mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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890 lines
22 KiB
C
890 lines
22 KiB
C
/*
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* RTC subsystem, interface functions
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*
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* Copyright (C) 2005 Tower Technologies
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* Author: Alessandro Zummo <a.zummo@towertech.it>
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*
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* based on arch/arm/common/rtctime.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/rtc.h>
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#include <linux/sched.h>
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#include <linux/log2.h>
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#include <linux/workqueue.h>
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static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
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static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
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static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
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{
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int err;
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if (!rtc->ops)
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err = -ENODEV;
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else if (!rtc->ops->read_time)
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err = -EINVAL;
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else {
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memset(tm, 0, sizeof(struct rtc_time));
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err = rtc->ops->read_time(rtc->dev.parent, tm);
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}
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return err;
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}
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int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
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{
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int err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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err = __rtc_read_time(rtc, tm);
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_read_time);
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int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
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{
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int err;
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err = rtc_valid_tm(tm);
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if (err != 0)
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return err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (!rtc->ops)
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err = -ENODEV;
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else if (rtc->ops->set_time)
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err = rtc->ops->set_time(rtc->dev.parent, tm);
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else if (rtc->ops->set_mmss) {
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unsigned long secs;
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err = rtc_tm_to_time(tm, &secs);
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if (err == 0)
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err = rtc->ops->set_mmss(rtc->dev.parent, secs);
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} else
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err = -EINVAL;
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_set_time);
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int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
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{
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int err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (!rtc->ops)
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err = -ENODEV;
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else if (rtc->ops->set_mmss)
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err = rtc->ops->set_mmss(rtc->dev.parent, secs);
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else if (rtc->ops->read_time && rtc->ops->set_time) {
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struct rtc_time new, old;
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err = rtc->ops->read_time(rtc->dev.parent, &old);
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if (err == 0) {
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rtc_time_to_tm(secs, &new);
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/*
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* avoid writing when we're going to change the day of
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* the month. We will retry in the next minute. This
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* basically means that if the RTC must not drift
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* by more than 1 minute in 11 minutes.
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*/
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if (!((old.tm_hour == 23 && old.tm_min == 59) ||
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(new.tm_hour == 23 && new.tm_min == 59)))
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err = rtc->ops->set_time(rtc->dev.parent,
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&new);
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}
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}
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else
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err = -EINVAL;
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_set_mmss);
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static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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int err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (rtc->ops == NULL)
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err = -ENODEV;
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else if (!rtc->ops->read_alarm)
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err = -EINVAL;
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else {
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memset(alarm, 0, sizeof(struct rtc_wkalrm));
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err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
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}
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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int err;
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struct rtc_time before, now;
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int first_time = 1;
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unsigned long t_now, t_alm;
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enum { none, day, month, year } missing = none;
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unsigned days;
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/* The lower level RTC driver may return -1 in some fields,
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* creating invalid alarm->time values, for reasons like:
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*
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* - The hardware may not be capable of filling them in;
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* many alarms match only on time-of-day fields, not
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* day/month/year calendar data.
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*
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* - Some hardware uses illegal values as "wildcard" match
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* values, which non-Linux firmware (like a BIOS) may try
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* to set up as e.g. "alarm 15 minutes after each hour".
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* Linux uses only oneshot alarms.
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*
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* When we see that here, we deal with it by using values from
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* a current RTC timestamp for any missing (-1) values. The
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* RTC driver prevents "periodic alarm" modes.
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*
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* But this can be racey, because some fields of the RTC timestamp
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* may have wrapped in the interval since we read the RTC alarm,
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* which would lead to us inserting inconsistent values in place
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* of the -1 fields.
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*
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* Reading the alarm and timestamp in the reverse sequence
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* would have the same race condition, and not solve the issue.
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*
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* So, we must first read the RTC timestamp,
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* then read the RTC alarm value,
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* and then read a second RTC timestamp.
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*
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* If any fields of the second timestamp have changed
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* when compared with the first timestamp, then we know
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* our timestamp may be inconsistent with that used by
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* the low-level rtc_read_alarm_internal() function.
