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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#include <linux/rtc.h>#include <linux/sched.h>#include <linux/module.h>#include <linux/log2.h>#include <linux/workqueue.h>
#define CREATE_TRACE_POINTS#include <trace/events/rtc.h>
static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
static void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm){ time64_t secs;
if (!rtc->offset_secs) return;
secs = rtc_tm_to_time64(tm);
/* * Since the reading time values from RTC device are always in the RTC * original valid range, but we need to skip the overlapped region * between expanded range and original range, which is no need to add * the offset. */ if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) || (rtc->start_secs < rtc->range_min && secs <= (rtc->start_secs + rtc->range_max - rtc->range_min))) return;
rtc_time64_to_tm(secs + rtc->offset_secs, tm);}
static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm){ time64_t secs;
if (!rtc->offset_secs) return;
secs = rtc_tm_to_time64(tm);
/* * If the setting time values are in the valid range of RTC hardware * device, then no need to subtract the offset when setting time to RTC * device. Otherwise we need to subtract the offset to make the time * values are valid for RTC hardware device. */ if (secs >= rtc->range_min && secs <= rtc->range_max) return;
rtc_time64_to_tm(secs - rtc->offset_secs, tm);}
static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm){ if (rtc->range_min != rtc->range_max) { time64_t time = rtc_tm_to_time64(tm); time64_t range_min = rtc->set_start_time ? rtc->start_secs : rtc->range_min; timeu64_t range_max = rtc->set_start_time ? (rtc->start_secs + rtc->range_max - rtc->range_min) : rtc->range_max;
if (time < range_min || time > range_max) return -ERANGE; }
return 0;}
static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm){ int err;
if (!rtc->ops) { err = -ENODEV; } else if (!rtc->ops->read_time) { err = -EINVAL; } else { memset(tm, 0, sizeof(struct rtc_time)); err = rtc->ops->read_time(rtc->dev.parent, tm); if (err < 0) { dev_dbg(&rtc->dev, "read_time: fail to read: %d\n", err); return err; }
rtc_add_offset(rtc, tm);
err = rtc_valid_tm(tm); if (err < 0) dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n"); } return err;}
int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm){ int err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
err = __rtc_read_time(rtc, tm); mutex_unlock(&rtc->ops_lock);
trace_rtc_read_time(rtc_tm_to_time64(tm), err); return err;}EXPORT_SYMBOL_GPL(rtc_read_time);
int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm){ int err, uie;
err = rtc_valid_tm(tm); if (err != 0) return err;
err = rtc_valid_range(rtc, tm); if (err) return err;
rtc_subtract_offset(rtc, tm);
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL uie = rtc->uie_rtctimer.enabled || rtc->uie_irq_active;#else uie = rtc->uie_rtctimer.enabled;#endif if (uie) { err = rtc_update_irq_enable(rtc, 0); if (err) return err; }
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
if (!rtc->ops) err = -ENODEV; else if (rtc->ops->set_time) err = rtc->ops->set_time(rtc->dev.parent, tm); else err = -EINVAL;
pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); /* A timer might have just expired */ schedule_work(&rtc->irqwork);
if (uie) { err = rtc_update_irq_enable(rtc, 1); if (err) return err; }
trace_rtc_set_time(rtc_tm_to_time64(tm), err); return err;}EXPORT_SYMBOL_GPL(rtc_set_time);
static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ int err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
if (!rtc->ops) { err = -ENODEV; } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->read_alarm) { err = -EINVAL; } else { alarm->enabled = 0; alarm->pending = 0; alarm->time.tm_sec = -1; alarm->time.tm_min = -1; alarm->time.tm_hour = -1; alarm->time.tm_mday = -1; alarm->time.tm_mon = -1; alarm->time.tm_year = -1; alarm->time.tm_wday = -1; alarm->time.tm_yday = -1; alarm->time.tm_isdst = -1; err = rtc->ops->read_alarm(rtc->dev.parent, alarm); }
mutex_unlock(&rtc->ops_lock);
trace_rtc_read_alarm(err?0:rtc_tm_to_time64(&alarm->time), err); return err;}
int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ int err; struct rtc_time before, now; int first_time = 1; time64_t t_now, t_alm; enum { none, day, month, year } missing = none; unsigned int days;
