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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
|
/*
* An I2C driver for the NXP PCF2127 RTC
* Copyright 2013 Til-Technologies
*
* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
*
* based on the other drivers in this same directory.
*
* http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
*
* 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/slab.h>
#include <linux/module.h>
#include <linux/of.h>
#define DRV_VERSION "0.0.1"
#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
#define PCF2127_REG_SC (0x03) /* datetime */
#define PCF2127_REG_MN (0x04)
#define PCF2127_REG_HR (0x05)
#define PCF2127_REG_DM (0x06)
#define PCF2127_REG_DW (0x07)
#define PCF2127_REG_MO (0x08)
#define PCF2127_REG_YR (0x09)
static struct i2c_driver pcf2127_driver;
struct pcf2127 {
struct rtc_device *rtc;
int voltage_low; /* indicates if a low_voltage was detected */
};
/*
* In the routines that deal directly with the pcf2127 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
unsigned char buf[10] = { PCF2127_REG_CTRL1 };
/* read registers */
if (i2c_master_send(client, buf, 1) != 1 ||
i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
dev_err(&client->dev, "%s: read error\n", __func__);
return -EIO;
}
if (buf[PCF2127_REG_CTRL3] & 0x04) {
pcf2127->voltage_low = 1;
dev_info(&client->dev,
"low voltage detected, date/time is not reliable.\n");
}
dev_dbg(&client->dev,
"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
"sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
__func__,
buf[0], buf[1], buf[2],
buf[3], buf[4], buf[5],
buf[6], buf[7], buf[8], buf[9]);
tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
if (tm->tm_year < 70)
tm->tm_year += 100; /* assume we are in 1970...2069 */
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* 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 pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
unsigned char buf[8];
int i = 0, err;
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* start register address */
buf[i++] = PCF2127_REG_SC;
/* hours, minutes and seconds */
buf[i++] = bin2bcd(tm->tm_sec);
buf[i++] = bin2bcd(tm->tm_min);
buf[i++] = bin2bcd(tm->tm_hour);
buf[i++] = bin2bcd(tm->tm_mday);
buf[i++] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
buf[i++] = bin2bcd(tm->tm_mon + 1);
/* year */
buf[i++] = bin2bcd(tm->tm_year % 100);
/* write register's data */
err = i2c_master_send(client, buf, i);
if (err != i) {
dev_err(&client->dev,
"%s: err=%d", __func__, err);
return -EIO;
}
return 0;
}
#ifdef CONFIG_RTC_INTF_DEV
static int pcf2127_rtc_ioctl(struct device *dev,
unsigned int cmd, unsigned long arg)
{
struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));
switch (cmd) {
case RTC_VL_READ:
if (pcf2127->voltage_low)
dev_info(dev, "low voltage detected, date/time is not reliable.\n");
if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
sizeof(int)))
return -EFAULT;
return 0;
default:
return -ENOIOCTLCMD;
}
}
#else
#define pcf2127_rtc_ioctl NULL
#endif
static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return pcf2127_get_datetime(to_i2c_client(dev), tm);
}
static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return pcf2127_set_datetime(to_i2c_client(dev), tm);
}
static const struct rtc_class_ops pcf2127_rtc_ops = {
.ioctl = pcf2127_rtc_ioctl,
.read_time = pcf2127_rtc_read_time,
.set_time = pcf2127_rtc_set_time,
};
static int pcf2127_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf2127 *pcf2127;
dev_dbg(&client->dev, "%s\n", __func__);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
GFP_KERNEL);
if (!pcf2127)
return -ENOMEM;
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
i2c_set_clientdata(client, pcf2127);
pcf2127->rtc = devm_rtc_device_register(&client->dev,
pcf2127_driver.driver.name,
&pcf2127_rtc_ops, THIS_MODULE);
if (IS_ERR(pcf2127->rtc))
return PTR_ERR(pcf2127->rtc);
return 0;
}
static const struct i2c_device_id pcf2127_id[] = {
{ "pcf2127", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf2127_id);
#ifdef CONFIG_OF
static const struct of_device_id pcf2127_of_match[] = {
{ .compatible = "nxp,pcf2127" },
{}
};
MODULE_DEVICE_TABLE(of, pcf2127_of_match);
#endif
static struct i2c_driver pcf2127_driver = {
.driver = {
.name = "rtc-pcf2127",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(pcf2127_of_match),
},
.probe = pcf2127_probe,
.id_table = pcf2127_id,
};
module_i2c_driver(pcf2127_driver);
MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
|
