/* * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include "sdkconfig.h" #include "esp_attr.h" #include "esp_log.h" #include "esp_clk_internal.h" #include "esp32c61/rom/ets_sys.h" #include "esp32c61/rom/uart.h" #include "soc/soc.h" #include "soc/rtc.h" #include "soc/rtc_periph.h" #include "esp_cpu.h" #include "hal/wdt_hal.h" #include "esp_private/esp_modem_clock.h" #include "esp_private/periph_ctrl.h" #include "esp_private/esp_clk.h" #include "esp_private/esp_pmu.h" #include "esp_rom_uart.h" #include "esp_rom_sys.h" #include "ocode_init.h" // TODO: [ESP32C61] IDF-9249 /* Number of cycles to wait from the 32k XTAL oscillator to consider it running. * Larger values increase startup delay. Smaller values may cause false positive * detection (i.e. oscillator runs for a few cycles and then stops). */ #define SLOW_CLK_CAL_CYCLES CONFIG_RTC_CLK_CAL_CYCLES #define MHZ (1000000) static void select_rtc_slow_clk(soc_rtc_slow_clk_src_t rtc_slow_clk_src); static const char *TAG = "clk"; __attribute__((weak)) void esp_clk_init(void) { #if !CONFIG_IDF_ENV_FPGA pmu_init(); if (esp_rom_get_reset_reason(0) == RESET_REASON_CHIP_POWER_ON) { esp_ocode_calib_init(); } assert(rtc_clk_xtal_freq_get() == SOC_XTAL_FREQ_40M); rtc_clk_8m_enable(true); rtc_clk_fast_src_set(SOC_RTC_FAST_CLK_SRC_RC_FAST); #endif #ifdef CONFIG_BOOTLOADER_WDT_ENABLE // WDT uses a SLOW_CLK clock source. After a function select_rtc_slow_clk a frequency of this source can changed. // If the frequency changes from 150kHz to 32kHz, then the timeout set for the WDT will increase 4.6 times. // Therefore, for the time of frequency change, set a new lower timeout value (1.6 sec). // This prevents excessive delay before resetting in case the supply voltage is drawdown. // (If frequency is changed from 150kHz to 32kHz then WDT timeout will increased to 1.6sec * 150/32 = 7.5 sec). wdt_hal_context_t rtc_wdt_ctx = RWDT_HAL_CONTEXT_DEFAULT(); uint32_t stage_timeout_ticks = (uint32_t)(1600ULL * rtc_clk_slow_freq_get_hz() / 1000ULL); wdt_hal_write_protect_disable(&rtc_wdt_ctx); wdt_hal_feed(&rtc_wdt_ctx); //Bootloader has enabled RTC WDT until now. We're only modifying timeout, so keep the stage and timeout action the same wdt_hal_config_stage(&rtc_wdt_ctx, WDT_STAGE0, stage_timeout_ticks, WDT_STAGE_ACTION_RESET_RTC); wdt_hal_write_protect_enable(&rtc_wdt_ctx); #endif #if defined(CONFIG_RTC_CLK_SRC_EXT_CRYS) select_rtc_slow_clk(SOC_RTC_SLOW_CLK_SRC_XTAL32K); #elif defined(CONFIG_RTC_CLK_SRC_EXT_OSC) select_rtc_slow_clk(SOC_RTC_SLOW_CLK_SRC_OSC_SLOW); #elif defined(CONFIG_RTC_CLK_SRC_INT_RC32K) select_rtc_slow_clk(SOC_RTC_SLOW_CLK_SRC_RC32K); #else select_rtc_slow_clk(SOC_RTC_SLOW_CLK_SRC_RC_SLOW); #endif #ifdef CONFIG_BOOTLOADER_WDT_ENABLE // After changing a frequency WDT timeout needs to be set for new frequency. stage_timeout_ticks = (uint32_t)((uint64_t)CONFIG_BOOTLOADER_WDT_TIME_MS * rtc_clk_slow_freq_get_hz() / 1000); wdt_hal_write_protect_disable(&rtc_wdt_ctx); wdt_hal_feed(&rtc_wdt_ctx); wdt_hal_config_stage(&rtc_wdt_ctx, WDT_STAGE0, stage_timeout_ticks, WDT_STAGE_ACTION_RESET_RTC); wdt_hal_write_protect_enable(&rtc_wdt_ctx); #endif rtc_cpu_freq_config_t old_config, new_config; rtc_clk_cpu_freq_get_config(&old_config); const uint32_t old_freq_mhz = old_config.freq_mhz; const uint32_t new_freq_mhz = CONFIG_ESP_DEFAULT_CPU_FREQ_MHZ; bool res = rtc_clk_cpu_freq_mhz_to_config(new_freq_mhz, &new_config); assert(res); // Wait for UART TX to finish, otherwise some UART output will be lost // when switching APB frequency esp_rom_output_tx_wait_idle(CONFIG_ESP_CONSOLE_ROM_SERIAL_PORT_NUM); if (res) { 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() * new_freq_mhz / old_freq_mhz); } static void