static int twl_rtc_probe()

in rtc-twl.c [492:583]

• 73 lines of code
• 16 McCabe index (conditional complexity)

static int twl_rtc_probe(struct platform_device *pdev)
{
	struct twl_rtc *twl_rtc;
	struct device_node *np = pdev->dev.of_node;
	int ret = -EINVAL;
	int irq = platform_get_irq(pdev, 0);
	u8 rd_reg;

	if (!np) {
		dev_err(&pdev->dev, "no DT info\n");
		return -EINVAL;
	}

	if (irq <= 0)
		return ret;

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

	if (twl_class_is_4030()) {
		twl_rtc->class = TWL_4030;
		twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map;
	} else if (twl_class_is_6030()) {
		twl_rtc->class = TWL_6030;
		twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map;
	} else {
		dev_err(&pdev->dev, "TWL Class not supported.\n");
		return -EINVAL;
	}

	ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG);
	if (ret < 0)
		return ret;

	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
		dev_warn(&pdev->dev, "Power up reset detected.\n");

	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
		dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");

	/* Clear RTC Power up reset and pending alarm interrupts */
	ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG);
	if (ret < 0)
		return ret;

	if (twl_rtc->class == TWL_6030) {
		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
			REG_INT_MSK_LINE_A);
		twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
			REG_INT_MSK_STS_A);
	}

	dev_info(&pdev->dev, "Enabling TWL-RTC\n");
	ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M,
			       REG_RTC_CTRL_REG);
	if (ret < 0)
		return ret;

	/* ensure interrupts are disabled, bootloaders can be strange */
	ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG);
	if (ret < 0)
		dev_warn(&pdev->dev, "unable to disable interrupt\n");

	/* init cached IRQ enable bits */
	ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits,
			      REG_RTC_INTERRUPTS_REG);
	if (ret < 0)
		return ret;

	platform_set_drvdata(pdev, twl_rtc);
	device_init_wakeup(&pdev->dev, 1);

	twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
					&twl_rtc_ops, THIS_MODULE);
	if (IS_ERR(twl_rtc->rtc)) {
		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
			PTR_ERR(twl_rtc->rtc));
		return PTR_ERR(twl_rtc->rtc);
	}

	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
					twl_rtc_interrupt,
					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
					dev_name(&twl_rtc->rtc->dev), twl_rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "IRQ is not free.\n");
		return ret;
	}

	return 0;
}