media: tegra: add supporting for RAW8/RAW10 input and output
[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/i2c.h>
13 #include <linux/rtc.h>
14
15 #define DRV_VERSION "0.4"
16
17 /* Registers */
18
19 #define DS1672_REG_CNT_BASE     0
20 #define DS1672_REG_CONTROL      4
21 #define DS1672_REG_TRICKLE      5
22
23 #define DS1672_REG_CONTROL_EOSC 0x80
24
25 static struct i2c_driver ds1672_driver;
26
27 /*
28  * In the routines that deal directly with the ds1672 hardware, we use
29  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
30  * Epoch is initialized as 2000. Time is set to UTC.
31  */
32 static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
33 {
34         unsigned long time;
35         unsigned char addr = DS1672_REG_CNT_BASE;
36         unsigned char buf[4];
37
38         struct i2c_msg msgs[] = {
39                 {client->addr, 0, 1, &addr},    /* setup read ptr */
40                 {client->addr, I2C_M_RD, 4, buf},       /* read date */
41         };
42
43         /* read date registers */
44         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
45                 dev_err(&client->dev, "%s: read error\n", __func__);
46                 return -EIO;
47         }
48
49         dev_dbg(&client->dev,
50                 "%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
51                 __func__, buf[0], buf[1], buf[2], buf[3]);
52
53         time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
54
55         rtc_time_to_tm(time, tm);
56
57         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
58                 "mday=%d, mon=%d, year=%d, wday=%d\n",
59                 __func__, tm->tm_sec, tm->tm_min, tm->tm_hour,
60                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
61
62         return 0;
63 }
64
65 static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
66 {
67         int xfer;
68         unsigned char buf[6];
69
70         buf[0] = DS1672_REG_CNT_BASE;
71         buf[1] = secs & 0x000000FF;
72         buf[2] = (secs & 0x0000FF00) >> 8;
73         buf[3] = (secs & 0x00FF0000) >> 16;
74         buf[4] = (secs & 0xFF000000) >> 24;
75         buf[5] = 0;             /* set control reg to enable counting */
76
77         xfer = i2c_master_send(client, buf, 6);
78         if (xfer != 6) {
79                 dev_err(&client->dev, "%s: send: %d\n", __func__, xfer);
80                 return -EIO;
81         }
82
83         return 0;
84 }
85
86 static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
87 {
88         return ds1672_get_datetime(to_i2c_client(dev), tm);
89 }
90
91 static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
92 {
93         return ds1672_set_mmss(to_i2c_client(dev), secs);
94 }
95
96 static int ds1672_get_control(struct i2c_client *client, u8 *status)
97 {
98         unsigned char addr = DS1672_REG_CONTROL;
99
100         struct i2c_msg msgs[] = {
101                 {client->addr, 0, 1, &addr},    /* setup read ptr */
102                 {client->addr, I2C_M_RD, 1, status},    /* read control */
103         };
104
105         /* read control register */
106         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
107                 dev_err(&client->dev, "%s: read error\n", __func__);
108                 return -EIO;
109         }
110
111         return 0;
112 }
113
114 /* following are the sysfs callback functions */
115 static ssize_t show_control(struct device *dev, struct device_attribute *attr,
116                             char *buf)
117 {
118         struct i2c_client *client = to_i2c_client(dev);
119         u8 control;
120         int err;
121
122         err = ds1672_get_control(client, &control);
123         if (err)
124                 return err;
125
126         return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
127                        ? "disabled" : "enabled");
128 }
129
130 static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
131
132 static const struct rtc_class_ops ds1672_rtc_ops = {
133         .read_time = ds1672_rtc_read_time,
134         .set_mmss = ds1672_rtc_set_mmss,
135 };
136
137 static int ds1672_remove(struct i2c_client *client)
138 {
139         struct rtc_device *rtc = i2c_get_clientdata(client);
140
141         if (rtc)
142                 rtc_device_unregister(rtc);
143
144         return 0;
145 }
146
147 static int ds1672_probe(struct i2c_client *client,
148                         const struct i2c_device_id *id)
149 {
150         int err = 0;
151         u8 control;
152         struct rtc_device *rtc;
153
154         dev_dbg(&client->dev, "%s\n", __func__);
155
156         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
157                 return -ENODEV;
158
159         dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
160
161         rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
162                                   &ds1672_rtc_ops, THIS_MODULE);
163
164         if (IS_ERR(rtc))
165                 return PTR_ERR(rtc);
166
167         i2c_set_clientdata(client, rtc);
168
169         /* read control register */
170         err = ds1672_get_control(client, &control);
171         if (err)
172                 goto exit_devreg;
173
174         if (control & DS1672_REG_CONTROL_EOSC)
175                 dev_warn(&client->dev, "Oscillator not enabled. "
176                          "Set time to enable.\n");
177
178         /* Register sysfs hooks */
179         err = device_create_file(&client->dev, &dev_attr_control);
180         if (err)
181                 goto exit_devreg;
182
183         return 0;
184
185  exit_devreg:
186         rtc_device_unregister(rtc);
187         return err;
188 }
189
190 static struct i2c_device_id ds1672_id[] = {
191         { "ds1672", 0 },
192         { }
193 };
194
195 static struct i2c_driver ds1672_driver = {
196         .driver = {
197                    .name = "rtc-ds1672",
198                    },
199         .probe = &ds1672_probe,
200         .remove = &ds1672_remove,
201         .id_table = ds1672_id,
202 };
203
204 static int __init ds1672_init(void)
205 {
206         return i2c_add_driver(&ds1672_driver);
207 }
208
209 static void __exit ds1672_exit(void)
210 {
211         i2c_del_driver(&ds1672_driver);
212 }
213
214 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
215 MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
216 MODULE_LICENSE("GPL");
217 MODULE_VERSION(DRV_VERSION);
218
219 module_init(ds1672_init);
220 module_exit(ds1672_exit);