aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-ds1286.c
blob: bf430f9091ed0ba3b10b66dfeab207ca4cda3287 (plain) (blame)
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
409
410
411
/*
 * DS1286 Real Time Clock interface for Linux
 *
 * Copyright (C) 1998, 1999, 2000 Ralf Baechle
 * Copyright (C) 2008 Thomas Bogendoerfer
 *
 * Based on code written by Paul Gortmaker.
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/bcd.h>
#include <linux/ds1286.h>
#include <linux/io.h>
#include <linux/slab.h>

#define DRV_VERSION		"1.0"

struct ds1286_priv {
	struct rtc_device *rtc;
	u32 __iomem *rtcregs;
	size_t size;
	unsigned long baseaddr;
	spinlock_t lock;
};

static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
{
	return __raw_readl(&priv->rtcregs[reg]) & 0xff;
}

static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
{
	__raw_writel(data, &priv->rtcregs[reg]);
}

#ifdef CONFIG_RTC_INTF_DEV

static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;
	unsigned char val;

	switch (cmd) {
	case RTC_AIE_OFF:
		/* Mask alarm int. enab. bit	*/
		spin_lock_irqsave(&priv->lock, flags);
		val = ds1286_rtc_read(priv, RTC_CMD);
		val |=  RTC_TDM;
		ds1286_rtc_write(priv, val, RTC_CMD);
		spin_unlock_irqrestore(&priv->lock, flags);
		break;
	case RTC_AIE_ON:
		/* Allow alarm interrupts.	*/
		spin_lock_irqsave(&priv->lock, flags);
		val = ds1286_rtc_read(priv, RTC_CMD);
		val &=  ~RTC_TDM;
		ds1286_rtc_write(priv, val, RTC_CMD);
		spin_unlock_irqrestore(&priv->lock, flags);
		break;
	case RTC_WIE_OFF:
		/* Mask watchdog int. enab. bit	*/
		spin_lock_irqsave(&priv->lock, flags);
		val = ds1286_rtc_read(priv, RTC_CMD);
		val |= RTC_WAM;
		ds1286_rtc_write(priv, val, RTC_CMD);
		spin_unlock_irqrestore(&priv->lock, flags);
		break;
	case RTC_WIE_ON:
		/* Allow watchdog interrupts.	*/
		spin_lock_irqsave(&priv->lock, flags);
		val = ds1286_rtc_read(priv, RTC_CMD);
		val &= ~RTC_WAM;
		ds1286_rtc_write(priv, val, RTC_CMD);
		spin_unlock_irqrestore(&priv->lock, flags);
		break;
	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

#else
#define ds1286_ioctl    NULL
#endif

#ifdef CONFIG_PROC_FS

static int ds1286_proc(struct device *dev, struct seq_file *seq)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned char month, cmd, amode;
	const char *s;

	month = ds1286_rtc_read(priv, RTC_MONTH);
	seq_printf(seq,
		   "oscillator\t: %s\n"
		   "square_wave\t: %s\n",
		   (month & RTC_EOSC) ? "disabled" : "enabled",
		   (month & RTC_ESQW) ? "disabled" : "enabled");

	amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |
		((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |
		((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);
	switch (amode) {
	case 7:
		s = "each minute";
		break;
	case 3:
		s = "minutes match";
		break;
	case 1:
		s = "hours and minutes match";
		break;
	case 0:
		s = "days, hours and minutes match";
		break;
	default:
		s = "invalid";
		break;
	}
	seq_printf(seq, "alarm_mode\t: %s\n", s);

	cmd = ds1286_rtc_read(priv, RTC_CMD);
	seq_printf(seq,
		   "alarm_enable\t: %s\n"
		   "wdog_alarm\t: %s\n"
		   "alarm_mask\t: %s\n"
		   "wdog_alarm_mask\t: %s\n"
		   "interrupt_mode\t: %s\n"
		   "INTB_mode\t: %s_active\n"
		   "interrupt_pins\t: %s\n",
		   (cmd & RTC_TDF) ? "yes" : "no",
		   (cmd & RTC_WAF) ? "yes" : "no",
		   (cmd & RTC_TDM) ? "disabled" : "enabled",
		   (cmd & RTC_WAM) ? "disabled" : "enabled",
		   (cmd & RTC_PU_LVL) ? "pulse" : "level",
		   (cmd & RTC_IBH_LO) ? "low" : "high",
		   (cmd & RTC_IPSW) ? "unswapped" : "swapped");
	return 0;
}

#else
#define ds1286_proc     NULL
#endif

static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned char save_control;
	unsigned long flags;
	unsigned long uip_watchdog = jiffies;

	/*
	 * read RTC once any update in progress is done. The update
	 * can take just over 2ms. We wait 10 to 20ms. There is no need to
	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
	 * If you need to know *exactly* when a second has started, enable
	 * periodic update complete interrupts, (via ioctl) and then
	 * immediately read /dev/rtc which will block until you get the IRQ.
	 * Once the read clears, read the RTC time (again via ioctl). Easy.
	 */

	if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
		while (time_before(jiffies, uip_watchdog + 2*HZ/100))
			barrier();

	/*
	 * Only the values that we read from the RTC are set. We leave
	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	 * by the RTC when initially set to a non-zero value.
	 */
	spin_lock_irqsave(&priv->lock, flags);
	save_control = ds1286_rtc_read(priv, RTC_CMD);
	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);

	tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);
	tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);
	tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;
	tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);
	tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;
	tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR);

	ds1286_rtc_write(priv, save_control, RTC_CMD);
	spin_unlock_irqrestore(&priv->lock, flags);

