clock.hpp

00001 /*
00002  * Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
00003  */
00004 
00005 #pragma once
00006 
00007 #include <uavcan/driver/system_clock.hpp>
00008 
00009 namespace uavcan_lpc11c24
00010 {
00011 namespace clock
00012 {
00013 /**
00014  * Starts the clock.
00015  * Can be called multiple times, only the first call will be effective.
00016  */
00017 void init();
00018 
00019 /**
00020  * Returns current monotonic time passed since the moment when clock::init() was called.
00021  * Note that both monotonic and UTC clocks are implemented using SysTick timer.
00022  */
00023 uavcan::MonotonicTime getMonotonic();
00024 
00025 /**
00026  * Returns UTC time if it has been set, otherwise returns zero time.
00027  * Note that both monotonic and UTC clocks are implemented using SysTick timer.
00028  */
00029 uavcan::UtcTime getUtc();
00030 
00031 /**
00032  * Performs UTC time adjustment.
00033  * The UTC time will be zero until first adjustment has been performed.
00034  */
00035 void adjustUtc(uavcan::UtcDuration adjustment);
00036 
00037 /**
00038  * Returns clock error sampled at previous UTC adjustment.
00039  * Positive if the hardware timer is slower than reference time.
00040  */
00041 uavcan::UtcDuration getPrevUtcAdjustment();
00042 
00043 }
00044 
00045 /**
00046  * Adapter for uavcan::ISystemClock.
00047  */
00048 class SystemClock : public uavcan::ISystemClock, uavcan::Noncopyable
00049 {
00050     static SystemClock self;
00051 
00052     SystemClock() { }
00053 
00054     uavcan::MonotonicTime getMonotonic()     const override { return clock::getMonotonic(); }
00055     uavcan::UtcTime getUtc()                 const override { return clock::getUtc(); }
00056     void adjustUtc(uavcan::UtcDuration adjustment) override { clock::adjustUtc(adjustment); }
00057 
00058 public:
00059     /**
00060      * Calls clock::init() as needed.
00061      */
00062     static SystemClock& instance();
00063 };
00064 
00065 }