Mustahsin Chowdhury
Nordic stack and drivers for the mbed BLE API
Fork of
nRF51822
by 
Nordic Semiconductor
Diff: TARGET_MCU_NRF51822/sdk/source/libraries/timer/app_timer.h
- Revision:
- 640:c90ae1400bf2
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/TARGET_MCU_NRF51822/sdk/source/libraries/timer/app_timer.h Wed Sep 14 14:39:43 2016 +0100
@@ -0,0 +1,297 @@
+/*
+ * Copyright (c) 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 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 other
+ * contributors to this software may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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.
+ *
+ */
+
+/** @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 <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#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);
+
+#endif // APP_TIMER_H__
+
+/** @} */