drivers/clk/hisilicon/reset.c

Source file repositories/reference/linux-study-clean/drivers/clk/hisilicon/reset.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/hisilicon/reset.c
Extension
.c
Size
2876 bytes
Lines
119
Domain
Driver Families
Bucket
drivers/clk
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 hisi_reset_controller {
	spinlock_t	lock;
	void __iomem	*membase;
	struct reset_controller_dev	rcdev;
};


#define to_hisi_reset_controller(rcdev)  \
	container_of(rcdev, struct hisi_reset_controller, rcdev)

static int hisi_reset_of_xlate(struct reset_controller_dev *rcdev,
			const struct of_phandle_args *reset_spec)
{
	u32 offset;
	u8 bit;

	offset = (reset_spec->args[0] << HISI_RESET_OFFSET_SHIFT)
		& HISI_RESET_OFFSET_MASK;
	bit = reset_spec->args[1] & HISI_RESET_BIT_MASK;

	return (offset | bit);
}

static int hisi_reset_assert(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev);
	unsigned long flags;
	u32 offset, reg;
	u8 bit;

	offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT;
	bit = id & HISI_RESET_BIT_MASK;

	spin_lock_irqsave(&rstc->lock, flags);

	reg = readl(rstc->membase + offset);
	writel(reg | BIT(bit), rstc->membase + offset);

	spin_unlock_irqrestore(&rstc->lock, flags);

	return 0;
}

static int hisi_reset_deassert(struct reset_controller_dev *rcdev,
				unsigned long id)
{
	struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev);
	unsigned long flags;
	u32 offset, reg;
	u8 bit;

	offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT;
	bit = id & HISI_RESET_BIT_MASK;

	spin_lock_irqsave(&rstc->lock, flags);

	reg = readl(rstc->membase + offset);
	writel(reg & ~BIT(bit), rstc->membase + offset);

	spin_unlock_irqrestore(&rstc->lock, flags);

	return 0;
}

static const struct reset_control_ops hisi_reset_ops = {
	.assert		= hisi_reset_assert,
	.deassert	= hisi_reset_deassert,
};

struct hisi_reset_controller *hisi_reset_init(struct platform_device *pdev)
{
	struct hisi_reset_controller *rstc;

	rstc = devm_kmalloc(&pdev->dev, sizeof(*rstc), GFP_KERNEL);
	if (!rstc)
		return NULL;

	rstc->membase = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(rstc->membase))
		return NULL;

	spin_lock_init(&rstc->lock);
	rstc->rcdev.owner = THIS_MODULE;
	rstc->rcdev.ops = &hisi_reset_ops;
	rstc->rcdev.of_node = pdev->dev.of_node;
	rstc->rcdev.of_reset_n_cells = 2;
	rstc->rcdev.of_xlate = hisi_reset_of_xlate;
	reset_controller_register(&rstc->rcdev);

Annotation

Implementation Notes