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153 lines
3 KiB
C
153 lines
3 KiB
C
/* rtc-sun4c.c: Hypervisor based RTC for SUN4V systems.
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*
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* Copyright (C) 2008 David S. Miller <davem@davemloft.net>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/time.h>
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#include <linux/rtc.h>
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#include <linux/platform_device.h>
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#include <asm/hypervisor.h>
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MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
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MODULE_DESCRIPTION("SUN4V RTC driver");
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MODULE_LICENSE("GPL");
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struct sun4v_rtc {
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struct rtc_device *rtc;
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spinlock_t lock;
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};
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static unsigned long hypervisor_get_time(void)
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{
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unsigned long ret, time;
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int retries = 10000;
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retry:
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ret = sun4v_tod_get(&time);
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if (ret == HV_EOK)
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return time;
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if (ret == HV_EWOULDBLOCK) {
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if (--retries > 0) {
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udelay(100);
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goto retry;
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}
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printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
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return 0;
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}
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printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
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return 0;
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}
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static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct sun4v_rtc *p = dev_get_drvdata(dev);
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unsigned long flags, secs;
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spin_lock_irqsave(&p->lock, flags);
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secs = hypervisor_get_time();
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spin_unlock_irqrestore(&p->lock, flags);
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rtc_time_to_tm(secs, tm);
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return 0;
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}
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static int hypervisor_set_time(unsigned long secs)
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{
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unsigned long ret;
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int retries = 10000;
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retry:
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ret = sun4v_tod_set(secs);
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if (ret == HV_EOK)
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return 0;
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if (ret == HV_EWOULDBLOCK) {
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if (--retries > 0) {
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udelay(100);
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goto retry;
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}
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printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
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return -EAGAIN;
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}
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printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
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return -EOPNOTSUPP;
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}
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static int sun4v_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct sun4v_rtc *p = dev_get_drvdata(dev);
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unsigned long flags, secs;
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int err;
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err = rtc_tm_to_time(tm, &secs);
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if (err)
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return err;
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spin_lock_irqsave(&p->lock, flags);
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err = hypervisor_set_time(secs);
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spin_unlock_irqrestore(&p->lock, flags);
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return err;
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}
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static const struct rtc_class_ops sun4v_rtc_ops = {
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.read_time = sun4v_read_time,
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.set_time = sun4v_set_time,
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};
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static int __devinit sun4v_rtc_probe(struct platform_device *pdev)
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{
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struct sun4v_rtc *p = kzalloc(sizeof(*p), GFP_KERNEL);
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if (!p)
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return -ENOMEM;
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spin_lock_init(&p->lock);
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p->rtc = rtc_device_register("sun4v", &pdev->dev,
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&sun4v_rtc_ops, THIS_MODULE);
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if (IS_ERR(p->rtc)) {
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int err = PTR_ERR(p->rtc);
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kfree(p);
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return err;
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}
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platform_set_drvdata(pdev, p);
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return 0;
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}
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static int __devexit sun4v_rtc_remove(struct platform_device *pdev)
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{
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struct sun4v_rtc *p = platform_get_drvdata(pdev);
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rtc_device_unregister(p->rtc);
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kfree(p);
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return 0;
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}
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static struct platform_driver sun4v_rtc_driver = {
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.driver = {
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.name = "rtc-sun4v",
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.owner = THIS_MODULE,
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},
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.probe = sun4v_rtc_probe,
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.remove = __devexit_p(sun4v_rtc_remove),
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};
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static int __init sun4v_rtc_init(void)
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{
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return platform_driver_register(&sun4v_rtc_driver);
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}
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static void __exit sun4v_rtc_exit(void)
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{
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platform_driver_unregister(&sun4v_rtc_driver);
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}
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module_init(sun4v_rtc_init);
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module_exit(sun4v_rtc_exit);
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