driver/src/backlight_driver.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_driver.h"

#include <fidl/fuchsia.hardware.acpi/cpp/wire.h>
#include <lib/async/cpp/task.h>
#include <lib/zx/clock.h>

namespace backlight_driver {

// Public methods.
zx::result<> BacklightDriver::Start() {
  auto init_result = Initialize();
  if (init_result.is_error()) {
    FDF_SLOG(ERROR, "Failed to initialize.", KV("status", init_result.status_string()));
    return init_result.take_error();
  }

  auto set_result = backlight_manager_->SetBacklight(kMaxBacklight);
  if (set_result.is_error()) {
    FDF_SLOG(ERROR, "Failed to set backlight.", KV("status", set_result.status_string()));
    return set_result.take_error();
  }

  auto get_result = backlight_manager_->GetBacklight();
  if (get_result.is_error()) {
    FDF_SLOG(ERROR, "Failed to get backlight.", KV("status", get_result.status_string()));
    return get_result.take_error();
  }

  // Starts a breathing animation on the keyboard.
  StartBacklightBreathing();
  FDF_LOG(INFO, "Keyboard backlight driver started.");
  return zx::ok();
}

// Private methods.
zx::result<> BacklightDriver::Initialize() {
  // Connect to parent.
  auto connect_result = context().incoming()->Connect<fuchsia_hardware_acpi::Service::Device>();
  if (!connect_result.is_ok()) {
    return connect_result.take_error();
  }

  backlight_manager_.emplace(&logger(), std::move(connect_result.value()));
  return zx::ok();
}

void BacklightDriver::StartBacklightBreathing() {
  breathing_start = zx::clock::get_monotonic();
  BreathingBacklightImpl(0);
}

void BacklightDriver::BreathingBacklightImpl(int next_index) {
  if (zx::clock::get_monotonic() - breathing_start > kAnimationDuration) {
    FDF_LOG(INFO, "Stopping breathing animation and setting backlight to maximum.");
    auto set_result = backlight_manager_->SetBacklight(kMaxBacklight);
    if (set_result.is_error()) {
      FDF_SLOG(ERROR, "Failed to set backlight to max after breathing animation completion.",
               KV("status", set_result.status_string()));
    }

    return;
  }

  uint64_t next_value = kAnimation[next_index];
  std::ignore = backlight_manager_->SetBacklight(next_value);
  async::PostDelayedTask(
      dispatcher(),
      [this, next_index, vals = kAnimation.size()]() mutable {
        BreathingBacklightImpl((next_index + 1) % vals);
      },
      kAnimationInterval);
}

}  // namespace backlight_driver

FUCHSIA_DRIVER_LIFECYCLE_CPP_V3(fdf::Lifecycle<backlight_driver::BacklightDriver>);