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) 2021 Junji Sakai
   *
   * 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 "supervisor/port.h"
  #include "supervisor/board.h"
  
  #include "nrfx/hal/nrf_clock.h"
  #include "nrfx/hal/nrf_power.h"
  #include "nrfx/drivers/include/nrfx_power.h"
  #include "nrfx/drivers/include/nrfx_rtc.h"
  
  #include "nrf/cache.h"
  #include "nrf/clocks.h"
  #include "nrf/power.h"
  #include "nrf/timers.h"
  
  #include "common-hal/microcontroller/Pin.h"
  #include "common-hal/_bleio/__init__.h"
  #include "common-hal/analogio/AnalogIn.h"
  #include "common-hal/busio/I2C.h"
  #include "common-hal/busio/SPI.h"
  #include "common-hal/busio/UART.h"
  #include "common-hal/pulseio/PulseOut.h"
  #include "common-hal/pulseio/PulseIn.h"
  #include "common-hal/pwmio/PWMOut.h"
  #include "common-hal/rtc/RTC.h"
  #include "common-hal/neopixel_write/__init__.h"
  #include "common-hal/watchdog/WatchDogTimer.h"
  #include "common-hal/alarm/__init__.h"
  
  #include "shared-bindings/microcontroller/__init__.h"
  #include "shared-bindings/rtc/__init__.h"
  
  #include "lib/tinyusb/src/device/usbd.h"
  
  #ifdef CIRCUITPY_AUDIOBUSIO
  #include "common-hal/audiobusio/I2SOut.h"
  #endif
  
  #ifdef CIRCUITPY_AUDIOPWMIO
  #include "common-hal/audiopwmio/PWMAudioOut.h"
  #endif
  
  #if defined(MICROPY_QSPI_CS)
  extern void qspi_disable(void);
  #endif
  
  static void power_warning_handler(void) {
      reset_into_safe_mode(BROWNOUT);
  }
  
  uint32_t reset_reason_saved = 0;
  const nrfx_rtc_t rtc_instance = NRFX_RTC_INSTANCE(2);
  
  nrfx_rtc_config_t rtc_config = {
      .prescaler = RTC_FREQ_TO_PRESCALER(0x8000),
      .reliable = 0,
      .tick_latency = 0,
      .interrupt_priority = 6
  };
  
  #define OVERFLOW_CHECK_PREFIX 0x2cad564f
  #define OVERFLOW_CHECK_SUFFIX 0x11343ef7
  static volatile struct {
      uint32_t prefix;
      uint64_t overflowed_ticks;
      uint32_t suffix;
  } overflow_tracker __attribute__((section(".uninitialized")));
  
  void rtc_handler(nrfx_rtc_int_type_t int_type) {
      if (int_type == NRFX_RTC_INT_OVERFLOW) {
          // Our RTC is 24 bits and we're clocking it at 32.768khz which is 32 (2 ** 5) subticks per
          // tick.
          overflow_tracker.overflowed_ticks += (1L << (24 - 5));
      } else if (int_type == NRFX_RTC_INT_TICK && nrfx_rtc_counter_get(&rtc_instance) % 32 == 0) {
          // Do things common to all ports when the tick occurs
          supervisor_tick();
      } else if (int_type == NRFX_RTC_INT_COMPARE0) {
          nrfx_rtc_cc_set(&rtc_instance, 0, 0, false);
      } else if (int_type == NRFX_RTC_INT_COMPARE1) {
          // used in light sleep
          #if CIRCUITPY_ALARM
          sleepmem_wakeup_event = SLEEPMEM_WAKEUP_BY_TIMER;
          #endif
          nrfx_rtc_cc_set(&rtc_instance, 1, 0, false);
      }
  }
  
  void tick_init(void) {
      if (!nrf_clock_lf_is_running(NRF_CLOCK)) {
          nrf_clock_task_trigger(NRF_CLOCK, NRF_CLOCK_TASK_LFCLKSTART);
      }
      nrfx_rtc_counter_clear(&rtc_instance);
      nrfx_rtc_init(&rtc_instance, &rtc_config, rtc_handler);
      nrfx_rtc_enable(&rtc_instance);
      nrfx_rtc_overflow_enable(&rtc_instance, true);
  
