1057 lines
26 KiB
C
1057 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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#include <linux/rtc.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/log2.h>
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#include <linux/workqueue.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/rtc.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 void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm)
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{
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time64_t secs;
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if (!rtc->offset_secs)
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return;
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secs = rtc_tm_to_time64(tm);
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/*
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* Since the reading time values from RTC device are always in the RTC
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* original valid range, but we need to skip the overlapped region
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* between expanded range and original range, which is no need to add
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* the offset.
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*/
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if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) ||
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(rtc->start_secs < rtc->range_min &&
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secs <= (rtc->start_secs + rtc->range_max - rtc->range_min)))
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return;
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rtc_time64_to_tm(secs + rtc->offset_secs, tm);
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}
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static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm)
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{
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time64_t secs;
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if (!rtc->offset_secs)
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return;
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secs = rtc_tm_to_time64(tm);
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/*
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* If the setting time values are in the valid range of RTC hardware
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* device, then no need to subtract the offset when setting time to RTC
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* device. Otherwise we need to subtract the offset to make the time
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* values are valid for RTC hardware device.
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*/
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if (secs >= rtc->range_min && secs <= rtc->range_max)
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return;
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rtc_time64_to_tm(secs - rtc->offset_secs, tm);
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}
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static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm)
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{
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if (rtc->range_min != rtc->range_max) {
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time64_t time = rtc_tm_to_time64(tm);
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time64_t range_min = rtc->set_start_time ? rtc->start_secs :
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rtc->range_min;
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time64_t range_max = rtc->set_start_time ?
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(rtc->start_secs + rtc->range_max - rtc->range_min) :
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rtc->range_max;
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if (time < range_min || time > range_max)
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return -ERANGE;
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}
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return 0;
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}
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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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if (err < 0) {
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dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
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err);
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return err;
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}
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rtc_add_offset(rtc, tm);
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err = rtc_valid_tm(tm);
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if (err < 0)
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dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
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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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trace_rtc_read_time(rtc_tm_to_time64(tm), err);
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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 = rtc_valid_range(rtc, tm);
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if (err)
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return err;
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rtc_subtract_offset(rtc, tm);
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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
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err = -EINVAL;
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pm_stay_awake(rtc->dev.parent);
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mutex_unlock(&rtc->ops_lock);
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/* A timer might have just expired */
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schedule_work(&rtc->irqwork);
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trace_rtc_set_time(rtc_tm_to_time64(tm), err);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_set_time);
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static int rtc_read_alarm_internal(struct rtc_device *rtc,
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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) {
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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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alarm->enabled = 0;
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alarm->pending = 0;
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alarm->time.tm_sec = -1;
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alarm->time.tm_min = -1;
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alarm->time.tm_hour = -1;
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alarm->time.tm_mday = -1;
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alarm->time.tm_mon = -1;
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alarm->time.tm_year = -1;
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alarm->time.tm_wday = -1;
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alarm->time.tm_yday = -1;
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alarm->time.tm_isdst = -1;
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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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trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
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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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time64_t t_now, t_alm;
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enum { none, day, month, year } missing = none;
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unsigned int 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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rtc_add_offset(rtc, &alarm->time);
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return 0;
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}
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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 || alarm->time.tm_mday > 31) {
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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 ((unsigned int)alarm->time.tm_mon >= 12) {
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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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/* Can't proceed if alarm is still invalid after replacing
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* missing fields.
