Commit | Line | Data |
---|---|---|
edf1aaa3 AZ |
1 | /* |
2 | * An rtc/i2c driver for the Dallas DS1672 | |
3903586a AZ |
3 | * Copyright 2005-06 Tower Technologies |
4 | * | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
edf1aaa3 AZ |
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 | ||
edf1aaa3 AZ |
12 | #include <linux/i2c.h> |
13 | #include <linux/rtc.h> | |
2113852b | 14 | #include <linux/module.h> |
edf1aaa3 | 15 | |
edf1aaa3 AZ |
16 | /* Registers */ |
17 | ||
18 | #define DS1672_REG_CNT_BASE 0 | |
19 | #define DS1672_REG_CONTROL 4 | |
20 | #define DS1672_REG_TRICKLE 5 | |
21 | ||
3903586a | 22 | #define DS1672_REG_CONTROL_EOSC 0x80 |
edf1aaa3 | 23 | |
1716b0fe | 24 | static struct i2c_driver ds1672_driver; |
edf1aaa3 AZ |
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 | */ | |
31 | static 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[] = { | |
2bfc37df S |
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 | }, | |
edf1aaa3 AZ |
49 | }; |
50 | ||
51 | /* read date registers */ | |
52 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 53 | dev_err(&client->dev, "%s: read error\n", __func__); |
edf1aaa3 AZ |
54 | return -EIO; |
55 | } | |
56 | ||
57 | dev_dbg(&client->dev, | |
11966adc | 58 | "%s: raw read data - counters=%02x,%02x,%02x,%02x\n", |
2a4e2b87 | 59 | __func__, buf[0], buf[1], buf[2], buf[3]); |
edf1aaa3 | 60 | |
f0c04c27 CIK |
61 | time = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | |
62 | (buf[1] << 8) | buf[0]; | |
edf1aaa3 AZ |
63 | |
64 | rtc_time_to_tm(time, tm); | |
65 | ||
66 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " | |
67 | "mday=%d, mon=%d, year=%d, wday=%d\n", | |
2a4e2b87 | 68 | __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, |
edf1aaa3 AZ |
69 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
74 | static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) | |
75 | { | |
76 | int xfer; | |
8a95b252 | 77 | unsigned char buf[6]; |
edf1aaa3 AZ |
78 | |
79 | buf[0] = DS1672_REG_CNT_BASE; | |
80 | buf[1] = secs & 0x000000FF; | |
81 | buf[2] = (secs & 0x0000FF00) >> 8; | |
82 | buf[3] = (secs & 0x00FF0000) >> 16; | |
83 | buf[4] = (secs & 0xFF000000) >> 24; | |
1716b0fe | 84 | buf[5] = 0; /* set control reg to enable counting */ |
edf1aaa3 | 85 | |
8a95b252 KG |
86 | xfer = i2c_master_send(client, buf, 6); |
87 | if (xfer != 6) { | |
2a4e2b87 | 88 | dev_err(&client->dev, "%s: send: %d\n", __func__, xfer); |
edf1aaa3 AZ |
89 | return -EIO; |
90 | } | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
edf1aaa3 AZ |
95 | static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) |
96 | { | |
97 | return ds1672_get_datetime(to_i2c_client(dev), tm); | |
98 | } | |
99 | ||
edf1aaa3 AZ |
100 | static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) |
101 | { | |
102 | return ds1672_set_mmss(to_i2c_client(dev), secs); | |
103 | } | |
104 | ||
8a95b252 KG |
105 | static int ds1672_get_control(struct i2c_client *client, u8 *status) |
106 | { | |
107 | unsigned char addr = DS1672_REG_CONTROL; | |
108 | ||
109 | struct i2c_msg msgs[] = { | |
2bfc37df S |
110 | {/* setup read ptr */ |
111 | .addr = client->addr, | |
112 | .len = 1, | |
113 | .buf = &addr | |
114 | }, | |
115 | {/* read control */ | |
116 | .addr = client->addr, | |
117 | .flags = I2C_M_RD, | |
118 | .len = 1, | |
119 | .buf = status | |
120 | }, | |
8a95b252 KG |
121 | }; |
122 | ||
123 | /* read control register */ | |
124 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { | |
