1 files changed, 47 insertions, 0 deletions
diff --git a/src/spi.c b/src/spi.c
new file mode 100644
index 0000000..8462905
--- /dev/null
+++ b/src/spi.c
@@ -0,0 +1,47 @@
+#include "../spi.h"
+#include "mcu/mcu.h"
+
+inline void ioe_spi_join(void) {
+    // TODO
+}
+
+inline int ioe_spi_bussy(void) {
+}
+
+#ifdef IOE_SPI_MASTER
+inline void ioe_spi_init(void) {
+    // Set MOSI and SCK output
+    DDR_SPI |= _BV(DD_MOSI) | _BV(DD_SCLK);
+    // Set MISO pull up resistor
+    PORT_SPI |= _BV(PORT_MISO);
+    // Enable SPI interrupt
+    SPCR |= _BV(SPIE);
+    // Enable SPI master and set clock rate fck/16
+    SPCR = _BV(SPE) | _BV(MSTR) | _BV(SPR0);
+}
+
+inline void ioe_spi_transfer(int8_t data) {
+    SPDR = data;
+}
+
+#else /* IOE_SPI_MASTER */
+inline void ioe_spi_init(void) {
+    // Set MISO as output
+    DDR_SPI = _BV(DD_MISO);
+    // Set SCLK and MOSI pull up resistor
+    PORT_SPI |= _BV(PORT_SCLK) | _BV(PORT_MOSI);
+    // Enable SPI interrupt
+    SPCR |= _BV(SPIE);
+    // Enable SPI
+    SPCR = _BV(SPE);
+}
+
+inline void ioe_spi_expose(int8_t data) {
+    SPDR = data;
+}
+
+#endif /* IOE_SPI_MASTER */
+
+SIGNAL(SPI_STC_vect) {
+    ioe_spi_retrieve(SPDR);
+}