1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Freescale i.MX28 RTC Driver
4  *
5  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
6  * on behalf of DENX Software Engineering GmbH
7  */
8 
9 #include <common.h>
10 #include <rtc.h>
11 #include <asm/io.h>
12 #include <asm/arch/imx-regs.h>
13 #include <asm/arch/sys_proto.h>
14 
15 #define	MXS_RTC_MAX_TIMEOUT	1000000
16 
17 /* Set time in seconds since 1970-01-01 */
mxs_rtc_set_time(uint32_t secs)18 int mxs_rtc_set_time(uint32_t secs)
19 {
20 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
21 	int ret;
22 
23 	writel(secs, &rtc_regs->hw_rtc_seconds);
24 
25 	/*
26 	 * The 0x80 here means seconds were copied to analog. This information
27 	 * is taken from the linux kernel driver for the STMP37xx RTC since
28 	 * documentation doesn't mention it.
29 	 */
30 	ret = mxs_wait_mask_clr(&rtc_regs->hw_rtc_stat_reg,
31 		0x80 << RTC_STAT_STALE_REGS_OFFSET, MXS_RTC_MAX_TIMEOUT);
32 
33 	if (ret)
34 		printf("MXS RTC: Timeout waiting for update\n");
35 
36 	return ret;
37 }
38 
rtc_get(struct rtc_time * time)39 int rtc_get(struct rtc_time *time)
40 {
41 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
42 	uint32_t secs;
43 
44 	secs = readl(&rtc_regs->hw_rtc_seconds);
45 	rtc_to_tm(secs, time);
46 
47 	return 0;
48 }
49 
rtc_set(struct rtc_time * time)50 int rtc_set(struct rtc_time *time)
51 {
52 	uint32_t secs;
53 
54 	secs = rtc_mktime(time);
55 
56 	return mxs_rtc_set_time(secs);
57 }
58 
rtc_reset(void)59 void rtc_reset(void)
60 {
61 	struct mxs_rtc_regs *rtc_regs = (struct mxs_rtc_regs *)MXS_RTC_BASE;
62 	int ret;
63 
64 	/* Set time to 1970-01-01 */
65 	mxs_rtc_set_time(0);
66 
67 	/* Reset the RTC block */
68 	ret = mxs_reset_block(&rtc_regs->hw_rtc_ctrl_reg);
69 	if (ret)
70 		printf("MXS RTC: Block reset timeout\n");
71 }
72