DRAFT: Use automatic light sleep for ESP32 alarm sleep

ports/espressif/common-hal/alarm/__init__.c

@@ -4,11 +4,12 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Dan Halbert for Adafruit Industries
 //
 // SPDX-License-Identifier: MIT
-
+#include <stdio.h>
 #include "py/gc.h"
 #include "py/obj.h"
 #include "py/objtuple.h"
 #include "py/runtime.h"
+#include "py/mpprint.h"
 
 #include "shared-bindings/alarm/__init__.h"
 #include "shared-bindings/alarm/SleepMemory.h"
@@ -27,8 +28,10 @@
 
 #include "supervisor/port.h"
 #include "supervisor/shared/workflow.h"
+#include "supervisor/shared/serial.h"
 
 #include "esp_sleep.h"
+#include "esp_pm.h"
 
 #include "driver/gpio.h"
 #include "driver/uart.h"
@@ -139,6 +142,27 @@ mp_obj_t common_hal_alarm_light_sleep_until_alarms(size_t n_alarms, const mp_obj
 
     mp_obj_t wake_alarm = mp_const_none;
 
+    bool use_real_sleep = !serial_connected();
+
+
+    #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
+    esp_pm_config_t old_pm;
+    esp_pm_get_configuration(&old_pm);
+
+    esp_pm_config_t pm;
+    esp_pm_get_configuration(&pm);
+
+    pm.max_freq_mhz = 240;
+    pm.min_freq_mhz = 80;
+
+    if (use_real_sleep) {
+        pm.light_sleep_enable = true;
+    }
+
+    ESP_ERROR_CHECK_WITHOUT_ABORT(esp_pm_configure(&pm));
+    #endif
+
+
     // We cannot esp_light_sleep_start() here because it shuts down all non-RTC peripherals.
     while (!mp_hal_is_interrupted()) {
         RUN_BACKGROUND_TASKS;
@@ -176,6 +200,11 @@ mp_obj_t common_hal_alarm_light_sleep_until_alarms(size_t n_alarms, const mp_obj
         port_idle_until_interrupt();
     }
 
+    #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
+    esp_pm_configure(&old_pm);
+    #endif
+
+
     if (mp_hal_is_interrupted()) {
         return mp_const_none; // Shouldn't be given to python code because exception handling should kick in.
     }

ports/espressif/common-hal/busio/UART.c

@@ -19,6 +19,7 @@
 #include "py/stream.h"
 #include "supervisor/port.h"
 #include "supervisor/shared/tick.h"
+#include "esp_sleep.h"
 
 static uint8_t never_reset_uart_mask = 0;
 
@@ -215,7 +216,8 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     if (uart_param_config(self->uart_num, &uart_config) != ESP_OK) {
         mp_raise_RuntimeError(MP_ERROR_TEXT("UART init"));
     }
-
+    uart_set_wakeup_threshold(self->uart_num, 1);
+    esp_sleep_enable_uart_wakeup(self->uart_num);
     self->tx_pin = NULL;
     self->rx_pin = NULL;
     self->rts_pin = NULL;

ports/espressif/esp-idf-config/sdkconfig.defaults

@@ -32,7 +32,7 @@ CONFIG_GPTIMER_ISR_IRAM_SAFE=y
 # Power Management
 #
 CONFIG_PM_ENABLE=y # required for CIRCUITPY_SETTABLE_PROCESSOR_FREQUENCY
-
+CONFIG_PM_PROFILING=y
 #
 # ESP System Settings
 #
@@ -56,6 +56,7 @@ CONFIG_ESP_MAIN_TASK_STACK_SIZE=16384
 # Kernel
 #
 CONFIG_FREERTOS_HZ=1000
+CONFIG_FREERTOS_USE_TICKLESS_IDLE=y
 # end of Kernel
 
 #

ports/espressif/supervisor/port.c

@@ -208,6 +208,7 @@ safe_mode_t port_init(void) {
     args.arg = NULL;
     args.dispatch_method = ESP_TIMER_TASK;
     args.name = "CircuitPython Tick";
+    args.skip_unhandled_events = true;
     esp_timer_create(&args, &_tick_timer);
 
     args.callback = &sleep_timer_cb;

supervisor/shared/serial.c

@@ -13,6 +13,7 @@
 #include "supervisor/shared/cpu.h"
 #include "supervisor/shared/display.h"
 #include "shared-bindings/terminalio/Terminal.h"
+#include "supervisor/port.h"
 #include "supervisor/shared/serial.h"
 #include "shared-bindings/microcontroller/Pin.h"
 
@@ -46,6 +47,10 @@ byte console_uart_rx_buf[64];
 #endif
 #endif
 
+#if CIRCUITPY_CONSOLE_UART
+static uint64_t _console_uart_rx_timestamp = 0;
+#endif
+
 #if CIRCUITPY_USB_DEVICE || CIRCUITPY_CONSOLE_UART
 // Flag to note whether this is the first write after connection.
 // Delay slightly on the first write to allow time for the host to set up things,
@@ -175,7 +180,9 @@ bool serial_connected(void) {
     #endif
 
     #if CIRCUITPY_CONSOLE_UART
-    return true;
+    if (_console_uart_rx_timestamp && (_console_uart_rx_timestamp + (60 * 1024 * 5) > port_get_raw_ticks(NULL))) {
+        return true;
+    }
     #endif
 
     #if CIRCUITPY_SERIAL_BLE
@@ -232,6 +239,7 @@ char serial_read(void) {
         int uart_errcode;
         char text;
         common_hal_busio_uart_read(&console_uart, (uint8_t *)&text, 1, &uart_errcode);
+        _console_uart_rx_timestamp = port_get_raw_ticks(NULL);
         return text;
     }
     #endif