xref: /openbmc/u-boot/drivers/rtc/mxsrtc.c (revision fd697ecf)
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  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <rtc.h>
12 #include <asm/io.h>
13 #include <asm/arch/imx-regs.h>
14 #include <asm/arch/sys_proto.h>
15 
16 #define	MXS_RTC_MAX_TIMEOUT	1000000
17 
18 /* Set time in seconds since 1970-01-01 */
19 int mxs_rtc_set_time(uint32_t secs)
20 {
21 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
22 	int ret;
23 
24 	writel(secs, &rtc_regs->hw_rtc_seconds);
25 
26 	/*
27 	 * The 0x80 here means seconds were copied to analog. This information
28 	 * is taken from the linux kernel driver for the STMP37xx RTC since
29 	 * documentation doesn't mention it.
30 	 */
31 	ret = mxs_wait_mask_clr(&rtc_regs->hw_rtc_stat_reg,
32 		0x80 << RTC_STAT_STALE_REGS_OFFSET, MXS_RTC_MAX_TIMEOUT);
33 
34 	if (ret)
35 		printf("MXS RTC: Timeout waiting for update\n");
36 
37 	return ret;
38 }
39 
40 int rtc_get(struct rtc_time *time)
41 {
42 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
43 	uint32_t secs;
44 
45 	secs = readl(&rtc_regs->hw_rtc_seconds);
46 	to_tm(secs, time);
47 
48 	return 0;
49 }
50 
51 int rtc_set(struct rtc_time *time)
52 {
53 	uint32_t secs;
54 
55 	secs = mktime(time->tm_year, time->tm_mon, time->tm_mday,
56 		time->tm_hour, time->tm_min, time->tm_sec);
57 
58 	return mxs_rtc_set_time(secs);
59 }
60 
61 void rtc_reset(void)
62 {
63 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
64 	int ret;
65 
66 	/* Set time to 1970-01-01 */
67 	mxs_rtc_set_time(0);
68 
69 	/* Reset the RTC block */
70 	ret = mxs_reset_block(&rtc_regs->hw_rtc_ctrl_reg);
71 	if (ret)
72 		printf("MXS RTC: Block reset timeout\n");
73 }
74