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*/
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err = rtc_valid_tm(&alarm->time);
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if (err)
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goto done;
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/* with luck, no rollover is needed */
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t_now = rtc_tm_to_time64(&now);
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t_alm = rtc_tm_to_time64(&alarm->time);
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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_time64_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 (!is_leap_year(alarm->time.tm_year + 1900) &&
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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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err = rtc_valid_tm(&alarm->time);
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done:
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if (err)
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dev_warn(&rtc->dev, "invalid alarm value: %ptR\n",
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&alarm->time);
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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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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->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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trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
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return err;
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}
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EXPORT_SYMBOL_GPL(rtc_read_alarm);
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static 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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time64_t 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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scheduled = rtc_tm_to_time64(&alarm->time);
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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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if (err)
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return err;
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now = rtc_tm_to_time64(&tm);
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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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rtc_subtract_offset(rtc, &alarm->time);
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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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trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err);
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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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if (!rtc->ops)
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return -ENODEV;
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else if (!rtc->ops->set_alarm)
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return -EINVAL;
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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 = rtc_valid_range(rtc, &alarm->time);
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if (err)
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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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rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
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rtc->aie_timer.period = 0;
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if (alarm->enabled)
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err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
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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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struct rtc_time now;
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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 = rtc_read_time(rtc, &now);
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if (err)
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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 = 0;
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/* Alarm has to be enabled & in the future for us to enqueue it */
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if (alarm->enabled && (rtc_tm_to_ktime(now) <
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rtc->aie_timer.node.expires)) {
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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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trace_rtc_timer_enqueue(&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_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;
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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 != 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)
|
|
err = -EINVAL;
|
|
else
|
|
err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
|
|
|
|
mutex_unlock(&rtc->ops_lock);
|
|
|
|
trace_rtc_alarm_irq_enable(enabled, err);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
|
|
|
|
int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
|
|
{
|
|
int err;
|
|
|
|
err = mutex_lock_interruptible(&rtc->ops_lock);
|
|
if (err)
|
|
return err;
|
|
|
|
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
|
|
if (enabled == 0 && rtc->uie_irq_active) {
|
|
mutex_unlock(&rtc->ops_lock);
|
|
return rtc_dev_update_irq_enable_emul(rtc, 0);
|
|
}
|
|
#endif
|
|
/* make sure we're changing state */
|
|
if (rtc->uie_rtctimer.enabled == enabled)
|
|
goto out;
|
|
|
|
if (rtc->uie_unsupported) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (enabled) {
|
|
struct rtc_time tm;
|
|
ktime_t now, onesec;
|
|
|
|
__rtc_read_time(rtc, &tm);
|
|
onesec = ktime_set(1, 0);
|
|
now = rtc_tm_to_ktime(tm);
|
|
rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
|
|
rtc->uie_rtctimer.period = ktime_set(1, 0);
|
|
err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
|
|
} else {
|
|
rtc_timer_remove(rtc, &rtc->uie_rtctimer);
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&rtc->ops_lock);
|
|
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
|
|
/*
|
|
* Enable emulation if the driver returned -EINVAL to signal that it has
|
|
* been configured without interrupts or they are not available at the
|
|
* moment.
|
|
*/
|
|
if (err == -EINVAL)
|
|
err = rtc_dev_update_irq_enable_emul(rtc, enabled);
|
|
#endif
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
|
|
|
|
/**
|
|
* rtc_handle_legacy_irq - AIE, UIE and PIE event hook
|
|
* @rtc: pointer to the rtc device
|
|
*
|
|
* This function is called when an AIE, UIE or PIE mode interrupt
|
|
* has occurred (or been emulated).
|
|
*
|
|
*/
|
|
void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* mark one irq of the appropriate mode */
|
|
spin_lock_irqsave(&rtc->irq_lock, flags);
|
|
rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF | mode);
|
|
spin_unlock_irqrestore(&rtc->irq_lock, flags);
|
|
|
|
wake_up_interruptible(&rtc->irq_queue);
|
|
kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
|
|
}
|
|
|
|
/**
|
|
* rtc_aie_update_irq - AIE mode rtctimer hook
|
|
* @rtc: pointer to the rtc_device
|
|
*
|
|
* This functions is called when the aie_timer expires.
|
|
*/
|
|
void rtc_aie_update_irq(struct rtc_device *rtc)
|
|
{
|
|
rtc_handle_legacy_irq(rtc, 1, RTC_AF);
|
|
}
|
|
|
|
/**
|
|
* rtc_uie_update_irq - UIE mode rtctimer hook
|
|
* @rtc: pointer to the rtc_device
|
|
*
|
|
* This functions is called when the uie_timer expires.
