static int sh_cmt_setup()

in sh_cmt.c [988:1079]

• 68 lines of code
• 13 McCabe index (conditional complexity)

static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
{
	unsigned int mask;
	unsigned int i;
	int ret;

	cmt->pdev = pdev;
	raw_spin_lock_init(&cmt->lock);

	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
		cmt->info = of_device_get_match_data(&pdev->dev);
		cmt->hw_channels = cmt->info->channels_mask;
	} else if (pdev->dev.platform_data) {
		struct sh_timer_config *cfg = pdev->dev.platform_data;
		const struct platform_device_id *id = pdev->id_entry;

		cmt->info = (const struct sh_cmt_info *)id->driver_data;
		cmt->hw_channels = cfg->channels_mask;
	} else {
		dev_err(&cmt->pdev->dev, "missing platform data\n");
		return -ENXIO;
	}

	/* Get hold of clock. */
	cmt->clk = clk_get(&cmt->pdev->dev, "fck");
	if (IS_ERR(cmt->clk)) {
		dev_err(&cmt->pdev->dev, "cannot get clock\n");
		return PTR_ERR(cmt->clk);
	}

	ret = clk_prepare(cmt->clk);
	if (ret < 0)
		goto err_clk_put;

	/* Determine clock rate. */
	ret = clk_enable(cmt->clk);
	if (ret < 0)
		goto err_clk_unprepare;

	if (cmt->info->width == 16)
		cmt->rate = clk_get_rate(cmt->clk) / 512;
	else
		cmt->rate = clk_get_rate(cmt->clk) / 8;

	/* Map the memory resource(s). */
	ret = sh_cmt_map_memory(cmt);
	if (ret < 0)
		goto err_clk_disable;

	/* Allocate and setup the channels. */
	cmt->num_channels = hweight8(cmt->hw_channels);
	cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels),
				GFP_KERNEL);
	if (cmt->channels == NULL) {
		ret = -ENOMEM;
		goto err_unmap;
	}

	/*
	 * Use the first channel as a clock event device and the second channel
	 * as a clock source. If only one channel is available use it for both.
	 */
	for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
		unsigned int hwidx = ffs(mask) - 1;
		bool clocksource = i == 1 || cmt->num_channels == 1;
		bool clockevent = i == 0;

		ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx,
					   clockevent, clocksource, cmt);
		if (ret < 0)
			goto err_unmap;

		mask &= ~(1 << hwidx);
	}

	clk_disable(cmt->clk);

	platform_set_drvdata(pdev, cmt);

	return 0;

err_unmap:
	kfree(cmt->channels);
	iounmap(cmt->mapbase);
err_clk_disable:
	clk_disable(cmt->clk);
err_clk_unprepare:
	clk_unprepare(cmt->clk);
err_clk_put:
	clk_put(cmt->clk);
	return ret;
}