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Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/timer/app_timer.c')
| -rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/timer/app_timer.c | 1075 |
1 files changed, 1075 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/timer/app_timer.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/timer/app_timer.c new file mode 100644 index 0000000..0df49b7 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/components/libraries/timer/app_timer.c @@ -0,0 +1,1075 @@ +/** + * Copyright (c) 2012 - 2018, Nordic Semiconductor ASA + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form, except as embedded into a Nordic + * Semiconductor ASA integrated circuit in a product or a software update for + * such product, must reproduce the above copyright notice, this list of + * conditions and the following disclaimer in the documentation and/or other + * materials provided with the distribution. + * + * 3. Neither the name of Nordic Semiconductor ASA nor the names of its + * contributors may be used to endorse or promote products derived from this + * software without specific prior written permission. + * + * 4. This software, with or without modification, must only be used with a + * Nordic Semiconductor ASA integrated circuit. + * + * 5. Any software provided in binary form under this license must not be reverse + * engineered, decompiled, modified and/or disassembled. + * + * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS + * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE + * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +#include "sdk_common.h" +#if NRF_MODULE_ENABLED(APP_TIMER) +#include "app_timer.h" +#include <stdlib.h> +#include "nrf.h" +#include "nrf_peripherals.h" +#include "nrf_soc.h" +#include "app_error.h" +#include "nrf_delay.h" +#include "app_util_platform.h" +#if APP_TIMER_CONFIG_USE_SCHEDULER +#include "app_scheduler.h" +#endif + +#define RTC1_IRQ_PRI APP_TIMER_CONFIG_IRQ_PRIORITY /**< Priority of the RTC1 interrupt (used for checking for timeouts and executing timeout handlers). */ +#define SWI_IRQ_PRI APP_TIMER_CONFIG_IRQ_PRIORITY /**< Priority of the SWI 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 == SWI_IRQ_PRI); + +#define MAX_RTC_COUNTER_VAL 0x00FFFFFF /**< Maximum value of the RTC counter. */ + +#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. */ + +#ifdef EGU_PRESENT +#define SWI_PART(_id) CONCAT_2(SWI,_id) +#define EGU_PART(_id) CONCAT_2(_EGU,_id) +#define SWI_IRQ_n(_id) CONCAT_3(SWI_PART(_id), EGU_PART(_id),_IRQn) +#define SWI_IRQ_Handler_n(_id) CONCAT_3(SWI_PART(_id), EGU_PART(_id),_IRQHandler) +#else //EGU_PRESENT +#define SWI_IRQ_n(_id) CONCAT_3(SWI,_id,_IRQn) +#define SWI_IRQ_Handler_n(_id) CONCAT_3(SWI,_id,_IRQHandler) +#endif + +#define SWI_IRQn SWI_IRQ_n(APP_TIMER_CONFIG_SWI_NUMBER) +#define SWI_IRQHandler SWI_IRQ_Handler_n(APP_TIMER_CONFIG_SWI_NUMBER) + + +#define MODULE_INITIALIZED (m_op_queue.size != 0) /**< Macro designating whether the module has been initialized properly. */ + +/**@brief Timer node type. The nodes will be used form a linked list of running timers. */ +typedef struct +{ + 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_mode_t mode; /**< Timer mode. */ + 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. */ + void * next; /**< Pointer to the next node. */ +} timer_node_t; + +STATIC_ASSERT(sizeof(timer_node_t) == APP_TIMER_NODE_SIZE); + +/**@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; /**< Id of timer on which the operation is to be performed. */ + timer_node_t * p_node; + union + { + timer_user_op_start_t start; /**< Structure describing a timer start operation. */ + } params; +} timer_user_op_t; + +/**@brief Structure describing a timer operations queue. + * + * @details This queue