Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / rtc / rtc-sun4v.c

diff --git a/kernel/drivers/rtc/rtc-sun4v.c b/kernel/drivers/rtc/rtc-sun4v.c
new file mode 100644 (file)
index 0000000..7c696c1
--- /dev/null
+++ b/kernel/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");