linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Alarmtimer interface

 *

 * This interface provides a timer which is similarto hrtimers,

 * but triggers a RTC alarm if the box is suspend.

 *

 * This interface is influenced by the Android RTC Alarm timer

 * interface.

 *

 * Copyright (C) 2010 IBM Corperation

 *

 * Author: John Stultz <john.stultz@linaro.org>

 */

#include <linux/time.h>

#include <linux/hrtimer.h>

#include <linux/timerqueue.h>

#include <linux/rtc.h>

#include <linux/sched/signal.h>

#include <linux/sched/debug.h>

#include <linux/alarmtimer.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/posix-timers.h>

#include <linux/workqueue.h>

#include <linux/freezer.h>

#include <linux/compat.h>

#include <linux/module.h>

​

#include "posix-timers.h"

​

#define CREATE_TRACE_POINTS

#include <trace/events/alarmtimer.h>

​

/**

 * struct alarm_base - Alarm timer bases

 * @lock:       Lock for syncrhonized access to the base

 * @timerqueue:     Timerqueue head managing the list of events

 * @gettime:        Function to read the time correlating to the base

 * @base_clockid:   clockid for the base

 */

static struct alarm_base {

    spinlock_t      lock;

    struct timerqueue_head  timerqueue;

    ktime_t         (*gettime)(void);

    clockid_t       base_clockid;

} alarm_bases[ALARM_NUMTYPE];

​

#if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS)

/* freezer information to handle clock_nanosleep triggered wakeups */

static enum alarmtimer_type freezer_alarmtype;

static ktime_t freezer_expires;

static ktime_t freezer_delta;

static DEFINE_SPINLOCK(freezer_delta_lock);

#endif

​

#ifdef CONFIG_RTC_CLASS

static struct wakeup_source *ws;

​

/* rtc timer and device for setting alarm wakeups at suspend */

static struct rtc_timer     rtctimer;

static struct rtc_device    *rtcdev;

static DEFINE_SPINLOCK(rtcdev_lock);

​

/**

 * alarmtimer_get_rtcdev - Return selected rtcdevice

 *

 * This function returns the rtc device to use for wakealarms.

 * If one has not already been chosen, it checks to see if a

 * functional rtc device is available.

 */

struct rtc_device *alarmtimer_get_rtcdev(void)

{

    unsigned long flags;

    struct rtc_device *ret;

​

    spin_lock_irqsave(&rtcdev_lock, flags);

    ret = rtcdev;

    spin_unlock_irqrestore(&rtcdev_lock, flags);

​

    return ret;

}

EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);

​

static int alarmtimer_rtc_add_device(struct device *dev,

                struct class_interface *class_intf)

{

    unsigned long flags;

    struct rtc_device *rtc = to_rtc_device(dev);

    struct wakeup_source *__ws;

​

    if (rtcdev)