1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Date & Time support for Micro Crystal RV-8803-C7.
4 *
5 * based on ds1307.c which is
6 * (C) Copyright 2001, 2002, 2003
7 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
8 * Keith Outwater, keith_outwater@mvis.com`
9 * Steven Scholz, steven.scholz@imc-berlin.de
10 *
11 */
12
13 #include <common.h>
14 #include <command.h>
15 #include <dm.h>
16 #include <log.h>
17 #include <rtc.h>
18 #include <i2c.h>
19 #include <linux/bitops.h>
20
21 /*
22 * RTC register addresses
23 */
24 #define RTC_SEC_REG_ADDR 0x00
25 #define RTC_MIN_REG_ADDR 0x01
26 #define RTC_HR_REG_ADDR 0x02
27 #define RTC_DAY_REG_ADDR 0x03
28 #define RTC_DATE_REG_ADDR 0x04
29 #define RTC_MON_REG_ADDR 0x05
30 #define RTC_YR_REG_ADDR 0x06
31
32 #define RTC_FLAG_REG_ADDR 0x0E
33 #define RTC_FLAG_BIT_V1F BIT(0)
34 #define RTC_FLAG_BIT_V2F BIT(1)
35
36 #define RTC_CTL_REG_ADDR 0x0F
37 #define RTC_CTL_BIT_RST BIT(0)
38
rv8803_rtc_set(struct udevice * dev,const struct rtc_time * tm)39 static int rv8803_rtc_set(struct udevice *dev, const struct rtc_time *tm)
40 {
41 int ret;
42 u8 buf[7];
43
44 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
45 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
46 tm->tm_hour, tm->tm_min, tm->tm_sec);
47
48 if (tm->tm_year < 2000 || tm->tm_year > 2099)
49 printf("WARNING: year should be between 2000 and 2099!\n");
50
51 buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
52 buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
53 buf[RTC_DAY_REG_ADDR] = 1 << (tm->tm_wday & 0x7);
54 buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
55 buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
56 buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
57 buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
58
59 ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
60 if (ret < 0)
61 return ret;
62
63 return 0;
64 }
65
rv8803_rtc_get(struct udevice * dev,struct rtc_time * tm)66 static int rv8803_rtc_get(struct udevice *dev, struct rtc_time *tm)
67 {
68 int ret;
69 u8 buf[7];
70 int flags;
71
72 flags = dm_i2c_reg_read(dev, RTC_FLAG_REG_ADDR);
73 if (flags < 0)
74 return flags;
75 debug("%s: flags=%Xh\n", __func__, flags);
76
77 if (flags & RTC_FLAG_BIT_V1F)
78 printf("### Warning: temperature compensation has stopped\n");
79
80 if (flags & RTC_FLAG_BIT_V2F) {
81 printf("### Warning: Voltage low, data is invalid\n");
82 return -1;
83 }
84
85 ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
86 if (ret < 0)
87 return ret;
88
89 tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
90 tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
91 tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
92 tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
93 tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
94 tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
95 tm->tm_wday = fls(buf[RTC_DAY_REG_ADDR] & 0x7F) - 1;
96 tm->tm_yday = 0;
97 tm->tm_isdst = 0;
98
99 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
100 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
101 tm->tm_hour, tm->tm_min, tm->tm_sec);
102
103 return 0;
104 }
105
rv8803_rtc_reset(struct udevice * dev)106 static int rv8803_rtc_reset(struct udevice *dev)
107 {
108 int ret;
109 struct rtc_time tmp = {
110 .tm_year = 2000,
111 .tm_mon = 1,
112 .tm_mday = 1,
113 .tm_hour = 0,
114 .tm_min = 0,
115 .tm_sec = 0,
116 };
117
118 /* assert reset */
119 ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, RTC_CTL_BIT_RST);
120 if (ret < 0)
121 return ret;
122
123 /* clear all flags */
124 ret = dm_i2c_reg_write(dev, RTC_FLAG_REG_ADDR, 0);
125 if (ret < 0)
126 return ret;
127
128 ret = rv8803_rtc_set(dev, &tmp);
129 if (ret < 0)
130 return ret;
131
132 /* clear reset */
133 ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 0);
134 if (ret < 0)
135 return ret;
136
137 debug("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
138 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
139 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
140
141 return 0;
142 }
143
rv8803_probe(struct udevice * dev)144 static int rv8803_probe(struct udevice *dev)
145 {
146 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
147 DM_I2C_CHIP_WR_ADDRESS);
148
149 return 0;
150 }
151
152 static const struct rtc_ops rv8803_rtc_ops = {
153 .get = rv8803_rtc_get,
154 .set = rv8803_rtc_set,
155 .reset = rv8803_rtc_reset,
156 };
157
158 static const struct udevice_id rv8803_rtc_ids[] = {
159 { .compatible = "microcrystal,rv8803", },
160 { }
161 };
162
163 U_BOOT_DRIVER(rtc_rv8803) = {
164 .name = "rtc-rv8803",
165 .id = UCLASS_RTC,
166 .probe = rv8803_probe,
167 .of_match = rv8803_rtc_ids,
168 .ops = &rv8803_rtc_ops,
169 };
170