|
|
*/
|
|
void rtc_uie_update_irq(struct rtc_device *rtc)
|
|
{
|
|
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;
|
|
u64 count;
|
|
|
|
rtc = container_of(timer, struct rtc_device, pie_timer);
|
|
|
|
period = 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)
|
|
{
|
|
if (IS_ERR_OR_NULL(rtc))
|
|
return;
|
|
|
|
pm_stay_awake(rtc->dev.parent);
|
|
schedule_work(&rtc->irqwork);
|
|
}
|
|
EXPORT_SYMBOL_GPL(rtc_update_irq);
|
|
|
|
struct rtc_device *rtc_class_open(const char *name)
|
|
{
|
|
struct device *dev;
|
|
struct rtc_device *rtc = NULL;
|
|
|
|
dev = class_find_device_by_name(rtc_class, name);
|
|
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);
|
|
|
|
static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
|
|
{
|
|
/*
|
|
* We always cancel the timer here first, because otherwise
|
|
* we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
|
|
* when we manage to start the timer before the callback
|
|
* returns HRTIMER_RESTART.
|
|
*
|
|
* We cannot use hrtimer_cancel() here as a running callback
|
|
* could be blocked on rtc->irq_task_lock and hrtimer_cancel()
|
|
* would spin forever.
|
|
*/
|
|
if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
|
|
return -1;
|
|
|
|
if (enabled) {
|
|
ktime_t period = NSEC_PER_SEC / rtc->irq_freq;
|
|
|
|
hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
|
|
* @rtc: the rtc device
|
|
* @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.
|
|
*/
|
|
int rtc_irq_set_state(struct rtc_device *rtc, int enabled)
|
|
{
|
|
int err = 0;
|
|
|
|
while (rtc_update_hrtimer(rtc, enabled) < 0)
|
|
cpu_relax();
|
|
|
|
rtc->pie_enabled = enabled;
|
|
|
|
trace_rtc_irq_set_state(enabled, err);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
|
|
* @rtc: the rtc device
|
|
* @freq: positive frequency
|
|
* 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, int freq)
|
|
{
|
|
int err = 0;
|
|
|
|
if (freq <= 0 || freq > RTC_MAX_FREQ)
|
|
return -EINVAL;
|
|
|
|
rtc->irq_freq = freq;
|
|
while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0)
|
|
cpu_relax();
|
|
|
|
trace_rtc_irq_set_freq(freq, err);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
|
|
struct rtc_time tm;
|
|
ktime_t now;
|
|
|
|
timer->enabled = 1;
|
|
__rtc_read_time(rtc, &tm);
|
|
now = rtc_tm_to_ktime(tm);
|
|
|
|
/* Skip over expired timers */
|
|
while (next) {
|
|
if (next->expires >= now)
|
|
break;
|
|
next = timerqueue_iterate_next(next);
|
|
}
|
|
|
|
timerqueue_add(&rtc->timerqueue, &timer->node);
|
|
trace_rtc_timer_enqueue(timer);
|
|
if (!next || ktime_before(timer->node.expires, next->expires)) {
|
|
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) {
|
|
pm_stay_awake(rtc->dev.parent);
|
|
schedule_work(&rtc->irqwork);
|
|
} else if (err) {
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
trace_rtc_timer_dequeue(timer);
|
|
timer->enabled = 0;
|
|
return err;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void rtc_alarm_disable(struct rtc_device *rtc)
|
|
{
|
|
if (!rtc->ops || !rtc->ops->alarm_irq_enable)
|
|
return;
|
|
|
|
rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
|
|
trace_rtc_alarm_irq_enable(0, 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);
|
|
trace_rtc_timer_dequeue(timer);
|
|
timer->enabled = 0;
|
|
if (next == &timer->node) {
|
|
struct rtc_wkalrm alarm;
|
|
int err;
|
|
|
|
next = timerqueue_getnext(&rtc->timerqueue);
|
|
if (!next) {
|
|
rtc_alarm_disable(rtc);
|
|
return;
|
|
}
|
|
alarm.time = rtc_ktime_to_tm(next->expires);
|
|
alarm.enabled = 1;
|
|
err = __rtc_set_alarm(rtc, &alarm);
|
|
if (err == -ETIME) {
|
|
pm_stay_awake(rtc->dev.parent);
|
|
