/*
* This function is not exposed as an API at this point,
* because FreeRTOS doesn't yet support dynamic changing of
* CPU frequency. Also we need to implement hooks for
* components which want to be notified of CPU frequency
* changes.
*/
void esp_clk_init(void)
{
rtc_config_t cfg = RTC_CONFIG_DEFAULT();
rtc_init(cfg);
rtc_clk_fast_freq_set(RTC_FAST_FREQ_8M);
#ifdef CONFIG_ESP32_RTC_CLOCK_SOURCE_EXTERNAL_CRYSTAL
select_rtc_slow_clk(RTC_SLOW_FREQ_32K_XTAL);
#else
select_rtc_slow_clk(RTC_SLOW_FREQ_RTC);
#endif
uint32_t freq_mhz = CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ;
rtc_cpu_freq_t freq = RTC_CPU_FREQ_80M;
switch(freq_mhz) {
case 240:
freq = RTC_CPU_FREQ_240M;
break;
case 160:
freq = RTC_CPU_FREQ_160M;
break;
default:
freq_mhz = 80;
/* no break */
case 80:
freq = RTC_CPU_FREQ_80M;
break;
}
// Wait for UART TX to finish, otherwise some UART output will be lost
// when switching APB frequency
uart_tx_wait_idle(CONFIG_CONSOLE_UART_NUM);
rtc_clk_cpu_freq_set(freq);
}
void IRAM_ATTR pm_off(void)
{
DEBUG ("%s\n", __func__);
/* suspend UARTs */
for (int i = 0; i < 3; ++i) {
REG_SET_BIT(UART_FLOW_CONF_REG(i), UART_FORCE_XOFF);
uart_tx_wait_idle(i);
}
/* set all power down flags */
uint32_t pd_flags = RTC_SLEEP_PD_DIG |
RTC_SLEEP_PD_RTC_PERIPH |
RTC_SLEEP_PD_RTC_SLOW_MEM |
RTC_SLEEP_PD_RTC_FAST_MEM |
RTC_SLEEP_PD_RTC_MEM_FOLLOW_CPU |
RTC_SLEEP_PD_VDDSDIO;
rtc_sleep_config_t config = RTC_SLEEP_CONFIG_DEFAULT(pd_flags);
config.wifi_pd_en = 1;
config.rom_mem_pd_en = 1;
config.lslp_meminf_pd = 1;
/* Save current frequency and switch to XTAL */
rtc_cpu_freq_t cpu_freq = rtc_clk_cpu_freq_get();
rtc_clk_cpu_freq_set(RTC_CPU_FREQ_XTAL);
/* set deep sleep duration to forever */
rtc_sleep_set_wakeup_time(rtc_time_get() + ~0x0UL);
/* configure deep sleep */
rtc_sleep_init(config);
rtc_sleep_start(RTC_TIMER_TRIG_EN, 0);
/* Restore CPU frequency */
rtc_clk_cpu_freq_set(cpu_freq);
/* resume UARTs */
for (int i = 0; i < 3; ++i) {
REG_CLR_BIT(UART_FLOW_CONF_REG(i), UART_FORCE_XOFF);
REG_SET_BIT(UART_FLOW_CONF_REG(i), UART_FORCE_XON);
REG_CLR_BIT(UART_FLOW_CONF_REG(i), UART_FORCE_XON);
}
}
