mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/Lib/app_common/app_timer.c
- Committer:
- mbed_official
- Date:
- 2014-08-29
- Revision:
- 304:89b9c3a9a045
File content as of revision 304:89b9c3a9a045:
/* 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. * */ #include "app_timer.h" #include <stdlib.h> #include "nrf51.h" #include "nrf51_bitfields.h" #include "nrf_soc.h" #include "app_error.h" #include "nrf_delay.h" #include "app_util.h" #include "app_util_platform.h" #define RTC1_IRQ_PRI APP_IRQ_PRIORITY_LOW /**< Priority of the RTC1 interrupt (used for checking for timeouts and executing timeout handlers). */ #define SWI0_IRQ_PRI APP_IRQ_PRIORITY_LOW /**< Priority of the SWI0 interrupt (used for updating the timer list). */ // The current design assumes that both interrupt handlers run at the same interrupt level. // If this is to be changed, protection must be added to prevent them from interrupting each other // (e.g. by using guard/trigger flags). STATIC_ASSERT(RTC1_IRQ_PRI == SWI0_IRQ_PRI); #define APP_HIGH_USER_ID 0 /**< User Id for the Application High "user". */ #define APP_LOW_USER_ID 1 /**< User Id for the Application Low "user". */ #define THREAD_MODE_USER_ID 2 /**< User Id for the Thread Mode "user". */ #define RTC_COMPARE_OFFSET_MIN 3 /**< Minimum offset between the current RTC counter value and the Capture Compare register. Although the nRF51 Series User Specification recommends this value to be 2, we use 3 to be safer.*/ #define MAX_RTC_TASKS_DELAY 47 /**< Maximum delay until an RTC task is executed. */ /**@brief Timer allocation state type. */ typedef enum { STATE_FREE, /**< The timer node is available. */ STATE_ALLOCATED /**< The timer node has been allocated. */ } timer_alloc_state_t; /**@brief Timer node type. The nodes will be used form a linked list of running timers. */ typedef struct { timer_alloc_state_t state; /**< Timer allocation state. */ app_timer_mode_t mode; /**< Timer mode. */ uint32_t ticks_to_expire; /**< Number of ticks from previous timer interrupt to timer expiry. */ uint32_t ticks_at_start; /**< Current RTC counter value when the timer was started. */ uint32_t ticks_first_interval; /**< Number of ticks in the first timer interval. */ uint32_t ticks_periodic_interval; /**< Timer period (for repeating timers). */ bool is_running; /**< True if timer is running, False otherwise. */ app_timer_timeout_handler_t p_timeout_handler; /**< Pointer to function to be executed when the timer expires. */ void * p_context; /**< General purpose pointer. Will be passed to the timeout handler when the timer expires. */ app_timer_id_t next; /**< Id of next timer in list of running timers. */ } timer_node_t; STATIC_ASSERT(sizeof(timer_node_t) <= APP_TIMER_NODE_SIZE); STATIC_ASSERT(sizeof(timer_node_t) % 4 == 0); /**@brief Set of available timer operation types. */ typedef enum { TIMER_USER_OP_TYPE_NONE, /**< Invalid timer operation type. */ TIMER_USER_OP_TYPE_START, /**< Timer operation type Start. */ TIMER_USER_OP_TYPE_STOP, /**< Timer operation type Stop. */ TIMER_USER_OP_TYPE_STOP_ALL /**< Timer operation type Stop All. */ } timer_user_op_type_t; /**@brief Structure describing a timer start operation. */ typedef struct { uint32_t ticks_at_start; /**< Current RTC counter value when the timer was started. */ uint32_t ticks_first_interval; /**< Number of ticks in the first timer interval. */ uint32_t ticks_periodic_interval; /**< Timer period (for repeating timers). */ void * p_context; /**< General purpose pointer. Will be passed to the timeout handler when the timer expires. */ } timer_user_op_start_t; /**@brief Structure describing a timer operation. */ typedef struct { timer_user_op_type_t op_type; /**< Timer operation type. */ app_timer_id_t timer_id; /**< Id of timer on which the operation is to be performed. */ union { timer_user_op_start_t start; /**< Structure describing a timer start operation. */ } params; } timer_user_op_t; STATIC_ASSERT(sizeof(timer_user_op_t) <= APP_TIMER_USER_OP_SIZE); STATIC_ASSERT(sizeof(timer_user_op_t) % 4 == 0); /**@brief Structure describing a timer user. * * @details For each user of the timer module, there will be a timer operations queue. This queue * will hold timer operations issued by this user until the timer interrupt handler * processes these operations. For the current implementation, there will be one user for * each interrupt level available to the application (APP_HIGH, APP_LOW and THREAD_MODE), * but the module can easily be modified to e.g. have one queue per process when using an * RTOS. The purpose of the queues is to be able to have a completely lockless timer * implementation. */ typedef struct { uint8_t first; /**< Index of first entry to have been inserted in the queue (i.e. the next entry to be executed). */ uint8_t last; /**< Index of last entry to have been inserted in the queue. */ uint8_t user_op_queue_size; /**< Queue size. */ timer_user_op_t * p_user_op_queue; /**< Queue buffer. */ } timer_user_t; STATIC_ASSERT(sizeof(timer_user_t) == APP_TIMER_USER_SIZE); STATIC_ASSERT(sizeof(timer_user_t) % 4 == 0); /**@brief User id type. * * @details In the current implementation, this will automatically be generated from the current * interrupt level. */ typedef uint32_t timer_user_id_t; #define CONTEXT_QUEUE_SIZE_MAX (2) /**< Timer internal elapsed ticks queue size. */ static uint8_t m_node_array_size; /**< Size of timer node array. */ static timer_node_t * mp_nodes = NULL; /**< Array of timer nodes. */ static uint8_t m_user_array_size; /**< Size of timer user array. */ static timer_user_t * mp_users; /**< Array of timer users. */ static app_timer_id_t m_timer_id_head; /**< First timer in list of running timers. */ static uint32_t m_ticks_latest; /**< Last known RTC counter value. */ static uint32_t m_ticks_elapsed[CONTEXT_QUEUE_SIZE_MAX]; /**< Timer internal elapsed ticks queue. */ static uint8_t m_ticks_elapsed_q_read_ind; /**< Timer internal elapsed ticks queue read index. */ static uint8_t m_ticks_elapsed_q_write_ind; /**< Timer internal elapsed ticks queue write index. */ static app_timer_evt_schedule_func_t m_evt_schedule_func; /**< Pointer to function for propagating timeout events to the scheduler. */ static bool m_rtc1_running; /**< Boolean indicating if RTC1 is running. */ static volatile uint64_t overflowBits; /**< The upper 40 bits of the 64-bit value returned by cnt_get() */ /**@brief Function for initializing the RTC1 counter. * * @param[in] prescaler Value of the RTC1 PRESCALER register. Set to 0 for no prescaling. */ static void rtc1_init(uint32_t prescaler) { NRF_RTC1->PRESCALER = prescaler; NVIC_SetPriority(RTC1_IRQn, RTC1_IRQ_PRI); } /**@brief Function for starting the RTC1 timer. */ static void rtc1_start(void) { if (m_rtc1_running) { return; } NRF_RTC1->EVTENSET = RTC_EVTEN_COMPARE0_Msk; NRF_RTC1->INTENSET = RTC_INTENSET_COMPARE0_Msk | RTC_INTENSET_OVRFLW_Msk; NVIC_ClearPendingIRQ(RTC1_IRQn); NVIC_EnableIRQ(RTC1_IRQn); NRF_RTC1->TASKS_START = 1; nrf_delay_us(MAX_RTC_TASKS_DELAY); m_rtc1_running = true; } /**@brief Function for stopping the RTC1 timer. */ static void rtc1_stop(void) { if (!m_rtc1_running) { return; } NVIC_DisableIRQ(RTC1_IRQn); NRF_RTC1->EVTENCLR = RTC_EVTEN_COMPARE0_Msk; NRF_RTC1->INTENCLR = RTC_INTENSET_COMPARE0_Msk | RTC_INTENSET_OVRFLW_Msk; NRF_RTC1->TASKS_STOP = 1; nrf_delay_us(MAX_RTC_TASKS_DELAY); NRF_RTC1->TASKS_CLEAR = 1; m_ticks_latest = 0; nrf_delay_us(MAX_RTC_TASKS_DELAY); m_rtc1_running = false; } /**@brief Function for returning the current value of the RTC1 counter. * * @return Current value of the RTC1 counter. */ static __INLINE uint32_t rtc1_counter_get(void) { return NRF_RTC1->COUNTER; } /**@brief Function for computing the difference between two RTC1 counter values. * * @return Number of ticks elapsed from ticks_old to ticks_now. */ static __INLINE uint32_t ticks_diff_get(uint32_t ticks_now, uint32_t ticks_old) { return ((ticks_now - ticks_old) & MAX_RTC_COUNTER_VAL); } /**@brief Function for setting the RTC1 Capture Compare register 0, and enabling the corresponding * event. * * @param[in] value New value of Capture Compare register 0. */ static __INLINE void rtc1_compare0_set(uint32_t value) { NRF_RTC1->CC[0] = value; } /**@brief Function for inserting a timer in the timer list. * * @param[in] timer_id Id of timer to insert. */ static void timer_list_insert(app_timer_id_t timer_id) { timer_node_t * p_timer = &mp_nodes[timer_id]; if (m_timer_id_head == TIMER_NULL) { m_timer_id_head = timer_id; } else { if (p_timer->ticks_to_expire <= mp_nodes[m_timer_id_head].ticks_to_expire) { mp_nodes[m_timer_id_head].ticks_to_expire -= p_timer->ticks_to_expire; p_timer->next = m_timer_id_head; m_timer_id_head = timer_id; } else { app_timer_id_t previous; app_timer_id_t current; uint32_t ticks_to_expire; ticks_to_expire = p_timer->ticks_to_expire; previous = m_timer_id_head; current = m_timer_id_head; while ((current != TIMER_NULL) && (ticks_to_expire > mp_nodes[current].ticks_to_expire)) { ticks_to_expire -= mp_nodes[current].ticks_to_expire; previous = current; current = mp_nodes[current].next; } if (current != TIMER_NULL) { mp_nodes[current].ticks_to_expire -= ticks_to_expire; } p_timer->ticks_to_expire = ticks_to_expire; p_timer->next = current; mp_nodes[previous].next = timer_id; } } } /**@brief Function for removing a timer from the timer queue. * * @param[in] timer_id Id of timer to remove. */ static void timer_list_remove(app_timer_id_t timer_id) { app_timer_id_t previous; app_timer_id_t current; uint32_t timeout; // Find the timer's position in timer list previous = m_timer_id_head; current = previous; while (current != TIMER_NULL) { if (current == timer_id) { break; } previous = current; current = mp_nodes[current].next; } // Timer not in active list if (current == TIMER_NULL) { return; } // Timer is the first in the list if (previous == current) { m_timer_id_head = mp_nodes[m_timer_id_head].next; // No more timers in the list. Disable RTC1. if (m_timer_id_head == TIMER_NULL) { rtc1_stop(); } } // Remaining timeout between next timeout timeout = mp_nodes[current].ticks_to_expire; // Link previous timer with next of this timer, i.e. removing the timer from list mp_nodes[previous].next = mp_nodes[current].next; // If this is not the last timer, increment the next timer by this timer timeout current = mp_nodes[previous].next; if (current != TIMER_NULL) { mp_nodes[current].ticks_to_expire += timeout; } } /**@brief Function for scheduling a check for timeouts by generating a RTC1 interrupt. */ static void timer_timeouts_check_sched(void) { NVIC_SetPendingIRQ(RTC1_IRQn); } /**@brief Function for scheduling a timer list update by generating a SWI0 interrupt. */ static void timer_list_handler_sched(void) { NVIC_SetPendingIRQ(SWI0_IRQn); } /**@brief Function for executing an application timeout handler, either by calling it directly, or * by passing an event to the @ref app_scheduler. * * @param[in] p_timer