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