power_saving.h

// WARNING: To stay in compliance with the SIL2 rules laid out in STM UM1840, we should never implement any of the available hardware low power modes.
// See rule: CoU_3

#define POWER_SAVE_STATUS_DISABLED 0
#define POWER_SAVE_STATUS_ENABLED 1

int power_save_status = POWER_SAVE_STATUS_DISABLED;

void set_power_save_state(int state) {

  bool is_valid_state = (state == POWER_SAVE_STATUS_ENABLED) || (state == POWER_SAVE_STATUS_DISABLED);
  if (is_valid_state && (state != power_save_status)) {
    bool enable = false;
    if (state == POWER_SAVE_STATUS_ENABLED) {
      print("enable power savings\n");
      if (current_board->has_gps) {
        const char UBLOX_SLEEP_MSG[] = "\xb5\x62\x06\x04\x04\x00\x01\x00\x08\x00\x17\x78";
        uart_ring *ur = get_ring_by_number(1);
        for (unsigned int i = 0; i < sizeof(UBLOX_SLEEP_MSG) - 1U; i++) while (!putc(ur, UBLOX_SLEEP_MSG[i]));
      }
      // Disable CAN interrupts
      if (harness.status == HARNESS_STATUS_FLIPPED) {
        llcan_irq_disable(cans[0]);
      } else {
        llcan_irq_disable(cans[2]);
      }
      llcan_irq_disable(cans[1]);
    } else {
      print("disable power savings\n");
      if (current_board->has_gps) {
        const char UBLOX_WAKE_MSG[] = "\xb5\x62\x06\x04\x04\x00\x01\x00\x09\x00\x18\x7a";
        uart_ring *ur = get_ring_by_number(1);
        for (unsigned int i = 0; i < sizeof(UBLOX_WAKE_MSG) - 1U; i++) while (!putc(ur, UBLOX_WAKE_MSG[i]));
      }

      if (harness.status == HARNESS_STATUS_FLIPPED) {
        llcan_irq_enable(cans[0]);
      } else {
        llcan_irq_enable(cans[2]);
      }
      llcan_irq_enable(cans[1]);

      enable = true;
    }

    current_board->enable_can_transceivers(enable);

    // Switch EPS/GPS
    if (enable) {
      current_board->set_gps_mode(GPS_ENABLED);
    } else {
      current_board->set_gps_mode(GPS_DISABLED);
    }

    if(current_board->has_hw_gmlan){
      // turn on GMLAN
      set_gpio_output(GPIOB, 14, enable);
      set_gpio_output(GPIOB, 15, enable);
    }

    if(current_board->has_lin){
      // turn on LIN
      set_gpio_output(GPIOB, 7, enable);
      set_gpio_output(GPIOA, 14, enable);
    }

    // Switch off IR when in power saving
    if(!enable){
      current_board->set_ir_power(0U);
    }

    power_save_status = state;
  }
}