summaryrefslogtreecommitdiff
path: root/drivers/rtc/rv8803.c
blob: acd50c656483a114c4ed19c8e3148624690ea3be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
// SPDX-License-Identifier: GPL-2.0+
/*
 * Date & Time support for Micro Crystal RV-8803-C7.
 *
 * based on ds1307.c which is
 *   (C) Copyright 2001, 2002, 2003
 *   Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *   Keith Outwater, keith_outwater@mvis.com`
 *   Steven Scholz, steven.scholz@imc-berlin.de
 *
 */

#include <common.h>
#include <command.h>
#include <dm.h>
#include <log.h>
#include <rtc.h>
#include <i2c.h>
#include <linux/bitops.h>

/*
 * RTC register addresses
 */
#define RTC_SEC_REG_ADDR	0x00
#define RTC_MIN_REG_ADDR	0x01
#define RTC_HR_REG_ADDR		0x02
#define RTC_DAY_REG_ADDR	0x03
#define RTC_DATE_REG_ADDR	0x04
#define RTC_MON_REG_ADDR	0x05
#define RTC_YR_REG_ADDR		0x06

#define RTC_FLAG_REG_ADDR	0x0E
#define RTC_FLAG_BIT_V1F	BIT(0)
#define RTC_FLAG_BIT_V2F	BIT(1)

#define RTC_CTL_REG_ADDR	0x0F
#define RTC_CTL_BIT_RST		BIT(0)

static int rv8803_rtc_set(struct udevice *dev, const struct rtc_time *tm)
{
	int ret;
	u8 buf[7];

	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
	      tm->tm_hour, tm->tm_min, tm->tm_sec);

	if (tm->tm_year < 2000 || tm->tm_year > 2099)
		printf("WARNING: year should be between 2000 and 2099!\n");

	buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
	buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
	buf[RTC_DAY_REG_ADDR] = 1 << (tm->tm_wday & 0x7);
	buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
	buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
	buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
	buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);

	ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
	if (ret < 0)
		return ret;

	return 0;
}

static int rv8803_rtc_get(struct udevice *dev, struct rtc_time *tm)
{
	int ret;
	u8 buf[7];
	int flags;

	flags = dm_i2c_reg_read(dev, RTC_FLAG_REG_ADDR);
	if (flags < 0)
		return flags;
	debug("%s: flags=%Xh\n", __func__, flags);

	if (flags & RTC_FLAG_BIT_V1F)
		printf("### Warning: temperature compensation has stopped\n");

	if (flags & RTC_FLAG_BIT_V2F) {
		printf("### Warning: Voltage low, data is invalid\n");
		return -1;
	}

	ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
	if (ret < 0)
		return ret;

	tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
	tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
	tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
	tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
	tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
	tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
	tm->tm_wday = fls(buf[RTC_DAY_REG_ADDR] & 0x7F) - 1;
	tm->tm_yday = 0;
	tm->tm_isdst = 0;

	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
	      tm->tm_hour, tm->tm_min, tm->tm_sec);

	return 0;
}

static int rv8803_rtc_reset(struct udevice *dev)
{
	int ret;
	struct rtc_time tmp = {
		.tm_year = 2000,
		.tm_mon = 1,
		.tm_mday = 1,
		.tm_hour = 0,
		.tm_min = 0,
		.tm_sec = 0,
	};

	/* assert reset */
	ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, RTC_CTL_BIT_RST);
	if (ret < 0)
		return ret;

	/* clear all flags */
	ret = dm_i2c_reg_write(dev, RTC_FLAG_REG_ADDR, 0);
	if (ret < 0)
		return ret;

	ret = rv8803_rtc_set(dev, &tmp);
	if (ret < 0)
		return ret;

	/* clear reset */
	ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 0);
	if (ret < 0)
		return ret;

	debug("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
	      tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
	      tmp.tm_hour, tmp.tm_min, tmp.tm_sec);

	return 0;
}

static int rv8803_probe(struct udevice *dev)
{
	i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
			   DM_I2C_CHIP_WR_ADDRESS);

	return 0;
}

static const struct rtc_ops rv8803_rtc_ops = {
	.get = rv8803_rtc_get,
	.set = rv8803_rtc_set,
	.reset = rv8803_rtc_reset,
};

static const struct udevice_id rv8803_rtc_ids[] = {
	{ .compatible = "microcrystal,rv8803", },
	{ }
};

U_BOOT_DRIVER(rtc_rv8803) = {
	.name	= "rtc-rv8803",
	.id	= UCLASS_RTC,
	.probe	= rv8803_probe,
	.of_match = rv8803_rtc_ids,
	.ops	= &rv8803_rtc_ops,
};