rtc: Add Sun4V hypervisor RTC driver.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 5d600ff8d2dd235129ee3f746e15da735841e0ac..23403fae45a74505123bed763b2694a57c723f50 100644 (file)
--- 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 fed42c2f82fbbfcda4a00d51b67469a9dc2391b8..6850b04a9dd8878caf2f6538c1835fb1661e80a5 100644 (file)
--- 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 (file)
index 0000000..2012ccb
--- /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);