xref: /openbmc/u-boot/drivers/rtc/mvrtc.c (revision c978b524)
1 /*
2  * Copyright (C) 2011
3  * Jason Cooper <u-boot@lakedaemon.net>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * Date & Time support for Marvell Integrated RTC
10  */
11 
12 #include <common.h>
13 #include <command.h>
14 #include <rtc.h>
15 #include <asm/io.h>
16 #include "mvrtc.h"
17 
18 /* This RTC does not support century, so we assume 20 */
19 #define CENTURY 20
20 
21 int rtc_get(struct rtc_time *t)
22 {
23 	u32 time;
24 	u32 date;
25 	struct mvrtc_registers *mvrtc_regs;
26 
27 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
28 
29 	/* read the time register */
30 	time = readl(&mvrtc_regs->time);
31 
32 	/* read the date register */
33 	date = readl(&mvrtc_regs->date);
34 
35 	/* test for 12 hour clock (can't tell if it's am/pm) */
36 	if (time & MVRTC_HRFMT_MSK) {
37 		printf("Error: RTC in 12 hour mode, can't determine AM/PM.\n");
38 		return -1;
39 	}
40 
41 	/* time */
42 	t->tm_sec  = bcd2bin((time >> MVRTC_SEC_SFT)  & MVRTC_SEC_MSK);
43 	t->tm_min  = bcd2bin((time >> MVRTC_MIN_SFT)  & MVRTC_MIN_MSK);
44 	t->tm_hour = bcd2bin((time >> MVRTC_HOUR_SFT) & MVRTC_HOUR_MSK);
45 	t->tm_wday = bcd2bin((time >> MVRTC_DAY_SFT)  & MVRTC_DAY_MSK);
46 	t->tm_wday--;
47 
48 	/* date */
49 	t->tm_mday = bcd2bin((date >> MVRTC_DATE_SFT) & MVRTC_DATE_MSK);
50 	t->tm_mon  = bcd2bin((date >> MVRTC_MON_SFT)  & MVRTC_MON_MSK);
51 	t->tm_year = bcd2bin((date >> MVRTC_YEAR_SFT) & MVRTC_YEAR_MSK);
52 	t->tm_year += CENTURY * 100;
53 
54 	/* not supported in this RTC */
55 	t->tm_yday  = 0;
56 	t->tm_isdst = 0;
57 
58 	return 0;
59 }
60 
61 int rtc_set(struct rtc_time *t)
62 {
63 	u32 time = 0; /* sets hour format bit to zero, 24hr format. */
64 	u32 date = 0;
65 	struct mvrtc_registers *mvrtc_regs;
66 
67 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
68 
69 	/* check that this code isn't 80+ years old ;-) */
70 	if ((t->tm_year / 100) != CENTURY)
71 		printf("Warning: Only century %d supported.\n", CENTURY);
72 
73 	/* time */
74 	time |= (bin2bcd(t->tm_sec)      & MVRTC_SEC_MSK)  << MVRTC_SEC_SFT;
75 	time |= (bin2bcd(t->tm_min)      & MVRTC_MIN_MSK)  << MVRTC_MIN_SFT;
76 	time |= (bin2bcd(t->tm_hour)     & MVRTC_HOUR_MSK) << MVRTC_HOUR_SFT;
77 	time |= (bin2bcd(t->tm_wday + 1) & MVRTC_DAY_MSK)  << MVRTC_DAY_SFT;
78 
79 	/* date */
80 	date |= (bin2bcd(t->tm_mday)       & MVRTC_DATE_MSK) << MVRTC_DATE_SFT;
81 	date |= (bin2bcd(t->tm_mon)        & MVRTC_MON_MSK)  << MVRTC_MON_SFT;
82 	date |= (bin2bcd(t->tm_year % 100) & MVRTC_YEAR_MSK) << MVRTC_YEAR_SFT;
83 
84 	/* write the time register */
85 	writel(time, &mvrtc_regs->time);
86 
87 	/* write the date register */
88 	writel(date, &mvrtc_regs->date);
89 
90 	return 0;
91 }
92 
93 void rtc_reset(void)
94 {
95 	u32 time;
96 	u32 sec;
97 	struct mvrtc_registers *mvrtc_regs;
98 
99 	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
100 
101 	/* no init routine for this RTC needed, just check that it's working */
102 	time = readl(&mvrtc_regs->time);
103 	sec  = bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK);
104 	udelay(1000000);
105 	time = readl(&mvrtc_regs->time);
106 
107 	if (sec == bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK))
108 		printf("Error: RTC did not increment.\n");
109 }
110