1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/*
* An rtc/i2c driver for the Dallas DS1672
* Copyright 2005-06 Tower Technologies
*
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/i2c.h>
#include <linux/rtc.h>
#define DRV_VERSION "0.4"
/* Registers */
#define DS1672_REG_CNT_BASE 0
#define DS1672_REG_CONTROL 4
#define DS1672_REG_TRICKLE 5
#define DS1672_REG_CONTROL_EOSC 0x80
static struct i2c_driver ds1672_driver;
/*
* In the routines that deal directly with the ds1672 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
* Epoch is initialized as 2000. Time is set to UTC.
*/
static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
unsigned long time;
unsigned char addr = DS1672_REG_CNT_BASE;
unsigned char buf[4];
struct i2c_msg msgs[] = {
{client->addr, 0, 1, &addr}, /* setup read ptr */
{client->addr, I2C_M_RD, 4, buf}, /* read date */
};
/* read date registers */
if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
dev_dbg(&client->dev,
"%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
__func__, buf[0], buf[1], buf[2], buf[3]);
time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
rtc_time_to_tm(time, tm);
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__, tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
return 0;
}
static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
{
int xfer;
unsigned char buf[6];
buf[0] = DS1672_REG_CNT_BASE;
buf[1] = secs & 0x000000FF;
buf[2] = (secs & 0x0000FF00) >> 8;
buf[3] = (secs & 0x00FF0000) >> 16;
buf[4] = (secs & 0xFF000000) >> 24;
buf[5] = 0; /* set control reg to enable counting */
xfer = i2c_master_send(client, buf, 6);
if (xfer != 6) {
dev_err(&client->dev, "%s: send: %d\n", __func__, xfer);
return -EIO;
}
return 0;
}
static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return ds1672_get_datetime(to_i2c_client(dev), tm);
}
static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
{
return ds1672_set_mmss(to_i2c_client(dev), secs);
}
static int ds1672_get_control(struct i2c_client *client, u8 *status)
{
unsigned char addr = DS1672_REG_CONTROL;
struct i2c_msg msgs[] = {
{client->addr, 0, 1, &addr}, /* setup read ptr */
{client->addr, I2C_M_RD, 1, status}, /* read control */
};
/* read control register */
if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
return 0;
}
/* following are the sysfs callback functions */
static ssize_t show_control(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
u8 control;
int err;
err = ds1672_get_control(client, &control);
if (err)
return err;
return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
? "disabled" : "enabled");
}
static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
static const struct rtc_class_ops ds1672_rtc_ops = {
.read_time = ds1672_rtc_read_time,
.set_mmss = ds1672_rtc_set_mmss,
};
static int ds1672_remove(struct i2c_client *client)
{
struct rtc_device *rtc = i2c_get_clientdata(client);
if (rtc)
rtc_device_unregister(rtc);
return 0;
}
static int ds1672_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err = 0;
u8 control;
struct rtc_device *rtc;
dev_dbg(&client->dev, "%s\n", __func__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
&ds1672_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
i2c_set_clientdata(client, rtc);
/* read control register */
err = ds1672_get_control(client, &control);
if (err)
goto exit_devreg;
if (control & DS1672_REG_CONTROL_EOSC)
dev_warn(&client->dev, "Oscillator not enabled. "
"Set time to enable.\n");
/* Register sysfs hooks */
err = device_create_file(&client->dev, &dev_attr_control);
if (err)
goto exit_devreg;
return 0;
exit_devreg:
rtc_device_unregister(rtc);
return err;
}
static struct i2c_device_id ds1672_id[] = {
{ "ds1672", 0 },
{ }
};
static struct i2c_driver ds1672_driver = {
.driver = {
.name = "rtc-ds1672",
},
.probe = &ds1672_probe,
.remove = &ds1672_remove,
.id_table = ds1672_id,
};
static int __init ds1672_init(void)
{
return i2c_add_driver(&ds1672_driver);
}
static void __exit ds1672_exit(void)
{
i2c_del_driver(&ds1672_driver);
}
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
module_init(ds1672_init);
module_exit(ds1672_exit);
|
