media: hantro: add fallback handling for single irq/clk

Currently the driver expects that each irq/clk will have a name
specified.

A valid point was raised by the DT maintainers - when there is a single
interrupt line or clock - the names are not needed.

Keep the names within the drivers themselves, but don't use them when
only a single entry exists. Instead use:
 - num_clk == 1 - devm_clk_get(..., NULL)
 - num_irq == 1 - platform_get_irq(..., 0)
Suggested-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/hantro/hantro_drv.c

@@ -763,12 +763,23 @@ static int hantro_probe(struct platform_device *pdev)
 	if (!vpu->clocks)
 		return -ENOMEM;
 
-	for (i = 0; i < vpu->variant->num_clocks; i++)
-		vpu->clocks[i].id = vpu->variant->clk_names[i];
-	ret = devm_clk_bulk_get(&pdev->dev, vpu->variant->num_clocks,
-				vpu->clocks);
-	if (ret)
-		return ret;
+	if (vpu->variant->num_clocks > 1) {
+		for (i = 0; i < vpu->variant->num_clocks; i++)
+			vpu->clocks[i].id = vpu->variant->clk_names[i];
+
+		ret = devm_clk_bulk_get(&pdev->dev, vpu->variant->num_clocks,
+					vpu->clocks);
+		if (ret)
+			return ret;
+	} else {
+		/*
+		 * If the driver has a single clk, chances are there will be no
+		 * actual name in the DT bindings.
+		 */
+		vpu->clocks[0].clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(vpu->clocks))
+			return PTR_ERR(vpu->clocks);
+	}
 
 	num_bases = vpu->variant->num_regs ?: 1;
 	vpu->reg_bases = devm_kcalloc(&pdev->dev, num_bases,
@@ -796,13 +807,23 @@ static int hantro_probe(struct platform_device *pdev)
 	vb2_dma_contig_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
 
 	for (i = 0; i < vpu->variant->num_irqs; i++) {
-		const char *irq_name = vpu->variant->irqs[i].name;
+		const char *irq_name;
 		int irq;
 
 		if (!vpu->variant->irqs[i].handler)
 			continue;
 
-		irq = platform_get_irq_byname(vpu->pdev, irq_name);
+		if (vpu->variant->num_clocks > 1) {
+			irq_name = vpu->variant->irqs[i].name;
+			irq = platform_get_irq_byname(vpu->pdev, irq_name);
+		} else {
+			/*
+			 * If the driver has a single IRQ, chances are there
+			 * will be no actual name in the DT bindings.
+			 */
+			irq_name = "default";
+			irq = platform_get_irq(vpu->pdev, 0);
+		}
 		if (irq <= 0)
 			return -ENXIO;