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*
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* So, when the two timestamps disagree, we just loop and do
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* the process again to get a fully consistent set of values.
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*
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* This could all instead be done in the lower level driver,
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* but since more than one lower level RTC implementation needs it,
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* then it's probably best best to do it here instead of there..
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*/
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/* Get the "before" timestamp */
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err = rtc_read_time(rtc, &before);
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if (err < 0)
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return err;
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do {
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if (!first_time)
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memcpy(&before, &now, sizeof(struct rtc_time));
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first_time = 0;
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/* get the RTC alarm values, which may be incomplete */
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err = rtc_read_alarm_internal(rtc, alarm);
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if (err)
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return err;
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/* full-function RTCs won't have such missing fields */
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if (rtc_valid_tm(&alarm->time) == 0)
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return 0;
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/* get the "after" timestamp, to detect wrapped fields */
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err = rtc_read_time(rtc, &now);
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if (err < 0)
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return err;
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/* note that tm_sec is a "don't care" value here: */
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} while ( before.tm_min != now.tm_min
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|| before.tm_hour != now.tm_hour
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|| before.tm_mon != now.tm_mon
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|| before.tm_year != now.tm_year);
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/* Fill in the missing alarm fields using the timestamp; we
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* know there's at least one since alarm->time is invalid.
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*/
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if (alarm->time.tm_sec == -1)
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alarm->time.tm_sec = now.tm_sec;
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if (alarm->time.tm_min == -1)
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alarm->time.tm_min = now.tm_min;
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if (alarm->time.tm_hour == -1)
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alarm->time.tm_hour = now.tm_hour;
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/* For simplicity, only support date rollover for now */
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if (alarm->time.tm_mday == -1) {
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alarm->time.tm_mday = now.tm_mday;
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missing = day;
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}
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if (alarm->time.tm_mon == -1) {
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alarm->time.tm_mon = now.tm_mon;
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if (missing == none)
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missing = month;
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}
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if (alarm->time.tm_year == -1) {
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alarm->time.tm_year = now.tm_year;
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if (missing == none)
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missing = year;
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}
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/* with luck, no rollover is needed */
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rtc_tm_to_time(&now, &t_now);
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rtc_tm_to_time(&alarm->time, &t_alm);
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if (t_now < t_alm)
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goto done;
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switch (missing) {
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/* 24 hour rollover ... if it's now 10am Monday, an alarm that
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* that will trigger at 5am will do so at 5am Tuesday, which
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* could also be in the next month or year. This is a common
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* case, especially for PCs.
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*/
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case day:
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dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
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t_alm += 24 * 60 * 60;
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rtc_time_to_tm(t_alm, &alarm->time);
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break;
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/* Month rollover ... if it's the 31th, an alarm on the 3rd will
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* be next month. An alarm matching on the 30th, 29th, or 28th
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* may end up in the month after that! Many newer PCs support
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* this type of alarm.
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*/
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case month:
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dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
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do {
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if (alarm->time.tm_mon < 11)
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alarm->time.tm_mon++;
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else {
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alarm->time.tm_mon = 0;
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alarm->time.tm_year++;
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}
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days = rtc_month_days(alarm->time.tm_mon,
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alarm->time.tm_year);
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} while (days < alarm->time.tm_mday);
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break;
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/* Year rollover ... easy except for leap years! */
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case year:
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dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
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do {
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alarm->time.tm_year++;
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} while (rtc_valid_tm(&alarm->time) != 0);
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break;
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default:
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dev_warn(&rtc->dev, "alarm rollover not handled\n");
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}
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done:
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return 0;
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}
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int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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int err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (rtc->ops == NULL)
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err = -ENODEV;
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else if (!rtc->ops->read_alarm)
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err = -EINVAL;
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else {
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memset(alarm, 0, sizeof(struct rtc_wkalrm));
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alarm->enabled = rtc->aie_timer.enabled;
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alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
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}
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_read_alarm);
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int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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struct rtc_time tm;
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long now, scheduled;
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int err;
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err = rtc_valid_tm(&alarm->time);
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if (err)
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return err;
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rtc_tm_to_time(&alarm->time, &scheduled);
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/* Make sure we're not setting alarms in the past */
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err = __rtc_read_time(rtc, &tm);
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rtc_tm_to_time(&tm, &now);
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if (scheduled <= now)
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return -ETIME;
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/*
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* XXX - We just checked to make sure the alarm time is not
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* in the past, but there is still a race window where if
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* the is alarm set for the next second and the second ticks
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* over right here, before we set the alarm.
