/*
* RTC subsystem, interface functions
*
* Copyright (C) 2005 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* based on arch/arm/common/rtctime.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/rtc.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/log2.h>
#include <linux/workqueue.h>
static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
{
int err;
if (!rtc->ops)
err = -ENODEV;
else if (!rtc->ops->read_time)
err = -EINVAL;
else {
memset(tm, 0, sizeof(struct rtc_time));
err = rtc->ops->read_time(rtc->dev.parent, tm);
if (err < 0) {
dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
err);
return err;
}
err = rtc_valid_tm(tm);
if (err < 0)
dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
}
return err;
}
int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
{
int err;
err = mutex_lock_interruptible(&rtc->ops_lock);
if (err)
return err;
err = __rtc_read_time(rtc, tm);
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_read_time);
int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
{
int err;
err = rtc_valid_tm(tm);
if (err != 0)
return err;
err = mutex_lock_interruptible(&rtc->ops_lock);
if (err)
return err;
if (!rtc->ops)
err = -ENODEV;
else if (rtc->ops->set_time)
err = rtc->ops->set_time(rtc->dev.parent, tm);
else if (rtc->ops->set_mmss64) {
time64_t secs64 = rtc_tm_to_time64(tm);
err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
} else if (rtc->ops->set_mmss) {
time64_t secs64 = rtc_tm_to_time64(tm);
err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
} else
err = -EINVAL;
pm_stay_awake(rtc->dev.parent);
mutex_unlock(&rtc->ops_lock);
/* A timer might have just expired */
schedule_work(&rtc->irqwork);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_time);
static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
int err;
err = mutex_lock_interruptible(&rtc->ops_lock);
if (err)
return err;
if (rtc->ops == NULL)
err = -ENODEV;
else if (!rtc->ops->read_alarm)
err = -EINVAL;
else {
memset(alarm, 0, sizeof(struct rtc_wkalrm));
err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
}
mutex_unlock(&rtc->ops_lock);
return err;
}
int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
int err;
struct rtc_time before, now;
int first_time = 1;
time64_t t_now, t_alm;
enum { none, day, month, year } missing = none;
unsigned days;
/* The lower level RTC driver may return -1 in some fields,
* creating invalid alarm->time values, for reasons like:
*
* - The hardware may not be capable of filling them in;
* many alarms match only on time-of-day fields, not
* day/month/year calendar data.
*
* - Some hardware uses illegal values as "wildcard" match
* values, which non-Linux firmware (like a BIOS) may try
* to set up as e.g. "alarm 15 minutes after each hour".
* Linux uses only oneshot alarms.
*
* When we see that here, we deal with it by using values from
* a current RTC timestamp for any missing (-1) values. The
* RTC driver prevents "periodic alarm" modes.
*
* But this can be racey, because some fields of the RTC timestamp
* may have wrapped in the interval since we read the RTC alarm,