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Diffstat (limited to 'watch-library/shared/watch/watch_rtc.h')
| -rw-r--r-- | watch-library/shared/watch/watch_rtc.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/watch-library/shared/watch/watch_rtc.h b/watch-library/shared/watch/watch_rtc.h new file mode 100644 index 00000000..6dac63f5 --- /dev/null +++ b/watch-library/shared/watch/watch_rtc.h @@ -0,0 +1,164 @@ +/* + * MIT License + * + * Copyright (c) 2020 Joey Castillo + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#ifndef _WATCH_RTC_H_INCLUDED +#define _WATCH_RTC_H_INCLUDED +////< @file watch_rtc.h + +#include "watch.h" +#include "hpl_calendar.h" + +/** @addtogroup rtc Real-Time Clock + * @brief This section covers functions related to the SAM L22's real-time clock peripheral, including + * date, time and alarm functions. + * @details The real-time clock is the only peripheral that main.c enables for you. It is the cornerstone + * of low power operation on the watch, and it is required for several key functions that we + * assume will be available, namely the wake from BACKUP mode and the callback on the ALARM button. + * It is also required for the operation of the 1 Hz tick interrupt, which you will most likely use + * to wake from STANDBY mode. + */ +/// @{ + +#define WATCH_RTC_REFERENCE_YEAR (2020) + +typedef union { + struct { + uint32_t second : 6; // 0-59 + uint32_t minute : 6; // 0-59 + uint32_t hour : 5; // 0-23 + uint32_t day : 5; // 1-31 + uint32_t month : 4; // 1-12 + uint32_t year : 6; // 0-63 (representing 2020-2083) + } unit; + uint32_t reg; // the bit-packed value as expected by the RTC peripheral's CLOCK register. +} watch_date_time; + +typedef enum watch_rtc_alarm_match { + ALARM_MATCH_DISABLED = 0, + ALARM_MATCH_SS, + ALARM_MATCH_MMSS, + ALARM_MATCH_HHMMSS, +} watch_rtc_alarm_match; + +/** @brief Called by main.c to check if the RTC is enabled. + * You may call this function, but outside of app_init, it should always return true. + */ +bool _watch_rtc_is_enabled(void); + +/** @brief Sets the date and time. + * @param date_time The date and time you wish to set, with a year value from 0-63 representing 2020-2083. + * @note The SAM L22 stores the year as six bits representing a value from 0 to 63. It treats this as a year + * offset from a reference year, which must be a leap year. Since 2020 was a leap year, and it allows + * useful dates through 2083, it is assumed that watch apps will use 2020 as the reference year; thus + * 1 means 2021, 2 means 2022, etc. **You will be responsible for handling this offset in your code**, + * if the calendar year is needed for timestamp calculation logic or display purposes. + */ +void watch_rtc_set_date_time(watch_date_time date_time); + +/** @brief Returns the date and time. + * @return A watch_date_time with the current date and time, with a year value from 0-63 representing 2020-2083. + * @see watch_rtc_set_date_time for notes about how the year is stored. + */ +watch_date_time watch_rtc_get_date_time(void); + +/** @brief Registers an alarm callback that will be called when the RTC time matches the target time, as masked + * by the provided mask. + * @param callback The function you wish to have called when the alarm fires. If this value is NULL, the alarm + * interrupt will still be enabled, but no callback function will be called. + * @param alarm_time The time that you wish to match. The date is currently ignored. + * @param mask One of the values in watch_rtc_alarm_match indicating which values to check. + * @details The alarm interrupt is a versatile tool for scheduling events in the future, especially since it can + * wake the device from all sleep modes. The key to its versatility is the mask parameter. + * Suppose we set an alarm for midnight, 00:00:00. + * * if mask is ALARM_MATCH_SS, the alarm will fire every minute when the clock ticks to seconds == 0. + * * with ALARM_MATCH_MMSS, the alarm will once an hour, at the top of each hour. + * * with ALARM_MATCH_HHMMSS, the alarm will fire at midnight every day. + * In theory the SAM L22's alarm function can match on days, months and even years, but I have not had + * success with this yet; as such, I am omitting these options for now. + */ +void watch_rtc_register_alarm_callback(ext_irq_cb_t callback, watch_date_time alarm_time, watch_rtc_alarm_match mask); + +/** @brief Disables the alarm callback. + */ +void watch_rtc_disable_alarm_callback(void); + +/** @brief Registers a "tick" callback that will be called once per second. + * @param callback The function you wish to have called when the clock ticks. If you pass in NULL, the tick + * interrupt will still be enabled, but no callback function will be called. + * @note this is equivalent to calling watch_rtc_register_periodic_callback with a frequency of 1. It can be + * disabled with either watch_rtc_disable_tick_callback() or watch_rtc_disable_periodic_callback(1), + * and will also be disabled when watch_rtc_disable_all_periodic_callbacks is called. + */ +void watch_rtc_register_tick_callback(ext_irq_cb_t callback); + +/** @brief Disables the tick callback for the given period. + */ +void watch_rtc_disable_tick_callback(void); + +/** @brief Registers a callback that will be called at a configurable period. + * @param callback The function you wish to have called at the specified period. If you pass in NULL, the periodic + * interrupt will still be enabled, but no callback function will be called. + * @param frequency The frequency of the tick in Hz. **Must be a power of 2**, from 1 to 128 inclusive. + * @note A 1 Hz tick (@see watch_rtc_register_tick_callback) is suitable for most applications, in that it gives you a + * chance to update the display once a second — an ideal update rate for a watch! If however you are displaying + * a value (such as an accelerometer output) that updates more frequently than once per second, you may want to + * tick at 16 or 32 Hz to update the screen more quickly. Just remember that the more frequent the tick, the more + * power your app will consume. Ideally you should enable the fast tick only when the user requires it (i.e. in + * response to an input event), and move back to the slow tick after some time. + * + * Also note that the RTC peripheral does not have sub-second resolution, so even if you set a 2 or 4 Hz interval, + * the system will not have any way of telling you where you are within a given second; watch_rtc_get_date_time + * will return the exact same timestamp until the second ticks over. + */ +void watch_rtc_register_periodic_callback(ext_irq_cb_t callback, uint8_t frequency); + +/** @brief Disables the tick callback for the given period. + * @param frequency The frequency of the tick you wish to disable, in Hz. **Must be a power of 2**, from 1 to 128. + */ +void watch_rtc_disable_periodic_callback(uint8_t frequency); + +/** @brief Disables all periodic callbacks, including the once-per-second tick callback. + */ +void watch_rtc_disable_all_periodic_callbacks(void); + +/** @brief Sets the system date and time. + * @param date_time A struct representing the date and time you wish to set. + */ +__attribute__((deprecated("Use watch_rtc_set_date_time function instead"))) +void watch_set_date_time(struct calendar_date_time date_time); + +/** @brief Returns the system date and time in the provided struct. + * @param date_time A pointer to a calendar_date_time struct. It will have with the correct date and time on return. + */ +__attribute__((deprecated("Use the watch_rtc_get_date_time function instead"))) +void watch_get_date_time(struct calendar_date_time *date_time); + +/** @brief Registers a "tick" callback that will be called once per second. + * @param callback The function you wish to have called when the clock ticks. If you pass in NULL, the tick + * interrupt will still be enabled, but no callback function will be called. + */ +__attribute__((deprecated("Use the watch_rtc_register_tick_callback function instead"))) +void watch_register_tick_callback(ext_irq_cb_t callback); + +/// @} +#endif |