summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-m48t59.c
blob: ed671e29e07d92292b4935c889ac3f73931f4744 (plain)
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
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
/*
 * ST M48T59 RTC driver
 *
 * Copyright (c) 2007 Wind River Systems, Inc.
 *
 * Author: Mark Zhan <rongkai.zhan@windriver.com>
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/rtc/m48t59.h>
#include <linux/bcd.h>

#ifndef NO_IRQ
#define NO_IRQ	(-1)
#endif

#define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
#define M48T59_WRITE(val, reg) \
	(pdata->write_byte(dev, pdata->offset + reg, val))

#define M48T59_SET_BITS(mask, reg)	\
	M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
#define M48T59_CLEAR_BITS(mask, reg)	\
	M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))

struct m48t59_private {
	void __iomem *ioaddr;
	int irq;
	struct rtc_device *rtc;
	spinlock_t lock; /* serialize the NVRAM and RTC access */
};

/*
 * This is the generic access method when the chip is memory-mapped
 */
static void
m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);

	writeb(val, m48t59->ioaddr+ofs);
}

static u8
m48t59_mem_readb(struct device *dev, u32 ofs)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);

	return readb(m48t59->ioaddr+ofs);
}

/*
 * NOTE: M48T59 only uses BCD mode
 */
static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	unsigned long flags;
	u8 val;

	spin_lock_irqsave(&m48t59->lock, flags);
	/* Issue the READ command */
	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);

	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR));
	/* tm_mon is 0-11 */
	tm->tm_mon	= bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
	tm->tm_mday	= bcd2bin(M48T59_READ(M48T59_MDAY));

	val = M48T59_READ(M48T59_WDAY);
	if ((pdata->type == M48T59RTC_TYPE_M48T59) &&
	    (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) {
		dev_dbg(dev, "Century bit is enabled\n");
		tm->tm_year += 100;	/* one century */
	}

	tm->tm_wday	= bcd2bin(val & 0x07);
	tm->tm_hour	= bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
	tm->tm_min	= bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F);
	tm->tm_sec	= bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F);

	/* Clear the READ bit */
	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
	spin_unlock_irqrestore(&m48t59->lock, flags);

	dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n",
		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
		tm->tm_hour, tm->tm_min, tm->tm_sec);
	return 0;
}

static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	unsigned long flags;
	u8 val = 0;

	dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
		tm->tm_hour, tm->tm_min, tm->tm_sec);

	spin_lock_irqsave(&m48t59->lock, flags);
	/* Issue the WRITE command */
	M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);

	M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC);
	M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN);
	M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR);
	M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY);
	/* tm_mon is 0-11 */
	M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
	M48T59_WRITE(bin2bcd(tm->tm_year % 100), M48T59_YEAR);

	if (pdata->type == M48T59RTC_TYPE_M48T59 && (tm->tm_year / 100))
		val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
	val |= (bin2bcd(tm->tm_wday) & 0x07);
	M48T59_WRITE(val, M48T59_WDAY);

	/* Clear the WRITE bit */
	M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
	spin_unlock_irqrestore(&m48t59->lock, flags);
	return 0;
}

/*
 * Read alarm time and date in RTC
 */
static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	struct rtc_time *tm = &alrm->time;
	unsigned long flags;
	u8 val;

	/* If no irq, we don't support ALARM */
	if (m48t59->irq == NO_IRQ)
		return -EIO;

	spin_lock_irqsave(&m48t59->lock, flags);
	/* Issue the READ command */
	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);

	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
	/* tm_mon is 0-11 */
	tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;

	val = M48T59_READ(M48T59_WDAY);
	if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
		tm->tm_year += 100;	/* one century */

	tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE));
	tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR));
	tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN));
	tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC));

	/* Clear the READ bit */
	M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
	spin_unlock_irqrestore(&m48t59->lock, flags);

	dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
		tm->tm_hour, tm->tm_min, tm->tm_sec);
	return 0;
}

/*
 * Set alarm time and date in RTC
 */
static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	struct rtc_time *tm = &alrm->time;
	u8 mday, hour, min, sec;
	unsigned long flags;

	/* If no irq, we don't support ALARM */
	if (m48t59->irq == NO_IRQ)
		return -EIO;

	/*
	 * 0xff means "always match"
	 */
	mday = tm->tm_mday;
	mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
	if (mday == 0xff)
		mday = M48T59_READ(M48T59_MDAY);

	hour = tm->tm_hour;
	hour = (hour < 24) ? bin2bcd(hour) : 0x00;

	min = tm->tm_min;
	min = (min < 60) ? bin2bcd(min) : 0x00;

	sec = tm->tm_sec;
	sec = (sec < 60) ? bin2bcd(sec) : 0x00;

	spin_lock_irqsave(&m48t59->lock, flags);
	/* Issue the WRITE command */
	M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);

