ARM: tegra30: pm: flush L1 data before exit coherency on secondary CPU
[linux-2.6.git] / drivers / rtc / rtc-em3027.c
1 /*
2  * An rtc/i2c driver for the EM Microelectronic EM3027
3  * Copyright 2011 CompuLab, Ltd.
4  *
5  * Author: Mike Rapoport <mike@compulab.co.il>
6  *
7  * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 #include <linux/i2c.h>
15 #include <linux/rtc.h>
16 #include <linux/bcd.h>
17
18 /* Registers */
19 #define EM3027_REG_ON_OFF_CTRL  0x00
20 #define EM3027_REG_IRQ_CTRL     0x01
21 #define EM3027_REG_IRQ_FLAGS    0x02
22 #define EM3027_REG_STATUS       0x03
23 #define EM3027_REG_RST_CTRL     0x04
24
25 #define EM3027_REG_WATCH_SEC    0x08
26 #define EM3027_REG_WATCH_MIN    0x09
27 #define EM3027_REG_WATCH_HOUR   0x0a
28 #define EM3027_REG_WATCH_DATE   0x0b
29 #define EM3027_REG_WATCH_DAY    0x0c
30 #define EM3027_REG_WATCH_MON    0x0d
31 #define EM3027_REG_WATCH_YEAR   0x0e
32
33 #define EM3027_REG_ALARM_SEC    0x10
34 #define EM3027_REG_ALARM_MIN    0x11
35 #define EM3027_REG_ALARM_HOUR   0x12
36 #define EM3027_REG_ALARM_DATE   0x13
37 #define EM3027_REG_ALARM_DAY    0x14
38 #define EM3027_REG_ALARM_MON    0x15
39 #define EM3027_REG_ALARM_YEAR   0x16
40
41 static struct i2c_driver em3027_driver;
42
43 static int em3027_get_time(struct device *dev, struct rtc_time *tm)
44 {
45         struct i2c_client *client = to_i2c_client(dev);
46
47         unsigned char addr = EM3027_REG_WATCH_SEC;
48         unsigned char buf[7];
49
50         struct i2c_msg msgs[] = {
51                 {client->addr, 0, 1, &addr},            /* setup read addr */
52                 {client->addr, I2C_M_RD, 7, buf},       /* read time/date */
53         };
54
55         /* read time/date registers */
56         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
57                 dev_err(&client->dev, "%s: read error\n", __func__);
58                 return -EIO;
59         }
60
61         tm->tm_sec      = bcd2bin(buf[0]);
62         tm->tm_min      = bcd2bin(buf[1]);
63         tm->tm_hour     = bcd2bin(buf[2]);
64         tm->tm_mday     = bcd2bin(buf[3]);
65         tm->tm_wday     = bcd2bin(buf[4]);
66         tm->tm_mon      = bcd2bin(buf[5]);
67         tm->tm_year     = bcd2bin(buf[6]) + 100;
68
69         return 0;
70 }
71
72 static int em3027_set_time(struct device *dev, struct rtc_time *tm)
73 {
74         struct i2c_client *client = to_i2c_client(dev);
75         unsigned char buf[8];
76
77         struct i2c_msg msg = {
78                 client->addr, 0, 8, buf,        /* write time/date */
79         };
80
81         buf[0] = EM3027_REG_WATCH_SEC;
82         buf[1] = bin2bcd(tm->tm_sec);
83         buf[2] = bin2bcd(tm->tm_min);
84         buf[3] = bin2bcd(tm->tm_hour);
85         buf[4] = bin2bcd(tm->tm_mday);
86         buf[5] = bin2bcd(tm->tm_wday);
87         buf[6] = bin2bcd(tm->tm_mon);
88         buf[7] = bin2bcd(tm->tm_year % 100);
89
90         /* write time/date registers */
91         if ((i2c_transfer(client->adapter, &msg, 1)) != 1) {
92                 dev_err(&client->dev, "%s: write error\n", __func__);
93                 return -EIO;
94         }
95
96         return 0;
97 }
98
99 static const struct rtc_class_ops em3027_rtc_ops = {
100         .read_time = em3027_get_time,
101         .set_time = em3027_set_time,
102 };
103
104 static int em3027_probe(struct i2c_client *client,
105                         const struct i2c_device_id *id)
106 {
107         struct rtc_device *rtc;
108
109         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
110                 return -ENODEV;
111
112         rtc = rtc_device_register(em3027_driver.driver.name, &client->dev,
113                                   &em3027_rtc_ops, THIS_MODULE);
114         if (IS_ERR(rtc))
115                 return PTR_ERR(rtc);
116
117         i2c_set_clientdata(client, rtc);
118
119         return 0;
120 }
121
122 static int em3027_remove(struct i2c_client *client)
123 {
124         struct rtc_device *rtc = i2c_get_clientdata(client);
125
126         if (rtc)
127                 rtc_device_unregister(rtc);
128
129         return 0;
130 }
131
132 static struct i2c_device_id em3027_id[] = {
133         { "em3027", 0 },
134         { }
135 };
136
137 static struct i2c_driver em3027_driver = {
138         .driver = {
139                    .name = "rtc-em3027",
140         },
141         .probe = &em3027_probe,
142         .remove = &em3027_remove,
143         .id_table = em3027_id,
144 };
145
146 static int __init em3027_init(void)
147 {
148         return i2c_add_driver(&em3027_driver);
149 }
150
151 static void __exit em3027_exit(void)
152 {
153         i2c_del_driver(&em3027_driver);
154 }
155
156 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
157 MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");
158 MODULE_LICENSE("GPL");
159
160 module_init(em3027_init);
161 module_exit(em3027_exit);