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app_timer.h
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00001 /* 00002 * Copyright (c) Nordic Semiconductor ASA 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without modification, 00006 * are permitted provided that the following conditions are met: 00007 * 00008 * 1. Redistributions of source code must retain the above copyright notice, this 00009 * list of conditions and the following disclaimer. 00010 * 00011 * 2. Redistributions in binary form must reproduce the above copyright notice, this 00012 * list of conditions and the following disclaimer in the documentation and/or 00013 * other materials provided with the distribution. 00014 * 00015 * 3. Neither the name of Nordic Semiconductor ASA nor the names of other 00016 * contributors to this software may be used to endorse or promote products 00017 * derived from this software without specific prior written permission. 00018 * 00019 * 00020 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 00021 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 00022 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00023 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 00024 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00025 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00026 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 00027 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00028 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00029 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00030 * 00031 */ 00032 00033 /** @file 00034 * 00035 * @defgroup app_timer Application Timer 00036 * @{ 00037 * @ingroup app_common 00038 * 00039 * @brief Application timer functionality. 00040 * 00041 * @details This module enables the application to create multiple timer instances based on the RTC1 00042 * peripheral. Checking for time-outs and invokation of user time-out handlers is performed 00043 * in the RTC1 interrupt handler. List handling is done using a software interrupt (SWI0). 00044 * Both interrupt handlers are running in APP_LOW priority level. 00045 * 00046 * @details When calling app_timer_start() or app_timer_stop(), the timer operation is just queued, 00047 * and the software interrupt is triggered. The actual timer start/stop operation is 00048 * executed by the SWI0 interrupt handler. Since the SWI0 interrupt is running in APP_LOW, 00049 * if the application code calling the timer function is running in APP_LOW or APP_HIGH, 00050 * the timer operation will not be performed until the application handler has returned. 00051 * This will be the case, for example, when stopping a timer from a time-out handler when not using 00052 * the scheduler. 00053 * 00054 * @details Use the USE_SCHEDULER parameter of the APP_TIMER_INIT() macro to select if the 00055 * @ref app_scheduler should be used or not. Even if the scheduler is 00056 * not used, app_timer.h will include app_scheduler.h, so when 00057 * compiling, app_scheduler.h must be available in one of the compiler include paths. 00058 */ 00059 00060 #ifndef APP_TIMER_H__ 00061 #define APP_TIMER_H__ 00062 00063 #include <stdint.h> 00064 #include <stdbool.h> 00065 #include <stdio.h> 00066 #include "app_error.h " 00067 #include "app_util.h " 00068 #include "compiler_abstraction.h" 00069 00070 #define APP_TIMER_CLOCK_FREQ 32768 /**< Clock frequency of the RTC timer used to implement the app timer module. */ 00071 #define APP_TIMER_MIN_TIMEOUT_TICKS 5 /**< Minimum value of the timeout_ticks parameter of app_timer_start(). */ 00072 00073 #define APP_TIMER_NODE_SIZE 32 /**< Size of app_timer.timer_node_t (used to allocate data). */ 00074 #define APP_TIMER_USER_OP_SIZE 24 /**< Size of app_timer.timer_user_op_t (only for use inside APP_TIMER_BUF_SIZE()). */ 00075 #define APP_TIMER_USER_SIZE 8 /**< Size of app_timer.timer_user_t (only for use inside APP_TIMER_BUF_SIZE()). */ 00076 #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()). */ 00077 00078 /**@brief Compute number of bytes required to hold the application timer data structures. 00079 * 00080 * @param[in] OP_QUEUE_SIZE Size of queues holding timer operations that are pending execution. 00081 * Note that due to the queue implementation, this size must be one more 00082 * than the size that is actually needed. 00083 * 00084 * @return Required application timer buffer size (in bytes). 00085 */ 00086 #define APP_TIMER_BUF_SIZE(OP_QUEUE_SIZE) \ 00087 ( \ 00088 ( \ 00089 APP_TIMER_INT_LEVELS \ 00090 * \ 00091 (APP_TIMER_USER_SIZE + ((OP_QUEUE_SIZE) + 1) * APP_TIMER_USER_OP_SIZE) \ 00092 ) \ 00093 ) 00094 00095 /**@brief Convert milliseconds to timer ticks. 00096 * 00097 * This macro uses 64-bit integer arithmetic, but as long as the macro parameters are 00098 * constants (i.e. defines), the computation will be done by the preprocessor. 