drivers/pmdomain/sunxi/sun20i-ppu.c

Source file repositories/reference/linux-study-clean/drivers/pmdomain/sunxi/sun20i-ppu.c

File Facts

System
Linux kernel
Corpus path
drivers/pmdomain/sunxi/sun20i-ppu.c
Extension
.c
Size
5747 bytes
Lines
240
Domain
Driver Families
Bucket
drivers/pmdomain
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 sun20i_ppu_desc {
	const char *const		*names;
	unsigned int			num_domains;
};

struct sun20i_ppu_pd {
	struct generic_pm_domain	genpd;
	void __iomem			*base;
};

#define to_sun20i_ppu_pd(_genpd) \
	container_of(_genpd, struct sun20i_ppu_pd, genpd)

static bool sun20i_ppu_pd_is_on(const struct sun20i_ppu_pd *pd)
{
	u32 status = readl(pd->base + PD_STATUS_REG);

	return FIELD_GET(PD_STATUS_STATE, status) == PD_STATE_ON;
}

static int sun20i_ppu_pd_set_power(const struct sun20i_ppu_pd *pd, bool power_on)
{
	u32 state, status;
	int ret;

	if (sun20i_ppu_pd_is_on(pd) == power_on)
		return 0;

	/* Wait for the power controller to be idle. */
	ret = readl_poll_timeout(pd->base + PD_STATUS_REG, status,
				 !(status & PD_STATUS_BUSY), 100, 1000);
	if (ret)
		return ret;

	state = power_on ? PD_STATE_ON : PD_STATE_OFF;
	writel(state, pd->base + PD_COMMAND_REG);

	/* Wait for the state transition to complete. */
	ret = readl_poll_timeout(pd->base + PD_STATUS_REG, status,
				 FIELD_GET(PD_STATUS_STATE, status) == state &&
				 (status & PD_STATUS_COMPLETE), 100, 1000);
	if (ret)
		return ret;

	/* Clear the completion flag. */
	writel(status, pd->base + PD_STATUS_REG);

	return 0;
}

static int sun20i_ppu_pd_power_on(struct generic_pm_domain *genpd)
{
	const struct sun20i_ppu_pd *pd = to_sun20i_ppu_pd(genpd);

	return sun20i_ppu_pd_set_power(pd, true);
}

static int sun20i_ppu_pd_power_off(struct generic_pm_domain *genpd)
{
	const struct sun20i_ppu_pd *pd = to_sun20i_ppu_pd(genpd);

	return sun20i_ppu_pd_set_power(pd, false);
}

static int sun20i_ppu_probe(struct platform_device *pdev)
{
	const struct sun20i_ppu_desc *desc;
	struct device *dev = &pdev->dev;
	struct genpd_onecell_data *ppu;
	struct sun20i_ppu_pd *pds;
	struct reset_control *rst;
	void __iomem *base;
	struct clk *clk;
	int ret;

	desc = of_device_get_match_data(dev);
	if (!desc)
		return -EINVAL;

	pds = devm_kcalloc(dev, desc->num_domains, sizeof(*pds), GFP_KERNEL);
	if (!pds)
		return -ENOMEM;

	ppu = devm_kzalloc(dev, sizeof(*ppu), GFP_KERNEL);
	if (!ppu)
		return -ENOMEM;

	ppu->domains = devm_kcalloc(dev, desc->num_domains,
				    sizeof(*ppu->domains), GFP_KERNEL);
	if (!ppu->domains)

Annotation

Implementation Notes