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*/
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if (!rtc->ops)
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err = -ENODEV;
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else if (!rtc->ops->set_alarm)
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err = -EINVAL;
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else
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err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
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return err;
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}
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int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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int err;
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err = rtc_valid_tm(&alarm->time);
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if (err != 0)
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return err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (rtc->aie_timer.enabled) {
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rtc_timer_remove(rtc, &rtc->aie_timer);
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}
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rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
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rtc->aie_timer.period = ktime_set(0, 0);
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if (alarm->enabled) {
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err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
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}
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_set_alarm);
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/* Called once per device from rtc_device_register */
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int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
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{
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int err;
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err = rtc_valid_tm(&alarm->time);
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if (err != 0)
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return err;
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err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
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rtc->aie_timer.period = ktime_set(0, 0);
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if (alarm->enabled) {
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rtc->aie_timer.enabled = 1;
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timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
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}
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
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int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
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{
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int err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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if (rtc->aie_timer.enabled != enabled) {
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if (enabled)
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err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
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else
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rtc_timer_remove(rtc, &rtc->aie_timer);
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}
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if (err)
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/* nothing */;
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else if (!rtc->ops)
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err = -ENODEV;
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else if (!rtc->ops->alarm_irq_enable)
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err = -EINVAL;
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else
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err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
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mutex_unlock(&rtc->ops_lock);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
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int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
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{
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int err = mutex_lock_interruptible(&rtc->ops_lock);
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if (err)
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return err;
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#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
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if (enabled == 0 && rtc->uie_irq_active) {
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mutex_unlock(&rtc->ops_lock);
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return rtc_dev_update_irq_enable_emul(rtc, 0);
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}
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#endif
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/* make sure we're changing state */
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if (rtc->uie_rtctimer.enabled == enabled)
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goto out;
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if (enabled) {
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struct rtc_time tm;
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ktime_t now, onesec;
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__rtc_read_time(rtc, &tm);
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onesec = ktime_set(1, 0);
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now = rtc_tm_to_ktime(tm);
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rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
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rtc->uie_rtctimer.period = ktime_set(1, 0);
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err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
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} else
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rtc_timer_remove(rtc, &rtc->uie_rtctimer);
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out:
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mutex_unlock(&rtc->ops_lock);
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#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
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/*
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* Enable emulation if the driver did not provide
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* the update_irq_enable function pointer or if returned
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* -EINVAL to signal that it has been configured without
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* interrupts or that are not available at the moment.
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*/
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if (err == -EINVAL)
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err = rtc_dev_update_irq_enable_emul(rtc, enabled);
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#endif
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
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|
|
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/**
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* rtc_handle_legacy_irq - AIE, UIE and PIE event hook
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* @rtc: pointer to the rtc device
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*
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* This function is called when an AIE, UIE or PIE mode interrupt
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* has occurred (or been emulated).
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*
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* Triggers the registered irq_task function callback.
