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 
opal_to_tm(u32 y_m_d,u64 h_m_s_ms,struct rtc_time * tm)22 static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
23 {
24 	tm->tm_year	= ((bcd2bin(y_m_d >> 24) * 100) +
25 			   bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
26 	tm->tm_mon	= bcd2bin((y_m_d >> 8) & 0xff) - 1;
27 	tm->tm_mday	= bcd2bin(y_m_d & 0xff);
28 	tm->tm_hour	= bcd2bin((h_m_s_ms >> 56) & 0xff);
29 	tm->tm_min	= bcd2bin((h_m_s_ms >> 48) & 0xff);
30 	tm->tm_sec	= bcd2bin((h_m_s_ms >> 40) & 0xff);
31 
32         GregorianDay(tm);
33 }
34 
opal_get_boot_time(void)35 unsigned long __init opal_get_boot_time(void)
36 {
37 	struct rtc_time tm;
38 	u32 y_m_d;
39 	u64 h_m_s_ms;
40 	long rc = OPAL_BUSY;
41 
42 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
43 		rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
44 		if (rc == OPAL_BUSY_EVENT)
45 			opal_poll_events(NULL);
46 		else
47 			mdelay(10);
48 	}
49 	if (rc != OPAL_SUCCESS)
50 		return 0;
51 	opal_to_tm(y_m_d, h_m_s_ms, &tm);
52 	return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
53 		      tm.tm_hour, tm.tm_min, tm.tm_sec);
54 }
55 
opal_get_rtc_time(struct rtc_time * tm)56 void opal_get_rtc_time(struct rtc_time *tm)
57 {
58 	long rc = OPAL_BUSY;
59 	u32 y_m_d;
60 	u64 h_m_s_ms;
61 
62 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
63 		rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
64 		if (rc == OPAL_BUSY_EVENT)
65 			opal_poll_events(NULL);
66 		else
67 			mdelay(10);
68 	}
69 	if (rc != OPAL_SUCCESS)
70 		return;
71 	opal_to_tm(y_m_d, h_m_s_ms, tm);
72 }
73 
opal_set_rtc_time(struct rtc_time * tm)74 int opal_set_rtc_time(struct rtc_time *tm)
75 {
76 	long rc = OPAL_BUSY;
77 	u32 y_m_d = 0;
78 	u64 h_m_s_ms = 0;
79 
80 	y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
81 	y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
82 	y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
83 	y_m_d |= ((u32)bin2bcd(tm->tm_mday));
84 
85 	h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
86 	h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
87 	h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
88 
89 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
90 		rc = opal_rtc_write(y_m_d, h_m_s_ms);
91 		if (rc == OPAL_BUSY_EVENT)
92 			opal_poll_events(NULL);
93 		else
94 			mdelay(10);
95 	}
96 	return rc == OPAL_SUCCESS ? 0 : -EIO;
97 }
98