text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
   * Copyright (c) 2019 Lucian Copeland for Adafruit Industries
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdint.h>
  #include <sys/time.h>
  #include "supervisor/port.h"
  #include "boards/board.h"
  #include "modules/module.h"
  
  #include "freertos/FreeRTOS.h"
  #include "freertos/task.h"
  
  #include "common-hal/microcontroller/Pin.h"
  #include "common-hal/busio/I2C.h"
  #include "common-hal/busio/SPI.h"
  #include "common-hal/busio/UART.h"
  #include "supervisor/memory.h"
  #include "supervisor/shared/tick.h"
  
  STATIC esp_timer_handle_t _tick_timer;
  
  void tick_timer_cb(void* arg) {
      supervisor_tick();
  }
  
  safe_mode_t port_init(void) {
      esp_timer_create_args_t args;
      args.callback = &tick_timer_cb;
      args.arg = NULL;
      args.dispatch_method = ESP_TIMER_TASK;
      args.name = "CircuitPython Tick";
      esp_timer_create(&args, &_tick_timer);
      never_reset_module_internal_pins();
      return NO_SAFE_MODE;
  }
  
  void reset_port(void) {
      reset_all_pins();
  
      // A larger delay so the idle task can run and do any IDF cleanup needed.
      vTaskDelay(4);
  
  #if CIRCUITPY_BUSIO
      i2c_reset();
      spi_reset();
      uart_reset();
  #endif
  }
  
  void reset_to_bootloader(void) {
  }
  
  void reset_cpu(void) {
  }
  
  uint32_t heap[64 / sizeof(uint32_t) * 1024];
  
  uint32_t *port_heap_get_bottom(void) {
      return heap;
  }
  
  uint32_t *port_heap_get_top(void) {
      return heap + sizeof(heap) / sizeof(heap[0]);
  }
  
  uint32_t *port_stack_get_limit(void) {
      #pragma GCC diagnostic push
      #pragma GCC diagnostic ignored "-Wcast-align"
      return (uint32_t*) pxTaskGetStackStart(NULL);
      #pragma GCC diagnostic pop
  }
  
  uint32_t *port_stack_get_top(void) {
      return port_stack_get_limit() + CONFIG_ESP_MAIN_TASK_STACK_SIZE / (sizeof(uint32_t) / sizeof(StackType_t));
  }
  
  supervisor_allocation _fixed_stack;
  
  supervisor_allocation* port_fixed_stack(void) {
      _fixed_stack.ptr = port_stack_get_limit();
      _fixed_stack.length = (port_stack_get_top() - port_stack_get_limit()) * sizeof(uint32_t);
      return &_fixed_stack;
  }
  
  // Place the word to save just after our BSS section that gets blanked.
  void port_set_saved_word(uint32_t value) {
  }
  
  uint32_t port_get_saved_word(void) {
      return 0;
  }
  
  uint64_t port_get_raw_ticks(uint8_t* subticks) {
      struct timeval tv_now;
      gettimeofday(&tv_now, NULL);
      // convert usec back to ticks
      uint64_t all_subticks = (uint64_t)(tv_now.tv_usec * 2) / 71;
      if (subticks != NULL) {
          *subticks = all_subticks % 32;
      }
      return (uint64_t)tv_now.tv_sec * 1024L + all_subticks / 32;
  }
  
  // Enable 1/1024 second tick.
  void port_enable_tick(void) {
      esp_timer_start_periodic(_tick_timer, 1000000 / 1024);
  }
  
  // Disable 1/1024 second tick.
  void port_disable_tick(void) {
      esp_timer_stop(_tick_timer);
  }
  
  TickType_t sleep_time_set;
  TickType_t sleep_time_duration;
  void port_interrupt_after_ticks(uint32_t ticks) {
      sleep_time_set = xTaskGetTickCount();
      sleep_time_duration = ticks / portTICK_PERIOD_MS;
      // esp_sleep_enable_timer_wakeup(uint64_t time_in_us)
  }
  
  void port_sleep_until_interrupt(void) {
      // FreeRTOS delay here maybe.
      // Light sleep shuts down BLE and wifi.
      // esp_light_sleep_start()
      if (sleep_time_duration == 0) {
          return;
      }
      vTaskDelayUntil(&sleep_time_set, sleep_time_duration);
  }
  
  
  // Wrap main in app_main that the IDF expects.
  extern void main(void);
  void app_main(void) {
      main();
  }
  