libpfr/inc/spiDev.hpp

/*
// Copyright (c) 2019 Intel Corporation
//
// 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 <stdio.h>

#include <cstring>
#include <experimental/filesystem>

namespace intel
{
namespace pfr
{

/** @class SPIDev
 *  @brief Responsible for handling file pointer
 */
class SPIDev
{
  private:
    /** @brief handler for operating on file */
    int fd = -1;

  public:
    SPIDev() = delete;
    SPIDev(const SPIDev&) = delete;
    SPIDev& operator=(const SPIDev&) = delete;
    SPIDev(SPIDev&&) = delete;
    SPIDev& operator=(SPIDev&&) = delete;

    /** @brief Opens spi(mtd) device file
     *
     *  @param[in] devNo       - MTD device number
     */
    SPIDev(const std::string& spiDev) :
        fd(open(spiDev.c_str(), O_RDWR | O_CLOEXEC))
    {
        if (fd < 0)
        {
            std::string msg = "Unable to open mtd device. errno=" +
                              std::string(std::strerror(errno));
            throw std::runtime_error(msg);
        }
    }

    /** @brief Reads the byte data from SPI(MTD) device
     *
     *  @param[in] startAddr    - start address
     *  @param[in] dataLen      - No of byte to read
     *  @param[out] dataRes     - Out data pointer
     */
    void spiReadData(const uint32_t startAddr, const size_t dataLen,
                     void* dataRes)
    {
        if (lseek(fd, startAddr, SEEK_SET) < 0)
        {
            std::string msg = "Failed to do lseek on mtd device. errno=" +
                              std::string(std::strerror(errno));
            throw std::runtime_error(msg);
        }

        if (read(fd, dataRes, dataLen) != dataLen)
        {
            std::string msg = "Failed to read on mtd device. errno=" +
                              std::string(std::strerror(errno));
            throw std::runtime_error(msg);
        }

        return;
    }

    virtual ~SPIDev()
    {
        if (!(fd < 0))
        {
            close(fd);
        }
    }
};

} // namespace pfr
} // namespace intel