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Diffstat (limited to 'can-utils.h')
| -rw-r--r-- | can-utils.h | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/can-utils.h b/can-utils.h new file mode 100644 index 00000000..7d00dd1a --- /dev/null +++ b/can-utils.h @@ -0,0 +1,328 @@ + +/* + * Copyright (C) 2015, 2016 "IoT.bzh" + * Author "Romain Forlot" <romain.forlot@iot.bzh> + * + * 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. + */ + +#pragma once + +#include "timer.h" +#include "openxc.pb.h" + +// TODO actual max is 32 but dropped to 24 for memory considerations +#define MAX_ACCEPTANCE_FILTERS 24 +// TODO this takes up a ton of memory +#define MAX_DYNAMIC_MESSAGE_COUNT 12 + +#define CAN_MESSAGE_SIZE 8 + +#define CAN_ACTIVE_TIMEOUT_S 30 + +#define QUEUE_DECLARE(type, max_length) \ +static const int queue_##type##_max_length = max_length; \ +static const int queue_##type##_max_internal_length = max_length + 1; \ +typedef struct queue_##type##_s { \ + int head; \ + int tail; \ + type elements[max_length + 1]; \ +} queue_##type; \ +\ +bool queue_##type##_push(queue_##type* queue, type value); \ +\ +type queue_##type##_pop(queue_##type* queue); \ +\ +type queue_##type##_peek(queue_##type* queue); \ +void queue_##type##_init(queue_##type* queue); \ +int queue_##type##_length(queue_##type* queue); \ +int queue_##type##_available(queue_##type* queue); \ +bool queue_##type##_full(queue_##type* queue); \ +bool queue_##type##_empty(queue_##type* queue); \ +void queue_##type##_snapshot(queue_##type* queue, type* snapshot, int max); + +/* Public: The type signature for a CAN signal decoder. + * + * A SignalDecoder transforms a raw floating point CAN signal into a number, + * string or boolean. + * + * signal - The CAN signal that we are decoding. + * signals - The list of all signals. + * signalCount - The length of the signals array. + * pipeline - you may want to generate arbitrary additional messages for + * publishing. + * value - The CAN signal parsed from the message as a raw floating point + * value. + * send - An output parameter. If the decoding failed or the CAN signal should + * not send for some other reason, this should be flipped to false. + * + * Returns a decoded value in an openxc_DynamicField struct. + */ +typedef openxc_DynamicField (*SignalDecoder)(struct CanSignal* signal, + CanSignal* signals, int signalCount, + openxc::pipeline::Pipeline* pipeline, float value, bool* send); + +/* Public: The type signature for a CAN signal encoder. + * + * A SignalEncoder transforms a number, string or boolean into a raw floating + * point value that fits in the CAN signal. + * + * signal - The CAN signal to encode. + * value - The dynamic field to encode. + * send - An output parameter. If the encoding failed or the CAN signal should + * not be encoded for some other reason, this will be flipped to false. + */ +typedef uint64_t (*SignalEncoder)(struct CanSignal* signal, + openxc_DynamicField* value, bool* send); + +/* Public: The ID format for a CAN message. + * + * STANDARD - standard 11-bit CAN arbitration ID. + * EXTENDED - an extended frame, with a 29-bit arbitration ID. + */ +enum CanMessageFormat { + STANDARD, + EXTENDED, +}; +typedef enum CanMessageFormat CanMessageFormat; + +/* Public: A state encoded (SED) signal's mapping from numerical values to + * OpenXC state names. + * + * value - The integer value of the state on the CAN bus. + * name - The corresponding string name for the state in OpenXC. + */ +struct CanSignalState { + const int value; + const char* name; +}; +typedef struct CanSignalState CanSignalState; + +/* Public: A CAN signal to decode from the bus and output over USB. + * + * message - The message this signal is a part of. + * genericName - The name of the signal to be output over USB. + * bitPosition - The starting bit of the signal in its CAN message (assuming + * non-inverted bit numbering, i.e. the most significant bit of + * each byte is 0) + * bitSize - The width of the bit field in the CAN message. + * factor - The final value will be multiplied by this factor. Use 1 if you + * don't need a factor. + * offset - The final value will be added to this offset. Use 0 if you + * don't need an offset. + * minValue - The minimum value for the processed signal. + * maxValue - The maximum value for the processed signal. + * frequencyClock - A FrequencyClock struct to control the maximum frequency to + * process and send this signal. To process every value, set the + * clock's frequency to 0. + * sendSame - If true, will re-send even if the value hasn't changed. + * forceSendChanged - If true, regardless of the frequency, it will send the + * value if it has changed. + * states - An array of CanSignalState describing the mapping + * between numerical and string values for valid states. + * stateCount - The length of the states array. + * writable - True if the signal is allowed to be written from the USB host + * back to CAN. Defaults to false. + * decoder - An optional function to decode a signal from the bus to a human + * readable value. If NULL, the default numerical decoder is used. + * encoder - An optional function to encode a signal value to be written to + * CAN into a byte array. If NULL, the default numerical encoder + * is used. + * received - True if this signal has ever been received. + * lastValue - The last received value of the signal. If 'received' is false, + * this value is undefined. + */ +struct CanSignal { + struct CanMessageDefinition* message; + const char* genericName; + uint8_t bitPosition; + uint8_t bitSize; + float factor; + float offset; + float minValue; + float maxValue; + FrequencyClock frequencyClock; + bool sendSame; + bool forceSendChanged; + const CanSignalState* states; + uint8_t stateCount; + bool writable; + SignalDecoder decoder; + SignalEncoder encoder; + bool received; + float lastValue; +}; +typedef struct CanSignal CanSignal; + +/* Public: The definition of a CAN message. This includes a lot of metadata, so + * to save memory this struct should not be used for storing incoming and + * outgoing CAN