+#ifdef CONFIG_SERIAL_8250_DMA
+ if (pdev->dev.of_node) {
+ /*
+ * Oh DMA support. If there are no DMA properties in the DT then
+ * we will fall back to a generic DMA channel which does not
+ * really work here. To ensure that we do not get a generic DMA
+ * channel assigned, we have the the_no_dma_filter_fn() here.
+ * To avoid "failed to request DMA" messages we check for DMA
+ * properties in DT.
+ */
+ ret = of_property_count_strings(pdev->dev.of_node, "dma-names");
+ if (ret == 2) {
+ up.dma = &priv->omap8250_dma;
+ up.port.handle_irq = omap_8250_dma_handle_irq;
+ priv->omap8250_dma.fn = the_no_dma_filter_fn;
+ priv->omap8250_dma.tx_dma = omap_8250_tx_dma;
+ priv->omap8250_dma.rx_dma = omap_8250_rx_dma;
+ priv->omap8250_dma.rx_size = RX_TRIGGER;
+ priv->omap8250_dma.rxconf.src_maxburst = RX_TRIGGER;
+ priv->omap8250_dma.txconf.dst_maxburst = TX_TRIGGER;
+
+ if (of_machine_is_compatible("ti,am33xx"))
+ priv->habit |= OMAP_DMA_TX_KICK;
+ }
+ }
+#endif