1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/*
* An I2C driver for the PCF85063 RTC
* Copyright 2014 Rose Technology
*
* Author: Søren Andersen <san@rosetechnology.dk>
* Maintainers: http://www.nslu2-linux.org/
*
* based on the other drivers in this same directory.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/module.h>
#define DRV_VERSION "0.0.1"
#define PCF85063_REG_CTRL1 0x00 /* status */
#define PCF85063_REG_CTRL2 0x01
#define PCF85063_REG_SC 0x04 /* datetime */
#define PCF85063_REG_MN 0x05
#define PCF85063_REG_HR 0x06
#define PCF85063_REG_DM 0x07
#define PCF85063_REG_DW 0x08
#define PCF85063_REG_MO 0x09
#define PCF85063_REG_YR 0x0A
#define PCF85063_MO_C 0x80 /* century */
static struct i2c_driver pcf85063_driver;
struct pcf85063 {
struct rtc_device *rtc;
int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
int voltage_low; /* indicates if a low_voltage was detected */
};
/*
* In the routines that deal directly with the pcf85063 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct pcf85063 *pcf85063 = i2c_get_clientdata(client);
unsigned char buf[13] = { PCF85063_REG_CTRL1 };
struct i2c_msg msgs[] = {
{/* setup read ptr */
.addr = client->addr,
.len = 1,
.buf = buf
},
{/* read status + date */
.addr = client->addr,
.flags = I2C_M_RD,
.len = 13,
.buf = buf
},
};
/* read registers */
if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
tm->tm_sec = bcd2bin(buf[PCF85063_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[PCF85063_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[PCF85063_REG_HR] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(buf[PCF85063_REG_DM] & 0x3F);
tm->tm_wday = buf[PCF85063_REG_DW] & 0x07;
tm->tm_mon = bcd2bin(buf[PCF85063_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(buf[PCF85063_REG_YR]);
if (tm->tm_year < 70)
tm->tm_year += 100; /* assume we are in 1970...2069 */
/* detect the polarity heuristically. see note above. */
pcf85063->c_polarity = (buf[PCF85063_REG_MO] & PCF85063_MO_C) ?
(tm->tm_year >= 100) : (tm->tm_year < 100);
/* the clock can give out invalid datetime, but we cannot return
* -EINVAL otherwise hwclock will refuse to set the time on bootup.
*/
if (rtc_valid_tm(tm) < 0)
dev_err(&client->dev, "retrieved date/time is not valid.\n");
return 0;
}
static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
int i = 0, err = 0;
unsigned char buf[11];
/* Control & status */
buf[PCF85063_REG_CTRL1] = 0;
buf[PCF85063_REG_CTRL2] = 5;
/* hours, minutes and seconds */
buf[PCF85063_REG_SC] = bin2bcd(tm->tm_sec) & 0x7F;
buf[PCF85063_REG_MN] = bin2bcd(tm->tm_min);
buf[PCF85063_REG_HR] = bin2bcd(tm->tm_hour);
/* Day of month, 1 - 31 */
buf[PCF85063_REG_DM] = bin2bcd(tm->tm_mday);
/* Day, 0 - 6 */
buf[PCF85063_REG_DW] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
buf[PCF85063_REG_MO] = bin2bcd(tm->tm_mon + 1);
/* year and century */
buf[PCF85063_REG_YR] = bin2bcd(tm->tm_year % 100);
/* write register's data */
for (i = 0; i < sizeof(buf); i++) {
unsigned char data[2] = { i, buf[i] };
err = i2c_master_send(client, data, sizeof(data));
if (err != sizeof(data)) {
dev_err(&client->dev, "%s: err=%d addr=%02x, data=%02x\n",
__func__, err, data[0], data[1]);
return -EIO;
}
}
return 0;
}
static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return pcf85063_get_datetime(to_i2c_client(dev), tm);
}
static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return pcf85063_set_datetime(to_i2c_client(dev), tm);
}
static const struct rtc_class_ops pcf85063_rtc_ops = {
.read_time = pcf85063_rtc_read_time,
.set_time = pcf85063_rtc_set_time
};
static int pcf85063_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf85063 *pcf85063;
dev_dbg(&client->dev, "%s\n", __func__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
GFP_KERNEL);
if (!pcf85063)
return -ENOMEM;
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
i2c_set_clientdata(client, pcf85063);
pcf85063->rtc = devm_rtc_device_register(&client->dev,
pcf85063_driver.driver.name,
&pcf85063_rtc_ops, THIS_MODULE);
return PTR_ERR_OR_ZERO(pcf85063->rtc);
}
static const struct i2c_device_id pcf85063_id[] = {
{ "pcf85063", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf85063_id);
#ifdef CONFIG_OF
static const struct of_device_id pcf85063_of_match[] = {
{ .compatible = "nxp,pcf85063" },
{}
};
MODULE_DEVICE_TABLE(of, pcf85063_of_match);
#endif
static struct i2c_driver pcf85063_driver = {
.driver = {
.name = "rtc-pcf85063",
.of_match_table = of_match_ptr(pcf85063_of_match),
},
.probe = pcf85063_probe,
.id_table = pcf85063_id,
};
module_i2c_driver(pcf85063_driver);
MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
MODULE_DESCRIPTION("PCF85063 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
|