      // If the check prefix and suffix aren't correct, then the structure
      // in memory isn't correct and the clock will be wildly wrong. Initialize
      // the prefix and suffix so that we know the value is correct, and reset
      // the time to 0.
      if (overflow_tracker.prefix != OVERFLOW_CHECK_PREFIX ||
          overflow_tracker.suffix != OVERFLOW_CHECK_SUFFIX) {
          overflow_tracker.prefix = OVERFLOW_CHECK_PREFIX;
          overflow_tracker.suffix = OVERFLOW_CHECK_SUFFIX;
          overflow_tracker.overflowed_ticks = 0;
      }
  }
  
  void tick_uninit(void) {
      nrfx_rtc_counter_clear(&rtc_instance);
      nrfx_rtc_disable(&rtc_instance);
      nrfx_rtc_uninit(&rtc_instance);
  }
  
  void tick_set_prescaler(uint32_t prescaler_val) {
      tick_uninit();
      // update of prescaler value sometimes fails if we skip this delay..
      NRFX_DELAY_US(1000);
      uint16_t prescaler_saved = rtc_config.prescaler;
      rtc_config.prescaler = prescaler_val;
      tick_init();
      rtc_config.prescaler = prescaler_saved;
  }
  
  safe_mode_t port_init(void) {
      nrf_peripherals_clocks_init();
  
      // If GPIO voltage is set wrong in UICR, this will fix it, and
      // will also do a reset to make the change take effect.
      nrf_peripherals_power_init();
  
      nrfx_power_pofwarn_config_t power_failure_config;
      power_failure_config.handler = power_warning_handler;
      power_failure_config.thr = NRF_POWER_POFTHR_V27;
      #if NRF_POWER_HAS_VDDH
      power_failure_config.thrvddh = NRF_POWER_POFTHRVDDH_V27;
      #endif
      nrfx_power_pof_init(&power_failure_config);
      nrfx_power_pof_enable(&power_failure_config);
  
      nrf_peripherals_enable_cache();
  
      // Configure millisecond timer initialization.
      tick_init();
  
      #if CIRCUITPY_RTC
      common_hal_rtc_init();
      #endif
  
      #if CIRCUITPY_ANALOGIO
      analogin_init();
      #endif
  
      reset_reason_saved = NRF_POWER->RESETREAS;
      // clear all RESET reason bits
      NRF_POWER->RESETREAS = reset_reason_saved;
      // clear wakeup event/pin when reset by reset-pin
      if (reset_reason_saved & NRF_POWER_RESETREAS_RESETPIN_MASK) {
          #if CIRCUITPY_ALARM
          sleepmem_wakeup_event = SLEEPMEM_WAKEUP_BY_NONE;
          #endif
      }
  
      // If the board was reset by the WatchDogTimer, we may
      // need to boot into safe mode. Reset the RESETREAS bit
      // for the WatchDogTimer so we don't encounter this the
      // next time we reboot.
      if (reset_reason_saved & POWER_RESETREAS_DOG_Msk) {
          NRF_POWER->RESETREAS = POWER_RESETREAS_DOG_Msk;
          uint32_t usb_reg = NRF_POWER->USBREGSTATUS;
  
          // If USB is connected, then the user might be editing `code.py`,
          // in which case we should reboot into Safe Mode.
          if (usb_reg & POWER_USBREGSTATUS_VBUSDETECT_Msk) {
              return WATCHDOG_RESET;
          }
      }
  
      return NO_SAFE_MODE;
  }
  
  void reset_port(void) {
      #if CIRCUITPY_BUSIO
      i2c_reset();
      spi_reset();
      uart_reset();
      #endif
  
      #if CIRCUITPY_NEOPIXEL_WRITE
      neopixel_write_reset();
      #endif
  
      #if CIRCUITPY_AUDIOBUSIO
      i2s_reset();
      #endif
  
      #if CIRCUITPY_AUDIOPWMIO
      audiopwmout_reset();
      #endif
  
  
      #if CIRCUITPY_PULSEIO
      pulseout_reset();
      pulsein_reset();
      #endif
  
      #if CIRCUITPY_PWMIO
      pwmout_reset();
      #endif
  
      #if CIRCUITPY_RTC
      rtc_reset();
      #endif
  
      timers_reset();
  
      #if CIRCUITPY_BLEIO
      bleio_reset();
      #endif
  
      #if CIRCUITPY_WATCHDOG
      watchdog_reset();
      #endif
  
      reset_all_pins();
  }
  
  void reset_to_bootloader(void) {
      enum { DFU_MAGIC_SERIAL = 0x4e };
  
      NRF_POWER->GPREGRET = DFU_MAGIC_SERIAL;
      reset_cpu();
  }
  
  void reset_cpu(void) {
      // We're getting ready to reset, so save the counter off.
      // This counter will get reset to zero during the reboot.
      uint32_t ticks = nrfx_rtc_counter_get(&rtc_instance);
      overflow_tracker.overflowed_ticks += ticks / 32;
      NVIC_SystemReset();
      for (;;) {
      }
  }
  
