percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit
[zen-stable.git] / drivers / rtc / rtc-ds1672.c
bloba319402a54479bd633a0bfdbb4710996316b1839
1 /*
2 * An rtc/i2c driver for the Dallas DS1672
3 * Copyright 2005-06 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
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.
12 #include <linux/i2c.h>
13 #include <linux/rtc.h>
14 #include <linux/module.h>
16 #define DRV_VERSION "0.4"
18 /* Registers */
20 #define DS1672_REG_CNT_BASE 0
21 #define DS1672_REG_CONTROL 4
22 #define DS1672_REG_TRICKLE 5
24 #define DS1672_REG_CONTROL_EOSC 0x80
26 static struct i2c_driver ds1672_driver;
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.
33 static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
35 unsigned long time;
36 unsigned char addr = DS1672_REG_CNT_BASE;
37 unsigned char buf[4];
39 struct i2c_msg msgs[] = {
40 {client->addr, 0, 1, &addr}, /* setup read ptr */
41 {client->addr, I2C_M_RD, 4, buf}, /* read date */
44 /* read date registers */
45 if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
46 dev_err(&client->dev, "%s: read error\n", __func__);
47 return -EIO;
50 dev_dbg(&client->dev,
51 "%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
52 __func__, buf[0], buf[1], buf[2], buf[3]);
54 time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
56 rtc_time_to_tm(time, tm);
58 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
59 "mday=%d, mon=%d, year=%d, wday=%d\n",
60 __func__, tm->tm_sec, tm->tm_min, tm->tm_hour,
61 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
63 return 0;
66 static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
68 int xfer;
69 unsigned char buf[6];
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;
76 buf[5] = 0; /* set control reg to enable counting */
78 xfer = i2c_master_send(client, buf, 6);
79 if (xfer != 6) {
80 dev_err(&client->dev, "%s: send: %d\n", __func__, xfer);
81 return -EIO;
84 return 0;
87 static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
89 return ds1672_get_datetime(to_i2c_client(dev), tm);
92 static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
94 return ds1672_set_mmss(to_i2c_client(dev), secs);
97 static int ds1672_get_control(struct i2c_client *client, u8 *status)
99 unsigned char addr = DS1672_REG_CONTROL;
101 struct i2c_msg msgs[] = {
102 {client->addr, 0, 1, &addr}, /* setup read ptr */
103 {client->addr, I2C_M_RD, 1, status}, /* read control */
106 /* read control register */
107 if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
108 dev_err(&client->dev, "%s: read error\n", __func__);
109 return -EIO;
112 return 0;
115 /* following are the sysfs callback functions */
116 static ssize_t show_control(struct device *dev, struct device_attribute *attr,
117 char *buf)
119 struct i2c_client *client = to_i2c_client(dev);
120 u8 control;
121 int err;
123 err = ds1672_get_control(client, &control);
124 if (err)
125 return err;
127 return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
128 ? "disabled" : "enabled");
131 static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
133 static const struct rtc_class_ops ds1672_rtc_ops = {
134 .read_time = ds1672_rtc_read_time,
135 .set_mmss = ds1672_rtc_set_mmss,
138 static int ds1672_remove(struct i2c_client *client)
140 struct rtc_device *rtc = i2c_get_clientdata(client);
142 if (rtc)
143 rtc_device_unregister(rtc);
145 return 0;
148 static int ds1672_probe(struct i2c_client *client,
149 const struct i2c_device_id *id)
151 int err = 0;
152 u8 control;
153 struct rtc_device *rtc;
155 dev_dbg(&client->dev, "%s\n", __func__);
157 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
158 return -ENODEV;
160 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
162 rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev,
163 &ds1672_rtc_ops, THIS_MODULE);
165 if (IS_ERR(rtc))
166 return PTR_ERR(rtc);
168 i2c_set_clientdata(client, rtc);
170 /* read control register */
171 err = ds1672_get_control(client, &control);
172 if (err)
173 goto exit_devreg;
175 if (control & DS1672_REG_CONTROL_EOSC)
176 dev_warn(&client->dev, "Oscillator not enabled. "
177 "Set time to enable.\n");
179 /* Register sysfs hooks */
180 err = device_create_file(&client->dev, &dev_attr_control);
181 if (err)
182 goto exit_devreg;
184 return 0;
186 exit_devreg:
187 rtc_device_unregister(rtc);
188 return err;
191 static struct i2c_device_id ds1672_id[] = {
192 { "ds1672", 0 },
196 static struct i2c_driver ds1672_driver = {
197 .driver = {
198 .name = "rtc-ds1672",
200 .probe = &ds1672_probe,
201 .remove = &ds1672_remove,
202 .id_table = ds1672_id,
205 static int __init ds1672_init(void)
207 return i2c_add_driver(&ds1672_driver);
210 static void __exit ds1672_exit(void)
212 i2c_del_driver(&ds1672_driver);
215 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
216 MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
217 MODULE_LICENSE("GPL");
218 MODULE_VERSION(DRV_VERSION);
220 module_init(ds1672_init);
221 module_exit(ds1672_exit);