/* The lower level RTC driver may return -1 in some fields, * creating invalid alarm->time values, for reasons like: * * - The hardware may not be capable of filling them in; * many alarms match only on time-of-day fields, not * day/month/year calendar data. * * - Some hardware uses illegal values as "wildcard" match * values, which non-Linux firmware (like a BIOS) may try * to set up as e.g. "alarm 15 minutes after each hour". * Linux uses only oneshot alarms. * * When we see that here, we deal with it by using values from * a current RTC timestamp for any missing (-1) values. The * RTC driver prevents "periodic alarm" modes. * * But this can be racey, because some fields of the RTC timestamp * may have wrapped in the interval since we read the RTC alarm, * which would lead to us inserting inconsistent values in place * of the -1 fields. * * Reading the alarm and timestamp in the reverse sequence * would have the same race condition, and not solve the issue. * * So, we must first read the RTC timestamp, * then read the RTC alarm value, * and then read a second RTC timestamp. * * If any fields of the second timestamp have changed * when compared with the first timestamp, then we know * our timestamp may be inconsistent with that used by * the low-level rtc_read_alarm_internal() function. * * So, when the two timestamps disagree, we just loop and do * the process again to get a fully consistent set of values. * * This could all instead be done in the lower level driver, * but since more than one lower level RTC implementation needs it, * then it's probably best to do it here instead of there.. */
/* Get the "before" timestamp */ err = rtc_read_time(rtc, &before); if (err < 0) return err; do { if (!first_time) memcpy(&before, &now, sizeof(struct rtc_time)); first_time = 0;
/* get the RTC alarm values, which may be incomplete */ err = rtc_read_alarm_internal(rtc, alarm); if (err) return err;
/* full-function RTCs won't have such missing fields */ err = rtc_valid_tm(&alarm->time); if (!err) goto done;
/* get the "after" timestamp, to detect wrapped fields */ err = rtc_read_time(rtc, &now); if (err < 0) return err;
/* note that tm_sec is a "don't care" value here: */ } while (before.tm_min != now.tm_min || before.tm_hour != now.tm_hour || before.tm_mon != now.tm_mon || before.tm_year != now.tm_year);
/* Fill in the missing alarm fields using the timestamp; we * know there's at least one since alarm->time is invalid. */ if (alarm->time.tm_sec == -1) alarm->time.tm_sec = now.tm_sec; if (alarm->time.tm_min == -1) alarm->time.tm_min = now.tm_min; if (alarm->time.tm_hour == -1) alarm->time.tm_hour = now.tm_hour;
/* For simplicity, only support date rollover for now */ if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { alarm->time.tm_mday = now.tm_mday; missing = day; } if ((unsigned int)alarm->time.tm_mon >= 12) { alarm->time.tm_mon = now.tm_mon; if (missing == none) missing = month; } if (alarm->time.tm_year == -1) { alarm->time.tm_year = now.tm_year; if (missing == none) missing = year; }
/* Can't proceed if alarm is still invalid after replacing * missing fields. */ err = rtc_valid_tm(&alarm->time); if (err) goto done;
/* with luck, no rollover is needed */ t_now = rtc_tm_to_time64(&now); t_alm = rtc_tm_to_time64(&alarm->time); if (t_now < t_alm) goto done;
switch (missing) { /* 24 hour rollover ... if it's now 10am Monday, an alarm that * that will trigger at 5am will do so at 5am Tuesday, which * could also be in the next month or year. This is a common * case, especially for PCs. */ case day: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); t_alm += 24 * 60 * 60; rtc_time64_to_tm(t_alm, &alarm->time); break;
/* Month rollover ... if it's the 31th, an alarm on the 3rd will * be next month. An alarm matching on the 30th, 29th, or 28th * may end up in the month after that! Many newer PCs support * this type of alarm. */ case month: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); do { if (alarm->time.tm_mon < 11) { alarm->time.tm_mon++; } else { alarm->time.tm_mon = 0; alarm->time.tm_year++; } days = rtc_month_days(alarm->time.tm_mon, alarm->time.tm_year); } while (days < alarm->time.tm_mday); break;
/* Year rollover ... easy except for leap years! */ case year: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); do { alarm->time.tm_year++; } while (!is_leap_year(alarm->time.tm_year + 1900) && rtc_valid_tm(&alarm->time) != 0); break;
default: dev_warn(&rtc->dev, "alarm rollover not handled\n"); }
err = rtc_valid_tm(&alarm->time);
done: if (err && alarm->enabled) dev_warn(&rtc->dev, "invalid alarm value: %ptR\n", &alarm->time); else rtc_add_offset(rtc, &alarm->time);
return err;}
/** * rtc_read_next_alarm - read the next expiring alarm * @rtc: RTC device * @alarm: storage for the alarm information * * Read the next expiring alarm from the RTC timerqueue. This returns * the alarm that will actually fire next, which may be different from * rtc_read_alarm() if multiple timers are queued (e.g., alarmtimer * and wakealarm sysfs both active). * * Returns: 0 on success, -ENOENT if no alarm is pending, or other error. */int rtc_read_next_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ struct timerqueue_node *next; int err;
if (!rtc || !alarm) return -EINVAL;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
next = timerqueue_getnext(&rtc->timerqueue); if (!next) { err = -ENOENT; goto unlock; }
memset(alarm, 0, sizeof(struct rtc_wkalrm)); alarm->time = rtc_ktime_to_tm(next->expires); alarm->enabled = 1;
unlock: mutex_unlock(&rtc->ops_lock); return err;}EXPORT_SYMBOL_GPL(rtc_read_next_alarm);
int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ int err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (!rtc->ops) { err = -ENODEV; } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) { err = -EINVAL; } else { memset(alarm, 0, sizeof(struct rtc_wkalrm)); alarm->enabled = rtc->aie_timer.enabled; alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); } mutex_unlock(&rtc->ops_lock);
trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err); return err;}EXPORT_SYMBOL_GPL(rtc_read_alarm);
static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ struct rtc_time tm; time64_t now, scheduled; int err;
err = rtc_valid_tm(&alarm->time); if (err) return err;
scheduled = rtc_tm_to_time64(&alarm->time);
/* Make sure we're not setting alarms in the past */ err = __rtc_read_time(rtc, &tm); if (err) return err; now = rtc_tm_to_time64(&tm);
if (scheduled <= now) return -ETIME; /* * XXX - We just checked to make sure the alarm time is not * in the past, but there is still a race window where if * the is alarm set for the next second and the second ticks * over right here, before we set the alarm. */
rtc_subtract_offset(rtc, &alarm->time);
if (!rtc->ops) err = -ENODEV; else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) err = -EINVAL; else err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
/* * Check for potential race described above. If the waiting for next * second, and the second just ticked since the check above, either * * 1) It ticked after the alarm was set, and an alarm irq should be * generated. * * 2) It ticked before the alarm was set, and alarm irq most likely will * not be generated. * * While we cannot easily check for which of these two scenarios we * are in, we can return -ETIME to signal that the timer has already * expired, which is true in both cases. */ if (!err && (scheduled - now) <= 1) { err = __rtc_read_time(rtc, &tm); if (err) return err; now = rtc_tm_to_time64(&tm); if (scheduled <= now) return -ETIME; }
trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err); return err;}
int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ ktime_t alarm_time; int err;
if (!rtc->ops) return -ENODEV; else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) return -EINVAL;
err = rtc_valid_tm(&alarm->time); if (err != 0) return err;
err = rtc_valid_range(rtc, &alarm->time); if (err) return err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (rtc->aie_timer.enabled) rtc_timer_remove(rtc, &rtc->aie_timer);
alarm_time = rtc_tm_to_ktime(alarm->time); /* * Round down so we never miss a deadline, checking for past deadline is * done in __rtc_set_alarm */ if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features)) alarm_time = ktime_sub_ns(alarm_time, (u64)alarm->time.tm_sec * NSEC_PER_SEC);
rtc->aie_timer.node.expires = alarm_time; rtc->aie_timer.period = 0; if (alarm->enabled) err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
mutex_unlock(&rtc->ops_lock);
return err;}EXPORT_SYMBOL_GPL(rtc_set_alarm);
/* Called once per device from rtc_device_register */int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm){ int err; struct rtc_time now;
err = rtc_valid_tm(&alarm->time); if (err != 0) return err;
err = rtc_read_time(rtc, &now); if (err) return err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); rtc->aie_timer.period = 0;
/* Alarm has to be enabled & in the future for us to enqueue it */ if (alarm->enabled && (rtc_tm_to_ktime(now) < rtc->aie_timer.node.expires)) { rtc->aie_timer.enabled = 1; timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); trace_rtc_timer_enqueue(&rtc->aie_timer); } mutex_unlock(&rtc->ops_lock); return err;}EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled){ int err;
err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err;
if (rtc->aie_timer.enabled != enabled) { if (enabled) err = rtc_timer_enqueue(rtc, &rtc->aie_timer); else rtc_timer_remove(rtc, &rtc->aie_timer); }
if (err) /* nothing */; else if (!rtc->ops) err = -ENODEV; else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !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 (!test_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features) || !test_bit(RTC_FEATURE_ALARM, rtc->features)) { mutex_unlock(&rtc->ops_lock);#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL return rtc_dev_update_irq_enable_emul(rtc, enabled);#else return -EINVAL;#endif }
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); if (!err && rtc->ops && rtc->ops->alarm_irq_enable) err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1); if (err) goto out; } 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 occurrence of the event * @mode: type of the event, RTC_AF, RTC_UF or 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; int err;
err = __rtc_read_time(rtc, &tm); if (err) return err;
timer->enabled = 1; 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;
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; int err;
struct rtc_device *rtc = container_of(work, struct rtc_device, irqwork);
mutex_lock(&rtc->ops_lock);again: err = __rtc_read_time(rtc, &tm); if (err) { mutex_unlock(&rtc->ops_lock); return; } 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;}