Make use of C++ standard library

config.hpp

@@ -0,0 +1,63 @@
+#pragma once
+
+#include <cstdint>
+
+#include "../io/io.hpp"
+
+namespace spi {
+
+enum class ClockDiv {
+	DIV_4 = 0,
+	DIV_16 = 1,
+	DIV_64 = 2,
+	DIV_128 = 3,
+
+	DIV_2X_2 = 4,
+	DIV_2X_8 = 5,
+	DIV_2X_32 = 6,
+	DIV_2X_64 = 7,
+};
+
+enum class Mode {
+	MODE_0 = 0,
+	MODE_1 = 1,
+	MODE_2 = 2,
+	MODE_3 = 3,
+};
+
+enum class Side {
+	MASTER,
+	SLAVE,
+};
+
+enum class BitOrder {
+	LSB_FIRST,
+	MSB_FIRST,
+};
+
+template <ClockDiv freq = ClockDiv::DIV_128, Mode mode = Mode::MODE_0, Side side = Side::MASTER,
+          BitOrder bitOrder = BitOrder::MSB_FIRST, io::P ssPin = io::P::B2, bool pullup = false>
+struct HardwareConfig {
+	static constexpr auto FREQ = freq;
+	static constexpr auto MODE = mode;
+	static constexpr auto SIDE = side;
+	static constexpr auto BIT_ORDER = bitOrder;
+	static constexpr auto SS_PIN = ssPin;
+	static constexpr auto PULLUP = pullup;
+};
+
+template <io::P sckPin, io::P misoPin, io::P mosiPin, io::P ssPin, std::uint32_t freq = 100'000,
+          Mode mode = Mode::MODE_0, BitOrder bitOrder = BitOrder::MSB_FIRST, std::uint8_t bits = 8, bool pullup = false>
+struct SoftwareConfig {
+	static constexpr auto SCK_PIN = sckPin;
+	static constexpr auto MISO_PIN = misoPin;
+	static constexpr auto MOSI_PIN = mosiPin;
+	static constexpr auto SS_PIN = ssPin;
+	static constexpr auto FREQ = freq;
+	static constexpr auto MODE = mode;
+	static constexpr auto BIT_ORDER = bitOrder;
+	static constexpr auto BITS = bits;
+	static constexpr auto PULLUP = pullup;
+};
+
+} // namespace spi

