1 files changed, 66 insertions, 0 deletions
diff --git a/include/spi.h b/include/spi.h
new file mode 100644
index 0000000..8d51eb9
--- /dev/null
+++ b/include/spi.h
@@ -0,0 +1,66 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <stdint.h>
+
+#include "mcu/mcu_def.h"
+#include "tasks.h"
+
+#ifndef _IOE_SPI_H_
+#define _IOE_SPI_H_
+#ifdef CONFIG_SPI
+
+enum spiMode {
+    SPI_MODE_MASTER,
+    SPI_MODE_SLAVE
+};
+
+volatile extern int8_t _spi_busy;
+volatile extern Mutex spi_mutex;
+
+static inline void spi_init(enum spiMode mode) {
+    _spi_busy = 0;
+    if (mode == SPI_MODE_MASTER) {
+        // 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 master, set clock rate fck/16 and enable SPI interrupt
+        SPCR = _BV(SPE) | _BV(SPIE) | _BV(MSTR) | _BV(SPR0);
+    } else {
+        // 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 and interrupt
+        SPCR = _BV(SPE) | _BV(SPIE);
+    }
+}
+
+static inline int8_t spi_busy(void) {
+    return _spi_busy;
+}
+
+static inline void spi_join(void) {
+    task_delay_till(&_spi_busy, 0);
+}
+
+static inline void spi_transfer(uint8_t data) {
+    _spi_busy = 1;
+    SPDR = data;
+}
+
+static inline uint8_t spi_send(uint8_t data) {
+    spi_transfer(data);
+    task_delay_till(&_spi_busy, 0);
+    return SPDR;
+}
+
+static inline void spi_expose(uint8_t data) {
+    SPDR = data;
+}
+
+// Null terminated array
+extern void (*spi_receive)(uint8_t data);
+
+#endif /* CONFIG_SPI */
+#endif /* _IOE_SPI_H_ */