Spi.h

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/* Copyright 2013-2019 Homegear GmbH
 *
 * libhomegear-base is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * libhomegear-base is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with libhomegear-base.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU Lesser General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
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*/

#ifndef SPI_H_
#define SPI_H_

#ifdef SPISUPPORT

#include "../Exception.h"

#include <type_traits>
#include <vector>
#include <mutex>
#include <memory>

#include <linux/spi/spidev.h>
#include <sys/ioctl.h>

namespace BaseLib
{

class SharedObjects;
class FileDescriptor;

namespace LowLevel
{

class SpiException : public Exception
{
public:
    SpiException(std::string message) : Exception(message) {}
};

enum class SpiModes : uint8_t
{
    none = 0,

    loop = SPI_LOOP,

    cpha = SPI_CPHA,

    cpol = SPI_CPOL,

    lsbFirst = SPI_LSB_FIRST,

    csHigh = SPI_CS_HIGH,

    threeWire = SPI_3WIRE,

    noCs = SPI_NO_CS,

    ready = SPI_READY
};

inline SpiModes operator|(SpiModes lhs, SpiModes rhs)
{
    return (SpiModes)(static_cast<std::underlying_type<SpiModes>::type>(lhs) | static_cast<std::underlying_type<SpiModes>::type>(rhs));
}

inline SpiModes& operator|=(SpiModes& lhs, SpiModes rhs)
{
    lhs = (SpiModes)(static_cast<std::underlying_type<SpiModes>::type>(lhs) | static_cast<std::underlying_type<SpiModes>::type>(rhs));
    return lhs;
}

inline SpiModes operator&(SpiModes lhs, SpiModes rhs)
{
    return (SpiModes)(static_cast<std::underlying_type<SpiModes>::type>(lhs) & static_cast<std::underlying_type<SpiModes>::type>(rhs));
}

inline SpiModes& operator&=(SpiModes& lhs, SpiModes rhs)
{
    lhs = (SpiModes)(static_cast<std::underlying_type<SpiModes>::type>(lhs) & static_cast<std::underlying_type<SpiModes>::type>(rhs));
    return lhs;
}

class Spi
{
public:
    Spi(BaseLib::SharedObjects* baseLib, std::string device, SpiModes mode, uint8_t bitsPerWord, uint32_t speed);

    virtual ~Spi();

    void open();
    void close();
    void readwrite(std::vector<uint8_t>& data);

    bool isOpen();
protected:
    BaseLib::SharedObjects* _bl = nullptr;
    std::shared_ptr<FileDescriptor> _fileDescriptor;
    std::string _lockfile;
    std::mutex _sendMutex;
    struct spi_ioc_transfer _transfer;

    std::string _device;
    SpiModes _mode = SpiModes::none;
    uint8_t _bitsPerWord = 8;
    uint32_t _speed = 1000000;

    void setup();
};

}
}
#endif
#endif