drivers/rtc/rtc-sun4v.c

Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-sun4v.c

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-sun4v.c
Extension
.c
Size
1976 bytes
Lines
99
Domain
Driver Families
Bucket
drivers/rtc
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

if (--retries > 0) {
			udelay(100);
			goto retry;
		}
		pr_warn("tod_get() timed out.\n");
		return 0;
	}
	pr_warn("tod_get() not supported.\n");
	return 0;
}

static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
{
	rtc_time64_to_tm(hypervisor_get_time(), tm);
	return 0;
}

static int hypervisor_set_time(unsigned long secs)
{
	unsigned long ret;
	int retries = 10000;

retry:
	ret = sun4v_tod_set(secs);
	if (ret == HV_EOK)
		return 0;
	if (ret == HV_EWOULDBLOCK) {
		if (--retries > 0) {
			udelay(100);
			goto retry;
		}
		pr_warn("tod_set() timed out.\n");
		return -EAGAIN;
	}
	pr_warn("tod_set() not supported.\n");
	return -EOPNOTSUPP;
}

static int sun4v_set_time(struct device *dev, struct rtc_time *tm)
{
	return hypervisor_set_time(rtc_tm_to_time64(tm));
}

static const struct rtc_class_ops sun4v_rtc_ops = {
	.read_time	= sun4v_read_time,
	.set_time	= sun4v_set_time,
};

static int __init sun4v_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;

	rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	rtc->ops = &sun4v_rtc_ops;
	rtc->range_max = U64_MAX;
	platform_set_drvdata(pdev, rtc);

	return devm_rtc_register_device(rtc);
}

static struct platform_driver sun4v_rtc_driver = {
	.driver		= {
		.name	= "rtc-sun4v",
	},
};

builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);

Annotation

Implementation Notes