Pointer to expired timer. */ static void timeout_handler_exec(timer_node_t * p_timer) { if (m_evt_schedule_func != NULL) { uint32_t err_code = m_evt_schedule_func(p_timer->p_timeout_handler, p_timer->p_context); APP_ERROR_CHECK(err_code); } else { p_timer->p_timeout_handler(p_timer->p_context); } } /**@brief Function for checking for expired timers. */ static void timer_timeouts_check(void) { // Handle expired of timer if (m_timer_id_head != TIMER_NULL) { app_timer_id_t timer_id; uint32_t ticks_elapsed; uint32_t ticks_expired; // Initialize actual elapsed ticks being consumed to 0 ticks_expired = 0; // ticks_elapsed is collected here, job will use it ticks_elapsed = ticks_diff_get(rtc1_counter_get(), m_ticks_latest); // Auto variable containing the head of timers expiring timer_id = m_timer_id_head; // Expire all timers within ticks_elapsed and collect ticks_expired while (timer_id != TIMER_NULL) { timer_node_t * p_timer; // Auto variable for current timer node p_timer = &mp_nodes[timer_id]; // Do nothing if timer did not expire if (ticks_elapsed < p_timer->ticks_to_expire) { break; } // Decrement ticks_elapsed and collect expired ticks ticks_elapsed -= p_timer->ticks_to_expire; ticks_expired += p_timer->ticks_to_expire; // Move to next timer timer_id = p_timer->next; // Execute Task timeout_handler_exec(p_timer); } // Prepare to queue the ticks expired in the m_ticks_elapsed queue. if (m_ticks_elapsed_q_read_ind == m_ticks_elapsed_q_write_ind) { // The read index of the queue is equal to the write index. This means the new // value of ticks_expired should be stored at a new location in the m_ticks_elapsed // queue (which is implemented as a double buffer). // Check if there will be a queue overflow. if (++m_ticks_elapsed_q_write_ind == CONTEXT_QUEUE_SIZE_MAX) { // There will be a queue overflow. Hence the write index should point to the start // of the queue. m_ticks_elapsed_q_write_ind = 0; } } // Queue the ticks expired. m_ticks_elapsed[m_ticks_elapsed_q_write_ind] = ticks_expired; timer_list_handler_sched(); } } /**@brief Function for acquiring the number of ticks elapsed. * * @param[out] p_ticks_elapsed Number of ticks elapsed. * * @return TRUE if elapsed ticks was read from queue, FALSE otherwise. */ static bool elapsed_ticks_acquire(uint32_t * p_ticks_elapsed) { // Pick the elapsed value from queue if (m_ticks_elapsed_q_read_ind != m_ticks_elapsed_q_write_ind) { // Dequeue elapsed value m_ticks_elapsed_q_read_ind++; if (m_ticks_elapsed_q_read_ind == CONTEXT_QUEUE_SIZE_MAX) { m_ticks_elapsed_q_read_ind = 0; } *p_ticks_elapsed = m_ticks_elapsed[m_ticks_elapsed_q_read_ind]; m_ticks_latest += *p_ticks_elapsed; m_ticks_latest &= MAX_RTC_COUNTER_VAL; return true; } else { // No elapsed value in queue *p_ticks_elapsed = 0; return false; } } /**@brief Function for handling the timer list deletions. * * @return TRUE if Capture Compare register must be updated, FALSE otherwise. */ static bool list_deletions_handler(void) { app_timer_id_t timer_id_old_head; uint8_t user_id; // Remember the old head, so as to decide if new compare needs to be set timer_id_old_head = m_timer_id_head; user_id = m_user_array_size; while (user_id--) { timer_user_t * p_user = &mp_users[user_id]; uint8_t user_ops_first = p_user->first; while (user_ops_first != p_user->last) { timer_node_t * p_timer; timer_user_op_t * p_user_op = &p_user->p_user_op_queue[user_ops_first]; // Traverse to next operation in queue user_ops_first++; if (user_ops_first == p_user->user_op_queue_size) { user_ops_first = 0; } switch (p_user_op->op_type) { case TIMER_USER_OP_TYPE_STOP: // Delete node if timer is running p_timer = &mp_nodes[p_user_op->timer_id]; if (p_timer->is_running) { timer_list_remove(p_user_op->timer_id); p_timer->is_running = false; } break; case TIMER_USER_OP_TYPE_STOP_ALL: // Delete list of running timers, and mark all timers as not running while (m_timer_id_head != TIMER_NULL) { timer_node_t * p_head = &mp_nodes[m_timer_id_head]; p_head->is_running = false; m_timer_id_head = p_head->next; } break; default: // No implementation needed. break; } } } // Detect change in head of the list return (m_timer_id_head != timer_id_old_head); } /**@brief Function for updating the timer list for expired timers. * * @param[in] ticks_elapsed Number of elapsed ticks. * @param[in] ticks_previous Previous known value of the RTC counter. * @param[out] p_restart_list_head List of repeating timers to be restarted. */ static void expired_timers_handler(uint32_t ticks_elapsed, uint32_t ticks_previous, app_timer_id_t * p_restart_list_head) { uint32_t ticks_expired = 0; while (m_timer_id_head != TIMER_NULL) { timer_node_t * p_timer; app_timer_id_t id_expired; // Auto variable for current timer node p_timer = &mp_nodes[m_timer_id_head]; // Do nothing if timer did not expire if (ticks_elapsed < p_timer->ticks_to_expire) { p_timer->ticks_to_expire -= ticks_elapsed; break; } // Decrement ticks_elapsed and collect expired ticks ticks_elapsed -= p_timer->ticks_to_expire; ticks_expired += p_timer->ticks_to_expire; // Timer expired, set ticks_to_expire zero p_timer->ticks_to_expire = 0; p_timer->is_running = false; // Remove the expired timer from head id_expired = m_timer_id_head; m_timer_id_head = p_timer->next; // Timer will be restarted if periodic if (p_timer->ticks_periodic_interval != 0) { p_timer->ticks_at_start = (ticks_previous + ticks_expired) & MAX_RTC_COUNTER_VAL; p_timer->ticks_first_interval = p_timer->ticks_periodic_interval; p_timer->next = *p_restart_list_head; *p_restart_list_head = id_expired; } } } /**@brief Function for handling timer list insertions. * * @param[in] p_restart_list_head List of repeating timers to be restarted. * * @return TRUE if Capture Compare register must be updated, FALSE otherwise. */ static bool list_insertions_handler(app_timer_id_t restart_list_head) { app_timer_id_t timer_id_old_head; uint8_t user_id; // Remember the old head, so as to decide if new compare needs to be set timer_id_old_head = m_timer_id_head; user_id = m_user_array_size; while (user_id--) { timer_user_t * p_user = &mp_users[user_id]; // Handle insertions of timers while ((restart_list_head != TIMER_NULL) || (p_user->first != p_user->last)) { app_timer_id_t id_start; timer_node_t * p_timer; if (restart_list_head != TIMER_NULL) { id_start = restart_list_head; p_timer = &mp_nodes[id_start]; restart_list_head = p_timer->next; } else { timer_user_op_t * p_user_op = &p_user->p_user_op_queue[p_user->first]; p_user->first++; if (p_user->first == p_user->user_op_queue_size) { p_user->first = 0; } id_start = p_user_op->timer_id; p_timer = &mp_nodes[id_start]; if ((p_user_op->op_type != TIMER_USER_OP_TYPE_START) || p_timer->is_running) { continue; } p_timer->ticks_at_start = p_user_op->params.start.ticks_at_start; p_timer->ticks_first_interval = p_user_op->params.start.ticks_first_interval; p_timer->ticks_periodic_interval = p_user_op->params.start.ticks_periodic_interval; p_timer->p_context = p_user_op->params.start.p_context; } // Prepare the node to be inserted if ( ((p_timer->ticks_at_start - m_ticks_latest) & MAX_RTC_COUNTER_VAL) < (MAX_RTC_COUNTER_VAL / 2) ) { p_timer->ticks_to_expire = ticks_diff_get(p_timer->ticks_at_start, m_ticks_latest) + p_timer->ticks_first_interval; } else { uint32_t