PFR: Reading bmc version from SPI

Added support to pull BMC active and recovery image version
from PFM region of associated MTD device instead of CPLD.
Becuase CPLD has provision to hold only major and minor version
but PFM in PFR image will have more information about version
(major, minor, build number and build hash etc...). So added SPI
device read capability and read BMC active/recovery image version
from PFM.

Tested:
Fetched FirmwareInventory information from redfish, using
below URI and verified BMC active & recovery version has build
number along with major and minor numbers.

URI:
/redfish/v1/UpdateService/FirmwareInventory/bmc_active
/redfish/v1/UpdateService/FirmwareInventory/bmc_recovery

RESPONSE:
"Version": "00.11-07-1e5c2d"

Change-Id: I3d8176f776992a1b0454046a1b8ebd33d84a91d3
Signed-off-by: AppaRao Puli <apparao.puli@linux.intel.com>
diff --git a/libpfr/inc/spiDev.hpp b/libpfr/inc/spiDev.hpp
new file mode 100644
index 0000000..17a4f63
--- /dev/null
+++ b/libpfr/inc/spiDev.hpp
@@ -0,0 +1,95 @@
+/*
+// 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