2022-04-10 15:56:45 -04:00

156 lines
10 KiB
C

/*
* 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_DEEPSLEEP_H_INCLUDED
#define _WATCH_DEEPSLEEP_H_INCLUDED
////< @file watch_deepsleep.h
#include "watch.h"
// These are declared in watch_rtc.c.
extern ext_irq_cb_t btn_alarm_callback;
extern ext_irq_cb_t a2_callback;
extern ext_irq_cb_t a4_callback;
/** @addtogroup deepsleep Sleep Control
* @brief This section covers functions related to the various sleep modes available to the watch,
* including Sleep, Deep Sleep, and BACKUP mode.
* @details These terms changed meaning a bit over the course of development; if you are coming
* to this documentation after having worked with an earlier version of the library,
* these definitions should clarify the terminology. Terms in all caps are modes of the
* SAM L22; terms in Title Case are specific implementations in this library.
* - ACTIVE mode is the mode the SAM L22 is in when both the main clock and the CPU are
* running. It is the most power-hungry mode. If you ever call delay_ms to wait a beat,
* the watch will remain in ACTIVE mode while taking that delay. In addition, whenever
* your `app_loop` function returns false, the device will remain in ACTIVE mode and
* call your `app_loop` function again.
* - STANDBY mode turns off the main clock and halts the CPU. Since the PWM driver is
* run from the main clock, it also stops the buzzer and any dimming of the LEDs.
* In this mode, the watch can wake from any interrupt source. Whenever your `app_loop`
* function returns true, the watch enters STANDBY mode until the next tick or other
* interrupt. This mode uses much less power than ACTIVE mode.
* - Sleep Mode is a special case of STANDBY mode. In this mode, the watch turns off
* almost all peripherals (including the external interrupt controller), and disables
* all pins except for the external wake pins. In this mode the watch can only wake
* from the RTC alarm interrupt or an external wake pin (A2, A4 or the alarm button),
* but the display remains on and your app's state is retained. You can enter this
* mode by calling `watch_enter_sleep_mode`. It consumes an order of magnitude less
* power than STANDBY mode.
* - Deep Sleep Mode is identical to sleep mode, but it also turns off the LCD to save
* a bit more power. You can enter this mode by calling `watch_enter_deep_sleep_mode`.
* - BACKUP mode is the lowest possible power mode on the SAM L22. It turns off all pins
* and peripherals except for the RTC. It also turns off the RAM, obliterating your
* application's state. The only way to wake from this mode is by setting an external
* wake interrupt on pin A2 or pin A4, and when you do wake it will be much like a
* wake from reset. You can enter this mode by calling `watch_enter_backup_mode`.
*/
/// @{
/** @brief Registers a callback on one of the RTC's external wake pins, which can wake the device
* from Sleep, Deep Sleep and BACKUP modes (but see warning re: BACKUP mode).
* @param pin Either pin BTN_ALARM, A2, or A4. These are the three external wake pins. If the pin
* is BTN_ALARM, this function also enables an internal pull down on that pin.
* @param callback The callback to be called if this pin triggers outside of BACKUP mode. If this is
* NULL, no callback will be called even in normal modes, but the interrupt will
* still be enabled so that it can wake the device.
* @param level The level you wish to scan for: true for rising, false for falling. Note that you
* cannot scan for both rising and falling edges like you can with the external interrupt
* pins; with the external wake interrupt, you can only get one or the other.
* @note When in ACTIVE, STANDBY and Sleep / Deep sleep modes, this will function much like a standard
* external interrupt situation: these pins will wake the device, and your callback will be
* called. However, if the device enters BACKUP mode and one of these pins wakes the device, your
* callback WILL NOT be called, as the device is basically waking from reset at that point.
* @warning As of the current SAM L22 silicon revision (rev B), the BTN_ALARM pin cannot wake the
* device from BACKUP mode. You can still use this function to register a BTN_ALARM interrupt
* in normal or deep sleep mode, but to wake from BACKUP, you will need to use pin A2 or A4.
