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edf1aaa3 AZ |
1 | /* |
2 | * An rtc/i2c driver for the Dallas DS1672 | |
3903586a AZ |
3 | * Copyright 2005-06 Tower Technologies |
4 | * | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
edf1aaa3 AZ |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
edf1aaa3 AZ |
12 | #include <linux/i2c.h> |
13 | #include <linux/rtc.h> | |
2113852b | 14 | #include <linux/module.h> |
edf1aaa3 | 15 | |
1716b0fe | 16 | #define DRV_VERSION "0.4" |
edf1aaa3 AZ |
17 | |
18 | /* Registers */ | |
19 | ||
20 | #define DS1672_REG_CNT_BASE 0 | |
21 | #define DS1672_REG_CONTROL 4 | |
22 | #define DS1672_REG_TRICKLE 5 | |
23 | ||
3903586a | 24 | #define DS1672_REG_CONTROL_EOSC 0x80 |
edf1aaa3 | 25 | |
1716b0fe | 26 | static struct i2c_driver ds1672_driver; |
edf1aaa3 AZ |
27 | |
28 | /* | |
29 | * In the routines that deal directly with the ds1672 hardware, we use | |
30 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch | |
31 | * Epoch is initialized as 2000. Time is set to UTC. | |
32 | */ | |
33 | static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) | |
34 | { | |
35 | unsigned long time; | |
36 | unsigned char addr = DS1672_REG_CNT_BASE; | |
37 | unsigned char buf[4]; | |
38 | ||
39 | struct i2c_msg msgs[] = { | |
2bfc37df S |
40 | {/* setup read ptr */ |
41 | .addr = client->addr, | |
42 | .len = 1, | |
43 | .buf = &addr | |
44 | }, | |
45 | {/* read date */ | |
46 | .addr = client->addr, | |
47 | .flags = I2C_M_RD, | |
48 | .len = 4, | |
49 | .buf = buf | |
50 | }, | |
edf1aaa3 AZ |
51 | }; |
52 | ||
53 | /* read date registers */ | |
54 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 55 | dev_err(&client->dev, "%s: read error\n", __func__); |
edf1aaa3 AZ |
56 | return -EIO; |
57 | } | |
58 | ||
59 | dev_dbg(&client->dev, | |
11966adc | 60 | "%s: raw read data - counters=%02x,%02x,%02x,%02x\n", |
2a4e2b87 | 61 | __func__, buf[0], buf[1], buf[2], buf[3]); |
edf1aaa3 AZ |
62 | |
63 | time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; | |
64 | ||
65 | rtc_time_to_tm(time, tm); | |
66 | ||
67 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
68 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 69 | __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, |
edf1aaa3 AZ |
70 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
75 | static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) | |
76 | { | |
77 | int xfer; | |
8a95b252 | 78 | unsigned char buf[6]; |
edf1aaa3 AZ |
79 | |
80 | buf[0] = DS1672_REG_CNT_BASE; | |
81 | buf[1] = secs & 0x000000FF; | |
82 | buf[2] = (secs & 0x0000FF00) >> 8; | |
83 | buf[3] = (secs & 0x00FF0000) >> 16; | |
84 | buf[4] = (secs & 0xFF000000) >> 24; | |
1716b0fe | 85 | buf[5] = 0; /* set control reg to enable counting */ |
edf1aaa3 | 86 | |
8a95b252 KG |
87 | xfer = i2c_master_send(client, buf, 6); |
88 | if (xfer != 6) { | |
2a4e2b87 | 89 | dev_err(&client->dev, "%s: send: %d\n", __func__, xfer); |
edf1aaa3 AZ |
90 | return -EIO; |
91 | } | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
edf1aaa3 AZ |
96 | static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) |
97 | { | |
98 | return ds1672_get_datetime(to_i2c_client(dev), tm); | |
99 | } | |
100 | ||
edf1aaa3 AZ |
101 | static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) |
102 | { | |
103 | return ds1672_set_mmss(to_i2c_client(dev), secs); | |
104 | } | |
105 | ||
8a95b252 KG |
106 | static int ds1672_get_control(struct i2c_client *client, u8 *status) |
107 | { | |
108 | unsigned char addr = DS1672_REG_CONTROL; | |
109 | ||
110 | struct i2c_msg msgs[] = { | |
2bfc37df S |
111 | {/* setup read ptr */ |
