dmaengine: xilinx: Handle IRQ mapping errors

Handle errors when trying to map the IRQ for the DMA channels.

The main motivation here is to be able to handle probe deferral. E.g. when
using DT overlays it is possible that the DMA controller is probed before
interrupt controller, depending on the order in the DT.

In order to support this switch from irq_of_parse_and_map() to
of_irq_get(), which internally does the same, but it will return
EPROBE_DEFER when the interrupt controller is not yet available.

As a result other errors, such as an invalid IRQ specification, or missing
IRQ are also properly handled.

Signed-off-by: Lars-Peter Clausen <[e-mail]>
Reviewed-by: Radhey Shyam Pandey <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/xilinx/xilinx_dma.c

···
 	}
 
 	/* Request the interrupt */
-	chan->irq = irq_of_parse_and_map(node, chan->tdest);
+	chan->irq = of_irq_get(node, chan->tdest);
+	if (chan->irq < 0)
+		return dev_err_probe(xdev->dev, chan->irq, "failed to get irq\n");
 	err = request_irq(chan->irq, xdev->dma_config->irq_handler,
 			  IRQF_SHARED, "xilinx-dma-controller", chan);
 	if (err) {
···
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIMCDMA && ret < 0)
 		dev_warn(xdev->dev, "missing dma-channels property\n");
 
-	for (i = 0; i < nr_channels; i++)
-		xilinx_dma_chan_probe(xdev, node);
+	for (i = 0; i < nr_channels; i++) {
+		ret = xilinx_dma_chan_probe(xdev, node);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }