// SPDX-License-Identifier: GPL-2.0
/*
 * Wakeup statistics in sysfs
 *
 * Copyright (c) 2019 Linux Foundation
 * Copyright (c) 2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 * Copyright (c) 2019 Google Inc.
 */

#include <linux/device.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/slab.h>
#include <linux/timekeeping.h>

#include "power.h"

static struct class *wakeup_class;

#define wakeup_attr(_name)                                              \
static ssize_t _name##_show(struct device *dev,                         \
                            struct device_attribute *attr, char *buf)   \
{                                                                       \
        struct wakeup_source *ws = dev_get_drvdata(dev);                \
                                                                        \
        return sysfs_emit(buf, "%lu\n", ws->_name);                     \
}                                                                       \
static DEVICE_ATTR_RO(_name)

wakeup_attr(active_count);
wakeup_attr(event_count);
wakeup_attr(wakeup_count);
wakeup_attr(expire_count);
wakeup_attr(relax_count);

static ssize_t active_time_ms_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);
        ktime_t active_time =
                ws->active ? ktime_sub(ktime_get(), ws->last_time) : 0;

        return sysfs_emit(buf, "%lld\n", ktime_to_ms(active_time));
}
static DEVICE_ATTR_RO(active_time_ms);

static ssize_t total_time_ms_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);
        ktime_t active_time;
        ktime_t total_time = ws->total_time;

        if (ws->active) {
                active_time = ktime_sub(ktime_get(), ws->last_time);
                total_time = ktime_add(total_time, active_time);
        }

        return sysfs_emit(buf, "%lld\n", ktime_to_ms(total_time));
}
static DEVICE_ATTR_RO(total_time_ms);

static ssize_t max_time_ms_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);
        ktime_t active_time;
        ktime_t max_time = ws->max_time;

        if (ws->active) {
                active_time = ktime_sub(ktime_get(), ws->last_time);
                if (active_time > max_time)
                        max_time = active_time;
        }

        return sysfs_emit(buf, "%lld\n", ktime_to_ms(max_time));
}
static DEVICE_ATTR_RO(max_time_ms);

static ssize_t last_change_ms_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%lld\n", ktime_to_ms(ws->last_time));
}
static DEVICE_ATTR_RO(last_change_ms);

static ssize_t name_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%s\n", ws->name);
}
static DEVICE_ATTR_RO(name);

static ssize_t prevent_suspend_time_ms_show(struct device *dev,
                                            struct device_attribute *attr,
                                            char *buf)
{
        struct wakeup_source *ws = dev_get_drvdata(dev);
        ktime_t prevent_sleep_time = ws->prevent_sleep_time;

        if (ws->active && ws->autosleep_enabled) {
                prevent_sleep_time = ktime_add(prevent_sleep_time,
                        ktime_sub(ktime_get(), ws->start_prevent_time));
        }

        return sysfs_emit(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
}
static DEVICE_ATTR_RO(prevent_suspend_time_ms);

static struct attribute *wakeup_source_attrs[] = {
        &dev_attr_name.attr,
        &dev_attr_active_count.attr,
        &dev_attr_event_count.attr,
        &dev_attr_wakeup_count.attr,
        &dev_attr_expire_count.attr,
        &dev_attr_relax_count.attr,
        &dev_attr_active_time_ms.attr,
        &dev_attr_total_time_ms.attr,
        &dev_attr_max_time_ms.attr,
        &dev_attr_last_change_ms.attr,
        &dev_attr_prevent_suspend_time_ms.attr,
        NULL,
};
ATTRIBUTE_GROUPS(wakeup_source);

static void device_create_release(struct device *dev)
{
        kfree(dev);
}

static struct device *wakeup_source_device_create(struct device *parent,
                                                  struct wakeup_source *ws)
{
        struct device *dev = NULL;
        int retval;

        dev = kzalloc_obj(*dev);
        if (!dev) {
                retval = -ENOMEM;
                goto error;
        }

        device_initialize(dev);
        dev->devt = MKDEV(0, 0);
        dev->class = wakeup_class;
        dev->parent = parent;
        dev->groups = wakeup_source_groups;
        dev->release = device_create_release;
        dev_set_drvdata(dev, ws);
        device_set_pm_not_required(dev);

        retval = dev_set_name(dev, "wakeup%d", ws->id);
        if (retval)
                goto error;

        retval = device_add(dev);
        if (retval)
                goto error;

        return dev;

error:
        put_device(dev);
        return ERR_PTR(retval);
}

/**
 * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
 * @parent: Device given wakeup source is associated with (or NULL if virtual).
 * @ws: Wakeup source to be added in sysfs.
 */
int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
{
        struct device *dev;

        dev = wakeup_source_device_create(parent, ws);
        if (IS_ERR(dev))
                return PTR_ERR(dev);
        ws->dev = dev;

        return 0;
}

/**
 * pm_wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs
 * for a device if they're missing.
 * @parent: Device given wakeup source is associated with
 */
int pm_wakeup_source_sysfs_add(struct device *parent)
{
        if (!parent->power.wakeup || parent->power.wakeup->dev)
                return 0;

        return wakeup_source_sysfs_add(parent, parent->power.wakeup);
}

/**
 * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
 * @ws: Wakeup source to be removed from sysfs.
 */
void wakeup_source_sysfs_remove(struct wakeup_source *ws)
{
        device_unregister(ws->dev);
}

static int __init wakeup_sources_sysfs_init(void)
{
        wakeup_class = class_create("wakeup");

        return PTR_ERR_OR_ZERO(wakeup_class);
}
postcore_initcall(wakeup_sources_sysfs_init);