CanDriver.h

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/* Copyright (c) 2021 Skyward Experimental Rocketry
 * Author: Luca Erbetta
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 
#pragma once
 
#include <interfaces-impl/arch_registers_impl.h>
#include <miosix.h>
#include <utils/collections/IRQCircularBuffer.h>
 
#include <chrono>
 
#include "CanDriverData.h"
#include "Filters.h"
 
using miosix::Thread;
 
namespace Boardcore
{
 
namespace Canbus
{
 
class CanbusDriver
{
    // How many frames to store in the RX buffer
    static constexpr unsigned int RX_BUF_SIZE        = 32;
    static constexpr unsigned int TX_STATUS_BUF_SIZE = 32;
 
    // Weight coefficients for calculating the optimal bit timing
    static constexpr float BR_ERR_WEIGHT = 10;
    static constexpr float SP_ERR_WEIGHT = 1;
    static constexpr float N_ERR_WEIGHT  = 1 / 50;
 
    static constexpr uint8_t NUM_FILTER_BANKS = 28;
 
public:
    struct CanbusConfig
    {
        uint8_t loopback = 0;  // 1: Loopback mode enabled
        uint8_t awum     = 1;  // Automatic wakeup (1: automatic wakeup upon new
                               // message received)
        uint8_t nart =
            0;  // No auto retransmission (0: packets are retransmitted until
                // success, 1: only one transfer attempt)
        uint8_t abom = 1;  // Automatic bus off management (1: automatically
                           // recovers from bus-off state)
        uint8_t rflm = 1;  // Receive fifo locked (0: new messages overwrite
                           // last ones, 1: new message discarded)
        uint8_t txfp = 1;  // TX Fifo priority (0: identifier, 1: chronological)
    };
 
    struct AutoBitTiming
    {
        uint32_t baudRate;
 
        float samplePoint;
    };
 
    struct BitTiming
    {
        uint16_t BRP;
        uint16_t BS1;
        uint16_t BS2;
        uint8_t SJW;
    };
 
    CanbusDriver(CAN_TypeDef* can, CanbusConfig config,
                 AutoBitTiming bitTiming);
 
    CanbusDriver(CAN_TypeDef* can, CanbusConfig config, BitTiming bitTiming);
 
    ~CanbusDriver();
 
    bool init(
        std::chrono::milliseconds timeout = std::chrono::milliseconds::zero());
 
    bool addFilter(FilterBank filter);
 
    uint32_t send(CanPacket packet);
 
    IRQCircularBuffer<CanRXPacket, RX_BUF_SIZE>& getRXBuffer()
    {
        return bufRxPackets;
    }
 
    IRQCircularBuffer<CanTXResult, TX_STATUS_BUF_SIZE>& getTXResultBuffer()
    {
        return bufTxResult;
    }
 
    CAN_TypeDef* getCAN() { return can; }
 
    uint32_t getTXMailboxSequence(uint8_t i) { return txMailboxSeq[i]; }
 
    void wakeTXThread();
 
    void handleRXInterrupt(int fifo);
 
private:
    static BitTiming calcBitTiming(AutoBitTiming config);
 
    // Stores RX packets
    IRQCircularBuffer<CanRXPacket, RX_BUF_SIZE> bufRxPackets;
 
    // Store results of a TX request
    IRQCircularBuffer<CanTXResult, TX_STATUS_BUF_SIZE> bufTxResult;
 
    CAN_TypeDef* can;
 
    uint32_t txSeq           = 1;    // TX packet sequence number
    uint32_t txMailboxSeq[3] = {0};  // Seq. no. of packets in the TX mailbox
 
    uint8_t isInit      = false;
    uint8_t filterIndex = 0;
    Thread* waiting     = nullptr;
};
 
}  // namespace Canbus
 
}  // namespace Boardcore