will hold timer operations issued by the application + * until the timer interrupt handler processes these operations. + */ +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 size; /**< Queue size. */ + timer_user_op_t user_op_queue[APP_TIMER_CONFIG_OP_QUEUE_SIZE+1]; /**< Queue buffer. */ +} timer_op_queue_t; + +STATIC_ASSERT(sizeof(timer_op_queue_t) % 4 == 0); + +#define CONTEXT_QUEUE_SIZE_MAX (2) + +static timer_op_queue_t m_op_queue; /**< Timer operations queue. */ +static timer_node_t * mp_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 bool m_rtc1_running; /**< Boolean indicating if RTC1 is running. */ +static bool m_rtc1_reset; /**< Boolean indicating if RTC1 counter has been reset due to last timer removed from timer list during the timer list handling. */ + +#if APP_TIMER_WITH_PROFILER +static uint8_t m_max_user_op_queue_utilization; /**< Maximum observed timer user operations queue utilization. */ +#endif + +/**@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) +{ + NRF_RTC1->EVTENSET = RTC_EVTEN_COMPARE0_Msk; + NRF_RTC1->INTENSET = RTC_INTENSET_COMPARE0_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) +{ + NVIC_DisableIRQ(RTC1_IRQn); + + NRF_RTC1->EVTENCLR = RTC_EVTEN_COMPARE0_Msk; + NRF_RTC1->INTENCLR = RTC_INTENSET_COMPARE0_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(timer_node_t * p_timer) +{ + if (mp_timer_id_head == NULL) + { + mp_timer_id_head = p_timer; + } + else + { + if (p_timer->ticks_to_expire <= mp_timer_id_head->ticks_to_expire) + { + mp_timer_id_head->ticks_to_expire -= p_timer->ticks_to_expire; + + p_timer->next = mp_timer_id_head; + mp_timer_id_head = p_timer; + } + else + { + timer_node_t * p_previous; + timer_node_t * p_current; + uint32_t ticks_to_expire; + + ticks_to_expire = p_timer->ticks_to_expire; + p_previous = mp_timer_id_head; + p_current = mp_timer_id_head; + + while ((p_current != NULL) && (ticks_to_expire > p_current->ticks_to_expire)) + { + ticks_to_expire -= p_current->ticks_to_expire; + p_previous = p_current; + p_current = p_current->next; + } + + if (p_current != NULL) + { + p_current->ticks_to_expire -= ticks_to_expire; + } + + p_timer->ticks_to_expire = ticks_to_expire; + p_timer->next = p_current; + p_previous->next = p_timer; + } + } +} + + +/**@brief Function for removing a timer from the timer queue. + * + * @param[in] timer_id Id of timer to remove. + * + * @return TRUE if Capture Compare register must be updated, FALSE otherwise. + */ +static bool timer_list_remove(timer_node_t * p_timer) +{ + timer_node_t * p_old_head; + timer_node_t * p_previous; + timer_node_t * p_current; + uint32_t timeout; + + // Find the timer's position in timer list. + p_old_head = mp_timer_id_head; + p_previous = mp_timer_id_head; + p_current = p_previous; + + while (p_current != NULL) + { + if (p_current == p_timer) + { + break; + } + p_previous = p_current; + p_current = p_current->next; + } + + // Timer not in active list. + if (p_current == NULL) + { + return false; + } + + // Timer is the first in the list + if (p_previous == p_current) + { + mp_timer_id_head = mp_timer_id_head->next; + + // No more timers in the list. Reset RTC1 in case Start timer operations are present in the queue. + if (mp_timer_id_head == NULL) + { + NRF_RTC1->TASKS_CLEAR = 1; + m_ticks_latest = 0; + m_rtc1_reset = true; + nrf_delay_us(MAX_RTC_TASKS_DELAY); + } + } + + // Remaining timeout between next timeout. + timeout = p_current->ticks_to_expire; + + // Link previous timer with next of this timer, i.e. removing the timer from list. + p_previous->next = p_current->next; + + // If this is not the last timer, increment the next timer by this timer timeout. + p_current = p_previous->next; + if (p_current != NULL) + { + p_current->ticks_to_expire += timeout; + } + + return (p_old_head != mp_timer_id_head); +} + + +/**@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 SWI interrupt. + */ +static void timer_list_handler_sched(void) +{ + NVIC_SetPendingIRQ(SWI_IRQn); +} + +#if APP_TIMER_CONFIG_USE_SCHEDULER +static void timeout_handler_scheduled_exec(void * p_event_data, uint16_t event_size) +{ + APP_ERROR_CHECK_BOOL(event_size == sizeof(app_timer_event_t)); + app_timer_event_t const * p_timer_event = (app_timer_event_t *)p_event_data; + + p_timer_event->timeout_handler(p_timer_event->p_context); +} +#endif + +/**@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 APP_TIMER_CONFIG_USE_SCHEDULER + app_timer_event_t timer_event; + + timer_event.timeout_handler = p_timer->p_timeout_handler; + timer_event.p_context = p_timer->p_context; + uint32_t err_code = app_sched_event_put(&timer_event, sizeof(timer_event), timeout_handler_scheduled_exec); + APP_ERROR_CHECK(err_code); +#else + p_timer->p_timeout_handler(p_timer->p_context); +#endif +} + + +/**@brief Function for checking for expired timers. + */ +static void timer_timeouts_check(void) +{ + // Handle expired of timer + if (mp_timer_id_head != NULL) + { + timer_node_t * p_timer; + timer_node_t * p_previous_timer; + 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. + p_timer = mp_timer_id_head; + + // Expire all timers within ticks_elapsed and collect ticks_expired. + while (p_timer != NULL) + { + // 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. + p_previous_timer = p_timer; + p_timer = p_timer->next; + + // Execute Task. + if (p_previous_timer->is_running) + { + p_previous_timer->is_running = false; + timeout_handler_exec(p_previous_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 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, + timer_node_t ** p_restart_list_head) +{ + uint32_t ticks_expired = 0; + + while (mp_timer_id_head != NULL) + { + timer_node_t * p_timer; + timer_node_t * p_timer_expired; + + // Auto variable for current timer node. + p_timer = mp_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; + + // Remove the expired timer from head. + p_timer_expired = mp_timer_id_head; + mp_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 = p_timer_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(timer_node_t * p_restart_list_head) +{ + bool compare_update = false; + + timer_node_t * p_timer_id_old_head; + + // Remember the old head, so as to decide if new compare needs to be set. + p_timer_id_old_head = mp_timer_id_head; + + // Handle insertions of timers. + while ((p_restart_list_head != NULL) || (m_op_queue.first != m_op_queue.last)) + { + timer_node_t * p_timer; + + if (p_restart_list_head != NULL) + { + p_timer = p_restart_list_head; + p_restart_list_head = p_timer->next; + } + else + { + timer_user_op_t * p_user_op = &m_op_queue.user_op_queue[m_op_queue.first]; + + m_op_queue.first++; + if (m_op_queue.first == m_op_queue.size) + { + m_op_queue.first = 0; + } + + p_timer = p_user_op->p_node; + + switch (p_user_op->op_type) + { + case TIMER_USER_OP_TYPE_STOP: + // Delete node if timer is running. + if (timer_list_remove(p_user_op->p_node)) + { + compare_update = true; + } + + p_timer->is_running = false; + continue; + + case TIMER_USER_OP_TYPE_STOP_ALL: + // Delete list of running timers, and mark all timers as not running. + while (mp_timer_id_head != NULL) + { + timer_node_t * p_head = mp_timer_id_head; + + p_head->is_running = false; + mp_timer_id_head = p_head->next; + } + continue; + case TIMER_USER_OP_TYPE_START: + break; + default: + // No implementation needed. + continue; + } + + if (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; + + if (m_rtc1_reset) + { + p_timer->ticks_at_start = 0; + } + } + + // 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 = NULL; + + // Insert into list + timer_list_insert(p_timer); + } + + return (compare_update || (mp_timer_id_head != p_timer_id_old_head)); +} + + +/**@brief Function for updating the Capture Compare register. + */ +static void compare_reg_update(timer_node_t * p_timer_id_head_old) +{ + // Setup the timeout for timers on the head of the list + if (mp_timer_id_head != NULL) + { + uint32_t ticks_to_expire = mp_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. + rtc1_compare0_set(rtc1_counter_get()); // this should prevent CC to fire again in the background while the code is in RTC-ISR + nrf_delay_us(MAX_RTC_TASKS_DELAY); + timer_timeouts_check_sched(); + } + } + else + { +#if (APP_TIMER_KEEPS_RTC_ACTIVE == 0) + // No timers are running, stop RTC + rtc1_stop(); +#endif //(APP_TIMER_KEEPS_RTC_ACTIVE == 0) + } +} + + +/**@brief Function for handling changes to the timer list. + */ +static void timer_list_handler(void) +{ + timer_node_t * p_restart_list_head = NULL; + + uint32_t ticks_elapsed; + uint32_t ticks_previous; + bool ticks_have_elapsed; + bool compare_update = false; + timer_node_t * p_timer_id_head_old; + +#if APP_TIMER_WITH_PROFILER + { + uint8_t size = m_op_queue.size; + uint8_t first = m_op_queue.first; + uint8_t last = m_op_queue.last; + uint8_t utilization = (first <= last) ? (last - first) : (size + 1 - first + last); + + if (utilization > m_max_user_op_queue_utilization) + { + m_max_user_op_queue_utilization = utilization; + } + } +#endif + + // Back up the previous known tick and previous list head + ticks_previous = m_ticks_latest; + p_timer_id_head_old = mp_timer_id_head; + + // Get number of elapsed ticks + ticks_have_elapsed = elapsed_ticks_acquire(&ticks_elapsed); + + // Handle expired timers + if (ticks_have_elapsed) + { + expired_timers_handler(ticks_elapsed, ticks_previous, &p_restart_list_head); + compare_update = true; + } + + + // Handle list insertions + if (list_insertions_handler(p_restart_list_head)) + { + compare_update = true; + } + + // Update compare register if necessary + if (compare_update) + { + compare_reg_update(p_timer_id_head_old); + } + m_rtc1_reset = false; +} + + +/**@brief Function for enqueueing a new operations queue entry. + * + * @param[in] last_index Index of the next last index to be enqueued. + */ +static void user_op_enque(uint8_t last_index) +{ + m_op_queue.last = last_index; +} + + +/**@brief Function for allocating a new operations queue entry. + * + * @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( uint8_t * p_last_index) +{ + uint8_t last; + timer_user_op_t * p_user_op; + + last = m_op_queue.last + 1; + if (last == m_op_queue.size) + { + // Overflow case. + last = 0; + } + if (last == m_op_queue.first) + { + // Queue is full. + return NULL; + } + + *p_last_index = last; + p_user_op = &m_op_queue.user_op_queue[m_op_queue.last]; + + return p_user_op; +} + + +/**@brief Function for scheduling a Timer Start operation. + * + * @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_node_t * p_node, + uint32_t timeout_initial, + uint32_t timeout_periodic, + void * p_context) +{ + uint8_t last_index; + uint32_t err_code = NRF_SUCCESS; + + CRITICAL_REGION_ENTER(); + timer_user_op_t * p_user_op = user_op_alloc(&last_index); + if (p_user_op == NULL) + { + err_code = NRF_ERROR_NO_MEM; + } + else + { + p_user_op->op_type = TIMER_USER_OP_TYPE_START; + p_user_op->p_node = p_node; + 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(last_index); + } + CRITICAL_REGION_EXIT(); + + if (err_code == NRF_SUCCESS) + { + timer_list_handler_sched(); + } + + return err_code; +} + + +/**@brief Function for scheduling a Timer Stop operation. + * + * @param[in] timer_id Id of timer to stop. + * @param[in] op_type Type of stop operation + * + * @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_node_t * p_node, + timer_user_op_type_t op_type) +{ + uint8_t last_index; + uint32_t