esp-idf/components/esp_hw_support/port/esp32p4/rtc_clk_init.c

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4.3 KiB
C

/*
* SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include "esp32p4/rom/ets_sys.h"
#include "esp32p4/rom/rtc.h"
#include "esp32p4/rom/uart.h"
#include "soc/rtc.h"
#include "esp_cpu.h"
#include "regi2c_ctrl.h"
#include "soc/lp_clkrst_reg.h"
#include "soc/regi2c_dig_reg.h"
#include "esp_hw_log.h"
#include "sdkconfig.h"
#include "esp_rom_uart.h"
#include "esp_private/esp_pmu.h"
#include "hal/clk_tree_ll.h"
static const char *TAG = "rtc_clk_init";
#if SOC_PMU_SUPPORTED
/**
* Initialize the ICG map of some modem clock domains in the PMU_ACTIVE state
*
* A pre-initialization interface is used to initialize the ICG map of the
* MODEM_APB, I2C_MST and LP_APB clock domains in the PMU_ACTIVE state, and
* disable the clock gating of these clock domains in the PMU_ACTIVE state,
* because the system clock source (PLL) in the system boot up process needs
* to use the i2c master peripheral.
*
* ICG map of all modem clock domains under different power states (PMU_ACTIVE,
* PMU_MODEM and PMU_SLEEP) will be initialized in esp_perip_clk_init().
*/
static void rtc_clk_modem_clock_domain_active_state_icg_map_preinit(void)
{
/* Configure modem ICG code in PMU_ACTIVE state */
pmu_ll_hp_set_icg_modem(&PMU, PMU_MODE_HP_ACTIVE, PMU_HP_ICG_MODEM_CODE_ACTIVE);
/* Disable clock gating for MODEM_APB, I2C_MST and LP_APB clock domains in PMU_ACTIVE state */
modem_syscon_ll_set_modem_apb_icg_bitmap(&MODEM_SYSCON, BIT(PMU_HP_ICG_MODEM_CODE_ACTIVE));
modem_lpcon_ll_set_i2c_master_icg_bitmap(&MODEM_LPCON, BIT(PMU_HP_ICG_MODEM_CODE_ACTIVE));
modem_lpcon_ll_set_lp_apb_icg_bitmap(&MODEM_LPCON, BIT(PMU_HP_ICG_MODEM_CODE_ACTIVE));
/* Software trigger force update modem ICG code and ICG switch */
pmu_ll_imm_update_dig_icg_modem_code(&PMU, true);
pmu_ll_imm_update_dig_icg_switch(&PMU, true);
}
#endif //#if SOC_PMU_SUPPORTED
void rtc_clk_init(rtc_clk_config_t cfg)
{
rtc_cpu_freq_config_t old_config, new_config;
#if SOC_PMU_SUPPORTED
rtc_clk_modem_clock_domain_active_state_icg_map_preinit();
#endif //#if SOC_PMU_SUPPORTED
/* Set tuning parameters for RC_FAST, RC_SLOW, and RC32K clocks.
* Note: this doesn't attempt to set the clocks to precise frequencies.
* Instead, we calibrate these clocks against XTAL frequency later, when necessary.
* - SCK_DCAP value controls tuning of RC_SLOW clock.
* The higher the value of DCAP is, the lower is the frequency.
* - CK8M_DFREQ value controls tuning of RC_FAST clock.
* CLK_8M_DFREQ constant gives the best temperature characteristics.
* - RC32K_DFREQ value controls tuning of RC32K clock.
*/
REG_SET_FIELD(LP_CLKRST_FOSC_CNTL_REG, LP_CLKRST_FOSC_DFREQ, cfg.clk_8m_dfreq);
REGI2C_WRITE_MASK(I2C_DIG_REG, I2C_DIG_REG_SCK_DCAP, cfg.slow_clk_dcap);
REG_SET_FIELD(LP_CLKRST_RC32K_CNTL_REG, LP_CLKRST_RC32K_DFREQ, cfg.rc32k_dfreq);
rtc_xtal_freq_t xtal_freq = cfg.xtal_freq;
esp_rom_uart_tx_wait_idle(0);
rtc_clk_xtal_freq_update(xtal_freq);
/* Set CPU frequency */
rtc_clk_cpu_freq_get_config(&old_config);
uint32_t freq_before = old_config.freq_mhz;
bool res = rtc_clk_cpu_freq_mhz_to_config(cfg.cpu_freq_mhz, &new_config);
if (!res) {
ESP_HW_LOGE(TAG, "invalid CPU frequency value");
abort();
}
rtc_clk_cpu_freq_set_config(&new_config);
/* Re-calculate the ccount to make time calculation correct. */
esp_cpu_set_cycle_count( (uint64_t)esp_cpu_get_cycle_count() * cfg.cpu_freq_mhz / freq_before );
/* Slow & fast clocks setup */
// We will not power off RC_FAST in bootloader stage even if it is not being used as any
// cpu / rtc_fast / rtc_slow clock sources, this is because RNG always needs it in the bootloader stage.
bool need_rc_fast_en = true;
if (cfg.slow_clk_src == SOC_RTC_SLOW_CLK_SRC_XTAL32K) {
rtc_clk_32k_enable(true);
} else if (cfg.slow_clk_src == SOC_RTC_SLOW_CLK_SRC_OSC_SLOW) {
rtc_clk_32k_enable_external();
} else if (cfg.slow_clk_src == SOC_RTC_SLOW_CLK_SRC_RC32K) {
rtc_clk_rc32k_enable(true);
}
rtc_clk_8m_enable(need_rc_fast_en);
rtc_clk_fast_src_set(cfg.fast_clk_src);
rtc_clk_slow_src_set(cfg.slow_clk_src);
}