diagnostics/mojo/wilco_ec.mojom

// Copyright 2021 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Definitions for the event API exposed by the cros_healthd daemon. This API is
// normally consumed by the browser.

// NOTE: This mojom should be kept in sync with the copy in Chromium OS's repo
// in src/platform2/diagnostics/mojo/wilco_ec.mojom.

module chromeos.cros_healthd.mojom;

// A packet of data sent by the EC when it notices certain events have
// occurred, such as the battery, AC adapter, or USB-C state changing.
// The format of this packet is a variable length sequence of 16-bit words.
// Word 0 is the |size| word, representing the number of following
// words in the struct. Word 1 is the |type| word. The following |size|-1
// words are the |payload|. Depending on the value of |type|, the |payload|
// is interpreted in different ways. There are other possible values of |type|
// and other interpretations of |payload| than those listed here. There will
// be, at most, 6 words in the |payload|. See section 2.3 "ACPI EC Event
// notification" of the Wilco EC specification at go/wilco-ec-spec for more
// information.
struct EcEvent {
  // Derived value representing the reason/cause of the EC event.
  //
  // NOTE: This is a computed value and not sent by the EC.
  enum Reason {
    // |kSystemNotify| EC event types:
    //
    // An AC adapter event indicating a non-Wilco charger.
    kNonWilcoCharger,
    // An AC adapter event indicating a low power charger.
    kLowPowerCharger,
    // A battery event indicating an incompatible battery.
    kBatteryAuth,
    // A USB-C event indicating an HDMI conflict.
    kDockDisplay,
    // A USB-C event indicating a lack of thunderbolt support.
    kDockThunderbolt,
    // A USB-C event indicating an incompatible dock.
    kIncompatibleDock,
    // A USB-C event indicating the attached dock has overheated.
    kDockError,

    // |kSystemNotify| EC event type with no appropriate subtype.
    kSysNotification,
    // Non |kSystemNotify| EC event type.
    kNonSysNotification,
  };

  // The |type| member will be one of these.
  enum Type {
    // Interpret |payload| as a system notify payload.
    kSystemNotify = 0x0012,
  };

  Type type;
  array<uint16> payload;
  Reason reason;
};

struct GetEcTelemetryResponse {
  enum Status {
    // The EC telemetry command was successfully completed.
    kStatusOk,
    // The EC telemetry command was rejected due to the empty request payload.
    kStatusErrorInputPayloadEmpty,
    // The EC telemetry command was rejected due to the request payload being
    // too large.
    kStatusErrorInputPayloadMaxSizeExceeded,
    // The EC telemetry command was failed due to EC driver error.
    kStatusErrorAccessingDriver,
  };
  Status status;
  string payload;
};

// Implemented by clients who desire EC notifications.
interface WilcoEcObserver {
  // Fired when an EC event occurs.
  OnEcEvent(EcEvent ec_event);
};