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esp-idf/components/esp_system/port/soc/esp32c3/clk.c
morris 16677b0d3c global: make periph enable/disable APIs private 
peripheral enable/disable usually should be managed by driver itself,
so make it as espressif private APIs, not recommended for user to use it
in application code.
However, if user want to re-write the driver or ports to other platform,
this is still possible by including the header in this way:
"esp_private/peripheral_ctrl.h"
2021-11-08 10:37:47 +08:00

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/*
* SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdint.h>
#include <sys/cdefs.h>
#include <sys/time.h>
#include <sys/param.h>
#include "sdkconfig.h"
#include "esp_attr.h"
#include "esp_log.h"
#include "esp32c3/clk.h"
#include "esp_clk_internal.h"
#include "esp32c3/rom/ets_sys.h"
#include "esp32c3/rom/uart.h"
#include "soc/system_reg.h"
#include "soc/dport_access.h"
#include "soc/soc.h"
#include "soc/rtc.h"
#include "soc/rtc_periph.h"
#include "soc/i2s_reg.h"
#include "hal/cpu_hal.h"
#include "hal/wdt_hal.h"
#include "esp_private/periph_ctrl.h"
#include "bootloader_clock.h"
#include "soc/syscon_reg.h"
#include "esp_rom_uart.h"
#include "esp_rom_sys.h"
/* 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_ESP32C3_RTC_CLK_CAL_CYCLES
#define MHZ (1000000)
/* Lower threshold for a reasonably-looking calibration value for a 32k XTAL.
* The ideal value (assuming 32768 Hz frequency) is 1000000/32768*(2**19) = 16*10^6.
*/
#define MIN_32K_XTAL_CAL_VAL 15000000L
/* Indicates that this 32k oscillator gets input from external oscillator, rather
* than a crystal.
*/
#define EXT_OSC_FLAG BIT(3)
/* This is almost the same as rtc_slow_freq_t, except that we define
* an extra enum member for the external 32k oscillator.
* For convenience, lower 2 bits should correspond to rtc_slow_freq_t values.
*/
typedef enum {
SLOW_CLK_RTC = RTC_SLOW_FREQ_RTC, //!< Internal 150 kHz RC oscillator
SLOW_CLK_32K_XTAL = RTC_SLOW_FREQ_32K_XTAL, //!< External 32 kHz XTAL
SLOW_CLK_8MD256 = RTC_SLOW_FREQ_8MD256, //!< Internal 8 MHz RC oscillator, divided by 256
SLOW_CLK_32K_EXT_OSC = RTC_SLOW_FREQ_32K_XTAL | EXT_OSC_FLAG //!< External 32k oscillator connected to 32K_XP pin
} slow_clk_sel_t;
static void select_rtc_slow_clk(slow_clk_sel_t slow_clk);
static const char *TAG = "clk";
__attribute__((weak)) void esp_clk_init(void)
{
#if !CONFIG_IDF_ENV_FPGA
rtc_config_t cfg = RTC_CONFIG_DEFAULT();
soc_reset_reason_t rst_reas;
rst_reas = esp_rom_get_reset_reason(0);
if (rst_reas == RESET_REASON_CHIP_POWER_ON) {
cfg.cali_ocode = 1;
}
rtc_init(cfg);
assert(rtc_clk_xtal_freq_get() == RTC_XTAL_FREQ_40M);
rtc_clk_fast_freq_set(RTC_FAST_FREQ_8M);
#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 = {.inst = WDT_RWDT, .rwdt_dev = &RTCCNTL};
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_ESP32C3_RTC_CLK_SRC_EXT_CRYS)
select_rtc_slow_clk(SLOW_CLK_32K_XTAL);
#elif defined(CONFIG_ESP32C3_RTC_CLK_SRC_EXT_OSC)
select_rtc_slow_clk(SLOW_CLK_32K_EXT_OSC);
#elif defined(CONFIG_ESP32C3_RTC_CLK_SRC_INT_8MD256)
select_rtc_slow_clk(SLOW_CLK_8MD256);
#else
select_rtc_slow_clk(RTC_SLOW_FREQ_RTC);
#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_ESP32C3_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_uart_tx_wait_idle(CONFIG_ESP_CONSOLE_UART_NUM);
if (res) {
rtc_clk_cpu_freq_set_config(&new_config);
}
// Re calculate the ccount to make time calculation correct.