select_rtc_slow_clk(soc_rtc_slow_clk_src_t rtc_slow_clk_src) { uint32_t cal_val = 0; /* number of times to repeat 32k XTAL calibration * before giving up and switching to the internal RC */ int retry_32k_xtal = 3; do { if (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_XTAL32K || rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_OSC_SLOW) { /* 32k XTAL oscillator needs to be enabled and running before it can * be used. Hardware doesn't have a direct way of checking if the * oscillator is running. Here we use rtc_clk_cal function to count * the number of main XTAL cycles in the given number of 32k XTAL * oscillator cycles. If the 32k XTAL has not started up, calibration * will time out, returning 0. */ ESP_EARLY_LOGD(TAG, "waiting for 32k oscillator to start up"); rtc_cal_sel_t cal_sel = 0; if (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_XTAL32K) { rtc_clk_32k_enable(true); cal_sel = RTC_CAL_32K_XTAL; } else if (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_OSC_SLOW) { rtc_clk_32k_enable_external(); cal_sel = RTC_CAL_32K_OSC_SLOW; } // When SLOW_CLK_CAL_CYCLES is set to 0, clock calibration will not be performed at startup. if (SLOW_CLK_CAL_CYCLES > 0) { cal_val = rtc_clk_cal(cal_sel, SLOW_CLK_CAL_CYCLES); if (cal_val == 0) { if (retry_32k_xtal-- > 0) { continue; } ESP_EARLY_LOGW(TAG, "32 kHz clock not found, switching to internal 150 kHz oscillator"); rtc_slow_clk_src = SOC_RTC_SLOW_CLK_SRC_RC_SLOW; } } } else if (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_RC32K) { rtc_clk_rc32k_enable(true); } rtc_clk_slow_src_set(rtc_slow_clk_src); if (SLOW_CLK_CAL_CYCLES > 0) { /* TODO: 32k XTAL oscillator has some frequency drift at startup. * Improve calibration routine to wait until the frequency is stable. */ cal_val = rtc_clk_cal(RTC_CAL_RTC_MUX, SLOW_CLK_CAL_CYCLES); } else { const uint64_t cal_dividend = (1ULL << RTC_CLK_CAL_FRACT) * 1000000ULL; cal_val = (uint32_t)(cal_dividend / rtc_clk_slow_freq_get_hz()); } } while (cal_val == 0); ESP_EARLY_LOGD(TAG, "RTC_SLOW_CLK calibration value: %d", cal_val); esp_clk_slowclk_cal_set(cal_val); } void rtc_clk_select_rtc_slow_clk(void) { select_rtc_slow_clk(SOC_RTC_SLOW_CLK_SRC_XTAL32K); } /* This function is not exposed as an API at this point. * All peripheral clocks are default enabled after chip is powered on. * This function disables some peripheral clocks when cpu starts. * These peripheral clocks are enabled when the peripherals are initialized * and disabled when they are de-initialized. */ __attribute__((weak)) void esp_perip_clk_init(void) { /* During system initialization, the low-power clock source of the modem * (WiFi, BLE or Coexist) follows the configuration of the slow clock source * of the system. If the WiFi, BLE or Coexist module needs a higher * precision sleep clock (for example, the BLE needs to use the main XTAL * oscillator (40 MHz) to provide the clock during the sleep process in some * scenarios), the module needs to switch to the required clock source by * itself. */ //TODO - WIFI-5233 soc_rtc_slow_clk_src_t rtc_slow_clk_src = rtc_clk_slow_src_get(); modem_clock_lpclk_src_t modem_lpclk_src = (modem_clock_lpclk_src_t)( (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_RC_SLOW) ? MODEM_CLOCK_LPCLK_SRC_RC_SLOW : (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_XTAL32K) ? MODEM_CLOCK_LPCLK_SRC_XTAL32K : (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_RC32K) ? MODEM_CLOCK_LPCLK_SRC_RC32K : (rtc_slow_clk_src == SOC_RTC_SLOW_CLK_SRC_OSC_SLOW) ? MODEM_CLOCK_LPCLK_SRC_EXT32K : SOC_RTC_SLOW_CLK_SRC_RC_SLOW); modem_clock_select_lp_clock_source(PERIPH_WIFI_MODULE, modem_lpclk_src, 0); ESP_EARLY_LOGW(TAG, "esp_perip_clk_init() has not been implemented yet"); }