xref: /openbmc/u-boot/drivers/rtc/mvrtc.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2011
4  * Jason Cooper <u-boot@lakedaemon.net>
5  */
6 
7 /*
8  * Date & Time support for Marvell Integrated RTC
9  */
10 
11 #include <common.h>
12 #include <command.h>
13 #include <rtc.h>
14 #include <asm/io.h>
15 #include "mvrtc.h"
16 
17 /* This RTC does not support century, so we assume 20 */
18 #define CENTURY 20
19 
20 int rtc_get(struct rtc_time *t)
21 {
22 	u32 time;
23 	u32 date;
24 	struct mvrtc_registers *mvrtc_regs;
25 
26 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
27 
28 	/* read the time register */
29 	time = readl(&mvrtc_regs->time);
30 
31 	/* read the date register */
32 	date = readl(&mvrtc_regs->date);
33 
34 	/* test for 12 hour clock (can't tell if it's am/pm) */
35 	if (time & MVRTC_HRFMT_MSK) {
36 		printf("Error: RTC in 12 hour mode, can't determine AM/PM.\n");
37 		return -1;
38 	}
39 
40 	/* time */
41 	t->tm_sec  = bcd2bin((time >> MVRTC_SEC_SFT)  & MVRTC_SEC_MSK);
42 	t->tm_min  = bcd2bin((time >> MVRTC_MIN_SFT)  & MVRTC_MIN_MSK);
43 	t->tm_hour = bcd2bin((time >> MVRTC_HOUR_SFT) & MVRTC_HOUR_MSK);
44 	t->tm_wday = bcd2bin((time >> MVRTC_DAY_SFT)  & MVRTC_DAY_MSK);
45 	t->tm_wday--;
46 
47 	/* date */
48 	t->tm_mday = bcd2bin((date >> MVRTC_DATE_SFT) & MVRTC_DATE_MSK);
49 	t->tm_mon  = bcd2bin((date >> MVRTC_MON_SFT)  & MVRTC_MON_MSK);
50 	t->tm_year = bcd2bin((date >> MVRTC_YEAR_SFT) & MVRTC_YEAR_MSK);
51 	t->tm_year += CENTURY * 100;
52 
53 	/* not supported in this RTC */
54 	t->tm_yday  = 0;
55 	t->tm_isdst = 0;
56 
57 	return 0;
58 }
59 
60 int rtc_set(struct rtc_time *t)
61 {
62 	u32 time = 0; /* sets hour format bit to zero, 24hr format. */
63 	u32 date = 0;
64 	struct mvrtc_registers *mvrtc_regs;
65 
66 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
67 
68 	/* check that this code isn't 80+ years old ;-) */
69 	if ((t->tm_year / 100) != CENTURY)
70 		printf("Warning: Only century %d supported.\n", CENTURY);
71 
72 	/* time */
73 	time |= (bin2bcd(t->tm_sec)      & MVRTC_SEC_MSK)  << MVRTC_SEC_SFT;
74 	time |= (bin2bcd(t->tm_min)      & MVRTC_MIN_MSK)  << MVRTC_MIN_SFT;
75 	time |= (bin2bcd(t->tm_hour)     & MVRTC_HOUR_MSK) << MVRTC_HOUR_SFT;
76 	time |= (bin2bcd(t->tm_wday + 1) & MVRTC_DAY_MSK)  << MVRTC_DAY_SFT;
77 
78 	/* date */
79 	date |= (bin2bcd(t->tm_mday)       & MVRTC_DATE_MSK) << MVRTC_DATE_SFT;
80 	date |= (bin2bcd(t->tm_mon)        & MVRTC_MON_MSK)  << MVRTC_MON_SFT;
81 	date |= (bin2bcd(t->tm_year % 100) & MVRTC_YEAR_MSK) << MVRTC_YEAR_SFT;
82 
83 	/* write the time register */
84 	writel(time, &mvrtc_regs->time);
85 
86 	/* write the date register */
87 	writel(date, &mvrtc_regs->date);
88 
89 	return 0;
90 }
91 
92 void rtc_reset(void)
93 {
94 	u32 time;
95 	u32 sec;
96 	struct mvrtc_registers *mvrtc_regs;
97 
98 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
99 
100 	/* no init routine for this RTC needed, just check that it's working */
101 	time = readl(&mvrtc_regs->time);
102 	sec  = bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK);
103 	udelay(1000000);
104 	time = readl(&mvrtc_regs->time);
105 
106 	if (sec == bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK))
107 		printf("Error: RTC did not increment.\n");
108 }
109