hardware.hpp

@@ -0,0 +1,139 @@
+#pragma once
+
+#include <cstdint>
+
+#include "../io/io.hpp"
+
+namespace spi {
+
+#if defined(__AVR_ATmega328P__)
+
+template <class Cfg>
+class Hardware {
+  public:
+	using word_t = std::uint8_t;
+
+	static void init()
+	{
+		if constexpr (Cfg::SIDE == Side::MASTER) {
+			sm_ss = true;
+
+			sm_sck.dir(io::Dir::OUT);
+			sm_miso.dir(io::Dir::IN);
+			sm_miso.pullup(Cfg::PULLUP);
+			sm_mosi.dir(io::Dir::OUT);
+			sm_ss.dir(io::Dir::OUT);
+		} else {
+			sm_sck.dir(io::Dir::IN);
+			sm_miso.dir(io::Dir::OUT);
+			sm_mosi.dir(io::Dir::IN);
+			sm_ss.dir(io::Dir::IN);
+			sm_ss.pullup(true);
+		}
+
+		setClockDiv();
+		setMode();
+		setMaster();
+		setBitOrder();
+
+		SPCR = SPCR | (1 << SPE);
+	}
+
+	static word_t transfer(word_t data)
+	{
+		SPDR = data;
+		while (!(SPSR & (1 << SPIF)))
+			;
+		return SPDR;
+	}
+
+	static void select(bool selectState)
+	{
+		sm_ss = !selectState;
+	}
+
+  private:
+	static io::Pin<io::P::B5> sm_sck;
+	static io::Pin<io::P::B4> sm_miso;
+	static io::Pin<io::P::B3> sm_mosi;
+	static io::Pin<Cfg::SS_PIN> sm_ss;
+
+	static void setClockDiv()
+	{
+		std::uint8_t ui8ClockDiv = static_cast<std::uint8_t>(Cfg::FREQ);
+
+		if (ui8ClockDiv & 1) {
+			SPCR = SPCR | (1 << SPR0);
+		} else {
+			SPCR = SPCR & ~(1 << SPR0);
+		}
+
+		if (ui8ClockDiv & (1 << 1)) {
+			SPCR = SPCR | (1 << SPR1);
+		} else {
+			SPCR = SPCR & ~(1 << SPR1);
+		}
+
+		if (ui8ClockDiv & (1 << 2)) {
+			SPSR = SPSR | (1 << SPI2X);
+		} else {
+			SPSR = SPSR & ~(1 << SPI2X);
+		}
+	}
+
+	static void setMode()
+	{
+		if (Cfg::MODE == Mode::MODE_0 || Cfg::MODE == Mode::MODE_1) {
+			setCPOL(false);
+		} else {
+			setCPOL(true);
+		}
+
+		if (Cfg::MODE == Mode::MODE_0 || Cfg::MODE == Mode::MODE_2) {
+			setCPHA(false);
+		} else {
+			setCPHA(true);
+		}
+	}
+
+	static void setMaster()
+	{
+		if constexpr (Cfg::SIDE == Side::MASTER) {
+			SPCR = SPCR | (1 << MSTR);
+		} else {
+			SPCR = SPCR & ~(1 << MSTR);
+		}
+	}
+
+	static void setBitOrder()
+	{
+		if constexpr (Cfg::BIT_ORDER == BitOrder::LSB_FIRST) {
+			SPCR = SPCR | (1 << DORD);
+		} else {
+			SPCR = SPCR & ~(1 << DORD);
+		}
+	}
+
+	static void setCPOL(bool bCPOL)
+	{
+		if (bCPOL) {
+			SPCR = SPCR | (1 << CPOL);
+		} else {
+			SPCR = SPCR & ~(1 << CPOL);
+		}
+	}
+	static void setCPHA(bool bCPHA)
+	{
+		if (bCPHA) {
+			SPCR = SPCR | (1 << CPHA);
+		} else {
+			SPCR = SPCR & ~(1 << CPHA);
+		}
+	}
+};
+
+#else
+#error "This chip is not supported"
+#endif
+
+} // namespace spi

