drivers/pmdomain/renesas/rcar-sysc.c

Source file repositories/reference/linux-study-clean/drivers/pmdomain/renesas/rcar-sysc.c

File Facts

System
Linux kernel
Corpus path
drivers/pmdomain/renesas/rcar-sysc.c
Extension
.c
Size
12940 bytes
Lines
492
Domain
Driver Families
Bucket
drivers/pmdomain
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

struct rcar_sysc_pd {
	struct generic_pm_domain genpd;
	u16 chan_offs;
	u8 chan_bit;
	u8 isr_bit;
	unsigned int flags;
	char name[];
};

static void __iomem *rcar_sysc_base;
static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
static u32 rcar_sysc_extmask_offs, rcar_sysc_extmask_val;

static int rcar_sysc_pwr_on_off(const struct rcar_sysc_pd *pd, bool on)
{
	unsigned int sr_bit, reg_offs;
	u32 val;
	int ret;

	if (on) {
		sr_bit = SYSCSR_PONENB;
		reg_offs = PWRONCR_OFFS;
	} else {
		sr_bit = SYSCSR_POFFENB;
		reg_offs = PWROFFCR_OFFS;
	}

	/* Wait until SYSC is ready to accept a power request */
	ret = readl_poll_timeout_atomic(rcar_sysc_base + SYSCSR, val,
					val & BIT(sr_bit), SYSCSR_DELAY_US,
					SYSCSR_TIMEOUT);
	if (ret)
		return -EAGAIN;

	/* Power-off delay quirk */
	if (!on && (pd->flags & PD_OFF_DELAY))
		udelay(1);

	/* Submit power shutoff or power resume request */
	iowrite32(BIT(pd->chan_bit), rcar_sysc_base + pd->chan_offs + reg_offs);

	return 0;
}

static int rcar_sysc_power(const struct rcar_sysc_pd *pd, bool on)
{
	unsigned int isr_mask = BIT(pd->isr_bit);
	unsigned int chan_mask = BIT(pd->chan_bit);
	unsigned int status, k;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&rcar_sysc_lock, flags);

	/*
	 * Mask external power requests for CPU or 3DG domains
	 */
	if (rcar_sysc_extmask_val) {
		iowrite32(rcar_sysc_extmask_val,
			  rcar_sysc_base + rcar_sysc_extmask_offs);
	}

	/*
	 * The interrupt source needs to be enabled, but masked, to prevent the
	 * CPU from receiving it.
	 */
	iowrite32(ioread32(rcar_sysc_base + SYSCIMR) | isr_mask,
		  rcar_sysc_base + SYSCIMR);
	iowrite32(ioread32(rcar_sysc_base + SYSCIER) | isr_mask,
		  rcar_sysc_base + SYSCIER);

	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);

	/* Submit power shutoff or resume request until it was accepted */
	for (k = 0; k < PWRER_RETRIES; k++) {
		ret = rcar_sysc_pwr_on_off(pd, on);
		if (ret)
			goto out;

		status = ioread32(rcar_sysc_base + pd->chan_offs + PWRER_OFFS);
		if (!(status & chan_mask))
			break;

		udelay(PWRER_DELAY_US);
	}

	if (k == PWRER_RETRIES) {
		ret = -EIO;
		goto out;
	}

Annotation

Implementation Notes