static int rockchip_saradc_probe()

in adc/rockchip_saradc.c [317:482]

• 130 lines of code
• 25 McCabe index (conditional complexity)

static int rockchip_saradc_probe(struct platform_device *pdev)
{
	struct rockchip_saradc *info = NULL;
	struct device_node *np = pdev->dev.of_node;
	struct iio_dev *indio_dev = NULL;
	const struct of_device_id *match;
	int ret;
	int irq;

	if (!np)
		return -ENODEV;

	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
	if (!indio_dev) {
		dev_err(&pdev->dev, "failed allocating iio device\n");
		return -ENOMEM;
	}
	info = iio_priv(indio_dev);

	match = of_match_device(rockchip_saradc_match, &pdev->dev);
	if (!match) {
		dev_err(&pdev->dev, "failed to match device\n");
		return -ENODEV;
	}

	info->data = match->data;

	/* Sanity check for possible later IP variants with more channels */
	if (info->data->num_channels > SARADC_MAX_CHANNELS) {
		dev_err(&pdev->dev, "max channels exceeded");
		return -EINVAL;
	}

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

	/*
	 * The reset should be an optional property, as it should work
	 * with old devicetrees as well
	 */
	info->reset = devm_reset_control_get_exclusive(&pdev->dev,
						       "saradc-apb");
	if (IS_ERR(info->reset)) {
		ret = PTR_ERR(info->reset);
		if (ret != -ENOENT)
			return dev_err_probe(&pdev->dev, ret,
					     "failed to get saradc-apb\n");

		dev_dbg(&pdev->dev, "no reset control found\n");
		info->reset = NULL;
	}

	init_completion(&info->completion);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return dev_err_probe(&pdev->dev, irq, "failed to get irq\n");

	ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr,
			       0, dev_name(&pdev->dev), info);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed requesting irq %d\n", irq);
		return ret;
	}

	info->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(info->pclk))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->pclk),
				     "failed to get pclk\n");

	info->clk = devm_clk_get(&pdev->dev, "saradc");
	if (IS_ERR(info->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
				     "failed to get adc clock\n");

	info->vref = devm_regulator_get(&pdev->dev, "vref");
	if (IS_ERR(info->vref))
		return dev_err_probe(&pdev->dev, PTR_ERR(info->vref),
				     "failed to get regulator\n");

	if (info->reset)
		rockchip_saradc_reset_controller(info->reset);

	/*
	 * Use a default value for the converter clock.
	 * This may become user-configurable in the future.
	 */
	ret = clk_set_rate(info->clk, info->data->clk_rate);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
		return ret;
	}

	ret = regulator_enable(info->vref);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable vref regulator\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_regulator_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	ret = regulator_get_voltage(info->vref);
	if (ret < 0)
		return ret;

	info->uv_vref = ret;

	ret = clk_prepare_enable(info->pclk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable pclk\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_pclk_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	ret = clk_prepare_enable(info->clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable converter clock\n");
		return ret;
	}
	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_clk_disable, info);
	if (ret) {
		dev_err(&pdev->dev, "failed to register devm action, %d\n",
			ret);
		return ret;
	}

	platform_set_drvdata(pdev, indio_dev);

	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->info = &rockchip_saradc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = info->data->channels;
	indio_dev->num_channels = info->data->num_channels;
	ret = devm_iio_triggered_buffer_setup(&indio_dev->dev, indio_dev, NULL,
					      rockchip_saradc_trigger_handler,
					      NULL);
	if (ret)
		return ret;

	info->nb.notifier_call = rockchip_saradc_volt_notify;
	ret = regulator_register_notifier(info->vref, &info->nb);
	if (ret)
		return ret;

	ret = devm_add_action_or_reset(&pdev->dev,
				       rockchip_saradc_regulator_unreg_notifier,
				       info);
	if (ret)
		return ret;

	return devm_iio_device_register(&pdev->dev, indio_dev);
}