xref: /openbmc/u-boot/drivers/rtc/rv3029.c (revision ef64e782)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2010
4  * Heiko Schocher, DENX Software Engineering, hs@denx.de
5  */
6 #include <common.h>
7 #include <command.h>
8 #include <i2c.h>
9 #include <rtc.h>
10 
11 #define RTC_RV3029_CTRL1	0x00
12 #define RTC_RV3029_CTRL1_EERE	(1 << 3)
13 
14 #define RTC_RV3029_CTRL_STATUS	0x03
15 #define RTC_RV3029_CTRLS_EEBUSY	(1 << 7)
16 
17 #define RTC_RV3029_CTRL_RESET	0x04
18 #define RTC_RV3029_CTRL_SYS_R	(1 << 4)
19 
20 #define RTC_RV3029_CLOCK_PAGE	0x08
21 #define RTC_RV3029_PAGE_LEN	7
22 
23 #define RV3029C2_W_SECONDS	0x00
24 #define RV3029C2_W_MINUTES	0x01
25 #define RV3029C2_W_HOURS	0x02
26 #define RV3029C2_W_DATE		0x03
27 #define RV3029C2_W_DAYS		0x04
28 #define RV3029C2_W_MONTHS	0x05
29 #define RV3029C2_W_YEARS	0x06
30 
31 #define RV3029C2_REG_HR_12_24          (1 << 6)  /* 24h/12h mode */
32 #define RV3029C2_REG_HR_PM             (1 << 5)  /* PM/AM bit in 12h mode */
33 
34 #define RTC_RV3029_EEPROM_CTRL	0x30
35 #define RTC_RV3029_TRICKLE_1K	(1 << 4)
36 #define RTC_RV3029_TRICKLE_5K	(1 << 5)
37 #define RTC_RV3029_TRICKLE_20K	(1 << 6)
38 #define RTC_RV3029_TRICKLE_80K	(1 << 7)
39 
40 int rtc_get( struct rtc_time *tmp )
41 {
42 	int	ret;
43 	unsigned char buf[RTC_RV3029_PAGE_LEN];
44 
45 	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1, buf, \
46 			RTC_RV3029_PAGE_LEN);
47 	if (ret) {
48 		printf("%s: error reading RTC: %x\n", __func__, ret);
49 		return -1;
50 	}
51 	tmp->tm_sec  = bcd2bin( buf[RV3029C2_W_SECONDS] & 0x7f);
52 	tmp->tm_min  = bcd2bin( buf[RV3029C2_W_MINUTES] & 0x7f);
53 	if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_12_24) {
54 		/* 12h format */
55 		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x1f);
56 		if (buf[RV3029C2_W_HOURS] & RV3029C2_REG_HR_PM)
57 			/* PM flag set */
58 			tmp->tm_hour += 12;
59 	} else
60 		tmp->tm_hour = bcd2bin(buf[RV3029C2_W_HOURS] & 0x3f);
61 
62 	tmp->tm_mday = bcd2bin( buf[RV3029C2_W_DATE] & 0x3F );
63 	tmp->tm_mon  = bcd2bin( buf[RV3029C2_W_MONTHS] & 0x1F );
64 	tmp->tm_wday = bcd2bin( buf[RV3029C2_W_DAYS] & 0x07 );
65 	/* RTC supports only years > 1999 */
66 	tmp->tm_year = bcd2bin( buf[RV3029C2_W_YEARS]) + 2000;
67 	tmp->tm_yday = 0;
68 	tmp->tm_isdst = 0;
69 
70 	debug( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
71 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
72 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
73 
74 	return 0;
75 }
76 
77 int rtc_set( struct rtc_time *tmp )
78 {
79 	int	ret;
80 	unsigned char buf[RTC_RV3029_PAGE_LEN];
81 
82 	debug( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
83 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
84 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
85 
86 	if (tmp->tm_year < 2000) {
87 		printf("RTC: year %d < 2000 not possible\n", tmp->tm_year);
88 		return -1;
89 	}
90 	buf[RV3029C2_W_SECONDS] = bin2bcd(tmp->tm_sec);
91 	buf[RV3029C2_W_MINUTES] = bin2bcd(tmp->tm_min);