cpu_hal_set_cycle_count( (uint64_t)cpu_hal_get_cycle_count() * new_freq_mhz / old_freq_mhz );
}
static void select_rtc_slow_clk(slow_clk_sel_t slow_clk)
{
rtc_slow_freq_t rtc_slow_freq = slow_clk & RTC_CNTL_ANA_CLK_RTC_SEL_V;
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_freq == RTC_SLOW_FREQ_32K_XTAL) {
/* 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");
if (slow_clk == SLOW_CLK_32K_XTAL) {
rtc_clk_32k_enable(true);
} else if (slow_clk == SLOW_CLK_32K_EXT_OSC) {
rtc_clk_32k_enable_external();
}
// 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(RTC_CAL_32K_XTAL, SLOW_CLK_CAL_CYCLES);
if (cal_val == 0 || cal_val < MIN_32K_XTAL_CAL_VAL) {
if (retry_32k_xtal-- > 0) {
continue;
}
ESP_EARLY_LOGW(TAG, "32 kHz XTAL not found, switching to internal 150 kHz oscillator");
rtc_slow_freq = RTC_SLOW_FREQ_RTC;
}
}
} else if (rtc_slow_freq == RTC_SLOW_FREQ_8MD256) {
rtc_clk_8m_enable(true, true);
}
rtc_clk_slow_freq_set(rtc_slow_freq);
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(RTC_SLOW_FREQ_32K_XTAL);
}
/* 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)
{
uint32_t common_perip_clk, hwcrypto_perip_clk, wifi_bt_sdio_clk = 0;
uint32_t common_perip_clk1 = 0;
soc_reset_reason_t rst_reason = esp_rom_get_reset_reason(0);
/* For reason that only reset CPU, do not disable the clocks
* that have been enabled before reset.
*/
/* For reason that only reset CPU, do not disable the clocks
* that have been enabled before reset.
*/
if (rst_reason >= RESET_REASON_CPU0_MWDT0 && rst_reason <= RESET_REASON_CPU0_RTC_WDT && rst_reason != RESET_REASON_SYS_BROWN_OUT) {
common_perip_clk = ~READ_PERI_REG(SYSTEM_PERIP_CLK_EN0_REG);
hwcrypto_perip_clk = ~READ_PERI_REG(SYSTEM_PERIP_CLK_EN1_REG);
wifi_bt_sdio_clk = ~READ_PERI_REG(SYSTEM_WIFI_CLK_EN_REG);
} else {
common_perip_clk = SYSTEM_WDG_CLK_EN |
SYSTEM_I2S0_CLK_EN |
#if CONFIG_CONSOLE_UART_NUM != 0
SYSTEM_UART_CLK_EN |
#endif
#if CONFIG_CONSOLE_UART_NUM != 1
SYSTEM_UART1_CLK_EN |
#endif
SYSTEM_SPI2_CLK_EN |
SYSTEM_I2C_EXT0_CLK_EN |
SYSTEM_UHCI0_CLK_EN |
SYSTEM_RMT_CLK_EN |
SYSTEM_LEDC_CLK_EN |
SYSTEM_TIMERGROUP1_CLK_EN |
SYSTEM_SPI3_CLK_EN |
SYSTEM_SPI4_CLK_EN |
SYSTEM_TWAI_CLK_EN |
SYSTEM_I2S1_CLK_EN |
SYSTEM_SPI2_DMA_CLK_EN |
SYSTEM_SPI3_DMA_CLK_EN;
common_perip_clk1 = 0;
hwcrypto_perip_clk = SYSTEM_CRYPTO_AES_CLK_EN |
SYSTEM_CRYPTO_SHA_CLK_EN |
SYSTEM_CRYPTO_RSA_CLK_EN;
wifi_bt_sdio_clk = SYSTEM_WIFI_CLK_WIFI_EN |
SYSTEM_WIFI_CLK_BT_EN_M |
SYSTEM_WIFI_CLK_UNUSED_BIT5 |
SYSTEM_WIFI_CLK_UNUSED_BIT12;
}
//Reset the communication peripherals like I2C, SPI, UART, I2S and bring them to known state.