delta_current_start; delta_current_start = ticks_diff_get(m_ticks_latest, p_timer->ticks_at_start); if (p_timer->ticks_first_interval > delta_current_start) { p_timer->ticks_to_expire = p_timer->ticks_first_interval - delta_current_start; } else { p_timer->ticks_to_expire = 0; } } p_timer->ticks_at_start = 0; p_timer->ticks_first_interval = 0; p_timer->is_running = true; p_timer->next = TIMER_NULL; // Insert into list timer_list_insert(id_start); } } return (m_timer_id_head != timer_id_old_head); } /**@brief Function for updating the Capture Compare register. */ static void compare_reg_update(app_timer_id_t timer_id_head_old) { // Setup the timeout for timers on the head of the list if (m_timer_id_head != TIMER_NULL) { uint32_t ticks_to_expire = mp_nodes[m_timer_id_head].ticks_to_expire; uint32_t pre_counter_val = rtc1_counter_get(); uint32_t cc = m_ticks_latest; uint32_t ticks_elapsed = ticks_diff_get(pre_counter_val, cc) + RTC_COMPARE_OFFSET_MIN; if (!m_rtc1_running) { // No timers were already running, start RTC rtc1_start(); } cc += (ticks_elapsed < ticks_to_expire) ? ticks_to_expire : ticks_elapsed; cc &= MAX_RTC_COUNTER_VAL; rtc1_compare0_set(cc); uint32_t post_counter_val = rtc1_counter_get(); if ((ticks_diff_get(post_counter_val, pre_counter_val) + RTC_COMPARE_OFFSET_MIN) > ticks_diff_get(cc, pre_counter_val)) { // When this happens the COMPARE event may not be triggered by the RTC. // The nRF51 Series User Specification states that if the COUNTER value is N // (i.e post_counter_val = N), writing N or N+1 to a CC register may not trigger a // COMPARE event. Hence the RTC interrupt is forcefully pended by calling the following // function. timer_timeouts_check_sched(); } } else { // No timers are running, stop RTC rtc1_stop(); } } /**@brief Function for handling changes to the timer list. */ static void timer_list_handler(void) { app_timer_id_t restart_list_head = TIMER_NULL; uint32_t ticks_elapsed; uint32_t ticks_previous; bool ticks_have_elapsed; bool compare_update; app_timer_id_t timer_id_head_old; // Back up the previous known tick and previous list head ticks_previous = m_ticks_latest; timer_id_head_old = m_timer_id_head; // Get number of elapsed ticks ticks_have_elapsed = elapsed_ticks_acquire(&ticks_elapsed); // Handle list deletions compare_update = list_deletions_handler(); // Handle expired timers if (ticks_have_elapsed) { expired_timers_handler(ticks_elapsed, ticks_previous, &restart_list_head); compare_update = true; } // Handle list insertions if (list_insertions_handler(restart_list_head)) { compare_update = true; } // Update compare register if necessary if (compare_update) { compare_reg_update(timer_id_head_old); } } /**@brief Function for enqueueing a new operations queue entry. * * @param[in] p_user User that the entry is to be enqueued for. * @param[in] last_index Index of the next last index to be enqueued. */ static void user_op_enque(timer_user_t * p_user, app_timer_id_t last_index) { p_user->last = last_index; } /**@brief Function for allocating a new operations queue entry. * * @param[in] p_user User that the entry is to be allocated for. * @param[out] p_last_index Index of the next last index to be enqueued. * * @return Pointer to allocated queue entry, or NULL if queue is full. */ static timer_user_op_t * user_op_alloc(timer_user_t * p_user, app_timer_id_t * p_last_index) { app_timer_id_t last; timer_user_op_t * p_user_op; last = p_user->last + 1; if (last == p_user->user_op_queue_size) { // Overflow case. last = 0; } if (last == p_user->first) { // Queue is full. return NULL; } *p_last_index = last; p_user_op = &p_user->p_user_op_queue[p_user->last]; return