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
|
/* drivers/rtc/rtc-r9701.c
*
* Driver for Epson RTC-9701JE
*
* Copyright (C) 2008 Magnus Damm
*
* Based on drivers/rtc/rtc-max6902.c
*
* Copyright (C) 2006 8D Technologies inc.
* Copyright (C) 2004 Compulab Ltd.
*
* 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/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#define RSECCNT 0x00 /* Second Counter */
#define RMINCNT 0x01 /* Minute Counter */
#define RHRCNT 0x02 /* Hour Counter */
#define RWKCNT 0x03 /* Week Counter */
#define RDAYCNT 0x04 /* Day Counter */
#define RMONCNT 0x05 /* Month Counter */
#define RYRCNT 0x06 /* Year Counter */
#define R100CNT 0x07 /* Y100 Counter */
#define RMINAR 0x08 /* Minute Alarm */
#define RHRAR 0x09 /* Hour Alarm */
#define RWKAR 0x0a /* Week/Day Alarm */
#define RTIMCNT 0x0c /* Interval Timer */
#define REXT 0x0d /* Extension Register */
#define RFLAG 0x0e /* RTC Flag Register */
#define RCR 0x0f /* RTC Control Register */
static int write_reg(struct device *dev, int address, unsigned char data)
{
struct spi_device *spi = to_spi_device(dev);
unsigned char buf[2];
buf[0] = address & 0x7f;
buf[1] = data;
return spi_write(spi, buf, ARRAY_SIZE(buf));
}
static int read_regs(struct device *dev, unsigned char *regs, int no_regs)
{
struct spi_device *spi = to_spi_device(dev);
u8 txbuf[1], rxbuf[1];
int k, ret;
ret = 0;
for (k = 0; ret == 0 && k < no_regs; k++) {
txbuf[0] = 0x80 | regs[k];
ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
regs[k] = rxbuf[0];
}
return ret;
}
static int r9701_get_datetime(struct device *dev, struct rtc_time *dt)
{
struct spi_device *spi = to_spi_device(dev);
unsigned long time;
int ret;
unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
RDAYCNT, RMONCNT, RYRCNT };
ret = read_regs(&spi->dev, buf, ARRAY_SIZE(buf));
if (ret)
return ret;
memset(dt, 0, sizeof(*dt));
dt->tm_sec = BCD2BIN(buf[0]); /* RSECCNT */
dt->tm_min = BCD2BIN(buf[1]); /* RMINCNT */
dt->tm_hour = BCD2BIN(buf[2]); /* RHRCNT */
dt->tm_mday = BCD2BIN(buf[3]); /* RDAYCNT */
dt->tm_mon = BCD2BIN(buf[4]) - 1; /* RMONCNT */
dt->tm_year = BCD2BIN(buf[5]) + 100; /* RYRCNT */
/* the rtc device may contain illegal values on power up
* according to the data sheet. make sure they are valid.
*/
ret = rtc_valid_tm(dt);
if (ret)
return ret;
/* don't bother with yday, wday and isdst.
* let the rtc core calculate them for us.
*/
rtc_tm_to_time(dt, &time);
rtc_time_to_tm(time, dt);
return 0;
}
static int r9701_set_datetime(struct device *dev, struct rtc_time *dt)
{
int ret, year;
year = dt->tm_year + 1900;
if (year >= 2100 || year < 2000)
return -EINVAL;
ret = write_reg(dev, RHRCNT, BIN2BCD(dt->tm_hour));
ret |= write_reg(dev, RMINCNT, BIN2BCD(dt->tm_min));
ret |= write_reg(dev, RSECCNT, BIN2BCD(dt->tm_sec));
ret |= write_reg(dev, RDAYCNT, BIN2BCD(dt->tm_mday));
ret |= write_reg(dev, RMONCNT, BIN2BCD(dt->tm_mon + 1));
ret |= write_reg(dev, RYRCNT, BIN2BCD(dt->tm_year - 100));
ret |= write_reg(dev, RWKCNT, 1 << dt->tm_wday);
return ret;
}
static const struct rtc_class_ops r9701_rtc_ops = {
.read_time = r9701_get_datetime,
.set_time = r9701_set_datetime,
};
static int __devinit r9701_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
unsigned char tmp;
int res;
rtc = rtc_device_register("r9701",
&spi->dev, &r9701_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
dev_set_drvdata(&spi->dev, rtc);
spi->mode = SPI_MODE_3;
spi->bits_per_word = 8;
spi_setup(spi);
tmp = R100CNT;
res = read_regs(&spi->dev, &tmp, 1);
if (res || tmp != 0x20) {
rtc_device_unregister(rtc);
return res;
}
return 0;
}
static int __devexit r9701_remove(struct spi_device *spi)
{
struct rtc_device *rtc = dev_get_drvdata(&spi->dev);
rtc_device_unregister(rtc);
return 0;
}
static struct spi_driver r9701_driver = {
.driver = {
.name = "rtc-r9701",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = r9701_probe,
.remove = __devexit_p(r9701_remove),
};
static __init int r9701_init(void)
{
return spi_register_driver(&r9701_driver);
}
module_init(r9701_init);
static __exit void r9701_exit(void)
{
spi_unregister_driver(&r9701_driver);
}
module_exit(r9701_exit);
MODULE_DESCRIPTION("r9701 spi RTC driver");
MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
MODULE_LICENSE("GPL");
|
