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ae3551f9 MR |
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> | |
2113852b | 17 | #include <linux/module.h> |
ae3551f9 MR |
18 | |
19 | /* Registers */ | |
20 | #define EM3027_REG_ON_OFF_CTRL 0x00 | |
21 | #define EM3027_REG_IRQ_CTRL 0x01 | |
22 | #define EM3027_REG_IRQ_FLAGS 0x02 | |
23 | #define EM3027_REG_STATUS 0x03 | |
24 | #define EM3027_REG_RST_CTRL 0x04 | |
25 | ||
26 | #define EM3027_REG_WATCH_SEC 0x08 | |
27 | #define EM3027_REG_WATCH_MIN 0x09 | |
28 | #define EM3027_REG_WATCH_HOUR 0x0a | |
29 | #define EM3027_REG_WATCH_DATE 0x0b | |
30 | #define EM3027_REG_WATCH_DAY 0x0c | |
31 | #define EM3027_REG_WATCH_MON 0x0d | |
32 | #define EM3027_REG_WATCH_YEAR 0x0e | |
33 | ||
34 | #define EM3027_REG_ALARM_SEC 0x10 | |
35 | #define EM3027_REG_ALARM_MIN 0x11 | |
36 | #define EM3027_REG_ALARM_HOUR 0x12 | |
37 | #define EM3027_REG_ALARM_DATE 0x13 | |
38 | #define EM3027_REG_ALARM_DAY 0x14 | |
39 | #define EM3027_REG_ALARM_MON 0x15 | |
40 | #define EM3027_REG_ALARM_YEAR 0x16 | |
41 | ||
42 | static struct i2c_driver em3027_driver; | |
43 | ||
44 | static int em3027_get_time(struct device *dev, struct rtc_time *tm) | |
45 | { | |
46 | struct i2c_client *client = to_i2c_client(dev); | |
47 | ||
48 | unsigned char addr = EM3027_REG_WATCH_SEC; | |
49 | unsigned char buf[7]; | |
50 | ||
51 | struct i2c_msg msgs[] = { | |
84cab86c S |
52 | {/* setup read addr */ |
53 | .addr = client->addr, | |
54 | .len = 1, | |
55 | .buf = &addr | |
56 | }, | |
57 | {/* read time/date */ | |
58 | .addr = client->addr, | |
59 | .flags = I2C_M_RD, | |
60 | .len = 7, | |
61 | .buf = buf | |
62 | }, | |
ae3551f9 MR |
63 | }; |
64 | ||
65 | /* read time/date registers */ | |
66 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
67 | dev_err(&client->dev, "%s: read error\n", __func__); | |
68 | return -EIO; | |
69 | } | |
70 | ||
71 | tm->tm_sec = bcd2bin(buf[0]); | |
72 | tm->tm_min = bcd2bin(buf[1]); | |
73 | tm->tm_hour = bcd2bin(buf[2]); | |
74 | tm->tm_mday = bcd2bin(buf[3]); | |
75 | tm->tm_wday = bcd2bin(buf[4]); | |
76 | tm->tm_mon = bcd2bin(buf[5]); | |
77 | tm->tm_year = bcd2bin(buf[6]) + 100; | |
78 | ||
79 | return 0; | |
80 | } | |
81 | ||
82 | static int em3027_set_time(struct device *dev, struct rtc_time *tm) | |
83 | { | |
84 | struct i2c_client *client = to_i2c_client(dev); | |
85 | unsigned char buf[8]; | |
86 | ||
87 | struct i2c_msg msg = { | |
84cab86c S |
88 | .addr = client->addr, |
89 | .len = 8, | |
90 | .buf = buf, /* write time/date */ | |
ae3551f9 MR |
91 | }; |
92 | ||
93 | buf[0] = EM3027_REG_WATCH_SEC; | |
94 | buf[1] = bin2bcd(tm->tm_sec); | |
95 | buf[2] = bin2bcd(tm->tm_min); | |
96 | buf[3] = bin2bcd(tm->tm_hour); | |
97 | buf[4] = bin2bcd(tm->tm_mday); | |
98 | buf[5] = bin2bcd(tm->tm_wday); | |
99 | buf[6] = bin2bcd(tm->tm_mon); | |
100 | buf[7] = bin2bcd(tm->tm_year % 100); | |
101 | ||
102 | /* write time/date registers */ | |
103 | if ((i2c_transfer(client->adapter, &msg, 1)) != 1) { | |
104 | dev_err(&client->dev, "%s: write error\n", __func__); | |
105 | return -EIO; | |
106 | } | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static const struct rtc_class_ops em3027_rtc_ops = { | |
112 | .read_time = em3027_get_time, | |
113 | .set_time = em3027_set_time, | |
114 | }; | |
115 | ||
116 | static int em3027_probe(struct i2c_client *client, | |
117 | const struct i2c_device_id *id) | |
118 | { | |
119 | struct rtc_device *rtc; | |
120 | ||
121 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
122 | return -ENODEV; | |
123 | ||
124 | rtc = rtc_device_register(em3027_driver.driver.name, &client->dev, | |
125 | &em3027_rtc_ops, THIS_MODULE); | |
126 | if (IS_ERR(rtc)) | |
127 | return PTR_ERR(rtc); | |
128 | ||
129 | i2c_set_clientdata(client, rtc); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int em3027_remove(struct i2c_client *client) | |
135 | { | |
136 | struct rtc_device *rtc = i2c_get_clientdata(client); | |
137 | ||
138 | if (rtc) | |
139 | rtc_device_unregister(rtc); | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | static struct i2c_device_id em3027_id[] = { | |
145 | { "em3027", 0 }, | |
146 | { } | |
147 | }; | |
148 | ||
149 | static struct i2c_driver em3027_driver = { | |
150 | .driver = { | |
151 | .name = "rtc-em3027", | |
152 | }, | |
153 | .probe = &em3027_probe, | |
154 | .remove = &em3027_remove, | |
155 | .id_table = em3027_id, | |
156 | }; | |
157 | ||
0abc9201 | 158 | module_i2c_driver(em3027_driver); |
ae3551f9 MR |
159 | |
160 | MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); | |
161 | MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver"); | |
162 | MODULE_LICENSE("GPL"); |