1/*
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>
18
19#include <asm/opal.h>
20#include <asm/firmware.h>
21#include <asm/machdep.h>
22
23static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
24{
25	tm->tm_year	= ((bcd2bin(y_m_d >> 24) * 100) +
26			   bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
27	tm->tm_mon	= bcd2bin((y_m_d >> 8) & 0xff) - 1;
28	tm->tm_mday	= bcd2bin(y_m_d & 0xff);
29	tm->tm_hour	= bcd2bin((h_m_s_ms >> 56) & 0xff);
30	tm->tm_min	= bcd2bin((h_m_s_ms >> 48) & 0xff);
31	tm->tm_sec	= bcd2bin((h_m_s_ms >> 40) & 0xff);
32
33        GregorianDay(tm);
34}
35
36unsigned long __init opal_get_boot_time(void)
37{
38	struct rtc_time tm;
39	u32 y_m_d;
40	u64 h_m_s_ms;
41	__be32 __y_m_d;
42	__be64 __h_m_s_ms;
43	long rc = OPAL_BUSY;
44
45	if (!opal_check_token(OPAL_RTC_READ))
46		goto out;
47
48	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
49		rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
50		if (rc == OPAL_BUSY_EVENT)
51			opal_poll_events(NULL);
52		else
53			mdelay(10);
54	}
55	if (rc != OPAL_SUCCESS)
56		goto out;
57
58	y_m_d = be32_to_cpu(__y_m_d);
59	h_m_s_ms = be64_to_cpu(__h_m_s_ms);
60	opal_to_tm(y_m_d, h_m_s_ms, &tm);
61	return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
62		      tm.tm_hour, tm.tm_min, tm.tm_sec);
63out:
64	ppc_md.get_rtc_time = NULL;
65	ppc_md.set_rtc_time = NULL;
66	return 0;
67}
68
69void opal_get_rtc_time(struct rtc_time *tm)
70{
71	long rc = OPAL_BUSY;
72	u32 y_m_d;
73	u64 h_m_s_ms;
74	__be32 __y_m_d;
75	__be64 __h_m_s_ms;
76
77	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
78		rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
79		if (rc == OPAL_BUSY_EVENT)
80			opal_poll_events(NULL);
81		else
82			mdelay(10);
83	}
84	if (rc != OPAL_SUCCESS)
85		return;
86	y_m_d = be32_to_cpu(__y_m_d);
87	h_m_s_ms = be64_to_cpu(__h_m_s_ms);
88	opal_to_tm(y_m_d, h_m_s_ms, tm);
89}
90
91int opal_set_rtc_time(struct rtc_time *tm)
92{
93	long rc = OPAL_BUSY;
94	u32 y_m_d = 0;
95	u64 h_m_s_ms = 0;
96
97	y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
98	y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
99	y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
100	y_m_d |= ((u32)bin2bcd(tm->tm_mday));
101
102	h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
103	h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
104	h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
105
106	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
107		rc = opal_rtc_write(y_m_d, h_m_s_ms);
108		if (rc == OPAL_BUSY_EVENT)
109			opal_poll_events(NULL);
110		else
111			mdelay(10);
112	}
113	return rc == OPAL_SUCCESS ? 0 : -EIO;
114}
115