  // The uninitialized data section is placed directly after BSS, under the theory
  // that CircuitPython has a lot more .data and .bss than the bootloader.  As a
  // result, this section is less likely to be tampered with by the bootloader.
  extern uint32_t _euninitialized;
  
  uint32_t *port_heap_get_bottom(void) {
      return &_euninitialized;
  }
  
  uint32_t *port_heap_get_top(void) {
      return port_stack_get_top();
  }
  
  bool port_has_fixed_stack(void) {
      return false;
  }
  
  uint32_t *port_stack_get_limit(void) {
      return &_euninitialized;
  }
  
  uint32_t *port_stack_get_top(void) {
      return &_estack;
  }
  
  // Place the word in the uninitialized section so it won't get overwritten.
  __attribute__((section(".uninitialized"))) uint32_t _saved_word;
  void port_set_saved_word(uint32_t value) {
      _saved_word = value;
  }
  
  uint32_t port_get_saved_word(void) {
      return _saved_word;
  }
  
  uint64_t port_get_raw_ticks(uint8_t *subticks) {
      common_hal_mcu_disable_interrupts();
      uint32_t rtc = nrfx_rtc_counter_get(&rtc_instance);
      uint64_t overflow_count = overflow_tracker.overflowed_ticks;
      common_hal_mcu_enable_interrupts();
  
      if (subticks != NULL) {
          *subticks = (rtc % 32);
      }
      return overflow_count + rtc / 32;
  }
  
  // Enable 1/1024 second tick.
  void port_enable_tick(void) {
      nrfx_rtc_tick_enable(&rtc_instance, true);
  }
  
  // Disable 1/1024 second tick.
  void port_disable_tick(void) {
      nrfx_rtc_tick_disable(&rtc_instance);
  }
  
  void port_interrupt_after_ticks_ch(uint32_t channel, uint32_t ticks) {
      uint32_t current_ticks = nrfx_rtc_counter_get(&rtc_instance);
      uint32_t diff = 3;
      if (ticks > diff) {
          diff = ticks * 32;
      }
      if (diff > 0xffffff) {
          diff = 0xffffff;
      }
      nrfx_rtc_cc_set(&rtc_instance, channel, current_ticks + diff, true);
  }
  
  void port_disable_interrupt_after_ticks_ch(uint32_t channel) {
      nrfx_rtc_cc_disable(&rtc_instance, channel);
  }
  
  void port_interrupt_after_ticks(uint32_t ticks) {
      port_interrupt_after_ticks_ch(0, ticks);
  }
  
  void port_idle_until_interrupt(void) {
      #if defined(MICROPY_QSPI_CS)
      qspi_disable();
      #endif
  
      // Clear the FPU interrupt because it can prevent us from sleeping.
      if (NVIC_GetPendingIRQ(FPU_IRQn)) {
          __set_FPSCR(__get_FPSCR() & ~(0x9f));
          (void)__get_FPSCR();
          NVIC_ClearPendingIRQ(FPU_IRQn);
      }
      uint8_t sd_enabled;
  
      sd_softdevice_is_enabled(&sd_enabled);
      if (sd_enabled) {
          sd_app_evt_wait();
      } else {
          // Call wait for interrupt ourselves if the SD isn't enabled.
          // Note that `wfi` should be called with interrupts disabled,
          // to ensure that the queue is properly drained.  The `wfi`
          // instruction will returned as long as an interrupt is
          // available, even though the actual handler won't fire until
          // we re-enable interrupts.
          //
          // We do not use common_hal_mcu_disable_interrupts here because
          // we truly require that interrupts be disabled, while
          // common_hal_mcu_disable_interrupts actually just masks the
          // interrupts that are not required to allow the softdevice to
          // function (whether or not SD is enabled)
          int nested = __get_PRIMASK();
          __disable_irq();
          bool ok = true;
          #if CIRCUITPY_USB
          ok = !tud_task_event_ready();
          #endif
          if (ok) {
              __DSB();
              __WFI();
          }
          if (!nested) {
              __enable_irq();
          }
      }
  }
  
  
  void HardFault_Handler(void) {
      reset_into_safe_mode(HARD_CRASH);
      while (true) {
          asm ("nop;");
      }
  }
  
  #if CIRCUITPY_ALARM
  // in case boards/xxx/board.c does not provide board_deinit()
  MP_WEAK void board_deinit(void) {
  }
  #endif
  