driver/src/backlight_manager.cc

// Copyright 2022 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 "driver/src/backlight_manager.h"

#include <lib/driver/logging/cpp/structured_logger.h>

namespace backlight_driver {
zx::result<> BacklightManager::SetBacklight(uint64_t value) {
  fidl::Arena arena;
  auto input = fuchsia_hardware_acpi::wire::Object::WithIntegerVal(arena, value);

  auto result = acpi_device_client_->EvaluateObject(
      fidl::StringView::FromExternal(kLedWrite),
      fuchsia_hardware_acpi::EvaluateObjectMode::kPlainObject,
      fidl::VectorView<fuchsia_hardware_acpi::wire::Object>::FromExternal(&input, 1));

  if (!result.ok()) {
    return zx::error(result.status());
  }

  if (result->is_error()) {
    FDF_SLOG(ERROR, "EvaluateObject error.",
             KV("acpi_status", fidl::ToUnderlying(result->error_value())));
    return zx::error(ZX_ERR_INTERNAL);
  }

  return zx::ok();
}

zx::result<uint64_t> BacklightManager::GetBacklight() {
  auto result =
      acpi_device_client_->EvaluateObject(fidl::StringView::FromExternal(kLedRead),
                                          fuchsia_hardware_acpi::EvaluateObjectMode::kPlainObject,
                                          fidl::VectorView<fuchsia_hardware_acpi::wire::Object>());

  if (!result.ok()) {
    return zx::error(result.status());
  }

  if (result->is_error()) {
    FDF_SLOG(ERROR, "EvaluateObject error.",
             KV("acpi_status", fidl::ToUnderlying(result->error_value())));
    return zx::error(ZX_ERR_INTERNAL);
  }

  fuchsia_hardware_acpi::wire::DeviceEvaluateObjectResponse& backlight = *result->value();
  if (!backlight.result.has_value()) {
    return zx::error(ZX_ERR_INVALID_ARGS);
  }
  fuchsia_hardware_acpi::wire::EncodedObject& encoded = backlight.result.value();
  if (!encoded.is_object()) {
    return zx::error(ZX_ERR_INVALID_ARGS);
  }
  if (!encoded.object().is_integer_val()) {
    return zx::error(ZX_ERR_INVALID_ARGS);
  }

  return zx::ok(encoded.object().integer_val());
}
}  // namespace backlight_driver