ENC28J60_WRITE_CTRL_REG
spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, data);
spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address, (u8) data);
spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, address + 1,
spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, ECON1, 0x00);