rtc-m48t59 driver NO_IRQ mode fixup
[linux-2.6.git] / drivers / rtc / rtc-ds1672.c
1 /*
2  * An rtc/i2c driver for the Dallas DS1672
3  * Copyright 2005-06 Tower Technologies
4  *
5  * Author: Alessandro Zummo <a.zummo@towertech.it>
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
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15
16 #define DRV_VERSION "0.3"
17
18 /* Addresses to scan: none. This chip cannot be detected. */
19 static unsigned short normal_i2c[] = { I2C_CLIENT_END };
20
21 /* Insmod parameters */
22 I2C_CLIENT_INSMOD;
23
24 /* Registers */
25
26 #define DS1672_REG_CNT_BASE     0
27 #define DS1672_REG_CONTROL      4
28 #define DS1672_REG_TRICKLE      5
29
30 #define DS1672_REG_CONTROL_EOSC 0x80
31
32 /* Prototypes */
33 static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind);
34
35 /*
36  * In the routines that deal directly with the ds1672 hardware, we use
37  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
38  * Epoch is initialized as 2000. Time is set to UTC.
39  */
40 static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
41 {
42         unsigned long time;
43         unsigned char addr = DS1672_REG_CNT_BASE;
44         unsigned char buf[4];
45
46         struct i2c_msg msgs[] = {
47                 { client->addr, 0, 1, &addr },          /* setup read ptr */
48                 { client->addr, I2C_M_RD, 4, buf },     /* read date */
49         };
50
51         /* read date registers */
52         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
53                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
54                 return -EIO;
55         }
56
57         dev_dbg(&client->dev,
58                 "%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
59                 __FUNCTION__, buf[0], buf[1], buf[2], buf[3]);
60
61         time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
62
63         rtc_time_to_tm(time, tm);
64
65         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
66                 "mday=%d, mon=%d, year=%d, wday=%d\n",
67                 __FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
68                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
69
70         return 0;
71 }
72
73 static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
74 {
75         int xfer;
76         unsigned char buf[6];
77
78         buf[0] = DS1672_REG_CNT_BASE;
79         buf[1] = secs & 0x000000FF;
80         buf[2] = (secs & 0x0000FF00) >> 8;
81         buf[3] = (secs & 0x00FF0000) >> 16;
82         buf[4] = (secs & 0xFF000000) >> 24;
83         buf[5] = 0;     /* set control reg to enable counting */
84
85         xfer = i2c_master_send(client, buf, 6);
86         if (xfer != 6) {
87                 dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer);
88                 return -EIO;
89         }
90
91         return 0;
92 }
93
94 static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm)
95 {
96         unsigned long secs;
97
98         dev_dbg(&client->dev,
99                 "%s: secs=%d, mins=%d, hours=%d, "
100                 "mday=%d, mon=%d, year=%d, wday=%d\n",
101                 __FUNCTION__,
102                 tm->tm_sec, tm->tm_min, tm->tm_hour,
103                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
104
105         rtc_tm_to_time(tm, &secs);
106
107         return ds1672_set_mmss(client, secs);
108 }
109
110 static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
111 {
112         return ds1672_get_datetime(to_i2c_client(dev), tm);
113 }
114
115 static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm)
116 {
117         return ds1672_set_datetime(to_i2c_client(dev), tm);
118 }
119
120 static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
121 {
122         return ds1672_set_mmss(to_i2c_client(dev), secs);
123 }
124
125 static int ds1672_get_control(struct i2c_client *client, u8 *status)
126 {
127         unsigned char addr = DS1672_REG_CONTROL;
128
129         struct i2c_msg msgs[] = {
130                 { client->addr, 0, 1, &addr },          /* setup read ptr */
131                 { client->addr, I2C_M_RD, 1, status },  /* read control */
132         };
133
134         /* read control register */
135         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
136                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
137                 return -EIO;
138         }
139
140         return 0;
141 }
142
143 /* following are the sysfs callback functions */
144 static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf)
145 {
146         struct i2c_client *client = to_i2c_client(dev);
147         u8 control;
148         int err;
149
150         err = ds1672_get_control(client, &control);
151         if (err)
152                 return err;
153
154         return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
155                                         ? "disabled" : "enabled");
156 }
157 static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
158
159 static const struct rtc_class_ops ds1672_rtc_ops = {
160         .read_time      = ds1672_rtc_read_time,
161         .set_time       = ds1672_rtc_set_time,
162         .set_mmss       = ds1672_rtc_set_mmss,
163 };
164
165 static int ds1672_attach(struct i2c_adapter *adapter)
166 {
167         return i2c_probe(adapter, &addr_data, ds1672_probe);
168 }
169
170 static int ds1672_detach(struct i2c_client *client)
171 {
172         int err;
173         struct rtc_device *rtc = i2c_get_clientdata(client);
174
175         if (rtc)
176                 rtc_device_unregister(rtc);
177
178         if ((err = i2c_detach_client(client)))
179                 return err;
180
181         kfree(client);
182
183         return 0;
184 }
185
186 static struct i2c_driver ds1672_driver = {
187         .driver         = {
188                 .name   = "ds1672",
189         },
190         .id             = I2C_DRIVERID_DS1672,
191         .attach_adapter = &ds1672_attach,
192         .detach_client  = &ds1672_detach,
193 };
194
195 static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind)
196 {
197         int err = 0;
198         u8 control;
199         struct i2c_client *client;
200         struct rtc_device *rtc;
201
202         dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
203
204         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
205                 err = -ENODEV;
206                 goto exit;
207         }
208
209         if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
210                 err = -ENOMEM;
211                 goto exit;
212         }
213
214         /* I2C client */
215         client->addr = address;
216         client->driver = &ds1672_driver;
217         client->adapter = adapter;
218
219         strlcpy(client->name, ds1672_driver.driver.name, I2C_NAME_SIZE);
220
221         /* Inform the i2c layer */
222         if ((err = i2c_attach_client(client)))
223                 goto exit_kfree;
224
225         dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
226
227         rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
228                                 &ds1672_rtc_ops, THIS_MODULE);
229
230         if (IS_ERR(rtc)) {
231                 err = PTR_ERR(rtc);
232                 goto exit_detach;
233         }
234
235         i2c_set_clientdata(client, rtc);
236
237         /* read control register */
238         err = ds1672_get_control(client, &control);
239         if (err)
240                 goto exit_devreg;
241
242         if (control & DS1672_REG_CONTROL_EOSC)
243                 dev_warn(&client->dev, "Oscillator not enabled. "
244                                         "Set time to enable.\n");
245
246         /* Register sysfs hooks */
247         err = device_create_file(&client->dev, &dev_attr_control);
248         if (err)
249                 goto exit_devreg;
250
251         return 0;
252
253 exit_devreg:
254         rtc_device_unregister(rtc);
255
256 exit_detach:
257         i2c_detach_client(client);
258
259 exit_kfree:
260         kfree(client);
261
262 exit:
263         return err;
264 }
265
266 static int __init ds1672_init(void)
267 {
268         return i2c_add_driver(&ds1672_driver);
269 }
270
271 static void __exit ds1672_exit(void)
272 {
273         i2c_del_driver(&ds1672_driver);
274 }
275
276 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
277 MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
278 MODULE_LICENSE("GPL");
279 MODULE_VERSION(DRV_VERSION);
280
281 module_init(ds1672_init);
282 module_exit(ds1672_exit);