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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[] = { | |
1716b0fe AZ |
40 | {client->addr, 0, 1, &addr}, /* setup read ptr */ |
41 | {client->addr, I2C_M_RD, 4, buf}, /* read date */ | |
edf1aaa3 AZ |
42 | }; |
43 | ||
44 | /* read date registers */ | |
45 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 46 | dev_err(&client->dev, "%s: read error\n", __func__); |
edf1aaa3 AZ |
47 | return -EIO; |
48 | } | |
49 | ||
50 | dev_dbg(&client->dev, | |
11966adc | 51 | "%s: raw read data - counters=%02x,%02x,%02x,%02x\n", |
2a4e2b87 | 52 | __func__, buf[0], buf[1], buf[2], buf[3]); |
edf1aaa3 AZ |
53 | |
54 | time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; | |
55 | ||
56 | rtc_time_to_tm(time, tm); | |
57 | ||
58 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
59 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 60 | __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, |
edf1aaa3 AZ |
61 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) | |
67 | { | |
68 | int xfer; | |
8a95b252 | 69 | unsigned char buf[6]; |
edf1aaa3 AZ |
70 | |
71 | buf[0] = DS1672_REG_CNT_BASE; | |
72 | buf[1] = secs & 0x000000FF; | |
73 | buf[2] = (secs & 0x0000FF00) >> 8; | |
74 | buf[3] = (secs & 0x00FF0000) >> 16; | |
75 | buf[4] = (secs & 0xFF000000) >> 24; | |
1716b0fe | 76 | buf[5] = 0; /* set control reg to enable counting */ |
edf1aaa3 | 77 | |
8a95b252 KG |
78 | xfer = i2c_master_send(client, buf, 6); |
79 | if (xfer != 6) { | |
2a4e2b87 | 80 | dev_err(&client->dev, "%s: send: %d\n", __func__, xfer); |
edf1aaa3 AZ |
81 | return -EIO; |
82 | } | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
edf1aaa3 AZ |
87 | static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) |
88 | { | |
89 | return ds1672_get_datetime(to_i2c_client(dev), tm); | |
90 | } | |
91 | ||
edf1aaa3 AZ |
92 | static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) |
93 | { | |
94 | return ds1672_set_mmss(to_i2c_client(dev), secs); | |
95 | } | |
96 | ||
8a95b252 KG |
97 | static int ds1672_get_control(struct i2c_client *client, u8 *status) |
98 | { | |
99 | unsigned char addr = DS1672_REG_CONTROL; | |
100 | ||
101 | struct i2c_msg msgs[] = { | |
1716b0fe AZ |
102 | {client->addr, 0, 1, &addr}, /* setup read ptr */ |
103 | {client->addr, I2C_M_RD, 1, status}, /* read control */ | |
8a95b252 KG |
104 | }; |
105 | ||
106 | /* read control register */ | |
107 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 108 | dev_err(&client->dev, "%s: read error\n", __func__); |
8a95b252 KG |
109 | return -EIO; |
110 | } | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | /* following are the sysfs callback functions */ | |
1716b0fe AZ |
116 | static ssize_t show_control(struct device *dev, struct device_attribute *attr, |
117 | char *buf) | |
8a95b252 KG |
118 | { |
119 | struct i2c_client *client = to_i2c_client(dev); | |
8a95b252 KG |
120 | u8 control; |
121 | int err; | |
122 | ||
123 | err = ds1672_get_control(client, &control); | |
124 | if (err) | |
125 | return err; | |
126 | ||
3903586a | 127 | return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) |
1716b0fe | 128 | ? "disabled" : "enabled"); |
8a95b252 | 129 | } |
1716b0fe | 130 | |
8a95b252 KG |
131 | static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); |
132 | ||
ff8371ac | 133 | static const struct rtc_class_ops ds1672_rtc_ops = { |
1716b0fe | 134 | .read_time = ds1672_rtc_read_time, |
1716b0fe | 135 | .set_mmss = ds1672_rtc_set_mmss, |
edf1aaa3 AZ |
136 | }; |
137 | ||
1716b0fe | 138 | static int ds1672_remove(struct i2c_client *client) |
edf1aaa3 | 139 | { |
edf1aaa3 AZ |
140 | struct rtc_device *rtc = i2c_get_clientdata(client); |
141 | ||
1716b0fe | 142 | if (rtc) |
edf1aaa3 AZ |
143 | rtc_device_unregister(rtc); |
144 | ||
edf1aaa3 AZ |
145 | return 0; |
146 | } | |
147 | ||
1716b0fe AZ |
148 | static int ds1672_probe(struct i2c_client *client, |
149 | const struct i2c_device_id *id) | |
edf1aaa3 AZ |
150 | { |
151 | int err = 0; | |
8a95b252 | 152 | u8 control; |
edf1aaa3 AZ |
153 | struct rtc_device *rtc; |
154 | ||
1716b0fe | 155 | dev_dbg(&client->dev, "%s\n", __func__); |
edf1aaa3 | 156 | |
1716b0fe AZ |
157 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
158 | return -ENODEV; | |
edf1aaa3 AZ |
159 | |
160 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); | |
161 | ||
162 | rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, | |
1716b0fe | 163 | &ds1672_rtc_ops, THIS_MODULE); |
edf1aaa3 | 164 | |
1716b0fe AZ |
165 | if (IS_ERR(rtc)) |
166 | return PTR_ERR(rtc); | |
edf1aaa3 AZ |
167 | |
168 | i2c_set_clientdata(client, rtc); | |
169 | ||
8a95b252 KG |
170 | /* read control register */ |
171 | err = ds1672_get_control(client, &control); | |
3903586a | 172 | if (err) |
91046a8a | 173 | goto exit_devreg; |
8a95b252 KG |
174 | |
175 | if (control & DS1672_REG_CONTROL_EOSC) | |
176 | dev_warn(&client->dev, "Oscillator not enabled. " | |
1716b0fe | 177 | "Set time to enable.\n"); |
8a95b252 KG |
178 | |
179 | /* Register sysfs hooks */ | |
91046a8a JG |
180 | err = device_create_file(&client->dev, &dev_attr_control); |
181 | if (err) | |
182 | goto exit_devreg; | |
8a95b252 | 183 | |
edf1aaa3 AZ |
184 | return 0; |
185 | ||
1716b0fe | 186 | exit_devreg: |
91046a8a | 187 | rtc_device_unregister(rtc); |
edf1aaa3 AZ |
188 | return err; |
189 | } | |
190 | ||
fe102c71 AZ |
191 | static struct i2c_device_id ds1672_id[] = { |
192 | { "ds1672", 0 }, | |
193 | { } | |
194 | }; | |
195 | ||
1716b0fe AZ |
196 | static struct i2c_driver ds1672_driver = { |
197 | .driver = { | |
198 | .name = "rtc-ds1672", | |
199 | }, | |
200 | .probe = &ds1672_probe, | |
201 | .remove = &ds1672_remove, | |
fe102c71 | 202 | .id_table = ds1672_id, |
1716b0fe AZ |
203 | }; |
204 | ||
0abc9201 | 205 | module_i2c_driver(ds1672_driver); |
edf1aaa3 AZ |
206 | |
207 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
208 | MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); | |
209 | MODULE_LICENSE("GPL"); | |
210 | MODULE_VERSION(DRV_VERSION); |