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1072 lines
26 KiB
1072 lines
26 KiB
// 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 <[email protected]> |
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* |
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* based on arch/arm/common/rtctime.c |
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*/ |
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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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|
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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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|
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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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|
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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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/* |
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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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|
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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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|
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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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/* |
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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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|
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rtc_time64_to_tm(secs - rtc->offset_secs, tm); |
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} |
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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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timeu64_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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|
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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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|
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rtc_add_offset(rtc, tm); |
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|
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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, uie; |
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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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|
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#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
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uie = rtc->uie_rtctimer.enabled || rtc->uie_irq_active; |
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#else |
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uie = rtc->uie_rtctimer.enabled; |
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#endif |
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if (uie) { |
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err = rtc_update_irq_enable(rtc, 0); |
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if (err) |
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return err; |
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} |
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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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if (uie) { |
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err = rtc_update_irq_enable(rtc, 1); |
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if (err) |
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return err; |
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} |
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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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|
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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 (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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err = rtc_valid_tm(&alarm->time); |
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|
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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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|
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return err; |
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} |
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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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|
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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 (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !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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|
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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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|
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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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|
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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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|
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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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|
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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 (!test_bit(RTC_FEATURE_ALARM, rtc->features)) |
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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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|
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if (!rtc->ops) |
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return -ENODEV; |
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else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) |
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return -EINVAL; |
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|
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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 (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !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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trace_rtc_alarm_irq_enable(enabled, err); |
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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; |
|
|
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err = mutex_lock_interruptible(&rtc->ops_lock); |
|
if (err) |
|
return err; |
|
|
|
#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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#endif |
|
/* make sure we're changing state */ |
|
if (rtc->uie_rtctimer.enabled == enabled) |
|
goto out; |
|
|
|
if (rtc->uie_unsupported || !test_bit(RTC_FEATURE_ALARM, rtc->features)) { |
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mutex_unlock(&rtc->ops_lock); |
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#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
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return rtc_dev_update_irq_enable_emul(rtc, enabled); |
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#else |
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return -EINVAL; |
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#endif |
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} |
|
|
|
if (enabled) { |
|
struct rtc_time tm; |
|
ktime_t now, onesec; |
|
|
|
err = __rtc_read_time(rtc, &tm); |
|
if (err) |
|
goto out; |
|
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); |
|
|
|
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 |
|
* @num: number of occurence of the event |
|
* @mode: type of the event, RTC_AF, RTC_UF of RTC_PF |
|
* |
|
* 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 || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !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 |
|
* @work: work item |
|
* |
|
* 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; |
|
}
|
|
|