PEL: Add BCD time helpers for PELs
A PEL stores time in BCD, with a byte each for:
* year MSB
* year LSB
* month
* day
* hour
* minutes
* seconds
* hundredths
This commit adds a structure to represent this, and functions to:
* Create a BCD structure from a std::chrono::time_point
* Convert any number to BCD
* Write the BCD structure into a Stream
* Extract a BCD structure from a Stream
Refresher: The BCD value of 32 is 0x32.
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I09ea4098f3a3981931f595d11fb63aff31d9fb0d
diff --git a/extensions/openpower-pels/bcd_time.hpp b/extensions/openpower-pels/bcd_time.hpp
new file mode 100644
index 0000000..e218756
--- /dev/null
+++ b/extensions/openpower-pels/bcd_time.hpp
@@ -0,0 +1,88 @@
+#pragma once
+#include "stream.hpp"
+
+#include <chrono>
+
+namespace openpower
+{
+namespace pels
+{
+
+/**
+ * @brief A structure that contains a PEL timestamp in BCD.
+ */
+struct BCDTime
+{
+ uint8_t yearMSB;
+ uint8_t yearLSB;
+ uint8_t month;
+ uint8_t day;
+ uint8_t hour;
+ uint8_t minutes;
+ uint8_t seconds;
+ uint8_t hundredths;
+
+ bool operator==(const BCDTime& right) const;
+ bool operator!=(const BCDTime& right) const;
+
+} __attribute__((packed));
+
+/**
+ * @brief Converts a time_point into a BCD time
+ *
+ * @param[in] time - the time_point to convert
+ * @return BCDTime - the BCD time
+ */
+BCDTime getBCDTime(std::chrono::time_point<std::chrono::system_clock>& time);
+
+/**
+ * @brief Converts a number to a BCD.
+ *
+ * For example 32 -> 0x32.
+ *
+ * Source: PLDM repository
+ *
+ * @param[in] value - the value to convert.
+ *
+ * @return T - the BCD value
+ */
+template <typename T>
+T toBCD(T decimal)
+{
+ T bcd = 0;
+ T remainder = 0;
+ auto count = 0;
+
+ while (decimal)
+ {
+ remainder = decimal % 10;
+ bcd = bcd + (remainder << count);
+ decimal = decimal / 10;
+ count += 4;
+ }
+
+ return bcd;
+}
+
+/**
+ * @brief Stream extraction operator for BCDTime
+ *
+ * @param[in] s - the Stream
+ * @param[out] time - the BCD time
+ *
+ * @return Stream&
+ */
+Stream& operator>>(Stream& s, BCDTime& time);
+
+/**
+ * @brief Stream insertion operator for BCDTime
+ *
+ * @param[in/out] s - the Stream
+ * @param[in] time - the BCD time
+ *
+ * @return Stream&
+ */
+Stream& operator<<(Stream& s, BCDTime& time);
+
+} // namespace pels
+} // namespace openpower