xref: /openbmc/u-boot/drivers/rtc/pcf2127.c (revision e9c847c3)
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)  /* datetime */
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;
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 	if (dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, sizeof(buf)) < 0)
48 		return -1;
49 
50 	return 0;
51 }
52 
53 static int pcf2127_rtc_get(struct udevice *dev, struct rtc_time *tm)
54 {
55 	int rel = 0;
56 	uchar buf[10] = { PCF2127_REG_CTRL1 };
57 
58 	if (dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, 1) < 0)
59 		return -1;
60 	if (dm_i2c_read(dev, PCF2127_REG_CTRL1, buf, sizeof(buf)) < 0)
61 		return -1;
62 
63 	if (buf[PCF2127_REG_CTRL3] & 0x04)
64 		puts("### Warning: RTC Low Voltage - date/time not reliable\n");
65 
66 	tm->tm_sec  = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
67 	tm->tm_min  = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
68 	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
69 	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
70 	tm->tm_mon  = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1;
71 	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]) + 1900;
72 	if (tm->tm_year < 1970)
73 		tm->tm_year += 100;	/* assume we are in 1970...2069 */
74 	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
75 	tm->tm_yday = 0;
76 	tm->tm_isdst = 0;
77 
78 	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
79 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
80 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
81 
82 	return rel;
83 }
84 
85 static int pcf2127_rtc_reset(struct udevice *dev)
86 {
87 	/*Doing nothing here*/
88 	return 0;
89 }
90 
91 static const struct rtc_ops pcf2127_rtc_ops = {
92 	.get = pcf2127_rtc_get,
93 	.set = pcf2127_rtc_set,
94 	.reset = pcf2127_rtc_reset,
95 };
96 
97 static const struct udevice_id pcf2127_rtc_ids[] = {
98 	{ .compatible = "pcf2127-rtc" },
99 	{ }
100 };
101 
102 U_BOOT_DRIVER(rtc_pcf2127) = {
103 	.name	= "rtc-pcf2127",
104 	.id	= UCLASS_RTC,
105 	.of_match = pcf2127_rtc_ids,
106 	.ops	= &pcf2127_rtc_ops,
107 };
108