r8a66597_write(r8a66597, TRCLR,
                                                td->pipe->pipetre);
                                r8a66597_write(r8a66597,
-                                               (urb->transfer_buffer_length
-                                               + td->maxpacket - 1)
-                                               / td->maxpacket,
+                                               DIV_ROUND_UP
+                                                 (urb->transfer_buffer_length,
+                                                  td->maxpacket),
                                                td->pipe->pipetrn);
                                r8a66597_bset(r8a66597, TRENB,
                                                td->pipe->pipetre);
 
                return NULL;
        maxp = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
        maxp *= 1 + (0x3 & (le16_to_cpu(desc->wMaxPacketSize) >> 11));
-       packets = (bytes + maxp - 1) / maxp;
+       packets = DIV_ROUND_UP(bytes, maxp);
 
        urb = usb_alloc_urb (packets, GFP_KERNEL);
        if (!urb)
 
        data_offset = priv->write_offset;
        if (data_offset > 0) {
                /* Subtract the control bytes */
-               countback -= (data_offset * ((countback + (PKTSZ - 1)) / PKTSZ));
+               countback -= (data_offset * DIV_ROUND_UP(countback, PKTSZ));
        }
        spin_lock_irqsave(&priv->tx_lock, flags);
        --priv->tx_outstanding_urbs;
 
        /* count data bytes, but not status bytes */
        countread = urb->actual_length;
-       countread -= 2 * ((countread + (PKTSZ - 1)) / PKTSZ);
+       countread -= 2 * DIV_ROUND_UP(countread, PKTSZ);
        spin_lock_irqsave(&priv->rx_lock, flags);
        priv->rx_bytes += countread;
        spin_unlock_irqrestore(&priv->rx_lock, flags);
 
        /* (TIIsTxActive doesn't seem to wait for the last byte) */
        if ((baud_rate=port->baud_rate) == 0)
                baud_rate = 50;
-       msleep(max(1,(10000+baud_rate-1)/baud_rate));
+       msleep(max(1, DIV_ROUND_UP(10000, baud_rate)));
 }
 
 static int TIChooseConfiguration (struct usb_device *dev)