[deliverable/linux.git] / drivers / rtc / rtc-sun4v.c

/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
 *
 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>

#include <asm/hypervisor.h>

static unsigned long hypervisor_get_time(void)
{
	unsigned long ret, time;
	int retries = 10000;

retry:
	ret = sun4v_tod_get(&time);
	if (ret == HV_EOK)
		return time;
	if (ret == HV_EWOULDBLOCK) {
		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_time_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)
{
	unsigned long secs;
	int err;

	err = rtc_tm_to_time(tm, &secs);
	if (err)
		return err;

	return hypervisor_set_time(secs);
}

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_device_register(&pdev->dev, "sun4v",
				&sun4v_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	platform_set_drvdata(pdev, rtc);
	return 0;
}

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

module_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);

MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
MODULE_DESCRIPTION("SUN4V RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
	2	*
	3	* Copyright (C) 2008 David S. Miller <davem@davemloft.net>
	4	*/
	5
	6	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	7
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/delay.h>
	11	#include <linux/init.h>
	12	#include <linux/rtc.h>
	13	#include <linux/platform_device.h>
	14
	15	#include <asm/hypervisor.h>
	16
	17	static unsigned long hypervisor_get_time(void)
	18	{
	19	unsigned long ret, time;
	20	int retries = 10000;
	21
	22	retry:
	23	ret = sun4v_tod_get(&time);
	24	if (ret == HV_EOK)
	25	return time;
	26	if (ret == HV_EWOULDBLOCK) {
	27	if (--retries > 0) {
	28	udelay(100);
	29	goto retry;
	30	}
	31	pr_warn("tod_get() timed out.\n");
	32	return 0;
	33	}
	34	pr_warn("tod_get() not supported.\n");
	35	return 0;
	36	}
	37
	38	static int sun4v_read_time(struct device dev, struct rtc_time tm)
	39	{
	40	rtc_time_to_tm(hypervisor_get_time(), tm);
	41	return 0;
	42	}
	43
	44	static int hypervisor_set_time(unsigned long secs)
	45	{
	46	unsigned long ret;
	47	int retries = 10000;
	48
	49	retry:
	50	ret = sun4v_tod_set(secs);
	51	if (ret == HV_EOK)
	52	return 0;
	53	if (ret == HV_EWOULDBLOCK) {
	54	if (--retries > 0) {
	55	udelay(100);
	56	goto retry;
	57	}
	58	pr_warn("tod_set() timed out.\n");
	59	return -EAGAIN;
	60	}
	61	pr_warn("tod_set() not supported.\n");
	62	return -EOPNOTSUPP;
	63	}
	64
	65	static int sun4v_set_time(struct device dev, struct rtc_time tm)
	66	{
	67	unsigned long secs;
	68	int err;
	69
	70	err = rtc_tm_to_time(tm, &secs);
	71	if (err)
	72	return err;
	73
	74	return hypervisor_set_time(secs);
	75	}
	76
	77	static const struct rtc_class_ops sun4v_rtc_ops = {
	78	.read_time = sun4v_read_time,
	79	.set_time = sun4v_set_time,
	80	};
	81
	82	static int __init sun4v_rtc_probe(struct platform_device *pdev)
	83	{
	84	struct rtc_device *rtc;
	85
	86	rtc = devm_rtc_device_register(&pdev->dev, "sun4v",
	87	&sun4v_rtc_ops, THIS_MODULE);
	88	if (IS_ERR(rtc))
	89	return PTR_ERR(rtc);
	90
	91	platform_set_drvdata(pdev, rtc);
	92	return 0;
	93	}
	94
	95	static struct platform_driver sun4v_rtc_driver = {
	96	.driver = {
	97	.name = "rtc-sun4v",
	98	.owner = THIS_MODULE,
	99	},
	100	};
	101
	102	module_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);
	103
	104	MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
	105	MODULE_DESCRIPTION("SUN4V RTC driver");
	106	MODULE_LICENSE("GPL");