spi.c

int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed) {

	uint32_t _speed;
	switch (speed) {
		case SPI_SPEED_100KHZ:
			_speed = 100000;
			break;
		case SPI_SPEED_400KHZ:
			_speed = 400000;
			break;
		case SPI_SPEED_1MHZ:
			_speed = 1000000;
			break;
		case SPI_SPEED_5MHZ:
			_speed = 5000000;
			break;
		case SPI_SPEED_10MHZ:
			_speed = 10000000;
			break;
	}

	uint32_t _dev;
	switch (dev) {
		case SPI_0:
			_dev = SSI0_BASE;
			break;
		case SPI_1:
			_dev = SSI1_BASE;
			break;
		case SPI_2:
			_dev = SSI2_BASE;
			break;
		case SPI_3:
			_dev = SSI3_BASE;
			break;
	}

	ROM_SSIConfigSetExpClk(_dev, ROM_SysCtlClockGet(), conf, SSI_MODE_MASTER, _speed, 8);
	ROM_SSIEnable(_dev);
}