blob: 37dbee15769fdcb42bc9271e9de81991a79f1ffd [file] [log] [blame]
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +00001/*
2 * PowerNV Real Time Clock.
3 *
4 * Copyright 2011 IBM Corp.
5 *
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.
10 */
11
12
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>
Neelesh Gupta16b1d262014-10-14 14:08:36 +053018#include <linux/platform_device.h>
19#include <linux/of_platform.h>
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000020
21#include <asm/opal.h>
22#include <asm/firmware.h>
Michael Neuling2c491952013-11-29 14:22:48 +110023#include <asm/machdep.h>
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000024
25static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
26{
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);
34
35 GregorianDay(tm);
36}
37
38unsigned long __init opal_get_boot_time(void)
39{
40 struct rtc_time tm;
41 u32 y_m_d;
42 u64 h_m_s_ms;
Anton Blanchard6feff6d2013-09-23 12:05:05 +100043 __be32 __y_m_d;
44 __be64 __h_m_s_ms;
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000045 long rc = OPAL_BUSY;
46
Michael Neuling035ed262014-08-19 14:48:00 +100047 if (!opal_check_token(OPAL_RTC_READ))
Neelesh Gupta16b1d262014-10-14 14:08:36 +053048 return 0;
Michael Neuling035ed262014-08-19 14:48:00 +100049
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000050 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
Anton Blanchard6feff6d2013-09-23 12:05:05 +100051 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000052 if (rc == OPAL_BUSY_EVENT)
53 opal_poll_events(NULL);
54 else
55 mdelay(10);
56 }
Michael Neuling035ed262014-08-19 14:48:00 +100057 if (rc != OPAL_SUCCESS)
Neelesh Gupta16b1d262014-10-14 14:08:36 +053058 return 0;
Michael Neuling035ed262014-08-19 14:48:00 +100059
Anton Blanchard6feff6d2013-09-23 12:05:05 +100060 y_m_d = be32_to_cpu(__y_m_d);
61 h_m_s_ms = be64_to_cpu(__h_m_s_ms);
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000062 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);
65}
66
Neelesh Gupta16b1d262014-10-14 14:08:36 +053067static __init int opal_time_init(void)
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000068{
Neelesh Gupta16b1d262014-10-14 14:08:36 +053069 struct platform_device *pdev;
70 struct device_node *rtc;
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000071
Neelesh Gupta16b1d262014-10-14 14:08:36 +053072 rtc = of_find_node_by_path("/ibm,opal/rtc");
73 if (rtc) {
74 pdev = of_platform_device_create(rtc, "opal-rtc", NULL);
75 of_node_put(rtc);
76 } else {
77 if (opal_check_token(OPAL_RTC_READ) ||
78 opal_check_token(OPAL_READ_TPO))
79 pdev = platform_device_register_simple("opal-rtc", -1,
80 NULL, 0);
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000081 else
Neelesh Gupta16b1d262014-10-14 14:08:36 +053082 return -ENODEV;
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000083 }
Neelesh Gupta16b1d262014-10-14 14:08:36 +053084
85 return PTR_ERR_OR_ZERO(pdev);
Benjamin Herrenschmidt628daa82011-09-19 17:45:01 +000086}
Neelesh Gupta16b1d262014-10-14 14:08:36 +053087machine_subsys_initcall(powernv, opal_time_init);