static int bam_dma_probe()

in qcom/bam_dma.c [1244:1402]

• 124 lines of code
• 23 McCabe index (conditional complexity)

static int bam_dma_probe(struct platform_device *pdev)
{
	struct bam_device *bdev;
	const struct of_device_id *match;
	struct resource *iores;
	int ret, i;

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

	bdev->dev = &pdev->dev;

	match = of_match_node(bam_of_match, pdev->dev.of_node);
	if (!match) {
		dev_err(&pdev->dev, "Unsupported BAM module\n");
		return -ENODEV;
	}

	bdev->layout = match->data;

	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
	if (IS_ERR(bdev->regs))
		return PTR_ERR(bdev->regs);

	bdev->irq = platform_get_irq(pdev, 0);
	if (bdev->irq < 0)
		return bdev->irq;

	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
	if (ret) {
		dev_err(bdev->dev, "Execution environment unspecified\n");
		return ret;
	}

	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
						"qcom,controlled-remotely");
	bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
						"qcom,powered-remotely");

	if (bdev->controlled_remotely || bdev->powered_remotely) {
		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
					   &bdev->num_channels);
		if (ret)
			dev_err(bdev->dev, "num-channels unspecified in dt\n");

		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
					   &bdev->num_ees);
		if (ret)
			dev_err(bdev->dev, "num-ees unspecified in dt\n");
	}

	if (bdev->controlled_remotely || bdev->powered_remotely)
		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
	else
		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");

	if (IS_ERR(bdev->bamclk))
		return PTR_ERR(bdev->bamclk);

	ret = clk_prepare_enable(bdev->bamclk);
	if (ret) {
		dev_err(bdev->dev, "failed to prepare/enable clock\n");
		return ret;
	}

	ret = bam_init(bdev);
	if (ret)
		goto err_disable_clk;

	tasklet_setup(&bdev->task, dma_tasklet);

	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
				sizeof(*bdev->channels), GFP_KERNEL);

	if (!bdev->channels) {
		ret = -ENOMEM;
		goto err_tasklet_kill;
	}

	/* allocate and initialize channels */
	INIT_LIST_HEAD(&bdev->common.channels);

	for (i = 0; i < bdev->num_channels; i++)
		bam_channel_init(bdev, &bdev->channels[i], i);

	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
	if (ret)
		goto err_bam_channel_exit;

	/* set max dma segment size */
	bdev->common.dev = bdev->dev;
	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
	if (ret) {
		dev_err(bdev->dev, "cannot set maximum segment size\n");
		goto err_bam_channel_exit;
	}

	platform_set_drvdata(pdev, bdev);

	/* set capabilities */
	dma_cap_zero(bdev->common.cap_mask);
	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);

	/* initialize dmaengine apis */
	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
	bdev->common.device_free_chan_resources = bam_free_chan;
	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
	bdev->common.device_config = bam_slave_config;
	bdev->common.device_pause = bam_pause;
	bdev->common.device_resume = bam_resume;
	bdev->common.device_terminate_all = bam_dma_terminate_all;
	bdev->common.device_issue_pending = bam_issue_pending;
	bdev->common.device_tx_status = bam_tx_status;
	bdev->common.dev = bdev->dev;

	ret = dma_async_device_register(&bdev->common);
	if (ret) {
		dev_err(bdev->dev, "failed to register dma async device\n");
		goto err_bam_channel_exit;
	}

	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
					&bdev->common);
	if (ret)
		goto err_unregister_dma;

	if (!bdev->bamclk) {
		pm_runtime_disable(&pdev->dev);
		return 0;
	}

	pm_runtime_irq_safe(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_mark_last_busy(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	return 0;

err_unregister_dma:
	dma_async_device_unregister(&bdev->common);
err_bam_channel_exit:
	for (i = 0; i < bdev->num_channels; i++)
		tasklet_kill(&bdev->channels[i].vc.task);
err_tasklet_kill:
	tasklet_kill(&bdev->task);
err_disable_clk:
	clk_disable_unprepare(bdev->bamclk);

	return ret;
}