// SPDX-License-Identifier: GPL-2.0 /* * RTC subsystem, interface functions * * Copyright (C) 2005 Tower Technologies * Author: Alessandro Zummo <[email protected]> * * based on arch/arm/common/rtctime.c */ #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) { … } static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm) { … } static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm) { … } static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) { … } int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) { … } EXPORT_SYMBOL_GPL(…); int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) { … } EXPORT_SYMBOL_GPL(…); static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } EXPORT_SYMBOL_GPL(…); static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } EXPORT_SYMBOL_GPL(…); /* Called once per device from rtc_device_register */ int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { … } EXPORT_SYMBOL_GPL(…); int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) { … } EXPORT_SYMBOL_GPL(…); int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } /** * 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_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_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) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); struct rtc_device *rtc_class_open(const char *name) { … } EXPORT_SYMBOL_GPL(…); void rtc_class_close(struct rtc_device *rtc) { … } EXPORT_SYMBOL_GPL(…); static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) { … } /** * 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) { … } /** * 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) { … } /** * 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) { … } static void rtc_alarm_disable(struct rtc_device *rtc) { … } /** * 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) { … } /** * 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) { … } /* 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) { … } /* 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) { … } /* 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) { … } /** * 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) { … } /** * 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) { … }
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