static int mxs_lradc_probe()

in mxs-lradc.c [126:236]

• 94 lines of code
• 15 McCabe index (conditional complexity)

static int mxs_lradc_probe(struct platform_device *pdev)
{
	const struct of_device_id *of_id;
	struct device *dev = &pdev->dev;
	struct device_node *node = dev->of_node;
	struct mxs_lradc *lradc;
	struct mfd_cell *cells = NULL;
	struct resource *res;
	int ret = 0;
	u32 ts_wires = 0;

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

	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
	if (!of_id)
		return -EINVAL;

	lradc->soc = (enum mxs_lradc_id)of_id->data;

	lradc->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(lradc->clk)) {
		dev_err(dev, "Failed to get the delay unit clock\n");
		return PTR_ERR(lradc->clk);
	}

	ret = clk_prepare_enable(lradc->clk);
	if (ret) {
		dev_err(dev, "Failed to enable the delay unit clock\n");
		return ret;
	}

	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
					 &ts_wires);

	if (!ret) {
		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;

		switch (ts_wires) {
		case 4:
			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
			break;
		case 5:
			if (lradc->soc == IMX28_LRADC) {
				lradc->touchscreen_wire =
					MXS_LRADC_TOUCHSCREEN_5WIRE;
				break;
			}
			fallthrough;	/* to an error message for i.MX23 */
		default:
			dev_err(&pdev->dev,
				"Unsupported number of touchscreen wires (%d)\n"
				, ts_wires);
			ret = -EINVAL;
			goto err_clk;
		}
	} else {
		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
	}

	platform_set_drvdata(pdev, lradc);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		ret = -ENOMEM;
		goto err_clk;
	}

	switch (lradc->soc) {
	case IMX23_LRADC:
		mx23_adc_resources[RES_MEM] = *res;
		mx23_touchscreen_resources[RES_MEM] = *res;
		cells = mx23_cells;
		break;
	case IMX28_LRADC:
		mx28_adc_resources[RES_MEM] = *res;
		mx28_touchscreen_resources[RES_MEM] = *res;
		cells = mx28_cells;
		break;
	default:
		dev_err(dev, "Unsupported SoC\n");
		ret = -ENODEV;
		goto err_clk;
	}

	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
				   &cells[ADC_CELL], 1, NULL, 0, NULL);
	if (ret) {
		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
		goto err_clk;
	}

	if (!lradc->touchscreen_wire)
		return 0;

	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
				   &cells[TSC_CELL], 1, NULL, 0, NULL);
	if (ret) {
		dev_err(&pdev->dev,
			"Failed to add the touchscreen subdevice\n");
		goto err_clk;
	}

	return 0;

err_clk:
	clk_disable_unprepare(lradc->clk);

	return ret;
}