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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ae3551f9 MR |
2 | /* |
3 | * An rtc/i2c driver for the EM Microelectronic EM3027 | |
4 | * Copyright 2011 CompuLab, Ltd. | |
5 | * | |
6 | * Author: Mike Rapoport <mike@compulab.co.il> | |
7 | * | |
8 | * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it> | |
ae3551f9 MR |
9 | */ |
10 | ||
11 | #include <linux/i2c.h> | |
12 | #include <linux/rtc.h> | |
13 | #include <linux/bcd.h> | |
2113852b | 14 | #include <linux/module.h> |
e706974d | 15 | #include <linux/of.h> |
ae3551f9 MR |
16 | |
17 | /* Registers */ | |
18 | #define EM3027_REG_ON_OFF_CTRL 0x00 | |
19 | #define EM3027_REG_IRQ_CTRL 0x01 | |
20 | #define EM3027_REG_IRQ_FLAGS 0x02 | |
21 | #define EM3027_REG_STATUS 0x03 | |
22 | #define EM3027_REG_RST_CTRL 0x04 | |
23 | ||
24 | #define EM3027_REG_WATCH_SEC 0x08 | |
25 | #define EM3027_REG_WATCH_MIN 0x09 | |
26 | #define EM3027_REG_WATCH_HOUR 0x0a | |
27 | #define EM3027_REG_WATCH_DATE 0x0b | |
28 | #define EM3027_REG_WATCH_DAY 0x0c | |
29 | #define EM3027_REG_WATCH_MON 0x0d | |
30 | #define EM3027_REG_WATCH_YEAR 0x0e | |
31 | ||
32 | #define EM3027_REG_ALARM_SEC 0x10 | |
33 | #define EM3027_REG_ALARM_MIN 0x11 | |
34 | #define EM3027_REG_ALARM_HOUR 0x12 | |
35 | #define EM3027_REG_ALARM_DATE 0x13 | |
36 | #define EM3027_REG_ALARM_DAY 0x14 | |
37 | #define EM3027_REG_ALARM_MON 0x15 | |
38 | #define EM3027_REG_ALARM_YEAR 0x16 | |
39 | ||
40 | static struct i2c_driver em3027_driver; | |
41 | ||
42 | static int em3027_get_time(struct device *dev, struct rtc_time *tm) | |
43 | { | |
44 | struct i2c_client *client = to_i2c_client(dev); | |
45 | ||
46 | unsigned char addr = EM3027_REG_WATCH_SEC; | |
47 | unsigned char buf[7]; | |
48 | ||
49 | struct i2c_msg msgs[] = { | |
84cab86c S |
50 | {/* setup read addr */ |
51 | .addr = client->addr, | |
52 | .len = 1, | |
53 | .buf = &addr | |
54 | }, | |
55 | {/* read time/date */ | |
56 | .addr = client->addr, | |
57 | .flags = I2C_M_RD, | |
58 | .len = 7, | |
59 | .buf = buf | |
60 | }, | |
ae3551f9 MR |
61 | }; |
62 | ||
63 | /* read time/date registers */ | |
64 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
65 | dev_err(&client->dev, "%s: read error\n", __func__); | |
66 | return -EIO; | |
67 | } | |
68 | ||
69 | tm->tm_sec = bcd2bin(buf[0]); | |
70 | tm->tm_min = bcd2bin(buf[1]); | |
71 | tm->tm_hour = bcd2bin(buf[2]); | |
72 | tm->tm_mday = bcd2bin(buf[3]); | |
73 | tm->tm_wday = bcd2bin(buf[4]); | |
74 | tm->tm_mon = bcd2bin(buf[5]); | |
75 | tm->tm_year = bcd2bin(buf[6]) + 100; | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static int em3027_set_time(struct device *dev, struct rtc_time *tm) | |
81 | { | |
82 | struct i2c_client *client = to_i2c_client(dev); | |
83 | unsigned char buf[8]; | |
84 | ||
85 | struct i2c_msg msg = { | |
84cab86c S |
86 | .addr = client->addr, |
87 | .len = 8, | |
88 | .buf = buf, /* write time/date */ | |
ae3551f9 MR |
89 | }; |
90 | ||
91 | buf[0] = EM3027_REG_WATCH_SEC; | |
92 | buf[1] = bin2bcd(tm->tm_sec); | |
93 | buf[2] = bin2bcd(tm->tm_min); | |
94 | buf[3] = bin2bcd(tm->tm_hour); | |
95 | buf[4] = bin2bcd(tm->tm_mday); | |
96 | buf[5] = bin2bcd(tm->tm_wday); | |
97 | buf[6] = bin2bcd(tm->tm_mon); | |
98 | buf[7] = bin2bcd(tm->tm_year % 100); | |
99 | ||
100 | /* write time/date registers */ | |
101 | if ((i2c_transfer(client->adapter, &msg, 1)) != 1) { | |
102 | dev_err(&client->dev, "%s: write error\n", __func__); | |
103 | return -EIO; | |
104 | } | |
105 | ||
106 | return 0; | |
107 | } | |
108 | ||
109 | static const struct rtc_class_ops em3027_rtc_ops = { | |
110 | .read_time = em3027_get_time, | |
111 | .set_time = em3027_set_time, | |
112 | }; | |
113 | ||
114 | static int em3027_probe(struct i2c_client *client, | |
115 | const struct i2c_device_id *id) | |
116 | { | |
117 | struct rtc_device *rtc; | |
118 | ||
119 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
120 | return -ENODEV; | |
121 | ||
019b21d0 | 122 | rtc = devm_rtc_device_register(&client->dev, em3027_driver.driver.name, |
ae3551f9 MR |
123 | &em3027_rtc_ops, THIS_MODULE); |
124 | if (IS_ERR(rtc)) | |
125 | return PTR_ERR(rtc); | |
126 | ||
127 | i2c_set_clientdata(client, rtc); | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
45a63518 | 132 | static const struct i2c_device_id em3027_id[] = { |
ae3551f9 MR |
133 | { "em3027", 0 }, |
134 | { } | |
135 | }; | |
e706974d PR |
136 | MODULE_DEVICE_TABLE(i2c, em3027_id); |
137 | ||
138 | #ifdef CONFIG_OF | |
139 | static const struct of_device_id em3027_of_match[] = { | |
140 | { .compatible = "emmicro,em3027", }, | |
141 | {} | |
142 | }; | |
143 | MODULE_DEVICE_TABLE(of, em3027_of_match); | |
144 | #endif | |
ae3551f9 MR |
145 | |
146 | static struct i2c_driver em3027_driver = { | |
147 | .driver = { | |
148 | .name = "rtc-em3027", | |
e706974d | 149 | .of_match_table = of_match_ptr(em3027_of_match), |
ae3551f9 MR |
150 | }, |
151 | .probe = &em3027_probe, | |
ae3551f9 MR |
152 | .id_table = em3027_id, |
153 | }; | |
154 | ||
0abc9201 | 155 | module_i2c_driver(em3027_driver); |
ae3551f9 MR |
156 | |
157 | MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); | |
158 | MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver"); | |
159 | MODULE_LICENSE("GPL"); |