software.hpp

@@ -0,0 +1,114 @@
+#pragma once
+
+#include "../clock.hpp"
+
+#include <type_traits>
+#include <utility>
+
+#include <cstdint>
+
+#include <avr/interrupt.h>
+
+#include "../io/io.hpp"
+#include "../util/util.hpp"
+
+namespace spi {
+
+template <typename Cfg>
+class Software {
+	static constexpr double calcClockDelay()
+	{
+		constexpr auto staticClockCycles = 10;
+		constexpr auto maxFrequency = F_CPU / staticClockCycles;
+		static_assert(Cfg::FREQ <= maxFrequency, "SPI frequency not achievable using selected clock speed");
+		constexpr auto staticDelay = (1.0 * 1000 * 1000 / maxFrequency);
+		const auto delayUs = ((1.0 * 1000 * 1000 / Cfg::FREQ) - staticDelay) / 2;
+		return (delayUs > 0 ? delayUs : 0);
+	}
+
+  public:
+	static_assert(Cfg::BITS >= 1 && Cfg::BITS <= 64, "Word size must be in range [1-64]");
+	// clang-format off
+	using word_t = std::conditional_t<Cfg::BITS <=  8, std::uint8_t,
+	               std::conditional_t<Cfg::BITS <= 16, std::uint16_t,
+	               std::conditional_t<Cfg::BITS <= 32, std::uint32_t,
+	                                                   std::uint64_t>>>;
+	// clang-format on
+
+	static void init()
+	{
+		sm_sck = ((Cfg::MODE == Mode::MODE_0 || Cfg::MODE == Mode::MODE_1) ? false : true);
+		sm_ss = true;
+
+		sm_sck.dir(io::Dir::OUT);
+		sm_miso.dir(io::Dir::IN);
+		sm_miso.pullup(Cfg::PULLUP);
+		sm_mosi.dir(io::Dir::OUT);
+		sm_ss.dir(io::Dir::OUT);
+	}
+
+	static word_t transfer(const word_t data)
+	{
+		const auto oldInterruptState = disableInterrupts();
+
+		auto dataIn = word_t{};
+
+		util::for_constexpr(
+		    [&](const auto idx) {
+			    constexpr auto i = idx.value;
+			    constexpr auto bitPos = (Cfg::BIT_ORDER == BitOrder::MSB_FIRST ? Cfg::BITS - i - 1 : i);
+
+			    if constexpr (Cfg::MODE == Mode::MODE_0 || Cfg::MODE == Mode::MODE_2) {
+				    sm_mosi = data >> bitPos & 1;
+				    _delay_us(DELAY_US);
+				    sm_sck.toggle();
+
+				    const auto receivedBit = sm_miso.read();
+				    dataIn |= word_t{receivedBit} << bitPos;
+				    _delay_us(DELAY_US);
+				    sm_sck.toggle();
+			    } else {
+				    sm_sck.toggle();
+				    sm_mosi = data >> bitPos & 1;
+				    _delay_us(DELAY_US);
+
+				    sm_sck.toggle();
+				    const auto receivedBit = sm_miso.read();
+				    dataIn |= word_t{receivedBit} << bitPos;
+				    _delay_us(DELAY_US);
+			    }
+		    },
+		    std::make_index_sequence<Cfg::BITS>{});
+
+		enableInterrupts(oldInterruptState);
+
+		return dataIn;
+	}
+
+	static void select(const bool selectState)
+	{
+		sm_ss = !selectState;
+	}
+
+  private:
+	static io::Pin<Cfg::SCK_PIN> sm_sck;
+	static io::Pin<Cfg::MISO_PIN> sm_miso;
+	static io::Pin<Cfg::MOSI_PIN> sm_mosi;
+	static io::Pin<Cfg::SS_PIN> sm_ss;
+
+	static constexpr auto DELAY_US = calcClockDelay();
+
+	static inline std::uint8_t disableInterrupts()
+	{
+		const auto oldInterruptState = SREG;
+		cli();
+		return oldInterruptState;
+	}
+
+	static inline void enableInterrupts(const std::uint8_t oldInterruptState)
+	{
+		SREG = oldInterruptState;
+	}
+};
+
+} // namespace spi

spi.hpp

@@ -1,160 +1,30 @@
 #pragma once
 
+#include "config.hpp"
+#include "hardware.hpp"
+#include "software.hpp"
+
 #include "../io/io.hpp"
 
-#include <avr/io.h>
-
 namespace spi {
 
-class Spi {
-  public:
-	enum class ClockDiv {
-		CLKDIV_4 = 0,
-		CLKDIV_16 = 1,
-		CLKDIV_64 = 2,
-		CLKDIV_128 = 3,
+template <class Driver>
+struct Spi {
+	using word_t = typename Driver::word_t;
 
-		CLKDIV_2X_2 = 4,
-		CLKDIV_2X_8 = 5,
-		CLKDIV_2X_32 = 6,
-		CLKDIV_2X_64 = 7,
-	};
-
-	enum class Mode {
-		MODE_0 = 0,
-		MODE_1 = 1,
-		MODE_2 = 2,
-		MODE_3 = 3,
-	};
-
-  private:
-	static void setCPOL(bool bCPOL)
+	static inline void init()
 	{
-		if (bCPOL) {
-			SPCR |= (1 << CPOL);
-		} else {
-			SPCR &= ~(1 << CPOL);
-		}
-	}
-	static void setCPHA(bool bCPHA)
-	{
-		if (bCPHA) {
-			SPCR |= (1 << CPHA);
-		} else {
-			SPCR &= ~(1 << CPHA);
-		}
+		Driver::init();
 	}
 