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*/
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void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
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{
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unsigned long flags;
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|
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/* mark one irq of the appropriate mode */
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spin_lock_irqsave(&rtc->irq_lock, flags);
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rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
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spin_unlock_irqrestore(&rtc->irq_lock, flags);
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|
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/* call the task func */
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spin_lock_irqsave(&rtc->irq_task_lock, flags);
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if (rtc->irq_task)
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rtc->irq_task->func(rtc->irq_task->private_data);
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spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
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wake_up_interruptible(&rtc->irq_queue);
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kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
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}
|
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|
|
|
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/**
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* rtc_aie_update_irq - AIE mode rtctimer hook
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* @private: pointer to the rtc_device
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*
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* This functions is called when the aie_timer expires.
|
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*/
|
|
void rtc_aie_update_irq(void *private)
|
|
{
|
|
struct rtc_device *rtc = (struct rtc_device *)private;
|
|
rtc_handle_legacy_irq(rtc, 1, RTC_AF);
|
|
}
|
|
|
|
|
|
/**
|
|
* rtc_uie_update_irq - UIE mode rtctimer hook
|
|
* @private: pointer to the rtc_device
|
|
*
|
|
* This functions is called when the uie_timer expires.
|
|
*/
|
|
void rtc_uie_update_irq(void *private)
|
|
{
|
|
struct rtc_device *rtc = (struct rtc_device *)private;
|
|
rtc_handle_legacy_irq(rtc, 1, RTC_UF);
|
|
}
|
|
|
|
|
|
/**
|
|
* rtc_pie_update_irq - PIE mode hrtimer hook
|
|
* @timer: pointer to the pie mode hrtimer
|
|
*
|
|
* This function is used to emulate PIE mode interrupts
|
|
* using an hrtimer. This function is called when the periodic
|
|
* hrtimer expires.
|
|
*/
|
|
enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
|
|
{
|
|
struct rtc_device *rtc;
|
|
ktime_t period;
|
|
int count;
|
|
rtc = container_of(timer, struct rtc_device, pie_timer);
|
|
|
|
period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
|
|
count = hrtimer_forward_now(timer, period);
|
|
|
|
rtc_handle_legacy_irq(rtc, count, RTC_PF);
|
|
|
|
return HRTIMER_RESTART;
|
|
}
|
|
|
|
/**
|
|
* rtc_update_irq - Triggered when a RTC interrupt occurs.
|
|
* @rtc: the rtc device
|
|
* @num: how many irqs are being reported (usually one)
|
|
* @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
|
|
* Context: any
|
|
*/
|
|
void rtc_update_irq(struct rtc_device *rtc,
|
|
unsigned long num, unsigned long events)
|
|
{
|
|
schedule_work(&rtc->irqwork);
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_update_irq);
|
|
|
|
static int __rtc_match(struct device *dev, void *data)
|
|
{
|
|
char *name = (char *)data;
|
|
|
|
if (strcmp(dev_name(dev), name) == 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
struct rtc_device *rtc_class_open(char *name)
|
|
{
|
|
struct device *dev;
|
|
struct rtc_device *rtc = NULL;
|
|
|
|
dev = class_find_device(rtc_class, NULL, name, __rtc_match);
|
|
if (dev)
|
|
rtc = to_rtc_device(dev);
|
|
|
|
if (rtc) {
|
|
if (!try_module_get(rtc->owner)) {
|
|
put_device(dev);
|
|
rtc = NULL;
|
|
}
|
|
}
|
|
|
|
return rtc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_class_open);
|
|
|
|
void rtc_class_close(struct rtc_device *rtc)
|
|
{
|
|
module_put(rtc->owner);
|
|
put_device(&rtc->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_class_close);
|
|
|
|
int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
|
|
{
|
|
int retval = -EBUSY;
|
|
|
|
if (task == NULL || task->func == NULL)
|
|
return -EINVAL;
|
|
|
|
/* Cannot register while the char dev is in use */
|
|
if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
|
|
return -EBUSY;
|
|
|
|
spin_lock_irq(&rtc->irq_task_lock);
|
|
if (rtc->irq_task == NULL) {
|
|
rtc->irq_task = task;
|
|
retval = 0;
|
|
}
|
|
spin_unlock_irq(&rtc->irq_task_lock);
|
|
|
|
clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_irq_register);
|
|
|
|
void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
|
|
{
|
|
spin_lock_irq(&rtc->irq_task_lock);
|
|
if (rtc->irq_task == task)
|
|
rtc->irq_task = NULL;
|
|
spin_unlock_irq(&rtc->irq_task_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_irq_unregister);
|
|
|
|
/**
|
|
* rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
|
|
* @rtc: the rtc device
|
|
* @task: currently registered with rtc_irq_register()
|
|
* @enabled: true to enable periodic IRQs
|
|
* Context: any
|
|
*
|
|
* Note that rtc_irq_set_freq() should previously have been used to
|
|
* specify the desired frequency of periodic IRQ task->func() callbacks.
