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