sta-core/include/sta/spi/spi.hpp

/**
 * @file
 * @brief SPI bus software interface.
 */
#ifndef STA_CORE_SPI_SPI_HPP
#define STA_CORE_SPI_SPI_HPP

#include <sta/mutex.hpp>
#include <sta/spi/settings.hpp>

#include <cstddef>
#include <cstdint>


namespace sta
{
    /**
     * @brief Interface class for %SPI hardware.
     *
     * Represents a single %SPI bus that can be shared by multiple devices.
     *
     * @ingroup sta_core_spi
     */
    class SPI
    {
    public:
        /**
         * @param settings  %SPI bus settings
         * @param mutex     Mutex object for managing shared access. Pass nullptr for no access control
         */
        SPI(const SPISettings & settings, Mutex * mutex = nullptr);


        /**
         * @brief Send single byte of data.
         *
         * @param value     8-bit value
         */
        virtual void transfer(uint8_t value) = 0;
        /**
         * @brief Send two bytes of data.
         *
         * @param value     16-bit value
         */
        virtual void transfer16(uint16_t value) = 0;
        /**
         * @brief Send data from buffer.
         *
         * @param buffer    Source buffer
         * @param size      Number of bytes to transfer
         */
        virtual void transfer(const uint8_t * buffer, size_t size) = 0;
        /**
         * @brief Send and receive data simultaneously.
         *
         * @param txBuffer  Send buffer
         * @param rxBuffer  Receive buffer
         * @param size      Number of bytes to transfer
         */
        virtual void transfer(const uint8_t * txBuffer, uint8_t * rxBuffer, size_t size) = 0;
        /**
         * @brief Read incoming data to buffer.
         *
         * @param buffer    Destination buffer
         * @param size      Number of bytes to read
         */
        virtual void receive(uint8_t * buffer, size_t size) = 0;


        /**
         * @brief Send byte value repeatedly.
         *
         * @param value     8-bit value to repeat
         * @param count     Number of repetitions
         */
        virtual void fill(uint8_t value, size_t count) = 0;


        /**
         * @brief Get %SPI interface settings.
         *
         * @return %SPI settings
         */
        const SPISettings & settings() const;


        /**
         * @brief Acquire usage rights to use the interface.
         *
         * Must be called before any I/O operations are executed.
         */
        virtual void acquire();
        /**
         * @brief Release usage rights for interface.
         *
         * Must be called after last I/O operation.
         */
        virtual void release();

    private:
        SPISettings settings_;  /**< %SPI settings */
        Mutex *     mutex_;	    /**< Mutex object */
    };
} // namespace sta


#endif // STA_CORE_SPI_SPI_HPP