static int cdns_wdt_probe()

in cadence_wdt.c [291:373]

• 68 lines of code
• 12 McCabe index (conditional complexity)

static int cdns_wdt_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	int ret, irq;
	unsigned long clock_f;
	struct cdns_wdt *wdt;
	struct watchdog_device *cdns_wdt_device;

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

	cdns_wdt_device = &wdt->cdns_wdt_device;
	cdns_wdt_device->info = &cdns_wdt_info;
	cdns_wdt_device->ops = &cdns_wdt_ops;
	cdns_wdt_device->timeout = CDNS_WDT_DEFAULT_TIMEOUT;
	cdns_wdt_device->min_timeout = CDNS_WDT_MIN_TIMEOUT;
	cdns_wdt_device->max_timeout = CDNS_WDT_MAX_TIMEOUT;

	wdt->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(wdt->regs))
		return PTR_ERR(wdt->regs);

	/* Register the interrupt */
	wdt->rst = of_property_read_bool(dev->of_node, "reset-on-timeout");
	irq = platform_get_irq(pdev, 0);
	if (!wdt->rst && irq >= 0) {
		ret = devm_request_irq(dev, irq, cdns_wdt_irq_handler, 0,
				       pdev->name, pdev);
		if (ret) {
			dev_err(dev,
				"cannot register interrupt handler err=%d\n",
				ret);
			return ret;
		}
	}

	/* Initialize the members of cdns_wdt structure */
	cdns_wdt_device->parent = dev;

	watchdog_init_timeout(cdns_wdt_device, wdt_timeout, dev);
	watchdog_set_nowayout(cdns_wdt_device, nowayout);
	watchdog_stop_on_reboot(cdns_wdt_device);
	watchdog_set_drvdata(cdns_wdt_device, wdt);

	wdt->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(wdt->clk))
		return dev_err_probe(dev, PTR_ERR(wdt->clk),
				     "input clock not found\n");

	ret = clk_prepare_enable(wdt->clk);
	if (ret) {
		dev_err(dev, "unable to enable clock\n");
		return ret;
	}
	ret = devm_add_action_or_reset(dev, cdns_clk_disable_unprepare,
				       wdt->clk);
	if (ret)
		return ret;

	clock_f = clk_get_rate(wdt->clk);
	if (clock_f <= CDNS_WDT_CLK_75MHZ) {
		wdt->prescaler = CDNS_WDT_PRESCALE_512;
		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
	} else {
		wdt->prescaler = CDNS_WDT_PRESCALE_4096;
		wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096;
	}

	spin_lock_init(&wdt->io_lock);

	watchdog_stop_on_reboot(cdns_wdt_device);
	watchdog_stop_on_unregister(cdns_wdt_device);
	ret = devm_watchdog_register_device(dev, cdns_wdt_device);
	if (ret)
		return ret;
	platform_set_drvdata(pdev, wdt);

	dev_info(dev, "Xilinx Watchdog Timer with timeout %ds%s\n",
		 cdns_wdt_device->timeout, nowayout ? ", nowayout" : "");

	return 0;
}