arch/sh/kernel/cpu/sh4a/clock-sh7780.c

Source file repositories/reference/linux-study-clean/arch/sh/kernel/cpu/sh4a/clock-sh7780.c

File Facts

System
Linux kernel
Corpus path
arch/sh/kernel/cpu/sh4a/clock-sh7780.c
Extension
.c
Size
2712 bytes
Lines
123
Domain
Architecture Layer
Bucket
arch/sh
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sh/kernel/cpu/sh4a/clock-sh7780.c
 *
 * SH7780 support for the clock framework
 *
 *  Copyright (C) 2005  Paul Mundt
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/clkdev.h>
#include <asm/clock.h>
#include <asm/freq.h>
#include <asm/io.h>

static int ifc_divisors[] = { 2, 4 };
static int bfc_divisors[] = { 1, 1, 1, 8, 12, 16, 24, 1 };
static int pfc_divisors[] = { 1, 24, 24, 1 };
static int cfc_divisors[] = { 1, 1, 4, 1, 6, 1, 1, 1 };

static void master_clk_init(struct clk *clk)
{
	clk->rate *= pfc_divisors[__raw_readl(FRQCR) & 0x0003];
}

static struct sh_clk_ops sh7780_master_clk_ops = {
	.init		= master_clk_init,
};

static unsigned long module_clk_recalc(struct clk *clk)
{
	int idx = (__raw_readl(FRQCR) & 0x0003);
	return clk->parent->rate / pfc_divisors[idx];
}

static struct sh_clk_ops sh7780_module_clk_ops = {
	.recalc		= module_clk_recalc,
};

static unsigned long bus_clk_recalc(struct clk *clk)
{
	int idx = ((__raw_readl(FRQCR) >> 16) & 0x0007);
	return clk->parent->rate / bfc_divisors[idx];
}

static struct sh_clk_ops sh7780_bus_clk_ops = {
	.recalc		= bus_clk_recalc,
};

static unsigned long cpu_clk_recalc(struct clk *clk)
{
	int idx = ((__raw_readl(FRQCR) >> 24) & 0x0001);
	return clk->parent->rate / ifc_divisors[idx];
}

static struct sh_clk_ops sh7780_cpu_clk_ops = {
	.recalc		= cpu_clk_recalc,
};

static struct sh_clk_ops *sh7780_clk_ops[] = {
	&sh7780_master_clk_ops,
	&sh7780_module_clk_ops,
	&sh7780_bus_clk_ops,
	&sh7780_cpu_clk_ops,
};

void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
{
	if (idx < ARRAY_SIZE(sh7780_clk_ops))
		*ops = sh7780_clk_ops[idx];
}

static unsigned long shyway_clk_recalc(struct clk *clk)
{
	int idx = ((__raw_readl(FRQCR) >> 20) & 0x0007);
	return clk->parent->rate / cfc_divisors[idx];
}

static struct sh_clk_ops sh7780_shyway_clk_ops = {
	.recalc		= shyway_clk_recalc,
};

static struct clk sh7780_shyway_clk = {
	.flags		= CLK_ENABLE_ON_INIT,
	.ops		= &sh7780_shyway_clk_ops,
};

/*
 * Additional SH7780-specific on-chip clocks that aren't already part of the

Annotation

Implementation Notes