dmaengine: mpc512x: register for device tree channel lookup

Register the controller for device tree based lookup of DMA channels
(non-fatal for backwards compatibility with older device trees) and
provide the '#dma-cells' property in the shared mpc5121.dtsi file
Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

arch/powerpc/boot/dts/mpc5121.dtsi

@@ -498,6 +498,7 @@ dma0: dma@14000 {
 			compatible = "fsl,mpc5121-dma";
 			reg = <0x14000 0x1800>;
 			interrupts = <65 0x8>;
+			#dma-cells = <1>;
 		};
 	};
 

drivers/dma/mpc512x_dma.c

@@ -53,6 +53,7 @@
 #include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
+#include <linux/of_dma.h>
 #include <linux/of_platform.h>
 
 #include <linux/random.h>
@@ -1036,7 +1037,15 @@ static int mpc_dma_probe(struct platform_device *op)
 	if (retval)
 		goto err_free2;
 
-	return retval;
+	/* Register with OF helpers for DMA lookups (nonfatal) */
+	if (dev->of_node) {
+		retval = of_dma_controller_register(dev->of_node,
+						of_dma_xlate_by_chan_id, mdma);
+		if (retval)
+			dev_warn(dev, "Could not register for OF lookup\n");
+	}
+
+	return 0;
 
 err_free2:
 	if (mdma->is_mpc8308)
@@ -1057,6 +1066,8 @@ static int mpc_dma_remove(struct platform_device *op)
 	struct device *dev = &op->dev;
 	struct mpc_dma *mdma = dev_get_drvdata(dev);
 
+	if (dev->of_node)
+		of_dma_controller_free(dev->of_node);
 	dma_async_device_unregister(&mdma->dma);
 	if (mdma->is_mpc8308) {
 		free_irq(mdma->irq2, mdma);