struct spi_ioc_transfer spi[length];
int i = 0;
int retVal = -1;
// one spi transfer for each byte
for (i = 0 ; i < length ; i++)
{
spi[i].tx_buf = (unsigned long)(data + i);
spi[i].rx_buf = (unsigned long)(data + i) ;
spi[i].len = sizeof(*(data + i)) ;
spi[i].delay_usecs = 0 ;
spi[i].speed_hz = ???; // <-- what to put here?
spi[i].bits_per_word = ???; // <-- what to put here?
spi[i].cs_change = 0;
}