Added SPI implementation based on Linux library

include/sta/raspi/gpio_pin.hpp

@@ -31,10 +31,18 @@ namespace sta
 
         void setState(GpioPinState state) override;
 
+        static RaspiGpioPin DUMMY_GPIO;
+        
     private:
         uint8_t pin_;
         GpioMode mode_;
     };
+
+    class DummyGpioPin : RaspiGpioPin {
+        DummyGpioPin();
+
+        void setState(GpioPinState state) override;
+    }
 } // namespace sta
 
 #endif // STA_RASPI_GPIO_ENABLED

include/sta/raspi/hal.hpp

@@ -2,7 +2,7 @@
 #define STA_CORE_RASPI_HAL_HPP
 
 #include <wiringPi.h>
-#include <wiringPiSPI.h>
 #include <wiringPiI2C.h>
+#include <sys/ioctl.h>
 
 #endif //STA_CORE_RASPI_HAL_HPP

include/sta/raspi/spi.hpp

@@ -1,19 +1,50 @@
 #ifndef STA_CORE_RASPI_SPI_HPP
 #define STA_CORE_RASPI_SPI_HPP
 
+#include <sta/config.hpp>
+#ifdef STA_PLATFORM_RASPI
+
 #include <sta/spi/device.hpp>
+#include <sta/spi/spi.hpp>
 
 namespace sta 
 {
-    class RaspiSPI : SPI 
+    class RaspiSPI : public SPI 
     {
+    public:
+        RaspiSPI(const char * dev, const SPISettings & settings, Mutex * mutex = nullptr);
+        ~RaspiSPI();
 
+        void transfer(uint8_t value) override;
+        void transfer16(uint16_t value) override;
+        void transfer(const uint8_t * buffer, size_t size) override;
+        void transfer(const uint8_t * txBuffer, uint8_t * rxBuffer, size_t size) override;
+        void receive(uint8_t * buffer, size_t size) override;
+
+        void fill(uint8_t value, size_t count) override;
+
+        void acquire() override;
+        void release() override;
+
+    private:
+        char * spidev_;
+        int spifd_;
+        bool open_;
+
+        void update_setting(int setting, int value);
     };
 
     class RaspiSPIDevice : SPIDevice 
     {
+    public:
+        RaspiSPIDevice(RaspiSPI * intf);
 
+        void select() override;
+
+        void deselect() override;
     };
 } // namespace sta
 
+#endif // STA_PLATFORM_RASPI
+
 #endif // STA_CORE_RASPI_HPP