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

/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
 *
 * Copyright (C) 2008 David S. Miller <[email protected]>
 */

#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;
		}
		printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
		return 0;
	}
	printk(KERN_WARNING "SUN4V: 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;
		}
		printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
		return -EAGAIN;
	}
	printk(KERN_WARNING "SUN4V: 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_device_register("sun4v", &pdev->dev,
				     &sun4v_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	platform_set_drvdata(pdev, rtc);
	return 0;
}

static int __exit sun4v_rtc_remove(struct platform_device *pdev)
{
	struct rtc_device *rtc = platform_get_drvdata(pdev);

	rtc_device_unregister(rtc);
	return 0;
}

static struct platform_driver sun4v_rtc_driver = {
	.driver		= {
		.name	= "rtc-sun4v",
		.owner	= THIS_MODULE,
	},
	.remove		= __exit_p(sun4v_rtc_remove),
};

static int __init sun4v_rtc_init(void)
{
	return platform_driver_probe(&sun4v_rtc_driver, sun4v_rtc_probe);
}

static void __exit sun4v_rtc_exit(void)
{
	platform_driver_unregister(&sun4v_rtc_driver);
}

module_init(sun4v_rtc_init);
module_exit(sun4v_rtc_exit);

MODULE_AUTHOR("David S. Miller <[email protected]>");
MODULE_DESCRIPTION("SUN4V RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
cecf61bd	1	/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
7a138ede DM	2	*
	3	* Copyright (C) 2008 David S. Miller <[email protected]>
	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/module.h>
	8	#include <linux/delay.h>
	9	#include <linux/init.h>
7a138ede DM	10	#include <linux/rtc.h>
	11	#include <linux/platform_device.h>
	12
	13	#include <asm/hypervisor.h>
	14
7a138ede DM	15	static unsigned long hypervisor_get_time(void)
	16	{
	17	unsigned long ret, time;
	18	int retries = 10000;
	19
	20	retry:
	21	ret = sun4v_tod_get(&time);
	22	if (ret == HV_EOK)
	23	return time;
	24	if (ret == HV_EWOULDBLOCK) {
	25	if (--retries > 0) {
	26	udelay(100);
	27	goto retry;
	28	}
	29	printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
	30	return 0;
	31	}
	32	printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
	33	return 0;
	34	}
	35
	36	static int sun4v_read_time(struct device dev, struct rtc_time tm)
	37	{
cecf61bd	38	rtc_time_to_tm(hypervisor_get_time(), tm);
7a138ede DM	39	return 0;
	40	}
	41
	42	static int hypervisor_set_time(unsigned long secs)
	43	{
	44	unsigned long ret;
	45	int retries = 10000;
	46
	47	retry:
	48	ret = sun4v_tod_set(secs);
	49	if (ret == HV_EOK)
	50	return 0;
	51	if (ret == HV_EWOULDBLOCK) {
	52	if (--retries > 0) {
	53	udelay(100);
	54	goto retry;
	55	}
	56	printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
	57	return -EAGAIN;
	58	}
	59	printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
	60	return -EOPNOTSUPP;
	61	}
	62
	63	static int sun4v_set_time(struct device dev, struct rtc_time tm)
	64	{
cecf61bd	65	unsigned long secs;
7a138ede DM	66	int err;
	67
	68	err = rtc_tm_to_time(tm, &secs);
	69	if (err)
	70	return err;
	71
cecf61bd	72	return hypervisor_set_time(secs);
7a138ede DM	73	}
	74
	75	static const struct rtc_class_ops sun4v_rtc_ops = {
	76	.read_time = sun4v_read_time,
	77	.set_time = sun4v_set_time,
	78	};
	79
cecf61bd	80	static int __init sun4v_rtc_probe(struct platform_device *pdev)
7a138ede	81	{
cecf61bd	82	struct rtc_device *rtc = rtc_device_register("sun4v", &pdev->dev,
7a138ede	83	&sun4v_rtc_ops, THIS_MODULE);
cecf61bd AZ	84	if (IS_ERR(rtc))
	85	return PTR_ERR(rtc);
	86
	87	platform_set_drvdata(pdev, rtc);
7a138ede DM	88	return 0;
	89	}
	90
cecf61bd	91	static int __exit sun4v_rtc_remove(struct platform_device *pdev)
7a138ede	92	{
cecf61bd	93	struct rtc_device *rtc = platform_get_drvdata(pdev);
7a138ede	94
cecf61bd	95	rtc_device_unregister(rtc);
7a138ede DM	96	return 0;
	97	}
	98
	99	static struct platform_driver sun4v_rtc_driver = {
	100	.driver = {
	101	.name = "rtc-sun4v",
	102	.owner = THIS_MODULE,
	103	},
cecf61bd	104	.remove = __exit_p(sun4v_rtc_remove),
7a138ede DM	105	};
	106
	107	static int __init sun4v_rtc_init(void)
	108	{
cecf61bd	109	return platform_driver_probe(&sun4v_rtc_driver, sun4v_rtc_probe);
7a138ede DM	110	}
	111
	112	static void __exit sun4v_rtc_exit(void)
	113	{
	114	platform_driver_unregister(&sun4v_rtc_driver);
	115	}
	116
	117	module_init(sun4v_rtc_init);
	118	module_exit(sun4v_rtc_exit);
cecf61bd AZ	119
	120	MODULE_AUTHOR("David S. Miller <[email protected]>");
	121	MODULE_DESCRIPTION("SUN4V RTC driver");
	122	MODULE_LICENSE("GPL");