xref: /openbmc/u-boot/drivers/rtc/pcf2127.c (revision 8ee59472)
1 /*
2  * Copyright (C) 2016 by NXP Semiconductors Inc.
3  * Date & Time support for PCF2127 RTC
4  */
5 
6 /*	#define	DEBUG	*/
7 
8 #include <common.h>
9 #include <command.h>
10 #include <dm.h>
11 #include <i2c.h>
12 #include <rtc.h>
13 
14 #define PCF2127_REG_CTRL1	0x00
15 #define PCF2127_REG_CTRL2	0x01
16 #define PCF2127_REG_CTRL3	0x02
17 #define PCF2127_REG_SC		0x03
18 #define PCF2127_REG_MN		0x04
19 #define PCF2127_REG_HR		0x05
20 #define PCF2127_REG_DM		0x06
21 #define PCF2127_REG_DW		0x07
22 #define PCF2127_REG_MO		0x08
23 #define PCF2127_REG_YR		0x09
24 
25 static int pcf2127_rtc_set(struct udevice *dev, const struct rtc_time *tm)
26 {
27 	uchar buf[8];
28 	int i = 0, ret;
29 
30 	/* start register address */
31 	buf[i++] = PCF2127_REG_SC;
32 
33 	/* hours, minutes and seconds */
34 	buf[i++] = bin2bcd(tm->tm_sec);
35 	buf[i++] = bin2bcd(tm->tm_min);
36 	buf[i++] = bin2bcd(tm->tm_hour);
37 	buf[i++] = bin2bcd(tm->tm_mday);
38 	buf[i++] = tm->tm_wday & 0x07;
39 
40 	/* month, 1 - 12 */
41 	buf[i++] = bin2bcd(tm->tm_mon + 1);
42 
43 	/* year */
44 	buf[i++] = bin2bcd(tm->tm_year % 100);
45 
46 	/* write register's data */
47 	ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
48 
49 	return ret;
50 }
51 
52 static int pcf2127_rtc_get(struct udevice *dev, struct rtc_time *tm)
53 {
54 	int ret = 0;
55 	uchar buf[10] = { PCF2127_REG_CTRL1 };
56 
57 	ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, 1);
58 	if (ret < 0)
59 		return ret;
60 	ret = dm_i2c_read(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
61 	if (ret < 0)
62 		return ret;
63 
64 	if (buf[PCF2127_REG_CTRL3] & 0x04)
65 		puts("### Warning: RTC Low Voltage - date/time not reliable\n");
66 
67 	tm->tm_sec  = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
68 	tm->tm_min  = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
69 	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
70 	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
71 	tm->tm_mon  = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1;
72 	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]) + 1900;
73 	if (tm->tm_year < 1970)
74 		tm->tm_year += 100;	/* assume we are in 1970...2069 */
75 	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
76 	tm->tm_yday = 0;
77 	tm->tm_isdst = 0;
78 
79 	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
80 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
81 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
82 
83 	return ret;
84 }
85 
86 static int pcf2127_rtc_reset(struct udevice *dev)
87 {
88 	/*Doing nothing here*/
89 
90 	return 0;
91 }
92 
93 static const struct rtc_ops pcf2127_rtc_ops = {
94 	.get = pcf2127_rtc_get,
95 	.set = pcf2127_rtc_set,
96 	.reset = pcf2127_rtc_reset,
97 };
98 
99 static const struct udevice_id pcf2127_rtc_ids[] = {
100 	{ .compatible = "pcf2127-rtc" },
101 	{ }
102 };
103 
104 U_BOOT_DRIVER(rtc_pcf2127) = {
105 	.name	= "rtc-pcf2127",
106 	.id	= UCLASS_RTC,
107 	.of_match = pcf2127_rtc_ids,
108 	.ops	= &pcf2127_rtc_ops,
109 };
110