2a4e2b87 | 125 | dev_err(&client->dev, "%s: read error\n", __func__); |
8a95b252 KG |
126 | return -EIO; |
127 | } | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | /* following are the sysfs callback functions */ | |
1716b0fe AZ |
133 | static ssize_t show_control(struct device *dev, struct device_attribute *attr, |
134 | char *buf) | |
8a95b252 KG |
135 | { |
136 | struct i2c_client *client = to_i2c_client(dev); | |
8a95b252 KG |
137 | u8 control; |
138 | int err; | |
139 | ||
140 | err = ds1672_get_control(client, &control); | |
141 | if (err) | |
142 | return err; | |
143 | ||
3903586a | 144 | return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) |
1716b0fe | 145 | ? "disabled" : "enabled"); |
8a95b252 | 146 | } |
1716b0fe | 147 | |
8a95b252 KG |
148 | static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); |
149 | ||
ff8371ac | 150 | static const struct rtc_class_ops ds1672_rtc_ops = { |
1716b0fe | 151 | .read_time = ds1672_rtc_read_time, |
1716b0fe | 152 | .set_mmss = ds1672_rtc_set_mmss, |
edf1aaa3 AZ |
153 | }; |
154 | ||
1716b0fe AZ |
155 | static int ds1672_probe(struct i2c_client *client, |
156 | const struct i2c_device_id *id) | |
edf1aaa3 AZ |
157 | { |
158 | int err = 0; | |
8a95b252 | 159 | u8 control; |
edf1aaa3 AZ |
160 | struct rtc_device *rtc; |
161 | ||
1716b0fe | 162 | dev_dbg(&client->dev, "%s\n", __func__); |
edf1aaa3 | 163 | |
1716b0fe AZ |
164 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
165 | return -ENODEV; | |
edf1aaa3 | 166 | |
aac8703c | 167 | rtc = devm_rtc_device_register(&client->dev, ds1672_driver.driver.name, |
1716b0fe | 168 | &ds1672_rtc_ops, THIS_MODULE); |
edf1aaa3 | 169 | |
1716b0fe AZ |
170 | if (IS_ERR(rtc)) |
171 | return PTR_ERR(rtc); | |
edf1aaa3 AZ |
172 | |
173 | i2c_set_clientdata(client, rtc); | |
174 | ||
8a95b252 KG |
175 | /* read control register */ |
176 | err = ds1672_get_control(client, &control); | |
4071ea25 AZ |
177 | if (err) { |
178 | dev_warn(&client->dev, "Unable to read the control register\n"); | |
179 | } | |
8a95b252 KG |
180 | |
181 | if (control & DS1672_REG_CONTROL_EOSC) | |
182 | dev_warn(&client->dev, "Oscillator not enabled. " | |
1716b0fe | 183 | "Set time to enable.\n"); |
8a95b252 KG |
184 | |
185 | /* Register sysfs hooks */ | |
91046a8a JG |
186 | err = device_create_file(&client->dev, &dev_attr_control); |
187 | if (err) | |
4071ea25 AZ |
188 | dev_err(&client->dev, "Unable to create sysfs entry: %s\n", |
189 | dev_attr_control.attr.name); | |
8a95b252 | 190 | |
edf1aaa3 | 191 | return 0; |
edf1aaa3 AZ |
192 | } |
193 | ||
45a63518 | 194 | static const struct i2c_device_id ds1672_id[] = { |
fe102c71 AZ |
195 | { "ds1672", 0 }, |
196 | { } | |
197 | }; | |
8ad0f5b6 | 198 | MODULE_DEVICE_TABLE(i2c, ds1672_id); |
fe102c71 | 199 | |
23194ac0 JMC |
200 | static const struct of_device_id ds1672_of_match[] = { |
201 | { .compatible = "dallas,ds1672" }, | |
202 | { } | |
203 | }; | |
204 | MODULE_DEVICE_TABLE(of, ds1672_of_match); | |
205 | ||
1716b0fe AZ |
206 | static struct i2c_driver ds1672_driver = { |
207 | .driver = { | |
208 | .name = "rtc-ds1672", | |
23194ac0 JMC |
209 | .of_match_table = of_match_ptr(ds1672_of_match), |
210 | }, | |
1716b0fe | 211 | .probe = &ds1672_probe, |
fe102c71 | 212 | .id_table = ds1672_id, |
1716b0fe AZ |
213 | }; |
214 | ||
0abc9201 | 215 | module_i2c_driver(ds1672_driver); |
edf1aaa3 AZ |
216 | |
217 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); | |
218 | MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); | |
219 | MODULE_LICENSE("GPL"); |