messages. + * + * bus - A pointer to the bus this message is on. + * id - The ID of the message. + * format - the format of the message's ID. + * frequencyClock - an optional frequency clock to control the output of this + * message, if sent raw, or simply to mark the max frequency for custom + * handlers to retrieve. + * forceSendChanged - If true, regardless of the frequency, it will send CAN + * message if it has changed when using raw passthrough. + * lastValue - The last received value of the message. Defaults to undefined. + * This is required for the forceSendChanged functionality, as the stack + * needs to compare an incoming CAN message with the previous frame. + */ +struct CanMessageDefinition { + struct CanBus* bus; + uint32_t id; + CanMessageFormat format; + FrequencyClock frequencyClock; + bool forceSendChanged; + uint8_t lastValue[CAN_MESSAGE_SIZE]; +}; +typedef struct CanMessageDefinition CanMessageDefinition; + +/* A compact representation of a single CAN message, meant to be used in in/out + * buffers. + * + * id - The ID of the message. + * format - the format of the message's ID. + * data - The message's data field. + * length - the length of the data array (max 8). + */ +struct CanMessage { + uint32_t id; + CanMessageFormat format; + uint8_t data[CAN_MESSAGE_SIZE]; + uint8_t length; +}; +typedef struct CanMessage CanMessage; + +QUEUE_DECLARE(CanMessage, 8); + +/* Private: An entry in the list of acceptance filters for each CanBus. + * + * This struct is meant to be used with a LIST type from <sys/queue.h>. + * + * filter - the value for the CAN acceptance filter. + * activeUserCount - The number of active consumers of this filter's messages. + * When 0, this filter can be removed. + * format - the format of the ID for the filter. +struct AcceptanceFilterListEntry { + uint32_t filter; + uint8_t activeUserCount; + CanMessageFormat format; + LIST_ENTRY(AcceptanceFilterListEntry) entries; +}; + */ + +/* Private: A type of list containing CAN acceptance filters. +LIST_HEAD(AcceptanceFilterList, AcceptanceFilterListEntry); + +struct CanMessageDefinitionListEntry { + CanMessageDefinition definition; + LIST_ENTRY(CanMessageDefinitionListEntry) entries; +}; +LIST_HEAD(CanMessageDefinitionList, CanMessageDefinitionListEntry); + */ + +/** Public: A parent wrapper for a particular set of CAN messages and associated + * CAN buses(e.g. a vehicle or program). + * + * index - A numerical ID for the message set, ideally the index in an array + * for fast lookup + * name - The name of the message set. + * busCount - The number of CAN buses defined for this message set. + * messageCount - The number of CAN messages (across all buses) defined for + * this message set. + * signalCount - The number of CAN signals (across all messages) defined for + * this message set. + * commandCount - The number of CanCommmands defined for this message set. + */ +typedef struct { + uint8_t index; + const char* name; + uint8_t busCount; + unsigned short messageCount; + unsigned short signalCount; + unsigned short commandCount; +} CanMessageSet; + +/* Public: The type signature for a function to handle a custom OpenXC command. + * + * name - the name of the received command. + * value - the value of the received command, in a DynamicField. The actual type + * may be a number, string or bool. + * event - an optional event from the received command, in a DynamicField. The + * actual type may be a number, string or bool. + * signals - The list of all signals. + * signalCount - The length of the signals array. + */ +typedef void (*CommandHandler)(const char* name, openxc_DynamicField* value, + openxc_DynamicField* event, CanSignal* signals, int signalCount); + +/* Public: The structure to represent a supported custom OpenXC command. + * + * For completely customized CAN commands without a 1-1 mapping between an + * OpenXC message from the host and a CAN signal, you can define the name of the + * command and a custom function to handle it in the VI. An example is + * the "turn_signal_status" command in OpenXC, which has a value of "left" or + * "right". The vehicle may have separate CAN signals for the left and right + * turn signals, so you will need to implement a custom command handler to send + * the correct signals. + * + * Command handlers are also useful if you want to trigger multiple CAN messages + * or signals from a signal OpenXC message. + * + * genericName - The name of the command. + * handler - An function to process the received command's data and perform some + * action. + */ +typedef struct { + const char* genericName; + CommandHandler handler; +} CanCommand; + +/* Pre initialize actions made before CAN bus initialization + * + * bus - A CanBus struct defining the bus's metadata + * writable - configure the controller in a writable mode. If false, it will be + * configured as "listen only" and will not allow writes or even CAN ACKs. + * buses - An array of all CAN buses. + * busCount - The length of the buses array. + */ +void pre_initialize(CanBus* bus, bool writable, CanBus* buses, const int busCount); + +/* Post-initialize actions made after CAN bus initialization and before the + * event loop connection. + * + * bus - A CanBus struct defining the bus's metadata + * writable - configure the controller in a writable mode. If false, it will be + * configured as "listen only" and will not allow writes or even CAN ACKs. + * buses - An array of all CAN buses. + * busCount - The length of the buses array. + */ +void post_initialize(CanBus* bus, bool writable, CanBus* buses, const int busCount); + +/* Public: Check if the device is connected to an active CAN bus, i.e. it's + * received a message in the recent past. + * + * Returns true if a message was received on the CAN bus within + * CAN_ACTIVE_TIMEOUT_S seconds. + */ +bool isBusActive(CanBus* bus); + +/* Public: Log transfer statistics about all active CAN buses to the debug log. + * + * buses - an array of active CAN buses. + * busCount - the length of the buses array. + */ +void logBusStatistics(CanBus* buses, const int busCount); |