#include <linux/bcd.h>
 #include <linux/rtc.h>
 #include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
 
 #include <asm/opal.h>
 #include <asm/firmware.h>
        long rc = OPAL_BUSY;
 
        if (!opal_check_token(OPAL_RTC_READ))
-               goto out;
+               return 0;
 
        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
                rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
                        mdelay(10);
        }
        if (rc != OPAL_SUCCESS)
-               goto out;
+               return 0;
 
        y_m_d = be32_to_cpu(__y_m_d);
        h_m_s_ms = be64_to_cpu(__h_m_s_ms);
        opal_to_tm(y_m_d, h_m_s_ms, &tm);
        return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
                      tm.tm_hour, tm.tm_min, tm.tm_sec);
-out:
-       ppc_md.get_rtc_time = NULL;
-       ppc_md.set_rtc_time = NULL;
-       return 0;
 }
 
-void opal_get_rtc_time(struct rtc_time *tm)
+static __init int opal_time_init(void)
 {
-       long rc = OPAL_BUSY;
-       u32 y_m_d;
-       u64 h_m_s_ms;
-       __be32 __y_m_d;
-       __be64 __h_m_s_ms;
+       struct platform_device *pdev;
+       struct device_node *rtc;
 
-       while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
-               rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
-               if (rc == OPAL_BUSY_EVENT)
-                       opal_poll_events(NULL);
+       rtc = of_find_node_by_path("/ibm,opal/rtc");
+       if (rtc) {
+               pdev = of_platform_device_create(rtc, "opal-rtc", NULL);
+               of_node_put(rtc);
+       } else {
+               if (opal_check_token(OPAL_RTC_READ) ||
+                   opal_check_token(OPAL_READ_TPO))
+                       pdev = platform_device_register_simple("opal-rtc", -1,
+                                                              NULL, 0);
                else
-                       mdelay(10);
+                       return -ENODEV;
        }
-       if (rc != OPAL_SUCCESS)
-               return;
-       y_m_d = be32_to_cpu(__y_m_d);
-       h_m_s_ms = be64_to_cpu(__h_m_s_ms);
-       opal_to_tm(y_m_d, h_m_s_ms, tm);
-}
-
-int opal_set_rtc_time(struct rtc_time *tm)
-{
-       long rc = OPAL_BUSY;
-       u32 y_m_d = 0;
-       u64 h_m_s_ms = 0;
-
-       y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
-       y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
-       y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
-       y_m_d |= ((u32)bin2bcd(tm->tm_mday));
-
-       h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
-       h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
-       h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
 
-       while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
-               rc = opal_rtc_write(y_m_d, h_m_s_ms);
-               if (rc == OPAL_BUSY_EVENT)
-                       opal_poll_events(NULL);
-               else
-                       mdelay(10);
-       }
-       return rc == OPAL_SUCCESS ? 0 : -EIO;
+       return PTR_ERR_OR_ZERO(pdev);
 }
+machine_subsys_initcall(powernv, opal_time_init);
 
