drivers/clk/rockchip/softrst.c

Source file repositories/reference/linux-study-clean/drivers/clk/rockchip/softrst.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/rockchip/softrst.c
Extension
.c
Size
3038 bytes
Lines
127
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 rockchip_softrst {
	struct reset_controller_dev	rcdev;
	const int			*lut;
	void __iomem			*reg_base;
	int				num_regs;
	int				num_per_reg;
	u8				flags;
	spinlock_t			lock;
};

static int rockchip_softrst_assert(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	struct rockchip_softrst *softrst = container_of(rcdev,
						     struct rockchip_softrst,
						     rcdev);
	int bank, offset;

	if (softrst->lut)
		id = softrst->lut[id];

	bank = id / softrst->num_per_reg;
	offset = id % softrst->num_per_reg;

	if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
		writel(BIT(offset) | (BIT(offset) << 16),
		       softrst->reg_base + (bank * 4));
	} else {
		unsigned long flags;
		u32 reg;

		spin_lock_irqsave(&softrst->lock, flags);

		reg = readl(softrst->reg_base + (bank * 4));
		writel(reg | BIT(offset), softrst->reg_base + (bank * 4));

		spin_unlock_irqrestore(&softrst->lock, flags);
	}

	return 0;
}

static int rockchip_softrst_deassert(struct reset_controller_dev *rcdev,
				unsigned long id)
{
	struct rockchip_softrst *softrst = container_of(rcdev,
						     struct rockchip_softrst,
						     rcdev);
	int bank, offset;

	if (softrst->lut)
		id = softrst->lut[id];

	bank = id / softrst->num_per_reg;
	offset = id % softrst->num_per_reg;

	if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
		writel((BIT(offset) << 16), softrst->reg_base + (bank * 4));
	} else {
		unsigned long flags;
		u32 reg;

		spin_lock_irqsave(&softrst->lock, flags);

		reg = readl(softrst->reg_base + (bank * 4));
		writel(reg & ~BIT(offset), softrst->reg_base + (bank * 4));

		spin_unlock_irqrestore(&softrst->lock, flags);
	}

	return 0;
}

static const struct reset_control_ops rockchip_softrst_ops = {
	.assert		= rockchip_softrst_assert,
	.deassert	= rockchip_softrst_deassert,
};

void rockchip_register_softrst_lut(struct device_node *np,
				   const int *lookup_table,
				   unsigned int num_regs,
				   void __iomem *base, u8 flags)
{
	struct rockchip_softrst *softrst;
	int ret;

	softrst = kzalloc_obj(*softrst);
	if (!softrst)
		return;

Annotation

Implementation Notes