deep sleep: bring some registers into known state

In case WiFi/BT stack has been enabled but wasn’t disabled, some RTC
bits may be left enabled, causing increased current consumption.
This change returns some of the bits back to their default values.

diff --git a/components/esp32/deep_sleep.c b/components/esp32/deep_sleep.c
index 3eef7ca29d0fce327cd0495d290bf07715a7245e..4d672402e1ab97c747256d9b2f0252b6be75ac16 100644 (file)
--- a/components/esp32/deep_sleep.c
+++ b/components/esp32/deep_sleep.c
@@ -22,6 +22,7 @@
 #include "rom/uart.h"
 #include "soc/cpu.h"
 #include "soc/rtc_cntl_reg.h"
+#include "soc/sens_reg.h"
 #include "soc/dport_reg.h"
 #include "driver/rtc_io.h"
 #include "freertos/FreeRTOS.h"
@@ -111,6 +112,13 @@ void IRAM_ATTR esp_deep_sleep_start()
     // Decide which power domains can be powered down
     uint32_t pd_flags = get_power_down_flags();
 
+    // Shut down parts of RTC which may have been left enabled by the wireless drivers
+    CLEAR_PERI_REG_MASK(RTC_CNTL_ANA_CONF_REG,
+            RTC_CNTL_CKGEN_I2C_PU | RTC_CNTL_PLL_I2C_PU |
+            RTC_CNTL_RFRX_PBUS_PU | RTC_CNTL_TXRF_I2C_PU);
+
+    SET_PERI_REG_BITS(SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_SAR_M, 0, SENS_FORCE_XPD_SAR_S);
+
     // Configure pins for external wakeup
     if (s_config.wakeup_triggers & EXT_EVENT0_TRIG_EN) {
         ext0_wakeup_prepare();