static int gpio_extcon_probe()

in extcon-gpio.c [65:135]

• 42 lines of code
• 10 McCabe index (conditional complexity)

static int gpio_extcon_probe(struct platform_device *pdev)
{
	struct gpio_extcon_data *data;
	struct device *dev = &pdev->dev;
	unsigned long irq_flags;
	int irq;
	int ret;

	data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	/*
	 * FIXME: extcon_id represents the unique identifier of external
	 * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id
	 * is necessary to register the extcon device. But, it's not yet
	 * developed to get the extcon id from device-tree or others.
	 * On later, it have to be solved.
	 */
	if (data->extcon_id > EXTCON_NONE)
		return -EINVAL;

	data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);
	if (IS_ERR(data->gpiod))
		return PTR_ERR(data->gpiod);
	irq = gpiod_to_irq(data->gpiod);
	if (irq <= 0)
		return irq;

	/*
	 * It is unlikely that this is an acknowledged interrupt that goes
	 * away after handling, what we are looking for are falling edges
	 * if the signal is active low, and rising edges if the signal is
	 * active high.
	 */
	if (gpiod_is_active_low(data->gpiod))
		irq_flags = IRQF_TRIGGER_FALLING;
	else
		irq_flags = IRQF_TRIGGER_RISING;

	/* Allocate the memory of extcon devie and register extcon device */
	data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id);
	if (IS_ERR(data->edev)) {
		dev_err(dev, "failed to allocate extcon device\n");
		return -ENOMEM;
	}

	ret = devm_extcon_dev_register(dev, data->edev);
	if (ret < 0)
		return ret;

	ret = devm_delayed_work_autocancel(dev, &data->work, gpio_extcon_work);
	if (ret)
		return ret;

	/*
	 * Request the interrupt of gpio to detect whether external connector
	 * is attached or detached.
	 */
	ret = devm_request_any_context_irq(dev, irq,
					gpio_irq_handler, irq_flags,
					pdev->name, data);
	if (ret < 0)
		return ret;

	platform_set_drvdata(pdev, data);
	/* Perform initial detection */
	gpio_extcon_work(&data->work.work);

	return 0;
}