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
|
/*
* A SPI driver for the Ricoh RS5C348 RTC
*
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
*
* 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.
*
* The board specific init code should provide characteristics of this
* device:
* Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
*/
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/workqueue.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#define RS5C348_REG_SECS 0
#define RS5C348_REG_MINS 1
#define RS5C348_REG_HOURS 2
#define RS5C348_REG_WDAY 3
#define RS5C348_REG_DAY 4
#define RS5C348_REG_MONTH 5
#define RS5C348_REG_YEAR 6
#define RS5C348_REG_CTL1 14
#define RS5C348_REG_CTL2 15
#define RS5C348_SECS_MASK 0x7f
#define RS5C348_MINS_MASK 0x7f
#define RS5C348_HOURS_MASK 0x3f
#define RS5C348_WDAY_MASK 0x03
#define RS5C348_DAY_MASK 0x3f
#define RS5C348_MONTH_MASK 0x1f
#define RS5C348_BIT_PM 0x20 /* REG_HOURS */
#define RS5C348_BIT_Y2K 0x80 /* REG_MONTH */
#define RS5C348_BIT_24H 0x20 /* REG_CTL1 */
#define RS5C348_BIT_XSTP 0x10 /* REG_CTL2 */
#define RS5C348_BIT_VDET 0x40 /* REG_CTL2 */
#define RS5C348_CMD_W(addr) (((addr) << 4) | 0x08) /* single write */
#define RS5C348_CMD_R(addr) (((addr) << 4) | 0x0c) /* single read */
#define RS5C348_CMD_MW(addr) (((addr) << 4) | 0x00) /* burst write */
#define RS5C348_CMD_MR(addr) (((addr) << 4) | 0x04) /* burst read */
struct rs5c348_plat_data {
struct rtc_device *rtc;
int rtc_24h;
};
static int
rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct spi_device *spi = to_spi_device(dev);
struct rs5c348_plat_data *pdata = dev_get_platdata(&spi->dev);
u8 txbuf[5+7], *txp;
int ret;
/* Transfer 5 bytes before writing SEC. This gives 31us for carry. */
txp = txbuf;
txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
txbuf[1] = 0; /* dummy */
txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
txbuf[3] = 0; /* dummy */
txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
txp = &txbuf[5];
txp[RS5C348_REG_SECS] = bin2bcd(tm->tm_sec);
txp[RS5C348_REG_MINS] = bin2bcd(tm->tm_min);
if (pdata->rtc_24h) {
txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
} else {
/* hour 0 is AM12, noon is PM12 */
txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) |
(tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
}
txp[RS5C348_REG_WDAY] = bin2bcd(tm->tm_wday);
txp[RS5C348_REG_DAY] = bin2bcd(tm->tm_mday);
txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) |
(tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
txp[RS5C348_REG_YEAR] = bin2bcd(tm->tm_year % 100);
/* write in one transfer to avoid data inconsistency */
ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
udelay(62); /* Tcsr 62us */
return ret;
}
static int
rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct spi_device *spi = to_spi_device(dev);
struct rs5c348_plat_data *pdata = dev_get_platdata(&spi->dev);
u8 txbuf[5], rxbuf[7];
int ret;
/* Transfer 5 byte befores reading SEC. This gives 31us for carry. */
txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
txbuf[1] = 0; /* dummy */
txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
txbuf[3] = 0; /* dummy */
txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */
/* read in one transfer to avoid data inconsistency */
ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
rxbuf, sizeof(rxbuf));
udelay(62); /* Tcsr 62us */
if (ret < 0)
return ret;
tm->tm_sec = bcd2bin(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
if (!pdata->rtc_24h) {
if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
tm->tm_hour -= 20;
tm->tm_hour %= 12;
tm->tm_hour += 12;
} else
tm->tm_hour %= 12;
}
tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
tm->tm_mon =
bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
/* year is 1900 + tm->tm_year */
tm->tm_year = bcd2bin(rxbuf[RS5C348_REG_YEAR]) +
((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
if (rtc_valid_tm(tm) < 0) {
dev_err(&spi->dev, "retrieved date/time is not valid.\n");
rtc_time_to_tm(0, tm);
}
return 0;
}
static const struct rtc_class_ops rs5c348_rtc_ops = {
.read_time = rs5c348_rtc_read_time,
.set_time = rs5c348_rtc_set_time,
};
static struct spi_driver rs5c348_driver;
static int rs5c348_probe(struct spi_device *spi)
{
int ret;
struct rtc_device *rtc;
struct rs5c348_plat_data *pdata;
pdata = devm_kzalloc(&spi->dev, sizeof(struct rs5c348_plat_data),
GFP_KERNEL);
if (!pdata)
return -ENOMEM;
spi->dev.platform_data = pdata;
/* Check D7 of SECOND register */
ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
if (ret < 0 || (ret & 0x80)) {
dev_err(&spi->dev, "not found.\n");
goto kfree_exit;
}
dev_info(&spi->dev, "spiclk %u KHz.\n",
(spi->max_speed_hz + 500) / 1000);
/* turn RTC on if it was not on */
ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
if (ret < 0)
goto kfree_exit;
if (ret & (RS5C348_BIT_XSTP | RS5C348_BIT_VDET)) {
u8 buf[2];
struct rtc_time tm;
if (ret & RS5C348_BIT_VDET)
dev_warn(&spi->dev, "voltage-low detected.\n");
if (ret & RS5C348_BIT_XSTP)
dev_warn(&spi->dev, "oscillator-stop detected.\n");
rtc_time_to_tm(0, &tm); /* 1970/1/1 */
ret = rs5c348_rtc_set_time(&spi->dev, &tm);
if (ret < 0)
goto kfree_exit;
buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
buf[1] = 0;
ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
if (ret < 0)
goto kfree_exit;
}
ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
if (ret < 0)
goto kfree_exit;
if (ret & RS5C348_BIT_24H)
pdata->rtc_24h = 1;
rtc = devm_rtc_device_register(&spi->dev, rs5c348_driver.driver.name,
&rs5c348_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
ret = PTR_ERR(rtc);
goto kfree_exit;
}
pdata->rtc = rtc;
return 0;
kfree_exit:
return ret;
}
static struct spi_driver rs5c348_driver = {
.driver = {
.name = "rtc-rs5c348",
},
.probe = rs5c348_probe,
};
module_spi_driver(rs5c348_driver);
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:rtc-rs5c348");
|
