dmaengine: sun4i: Simplify error handling in probe()

Clean up error handling by using devm functions and dev_err_probe(). This
should make it easier to add new code, as we can eliminate the "goto
ladder" in sun4i_dma_probe().

Suggested-by: Chen-Yu Tsai <[e-mail]>
Reviewed-by: Jernej Skrabec <[e-mail]>
Acked-by: Chen-Yu Tsai <[e-mail]>
Reviewed-by: Julian Calaby <[e-mail]>
Signed-off-by: Bence Csókás <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/sun4i-dma.c

···
 	if (priv->irq < 0)
 		return priv->irq;
 
-	priv->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(priv->clk)) {
-		dev_err(&pdev->dev, "No clock specified\n");
-		return PTR_ERR(priv->clk);
-	}
+	priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
+				     "Couldn't start the clock\n");
 
 	if (priv->cfg->has_reset) {
 		priv->rst = devm_reset_control_get_exclusive_deasserted(&pdev->dev, NULL);
···
 		vchan_init(&vchan->vc, &priv->slave);
 	}
 
-	ret = clk_prepare_enable(priv->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "Couldn't enable the clock\n");
-		return ret;
-	}
-
 	/*
 	 * Make sure the IRQs are all disabled and accounted for. The bootloader
 	 * likes to leave these dirty
···
 
 	ret = devm_request_irq(&pdev->dev, priv->irq, sun4i_dma_interrupt,
 			       0, dev_name(&pdev->dev), priv);
-	if (ret) {
-		dev_err(&pdev->dev, "Cannot request IRQ\n");
-		goto err_clk_disable;
-	}
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Cannot request IRQ\n");
 
-	ret = dma_async_device_register(&priv->slave);
-	if (ret) {
-		dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
-		goto err_clk_disable;
-	}
+	ret = dmaenginem_async_device_register(&priv->slave);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Failed to register DMA engine device\n");
 
 	ret = of_dma_controller_register(pdev->dev.of_node, sun4i_dma_of_xlate,
 					 priv);
-	if (ret) {
-		dev_err(&pdev->dev, "of_dma_controller_register failed\n");
-		goto err_dma_unregister;
-	}
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Failed to register translation function\n");
 
 	dev_dbg(&pdev->dev, "Successfully probed SUN4I_DMA\n");
 
 	return 0;
-
-err_dma_unregister:
-	dma_async_device_unregister(&priv->slave);
-err_clk_disable:
-	clk_disable_unprepare(priv->clk);
-	return ret;
 }
 
 static void sun4i_dma_remove(struct platform_device *pdev)
···
 	disable_irq(priv->irq);
 
 	of_dma_controller_free(pdev->dev.of_node);
-	dma_async_device_unregister(&priv->slave);
-
-	clk_disable_unprepare(priv->clk);
 }
 
 static struct sun4i_dma_config sun4i_a10_dma_cfg = {