Add SPI device interface

include/sta/spi_device.hpp

@@ -0,0 +1,94 @@
+#ifndef STA_SPI_DEVICE_HPP
+#define STA_SPI_DEVICE_HPP
+
+#include <sta/spi_interface.hpp>
+
+#include <stdint.h>
+#include <stddef.h>
+
+
+namespace sta
+{
+	/**
+	 * @brief Interface for SPI devices.
+	 */
+	class SpiDevice
+	{
+	public:
+		/**
+		 * @param intf  SPI hardware interface
+		 */
+		SpiDevice(SpiInterface * intf);
+
+		/**
+		 * @brief Start transmission with device.
+		 *
+		 * Must be called before any I/O operations.
+		 */
+		void beginTransmission();
+		/**
+		 * @brief End transmission with device.
+		 *
+		 * Must be called after last I/O operation.
+		 */
+		void endTransmission();
+
+		/**
+		 * @brief Send single byte of data.
+		 *
+		 * @param value     8-bit value
+		 */
+		void transfer(uint8_t value);
+		/**
+		 * @brief Send data from buffer.
+		 *
+		 * @param buffer    Source buffer
+		 * @param size      Number of bytes in buffer
+		 */
+		void transfer(const uint8_t * buffer, size_t size);
+		/**
+		 * @brief Send two bytes of data.
+		 *
+		 * @param value     16-bit value
+		 */
+		void transfer16(uint16_t data);
+
+		/**
+		 * @brief Send byte value repeatedly.
+		 *
+		 * @param value     8-bit value to repeat
+		 * @param count     Number of repetitions
+		 */
+		void fill(uint8_t value, size_t count);
+		/**
+		 * @brief Send 32-bit value repeatedly.
+		 *
+		 * @param value     32-bit value to repeat
+		 * @param count     Number of repetitions
+		 */
+		void fill32(uint32_t value, size_t count);
+
+		/**
+		 * @brief Read incoming data to buffer.
+		 *
+		 * @param buffer    Destination buffer
+		 * @param size      Number of bytes to read
+		 */
+		void receive(uint8_t * buffer, size_t size);
+
+		/**
+		 * @brief Activate device via CS pin.
+		 */
+		virtual void select() = 0;
+		/**
+		 * @brief Deactivate device via CS pin.
+		 */
+		virtual void deselect() = 0;
+
+	private:
+		SpiInterface * intf_;   /**< SPI hardware interface */
+	};
+} // namespace sta
+
+
+#endif // STA_SPI_DEVICE_HPP

src/spi_device.cpp

@@ -0,0 +1,56 @@
+#include <sta/spi_device.hpp>
+
+
+namespace sta
+{
+	SpiDevice::SpiDevice(SpiInterface * intf)
+		: intf_{intf}
+	{}
+
+	void SpiDevice::beginTransmission()
+	{
+		// Acquire SPI access and activate device
+		intf_->acquire();
+		select();
+	}
+
+	void SpiDevice::endTransmission()
+	{
+		// Deactivate device and release SPI access
+		deselect();
+		intf_->release();
+	}
+
+
+	// Forward I/O operations to SPI interface
+
+	void SpiDevice::transfer(uint8_t data)
+	{
+		intf_->transfer(data);
+	}
+
+	void SpiDevice::transfer(const uint8_t * data, size_t size)
+	{
+		intf_->transfer(data, size);
+	}
+
+	void SpiDevice::transfer16(uint16_t data)
+	{
+		intf_->transfer16(data);
+	}
+
+	void SpiDevice::fill(uint8_t value, size_t count)
+	{
+		intf_->fill(value, count);
+	}
+
+	void SpiDevice::fill32(uint32_t value, size_t count)
+	{
+		intf_->fill32(value, count);
+	}
+
+	void SpiDevice::receive(uint8_t * buffer, size_t size)
+	{
+		intf_->receive(buffer, size);
+	}
+} // namespace sta