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
|
/*
* An rtc/i2c driver for the EM Microelectronic EM3027
* Copyright 2011 CompuLab, Ltd.
*
* Author: Mike Rapoport <mike@compulab.co.il>
*
* Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/i2c.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/module.h>
#include <linux/of.h>
/* Registers */
#define EM3027_REG_ON_OFF_CTRL 0x00
#define EM3027_REG_IRQ_CTRL 0x01
#define EM3027_REG_IRQ_FLAGS 0x02
#define EM3027_REG_STATUS 0x03
#define EM3027_REG_RST_CTRL 0x04
#define EM3027_REG_WATCH_SEC 0x08
#define EM3027_REG_WATCH_MIN 0x09
#define EM3027_REG_WATCH_HOUR 0x0a
#define EM3027_REG_WATCH_DATE 0x0b
#define EM3027_REG_WATCH_DAY 0x0c
#define EM3027_REG_WATCH_MON 0x0d
#define EM3027_REG_WATCH_YEAR 0x0e
#define EM3027_REG_ALARM_SEC 0x10
#define EM3027_REG_ALARM_MIN 0x11
#define EM3027_REG_ALARM_HOUR 0x12
#define EM3027_REG_ALARM_DATE 0x13
#define EM3027_REG_ALARM_DAY 0x14
#define EM3027_REG_ALARM_MON 0x15
#define EM3027_REG_ALARM_YEAR 0x16
static struct i2c_driver em3027_driver;
static int em3027_get_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char addr = EM3027_REG_WATCH_SEC;
unsigned char buf[7];
struct i2c_msg msgs[] = {
{/* setup read addr */
.addr = client->addr,
.len = 1,
.buf = &addr
},
{/* read time/date */
.addr = client->addr,
.flags = I2C_M_RD,
.len = 7,
.buf = buf
},
};
/* read time/date registers */
if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
tm->tm_sec = bcd2bin(buf[0]);
tm->tm_min = bcd2bin(buf[1]);
tm->tm_hour = bcd2bin(buf[2]);
tm->tm_mday = bcd2bin(buf[3]);
tm->tm_wday = bcd2bin(buf[4]);
tm->tm_mon = bcd2bin(buf[5]);
tm->tm_year = bcd2bin(buf[6]) + 100;
return 0;
}
static int em3027_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char buf[8];
struct i2c_msg msg = {
.addr = client->addr,
.len = 8,
.buf = buf, /* write time/date */
};
buf[0] = EM3027_REG_WATCH_SEC;
buf[1] = bin2bcd(tm->tm_sec);
buf[2] = bin2bcd(tm->tm_min);
buf[3] = bin2bcd(tm->tm_hour);
buf[4] = bin2bcd(tm->tm_mday);
buf[5] = bin2bcd(tm->tm_wday);
buf[6] = bin2bcd(tm->tm_mon);
buf[7] = bin2bcd(tm->tm_year % 100);
/* write time/date registers */
if ((i2c_transfer(client->adapter, &msg, 1)) != 1) {
dev_err(&client->dev, "%s: write error\n", __func__);
return -EIO;
}
return 0;
}
static const struct rtc_class_ops em3027_rtc_ops = {
.read_time = em3027_get_time,
.set_time = em3027_set_time,
};
static int em3027_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct rtc_device *rtc;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
rtc = devm_rtc_device_register(&client->dev, em3027_driver.driver.name,
&em3027_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
i2c_set_clientdata(client, rtc);
return 0;
}
static const struct i2c_device_id em3027_id[] = {
{ "em3027", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, em3027_id);
#ifdef CONFIG_OF
static const struct of_device_id em3027_of_match[] = {
{ .compatible = "emmicro,em3027", },
{}
};
MODULE_DEVICE_TABLE(of, em3027_of_match);
#endif
static struct i2c_driver em3027_driver = {
.driver = {
.name = "rtc-em3027",
.of_match_table = of_match_ptr(em3027_of_match),
},
.probe = &em3027_probe,
.id_table = em3027_id,
};
module_i2c_driver(em3027_driver);
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");
MODULE_LICENSE("GPL");
|
