From 3c8fce14f642d1448973d49e1dc83530d20b32c3 Mon Sep 17 00:00:00 2001
From: Henrik Stickann <4376396-Mithradir@users.noreply.gitlab.com>
Date: Fri, 15 Apr 2022 14:55:49 +0200
Subject: [PATCH] Add SPI settings

---
 include/sta/spi_settings.hpp | 71 +++++++++++++++++++++++++++++++++++
 src/spi_settings.cpp         | 72 ++++++++++++++++++++++++++++++++++++
 2 files changed, 143 insertions(+)
 create mode 100644 include/sta/spi_settings.hpp
 create mode 100644 src/spi_settings.cpp

diff --git a/include/sta/spi_settings.hpp b/include/sta/spi_settings.hpp
new file mode 100644
index 0000000..ec89f56
--- /dev/null
+++ b/include/sta/spi_settings.hpp
@@ -0,0 +1,71 @@
+#ifndef STA_SPI_SETTINGS_HPP
+#define STA_SPI_SETTINGS_HPP
+
+#include <cstdint>
+
+
+namespace sta
+{
+	enum class SpiClkPolarity
+	{
+		LOW,
+		HIGH
+	};
+
+	enum class SpiClkPhase
+	{
+		EDGE_1,
+		EDGE_2
+	};
+
+	enum class SpiMode
+	{
+		MODE_0,
+		MODE_1,
+		MODE_2,
+		MODE_3
+	};
+
+	enum class SpiDataSize
+	{
+		BIT_8,
+		BIT_16
+	};
+
+	enum class SpiBitOrder
+	{
+		MSB,
+		LSB
+	};
+
+	enum class SpiBaudRatePrescaler
+	{
+		BRP_2,
+		BRP_4,
+		BRP_8,
+		BRP_16,
+		BRP_32,
+		BRP_64,
+		BRP_128,
+		BRP_256
+	};
+
+
+	struct SpiSettings
+	{
+		SpiMode     mode;
+		SpiDataSize dataSize;
+		SpiBitOrder bitOrder;
+
+		uint32_t    clkSpeed;
+		SpiBaudRatePrescaler baudRatePrescaler; /**< Subject to change */
+	};
+
+
+	SpiClkPolarity getSpiClkPolarity(SpiMode mode);
+	SpiClkPhase    getSpiClkPhase(SpiMode mode);
+	SpiMode        getSpiMode(SpiClkPolarity polarity, SpiClkPhase phase);
+} // namespace sta
+
+
+#endif // STA_SPI_SETTINGS_HPP
diff --git a/src/spi_settings.cpp b/src/spi_settings.cpp
new file mode 100644
index 0000000..73478e7
--- /dev/null
+++ b/src/spi_settings.cpp
@@ -0,0 +1,72 @@
+#include <sta/spi_settings.hpp>
+
+#include <sta/assert.hpp>
+#include <sta/lang.hpp>
+
+
+namespace sta
+{
+	SpiClkPolarity getSpiClkPolarity(SpiMode mode)
+	{
+		switch (mode)
+		{
+		case SpiMode::MODE_0:
+		case SpiMode::MODE_1:
+			return SpiClkPolarity::LOW;
+
+		case SpiMode::MODE_2:
+		case SpiMode::MODE_3:
+			return SpiClkPolarity::HIGH;
+
+		default:
+			// Unreachable case
+			STA_ASSERT_MSG(false, "Case for SpiMode enum not handled");
+			STA_UNREACHABLE();
+		}
+	}
+
+	SpiClkPhase getSpiClkPhase(SpiMode mode)
+	{
+		switch (mode)
+		{
+		case SpiMode::MODE_0:
+		case SpiMode::MODE_2:
+			return SpiClkPhase::EDGE_1;
+
+		case SpiMode::MODE_1:
+		case SpiMode::MODE_3:
+			return SpiClkPhase::EDGE_2;
+
+		default:
+			// Unreachable case
+			STA_ASSERT_MSG(false, "Case for SpiMode enum not handled");
+			STA_UNREACHABLE();
+		}
+	}
+
+	SpiMode getSpiMode(SpiClkPolarity polarity, SpiClkPhase phase)
+	{
+		if (polarity == SpiClkPolarity::LOW)
+		{
+			if (phase == SpiClkPhase::EDGE_1)
+			{
+				return SpiMode::MODE_0;
+			}
+			else
+			{
+				return SpiMode::MODE_1;
+			}
+		}
+		else
+		{
+			if (phase == SpiClkPhase::EDGE_1)
+			{
+				return SpiMode::MODE_2;
+			}
+			else
+			{
+				return SpiMode::MODE_3;
+			}
+		}
+	}
+} // namespace sta