static int mxc_w1_probe()

in masters/mxc_w1.c [91:149]

• 45 lines of code
• 8 McCabe index (conditional complexity)

static int mxc_w1_probe(struct platform_device *pdev)
{
	struct mxc_w1_device *mdev;
	unsigned long clkrate;
	unsigned int clkdiv;
	int err;

	mdev = devm_kzalloc(&pdev->dev, sizeof(struct mxc_w1_device),
			    GFP_KERNEL);
	if (!mdev)
		return -ENOMEM;

	mdev->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(mdev->clk))
		return PTR_ERR(mdev->clk);

	err = clk_prepare_enable(mdev->clk);
	if (err)
		return err;

	clkrate = clk_get_rate(mdev->clk);
	if (clkrate < 10000000)
		dev_warn(&pdev->dev,
			 "Low clock frequency causes improper function\n");

	clkdiv = DIV_ROUND_CLOSEST(clkrate, 1000000);
	clkrate /= clkdiv;
	if ((clkrate < 980000) || (clkrate > 1020000))
		dev_warn(&pdev->dev,
			 "Incorrect time base frequency %lu Hz\n", clkrate);

	mdev->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(mdev->regs)) {
		err = PTR_ERR(mdev->regs);
		goto out_disable_clk;
	}

	/* Software reset 1-Wire module */
	writeb(MXC_W1_RESET_RST, mdev->regs + MXC_W1_RESET);
	writeb(0, mdev->regs + MXC_W1_RESET);

	writeb(clkdiv - 1, mdev->regs + MXC_W1_TIME_DIVIDER);

	mdev->bus_master.data = mdev;
	mdev->bus_master.reset_bus = mxc_w1_ds2_reset_bus;
	mdev->bus_master.touch_bit = mxc_w1_ds2_touch_bit;

	platform_set_drvdata(pdev, mdev);

	err = w1_add_master_device(&mdev->bus_master);
	if (err)
		goto out_disable_clk;

	return 0;

out_disable_clk:
	clk_disable_unprepare(mdev->clk);
	return err;
}