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 > now)
|
|
break;
|
|
|
|
/* expire timer */
|
|
timer = container_of(next, struct rtc_timer, node);
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
trace_rtc_timer_dequeue(timer);
|
|
timer->enabled = 0;
|
|
if (timer->func)
|
|
timer->func(timer->rtc);
|
|
|
|
trace_rtc_timer_fired(timer);
|
|
/* 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);
|
|
trace_rtc_timer_enqueue(timer);
|
|
}
|
|
}
|
|
|
|
/* Set next alarm */
|
|
if (next) {
|
|
struct rtc_wkalrm alarm;
|
|
int err;
|
|
int retry = 3;
|
|
|
|
alarm.time = rtc_ktime_to_tm(next->expires);
|
|
alarm.enabled = 1;
|
|
reprogram:
|
|
err = __rtc_set_alarm(rtc, &alarm);
|
|
if (err == -ETIME) {
|
|
goto again;
|
|
} else if (err) {
|
|
if (retry-- > 0)
|
|
goto reprogram;
|
|
|
|
timer = container_of(next, struct rtc_timer, node);
|
|
timerqueue_del(&rtc->timerqueue, &timer->node);
|
|
trace_rtc_timer_dequeue(timer);
|
|
timer->enabled = 0;
|
|
dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
|
|
goto again;
|
|
}
|
|
} else {
|
|
rtc_alarm_disable(rtc);
|
|
}
|
|
|
|
pm_relax(rtc->dev.parent);
|
|
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
|
|
* @rtc: pointer to the rtc_device
|
|
*
|
|
* Kernel interface to initializing an rtc_timer.
|
|
*/
|
|
void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
|
|
struct rtc_device *rtc)
|
|
{
|
|
timerqueue_init(&timer->node);
|
|
timer->enabled = 0;
|
|
timer->func = f;
|
|
timer->rtc = rtc;
|
|
}
|
|
|
|
/* 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
|
|
*/
|
|
void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
|
|
{
|
|
mutex_lock(&rtc->ops_lock);
|
|
if (timer->enabled)
|
|
rtc_timer_remove(rtc, timer);
|
|
mutex_unlock(&rtc->ops_lock);
|
|
}
|
|
|
|
/**
|
|
* rtc_read_offset - Read the amount of rtc offset in parts per billion
|
|
* @ rtc: rtc device to be used
|
|
* @ offset: the offset in parts per billion
|
|
*
|
|
* see below for details.
|
|
*
|
|
* Kernel interface to read rtc clock offset
|
|
* Returns 0 on success, or a negative number on error.
|
|
* If read_offset() is not implemented for the rtc, return -EINVAL
|
|
*/
|
|
int rtc_read_offset(struct rtc_device *rtc, long *offset)
|
|
{
|
|
int ret;
|
|
|
|
if (!rtc->ops)
|
|
return -ENODEV;
|
|
|
|
if (!rtc->ops->read_offset)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&rtc->ops_lock);
|
|
ret = rtc->ops->read_offset(rtc->dev.parent, offset);
|
|
mutex_unlock(&rtc->ops_lock);
|
|
|
|
trace_rtc_read_offset(*offset, ret);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* rtc_set_offset - Adjusts the duration of the average second
|
|
* @ rtc: rtc device to be used
|
|
* @ offset: the offset in parts per billion
|
|
*
|
|
* Some rtc's allow an adjustment to the average duration of a second
|
|
* to compensate for differences in the actual clock rate due to temperature,
|
|
* the crystal, capacitor, etc.
|
|
*
|
|
* The adjustment applied is as follows:
|
|
* t = t0 * (1 + offset * 1e-9)
|
|
* where t0 is the measured length of 1 RTC second with offset = 0
|
|
*
|
|
* Kernel interface to adjust an rtc clock offset.
|
|
* Return 0 on success, or a negative number on error.
|
|
* If the rtc offset is not setable (or not implemented), return -EINVAL
|
|
*/
|
|
int rtc_set_offset(struct rtc_device *rtc, long offset)
|
|
{
|
|
int ret;
|
|
|
|
if (!rtc->ops)
|
|
return -ENODEV;
|
|
|
|
if (!rtc->ops->set_offset)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&rtc->ops_lock);
|
|
ret = rtc->ops->set_offset(rtc->dev.parent, offset);
|
|
mutex_unlock(&rtc->ops_lock);
|
|
|
|
trace_rtc_set_offset(offset, ret);
|
|
return ret;
|
|
}
|