Expand the spi_nor_check() to make sure that nor->spimem and
nor->controller_ops are mutually exclusive.
Fixes: b35b9a10362d ("mtd: spi-nor: Move m25p80 code in spi-nor.c")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
 static int spi_nor_check(struct spi_nor *nor)
 {
        if (!nor->dev ||
+           (!nor->spimem && !nor->controller_ops) ||
            (!nor->spimem && nor->controller_ops &&
            (!nor->controller_ops->read ||
             !nor->controller_ops->write ||
                return -EINVAL;
        }
 
+       if (nor->spimem && nor->controller_ops) {
+               dev_err(nor->dev, "nor->spimem and nor->controller_ops are mutually exclusive, please set just one of them.\n");
+               return -EINVAL;
+       }
+
        return 0;
 }