xref: /openbmc/u-boot/drivers/rtc/mxsrtc.c (revision ff9b0cb8)
1 /*
2  * Freescale i.MX28 RTC Driver
3  *
4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
5  * on behalf of DENX Software Engineering GmbH
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #include <common.h>
24 #include <rtc.h>
25 #include <asm/io.h>
26 #include <asm/arch/imx-regs.h>
27 #include <asm/arch/sys_proto.h>
28 
29 #define	MXS_RTC_MAX_TIMEOUT	1000000
30 
31 /* Set time in seconds since 1970-01-01 */
32 int mxs_rtc_set_time(uint32_t secs)
33 {
34 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
35 	int ret;
36 
37 	writel(secs, &rtc_regs->hw_rtc_seconds);
38 
39 	/*
40 	 * The 0x80 here means seconds were copied to analog. This information
41 	 * is taken from the linux kernel driver for the STMP37xx RTC since
42 	 * documentation doesn't mention it.
43 	 */
44 	ret = mxs_wait_mask_clr(&rtc_regs->hw_rtc_stat_reg,
45 		0x80 << RTC_STAT_STALE_REGS_OFFSET, MXS_RTC_MAX_TIMEOUT);
46 
47 	if (ret)
48 		printf("MXS RTC: Timeout waiting for update\n");
49 
50 	return ret;
51 }
52 
53 int rtc_get(struct rtc_time *time)
54 {
55 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
56 	uint32_t secs;
57 
58 	secs = readl(&rtc_regs->hw_rtc_seconds);
59 	to_tm(secs, time);
60 
61 	return 0;
62 }
63 
64 int rtc_set(struct rtc_time *time)
65 {
66 	uint32_t secs;
67 
68 	secs = mktime(time->tm_year, time->tm_mon, time->tm_mday,
69 		time->tm_hour, time->tm_min, time->tm_sec);
70 
71 	return mxs_rtc_set_time(secs);
72 }
73 
74 void rtc_reset(void)
75 {
76 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
77 	int ret;
78 
79 	/* Set time to 1970-01-01 */
80 	mxs_rtc_set_time(0);
81 
82 	/* Reset the RTC block */
83 	ret = mxs_reset_block(&rtc_regs->hw_rtc_ctrl_reg);
84 	if (ret)
85 		printf("MXS RTC: Block reset timeout\n");
86 }
87