Re: [PATCH v5 2/4] [media] exynos-scaler: Add core functionality for the SCALER driver

+static int scaler_probe(struct platform_device *pdev)
+{
+	struct scaler_dev *scaler;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	scaler = devm_kzalloc(dev, sizeof(*scaler), GFP_KERNEL);
+	if (!scaler)
+		return -ENOMEM;
+
+	scaler->pdev = pdev;
+	scaler->variant = scaler_get_variant_data(pdev);
+
+	init_waitqueue_head(&scaler->irq_queue);
+	spin_lock_init(&scaler->slock);
+	mutex_init(&scaler->lock);
+	scaler->clock = ERR_PTR(-EINVAL);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	scaler->regs = devm_request_and_ioremap(dev, res);
+	if (!scaler->regs)
+		return -ENODEV;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev, "failed to get IRQ resource\n");
+		return -ENXIO;
+	}
+
+	ret = scaler_clk_get(scaler);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_request_irq(dev, res->start, scaler_irq_handler,
+				0, pdev->name, scaler);
+	if (ret < 0) {
+		dev_err(dev, "failed to install irq (%d)\n", ret);
+		goto err_clk;
+	}
+
+	platform_set_drvdata(pdev, scaler);
+	pm_runtime_enable(dev);
+
+	/* Initialize the continious memory allocator */
+	scaler->alloc_ctx = vb2_dma_contig_init_ctx(dev);
+	if (IS_ERR(scaler->alloc_ctx)) {
+		ret = PTR_ERR(scaler->alloc_ctx);
+		goto err_clk;
+	}
+
+	ret = v4l2_device_register(dev, &scaler->v4l2_dev);
+	if (ret < 0)
+		goto err_clk;
+
+	ret = scaler_register_m2m_device(scaler);
+	if (ret < 0)
+		goto err_v4l2;
+
+	dev_info(dev, "registered successfully\n");
+	return 0;
+
+err_v4l2:
+	v4l2_device_unregister(&scaler->v4l2_dev);
+err_clk:
+	scaler_clk_put(scaler);

+	return ret;
+}
+
+static int scaler_remove(struct platform_device *pdev)
+{
+	struct scaler_dev *scaler = platform_get_drvdata(pdev);
+
+	scaler_unregister_m2m_device(scaler);
+	v4l2_device_unregister(&scaler->v4l2_dev);
+
+	vb2_dma_contig_cleanup_ctx(scaler->alloc_ctx);
+	pm_runtime_disable(&pdev->dev);
+	scaler_clk_put(scaler);
+
+	scaler_dbg(scaler, "%s driver unloaded\n", pdev->name);
+	return 0;
+}