Loading...
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
25static 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 */
32static 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
65static 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
86static 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
91static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
92{
93 return ds1672_set_mmss(to_i2c_client(dev), secs);
94}
95
96static 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 */
115static 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
130static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
131
132static const struct rtc_class_ops ds1672_rtc_ops = {
133 .read_time = ds1672_rtc_read_time,
134 .set_mmss = ds1672_rtc_set_mmss,
135};
136
137static 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
147static 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
190static struct i2c_device_id ds1672_id[] = {
191 { "ds1672", 0 },
192 { }
193};
194
195static 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
204static int __init ds1672_init(void)
205{
206 return i2c_add_driver(&ds1672_driver);
207}
208
209static void __exit ds1672_exit(void)
210{
211 i2c_del_driver(&ds1672_driver);
212}
213
214MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
215MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
216MODULE_LICENSE("GPL");
217MODULE_VERSION(DRV_VERSION);
218
219module_init(ds1672_init);
220module_exit(ds1672_exit);
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#include <linux/module.h>
15
16/* Registers */
17
18#define DS1672_REG_CNT_BASE 0
19#define DS1672_REG_CONTROL 4
20#define DS1672_REG_TRICKLE 5
21
22#define DS1672_REG_CONTROL_EOSC 0x80
23
24static struct i2c_driver ds1672_driver;
25
26/*
27 * In the routines that deal directly with the ds1672 hardware, we use
28 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
29 * Epoch is initialized as 2000. Time is set to UTC.
30 */
31static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
32{
33 unsigned long time;
34 unsigned char addr = DS1672_REG_CNT_BASE;
35 unsigned char buf[4];
36
37 struct i2c_msg msgs[] = {
38 {/* setup read ptr */
39 .addr = client->addr,
40 .len = 1,
41 .buf = &addr
42 },
43 {/* read date */
44 .addr = client->addr,
45 .flags = I2C_M_RD,
46 .len = 4,
47 .buf = buf
48 },
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", __func__);
54 return -EIO;
55 }
56
57 dev_dbg(&client->dev,
58 "%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
59 __func__, 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 __func__, 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
73static 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", __func__, xfer);
88 return -EIO;
89 }
90
91 return 0;
92}
93
94static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
95{
96 return ds1672_get_datetime(to_i2c_client(dev), tm);
97}
98
99static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
100{
101 return ds1672_set_mmss(to_i2c_client(dev), secs);
102}
103
104static int ds1672_get_control(struct i2c_client *client, u8 *status)
105{
106 unsigned char addr = DS1672_REG_CONTROL;
107
108 struct i2c_msg msgs[] = {
109 {/* setup read ptr */
110 .addr = client->addr,
111 .len = 1,
112 .buf = &addr
113 },
114 {/* read control */
115 .addr = client->addr,
116 .flags = I2C_M_RD,
117 .len = 1,
118 .buf = status
119 },
120 };
121
122 /* read control register */
123 if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
124 dev_err(&client->dev, "%s: read error\n", __func__);
125 return -EIO;
126 }
127
128 return 0;
129}
130
131/* following are the sysfs callback functions */
132static ssize_t show_control(struct device *dev, struct device_attribute *attr,
133 char *buf)
134{
135 struct i2c_client *client = to_i2c_client(dev);
136 u8 control;
137 int err;
138
139 err = ds1672_get_control(client, &control);
140 if (err)
141 return err;
142
143 return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
144 ? "disabled" : "enabled");
145}
146
147static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
148
149static const struct rtc_class_ops ds1672_rtc_ops = {
150 .read_time = ds1672_rtc_read_time,
151 .set_mmss = ds1672_rtc_set_mmss,
152};
153
154static int ds1672_probe(struct i2c_client *client,
155 const struct i2c_device_id *id)
156{
157 int err = 0;
158 u8 control;
159 struct rtc_device *rtc;
160
161 dev_dbg(&client->dev, "%s\n", __func__);
162
163 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
164 return -ENODEV;
165
166 rtc = devm_rtc_device_register(&client->dev, ds1672_driver.driver.name,
167 &ds1672_rtc_ops, THIS_MODULE);
168
169 if (IS_ERR(rtc))
170 return PTR_ERR(rtc);
171
172 i2c_set_clientdata(client, rtc);
173
174 /* read control register */
175 err = ds1672_get_control(client, &control);
176 if (err) {
177 dev_warn(&client->dev, "Unable to read the control register\n");
178 }
179
180 if (control & DS1672_REG_CONTROL_EOSC)
181 dev_warn(&client->dev, "Oscillator not enabled. "
182 "Set time to enable.\n");
183
184 /* Register sysfs hooks */
185 err = device_create_file(&client->dev, &dev_attr_control);
186 if (err)
187 dev_err(&client->dev, "Unable to create sysfs entry: %s\n",
188 dev_attr_control.attr.name);
189
190 return 0;
191}
192
193static struct i2c_device_id ds1672_id[] = {
194 { "ds1672", 0 },
195 { }
196};
197MODULE_DEVICE_TABLE(i2c, ds1672_id);
198
199static struct i2c_driver ds1672_driver = {
200 .driver = {
201 .name = "rtc-ds1672",
202 },
203 .probe = &ds1672_probe,
204 .id_table = ds1672_id,
205};
206
207module_i2c_driver(ds1672_driver);
208
209MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
210MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
211MODULE_LICENSE("GPL");