src/devices/board/drivers/x86/power.cc

// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "power.h"

#include <lib/ddk/debug.h>
#include <zircon/syscalls/system.h>

#include <acpica/acpi.h>

// TODO(https://fxbug.dev/317387259): change name to acpi_power_resource to be more
// accurate.
zx_handle_t acpi_root_resource;

void poweroff(zx_device_t* device) {
  acpi_root_resource = power_resource_handle;
  ACPI_STATUS status = AcpiEnterSleepStatePrep(5);
  if (status == AE_OK) {
    // AcpiEnterSleepState is usually called with interrupts disabled so that the interrupt state
    // can be saved and restored on wake. However for power off (sleep state 5) AcpiEnterSleepState
    // can be called without interrupts disabled as caches are dropped regardless.
    AcpiEnterSleepState(5);
  }
}

zx_status_t suspend_to_ram(zx_device_t* device) {
  acpi_root_resource = power_resource_handle;
  zx_status_t status = ZX_OK;

  acpica_enable_noncontested_mode();

  status = zx_system_powerctl(power_resource_handle,
                              ZX_SYSTEM_POWERCTL_DISABLE_ALL_CPUS_BUT_PRIMARY, nullptr);
  if (status != ZX_OK) {
    zxlogf(ERROR, "acpi: Failed to shutdown CPUs: %d", status);
    goto cleanup;
  }

  ACPI_STATUS acpi_status;
  acpi_status = AcpiEnterSleepStatePrep(3);
  if (acpi_status != AE_OK) {
    zxlogf(ERROR, "acpi: Failed to prep enter sleep state: %x", acpi_status);
    // TODO: I think we need to do LeaveSleepState{Prep,} on failure
    status = ZX_ERR_INTERNAL;
    goto cleanup;
  }

  acpi_status = AcpiEnterSleepState(3);
  if (acpi_status != AE_OK) {
    status = ZX_ERR_INTERNAL;
    zxlogf(ERROR, "acpi: Failed to enter sleep state: %x", acpi_status);
    // Continue executing to try to get the system back to where it was
  }
  zxlogf(DEBUG, "acpi: Woke up from sleep");

  acpi_status = AcpiLeaveSleepStatePrep(3);
  if (acpi_status != AE_OK) {
    status = ZX_ERR_INTERNAL;
    zxlogf(ERROR, "acpi: Failed to prep leave sleep state: %x", acpi_status);
  }

  acpi_status = AcpiLeaveSleepState(3);
  if (acpi_status != AE_OK) {
    status = ZX_ERR_INTERNAL;
    zxlogf(ERROR, "acpi: Failed to leave sleep state: %x", acpi_status);
  }

cleanup:
  zx_status_t status2;
  status2 = zx_system_powerctl(power_resource_handle, ZX_SYSTEM_POWERCTL_ENABLE_ALL_CPUS, nullptr);
  if (status2 != ZX_OK) {
    zxlogf(ERROR, "acpi: Re-enabling all cpus failed: %d", status2);
  }

  acpica_disable_noncontested_mode();

  zxlogf(INFO, "acpi: Finished processing suspend: %d", status);
  return status;
}