drivers/usb/dwc3/dwc3-of-simple.c

Source file repositories/reference/linux-study-clean/drivers/usb/dwc3/dwc3-of-simple.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/dwc3/dwc3-of-simple.c
Extension
.c
Size
5076 bytes
Lines
197
Domain
Driver Families
Bucket
drivers/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct dwc3_of_simple {
	struct device		*dev;
	struct clk_bulk_data	*clks;
	int			num_clocks;
	struct reset_control	*resets;
	bool			need_reset;
};

static int dwc3_of_simple_probe(struct platform_device *pdev)
{
	struct dwc3_of_simple	*simple;
	struct device		*dev = &pdev->dev;
	struct device_node	*np = dev->of_node;

	int			ret;

	simple = devm_kzalloc(dev, sizeof(*simple), GFP_KERNEL);
	if (!simple)
		return -ENOMEM;

	platform_set_drvdata(pdev, simple);
	simple->dev = dev;

	/*
	 * Some controllers need to toggle the usb3-otg reset before trying to
	 * initialize the PHY, otherwise the PHY times out.
	 */
	if (of_device_is_compatible(np, "rockchip,rk3399-dwc3"))
		simple->need_reset = true;

	simple->resets = of_reset_control_array_get_optional_exclusive(np);
	if (IS_ERR(simple->resets)) {
		ret = PTR_ERR(simple->resets);
		dev_err(dev, "failed to get device resets, err=%d\n", ret);
		return ret;
	}

	ret = reset_control_deassert(simple->resets);
	if (ret)
		goto err_resetc_put;

	ret = clk_bulk_get_all(simple->dev, &simple->clks);
	if (ret < 0)
		goto err_resetc_assert;

	simple->num_clocks = ret;
	ret = clk_bulk_prepare_enable(simple->num_clocks, simple->clks);
	if (ret)
		goto err_clk_put_all;

	ret = of_platform_populate(np, NULL, NULL, dev);
	if (ret)
		goto err_clk_disable;

	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	pm_runtime_get_sync(dev);

	return 0;

err_clk_disable:
	clk_bulk_disable_unprepare(simple->num_clocks, simple->clks);
err_clk_put_all:
	clk_bulk_put_all(simple->num_clocks, simple->clks);

err_resetc_assert:
	reset_control_assert(simple->resets);

err_resetc_put:
	reset_control_put(simple->resets);
	return ret;
}

static void __dwc3_of_simple_teardown(struct dwc3_of_simple *simple)
{
	of_platform_depopulate(simple->dev);

	clk_bulk_disable_unprepare(simple->num_clocks, simple->clks);
	clk_bulk_put_all(simple->num_clocks, simple->clks);
	simple->num_clocks = 0;

	reset_control_assert(simple->resets);

	reset_control_put(simple->resets);

	pm_runtime_disable(simple->dev);
	pm_runtime_put_noidle(simple->dev);
	pm_runtime_set_suspended(simple->dev);
}

Annotation

Implementation Notes