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#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdint.h>
#include "mcu/mcu_def.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;
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) {
while(!_spi_busy) ;
}
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);
spi_join();
return SPDR;
}
static inline void spi_expose(uint8_t data) {
SPDR = data;
}
extern void (*spi_receive)(uint8_t data);
#endif /* CONFIG_SPI */
#endif /* _IOE_SPI_H_ */
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