/**
* Copyright (c) 2012 - 2017, 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_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. */
#if (APP_TIMER_CONFIG_SWI_NUMBER == 0)
#define SWI_IRQn SWI0_IRQn
#define SWI_IRQHandler SWI0_IRQHandler
#elif (APP_TIMER_CONFIG_SWI_NUMBER == 1)
#define SWI_IRQn SWI1_IRQn
#define SWI_IRQHandler SWI1_IRQHandler
#else
#error "Unsupported SWI number."
#endif
#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)