drivers/clk/imx/clk-fixup-div.c

Source file repositories/reference/linux-study-clean/drivers/clk/imx/clk-fixup-div.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/imx/clk-fixup-div.c
Extension
.c
Size
3076 bytes
Lines
128
Domain
Driver Families
Bucket
drivers/clk
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 clk_fixup_div {
	struct clk_divider divider;
	const struct clk_ops *ops;
	void (*fixup)(u32 *val);
};

static inline struct clk_fixup_div *to_clk_fixup_div(struct clk_hw *hw)
{
	struct clk_divider *divider = to_clk_divider(hw);

	return container_of(divider, struct clk_fixup_div, divider);
}

static unsigned long clk_fixup_div_recalc_rate(struct clk_hw *hw,
					 unsigned long parent_rate)
{
	struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);

	return fixup_div->ops->recalc_rate(&fixup_div->divider.hw, parent_rate);
}

static int clk_fixup_div_determine_rate(struct clk_hw *hw,
					struct clk_rate_request *req)
{
	struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);

	return fixup_div->ops->determine_rate(&fixup_div->divider.hw, req);
}

static int clk_fixup_div_set_rate(struct clk_hw *hw, unsigned long rate,
			    unsigned long parent_rate)
{
	struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
	struct clk_divider *div = to_clk_divider(hw);
	unsigned int divider, value;
	unsigned long flags;
	u32 val;

	divider = parent_rate / rate;

	/* Zero based divider */
	value = divider - 1;

	if (value > div_mask(div))
		value = div_mask(div);

	spin_lock_irqsave(div->lock, flags);

	val = readl(div->reg);
	val &= ~(div_mask(div) << div->shift);
	val |= value << div->shift;
	fixup_div->fixup(&val);
	writel(val, div->reg);

	spin_unlock_irqrestore(div->lock, flags);

	return 0;
}

static const struct clk_ops clk_fixup_div_ops = {
	.recalc_rate = clk_fixup_div_recalc_rate,
	.determine_rate = clk_fixup_div_determine_rate,
	.set_rate = clk_fixup_div_set_rate,
};

struct clk_hw *imx_clk_hw_fixup_divider(const char *name, const char *parent,
				  void __iomem *reg, u8 shift, u8 width,
				  void (*fixup)(u32 *val))
{
	struct clk_fixup_div *fixup_div;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	if (!fixup)
		return ERR_PTR(-EINVAL);

	fixup_div = kzalloc_obj(*fixup_div);
	if (!fixup_div)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &clk_fixup_div_ops;
	init.flags = CLK_SET_RATE_PARENT;
	init.parent_names = parent ? &parent : NULL;
	init.num_parents = parent ? 1 : 0;

	fixup_div->divider.reg = reg;
	fixup_div->divider.shift = shift;
	fixup_div->divider.width = width;

Annotation

Implementation Notes