-	static io::Pin<io::P::B5> sm_cSCK;
-	static io::Pin<io::P::B4> sm_cMISO;
-	static io::Pin<io::P::B3> sm_cMOSI;
-	static io::Pin<io::P::B2> sm_cSS;
-
-  public:
-	static void init(ClockDiv enmClockDiv = ClockDiv::CLKDIV_128, Mode enmMode = Mode::MODE_0, bool bMaster = true,
-	                 bool bLSBFirst = false, bool bMISOPullup = false)
+	static inline word_t transfer(const word_t data)
 	{
-		if (bMaster) {
-			sm_cSS.write(true);
-
-			sm_cSCK.dir(io::Dir::OUT);
-			sm_cMISO.dir(io::Dir::IN);
-			sm_cMISO.pullup(bMISOPullup);
-			sm_cMOSI.dir(io::Dir::OUT);
-			sm_cSS.dir(io::Dir::OUT);
-		} else {
-			sm_cSCK.dir(io::Dir::IN);
-			sm_cMISO.dir(io::Dir::OUT);
-			sm_cMOSI.dir(io::Dir::IN);
-			sm_cSS.dir(io::Dir::IN);
-			sm_cSS.pullup(true);
-		}
-
-		setClockDiv(enmClockDiv);
-		setMode(enmMode);
-		setMaster(bMaster);
-		setBitOrder(bLSBFirst);
-
-		SPCR |= (1 << SPE);
+		return Driver::transfer(data);
 	}
 
-	static void deinit()
+	static inline void select(const bool selectState)
 	{
-		SPCR = 0;
-
-		sm_cSCK.dir(io::Dir::IN);
-		sm_cMISO.dir(io::Dir::IN);
-		sm_cMOSI.dir(io::Dir::IN);
-		sm_cSS.dir(io::Dir::IN);
-	}
-
-	static void setClockDiv(ClockDiv enmClockDiv)
-	{
-		uint8_t ui8ClockDiv = static_cast<uint8_t>(enmClockDiv);
-
-		if (ui8ClockDiv & 1) {
-			SPCR |= (1 << SPR0);
-		} else {
-			SPCR &= ~(1 << SPR0);
-		}
-
-		if (ui8ClockDiv & (1 << 1)) {
-			SPCR |= (1 << SPR1);
-		} else {
-			SPCR &= ~(1 << SPR1);
-		}
-
-		if (ui8ClockDiv & (1 << 2)) {
-			SPSR |= (1 << SPI2X);
-		} else {
-			SPSR &= ~(1 << SPI2X);
-		}
-	}
-
-	static void setMode(Mode enmMode)
-	{
-		if (enmMode == Mode::MODE_0 || enmMode == Mode::MODE_1) {
-			setCPOL(false);
-		} else {
-			setCPOL(true);
-		}
-
-		if (enmMode == Mode::MODE_0 || enmMode == Mode::MODE_2) {
-			setCPHA(false);
-		} else {
-			setCPHA(true);
-		}
-	}
-
-	static void setMaster(bool bMaster)
-	{
-		if (bMaster) {
-			SPCR |= (1 << MSTR);
-		} else {
-			SPCR &= ~(1 << MSTR);
-		}
-	}
-
-	static void setBitOrder(bool bLSBFirst)
-	{
-		if (bLSBFirst) {
-			SPCR |= (1 << DORD);
-		} else {
-			SPCR &= ~(1 << DORD);
-		}
-	}
-
-	static uint8_t transfer(uint8_t ui8Data)
-	{
-		SPDR = ui8Data;
-		while (!(SPSR & (1 << SPIF)))
-			;
-		return SPDR;
-	}
-
-	static void select(bool bSelect)
-	{
-		sm_cSS.write(!bSelect);
+		Driver::select(selectState);
 	}
 };