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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
|
/*
* Driver for NEC VR4100 series Real Time Clock unit.
*
* Copyright (C) 2003-2008 Yoichi Yuasa <yuasa@linux-mips.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/log2.h>
#include <asm/div64.h>
#include <asm/io.h>
#include <asm/uaccess.h>
MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
MODULE_LICENSE("GPL v2");
/* RTC 1 registers */
#define ETIMELREG 0x00
#define ETIMEMREG 0x02
#define ETIMEHREG 0x04
/* RFU */
#define ECMPLREG 0x08
#define ECMPMREG 0x0a
#define ECMPHREG 0x0c
/* RFU */
#define RTCL1LREG 0x10
#define RTCL1HREG 0x12
#define RTCL1CNTLREG 0x14
#define RTCL1CNTHREG 0x16
#define RTCL2LREG 0x18
#define RTCL2HREG 0x1a
#define RTCL2CNTLREG 0x1c
#define RTCL2CNTHREG 0x1e
/* RTC 2 registers */
#define TCLKLREG 0x00
#define TCLKHREG 0x02
#define TCLKCNTLREG 0x04
#define TCLKCNTHREG 0x06
/* RFU */
#define RTCINTREG 0x1e
#define TCLOCK_INT 0x08
#define RTCLONG2_INT 0x04
#define RTCLONG1_INT 0x02
#define ELAPSEDTIME_INT 0x01
#define RTC_FREQUENCY 32768
#define MAX_PERIODIC_RATE 6553
static void __iomem *rtc1_base;
static void __iomem *rtc2_base;
#define rtc1_read(offset) readw(rtc1_base + (offset))
#define rtc1_write(offset, value) writew((value), rtc1_base + (offset))
#define rtc2_read(offset) readw(rtc2_base + (offset))
#define rtc2_write(offset, value) writew((value), rtc2_base + (offset))
static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */
static DEFINE_SPINLOCK(rtc_lock);
static char rtc_name[] = "RTC";
static unsigned long periodic_count;
static unsigned int alarm_enabled;
static int aie_irq;
static int pie_irq;
static inline unsigned long read_elapsed_second(void)
{
unsigned long first_low, first_mid, first_high;
unsigned long second_low, second_mid, second_high;
do {
first_low = rtc1_read(ETIMELREG);
first_mid = rtc1_read(ETIMEMREG);
first_high = rtc1_read(ETIMEHREG);
second_low = rtc1_read(ETIMELREG);
second_mid = rtc1_read(ETIMEMREG);
second_high = rtc1_read(ETIMEHREG);
} while (first_low != second_low || first_mid != second_mid ||
first_high != second_high);
return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
}
static inline void write_elapsed_second(unsigned long sec)
{
spin_lock_irq(&rtc_lock);
rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
spin_unlock_irq(&rtc_lock);
}
static void vr41xx_rtc_release(struct device *dev)
{
spin_lock_irq(&rtc_lock);
rtc1_write(ECMPLREG, 0);
rtc1_write(ECMPMREG, 0);
rtc1_write(ECMPHREG, 0);
rtc1_write(RTCL1LREG, 0);
rtc1_write(RTCL1HREG, 0);
spin_unlock_irq(&rtc_lock);
disable_irq(aie_irq);
disable_irq(pie_irq);
}
static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
{
unsigned long epoch_sec, elapsed_sec;
epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
elapsed_sec = read_elapsed_second();
rtc_time_to_tm(epoch_sec + elapsed_sec, time);
return 0;
}
static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
{
unsigned long epoch_sec, current_sec;
epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
time->tm_hour, time->tm_min, time->tm_sec);
write_elapsed_second(current_sec - epoch_sec);
return 0;
}
static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
unsigned long low, mid, high;
struct rtc_time *time = &wkalrm->time;
spin_lock_irq(&rtc_lock);
low = rtc1_read(ECMPLREG);
mid = rtc1_read(ECMPMREG);
high = rtc1_read(ECMPHREG);
wkalrm->enabled = alarm_enabled;
spin_unlock_irq(&rtc_lock);
rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
return 0;
}
static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
unsigned long alarm_sec;
struct rtc_time *time = &wkalrm->time;
alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
time->tm_hour, time->tm_min, time->tm_sec);
spin_lock_irq(&rtc_lock);
if (alarm_enabled)
disable_irq(aie_irq);
rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
if (wkalrm->enabled)
enable_irq(aie_irq);
alarm_enabled = wkalrm->enabled;
spin_unlock_irq(&rtc_lock);
return 0;
}
static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case RTC_EPOCH_READ:
return put_user(epoch, (unsigned long __user *)arg);
case RTC_EPOCH_SET:
/* Doesn't support before 1900 */
if (arg < 1900)
return -EINVAL;
epoch = arg;
break;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
spin_lock_irq(&rtc_lock);
if (enabled) {
if (!alarm_enabled) {
enable_irq(aie_irq);
alarm_enabled = 1;
}
} else {
if (alarm_enabled) {
disable_irq(aie_irq);
alarm_enabled = 0;
}
}
spin_unlock_irq(&rtc_lock);
return 0;
}
static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = (struct platform_device *)dev_id;
struct rtc_device *rtc = platform_get_drvdata(pdev);
rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
rtc_update_irq(rtc, 1, RTC_AF);
return IRQ_HANDLED;
}
static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = (struct platform_device *)dev_id;
struct rtc_device *rtc = platform_get_drvdata(pdev);
unsigned long count = periodic_count;
rtc2_write(RTCINTREG, RTCLONG1_INT);
rtc1_write(RTCL1LREG, count);
rtc1_write(RTCL1HREG, count >> 16);
rtc_update_irq(rtc, 1, RTC_PF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops vr41xx_rtc_ops = {
.release = vr41xx_rtc_release,
.ioctl = vr41xx_rtc_ioctl,
.read_time = vr41xx_rtc_read_time,
.set_time = vr41xx_rtc_set_time,
.read_alarm = vr41xx_rtc_read_alarm,
.set_alarm = vr41xx_rtc_set_alarm,
};
static int rtc_probe(struct platform_device *pdev)
{
struct resource *res;
struct rtc_device *rtc;
int retval;
if (pdev->num_resources != 4)
return -EBUSY;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res
|