static int mtk_cqdma_probe()

in mediatek/mtk-cqdma.c [749:891]

• 114 lines of code
• 19 McCabe index (conditional complexity)

static int mtk_cqdma_probe(struct platform_device *pdev)
{
	struct mtk_cqdma_device *cqdma;
	struct mtk_cqdma_vchan *vc;
	struct dma_device *dd;
	struct resource *res;
	int err;
	u32 i;

	cqdma = devm_kzalloc(&pdev->dev, sizeof(*cqdma), GFP_KERNEL);
	if (!cqdma)
		return -ENOMEM;

	dd = &cqdma->ddev;

	cqdma->clk = devm_clk_get(&pdev->dev, "cqdma");
	if (IS_ERR(cqdma->clk)) {
		dev_err(&pdev->dev, "No clock for %s\n",
			dev_name(&pdev->dev));
		return PTR_ERR(cqdma->clk);
	}

	dma_cap_set(DMA_MEMCPY, dd->cap_mask);

	dd->copy_align = MTK_CQDMA_ALIGN_SIZE;
	dd->device_alloc_chan_resources = mtk_cqdma_alloc_chan_resources;
	dd->device_free_chan_resources = mtk_cqdma_free_chan_resources;
	dd->device_tx_status = mtk_cqdma_tx_status;
	dd->device_issue_pending = mtk_cqdma_issue_pending;
	dd->device_prep_dma_memcpy = mtk_cqdma_prep_dma_memcpy;
	dd->device_terminate_all = mtk_cqdma_terminate_all;
	dd->src_addr_widths = MTK_CQDMA_DMA_BUSWIDTHS;
	dd->dst_addr_widths = MTK_CQDMA_DMA_BUSWIDTHS;
	dd->directions = BIT(DMA_MEM_TO_MEM);
	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
	dd->dev = &pdev->dev;
	INIT_LIST_HEAD(&dd->channels);

	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
						      "dma-requests",
						      &cqdma->dma_requests)) {
		dev_info(&pdev->dev,
			 "Using %u as missing dma-requests property\n",
			 MTK_CQDMA_NR_VCHANS);

		cqdma->dma_requests = MTK_CQDMA_NR_VCHANS;
	}

	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
						      "dma-channels",
						      &cqdma->dma_channels)) {
		dev_info(&pdev->dev,
			 "Using %u as missing dma-channels property\n",
			 MTK_CQDMA_NR_PCHANS);

		cqdma->dma_channels = MTK_CQDMA_NR_PCHANS;
	}

	cqdma->pc = devm_kcalloc(&pdev->dev, cqdma->dma_channels,
				 sizeof(*cqdma->pc), GFP_KERNEL);
	if (!cqdma->pc)
		return -ENOMEM;

	/* initialization for PCs */
	for (i = 0; i < cqdma->dma_channels; ++i) {
		cqdma->pc[i] = devm_kcalloc(&pdev->dev, 1,
					    sizeof(**cqdma->pc), GFP_KERNEL);
		if (!cqdma->pc[i])
			return -ENOMEM;

		INIT_LIST_HEAD(&cqdma->pc[i]->queue);
		spin_lock_init(&cqdma->pc[i]->lock);
		refcount_set(&cqdma->pc[i]->refcnt, 0);
		cqdma->pc[i]->base = devm_platform_ioremap_resource(pdev, i);
		if (IS_ERR(cqdma->pc[i]->base))
			return PTR_ERR(cqdma->pc[i]->base);

		/* allocate IRQ resource */
		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
		if (!res) {
			dev_err(&pdev->dev, "No irq resource for %s\n",
				dev_name(&pdev->dev));
			return -EINVAL;
		}
		cqdma->pc[i]->irq = res->start;

		err = devm_request_irq(&pdev->dev, cqdma->pc[i]->irq,
				       mtk_cqdma_irq, 0, dev_name(&pdev->dev),
				       cqdma);
		if (err) {
			dev_err(&pdev->dev,
				"request_irq failed with err %d\n", err);
			return -EINVAL;
		}
	}

	/* allocate resource for VCs */
	cqdma->vc = devm_kcalloc(&pdev->dev, cqdma->dma_requests,
				 sizeof(*cqdma->vc), GFP_KERNEL);
	if (!cqdma->vc)
		return -ENOMEM;

	for (i = 0; i < cqdma->dma_requests; i++) {
		vc = &cqdma->vc[i];
		vc->vc.desc_free = mtk_cqdma_vdesc_free;
		vchan_init(&vc->vc, dd);
		init_completion(&vc->issue_completion);
	}

	err = dma_async_device_register(dd);
	if (err)
		return err;

	err = of_dma_controller_register(pdev->dev.of_node,
					 of_dma_xlate_by_chan_id, cqdma);
	if (err) {
		dev_err(&pdev->dev,
			"MediaTek CQDMA OF registration failed %d\n", err);
		goto err_unregister;
	}

	err = mtk_cqdma_hw_init(cqdma);
	if (err) {
		dev_err(&pdev->dev,
			"MediaTek CQDMA HW initialization failed %d\n", err);
		goto err_unregister;
	}

	platform_set_drvdata(pdev, cqdma);

	/* initialize tasklet for each PC */
	for (i = 0; i < cqdma->dma_channels; ++i)
		tasklet_setup(&cqdma->pc[i]->tasklet, mtk_cqdma_tasklet_cb);

	dev_info(&pdev->dev, "MediaTek CQDMA driver registered\n");

	return 0;

err_unregister:
	dma_async_device_unregister(dd);

	return err;
}