drivers/clk/mmp/pwr-island.c

Source file repositories/reference/linux-study-clean/drivers/clk/mmp/pwr-island.c

File Facts

System
Linux kernel
Corpus path
drivers/clk/mmp/pwr-island.c
Extension
.c
Size
2588 bytes
Lines
116
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 mmp_pm_domain {
	struct generic_pm_domain genpd;
	void __iomem *reg;
	spinlock_t *lock;
	u32 power_on;
	u32 reset;
	u32 clock_enable;
	unsigned int flags;
};

static int mmp_pm_domain_power_on(struct generic_pm_domain *genpd)
{
	struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
	unsigned long flags = 0;
	u32 val;

	if (pm_domain->lock)
		spin_lock_irqsave(pm_domain->lock, flags);

	val = readl(pm_domain->reg);

	/* Turn on the power island */
	val |= pm_domain->power_on;
	writel(val, pm_domain->reg);

	/* Disable isolation */
	val |= 0x100;
	writel(val, pm_domain->reg);

	/* Some blocks need to be reset after a power up */
	if (pm_domain->reset || pm_domain->clock_enable) {
		u32 after_power_on = val;

		val &= ~pm_domain->reset;
		writel(val, pm_domain->reg);

		val |= pm_domain->clock_enable;
		writel(val, pm_domain->reg);

		val |= pm_domain->reset;
		writel(val, pm_domain->reg);

		writel(after_power_on, pm_domain->reg);
	}

	if (pm_domain->lock)
		spin_unlock_irqrestore(pm_domain->lock, flags);

	return 0;
}

static int mmp_pm_domain_power_off(struct generic_pm_domain *genpd)
{
	struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
	unsigned long flags = 0;
	u32 val;

	if (pm_domain->flags & MMP_PM_DOMAIN_NO_DISABLE)
		return 0;

	if (pm_domain->lock)
		spin_lock_irqsave(pm_domain->lock, flags);

	/* Turn off and isolate the power island. */
	val = readl(pm_domain->reg);
	val &= ~pm_domain->power_on;
	val &= ~0x100;
	writel(val, pm_domain->reg);

	if (pm_domain->lock)
		spin_unlock_irqrestore(pm_domain->lock, flags);

	return 0;
}

struct generic_pm_domain *mmp_pm_domain_register(const char *name,
		void __iomem *reg,
		u32 power_on, u32 reset, u32 clock_enable,
		unsigned int flags, spinlock_t *lock)
{
	struct mmp_pm_domain *pm_domain;

	pm_domain = kzalloc_obj(*pm_domain);
	if (!pm_domain)
		return ERR_PTR(-ENOMEM);

	pm_domain->reg = reg;
	pm_domain->power_on = power_on;
	pm_domain->reset = reset;
	pm_domain->clock_enable = clock_enable;

Annotation

Implementation Notes