err_code = NRF_SUCCESS; + + CRITICAL_REGION_ENTER(); + timer_user_op_t * p_user_op = user_op_alloc(&last_index); + if (p_user_op == NULL) + { + err_code = NRF_ERROR_NO_MEM; + } + else + { + p_user_op->op_type = op_type; + p_user_op->p_node = p_node; + + user_op_enque(last_index); + } + CRITICAL_REGION_EXIT(); + + if (err_code == NRF_SUCCESS) + { + timer_list_handler_sched(); + } + + return err_code; +} + +/**@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; + NRF_RTC1->EVENTS_OVRFLW = 0; + + // Check for expired timers + timer_timeouts_check(); +} + + +/**@brief Function for handling the SWI interrupt. + * + * @details Performs all updates to the timer list. + */ +void SWI_IRQHandler(void) +{ + timer_list_handler(); +} + + +ret_code_t app_timer_init(void) +{ + // Stop RTC to prevent any running timers from expiring (in case of reinitialization) + rtc1_stop(); + + // Initialize operation queue + m_op_queue.first = 0; + m_op_queue.last = 0; + m_op_queue.size = APP_TIMER_CONFIG_OP_QUEUE_SIZE+1; + + mp_timer_id_head = NULL; + m_ticks_elapsed_q_read_ind = 0; + m_ticks_elapsed_q_write_ind = 0; + +#if APP_TIMER_WITH_PROFILER + m_max_user_op_queue_utilization = 0; +#endif + + NVIC_ClearPendingIRQ(SWI_IRQn); + NVIC_SetPriority(SWI_IRQn, SWI_IRQ_PRI); + NVIC_EnableIRQ(SWI_IRQn); + + rtc1_init(APP_TIMER_CONFIG_RTC_FREQUENCY); + + m_ticks_latest = rtc1_counter_get(); + + return NRF_SUCCESS; +} + + +ret_code_t app_timer_create(app_timer_id_t const * p_timer_id, + app_timer_mode_t mode, + app_timer_timeout_handler_t timeout_handler) +{ + // Check state and parameters + VERIFY_MODULE_INITIALIZED(); + + if (timeout_handler == NULL) + { + return NRF_ERROR_INVALID_PARAM; + } + if (p_timer_id == NULL) + { + return NRF_ERROR_INVALID_PARAM; + } + if (((timer_node_t*)*p_timer_id)->is_running) + { + return NRF_ERROR_INVALID_STATE; + } + + timer_node_t * p_node = (timer_node_t *)*p_timer_id; + p_node->is_running = false; + p_node->mode = mode; + p_node->p_timeout_handler = timeout_handler; + return NRF_SUCCESS; +} + +ret_code_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context) +{ + uint32_t timeout_periodic; + timer_node_t * p_node = (timer_node_t*)timer_id; + + // Check state and parameters + VERIFY_MODULE_INITIALIZED(); + + if (timer_id == 0) + { + return NRF_ERROR_INVALID_STATE; + } + if (timeout_ticks < APP_TIMER_MIN_TIMEOUT_TICKS) + { + return NRF_ERROR_INVALID_PARAM; + } + if (p_node->p_timeout_handler == NULL) + { + return NRF_ERROR_INVALID_STATE; + } + + // Schedule timer start operation + timeout_periodic = (p_node->mode == APP_TIMER_MODE_REPEATED) ? timeout_ticks : 0; + + return timer_start_op_schedule(p_node, + timeout_ticks, + timeout_periodic, + p_context); +} + + +ret_code_t app_timer_stop(app_timer_id_t timer_id) +{ + timer_node_t * p_node = (timer_node_t*)timer_id; + // Check state and parameters + VERIFY_MODULE_INITIALIZED(); + + if ((timer_id == NULL) || (p_node->p_timeout_handler == NULL)) + { + return NRF_ERROR_INVALID_STATE; + } + + p_node->is_running = false; + + // Schedule timer stop operation + return timer_stop_op_schedule(p_node, TIMER_USER_OP_TYPE_STOP); +} + + +ret_code_t app_timer_stop_all(void) +{ + // Check state + VERIFY_MODULE_INITIALIZED(); + + return timer_stop_op_schedule(NULL, TIMER_USER_OP_TYPE_STOP_ALL); +} + + +uint32_t app_timer_cnt_get(void) +{ + return rtc1_counter_get(); +} + + +uint32_t app_timer_cnt_diff_compute(uint32_t ticks_to, + uint32_t ticks_from) +{ + return ticks_diff_get(ticks_to, ticks_from); +} + +#if APP_TIMER_WITH_PROFILER +uint8_t app_timer_op_queue_utilization_get(void) +{ + return m_max_user_op_queue_utilization; +} +#endif + +void app_timer_pause(void) +{ + NRF_RTC1->TASKS_STOP = 1; +} + +void app_timer_resume(void) +{ + NRF_RTC1->TASKS_START = 1; +} + +#endif //NRF_MODULE_ENABLED(APP_TIMER) |