static int s3c24xx_i2c_probe()

in busses/i2c-s3c2410.c [1049:1185]

• 99 lines of code
• 18 McCabe index (conditional complexity)

static int s3c24xx_i2c_probe(struct platform_device *pdev)
{
	struct s3c24xx_i2c *i2c;
	struct s3c2410_platform_i2c *pdata = NULL;
	struct resource *res;
	int ret;

	if (!pdev->dev.of_node) {
		pdata = dev_get_platdata(&pdev->dev);
		if (!pdata) {
			dev_err(&pdev->dev, "no platform data\n");
			return -EINVAL;
		}
	}

	i2c = devm_kzalloc(&pdev->dev, sizeof(struct s3c24xx_i2c), GFP_KERNEL);
	if (!i2c)
		return -ENOMEM;

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

	i2c->quirks = s3c24xx_get_device_quirks(pdev);
	i2c->sysreg = ERR_PTR(-ENOENT);
	if (pdata)
		memcpy(i2c->pdata, pdata, sizeof(*pdata));
	else
		s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c);

	strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
	i2c->adap.owner = THIS_MODULE;
	i2c->adap.algo = &s3c24xx_i2c_algorithm;
	i2c->adap.retries = 2;
	i2c->adap.class = I2C_CLASS_DEPRECATED;
	i2c->tx_setup = 50;

	init_waitqueue_head(&i2c->wait);

	/* find the clock and enable it */
	i2c->dev = &pdev->dev;
	i2c->clk = devm_clk_get(&pdev->dev, "i2c");
	if (IS_ERR(i2c->clk)) {
		dev_err(&pdev->dev, "cannot get clock\n");
		return -ENOENT;
	}

	dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);

	/* map the registers */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	i2c->regs = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(i2c->regs))
		return PTR_ERR(i2c->regs);

	dev_dbg(&pdev->dev, "registers %p (%p)\n",
		i2c->regs, res);

	/* setup info block for the i2c core */
	i2c->adap.algo_data = i2c;
	i2c->adap.dev.parent = &pdev->dev;
	i2c->pctrl = devm_pinctrl_get_select_default(i2c->dev);

	/* inititalise the i2c gpio lines */
	if (i2c->pdata->cfg_gpio)
		i2c->pdata->cfg_gpio(to_platform_device(i2c->dev));
	else if (IS_ERR(i2c->pctrl) && s3c24xx_i2c_parse_dt_gpio(i2c))
		return -EINVAL;

	/* initialise the i2c controller */
	ret = clk_prepare_enable(i2c->clk);
	if (ret) {
		dev_err(&pdev->dev, "I2C clock enable failed\n");
		return ret;
	}

	ret = s3c24xx_i2c_init(i2c);
	clk_disable(i2c->clk);
	if (ret != 0) {
		dev_err(&pdev->dev, "I2C controller init failed\n");
		clk_unprepare(i2c->clk);
		return ret;
	}

	/*
	 * find the IRQ for this unit (note, this relies on the init call to
	 * ensure no current IRQs pending
	 */
	if (!(i2c->quirks & QUIRK_POLL)) {
		i2c->irq = ret = platform_get_irq(pdev, 0);
		if (ret < 0) {
			dev_err(&pdev->dev, "cannot find IRQ\n");
			clk_unprepare(i2c->clk);
			return ret;
		}

		ret = devm_request_irq(&pdev->dev, i2c->irq, s3c24xx_i2c_irq,
				       0, dev_name(&pdev->dev), i2c);
		if (ret != 0) {
			dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
			clk_unprepare(i2c->clk);
			return ret;
		}
	}

	ret = s3c24xx_i2c_register_cpufreq(i2c);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register cpufreq notifier\n");
		clk_unprepare(i2c->clk);
		return ret;
	}

	/*
	 * Note, previous versions of the driver used i2c_add_adapter()
	 * to add the bus at any number. We now pass the bus number via
	 * the platform data, so if unset it will now default to always
	 * being bus 0.
	 */
	i2c->adap.nr = i2c->pdata->bus_num;
	i2c->adap.dev.of_node = pdev->dev.of_node;

	platform_set_drvdata(pdev, i2c);

	pm_runtime_enable(&pdev->dev);

	ret = i2c_add_numbered_adapter(&i2c->adap);
	if (ret < 0) {
		pm_runtime_disable(&pdev->dev);
		s3c24xx_i2c_deregister_cpufreq(i2c);
		clk_unprepare(i2c->clk);
		return ret;
	}

	dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
	return 0;
}