static int mtk_i2c_probe()

in busses/i2c-mt65xx.c [1280:1400]

• 101 lines of code
• 21 McCabe index (conditional complexity)

static int mtk_i2c_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct mtk_i2c *i2c;
	struct clk *clk;
	struct resource *res;
	int irq;

	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
	if (!i2c)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	i2c->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(i2c->base))
		return PTR_ERR(i2c->base);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(i2c->pdmabase))
		return PTR_ERR(i2c->pdmabase);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	init_completion(&i2c->msg_complete);

	i2c->dev_comp = of_device_get_match_data(&pdev->dev);
	i2c->adap.dev.of_node = pdev->dev.of_node;
	i2c->dev = &pdev->dev;
	i2c->adap.dev.parent = &pdev->dev;
	i2c->adap.owner = THIS_MODULE;
	i2c->adap.algo = &mtk_i2c_algorithm;
	i2c->adap.quirks = i2c->dev_comp->quirks;
	i2c->adap.timeout = 2 * HZ;
	i2c->adap.retries = 1;
	i2c->adap.bus_regulator = devm_regulator_get_optional(&pdev->dev, "vbus");
	if (IS_ERR(i2c->adap.bus_regulator)) {
		if (PTR_ERR(i2c->adap.bus_regulator) == -ENODEV)
			i2c->adap.bus_regulator = NULL;
		else
			return PTR_ERR(i2c->adap.bus_regulator);
	}

	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
	if (ret)
		return -EINVAL;

	if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
		return -EINVAL;

	i2c->clk_main = devm_clk_get(&pdev->dev, "main");
	if (IS_ERR(i2c->clk_main)) {
		dev_err(&pdev->dev, "cannot get main clock\n");
		return PTR_ERR(i2c->clk_main);
	}

	i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
	if (IS_ERR(i2c->clk_dma)) {
		dev_err(&pdev->dev, "cannot get dma clock\n");
		return PTR_ERR(i2c->clk_dma);
	}

	i2c->clk_arb = devm_clk_get(&pdev->dev, "arb");
	if (IS_ERR(i2c->clk_arb))
		i2c->clk_arb = NULL;

	clk = i2c->clk_main;
	if (i2c->have_pmic) {
		i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
		if (IS_ERR(i2c->clk_pmic)) {
			dev_err(&pdev->dev, "cannot get pmic clock\n");
			return PTR_ERR(i2c->clk_pmic);
		}
		clk = i2c->clk_pmic;
	}

	strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));

	ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
	if (ret) {
		dev_err(&pdev->dev, "Failed to set the speed.\n");
		return -EINVAL;
	}

	if (i2c->dev_comp->max_dma_support > 32) {
		ret = dma_set_mask(&pdev->dev,
				DMA_BIT_MASK(i2c->dev_comp->max_dma_support));
		if (ret) {
			dev_err(&pdev->dev, "dma_set_mask return error.\n");
			return ret;
		}
	}

	ret = mtk_i2c_clock_enable(i2c);
	if (ret) {
		dev_err(&pdev->dev, "clock enable failed!\n");
		return ret;
	}
	mtk_i2c_init_hw(i2c);
	mtk_i2c_clock_disable(i2c);

	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
			       IRQF_NO_SUSPEND | IRQF_TRIGGER_NONE,
			       dev_name(&pdev->dev), i2c);
	if (ret < 0) {
		dev_err(&pdev->dev,
			"Request I2C IRQ %d fail\n", irq);
		return ret;
	}

	i2c_set_adapdata(&i2c->adap, i2c);
	ret = i2c_add_adapter(&i2c->adap);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, i2c);

	return 0;
}