	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon);
	tm->tm_year = bcd2bin(tm->tm_year);

	/*
	 * Account for differences between how the RTC uses the values
	 * and how they are defined in a struct rtc_time;
	 */
	if (tm->tm_year < 45)
		tm->tm_year += 30;
	tm->tm_year += 40;
	if (tm->tm_year < 70)
		tm->tm_year += 100;

	tm->tm_mon--;

	return rtc_valid_tm(tm);
}

static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned char mon, day, hrs, min, sec;
	unsigned char save_control;
	unsigned int yrs;
	unsigned long flags;

	yrs = tm->tm_year + 1900;
	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
	day = tm->tm_mday;
	hrs = tm->tm_hour;
	min = tm->tm_min;
	sec = tm->tm_sec;

	if (yrs < 1970)
		return -EINVAL;

	yrs -= 1940;
	if (yrs > 255)    /* They are unsigned */
		return -EINVAL;

	if (yrs >= 100)
		yrs -= 100;

	sec = bin2bcd(sec);
	min = bin2bcd(min);
	hrs = bin2bcd(hrs);
	day = bin2bcd(day);
	mon = bin2bcd(mon);
	yrs = bin2bcd(yrs);

	spin_lock_irqsave(&priv->lock, flags);
	save_control = ds1286_rtc_read(priv, RTC_CMD);
	ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);

	ds1286_rtc_write(priv, yrs, RTC_YEAR);
	ds1286_rtc_write(priv, mon, RTC_MONTH);
	ds1286_rtc_write(priv, day, RTC_DATE);
	ds1286_rtc_write(priv, hrs, RTC_HOURS);
	ds1286_rtc_write(priv, min, RTC_MINUTES);
	ds1286_rtc_write(priv, sec, RTC_SECONDS);
	ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND);

	ds1286_rtc_write(priv, save_control, RTC_CMD);
	spin_unlock_irqrestore(&priv->lock, flags);
	return 0;
}

static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned char cmd;
	unsigned long flags;

	/*
	 * Only the values that we read from the RTC are set. That
	 * means only tm_wday, tm_hour, tm_min.
	 */
	spin_lock_irqsave(&priv->lock, flags);
	alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;
	alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM)  & 0x1f;
	alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM)    & 0x07;
	cmd = ds1286_rtc_read(priv, RTC_CMD);
	spin_unlock_irqrestore(&priv->lock, flags);

	alm->time.tm_min = bcd2bin(alm->time.tm_min);
	alm->time.tm_hour = bcd2bin(alm->time.tm_hour);
	alm->time.tm_sec = 0;
	return 0;
}

static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct ds1286_priv *priv = dev_get_drvdata(dev);
	unsigned char hrs, min, sec;

	hrs = alm->time.tm_hour;
	min = alm->time.tm_min;
	sec = alm->time.tm_sec;

	if (hrs >= 24)
		hrs = 0xff;

	if (min >= 60)
		min = 0xff;

	if (sec != 0)
		return -EINVAL;

	min = bin2bcd(min);
	hrs = bin2bcd(hrs);

	spin_lock(&priv->lock);
	ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);
	ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);
	spin_unlock(&priv->lock);

	return 0;
}

static const struct rtc_class_ops ds1286_ops = {
	.ioctl   	= ds1286_ioctl,
	.proc   	= ds1286_proc,
	.read_time	= ds1286_read_time,
	.set_time	= ds1286_set_time,
	.read_alarm	= ds1286_read_alarm,
	.set_alarm	= ds1286_set_alarm,
};

static int __devinit ds1286_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	struct ds1286_priv *priv;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;
	priv = kzalloc(sizeof(struct ds1286_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->size = res->end - res->start + 1;
	if (!request_mem_region(res->start, priv->size, pdev->name)) {
		ret = -EBUSY;
		goto out;
	}
	priv->baseaddr = res->start;
	priv->rtcregs = ioremap(priv->baseaddr, priv->size);
	if (!priv->rtcregs) {
		ret = -ENOMEM;
		goto out;
	}
	spin_lock_init(&priv->lock);
	rtc = rtc_device_register("ds1286", &pdev->dev,
				  &ds1286_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		ret = PTR_ERR(rtc);
		goto out;
	}
	priv->rtc = rtc;
	platform_set_drvdata(pdev, priv);
	return 0;

out:
	if (priv->rtc)
		rtc_device_unregister(priv->rtc);
	if (priv->rtcregs)
		iounmap(priv->rtcregs);
	if (priv->baseaddr)
		release_mem_region(priv->baseaddr, priv->size);
	kfree(priv);
	return ret;
}

static int __devexit ds1286_remove(struct platform_device *pdev)
{
	struct ds1286_priv *priv = platform_get_drvdata(pdev);

	rtc_device_unregister(priv->rtc);
	iounmap(priv->rtcregs);
	release_mem_region(priv->baseaddr, priv->size);
	kfree(priv);
	return 0;
}

static struct platform_driver ds1286_platform_driver = {
	.driver		= {
		.name	= "rtc-ds1286",
		.owner	= THIS_MODULE,
	},
	.probe		= ds1286_probe,
	.remove		= __devexit_p(ds1286_remove),
};

static int __init ds1286_init(void)
{
	return platform_driver_register(&ds1286_platform_driver);
}

static void __exit ds1286_exit(void)
{
	platform_driver_unregister(&ds1286_platform_driver);
}

MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
MODULE_DESCRIPTION("DS1286 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:rtc-ds1286");

module_init(ds1286_init);
module_exit(ds1286_exit);