112 | .addr = client->addr, | |
113 | .len = 1, | |
114 | .buf = &addr | |
115 | }, | |
116 | {/* read control */ | |
117 | .addr = client->addr, | |
118 | .flags = I2C_M_RD, | |
119 | .len = 1, | |
120 | .buf = status | |
121 | }, | |
8a95b252 KG |
122 | }; |
123 | ||
124 | /* read control register */ | |
125 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 126 | dev_err(&client->dev, "%s: read error\n", __func__); |
8a95b252 KG |
127 | return -EIO; |
128 | } | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | /* following are the sysfs callback functions */ | |
1716b0fe AZ |
134 | static ssize_t show_control(struct device *dev, struct device_attribute *attr, |
135 | char *buf) | |
8a95b252 KG |
136 | { |
137 | struct i2c_client *client = to_i2c_client(dev); | |
8a95b252 KG |
138 | u8 control; |
139 | int err; | |
140 | ||
141 | err = ds1672_get_control(client, &control); | |
142 | if (err) | |
143 | return err; | |
144 | ||
3903586a | 145 | return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) |
1716b0fe | 146 | ? "disabled" : "enabled"); |
8a95b252 | 147 | } |
1716b0fe | 148 | |
8a95b252 KG |
149 | static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); |
150 | ||
ff8371ac | 151 | static const struct rtc_class_ops ds1672_rtc_ops = { |
1716b0fe | 152 | .read_time = ds1672_rtc_read_time, |
1716b0fe | 153 | .set_mmss = ds1672_rtc_set_mmss, |
edf1aaa3 AZ |
154 | }; |
155 | ||
1716b0fe AZ |
156 | static int ds1672_probe(struct i2c_client *client, |
157 | const struct i2c_device_id *id) | |
edf1aaa3 AZ |
158 | { |
159 | int err = 0; | |
8a95b252 | 160 | u8 control; |
edf1aaa3 AZ |
161 | struct rtc_device *rtc; |
162 | ||
1716b0fe | 163 | dev_dbg(&client->dev, "%s\n", __func__); |
edf1aaa3 | 164 | |
1716b0fe AZ |
165 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
166 | return -ENODEV; | |
edf1aaa3 AZ |
167 | |
168 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
169 | ||
aac8703c | 170 | rtc = devm_rtc_device_register(&client->dev, ds1672_driver.driver.name, |
1716b0fe | 171 | &ds1672_rtc_ops, THIS_MODULE); |
edf1aaa3 | 172 | |
1716b0fe AZ |
173 | if (IS_ERR(rtc)) |
174 | return PTR_ERR(rtc); | |
edf1aaa3 AZ |
175 | |
176 | i2c_set_clientdata(client, rtc); | |
177 | ||
8a95b252 KG |
178 | /* read control register */ |
179 | err = ds1672_get_control(client, &control); | |
4071ea25 AZ |
180 | if (err) { |
181 | dev_warn(&client->dev, "Unable to read the control register\n"); | |
182 | } | |
8a95b252 KG |
183 | |
184 | if (control & DS1672_REG_CONTROL_EOSC) | |
185 | dev_warn(&client->dev, "Oscillator not enabled. " | |
1716b0fe | 186 | "Set time to enable.\n"); |
8a95b252 KG |
187 | |
188 | /* Register sysfs hooks */ | |
91046a8a JG |
189 | err = device_create_file(&client->dev, &dev_attr_control); |
190 | if (err) | |
4071ea25 AZ |
191 | dev_err(&client->dev, "Unable to create sysfs entry: %s\n", |
192 | dev_attr_control.attr.name); | |
8a95b252 | 193 | |
edf1aaa3 | 194 | return 0; |
edf1aaa3 AZ |
195 | } |
196 | ||
fe102c71 AZ |
197 | static struct i2c_device_id ds1672_id[] = { |
198 | { "ds1672", 0 }, | |
199 | { } | |
200 | }; | |
201 | ||
1716b0fe AZ |
202 | static struct i2c_driver ds1672_driver = { |
203 | .driver = { | |
204 | .name = "rtc-ds1672", | |
205 | }, | |
206 | .probe = &ds1672_probe, | |
fe102c71 | 207 | .id_table = ds1672_id, |
1716b0fe AZ |
208 | }; |
209 | ||
0abc9201 | 210 | module_i2c_driver(ds1672_driver); |
edf1aaa3 AZ |
211 | |
212 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
213 | MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); | |
214 | MODULE_LICENSE("GPL"); | |
215 | MODULE_VERSION(DRV_VERSION); |