static int stm32_ipcc_probe()

in stm32-ipcc.c [203:331]

• 99 lines of code
• 17 McCabe index (conditional complexity)

static int stm32_ipcc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct stm32_ipcc *ipcc;
	unsigned long i;
	int ret;
	u32 ip_ver;
	static const char * const irq_name[] = {"rx", "tx"};
	irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq};

	if (!np) {
		dev_err(dev, "No DT found\n");
		return -ENODEV;
	}

	ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL);
	if (!ipcc)
		return -ENOMEM;

	spin_lock_init(&ipcc->lock);

	/* proc_id */
	if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
		dev_err(dev, "Missing st,proc-id\n");
		return -ENODEV;
	}

	if (ipcc->proc_id >= STM32_MAX_PROCS) {
		dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
		return -EINVAL;
	}

	/* regs */
	ipcc->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ipcc->reg_base))
		return PTR_ERR(ipcc->reg_base);

	ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;

	/* clock */
	ipcc->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(ipcc->clk))
		return PTR_ERR(ipcc->clk);

	ret = clk_prepare_enable(ipcc->clk);
	if (ret) {
		dev_err(dev, "can not enable the clock\n");
		return ret;
	}

	/* irq */
	for (i = 0; i < IPCC_IRQ_NUM; i++) {
		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
		if (ipcc->irqs[i] < 0) {
			ret = ipcc->irqs[i];
			goto err_clk;
		}

		ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL,
						irq_thread[i], IRQF_ONESHOT,
						dev_name(dev), ipcc);
		if (ret) {
			dev_err(dev, "failed to request irq %lu (%d)\n", i, ret);
			goto err_clk;
		}
	}

	/* mask and enable rx/tx irq */
	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
			    RX_BIT_MASK | TX_BIT_MASK);
	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR,
			    XCR_RXOIE | XCR_TXOIE);

	/* wakeup */
	if (of_property_read_bool(np, "wakeup-source")) {
		device_set_wakeup_capable(dev, true);

		ret = dev_pm_set_wake_irq(dev, ipcc->irqs[IPCC_IRQ_RX]);
		if (ret) {
			dev_err(dev, "Failed to set wake up irq\n");
			goto err_init_wkp;
		}
	}

	/* mailbox controller */
	ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR);
	ipcc->n_chans &= IPCFGR_CHAN_MASK;

	ipcc->controller.dev = dev;
	ipcc->controller.txdone_irq = true;
	ipcc->controller.ops = &stm32_ipcc_ops;
	ipcc->controller.num_chans = ipcc->n_chans;
	ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans,
					      sizeof(*ipcc->controller.chans),
					      GFP_KERNEL);
	if (!ipcc->controller.chans) {
		ret = -ENOMEM;
		goto err_irq_wkp;
	}

	for (i = 0; i < ipcc->controller.num_chans; i++)
		ipcc->controller.chans[i].con_priv = (void *)i;

	ret = devm_mbox_controller_register(dev, &ipcc->controller);
	if (ret)
		goto err_irq_wkp;

	platform_set_drvdata(pdev, ipcc);

	ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER);

	dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n",
		 FIELD_GET(VER_MAJREV_MASK, ip_ver),
		 FIELD_GET(VER_MINREV_MASK, ip_ver),
		 ipcc->controller.num_chans, ipcc->proc_id);

	clk_disable_unprepare(ipcc->clk);
	return 0;

err_irq_wkp:
	if (of_property_read_bool(np, "wakeup-source"))
		dev_pm_clear_wake_irq(dev);
err_init_wkp:
	device_set_wakeup_capable(dev, false);
err_clk:
	clk_disable_unprepare(ipcc->clk);
	return ret;
}