static int gpio_keys_polled_probe()

in keyboard/gpio_keys_polled.c [228:377]

• 118 lines of code
• 22 McCabe index (conditional complexity)

static int gpio_keys_polled_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct fwnode_handle *child = NULL;
	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
	struct gpio_keys_polled_dev *bdev;
	struct input_dev *input;
	int error;
	int i;

	if (!pdata) {
		pdata = gpio_keys_polled_get_devtree_pdata(dev);
		if (IS_ERR(pdata))
			return PTR_ERR(pdata);
	}

	if (!pdata->poll_interval) {
		dev_err(dev, "missing poll_interval value\n");
		return -EINVAL;
	}

	bdev = devm_kzalloc(dev, struct_size(bdev, data, pdata->nbuttons),
			    GFP_KERNEL);
	if (!bdev) {
		dev_err(dev, "no memory for private data\n");
		return -ENOMEM;
	}

	input = devm_input_allocate_device(dev);
	if (!input) {
		dev_err(dev, "no memory for input device\n");
		return -ENOMEM;
	}

	input_set_drvdata(input, bdev);

	input->name = pdata->name ?: pdev->name;
	input->phys = DRV_NAME"/input0";

	input->id.bustype = BUS_HOST;
	input->id.vendor = 0x0001;
	input->id.product = 0x0001;
	input->id.version = 0x0100;

	input->open = gpio_keys_polled_open;
	input->close = gpio_keys_polled_close;

	__set_bit(EV_KEY, input->evbit);
	if (pdata->rep)
		__set_bit(EV_REP, input->evbit);

	for (i = 0; i < pdata->nbuttons; i++) {
		const struct gpio_keys_button *button = &pdata->buttons[i];
		struct gpio_keys_button_data *bdata = &bdev->data[i];
		unsigned int type = button->type ?: EV_KEY;

		if (button->wakeup) {
			dev_err(dev, DRV_NAME " does not support wakeup\n");
			fwnode_handle_put(child);
			return -EINVAL;
		}

		if (!dev_get_platdata(dev)) {
			/* No legacy static platform data */
			child = device_get_next_child_node(dev, child);
			if (!child) {
				dev_err(dev, "missing child device node\n");
				return -EINVAL;
			}

			bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
							     NULL, GPIOD_IN,
							     button->desc);
			if (IS_ERR(bdata->gpiod)) {
				error = PTR_ERR(bdata->gpiod);
				if (error != -EPROBE_DEFER)
					dev_err(dev,
						"failed to get gpio: %d\n",
						error);
				fwnode_handle_put(child);
				return error;
			}
		} else if (gpio_is_valid(button->gpio)) {
			/*
			 * Legacy GPIO number so request the GPIO here and
			 * convert it to descriptor.
			 */
			unsigned flags = GPIOF_IN;

			if (button->active_low)
				flags |= GPIOF_ACTIVE_LOW;

			error = devm_gpio_request_one(dev, button->gpio,
					flags, button->desc ? : DRV_NAME);
			if (error) {
				dev_err(dev,
					"unable to claim gpio %u, err=%d\n",
					button->gpio, error);
				return error;
			}

			bdata->gpiod = gpio_to_desc(button->gpio);
			if (!bdata->gpiod) {
				dev_err(dev,
					"unable to convert gpio %u to descriptor\n",
					button->gpio);
				return -EINVAL;
			}
		}

		bdata->last_state = -1;
		bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
						pdata->poll_interval);

		input_set_capability(input, type, button->code);
		if (type == EV_ABS)
			gpio_keys_polled_set_abs_params(input, pdata,
							button->code);
	}

	fwnode_handle_put(child);

	bdev->input = input;
	bdev->dev = dev;
	bdev->pdata = pdata;

	error = input_setup_polling(input, gpio_keys_polled_poll);
	if (error) {
		dev_err(dev, "unable to set up polling, err=%d\n", error);
		return error;
	}

	input_set_poll_interval(input, pdata->poll_interval);

	error = input_register_device(input);
	if (error) {
		dev_err(dev, "unable to register polled device, err=%d\n",
			error);
		return error;
	}

	/* report initial state of the buttons */
	for (i = 0; i < pdata->nbuttons; i++)
		gpio_keys_polled_check_state(input, &pdata->buttons[i],
					     &bdev->data[i]);

	input_sync(input);

	return 0;
}