92 	buf[RV3029C2_W_HOURS] = bin2bcd(tmp->tm_hour);
93 	/* set 24h format */
94 	buf[RV3029C2_W_HOURS] &= ~RV3029C2_REG_HR_12_24;
95 	buf[RV3029C2_W_DATE] = bin2bcd(tmp->tm_mday);
96 	buf[RV3029C2_W_DAYS] = bin2bcd(tmp->tm_wday);
97 	buf[RV3029C2_W_MONTHS] = bin2bcd(tmp->tm_mon);
98 	tmp->tm_year -= 2000;
99 	buf[RV3029C2_W_YEARS] = bin2bcd(tmp->tm_year);
100 	ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CLOCK_PAGE, 1,
101 			buf, RTC_RV3029_PAGE_LEN);
102 
103 	/* give the RTC some time to update */
104 	udelay(1000);
105 	return ret;
106 }
107 
108 /* sets EERE-Bit  (automatic EEPROM refresh) */
109 static void set_eere_bit(int state)
110 {
111 	unsigned char reg_ctrl1;
112 
113 	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
114 			&reg_ctrl1, 1);
115 
116 	if (state)
117 		reg_ctrl1 |= RTC_RV3029_CTRL1_EERE;
118 	else
119 		reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE);
120 
121 	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
122 		&reg_ctrl1, 1);
123 }
124 
125 /* waits until EEPROM page is no longer busy (times out after 10ms*loops) */
126 static int wait_eebusy(int loops)
127 {
128 	int i;
129 	unsigned char ctrl_status;
130 
131 	for (i = 0; i < loops; i++) {
132 		(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS,
133 			1, &ctrl_status, 1);
134 
135 		if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0)
136 			break;
137 		udelay(10000);
138 	}
139 	return i;
140 }
141 
142 void rtc_reset (void)
143 {
144 	unsigned char buf[RTC_RV3029_PAGE_LEN];
145 
146 	buf[0] = RTC_RV3029_CTRL_SYS_R;
147 	(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1,
148 			buf, 1);
149 
150 #if defined(CONFIG_SYS_RV3029_TCR)
151 	/*
152 	 * because EEPROM_CTRL register is in EEPROM page it is necessary to
153 	 * disable automatic EEPROM refresh and check if EEPROM is busy
154 	 * before EEPORM_CTRL register may be accessed
155 	 */
156 	set_eere_bit(0);
157 	wait_eebusy(100);
158 	/* read current trickle charger setting */
159 	(void)i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL,
160 			1, buf, 1);
161 	/* enable automatic EEPROM refresh again */
162 	set_eere_bit(1);
163 
164 	/*
165 	 * to minimize EEPROM access write trickle charger setting only if it
166 	 * differs from current value
167 	 */
168 	if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) {
169 		buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR;
170 		/*
171 		 * write trickle charger setting (disable autom. EEPROM
172 		 * refresh and wait until EEPROM is idle)
173 		 */
174 		set_eere_bit(0);
175 		wait_eebusy(100);
176 		(void)i2c_write(CONFIG_SYS_I2C_RTC_ADDR,
177 				RTC_RV3029_EEPROM_CTRL, 1, buf, 1);
178 		/*
179 		 * it is necessary to wait 10ms before EEBUSY-Bit may be read
180 		 * (this is not documented in the data sheet yet, but the
181 		 * manufacturer recommends it)
182 		 */
183 		udelay(10000);
184 		/* wait until EEPROM write access is finished */
185 		wait_eebusy(100);
186 		set_eere_bit(1);
187 	}
188 #endif
189 }
190