p_user_op; } /**@brief Function for scheduling a Timer Start operation. * * @param[in] user_id Id of user calling this function. * @param[in] timer_id Id of timer to start. * @param[in] timeout_initial Time (in ticks) to first timer expiry. * @param[in] timeout_periodic Time (in ticks) between periodic expiries. * @param[in] p_context General purpose pointer. Will be passed to the timeout handler when * the timer expires. * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t timer_start_op_schedule(timer_user_id_t user_id, app_timer_id_t timer_id, uint32_t timeout_initial, uint32_t timeout_periodic, void * p_context) { app_timer_id_t last_index; timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index); if (p_user_op == NULL) { return NRF_ERROR_NO_MEM; } p_user_op->op_type = TIMER_USER_OP_TYPE_START; p_user_op->timer_id = timer_id; p_user_op->params.start.ticks_at_start = rtc1_counter_get(); p_user_op->params.start.ticks_first_interval = timeout_initial; p_user_op->params.start.ticks_periodic_interval = timeout_periodic; p_user_op->params.start.p_context = p_context; user_op_enque(&mp_users[user_id], last_index); timer_list_handler_sched(); return NRF_SUCCESS; } /**@brief Function for scheduling a Timer Stop operation. * * @param[in] user_id Id of user calling this function. * @param[in] timer_id Id of timer to stop. * * @return NRF_SUCCESS on successful scheduling a timer stop operation. NRF_ERROR_NO_MEM when there * is no memory left to schedule the timer stop operation. */ static uint32_t timer_stop_op_schedule(timer_user_id_t user_id, app_timer_id_t timer_id) { app_timer_id_t last_index; timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index); if (p_user_op == NULL) { return NRF_ERROR_NO_MEM; } p_user_op->op_type = TIMER_USER_OP_TYPE_STOP; p_user_op->timer_id = timer_id; user_op_enque(&mp_users[user_id], last_index); timer_list_handler_sched(); return NRF_SUCCESS; } /**@brief Function for scheduling a Timer Stop All operation. * * @param[in] user_id Id of user calling this function. */ static uint32_t timer_stop_all_op_schedule(timer_user_id_t user_id) { app_timer_id_t last_index; timer_user_op_t * p_user_op = user_op_alloc(&mp_users[user_id], &last_index); if (p_user_op == NULL) { return NRF_ERROR_NO_MEM; } p_user_op->op_type = TIMER_USER_OP_TYPE_STOP_ALL; p_user_op->timer_id = TIMER_NULL; user_op_enque(&mp_users[user_id], last_index); timer_list_handler_sched(); return NRF_SUCCESS; } /**@brief Function for handling the RTC1 interrupt. * * @details Checks for timeouts, and executes timeout handlers for expired timers. */ void RTC1_IRQHandler(void) { // Clear all events (also unexpected ones) NRF_RTC1->EVENTS_COMPARE[0] = 0; NRF_RTC1->EVENTS_COMPARE[1] = 0; NRF_RTC1->EVENTS_COMPARE[2] = 0; NRF_RTC1->EVENTS_COMPARE[3] = 0; NRF_RTC1->EVENTS_TICK = 0; if (NRF_RTC1->EVENTS_OVRFLW) { overflowBits += (1 << 24); } NRF_RTC1->EVENTS_OVRFLW = 0; // Check for expired timers timer_timeouts_check(); } /**@brief Function for handling the SWI0 interrupt. * * @details Performs all updates to the timer list. */ void SWI0_IRQHandler(void) { timer_list_handler(); } uint32_t app_timer_init(uint32_t prescaler, uint8_t max_timers, uint8_t op_queues_size, void * p_buffer, app_timer_evt_schedule_func_t evt_schedule_func) { int i; // Check that buffer is correctly aligned if (!is_word_aligned(p_buffer)) { return NRF_ERROR_INVALID_PARAM; } // Check for NULL buffer if (p_buffer == NULL) { return NRF_ERROR_INVALID_PARAM; } // Stop RTC to prevent any running timers from expiring (in case of reinitialization) rtc1_stop(); m_evt_schedule_func = evt_schedule_func; // Initialize timer node