00099 * 00100 * When using this macro, ensure that the 00101 * values provided as input result in an output value that is supported by the 00102 * @ref app_timer_start function. For example, when the ticks for 1 ms is needed, the 00103 * maximum possible value of PRESCALER must be 6, when @ref APP_TIMER_CLOCK_FREQ is 32768. 00104 * This will result in a ticks value as 5. Any higher value for PRESCALER will result in a 00105 * ticks value that is not supported by this module. 00106 * 00107 * @param[in] MS Milliseconds. 00108 * @param[in] PRESCALER Value of the RTC1 PRESCALER register (must be the same value that was 00109 * passed to APP_TIMER_INIT()). 00110 * 00111 * @return Number of timer ticks. 00112 */ 00113 #define APP_TIMER_TICKS(MS, PRESCALER)\ 00114 ((uint32_t)ROUNDED_DIV((MS) * (uint64_t)APP_TIMER_CLOCK_FREQ, ((PRESCALER) + 1) * 1000)) 00115 00116 typedef struct app_timer_t { uint32_t data[CEIL_DIV(APP_TIMER_NODE_SIZE, sizeof(uint32_t))]; } app_timer_t; 00117 00118 /**@brief Timer ID type. 00119 * Never declare a variable of this type, but use the macro @ref APP_TIMER_DEF instead.*/ 00120 typedef app_timer_t * app_timer_id_t; 00121 00122 /** 00123 * @brief Create a timer identifier and statically allocate memory for the timer. 00124 * 00125 * @param timer_id Name of the timer identifier variable that will be used to control the timer. 00126 */ 00127 #define APP_TIMER_DEF(timer_id) \ 00128 static app_timer_t timer_id##_data = { {0} }; \ 00129 static const app_timer_id_t timer_id = &timer_id##_data 00130 00131 00132 /**@brief Application time-out handler type. */ 00133 typedef void (*app_timer_timeout_handler_t)(void * p_context); 00134 00135 /**@brief Type of function for passing events from the timer module to the scheduler. */ 00136 typedef uint32_t (*app_timer_evt_schedule_func_t) (app_timer_timeout_handler_t timeout_handler, 00137 void * p_context); 00138 00139 /**@brief Timer modes. */ 00140 typedef enum 00141 { 00142 APP_TIMER_MODE_SINGLE_SHOT, /**< The timer will expire only once. */ 00143 APP_TIMER_MODE_REPEATED /**< The timer will restart each time it expires. */ 00144 } app_timer_mode_t; 00145 00146 /**@brief Initialize the application timer module. 00147 * 00148 * @details This macro handles dimensioning and allocation of the memory buffer required by the timer, 00149 * making sure that the buffer is correctly aligned. It will also connect the timer module 00150 * to the scheduler (if specified). 00151 * 00152 * @note This module assumes that the LFCLK is already running. If it is not, the module will 00153 * be non-functional, since the RTC will not run. If you do not use a SoftDevice, you 00154 * must start the LFCLK manually. See the rtc_example's lfclk_config() function 00155 * for an example of how to do this. If you use a SoftDevice, the LFCLK is started on 00156 * SoftDevice init. 00157 * 00158 * 00159 * @param[in] PRESCALER Value of the RTC1 PRESCALER register. This will decide the 00160 * timer tick rate. Set to 0 for no prescaling. 00161 * @param[in] OP_QUEUES_SIZE Size of queues holding timer operations that are pending execution. 00162 * @param[in] SCHEDULER_FUNC Pointer to scheduler event handler 00163 * 00164 * @note Since this macro allocates a buffer, it must only be called once (it is OK to call it 00165 * several times as long as it is from the same location, for example, to do a re-initialization). 00166 */ 00167 /*lint -emacro(506, APP_TIMER_INIT) */ /* Suppress "Constant value Boolean */ 00168 #define APP_TIMER_INIT(PRESCALER, OP_QUEUES_SIZE, SCHEDULER_FUNC) \ 00169 do \ 00170 { \ 00171 static uint32_t APP_TIMER_BUF[CEIL_DIV(APP_TIMER_BUF_SIZE((OP_QUEUES_SIZE) + 1), \ 00172 sizeof(uint32_t))]; \ 00173 uint32_t ERR_CODE = app_timer_init((PRESCALER), \ 00174 (OP_QUEUES_SIZE) + 1, \ 00175 APP_TIMER_BUF, \ 00176 SCHEDULER_FUNC); \ 00177 APP_ERROR_CHECK(ERR_CODE); \ 00178 } while (0) 00179 00180 00181 00182 /**@brief Function for initializing the timer module. 00183 * 00184 * Normally, initialization should be done using the APP_TIMER_INIT() macro, because that macro will both 00185 * allocate the buffers needed by the timer module (including aligning the buffers correctly) 00186 * and take care of connecting the timer module to the scheduler (if specified). 00187 * 00188 * @param[in] prescaler Value of the RTC1 PRESCALER register. Set to 0 for no prescaling. 00189 * @param[in] op_queues_size Size of queues holding timer operations that are pending 00190 * execution. Note that due to the queue implementation, this size must 00191 * be one more than the size that is actually needed. 00192 * @param[in] p_buffer Pointer to memory buffer for internal use in the app_timer 00193 * module. The size of the buffer can be computed using the 00194 * APP_TIMER_BUF_SIZE() macro. The buffer must be aligned to a 00195 * 4 byte boundary. 