|
|
*/
|
|
int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
|
|
{
|
|
int err = 0;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&rtc->irq_task_lock, flags);
|
|
if (rtc->irq_task != NULL && task == NULL)
|
|
err = -EBUSY;
|
|
if (rtc->irq_task != task)
|
|
err = -EACCES;
|
|
|
|
if (enabled) {
|
|
ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
|
|
hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
|
|
} else {
|
|
hrtimer_cancel(&rtc->pie_timer);
|
|
}
|
|
rtc->pie_enabled = enabled;
|
|
spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_irq_set_state);
|
|
|
|
/**
|
|
* rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
|
|
* @rtc: the rtc device
|
|
* @task: currently registered with rtc_irq_register()
|
|
* @freq: positive frequency with which task->func() will be called
|
|
* Context: any
|
|
*
|
|
* Note that rtc_irq_set_state() is used to enable or disable the
|
|
* periodic IRQs.
|
|
*/
|
|
int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
|
|
{
|
|
int err = 0;
|
|
unsigned long flags;
|
|
|
|
if (freq <= 0)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&rtc->irq_task_lock, flags);
|
|
if (rtc->irq_task != NULL && task == NULL)
|
|
err = -EBUSY;
|
|
if (rtc->irq_task != task)
|
|
err = -EACCES;
|
|
if (err == 0) {
|
|
rtc->irq_freq = freq;
|
|
if (rtc->pie_enabled) {
|
|
ktime_t period;
|
|
hrtimer_cancel(&rtc->pie_timer);
|
|
period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
|
|
hrtimer_start(&rtc->pie_timer, period,
|
|
HRTIMER_MODE_REL);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
|
|
|
|
/**
|
|
* rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
|
|
* @rtc rtc device
|
|
* @timer timer being added.
|
|
*
|
|
* Enqueues a timer onto the rtc devices timerqueue and sets
|
|
* the next alarm event appropriately.
|
|
*
|
|
* Sets the enabled bit on the added timer.
|
|
*
|
|
* Must hold ops_lock for proper serialization of timerqueue
|
|
*/
|
|
static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
|
|
{
|
|
timer->enabled = 1;
|
|
timerqueue_add(&rtc->timerqueue, &timer->node);
|
|
if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
|
|
struct rtc_wkalrm alarm;
|
|
int err;
|
|
alarm.time = rtc_ktime_to_tm(timer->node.expires);
|
|
alarm.enabled = 1;
|
|
err = __rtc_set_alarm(rtc, &alarm);
|
|
if (err == -ETIME)
|
|
schedule_work(&rtc->irqwork);
|
|
else if (err) {
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
timer->enabled = 0;
|
|
return err;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
|
|
* @rtc rtc device
|
|
* @timer timer being removed.
|
|
*
|
|
* Removes a timer onto the rtc devices timerqueue and sets
|
|
* the next alarm event appropriately.
|
|
*
|
|
* Clears the enabled bit on the removed timer.
|
|
*
|
|
* Must hold ops_lock for proper serialization of timerqueue
|
|
*/
|
|
static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
|
|
{
|
|
struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
timer->enabled = 0;
|
|
if (next == &timer->node) {
|
|
struct rtc_wkalrm alarm;
|
|
int err;
|
|
next = timerqueue_getnext(&rtc->timerqueue);
|
|
if (!next)
|
|
return;
|
|
alarm.time = rtc_ktime_to_tm(next->expires);
|
|
alarm.enabled = 1;
|
|
err = __rtc_set_alarm(rtc, &alarm);
|
|
if (err == -ETIME)
|
|
schedule_work(&rtc->irqwork);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* rtc_timer_do_work - Expires rtc timers
|
|
* @rtc rtc device
|
|
* @timer timer being removed.
