drivers/clk/meson/clk-dualdiv.c

Source file repositories/reference/linux-study-clean/drivers/clk/meson/clk-dualdiv.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/meson/clk-dualdiv.c
Extension
.c
Size
4374 bytes
Lines
147
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

if (now == rate) {
			return &table[i];
		} else if (abs(now - rate) < abs(best - rate)) {
			best = now;
			best_i = i;
		}
	}

	return (struct meson_clk_dualdiv_param *)&table[best_i];
}

static int meson_clk_dualdiv_determine_rate(struct clk_hw *hw,
					    struct clk_rate_request *req)
{
	struct clk_regmap *clk = to_clk_regmap(hw);
	struct meson_clk_dualdiv_data *dualdiv = meson_clk_dualdiv_data(clk);
	const struct meson_clk_dualdiv_param *setting;

	setting = __dualdiv_get_setting(req->rate, req->best_parent_rate,
					dualdiv);
	if (setting)
		req->rate = __dualdiv_param_to_rate(req->best_parent_rate,
						    setting);
	else
		req->rate = meson_clk_dualdiv_recalc_rate(hw,
							  req->best_parent_rate);

	return 0;
}

static int meson_clk_dualdiv_set_rate(struct clk_hw *hw, unsigned long rate,
				      unsigned long parent_rate)
{
	struct clk_regmap *clk = to_clk_regmap(hw);
	struct meson_clk_dualdiv_data *dualdiv = meson_clk_dualdiv_data(clk);
	const struct meson_clk_dualdiv_param *setting =
		__dualdiv_get_setting(rate, parent_rate, dualdiv);

	if (!setting)
		return -EINVAL;

	meson_parm_write(clk->map, &dualdiv->dual, setting->dual);
	meson_parm_write(clk->map, &dualdiv->n1, setting->n1 - 1);
	meson_parm_write(clk->map, &dualdiv->m1, setting->m1 - 1);
	meson_parm_write(clk->map, &dualdiv->n2, setting->n2 - 1);
	meson_parm_write(clk->map, &dualdiv->m2, setting->m2 - 1);

	return 0;
}

const struct clk_ops meson_clk_dualdiv_ops = {
	.init		= clk_regmap_init,
	.recalc_rate	= meson_clk_dualdiv_recalc_rate,
	.determine_rate	= meson_clk_dualdiv_determine_rate,
	.set_rate	= meson_clk_dualdiv_set_rate,
};
EXPORT_SYMBOL_NS_GPL(meson_clk_dualdiv_ops, "CLK_MESON");

const struct clk_ops meson_clk_dualdiv_ro_ops = {
	.init		= clk_regmap_init,
	.recalc_rate	= meson_clk_dualdiv_recalc_rate,
};
EXPORT_SYMBOL_NS_GPL(meson_clk_dualdiv_ro_ops, "CLK_MESON");

MODULE_DESCRIPTION("Amlogic dual divider driver");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("CLK_MESON");

Annotation

Implementation Notes