automotive/can/1.0/types.hal

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package android.hardware.automotive.can@1.0;

/**
 * CAN message ID.
 *
 * Does not include any flags like RTR nor ERR, only a plain 11-bit
 * or 29-bit identifier, as defined in CAN 1.x/2.0x.
 *
 * Unused bits must be set to zero.
 */
typedef uint32_t CanMessageId;

/**
 * CAN message being sent or received.
 */
struct CanMessage {
    CanMessageId id;

    /**
     * CAN message payload, as defined in CAN 1.x and CAN 2.x standards.
     *
     * The length of the payload vector directly translates to the length
     * of the data frame (i.e. includes any padding bytes), so it may be in
     * a range of:
     *  - 0-8 bytes for standard CAN;
     *  - up to 64 bytes for CAN FD.
     * ISO TP is not supported directly for now.
     */
    vec<uint8_t> payload;

    /**
     * Time in nanoseconds since boot.
     *
     * Ignored for outgoing messages.
     */
    uint64_t timestamp;

    /**
     * A request to proactively pull certain data from other ECU in CAN network.
     *
     * For details please refer to CAN standard.
     *
     * If this flag is set, payload must be empty.
     */
    bool remoteTransmissionRequest;
};

/**
 * Single filter rule for CAN messages.
 *
 * A filter is satisfied if:
 * ((receivedId & mask) == (id & mask)) == !inverted
 *
 * In order for set of filters to match, at least one non-inverted filters must match (if there is
 * one) and all inverted filters must match. In other words:
 *  - a single matching non-inverted filter makes the whole set matching;
 *  - a single non-matching inverted filter makes the whole set non-matching.
 */
struct CanMessageFilter {
    CanMessageId id;
    uint32_t mask;
    bool inverted;
};

enum Result : uint8_t {
    OK,
    UNKNOWN_ERROR,
    PAYLOAD_TOO_LONG,
    INTERFACE_DOWN,
    TRANSMISSION_FAILURE,
    INVALID_ARGUMENTS,
};

/**
 * @see ICanMessageListener#onError
 */
enum ErrorEvent : uint8_t {
    UNKNOWN_ERROR,

    /** A problem with CAN interface HW. */
    HARDWARE_ERROR,

    /** TX buffer overflow: client is sending too many packets. */
    TX_OVERFLOW,

    /** RX buffer overflow: client is not reading packets fast enough. */
    RX_OVERFLOW,

    /** Received malformed input. */
    MALFORMED_INPUT,

    /** Bus overload: there is too much traffic on the bus. */
    BUS_OVERLOAD,

    /** Bus error: shorted Hi/Lo line, bus off etc. */
    BUS_ERROR,
};