--- /dev/null
+/*
+ * IBM OPAL RTC driver
+ * Copyright (C) 2014 IBM
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ */
+
+#define DRVNAME                "rtc-opal"
+#define pr_fmt(fmt)    DRVNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
+{
+       tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
+                      bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
+       tm->tm_mon  = bcd2bin((y_m_d >> 8) & 0xff) - 1;
+       tm->tm_mday = bcd2bin(y_m_d & 0xff);
+       tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
+       tm->tm_min  = bcd2bin((h_m_s_ms >> 48) & 0xff);
+       tm->tm_sec  = bcd2bin((h_m_s_ms >> 40) & 0xff);
+
+       GregorianDay(tm);
+}
+
+static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms)
+{
+       *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
+       *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
+       *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
+       *y_m_d |= ((u32)bin2bcd(tm->tm_mday));
+
+       *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
+       *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
+       *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
+}
+
+static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+       long rc = OPAL_BUSY;
+       u32 y_m_d;
+       u64 h_m_s_ms;
+       __be32 __y_m_d;
+       __be64 __h_m_s_ms;
+
+       while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+               rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
+               if (rc == OPAL_BUSY_EVENT)
+                       opal_poll_events(NULL);
+               else
+                       msleep(10);
+       }
+
+       if (rc != OPAL_SUCCESS)
+               return -EIO;
+
+       y_m_d = be32_to_cpu(__y_m_d);
+       h_m_s_ms = be64_to_cpu(__h_m_s_ms);
+       opal_to_tm(y_m_d, h_m_s_ms, tm);
+
+       return 0;
+}
+
+static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm)
+{
+       long rc = OPAL_BUSY;
+       u32 y_m_d = 0;
+       u64 h_m_s_ms = 0;
+
+       tm_to_opal(tm, &y_m_d, &h_m_s_ms);
+       while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+               rc = opal_rtc_write(y_m_d, h_m_s_ms);
+               if (rc == OPAL_BUSY_EVENT)
+                       opal_poll_events(NULL);
+               else
+                       msleep(10);
+       }
+
+       return rc == OPAL_SUCCESS ? 0 : -EIO;
+}
+
+/*
+ * TPO Timed Power-On
+ *
+ * TPO get/set OPAL calls care about the hour and min and to make it consistent
+ * with the rtc utility time conversion functions, we use the 'u64' to store
+ * its value and perform bit shift by 32 before use..
+ */
+static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       __be32 __y_m_d, __h_m;
+       struct opal_msg msg;
+       int rc, token;
+       u64 h_m_s_ms;
+       u32 y_m_d;
+
+       token = opal_async_get_token_interruptible();
+       if (token < 0) {
+               if (token != -ERESTARTSYS)
+                       pr_err("Failed to get the async token\n");
+
+               return token;
+       }
+
+       rc = opal_tpo_read(token, &__y_m_d, &__h_m);
+       if (rc != OPAL_ASYNC_COMPLETION) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       rc = opal_async_wait_response(token, &msg);
+       if (rc) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       rc = be64_to_cpu(msg.params[1]);
+       if (rc != OPAL_SUCCESS) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       y_m_d = be32_to_cpu(__y_m_d);
+       h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32);
+       opal_to_tm(y_m_d, h_m_s_ms, &alarm->time);
+
+exit:
+       opal_async_release_token(token);
+       return rc;
+}
+
+/* Set Timed Power-On */
+static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       u64 h_m_s_ms = 0, token;
+       struct opal_msg msg;
+       u32 y_m_d = 0;
+       int rc;
+
+       tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);
+
+       token = opal_async_get_token_interruptible();
+       if (token < 0) {
+               if (token != -ERESTARTSYS)
+                       pr_err("Failed to get the async token\n");
+
+               return token;
+       }
+
+       /* TPO, we care about hour and minute */
+       rc = opal_tpo_write(token, y_m_d,
+                           (u32)((h_m_s_ms >> 32) & 0xffff0000));
+       if (rc != OPAL_ASYNC_COMPLETION) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       rc = opal_async_wait_response(token, &msg);
+       if (rc) {
+               rc = -EIO;
+               goto exit;
+       }
+
+       rc = be64_to_cpu(msg.params[1]);
+       if (rc != OPAL_SUCCESS)
+               rc = -EIO;
+
+exit:
+       opal_async_release_token(token);
+       return rc;
+}
+
+static const struct rtc_class_ops opal_rtc_ops = {
+       .read_time      = opal_get_rtc_time,
+       .set_time       = opal_set_rtc_time,
+       .read_alarm     = opal_get_tpo_time,
+       .set_alarm      = opal_set_tpo_time,
+};
+
+static int opal_rtc_probe(struct platform_device *pdev)
+{
+       struct rtc_device *rtc;
+
+       if (pdev->dev.of_node && of_get_property(pdev->dev.of_node, "has-tpo",
+                                                NULL))
+               device_set_wakeup_capable(&pdev->dev, true);
+
+       rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops,
+                                      THIS_MODULE);
+       if (IS_ERR(rtc))
+               return PTR_ERR(rtc);
+
+       rtc->uie_unsupported = 1;
+
+       return 0;
+}
+
+static const struct of_device_id opal_rtc_match[] = {
+       {
+               .compatible     = "ibm,opal-rtc",
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(of, opal_rtc_match);
+
+static const struct platform_device_id opal_rtc_driver_ids[] = {
+       {
+               .name           = "opal-rtc",
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids);
+
+static struct platform_driver opal_rtc_driver = {
+       .probe          = opal_rtc_probe,
+       .id_table       = opal_rtc_driver_ids,
+       .driver         = {
+               .name           = DRVNAME,
+               .owner          = THIS_MODULE,
+               .of_match_table = opal_rtc_match,
+       },
+};
+
+static int __init opal_rtc_init(void)
+{
+       if (!firmware_has_feature(FW_FEATURE_OPAL))
+               return -ENODEV;
+
+       return platform_driver_register(&opal_rtc_driver);
+}
+
+static void __exit opal_rtc_exit(void)
+{
+       platform_driver_unregister(&opal_rtc_driver);
+}
+
+MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("IBM OPAL RTC driver");
+MODULE_LICENSE("GPL");
+
+module_init(opal_rtc_init);
+module_exit(opal_rtc_exit);