/* Copyright (c) 2012 Nordic Semiconductor. All Rights Reserved. * * The information contained herein is property of Nordic Semiconductor ASA. * Terms and conditions of usage are described in detail in NORDIC * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT. * * Licensees are granted free, non-transferable use of the information. NO * WARRANTY of ANY KIND is provided. This heading must NOT be removed from * the file. * */ /** @file * * @defgroup app_timer Application Timer * @{ * @ingroup app_common * * @brief Application timer functionality. * * @details This module enables the application to create multiple timer instances based on the RTC1 * peripheral. Checking for time-outs and invokation of user time-out handlers is performed * in the RTC1 interrupt handler. List handling is done using a software interrupt (SWI0). * Both interrupt handlers are running in APP_LOW priority level. * * @details When calling app_timer_start() or app_timer_stop(), the timer operation is just queued, * and the software interrupt is triggered. The actual timer start/stop operation is * executed by the SWI0 interrupt handler. Since the SWI0 interrupt is running in APP_LOW, * if the application code calling the timer function is running in APP_LOW or APP_HIGH, * the timer operation will not be performed until the application handler has returned. * This will be the case, for example, when stopping a timer from a time-out handler when not using * the scheduler. * * @details Use the USE_SCHEDULER parameter of the APP_TIMER_INIT() macro to select if the * @ref app_scheduler should be used or not. Even if the scheduler is * not used, app_timer.h will include app_scheduler.h, so when * compiling, app_scheduler.h must be available in one of the compiler include paths. */ #ifndef APP_TIMER_H__ #define APP_TIMER_H__ #include #include #include #include "app_error.h" #include "app_util.h" #include "compiler_abstraction.h" #define APP_TIMER_CLOCK_FREQ 32768 /**< Clock frequency of the RTC timer used to implement the app timer module. */ #define APP_TIMER_MIN_TIMEOUT_TICKS 5 /**< Minimum value of the timeout_ticks parameter of app_timer_start(). */ #define APP_TIMER_NODE_SIZE 32 /**< Size of app_timer.timer_node_t (used to allocate data). */ #define APP_TIMER_USER_OP_SIZE 24 /**< Size of app_timer.timer_user_op_t (only for use inside APP_TIMER_BUF_SIZE()). */ #define APP_TIMER_USER_SIZE 8 /**< Size of app_timer.timer_user_t (only for use inside APP_TIMER_BUF_SIZE()). */ #define APP_TIMER_INT_LEVELS 3 /**< Number of interrupt levels from where timer operations may be initiated (only for use inside APP_TIMER_BUF_SIZE()). */ /**@brief Compute number of bytes required to hold the application timer data structures. * * @param[in] OP_QUEUE_SIZE Size of queues holding timer operations that are pending execution. * Note that due to the queue implementation, this size must be one more * than the size that is actually needed. * * @return Required application timer buffer size (in bytes). */ #define APP_TIMER_BUF_SIZE(OP_QUEUE_SIZE) \ ( \ ( \ APP_TIMER_INT_LEVELS \ * \ (APP_TIMER_USER_SIZE + ((OP_QUEUE_SIZE) + 1) * APP_TIMER_USER_OP_SIZE) \ ) \ ) /**@brief Convert milliseconds to timer ticks. * * This macro uses 64-bit integer arithmetic, but as long as the macro parameters are * constants (i.e. defines), the computation will be done by the preprocessor. * * When using this macro, ensure that the * values provided as input result in an output value that is supported by the * @ref app_timer_start function. For example, when the ticks for 1 ms is needed, the * maximum possible value of PRESCALER must be 6, when @ref APP_TIMER_CLOCK_FREQ is 32768. * This will result in a ticks value as 5. Any higher value for PRESCALER will result in a * ticks value that is not supported by this module. * * @param[in] MS Milliseconds. * @param[in] PRESCALER Value of the RTC1 PRESCALER register (must be the same value that was * passed to APP_TIMER_INIT()). * * @return Number of timer ticks. */ #define APP_TIMER_TICKS(MS, PRESCALER)\ ((uint32_t)ROUNDED_DIV((MS) * (uint64_t)APP_TIMER_CLOCK_FREQ, ((PRESCALER) + 1) * 1000)) typedef struct app_timer_t { uint32_t data[CEIL_DIV(APP_TIMER_NODE_SIZE, sizeof(uint32_t))]; } app_timer_t; /**@brief Timer ID type. * Never declare a variable of this type, but use the macro @ref APP_TIMER_DEF instead.*/ typedef app_timer_t * app_timer_id_t; /** * @brief Create a timer identifier and statically allocate memory for the timer. * * @param timer_id Name of the timer identifier variable that will be used to control the timer. */ #define APP_TIMER_DEF(timer_id) \ static app_timer_t timer_id##_data = { {0} }; \ static const app_timer_id_t timer_id = &timer_id##_data /**@brief Application time-out handler type. */ typedef void (*app_timer_timeout_handler_t)(void * p_context); /**@brief Type of function for passing events from the timer module to the scheduler. */ typedef uint32_t (*app_timer_evt_schedule_func_t) (app_timer_timeout_handler_t timeout_handler, void * p_context); /**@brief Timer modes. */ typedef enum { APP_TIMER_MODE_SINGLE_SHOT, /**< The timer will expire only once. */ APP_TIMER_MODE_REPEATED /**< The timer will restart each time it expires. */ } app_timer_mode_t; /**@brief Initialize the application timer module. * * @details This macro handles dimensioning and allocation of the memory buffer required by the timer, * making sure that the buffer is correctly aligned. It will also connect the timer module * to the scheduler (if specified). * * @note This module assumes that the LFCLK is already running. If it is not, the module will * be non-functional, since the RTC will not run. If you do not use a SoftDevice, you * must start the LFCLK manually. See the rtc_example's lfclk_config() function * for an example of how to do this. If you use a SoftDevice, the LFCLK is started on * SoftDevice init. * * * @param[in] PRESCALER