rtc: Add Starfire platform RTC driver.

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

drivers/rtc/Kconfig

@@ -599,4 +599,11 @@ config RTC_DRV_SUN4V
 	  If you say Y here you will get support for the Hypervisor
 	  based RTC on SUN4V systems.
 
+config RTC_DRV_STARFIRE
+	bool "Starfire RTC"
+	depends on SPARC64
+	help
+	  If you say Y here you will get support for the RTC found on
+	  Starfire systems.
+
 endif # RTC_CLASS

drivers/rtc/Makefile

@@ -40,6 +40,7 @@ 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-$(CONFIG_RTC_DRV_STARFIRE)	+= rtc-starfire.o
 obj-$(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-starfire.c

+/* rtc-starfire.c: Starfire platform RTC driver.
+ *
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+
+#include <asm/oplib.h>
+
+MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
+MODULE_DESCRIPTION("Starfire RTC driver");
+MODULE_LICENSE("GPL");
+
+struct starfire_rtc {
+	struct rtc_device	*rtc;
+	spinlock_t		lock;
+};
+
+static u32 starfire_get_time(void)
+{
+	static char obp_gettod[32];
+	static u32 unix_tod;
+
+	sprintf(obp_gettod, "h# %08x unix-gettod",
+		(unsigned int) (long) &unix_tod);
+	prom_feval(obp_gettod);
+
+	return unix_tod;
+}
+
+static int starfire_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct starfire_rtc *p = dev_get_drvdata(dev);
+	unsigned long flags, secs;
+
+	spin_lock_irqsave(&p->lock, flags);
+	secs = starfire_get_time();
+	spin_unlock_irqrestore(&p->lock, flags);
+
+	rtc_time_to_tm(secs, tm);
+
+	return 0;
+}
+
+static int starfire_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;
+
+	/* Do nothing, time is set using the service processor
+	 * console on this platform.
+	 */
+	return 0;
+}
+
+static const struct rtc_class_ops starfire_rtc_ops = {
+	.read_time	= starfire_read_time,
+	.set_time	= starfire_set_time,
+};
+
+static int __devinit starfire_rtc_probe(struct platform_device *pdev)
+{
+	struct starfire_rtc *p = kzalloc(sizeof(*p), GFP_KERNEL);
+
+	if (!p)
+		return -ENOMEM;
+
+	spin_lock_init(&p->lock);
+
+	p->rtc = rtc_device_register("starfire", &pdev->dev,
+				     &starfire_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 starfire_rtc_remove(struct platform_device *pdev)
+{
+	struct starfire_rtc *p = platform_get_drvdata(pdev);
+
+	rtc_device_unregister(p->rtc);
+	kfree(p);
+
+	return 0;
+}
+
+static struct platform_driver starfire_rtc_driver = {
+	.driver		= {
+		.name	= "rtc-starfire",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= starfire_rtc_probe,
+	.remove		= __devexit_p(starfire_rtc_remove),
+};
+
+static int __init starfire_rtc_init(void)
+{
+	return platform_driver_register(&starfire_rtc_driver);
+}
+
+static void __exit starfire_rtc_exit(void)
+{
+	platform_driver_unregister(&starfire_rtc_driver);
+}
+
+module_init(starfire_rtc_init);
+module_exit(starfire_rtc_exit);