2 * PowerNV Real Time Clock.
4 * Copyright 2011 IBM Corp.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
13 #include <linux/kernel.h>
14 #include <linux/time.h>
15 #include <linux/bcd.h>
16 #include <linux/rtc.h>
17 #include <linux/delay.h>
18 #include <linux/platform_device.h>
19 #include <linux/of_platform.h>
22 #include <asm/firmware.h>
23 #include <asm/machdep.h>
25 static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
27 tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
28 bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
29 tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1;
30 tm->tm_mday = bcd2bin(y_m_d & 0xff);
31 tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
32 tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff);
33 tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);
38 unsigned long __init opal_get_boot_time(void)
47 if (!opal_check_token(OPAL_RTC_READ))
50 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
51 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
52 if (rc == OPAL_BUSY_EVENT)
53 opal_poll_events(NULL);
57 if (rc != OPAL_SUCCESS)
60 y_m_d = be32_to_cpu(__y_m_d);
61 h_m_s_ms = be64_to_cpu(__h_m_s_ms);
62 opal_to_tm(y_m_d, h_m_s_ms, &tm);
63 return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
64 tm.tm_hour, tm.tm_min, tm.tm_sec);
67 static __init int opal_time_init(void)
69 struct platform_device *pdev;
70 struct device_node *rtc;
72 rtc = of_find_node_by_path("/ibm,opal/rtc");
74 pdev = of_platform_device_create(rtc, "opal-rtc", NULL);
77 if (opal_check_token(OPAL_RTC_READ) ||
78 opal_check_token(OPAL_READ_TPO))
79 pdev = platform_device_register_simple("opal-rtc", -1,
85 return PTR_ERR_OR_ZERO(pdev);
87 machine_subsys_initcall(powernv, opal_time_init);