common_perip_clk |= SYSTEM_I2S0_CLK_EN |
#if CONFIG_CONSOLE_UART_NUM != 0
SYSTEM_UART_CLK_EN |
#endif
#if CONFIG_CONSOLE_UART_NUM != 1
SYSTEM_UART1_CLK_EN |
#endif
SYSTEM_SPI2_CLK_EN |
SYSTEM_I2C_EXT0_CLK_EN |
SYSTEM_UHCI0_CLK_EN |
SYSTEM_RMT_CLK_EN |
SYSTEM_UHCI1_CLK_EN |
SYSTEM_SPI3_CLK_EN |
SYSTEM_SPI4_CLK_EN |
SYSTEM_I2C_EXT1_CLK_EN |
SYSTEM_I2S1_CLK_EN |
SYSTEM_SPI2_DMA_CLK_EN |
SYSTEM_SPI3_DMA_CLK_EN;
common_perip_clk1 = 0;
/* Change I2S clock to audio PLL first. Because if I2S uses 160MHz clock,
* the current is not reduced when disable I2S clock.
*/
// TOCK(check replacement)
// REG_SET_FIELD(I2S_CLKM_CONF_REG(0), I2S_CLK_SEL, I2S_CLK_AUDIO_PLL);
// REG_SET_FIELD(I2S_CLKM_CONF_REG(1), I2S_CLK_SEL, I2S_CLK_AUDIO_PLL);
/* Disable some peripheral clocks. */
CLEAR_PERI_REG_MASK(SYSTEM_PERIP_CLK_EN0_REG, common_perip_clk);
SET_PERI_REG_MASK(SYSTEM_PERIP_RST_EN0_REG, common_perip_clk);
CLEAR_PERI_REG_MASK(SYSTEM_PERIP_CLK_EN1_REG, common_perip_clk1);
SET_PERI_REG_MASK(SYSTEM_PERIP_RST_EN1_REG, common_perip_clk1);
/* Disable hardware crypto clocks. */
CLEAR_PERI_REG_MASK(SYSTEM_PERIP_CLK_EN1_REG, hwcrypto_perip_clk);
SET_PERI_REG_MASK(SYSTEM_PERIP_RST_EN1_REG, hwcrypto_perip_clk);
/* Disable WiFi/BT/SDIO clocks. */
CLEAR_PERI_REG_MASK(SYSTEM_WIFI_CLK_EN_REG, wifi_bt_sdio_clk);
SET_PERI_REG_MASK(SYSTEM_WIFI_CLK_EN_REG, SYSTEM_WIFI_CLK_EN);
/* Set WiFi light sleep clock source to RTC slow clock */
REG_SET_FIELD(SYSTEM_BT_LPCK_DIV_INT_REG, SYSTEM_BT_LPCK_DIV_NUM, 0);
CLEAR_PERI_REG_MASK(SYSTEM_BT_LPCK_DIV_FRAC_REG, SYSTEM_LPCLK_SEL_8M);
SET_PERI_REG_MASK(SYSTEM_BT_LPCK_DIV_FRAC_REG, SYSTEM_LPCLK_SEL_RTC_SLOW);
/* Enable RNG clock. */
periph_module_enable(PERIPH_RNG_MODULE);
}
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