1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sun4v.c b/drivers/rtc/rtc-sun4v.c
new file mode 100644
index 000000000..7c696c12f
--- /dev/null
+++ b/drivers/rtc/rtc-sun4v.c
@@ -0,0 +1,105 @@
+/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.
+ *
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+
+#include <asm/hypervisor.h>
+
+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;
+		}
+		pr_warn("tod_get() timed out.\n");
+		return 0;
+	}
+	pr_warn("tod_get() not supported.\n");
+	return 0;
+}
+
+static int sun4v_read_time(struct device *dev, struct rtc_time *tm)
+{
+	rtc_time_to_tm(hypervisor_get_time(), 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;
+		}
+		pr_warn("tod_set() timed out.\n");
+		return -EAGAIN;
+	}
+	pr_warn("tod_set() not supported.\n");
+	return -EOPNOTSUPP;
+}
+
+static int sun4v_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;
+
+	return hypervisor_set_time(secs);
+}
+
+static const struct rtc_class_ops sun4v_rtc_ops = {
+	.read_time	= sun4v_read_time,
+	.set_time	= sun4v_set_time,
+};
+
+static int __init sun4v_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+
+	rtc = devm_rtc_device_register(&pdev->dev, "sun4v",
+				&sun4v_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	platform_set_drvdata(pdev, rtc);
+	return 0;
+}
+
+static struct platform_driver sun4v_rtc_driver = {
+	.driver		= {
+		.name	= "rtc-sun4v",
+	},
+};
+
+module_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe);
+
+MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
+MODULE_DESCRIPTION("SUN4V RTC driver");
+MODULE_LICENSE("GPL");