| /** |
| * Copyright (c) 2016 - 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 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 the copyright holder nor the names of its |
| * contributors 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. |
| */ |
| #include <nrfx.h> |
| |
| #if NRFX_CHECK(NRFX_SYSTICK_ENABLED) |
| #include <nrfx_systick.h> |
| |
| /** |
| * @brief Maximum number of ticks to delay |
| * |
| * The maximum number of ticks should be much lower than |
| * Physical maximum count of the SysTick timer. |
| * It is dictated by the fact that it would be impossible to detect delay |
| * properly when the timer value warps around the starting point. |
| */ |
| #define NRFX_SYSTICK_TICKS_MAX (NRF_SYSTICK_VAL_MASK / 2UL) |
| |
| /** |
| * @brief Number of milliseconds in a second |
| */ |
| #define NRFX_SYSTICK_MS (1000UL) |
| |
| /** |
| * @brief Number of microseconds in a second |
| */ |
| #define NRFX_SYSTICK_US (1000UL * NRFX_SYSTICK_MS) |
| |
| /** |
| * @brief Number of milliseconds to wait in single loop |
| * |
| * Constant used by @ref nrd_drv_systick_delay_ms function |
| * to split waiting into loops and rest. |
| * |
| * It describes the number of milliseconds to wait in single loop. |
| * |
| * See @ref nrfx_systick_delay_ms source code for details. |
| */ |
| #define NRFX_SYSTICK_MS_STEP (64U) |
| |
| /** |
| * @brief Checks if the given time is in correct range |
| * |
| * Function tests given time is not to big for this library. |
| * Assertion is used for testing. |
| * |
| * @param us Time in microseconds to check |
| */ |
| #define NRFX_SYSTICK_ASSERT_TIMEOUT(us) \ |
| NRFX_ASSERT(us <= (NRFX_SYSTICK_TICKS_MAX / ((SystemCoreClock) / NRFX_SYSTICK_US))); |
| |
| /** |
| * @brief Function that converts microseconds to ticks |
| * |
| * Function converts from microseconds to CPU ticks. |
| * |
| * @param us Number of microseconds |
| * |
| * @return Number of ticks |
| * |
| * @sa nrfx_systick_ms_tick |
| */ |
| static inline uint32_t nrfx_systick_us_tick(uint32_t us) |
| { |
| return us * ((SystemCoreClock) / NRFX_SYSTICK_US); |
| } |
| |
| /** |
| * @brief Function that converts milliseconds to ticks |
| * |
| * Function converts from milliseconds to CPU ticks. |
| * |
| * @param us Number of milliseconds |
| * |
| * @return Number of ticks |
| * |
| * @sa nrfx_systick_us_tick |
| */ |
| static inline uint32_t nrfx_systick_ms_tick(uint32_t ms) |
| { |
| return ms * ((SystemCoreClock) / NRFX_SYSTICK_MS); |
| } |
| |
| void nrfx_systick_init(void) |
| { |
| nrf_systick_load_set(NRF_SYSTICK_VAL_MASK); |
| nrf_systick_csr_set( |
| NRF_SYSTICK_CSR_CLKSOURCE_CPU | |
| NRF_SYSTICK_CSR_TICKINT_DISABLE | |
| NRF_SYSTICK_CSR_ENABLE); |
| } |
| |
| void nrfx_systick_get(nrfx_systick_state_t * p_state) |
| { |
| p_state->time = nrf_systick_val_get(); |
| } |
| |
| bool nrfx_systick_test(nrfx_systick_state_t const * p_state, uint32_t us) |
| { |
| NRFX_SYSTICK_ASSERT_TIMEOUT(us); |
| |
| const uint32_t diff = NRF_SYSTICK_VAL_MASK & ((p_state->time) - nrf_systick_val_get()); |
| return (diff >= nrfx_systick_us_tick(us)); |
| } |
| |
| void nrfx_systick_delay_ticks(uint32_t ticks) |
| { |
| NRFX_ASSERT(ticks <= NRFX_SYSTICK_TICKS_MAX); |
| |
| const uint32_t start = nrf_systick_val_get(); |
| while ((NRF_SYSTICK_VAL_MASK & (start - nrf_systick_val_get())) < ticks) |
| { |
| /* Nothing to do */ |
| } |
| } |
| |
| void nrfx_systick_delay_us(uint32_t us) |
| { |
| NRFX_SYSTICK_ASSERT_TIMEOUT(us); |
| nrfx_systick_delay_ticks(nrfx_systick_us_tick(us)); |
| } |
| |
| void nrfx_systick_delay_ms(uint32_t ms) |
| { |
| uint32_t n = ms / NRFX_SYSTICK_MS_STEP; |
| uint32_t r = ms % NRFX_SYSTICK_MS_STEP; |
| while (0 != (n--)) |
| { |
| nrfx_systick_delay_ticks(nrfx_systick_ms_tick(NRFX_SYSTICK_MS_STEP)); |
| } |
| nrfx_systick_delay_ticks(nrfx_systick_ms_tick(r)); |
| } |
| |
| #endif // NRFX_CHECK(NRFX_SYSTICK_ENABLED) |