static int atmci_probe()

in host/atmel-mci.c [2449:2602]

• 128 lines of code
• 24 McCabe index (conditional complexity)

static int atmci_probe(struct platform_device *pdev)
{
	struct mci_platform_data	*pdata;
	struct atmel_mci		*host;
	struct resource			*regs;
	unsigned int			nr_slots;
	int				irq;
	int				ret, i;

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs)
		return -ENXIO;
	pdata = pdev->dev.platform_data;
	if (!pdata) {
		pdata = atmci_of_init(pdev);
		if (IS_ERR(pdata)) {
			dev_err(&pdev->dev, "platform data not available\n");
			return PTR_ERR(pdata);
		}
	}

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

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

	host->pdev = pdev;
	spin_lock_init(&host->lock);
	INIT_LIST_HEAD(&host->queue);

	host->mck = devm_clk_get(&pdev->dev, "mci_clk");
	if (IS_ERR(host->mck))
		return PTR_ERR(host->mck);

	host->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
	if (!host->regs)
		return -ENOMEM;

	ret = clk_prepare_enable(host->mck);
	if (ret)
		return ret;

	atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
	host->bus_hz = clk_get_rate(host->mck);

	host->mapbase = regs->start;

	tasklet_setup(&host->tasklet, atmci_tasklet_func);

	ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
	if (ret) {
		clk_disable_unprepare(host->mck);
		return ret;
	}

	/* Get MCI capabilities and set operations according to it */
	atmci_get_cap(host);
	ret = atmci_configure_dma(host);
	if (ret == -EPROBE_DEFER)
		goto err_dma_probe_defer;
	if (ret == 0) {
		host->prepare_data = &atmci_prepare_data_dma;
		host->submit_data = &atmci_submit_data_dma;
		host->stop_transfer = &atmci_stop_transfer_dma;
	} else if (host->caps.has_pdc) {
		dev_info(&pdev->dev, "using PDC\n");
		host->prepare_data = &atmci_prepare_data_pdc;
		host->submit_data = &atmci_submit_data_pdc;
		host->stop_transfer = &atmci_stop_transfer_pdc;
	} else {
		dev_info(&pdev->dev, "using PIO\n");
		host->prepare_data = &atmci_prepare_data;
		host->submit_data = &atmci_submit_data;
		host->stop_transfer = &atmci_stop_transfer;
	}

	platform_set_drvdata(pdev, host);

	timer_setup(&host->timer, atmci_timeout_timer, 0);

	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_DELAY);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	/* We need at least one slot to succeed */
	nr_slots = 0;
	ret = -ENODEV;
	if (pdata->slot[0].bus_width) {
		ret = atmci_init_slot(host, &pdata->slot[0],
				0, ATMCI_SDCSEL_SLOT_A, ATMCI_SDIOIRQA);
		if (!ret) {
			nr_slots++;
			host->buf_size = host->slot[0]->mmc->max_req_size;
		}
	}
	if (pdata->slot[1].bus_width) {
		ret = atmci_init_slot(host, &pdata->slot[1],
				1, ATMCI_SDCSEL_SLOT_B, ATMCI_SDIOIRQB);
		if (!ret) {
			nr_slots++;
			if (host->slot[1]->mmc->max_req_size > host->buf_size)
				host->buf_size =
					host->slot[1]->mmc->max_req_size;
		}
	}

	if (!nr_slots) {
		dev_err(&pdev->dev, "init failed: no slot defined\n");
		goto err_init_slot;
	}

	if (!host->caps.has_rwproof) {
		host->buffer = dma_alloc_coherent(&pdev->dev, host->buf_size,
		                                  &host->buf_phys_addr,
						  GFP_KERNEL);
		if (!host->buffer) {
			ret = -ENOMEM;
			dev_err(&pdev->dev, "buffer allocation failed\n");
			goto err_dma_alloc;
		}
	}

	dev_info(&pdev->dev,
			"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
			host->mapbase, irq, nr_slots);

	pm_runtime_mark_last_busy(&host->pdev->dev);
	pm_runtime_put_autosuspend(&pdev->dev);

	return 0;

err_dma_alloc:
	for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
		if (host->slot[i])
			atmci_cleanup_slot(host->slot[i], i);
	}
err_init_slot:
	clk_disable_unprepare(host->mck);

	pm_runtime_disable(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);

	del_timer_sync(&host->timer);
	if (!IS_ERR(host->dma.chan))
		dma_release_channel(host->dma.chan);
err_dma_probe_defer:
	free_irq(irq, host);
	return ret;
}