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/*

 * 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 <linux/kallsyms.h>

#include <linux/mutex.h>

#include <linux/pm.h>

#include <linux/resume-trace.h>

#include "../base.h"

#include "power.h"

LIST_HEAD(dpm_active);

static LIST_HEAD(dpm_off);

static LIST_HEAD(dpm_off_irq);

static DEFINE_MUTEX(dpm_mtx);

static DEFINE_MUTEX(dpm_list_mtx);

int (*platform_enable_wakeup)(struct device *dev, int is_on);

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);

        list_add_tail(&dev->power.entry, &dpm_active);

        mutex_unlock(&dpm_list_mtx);

}

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);

        dpm_sysfs_remove(dev);

        list_del_init(&dev->power.entry);

        mutex_unlock(&dpm_list_mtx);

}

/*------------------------- Resume routines -------------------------*/

/**

 *      resume_device - Restore state for one device.

 *      @dev:   Device.

 *

 */

static int resume_device(struct device * dev)

{

        int error = 0;

        TRACE_DEVICE(dev);

        TRACE_RESUME(0);

        down(&dev->sem);

        if (dev->bus && dev->bus->resume) {

                dev_dbg(dev,"resuming\n");

                error = dev->bus->resume(dev);

        }

        if (!error && dev->type && dev->type->resume) {

                dev_dbg(dev,"resuming\n");

                error = dev->type->resume(dev);

        }

        if (!error && 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

 */

static void dpm_resume(void)

{

        mutex_lock(&dpm_list_mtx);

        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);

                mutex_unlock(&dpm_list_mtx);

                resume_device(dev);

                mutex_lock(&dpm_list_mtx);

                put_device(dev);

        }

        mutex_unlock(&dpm_list_mtx);

}

/**

 *      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();

        mutex_lock(&dpm_mtx);

        dpm_resume();

        mutex_unlock(&dpm_mtx);

}

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.

 */

static 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);

/*------------------------- Suspend routines -------------------------*/

/*

 * 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)";

        }

}

static void

suspend_device_dbg(struct device *dev, pm_message_t state, char *info)

{

        dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),

                ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?

                ", may wakeup" : "");

}

/**

 *      suspend_device - Save state of one device.

 *      @dev:   Device.

 *      @state: Power state device is entering.

 */

static 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->class && dev->class->suspend) {

                suspend_device_dbg(dev, state, "class ");

                error = dev->class->suspend(dev, state);

                suspend_report_result(dev->class->suspend, error);

        }

        if (!error && dev->type && dev->type->suspend) {

                suspend_device_dbg(dev, state, "type ");

                error = dev->type->suspend(dev, state);

                suspend_report_result(dev->type->suspend, error);

        }

        if (!error && dev->bus && dev->bus->suspend) {

                suspend_device_dbg(dev, state, "");

                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 acquire a mutex or 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) {

                suspend_device_dbg(dev, state, "LATE ");

                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();

        mutex_lock(&dpm_mtx);

        mutex_lock(&dpm_list_mtx);

        while (!list_empty(&dpm_active) && error == 0) {

                struct list_head * entry = dpm_active.prev;

                struct device * dev = to_device(entry);

                get_device(dev);

                mutex_unlock(&dpm_list_mtx);

                error = suspend_device(dev, state);

                mutex_lock(&dpm_list_mtx);

                /* 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);

        }

        mutex_unlock(&dpm_list_mtx);

        if (error)

                dpm_resume();

        mutex_unlock(&dpm_mtx);

        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);