drivers/clk/socfpga/clk-periph.c

Source file repositories/reference/linux-study-clean/drivers/clk/socfpga/clk-periph.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/socfpga/clk-periph.c
Extension
.c
Size
2928 bytes
Lines
124
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

if (socfpgaclk->div_reg) {
			val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
			val &= GENMASK(socfpgaclk->width - 1, 0);
			parent_rate /= (val + 1);
		}
		div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);
	}

	return parent_rate / div;
}

static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
{
	u32 clk_src;

	clk_src = readl(clk_mgr_base_addr + CLKMGR_DBCTRL);
	return clk_src & 0x1;
}

static const struct clk_ops periclk_ops = {
	.recalc_rate = clk_periclk_recalc_rate,
	.get_parent = clk_periclk_get_parent,
};

static void __init __socfpga_periph_init(struct device_node *node,
					 const struct clk_ops *ops)
{
	u32 reg;
	struct clk_hw *hw_clk;
	struct socfpga_periph_clk *periph_clk;
	const char *clk_name = node->name;
	const char *parent_name[SOCFPGA_MAX_PARENTS];
	struct clk_init_data init;
	int rc;
	u32 fixed_div;
	u32 div_reg[3];

	of_property_read_u32(node, "reg", &reg);

	periph_clk = kzalloc_obj(*periph_clk);
	if (WARN_ON(!periph_clk))
		return;

	periph_clk->hw.reg = clk_mgr_base_addr + reg;

	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
	if (!rc) {
		periph_clk->div_reg = clk_mgr_base_addr + div_reg[0];
		periph_clk->shift = div_reg[1];
		periph_clk->width = div_reg[2];
	} else {
		periph_clk->div_reg = NULL;
	}

	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
	if (rc)
		periph_clk->fixed_div = 0;
	else
		periph_clk->fixed_div = fixed_div;

	of_property_read_string(node, "clock-output-names", &clk_name);

	init.name = clk_name;
	init.ops = ops;
	init.flags = 0;

	init.num_parents = of_clk_parent_fill(node, parent_name,
					      SOCFPGA_MAX_PARENTS);
	init.parent_names = parent_name;

	periph_clk->hw.hw.init = &init;
	hw_clk = &periph_clk->hw.hw;

	rc = clk_hw_register(NULL, hw_clk);
	if (rc) {
		pr_err("Could not register clock:%s\n", clk_name);
		goto err_clk_hw_register;
	}

	rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw_clk);
	if (rc) {
		pr_err("Could not register clock provider for node:%s\n",
		       clk_name);
		goto err_of_clk_add_hw_provider;
	}

	return;

err_of_clk_add_hw_provider:
	clk_hw_unregister(hw_clk);

Annotation

Implementation Notes