1 /* 2 * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #include <stdbool.h> 8 #include "soc/soc_caps.h" 9 #include "esp_err.h" 10 11 #ifdef __cplusplus 12 extern "C" { 13 #endif 14 15 /** 16 * @brief This function is used to enable the digital RC_FAST clock, 17 * to support the peripherals. 18 * 19 * @note If this function is called a number of times, the `periph_rtc_dig_clk8m_disable` 20 * function needs to be called same times to disable. 21 * 22 * @return true: success for enable the RC_FAST clock, false: RC_FAST clock enable failed 23 */ 24 bool periph_rtc_dig_clk8m_enable(void); 25 26 /** 27 * @brief This function is used to disable the digital RC_FAST clock, which should be called 28 * with the `periph_rtc_dig_clk8m_enable` pairedly 29 * 30 * @note If this function is called a number of times, the `periph_rtc_dig_clk8m_disable` 31 * function needs to be called same times to disable. 32 */ 33 void periph_rtc_dig_clk8m_disable(void); 34 35 /** 36 * @brief This function is used to get the real clock frequency value of RC_FAST clock 37 * 38 * @return The real clock value, in Hz 39 */ 40 uint32_t periph_rtc_dig_clk8m_get_freq(void); 41 42 #if SOC_CLK_APLL_SUPPORTED 43 /** 44 * @brief Enable APLL power if it has not enabled 45 */ 46 void periph_rtc_apll_acquire(void); 47 48 /** 49 * @brief Shut down APLL power if no peripherals using APLL 50 */ 51 void periph_rtc_apll_release(void); 52 53 /** 54 * @brief Calculate and set APLL coefficients by given frequency 55 * @note Have to call 'periph_rtc_apll_acquire' to enable APLL power before setting frequency 56 * @note This calculation is based on the inequality: 57 * xtal_freq * (4 + sdm2 + sdm1/256 + sdm0/65536) >= SOC_APLL_MULTIPLIER_OUT_MIN_HZ(350 MHz) 58 * It will always calculate the minimum coefficients that can satisfy the inequality above, instead of loop them one by one. 59 * which means more appropriate coefficients are likely to exist. 60 * But this algorithm can meet almost all the cases and the accuracy can be guaranteed as well. 61 * @note The APLL frequency is only allowed to set when there is only one peripheral refer to it. 62 * If APLL is already set by another peripheral, this function will return `ESP_ERR_INVALID_STATE` 63 * and output the current frequency by parameter `real_freq`. 64 * 65 * @param expt_freq Expected APLL frequency (unit: Hz) 66 * @param real_freq APLL real working frequency [output] (unit: Hz) 67 * @return 68 * - ESP_OK: APLL frequency set success 69 * - ESP_ERR_INVALID_ARG: The input expt_freq is out of APLL support range 70 * - ESP_ERR_INVALID_STATE: APLL is refered by more than one peripherals, not allowed to change its frequency now 71 */ 72 esp_err_t periph_rtc_apll_freq_set(uint32_t expt_freq, uint32_t *real_freq); 73 #endif // SOC_CLK_APLL_SUPPORTED 74 75 #ifdef __cplusplus 76 } 77 #endif 78
