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Commit 7a138ede authored by David S. Miller's avatar David S. Miller
Browse files

rtc: Add Sun4V hypervisor RTC driver. 



Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 29b503f1

drivers/rtc/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -592,4 +592,11 @@ config RTC_DRV_PPC 
	 the RTC. This exposes that functionality through the generic RTC

	 class.



config RTC_DRV_SUN4V

	bool "SUN4V Hypervisor RTC"

	depends on SPARC64

	help

	  If you say Y here you will get support for the Hypervisor

	  based RTC on SUN4V systems.



endif # RTC_CLASS

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o 
obj-$(CONFIG_RTC_DRV_M48T59)	+= rtc-m48t59.o

obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o

obj-$(CONFIG_RTC_DRV_BQ4802)	+= rtc-bq4802.o

obj-$(CONFIG_RTC_DRV_SUN4V)	+= rtc-sun4v.o

obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o

obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o

obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o

drivers/rtc/rtc-sun4v.c

0 → 100644
+153 −0
Original line number Diff line number Diff line 
/* rtc-sun4c.c: Hypervisor based RTC for SUN4V systems.

 *

 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>

 */



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/time.h>

#include <linux/rtc.h>

#include <linux/platform_device.h>



#include <asm/hypervisor.h>



MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");

MODULE_DESCRIPTION("SUN4V RTC driver");

MODULE_LICENSE("GPL");



struct sun4v_rtc {

	struct rtc_device	*rtc;

	spinlock_t		lock;

};



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)

{

	struct sun4v_rtc *p = dev_get_drvdata(dev);

	unsigned long flags, secs;



	spin_lock_irqsave(&p->lock, flags);

	secs = hypervisor_get_time();

	spin_unlock_irqrestore(&p->lock, flags);



	rtc_time_to_tm(secs, 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)

{

	struct sun4v_rtc *p = dev_get_drvdata(dev);

	unsigned long flags, secs;

	int err;



	err = rtc_tm_to_time(tm, &secs);

	if (err)

		return err;



	spin_lock_irqsave(&p->lock, flags);

	err = hypervisor_set_time(secs);

	spin_unlock_irqrestore(&p->lock, flags);



	return err;

}



static const struct rtc_class_ops sun4v_rtc_ops = {

	.read_time	= sun4v_read_time,

	.set_time	= sun4v_set_time,

};



static int __devinit sun4v_rtc_probe(struct platform_device *pdev)

{

	struct sun4v_rtc *p = kzalloc(sizeof(*p), GFP_KERNEL);



	if (!p)

		return -ENOMEM;



	spin_lock_init(&p->lock);



	p->rtc = rtc_device_register("sun4v", &pdev->dev,

				     &sun4v_rtc_ops, THIS_MODULE);

	if (IS_ERR(p->rtc)) {

		int err = PTR_ERR(p->rtc);

		kfree(p);

		return err;

	}

	platform_set_drvdata(pdev, p);

	return 0;

}



static int __devexit sun4v_rtc_remove(struct platform_device *pdev)

{

	struct sun4v_rtc *p = platform_get_drvdata(pdev);



	rtc_device_unregister(p->rtc);

	kfree(p);



	return 0;

}



static struct platform_driver sun4v_rtc_driver = {

	.driver		= {

		.name	= "rtc-sun4v",

		.owner	= THIS_MODULE,

	},

	.probe		= sun4v_rtc_probe,

	.remove		= __devexit_p(sun4v_rtc_remove),

};



static int __init sun4v_rtc_init(void)

{

	return platform_driver_register(&sun4v_rtc_driver);

}



static void __exit sun4v_rtc_exit(void)

{

	platform_driver_unregister(&sun4v_rtc_driver);

}



module_init(sun4v_rtc_init);

module_exit(sun4v_rtc_exit);