drivers/clk/sunxi-ng/ccu_frac.c

Source file repositories/reference/linux-study-clean/drivers/clk/sunxi-ng/ccu_frac.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/sunxi-ng/ccu_frac.c
Extension
.c
Size
3038 bytes
Lines
116
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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Maxime Ripard
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/spinlock.h>

#include "ccu_frac.h"

bool ccu_frac_helper_is_enabled(struct ccu_common *common,
				struct ccu_frac_internal *cf)
{
	if (!(common->features & CCU_FEATURE_FRACTIONAL))
		return false;

	return !(readl(common->base + common->reg) & cf->enable);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_is_enabled, "SUNXI_CCU");

void ccu_frac_helper_enable(struct ccu_common *common,
			    struct ccu_frac_internal *cf)
{
	unsigned long flags;
	u32 reg;

	if (!(common->features & CCU_FEATURE_FRACTIONAL))
		return;

	spin_lock_irqsave(common->lock, flags);
	reg = readl(common->base + common->reg);
	writel(reg & ~cf->enable, common->base + common->reg);
	spin_unlock_irqrestore(common->lock, flags);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_enable, "SUNXI_CCU");

void ccu_frac_helper_disable(struct ccu_common *common,
			     struct ccu_frac_internal *cf)
{
	unsigned long flags;
	u32 reg;

	if (!(common->features & CCU_FEATURE_FRACTIONAL))
		return;

	spin_lock_irqsave(common->lock, flags);
	reg = readl(common->base + common->reg);
	writel(reg | cf->enable, common->base + common->reg);
	spin_unlock_irqrestore(common->lock, flags);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_disable, "SUNXI_CCU");

bool ccu_frac_helper_has_rate(struct ccu_common *common,
			      struct ccu_frac_internal *cf,
			      unsigned long rate)
{
	if (!(common->features & CCU_FEATURE_FRACTIONAL))
		return false;

	return (cf->rates[0] == rate) || (cf->rates[1] == rate);
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_has_rate, "SUNXI_CCU");

unsigned long ccu_frac_helper_read_rate(struct ccu_common *common,
					struct ccu_frac_internal *cf)
{
	u32 reg;

	pr_debug("%s: Read fractional\n", clk_hw_get_name(&common->hw));

	if (!(common->features & CCU_FEATURE_FRACTIONAL))
		return 0;

	pr_debug("%s: clock is fractional (rates %lu and %lu)\n",
		 clk_hw_get_name(&common->hw), cf->rates[0], cf->rates[1]);

	reg = readl(common->base + common->reg);

	pr_debug("%s: clock reg is 0x%x (select is 0x%x)\n",
		 clk_hw_get_name(&common->hw), reg, cf->select);

	return (reg & cf->select) ? cf->rates[1] : cf->rates[0];
}
EXPORT_SYMBOL_NS_GPL(ccu_frac_helper_read_rate, "SUNXI_CCU");

int ccu_frac_helper_set_rate(struct ccu_common *common,
			     struct ccu_frac_internal *cf,
			     unsigned long rate, u32 lock)

Annotation

Implementation Notes