aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rv3029.c
blob: f08040a8599a201b2b9c7727d23415be3b9bbfc1 (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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/*
 * (C) Copyright 2010
 * Heiko Schocher, DENX Software Engineering, hs@denx.de
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <command.h>
#include <i2c.h>
#include <rtc.h>

#define RTC_RV3029_CTRL1	0x00
#define RTC_RV3029_CTRL1_EERE	(1 << 3)

#define RTC_RV3029_CTRL_STATUS	0x03
#define RTC_RV3029_CTRLS_EEBUSY	(1 << 7)

#define RTC_RV3029_CTRL_RESET	0x04
#define RTC_RV3029_CTRL_SYS_R	(1 << 4)

#define RTC_RV3029_CLOCK_PAGE	0x08
#define RTC_RV3029_PAGE_LEN	7

#define RV3029C2_W_SECONDS	0x00
#define RV3029C2_W_MINUTES	0x01
#define RV3029C2_W_HOURS	0x02
#define RV3029C2_W_DATE		0x03
#define RV3029C2_W_DAYS		0x04
#define RV3029C2_W_MONTHS	0x05
#define RV3029C2_W_YEARS	0x06

#define RV3029C2_REG_HR_12_24          (1 << 6)  /* 24h/12h mode */
#define RV3029C2_REG_HR_PM             (1 << 5)  /* PM/AM bit in 12h mode */

#define RTC_RV3029_EEPROM_CTRL	0x30
#define RTC_RV3029_TRICKLE_1K	(1 << 4)
#define RTC_RV3029_TRICKLE_5K	(1 << 5)
#define RTC_RV3029_TRICKLE_20K	(1 << 6)
#define RTC_RV3029_TRICKLE_80K	(1 << 7)

int rtc_get( struct rtc_time *tmp )
{
	int	ret;
	unsigned char buf[RTC_RV3029_PAGE_LEN];

	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1, buf, \
			RTC_RV3029_PAGE_LEN);
	if (ret) {
		printf("%s: error reading RTC: %x\n", __func__, ret);
		return -1;
	}
	tmp->tm_sec  = bcd2bin( buf[RV3029C2_W_SECONDS] & 0x7f);
	tmp->tm_min  = bcd2bin( buf[RV3029C2_W_MINUTES] & 0x7f);
	if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_12_24) {
		/* 12h format */
		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x1f);
		if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_PM)
			/* PM flag set */
			tmp->tm_hour += 12;
	} else
		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x3f);

	tmp->tm_mday = bcd2bin( buf[RV3029C2_W_DATE] & 0x3F );
	tmp->tm_mon  = bcd2bin( buf[RV3029C2_W_MONTHS] & 0x1F );
	tmp->tm_wday = bcd2bin( buf[RV3029C2_W_DAYS] & 0x07 );
	/* RTC supports only years > 1999 */
	tmp->tm_year = bcd2bin( buf[RV3029C2_W_YEARS]) + 2000;
	tmp->tm_yday = 0;
	tmp->tm_isdst = 0;

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

	return 0;
}

int rtc_set( struct rtc_time *tmp )
{
	int	ret;
	unsigned char buf[RTC_RV3029_PAGE_LEN];

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

	if (tmp->tm_year < 2000) {
		printf("RTC: year %d < 2000 not possible\n", tmp->tm_year);
		return -1;
	}
	buf[RV3029C2_W_SECONDS] = bin2bcd(tmp->tm_sec);
	buf[RV3029C2_W_MINUTES] = bin2bcd(tmp->tm_min);
	buf[RV3029C2_W_HOURS] = bin2bcd(tmp->tm_hour);
	/* set 24h format */
	buf[RV3029C2_W_HOURS] &= ~RV3029C2_REG_HR_12_24;
	buf[RV3029C2_W_DATE] = bin2bcd(tmp->tm_mday);
	buf[RV3029C2_W_DAYS] = bin2bcd(tmp->tm_wday);
	buf[RV3029C2_W_MONTHS] = bin2bcd(tmp->tm_mon);
	tmp->tm_year -= 2000;
	buf[RV3029C2_W_YEARS] = bin2bcd(tmp->tm_year);
	ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1,
			buf, RTC_RV3029_PAGE_LEN);

	/* give the RTC some time to update */
	udelay(1000);
	return ret;
}

/* sets EERE-Bit  (automatic EEPROM refresh) */
static void set_eere_bit(int state)
{
	unsigned char reg_ctrl1;

	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
			&reg_ctrl1, 1);

	if (state)
		reg_ctrl1 |= RTC_RV3029_CTRL1_EERE;
	else
		reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE);

	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
		&reg_ctrl1, 1);
}

/* waits until EEPROM page is no longer busy (times out after 10ms*loops) */
static int wait_eebusy(int loops)
{
	int i;
	unsigned char ctrl_status;

	for (i = 0; i < loops; i++) {
		(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS,
			1, &ctrl_status, 1);

		if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0)
			break;
		udelay(10000);
	}
	return i;
}

void rtc_reset (void)
{
	unsigned char buf[RTC_RV3029_PAGE_LEN];

	buf[0] = RTC_RV3029_CTRL_SYS_R;
	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1,
			buf, 1);

#if defined(CONFIG_SYS_RV3029_TCR)
	/*
	 * because EEPROM_CTRL register is in EEPROM page it is necessary to
	 * disable automatic EEPROM refresh and check if EEPROM is busy
	 * before EEPORM_CTRL register may be accessed
	 */
	set_eere_bit(0);
	wait_eebusy(100);
	/* read current trickle charger setting */
	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL,
			1, buf, 1);
	/* enable automatic EEPROM refresh again */
	set_eere_bit(1);

	/*
	 * to minimize EEPROM access write trickle charger setting only if it
	 * differs from current value
	 */
	if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) {
		buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR;
		/*
		 * write trickle charger setting (disable autom. EEPROM
		 * refresh and wait until EEPROM is idle)
		 */
		set_eere_bit(0);
		wait_eebusy(100);
		(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR,
				RTC_RV3029_EEPROM_CTRL, 1, buf, 1);
		/*
		 * it is necessary to wait 10ms before EEBUSY-Bit may be read
		 * (this is not documented in the data sheet yet, but the
		 * manufacturer recommends it)
		 */
		udelay(10000);
		/* wait until EEPROM write access is finished */
		wait_eebusy(100);
		set_eere_bit(1);
	}
#endif
}