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authorDavid S. Miller <davem@davemloft.net>2008-08-29 12:32:43 +0400
committerDavid S. Miller <davem@davemloft.net>2008-08-30 01:16:50 +0400
commit7a138ede551c5282c1b81d191bdd4aa989b119a8 (patch)
tree7f69cfeebdc6c4cddb9de8267ecddc68733cd163 /drivers/rtc
parent29b503f11cd648b3628be3a546f97da95a6670ce (diff)
downloadlinux-7a138ede551c5282c1b81d191bdd4aa989b119a8.tar.xz
rtc: Add Sun4V hypervisor RTC driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/Kconfig7
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/rtc-sun4v.c153
3 files changed, 161 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 5d600ff8d2dd..23403fae45a7 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -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
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index fed42c2f82fb..6850b04a9dd8 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -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
diff --git a/drivers/rtc/rtc-sun4v.c b/drivers/rtc/rtc-sun4v.c
new file mode 100644
index 000000000000..2012ccbb4a53
--- /dev/null
+++ b/drivers/rtc/rtc-sun4v.c
@@ -0,0 +1,153 @@
+/* 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);