Value of the RTC1 PRESCALER register. This will decide the * timer tick rate. Set to 0 for no prescaling. * @param[in] OP_QUEUES_SIZE Size of queues holding timer operations that are pending execution. * @param[in] SCHEDULER_FUNC Pointer to scheduler event handler * * @note Since this macro allocates a buffer, it must only be called once (it is OK to call it * several times as long as it is from the same location, for example, to do a re-initialization). */ /*lint -emacro(506, APP_TIMER_INIT) */ /* Suppress "Constant value Boolean */ #define APP_TIMER_INIT(PRESCALER, OP_QUEUES_SIZE, SCHEDULER_FUNC) \ do \ { \ static uint32_t APP_TIMER_BUF[CEIL_DIV(APP_TIMER_BUF_SIZE((OP_QUEUES_SIZE) + 1), \ sizeof(uint32_t))]; \ uint32_t ERR_CODE = app_timer_init((PRESCALER), \ (OP_QUEUES_SIZE) + 1, \ APP_TIMER_BUF, \ SCHEDULER_FUNC); \ APP_ERROR_CHECK(ERR_CODE); \ } while (0) /**@brief Function for initializing the timer module. * * Normally, initialization should be done using the APP_TIMER_INIT() macro, because that macro will both * allocate the buffers needed by the timer module (including aligning the buffers correctly) * and take care of connecting the timer module to the scheduler (if specified). * * @param[in] prescaler Value of the RTC1 PRESCALER register. Set to 0 for no prescaling. * @param[in] op_queues_size Size of queues holding timer operations that are pending * execution. Note that due to the queue implementation, this size must * be one more than the size that is actually needed. * @param[in] p_buffer Pointer to memory buffer for internal use in the app_timer * module. The size of the buffer can be computed using the * APP_TIMER_BUF_SIZE() macro. The buffer must be aligned to a * 4 byte boundary. * @param[in] evt_schedule_func Function for passing time-out events to the scheduler. Point to * app_timer_evt_schedule() to connect to the scheduler. Set to NULL * to make the timer module call the time-out handler directly from * the timer interrupt handler. * * @retval NRF_SUCCESS If the module was initialized successfully. * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid (buffer not aligned to a 4 byte * boundary or NULL). */ uint32_t app_timer_init(uint32_t prescaler, uint8_t op_queues_size, void * p_buffer, app_timer_evt_schedule_func_t evt_schedule_func); /**@brief Function for creating a timer instance. * * @param[in] p_timer_id Pointer to timer identifier. * @param[in] mode Timer mode. * @param[in] timeout_handler Function to be executed when the timer expires. * * @retval NRF_SUCCESS If the timer was successfully created. * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or * the timer is running. * * @note This function does the timer allocation in the caller's context. It is also not protected * by a critical region. Therefore care must be taken not to call it from several interrupt * levels simultaneously. * @note The function can be called again on the timer instance and will re-initialize the instance if * the timer is not running. * @attention The FreeRTOS and RTX app_timer implementation does not allow app_timer_create to * be called on the previously initialized instance. */ uint32_t app_timer_create(app_timer_id_t const * p_timer_id, app_timer_mode_t mode, app_timer_timeout_handler_t timeout_handler); /**@brief Function for starting a timer. * * @param[in] timer_id Timer identifier. * @param[in] timeout_ticks Number of ticks (of RTC1, including prescaling) to time-out event * (minimum 5 ticks). * @param[in] p_context General purpose pointer. Will be passed to the time-out handler when * the timer expires. * * @retval NRF_SUCCESS If the timer was successfully started. * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or the timer * has not been created. * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. * * @note The minimum timeout_ticks value is 5. * @note For multiple active timers, time-outs occurring in close proximity to each other (in the * range of 1 to 3 ticks) will have a positive jitter of maximum 3 ticks. * @note When calling this method on a timer that is already running, the second start operation * is ignored. */ uint32_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context); /**@brief Function for stopping the specified timer. * * @param[in] timer_id Timer identifier. * * @retval NRF_SUCCESS If the timer was successfully stopped. * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or the timer * has not been created. * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. */ uint32_t app_timer_stop(app_timer_id_t timer_id); /**@brief Function for stopping all running timers. * * @retval NRF_SUCCESS If all timers were successfully stopped. * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized. * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. */ uint32_t app_timer_stop_all(void); /**@brief Function for returning the current value of the RTC1 counter. * * @param[out] p_ticks Current value of the RTC1 counter. * * @retval NRF_SUCCESS If the counter was successfully read. */ uint32_t app_timer_cnt_get(uint32_t * p_ticks); /**@brief Function for computing the difference between two RTC1 counter values. * * @param[in] ticks_to Value returned by app_timer_cnt_get(). * @param[in] ticks_from Value returned by app_timer_cnt_get(). * @param[out] p_ticks_diff Number of ticks from ticks_from to ticks_to. * * @retval NRF_SUCCESS If the counter difference was successfully computed. */ uint32_t app_timer_cnt_diff_compute(uint32_t ticks_to, uint32_t ticks_from, uint32_t * p_ticks_diff); #ifdef APP_TIMER_WITH_PROFILER /**@brief Function for getting the maximum observed operation queue utilization. * * Function for tuning the module and determining OP_QUEUE_SIZE value and thus module RAM usage. * * @return Maximum number of events in queue observed so far. */ uint8_t app_timer_op_queue_utilization_get(void); #endif #endif // APP_TIMER_H__ /** @} */