|
|
*
|
|
* Expires rtc timers. Reprograms next alarm event if needed.
|
|
* Called via worktask.
|
|
*
|
|
* Serializes access to timerqueue via ops_lock mutex
|
|
*/
|
|
void rtc_timer_do_work(struct work_struct *work)
|
|
{
|
|
struct rtc_timer *timer;
|
|
struct timerqueue_node *next;
|
|
ktime_t now;
|
|
struct rtc_time tm;
|
|
|
|
struct rtc_device *rtc =
|
|
container_of(work, struct rtc_device, irqwork);
|
|
|
|
mutex_lock(&rtc->ops_lock);
|
|
again:
|
|
__rtc_read_time(rtc, &tm);
|
|
now = rtc_tm_to_ktime(tm);
|
|
while ((next = timerqueue_getnext(&rtc->timerqueue))) {
|
|
if (next->expires.tv64 > now.tv64)
|
|
break;
|
|
|
|
/* expire timer */
|
|
timer = container_of(next, struct rtc_timer, node);
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
timer->enabled = 0;
|
|
if (timer->task.func)
|
|
timer->task.func(timer->task.private_data);
|
|
|
|
/* Re-add/fwd periodic timers */
|
|
if (ktime_to_ns(timer->period)) {
|
|
timer->node.expires = ktime_add(timer->node.expires,
|
|
timer->period);
|
|
timer->enabled = 1;
|
|
timerqueue_add(&rtc->timerqueue, &timer->node);
|
|
}
|
|
}
|
|
|
|
/* Set next alarm */
|
|
if (next) {
|
|
struct rtc_wkalrm alarm;
|
|
int err;
|
|
alarm.time = rtc_ktime_to_tm(next->expires);
|
|
alarm.enabled = 1;
|
|
err = __rtc_set_alarm(rtc, &alarm);
|
|
if (err == -ETIME)
|
|
goto again;
|
|
}
|
|
|
|
mutex_unlock(&rtc->ops_lock);
|
|
}
|
|
|
|
|
|
/* rtc_timer_init - Initializes an rtc_timer
|
|
* @timer: timer to be intiialized
|
|
* @f: function pointer to be called when timer fires
|
|
* @data: private data passed to function pointer
|
|
*
|
|
* Kernel interface to initializing an rtc_timer.
|
|
*/
|
|
void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data)
|
|
{
|
|
timerqueue_init(&timer->node);
|
|
timer->enabled = 0;
|
|
timer->task.func = f;
|
|
timer->task.private_data = data;
|
|
}
|
|
|
|
/* rtc_timer_start - Sets an rtc_timer to fire in the future
|
|
* @ rtc: rtc device to be used
|
|
* @ timer: timer being set
|
|
* @ expires: time at which to expire the timer
|
|
* @ period: period that the timer will recur
|
|
*
|
|
* Kernel interface to set an rtc_timer
|
|
*/
|
|
int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer,
|
|
ktime_t expires, ktime_t period)
|
|
{
|
|
int ret = 0;
|
|
mutex_lock(&rtc->ops_lock);
|
|
if (timer->enabled)
|
|
rtc_timer_remove(rtc, timer);
|
|
|
|
timer->node.expires = expires;
|
|
timer->period = period;
|
|
|
|
ret = rtc_timer_enqueue(rtc, timer);
|
|
|
|
mutex_unlock(&rtc->ops_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* rtc_timer_cancel - Stops an rtc_timer
|
|
* @ rtc: rtc device to be used
|
|
* @ timer: timer being set
|
|
*
|
|
* Kernel interface to cancel an rtc_timer
|
|
*/
|
|
int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer)
|
|
{
|
|
int ret = 0;
|
|
mutex_lock(&rtc->ops_lock);
|
|
if (timer->enabled)
|
|
rtc_timer_remove(rtc, timer);
|
|
mutex_unlock(&rtc->ops_lock);
|
|
return ret;
|
|
}
|
|
|
|
|