00196 * @param[in] evt_schedule_func Function for passing time-out events to the scheduler. Point to 00197 * app_timer_evt_schedule() to connect to the scheduler. Set to NULL 00198 * to make the timer module call the time-out handler directly from 00199 * the timer interrupt handler. 00200 * 00201 * @retval NRF_SUCCESS If the module was initialized successfully. 00202 * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid (buffer not aligned to a 4 byte 00203 * boundary or NULL). 00204 */ 00205 uint32_t app_timer_init(uint32_t prescaler, 00206 uint8_t op_queues_size, 00207 void * p_buffer, 00208 app_timer_evt_schedule_func_t evt_schedule_func); 00209 00210 /**@brief Function for creating a timer instance. 00211 * 00212 * @param[in] p_timer_id Pointer to timer identifier. 00213 * @param[in] mode Timer mode. 00214 * @param[in] timeout_handler Function to be executed when the timer expires. 00215 * 00216 * @retval NRF_SUCCESS If the timer was successfully created. 00217 * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. 00218 * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or 00219 * the timer is running. 00220 * 00221 * @note This function does the timer allocation in the caller's context. It is also not protected 00222 * by a critical region. Therefore care must be taken not to call it from several interrupt 00223 * levels simultaneously. 00224 * @note The function can be called again on the timer instance and will re-initialize the instance if 00225 * the timer is not running. 00226 * @attention The FreeRTOS and RTX app_timer implementation does not allow app_timer_create to 00227 * be called on the previously initialized instance. 00228 */ 00229 uint32_t app_timer_create(app_timer_id_t const * p_timer_id, 00230 app_timer_mode_t mode, 00231 app_timer_timeout_handler_t timeout_handler); 00232 00233 /**@brief Function for starting a timer. 00234 * 00235 * @param[in] timer_id Timer identifier. 00236 * @param[in] timeout_ticks Number of ticks (of RTC1, including prescaling) to time-out event 00237 * (minimum 5 ticks). 00238 * @param[in] p_context General purpose pointer. Will be passed to the time-out handler when 00239 * the timer expires. 00240 * 00241 * @retval NRF_SUCCESS If the timer was successfully started. 00242 * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. 00243 * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or the timer 00244 * has not been created. 00245 * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. 00246 * 00247 * @note The minimum timeout_ticks value is 5. 00248 * @note For multiple active timers, time-outs occurring in close proximity to each other (in the 00249 * range of 1 to 3 ticks) will have a positive jitter of maximum 3 ticks. 00250 * @note When calling this method on a timer that is already running, the second start operation 00251 * is ignored. 00252 */ 00253 uint32_t app_timer_start(app_timer_id_t timer_id, uint32_t timeout_ticks, void * p_context); 00254 00255 /**@brief Function for stopping the specified timer. 00256 * 00257 * @param[in] timer_id Timer identifier. 00258 * 00259 * @retval NRF_SUCCESS If the timer was successfully stopped. 00260 * @retval NRF_ERROR_INVALID_PARAM If a parameter was invalid. 00261 * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized or the timer 00262 * has not been created. 00263 * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. 00264 */ 00265 uint32_t app_timer_stop(app_timer_id_t timer_id); 00266 00267 /**@brief Function for stopping all running timers. 00268 * 00269 * @retval NRF_SUCCESS If all timers were successfully stopped. 00270 * @retval NRF_ERROR_INVALID_STATE If the application timer module has not been initialized. 00271 * @retval NRF_ERROR_NO_MEM If the timer operations queue was full. 00272 */ 00273 uint32_t app_timer_stop_all(void); 00274 00275 /**@brief Function for returning the current value of the RTC1 counter. 00276 * 00277 * @param[out] p_ticks Current value of the RTC1 counter. 00278 * 00279 * @retval NRF_SUCCESS If the counter was successfully read. 00280 */ 00281 uint32_t app_timer_cnt_get(uint32_t * p_ticks); 00282 00283 /**@brief Function for computing the difference between two RTC1 counter values. 00284 * 00285 * @param[in] ticks_to Value returned by app_timer_cnt_get(). 00286 * @param[in] ticks_from Value returned by app_timer_cnt_get(). 00287 * @param[out] p_ticks_diff Number of ticks from ticks_from to ticks_to. 00288 * 00289 * @retval NRF_SUCCESS If the counter difference was successfully computed. 00290 */ 00291 uint32_t app_timer_cnt_diff_compute(uint32_t ticks_to, 00292 uint32_t ticks_from, 00293 uint32_t * p_ticks_diff); 00294 00295 #endif // APP_TIMER_H__ 00296 00297 /** @} */
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