xref: /openbmc/u-boot/drivers/rtc/mvrtc.c (revision 472d5460)
1 /*
2  * Copyright (C) 2011
3  * Jason Cooper <u-boot@lakedaemon.net>
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 /*
25  * Date & Time support for Marvell Integrated RTC
26  */
27 
28 #include <common.h>
29 #include <command.h>
30 #include <rtc.h>
31 #include <asm/io.h>
32 #include "mvrtc.h"
33 
34 /* This RTC does not support century, so we assume 20 */
35 #define CENTURY 20
36 
37 int rtc_get(struct rtc_time *t)
38 {
39 	u32 time;
40 	u32 date;
41 	struct mvrtc_registers *mvrtc_regs;
42 
43 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
44 
45 	/* read the time register */
46 	time = readl(&mvrtc_regs->time);
47 
48 	/* read the date register */
49 	date = readl(&mvrtc_regs->date);
50 
51 	/* test for 12 hour clock (can't tell if it's am/pm) */
52 	if (time & MVRTC_HRFMT_MSK) {
53 		printf("Error: RTC in 12 hour mode, can't determine AM/PM.\n");
54 		return -1;
55 	}
56 
57 	/* time */
58 	t->tm_sec  = bcd2bin((time >> MVRTC_SEC_SFT)  & MVRTC_SEC_MSK);
59 	t->tm_min  = bcd2bin((time >> MVRTC_MIN_SFT)  & MVRTC_MIN_MSK);
60 	t->tm_hour = bcd2bin((time >> MVRTC_HOUR_SFT) & MVRTC_HOUR_MSK);
61 	t->tm_wday = bcd2bin((time >> MVRTC_DAY_SFT)  & MVRTC_DAY_MSK);
62 	t->tm_wday--;
63 
64 	/* date */
65 	t->tm_mday = bcd2bin((date >> MVRTC_DATE_SFT) & MVRTC_DATE_MSK);
66 	t->tm_mon  = bcd2bin((date >> MVRTC_MON_SFT)  & MVRTC_MON_MSK);
67 	t->tm_year = bcd2bin((date >> MVRTC_YEAR_SFT) & MVRTC_YEAR_MSK);
68 	t->tm_year += CENTURY * 100;
69 
70 	/* not supported in this RTC */
71 	t->tm_yday  = 0;
72 	t->tm_isdst = 0;
73 
74 	return 0;
75 }
76 
77 int rtc_set(struct rtc_time *t)
78 {
79 	u32 time = 0; /* sets hour format bit to zero, 24hr format. */
80 	u32 date = 0;
81 	struct mvrtc_registers *mvrtc_regs;
82 
83 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
84 
85 	/* check that this code isn't 80+ years old ;-) */
86 	if ((t->tm_year / 100) != CENTURY)
87 		printf("Warning: Only century %d supported.\n", CENTURY);
88 
89 	/* time */
90 	time |= (bin2bcd(t->tm_sec)      & MVRTC_SEC_MSK)  << MVRTC_SEC_SFT;
91 	time |= (bin2bcd(t->tm_min)      & MVRTC_MIN_MSK)  << MVRTC_MIN_SFT;
92 	time |= (bin2bcd(t->tm_hour)     & MVRTC_HOUR_MSK) << MVRTC_HOUR_SFT;
93 	time |= (bin2bcd(t->tm_wday + 1) & MVRTC_DAY_MSK)  << MVRTC_DAY_SFT;
94 
95 	/* date */
96 	date |= (bin2bcd(t->tm_mday)       & MVRTC_DATE_MSK) << MVRTC_DATE_SFT;
97 	date |= (bin2bcd(t->tm_mon)        & MVRTC_MON_MSK)  << MVRTC_MON_SFT;
98 	date |= (bin2bcd(t->tm_year % 100) & MVRTC_YEAR_MSK) << MVRTC_YEAR_SFT;
99 
100 	/* write the time register */
101 	writel(time, &mvrtc_regs->time);
102 
103 	/* write the date register */
104 	writel(date, &mvrtc_regs->date);
105 
106 	return 0;
107 }
108 
109 void rtc_reset(void)
110 {
111 	u32 time;
112 	u32 sec;
113 	struct mvrtc_registers *mvrtc_regs;
114 
115 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
116 
117 	/* no init routine for this RTC needed, just check that it's working */
118 	time = readl(&mvrtc_regs->time);
119 	sec  = bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK);
120 	udelay(1000000);
121 	time = readl(&mvrtc_regs->time);
122 
123 	if (sec == bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK))
124 		printf("Error: RTC did not increment.\n");
125 }
126