array m_node_array_size = max_timers; mp_nodes = (timer_node_t *) p_buffer; for (i = 0; i < max_timers; i++) { mp_nodes[i].state = STATE_FREE; mp_nodes[i].is_running = false; } // Skip timer node array p_buffer = &((uint8_t *)p_buffer)[max_timers * sizeof(timer_node_t)]; // Initialize users array m_user_array_size = APP_TIMER_INT_LEVELS; mp_users = (timer_user_t *) p_buffer; // Skip user array p_buffer = &((uint8_t *)p_buffer)[APP_TIMER_INT_LEVELS * sizeof(timer_user_t)]; // Initialize operation queues for (i = 0; i < APP_TIMER_INT_LEVELS; i++) { timer_user_t * p_user = &mp_users[i]; p_user->first = 0; p_user->last = 0; p_user->user_op_queue_size = op_queues_size; p_user->p_user_op_queue = (timer_user_op_t *) p_buffer; // Skip operation queue p_buffer = &((uint8_t *)p_buffer)[op_queues_size * sizeof(timer_user_op_t)]; } m_timer_id_head = TIMER_NULL; m_ticks_elapsed_q_read_ind = 0; m_ticks_elapsed_q_write_ind = 0; NVIC_ClearPendingIRQ(SWI0_IRQn); NVIC_SetPriority(SWI0_IRQn, SWI0_IRQ_PRI); NVIC_EnableIRQ(SWI0_IRQn); rtc1_init(prescaler); rtc1_start(); m_ticks_latest = rtc1_counter_get(); return NRF_SUCCESS; } uint32_t app_timer_create(app_timer_id_t * p_timer_id, app_timer_mode_t mode, app_timer_timeout_handler_t timeout_handler) { int i; // Check state and parameters if (mp_nodes == NULL) { return NRF_ERROR_INVALID_STATE; } if (timeout_handler == NULL) { return NRF_ERROR_INVALID_PARAM; } if (p_timer_id == NULL) { return NRF_ERROR_INVALID_PARAM; } // Find free timer for (i = 0; i < m_node_array_size; i++) { if (mp_nodes[i].state == STATE_FREE) { mp_nodes[i].state = STATE_ALLOCATED; mp_nodes[i].mode = mode; mp_nodes[i].p_timeout_handler = timeout_handler; *p_timer_id = i; return NRF_SUCCESS; } } return NRF_ERROR_NO_MEM; } /**@brief Function for creating a timer user id from the current interrupt level. * * @return Timer user id. */ static timer_user_id_t user_id_get(void) { timer_user_id_t ret; STATIC_ASSERT(APP_TIMER_INT_LEVELS == 3); switch (current_int_priority_get()) { case APP_IRQ_PRIORITY_HIGH: ret = APP_HIGH_USER_ID; break; case APP_IRQ_PRIORITY_LOW: ret = APP_LOW_USER_ID; break; default: ret = THREAD_MODE_USER_ID; break; } return ret; } uint32_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context) { uint32_t timeout_periodic; // Check state and parameters if (mp_nodes == NULL) { return NRF_ERROR_INVALID_STATE; } if ((timer_id >= m_node_array_size) || (timeout_ticks < APP_TIMER_MIN_TIMEOUT_TICKS)) { return NRF_ERROR_INVALID_PARAM; } if (mp_nodes[timer_id].state != STATE_ALLOCATED) { return NRF_ERROR_INVALID_STATE; } // Schedule timer start operation timeout_periodic = (mp_nodes[timer_id].mode == APP_TIMER_MODE_REPEATED) ? timeout_ticks : 0; return timer_start_op_schedule(user_id_get(), timer_id, timeout_ticks, timeout_periodic, p_context); } uint32_t app_timer_stop(app_timer_id_t timer_id) { // Check state and parameters if (mp_nodes == NULL) { return NRF_ERROR_INVALID_STATE; } if (timer_id >= m_node_array_size) { return NRF_ERROR_INVALID_PARAM; } if (mp_nodes[timer_id].state != STATE_ALLOCATED) { return NRF_ERROR_INVALID_STATE; } // Schedule timer stop operation return timer_stop_op_schedule(user_id_get(), timer_id); } uint32_t app_timer_stop_all(void) { // Check state if (mp_nodes == NULL) { return NRF_ERROR_INVALID_STATE; } return timer_stop_all_op_schedule(user_id_get()); } uint32_t app_timer_cnt_get(uint64_t * p_ticks) { *p_ticks = overflowBits | rtc1_counter_get(); return NRF_SUCCESS; } uint32_t app_timer_cnt_diff_compute(uint32_t ticks_to, uint32_t ticks_from, uint32_t * p_ticks_diff) { *p_ticks_diff = ticks_diff_get(ticks_to, ticks_from); return NRF_SUCCESS; }