RTC auf true
Diff: hal/ticker_api.h
- Revision:
- 0:38ceb79fef03
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hal/ticker_api.h Wed Nov 28 15:10:15 2018 +0000 @@ -0,0 +1,230 @@ + +/** \addtogroup hal */ +/** @{*/ +/* mbed Microcontroller Library + * Copyright (c) 2015 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBED_TICKER_API_H +#define MBED_TICKER_API_H + +#include <stdint.h> +#include <stdbool.h> +#include "device.h" + +/** + * Legacy format representing a timestamp in us. + * Given it is modeled as a 32 bit integer, this type can represent timestamp + * up to 4294 seconds (71 minutes). + * Prefer using us_timestamp_t which store timestamp as 64 bits integer. + */ +typedef uint32_t timestamp_t; + +/** + * A us timestamp stored in a 64 bit integer. + * Can store timestamp up to 584810 years. + */ +typedef uint64_t us_timestamp_t; + +/** Ticker's event structure + */ +typedef struct ticker_event_s { + us_timestamp_t timestamp; /**< Event's timestamp */ + uint32_t id; /**< TimerEvent object */ + struct ticker_event_s *next; /**< Next event in the queue */ +} ticker_event_t; + +typedef void (*ticker_event_handler)(uint32_t id); + +/** Information about the ticker implementation + */ +typedef struct { + uint32_t frequency; /**< Frequency in Hz this ticker runs at */ + uint32_t bits; /**< Number of bits this ticker supports */ +} ticker_info_t; + + +/** Ticker's interface structure - required API for a ticker + */ +typedef struct { + void (*init)(void); /**< Init function */ + uint32_t (*read)(void); /**< Read function */ + void (*disable_interrupt)(void); /**< Disable interrupt function */ + void (*clear_interrupt)(void); /**< Clear interrupt function */ + void (*set_interrupt)(timestamp_t timestamp); /**< Set interrupt function */ + void (*fire_interrupt)(void); /**< Fire interrupt right-away */ + void (*free)(void); /**< Disable function */ + const ticker_info_t *(*get_info)(void); /**< Return info about this ticker's implementation */ +} ticker_interface_t; + +/** Ticker's event queue structure + */ +typedef struct { + ticker_event_handler event_handler; /**< Event handler */ + ticker_event_t *head; /**< A pointer to head */ + uint32_t frequency; /**< Frequency of the timer in Hz */ + uint32_t bitmask; /**< Mask to be applied to time values read */ + uint32_t max_delta; /**< Largest delta in ticks that can be used when scheduling */ + uint64_t max_delta_us; /**< Largest delta in us that can be used when scheduling */ + uint32_t tick_last_read; /**< Last tick read */ + uint64_t tick_remainder; /**< Ticks that have not been added to base_time */ + us_timestamp_t present_time; /**< Store the timestamp used for present time */ + bool initialized; /**< Indicate if the instance is initialized */ + bool dispatching; /**< The function ticker_irq_handler is dispatching */ + bool suspended; /**< Indicate if the instance is suspended */ + uint8_t frequency_shifts; /**< If frequency is a value of 2^n, this is n, otherwise 0 */ +} ticker_event_queue_t; + +/** Ticker's data structure + */ +typedef struct { + const ticker_interface_t *interface; /**< Ticker's interface */ + ticker_event_queue_t *queue; /**< Ticker's event queue */ +} ticker_data_t; + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \defgroup hal_ticker Ticker HAL functions + * @{ + */ + +/** Initialize a ticker and set the event handler + * + * @param ticker The ticker object. + * @param handler A handler to be set + */ +void ticker_set_handler(const ticker_data_t *const ticker, ticker_event_handler handler); + +/** IRQ handler that goes through the events to trigger overdue events. + * + * @param ticker The ticker object. + */ +void ticker_irq_handler(const ticker_data_t *const ticker); + +/** Remove an event from the queue + * + * @param ticker The ticker object. + * @param obj The event object to be removed from the queue + */ +void ticker_remove_event(const ticker_data_t *const ticker, ticker_event_t *obj); + +/** Insert an event to the queue + * + * The event will be executed in timestamp - ticker_read(). + * + * @warning This function does not consider timestamp in the past. If an event + * is inserted with a timestamp less than the current timestamp then the event + * will be executed in timestamp - ticker_read() us. + * The internal counter wrap very quickly it is hard to decide weither an + * event is in the past or in 1 hour. + * + * @note prefer the use of ticker_insert_event_us which allows registration of + * absolute timestamp. + * + * @param ticker The ticker object. + * @param obj The event object to be inserted to the queue + * @param timestamp The event's timestamp + * @param id The event object + */ +void ticker_insert_event(const ticker_data_t *const ticker, ticker_event_t *obj, timestamp_t timestamp, uint32_t id); + +/** Insert an event to the queue + * + * The event will be executed in timestamp - ticker_read_us() us. + * + * @note If an event is inserted with a timestamp less than the current + * timestamp then the event will be scheduled immediately resulting in + * an instant call to event handler. + * + * @param ticker The ticker object. + * @param obj The event object to be inserted to the queue + * @param timestamp The event's timestamp + * @param id The event object + */ +void ticker_insert_event_us(const ticker_data_t *const ticker, ticker_event_t *obj, us_timestamp_t timestamp, uint32_t id); + +/** Read the current (relative) ticker's timestamp + * + * @warning Return a relative timestamp because the counter wrap every 4294 + * seconds. + * + * @param ticker The ticker object. + * @return The current timestamp + */ +timestamp_t ticker_read(const ticker_data_t *const ticker); + +/** Read the current (absolute) ticker's timestamp + * + * @warning Return an absolute timestamp counting from the initialization of the + * ticker. + * + * @param ticker The ticker object. + * @return The current timestamp + */ +us_timestamp_t ticker_read_us(const ticker_data_t *const ticker); + +/** Read the next event's timestamp + * + * @param ticker The ticker object. + * @param timestamp The timestamp object. + * @return 1 if timestamp is pending event, 0 if there's no event pending + */ +int ticker_get_next_timestamp(const ticker_data_t *const ticker, timestamp_t *timestamp); + +/** Suspend this ticker + * + * When suspended reads will always return the same time and no + * events will be dispatched. When suspended the common layer + * will only ever call the interface function clear_interrupt() + * and that is only if ticker_irq_handler is called. + * + * + * @param ticker The ticker object. + */ +void ticker_suspend(const ticker_data_t *const ticker); + +/** Resume this ticker + * + * When resumed the ticker will ignore any time that has passed + * and continue counting up where it left off. + * + * @param ticker The ticker object. + */ +void ticker_resume(const ticker_data_t *const ticker); + +/* Private functions + * + * @cond PRIVATE + * + */ + +int _ticker_match_interval_passed(timestamp_t prev_tick, timestamp_t cur_tick, timestamp_t match_tick); + +/* + * @endcond PRIVATE + * + */ + +/**@}*/ + +#ifdef __cplusplus +} +#endif + +#endif + +/** @}*/