drivers/clk/renesas/clk-r8a73a4.c

Source file repositories/reference/linux-study-clean/drivers/clk/renesas/clk-r8a73a4.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/renesas/clk-r8a73a4.c
Extension
.c
Size
5250 bytes
Lines
236
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 r8a73a4_cpg {
	struct clk_onecell_data data;
	spinlock_t lock;
};

#define CPG_CKSCR	0xc0
#define CPG_FRQCRA	0x00
#define CPG_FRQCRB	0x04
#define CPG_FRQCRC	0xe0
#define CPG_PLL0CR	0xd8
#define CPG_PLL1CR	0x28
#define CPG_PLL2CR	0x2c
#define CPG_PLL2HCR	0xe4
#define CPG_PLL2SCR	0xf4

struct div4_clk {
	const char *name;
	unsigned int reg;
	unsigned int shift;
};

static struct div4_clk div4_clks[] = {
	{ "i",	CPG_FRQCRA, 20 },
	{ "m3", CPG_FRQCRA, 12 },
	{ "b",	CPG_FRQCRA,  8 },
	{ "m1", CPG_FRQCRA,  4 },
	{ "m2", CPG_FRQCRA,  0 },
	{ "zx", CPG_FRQCRB, 12 },
	{ "zs", CPG_FRQCRB,  8 },
	{ "hp", CPG_FRQCRB,  4 },
	{ NULL, 0, 0 },
};

static const struct clk_div_table div4_div_table[] = {
	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
	{ 12, 10 }, { 0, 0 }
};

static struct clk * __init
r8a73a4_cpg_register_clock(struct device_node *np, struct r8a73a4_cpg *cpg,
			   void __iomem *base, const char *name)
{
	const struct clk_div_table *table = NULL;
	const char *parent_name;
	unsigned int shift, reg;
	unsigned int mult = 1;
	unsigned int div = 1;

	if (!strcmp(name, "main")) {
		u32 ckscr = readl(base + CPG_CKSCR);

		switch ((ckscr >> 28) & 3) {
		case 0:	/* extal1 */
			parent_name = of_clk_get_parent_name(np, 0);
			break;
		case 1:	/* extal1 / 2 */
			parent_name = of_clk_get_parent_name(np, 0);
			div = 2;
			break;
		case 2: /* extal2 */
			parent_name = of_clk_get_parent_name(np, 1);
			break;
		case 3: /* extal2 / 2 */
			parent_name = of_clk_get_parent_name(np, 1);
			div = 2;
			break;
		}
	} else if (!strcmp(name, "pll0")) {
		/* PLL0/1 are configurable multiplier clocks. Register them as
		 * fixed factor clocks for now as there's no generic multiplier
		 * clock implementation and we currently have no need to change
		 * the multiplier value.
		 */
		u32 value = readl(base + CPG_PLL0CR);

		parent_name = "main";
		mult = ((value >> 24) & 0x7f) + 1;
		if (value & BIT(20))
			div = 2;
	} else if (!strcmp(name, "pll1")) {
		u32 value = readl(base + CPG_PLL1CR);

		parent_name = "main";
		/* XXX: enable bit? */
		mult = ((value >> 24) & 0x7f) + 1;
		if (value & BIT(7))
			div = 2;
	} else if (!strncmp(name, "pll2", 4)) {
		u32 value, cr;

Annotation

Implementation Notes