power_up();
+	goto Done;
+}
+
+EXPORT_SYMBOL_GPL(device_power_down);
+
+void __suspend_report_result(const char *function, void *fn, int ret)
+{
+	if (ret) {
+		printk(KERN_ERR "%s(): ", function);
+		print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn);
+		printk("%d\n", ret);
+	}
+}
+EXPORT_SYMBOL_GPL(__suspend_report_result);

drivers/base/power/sysfs.c

@@ -0,0 +1,165 @@
+/*
+ * drivers/base/power/sysfs.c - sysfs entries for device PM
+ */
+
+#include <linux/device.h>
+#include <linux/string.h>
+#include "power.h"
+
+
+#ifdef	CONFIG_PM_SYSFS_DEPRECATED
+
+/**
+ *	state - Control current power state of device
+ *
+ *	show() returns the current power state of the device. '0' indicates
+ *	the device is on. Other values (2) indicate the device is in some low
+ *	power state.
+ *
+ *	store() sets the current power state, which is an integer valued
+ *	0, 2, or 3.  Devices with bus.suspend_late(), or bus.resume_early()
+ *	methods fail this operation; those methods couldn't be called.
+ *	Otherwise,
+ *
+ *	- If the recorded dev->power.power_state.event matches the
+ *	  target value, nothing is done.
+ *	- If the recorded event code is nonzero, the device is reactivated
+ *	  by calling bus.resume() and/or class.resume().
+ *	- If the target value is nonzero, the device is suspended by
+ *	  calling class.suspend() and/or bus.suspend() with event code
+ *	  PM_EVENT_SUSPEND.
+ *
+ *	This mechanism is DEPRECATED and should only be used for testing.
+ */
+
+static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
+{
+	if (dev->power.power_state.event)
+		return sprintf(buf, "2\n");
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t state_store(struct device * dev, struct device_attribute *attr, const char * buf, size_t n)
+{
+	pm_message_t state;
+	int error = -EINVAL;
+
+	/* disallow incomplete suspend sequences */
+	if (dev->bus && (dev->bus->suspend_late || dev->bus->resume_early))
+		return error;
+
+	state.event = PM_EVENT_SUSPEND;
+	/* Older apps expected to write "3" here - confused with PCI D3 */
+	if ((n == 1) && !strcmp(buf, "3"))
+		error = dpm_runtime_suspend(dev, state);
+
+	if ((n == 1) && !strcmp(buf, "2"))
+		error = dpm_runtime_suspend(dev, state);
+
+	if ((n == 1) && !strcmp(buf, "0")) {
+		dpm_runtime_resume(dev);
+		error = 0;
+	}
+
+	return error ? error : n;
+}
+
+static DEVICE_ATTR(state, 0644, state_show, state_store);
+
+
+#endif	/* CONFIG_PM_SYSFS_DEPRECATED */
+
+/*
+ *	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[] = {
+#ifdef	CONFIG_PM_SYSFS_DEPRECATED
+	&dev_attr_state.attr,
+#endif
+	&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);
+}

drivers/base/power/trace.c

@@ -0,0 +1,228 @@
+/*
+ * 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, time.tm_mday, time.tm_year);
+	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);
+}
+
+/*
+ * 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(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);
+}
+
+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 += 6) {
+		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_active.prev;
+
+	while (entry != &dpm_active) {
+		struct device * dev = to_device(entry);
+		unsigned int hash = hash_string(DEVSEED, dev->bus_id, DEVHASH);
+		if (hash == value) {
+			printk("  hash matches device %s\n", dev->bus_id);
+			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);