*/
void watch_register_extwake_callback(uint8_t pin, ext_irq_cb_t callback, bool level);
/** @brief Unregisters the RTC interrupt on one of the EXTWAKE pins. This will prevent a value change on
* one of these pins from waking the device.
* @param pin Either pin BTN_ALARM, A2, or A4. If the pin is BTN_ALARM, this function DOES NOT disable
* the internal pull down on that pin.
*/
void watch_disable_extwake_interrupt(uint8_t pin);
/** @brief Stores data in one of the RTC's backup registers, which retain their data in BACKUP mode.
* @param data An unsigned 32 bit integer with the data you wish to store.
* @param reg A register from 0-7.
*/
void watch_store_backup_data(uint32_t data, uint8_t reg);
/** @brief Gets 32 bits of data from the RTC's BACKUP register.
* @param reg A register from 0-7.
* @return An unsigned 32 bit integer with the from the backup register.
*/
uint32_t watch_get_backup_data(uint8_t reg);
/** @brief enters Sleep Mode by disabling all pins and peripherals except the RTC and the LCD.
* @details This sleep mode is not the lowest power mode available, but it has the benefit of allowing you
* to display a message to the user while asleep. You can also set an alarm interrupt to wake at a
* configfurable interval (every minute, hour or day) to update the display. You can wake from this
* mode by pressing the ALARM button, if you registered an extwake callback on the ALARM button.
* Also note that when your app wakes from this sleep mode, your app_setup method will be called
* again, since this function will have disabled things you set up there.
*
* Note that to wake from either the ALARM button, the A2 interrupt or the A4 interrupt, you
* must first configure this by calling watch_register_extwake_callback.
*
* Power consumption depends on temperature, but as a rough estimate, this mode will consume:
* * 6.0 ~ 7.5µA while at normal room temperatures
* * 9.5µA while worn on a wrist (temperature ≈ 31° C)
*/
void watch_enter_sleep_mode(void);
/** @brief enters Deep Sleep Mode by disabling all pins and peripherals except the RTC.
* @details Short of BACKUP mode, this is the lowest power mode you can enter while retaining your
* application state (and the ability to wake with the alarm button). Just note that the display
* will be completely off, so you should document to the user of your application that they will
* need to press the alarm button to wake the device, or use a sensor board with support for
* an external wake pin.
*
* All notes from watch_enter_sleep_mode apply here, except for power consumption. You can estimate
* the power consumption of this mode to be on the order of 4µA at room temperature.
*/
void watch_enter_deep_sleep_mode(void);
/** @brief Enters the SAM L22's lowest-power mode, BACKUP.
* @details This function does some housekeeping before entering BACKUP mode. It first disables all pins
* and peripherals except for the RTC, and disables the tick interrupt (since that would wake
* us up from BACKUP mode). Once again, if you wish to wake from the A2 or the A4 interrupt,
* you must first configure this by calling watch_register_extwake_callback.
* @note If you have a callback set for an external wake interrupt, it will be called if triggered while
* in ACTIVE, STANDBY, Sleep and Deep Sleep modes, but it *will not be called* when waking from
* BACKUP mode. Waking from backup is effectively like waking from reset, except that your
* @ref app_wake_from_backup function will be called.
* @warning On current revisions of the SAM L22 silicon, the ALARM_BTN pin (PA02 RTC/IN2) cannot wake
* the device from deep sleep mode. There is an errata note (Reference: 15010) that says that
* due to a silicon bug, RTC/IN2 is not functional in BACKUP. As a result, you should not call
* this function unless you have a device on the nine-pin connector with an external interrupt
* on pin A2 or A4 (i.e. an accelerometer with an interrupt pin).
*/
void watch_enter_backup_mode(void);
/// @}
#endif