static int __init sh_rtc_probe()

in rtc-sh.c [468:621]

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

static int __init sh_rtc_probe(struct platform_device *pdev)
{
	struct sh_rtc *rtc;
	struct resource *res;
	char clk_name[6];
	int clk_id, ret;

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

	spin_lock_init(&rtc->lock);

	/* get periodic/carry/alarm irqs */
	ret = platform_get_irq(pdev, 0);
	if (unlikely(ret <= 0)) {
		dev_err(&pdev->dev, "No IRQ resource\n");
		return -ENOENT;
	}

	rtc->periodic_irq = ret;
	rtc->carry_irq = platform_get_irq(pdev, 1);
	rtc->alarm_irq = platform_get_irq(pdev, 2);

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res)
		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (unlikely(res == NULL)) {
		dev_err(&pdev->dev, "No IO resource\n");
		return -ENOENT;
	}

	rtc->regsize = resource_size(res);

	rtc->res = devm_request_mem_region(&pdev->dev, res->start,
					rtc->regsize, pdev->name);
	if (unlikely(!rtc->res))
		return -EBUSY;

	rtc->regbase = devm_ioremap(&pdev->dev, rtc->res->start, rtc->regsize);
	if (unlikely(!rtc->regbase))
		return -EINVAL;

	if (!pdev->dev.of_node) {
		clk_id = pdev->id;
		/* With a single device, the clock id is still "rtc0" */
		if (clk_id < 0)
			clk_id = 0;

		snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
	} else
		snprintf(clk_name, sizeof(clk_name), "fck");

	rtc->clk = devm_clk_get(&pdev->dev, clk_name);
	if (IS_ERR(rtc->clk)) {
		/*
		 * No error handling for rtc->clk intentionally, not all
		 * platforms will have a unique clock for the RTC, and
		 * the clk API can handle the struct clk pointer being
		 * NULL.
		 */
		rtc->clk = NULL;
	}

	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtc->rtc_dev))
		return PTR_ERR(rtc->rtc_dev);

	clk_enable(rtc->clk);

	rtc->capabilities = RTC_DEF_CAPABILITIES;

#ifdef CONFIG_SUPERH
	if (dev_get_platdata(&pdev->dev)) {
		struct sh_rtc_platform_info *pinfo =
			dev_get_platdata(&pdev->dev);

		/*
		 * Some CPUs have special capabilities in addition to the
		 * default set. Add those in here.
		 */
		rtc->capabilities |= pinfo->capabilities;
	}
#endif

	if (rtc->carry_irq <= 0) {
		/* register shared periodic/carry/alarm irq */
		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
				sh_rtc_shared, 0, "sh-rtc", rtc);
		if (unlikely(ret)) {
			dev_err(&pdev->dev,
				"request IRQ failed with %d, IRQ %d\n", ret,
				rtc->periodic_irq);
			goto err_unmap;
		}
	} else {
		/* register periodic/carry/alarm irqs */
		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
				sh_rtc_periodic, 0, "sh-rtc period", rtc);
		if (unlikely(ret)) {
			dev_err(&pdev->dev,
				"request period IRQ failed with %d, IRQ %d\n",
				ret, rtc->periodic_irq);
			goto err_unmap;
		}

		ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
				sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
		if (unlikely(ret)) {
			dev_err(&pdev->dev,
				"request carry IRQ failed with %d, IRQ %d\n",
				ret, rtc->carry_irq);
			goto err_unmap;
		}

		ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
				sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
		if (unlikely(ret)) {
			dev_err(&pdev->dev,
				"request alarm IRQ failed with %d, IRQ %d\n",
				ret, rtc->alarm_irq);
			goto err_unmap;
		}
	}

	platform_set_drvdata(pdev, rtc);

	/* everything disabled by default */
	sh_rtc_setaie(&pdev->dev, 0);
	sh_rtc_setcie(&pdev->dev, 0);

	rtc->rtc_dev->ops = &sh_rtc_ops;
	rtc->rtc_dev->max_user_freq = 256;

	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
		rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900;
		rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_9999;
	} else {
		rtc->rtc_dev->range_min = mktime64(1999, 1, 1, 0, 0, 0);
		rtc->rtc_dev->range_max = mktime64(2098, 12, 31, 23, 59, 59);
	}

	ret = devm_rtc_register_device(rtc->rtc_dev);
	if (ret)
		goto err_unmap;

	device_init_wakeup(&pdev->dev, 1);
	return 0;

err_unmap:
	clk_disable(rtc->clk);

	return ret;
}