	M48T59_WRITE(mday, M48T59_ALARM_DATE);
	M48T59_WRITE(hour, M48T59_ALARM_HOUR);
	M48T59_WRITE(min, M48T59_ALARM_MIN);
	M48T59_WRITE(sec, M48T59_ALARM_SEC);

	/* Clear the WRITE bit */
	M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
	spin_unlock_irqrestore(&m48t59->lock, flags);

	dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n",
		tm->tm_year + 1900, tm->tm_mon, tm->tm_mday,
		tm->tm_hour, tm->tm_min, tm->tm_sec);
	return 0;
}

/*
 * Handle commands from user-space
 */
static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd,
			unsigned long arg)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	unsigned long flags;
	int ret = 0;

	spin_lock_irqsave(&m48t59->lock, flags);
	switch (cmd) {
	case RTC_AIE_OFF:	/* alarm interrupt off */
		M48T59_WRITE(0x00, M48T59_INTR);
		break;
	case RTC_AIE_ON:	/* alarm interrupt on */
		M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
		break;
	default:
		ret = -ENOIOCTLCMD;
		break;
	}
	spin_unlock_irqrestore(&m48t59->lock, flags);

	return ret;
}

static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	unsigned long flags;
	u8 val;

	spin_lock_irqsave(&m48t59->lock, flags);
	val = M48T59_READ(M48T59_FLAGS);
	spin_unlock_irqrestore(&m48t59->lock, flags);

	seq_printf(seq, "battery\t\t: %s\n",
		 (val & M48T59_FLAGS_BF) ? "low" : "normal");
	return 0;
}

/*
 * IRQ handler for the RTC
 */
static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
{
	struct device *dev = (struct device *)dev_id;
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	u8 event;

	spin_lock(&m48t59->lock);
	event = M48T59_READ(M48T59_FLAGS);
	spin_unlock(&m48t59->lock);

	if (event & M48T59_FLAGS_AF) {
		rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

static const struct rtc_class_ops m48t59_rtc_ops = {
	.ioctl		= m48t59_rtc_ioctl,
	.read_time	= m48t59_rtc_read_time,
	.set_time	= m48t59_rtc_set_time,
	.read_alarm	= m48t59_rtc_readalarm,
	.set_alarm	= m48t59_rtc_setalarm,
	.proc		= m48t59_rtc_proc,
};

static const struct rtc_class_ops m48t02_rtc_ops = {
	.read_time	= m48t59_rtc_read_time,
	.set_time	= m48t59_rtc_set_time,
};

static ssize_t m48t59_nvram_read(struct kobject *kobj,
				struct bin_attribute *bin_attr,
				char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	ssize_t cnt = 0;
	unsigned long flags;

	for (; size > 0 && pos < pdata->offset; cnt++, size--) {
		spin_lock_irqsave(&m48t59->lock, flags);
		*buf++ = M48T59_READ(cnt);
		spin_unlock_irqrestore(&m48t59->lock, flags);
	}

	return cnt;
}

static ssize_t m48t59_nvram_write(struct kobject *kobj,
				struct bin_attribute *bin_attr,
				char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	ssize_t cnt = 0;
	unsigned long flags;

	for (; size > 0 && pos < pdata->offset; cnt++, size--) {
		spin_lock_irqsave(&m48t59->lock, flags);
		M48T59_WRITE(*buf++, cnt);
		spin_unlock_irqrestore(&m48t59->lock, flags);
	}

	return cnt;
}

static struct bin_attribute m48t59_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
		.owner = THIS_MODULE,
	},
	.read = m48t59_nvram_read,
	.write = m48t59_nvram_write,
};

static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
{
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
	struct m48t59_private *m48t59 = NULL;
	struct resource *res;
	int ret = -ENOMEM;
	char *name;
	const struct rtc_class_ops *ops;

	/* This chip could be memory-mapped or I/O-mapped */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
		if (!res)
			return -EINVAL;
	}

	if (res->flags & IORESOURCE_IO) {
		/* If we are I/O-mapped, the platform should provide
		 * the operations accessing chip registers.
		 */
		if (!pdata || !pdata->write_byte || !pdata->read_byte)
			return -EINVAL;
	} else if (res->flags & IORESOURCE_MEM) {
		/* we are memory-mapped */
		if (!pdata) {
			pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
			if (!pdata)
				return -ENOMEM;
			/* Ensure we only kmalloc platform data once */
			pdev->dev.platform_data = pdata;
		}
		if (!pdata->type)
			pdata->type = M48T59RTC_TYPE_M48T59;

		/* Try to use the generic memory read/write ops */
		if (!pdata->write_byte)
			pdata->write_byte = m48t59_mem_writeb;
		if (!pdata->read_byte)
			pdata->read_byte = m48t59_mem_readb;
	}

	m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL);
	if (!m48t59)
		return -ENOMEM;

	m48t59->ioaddr = pdata->ioaddr;

	if (!m48t59->ioaddr) {
		/* ioaddr not mapped externally */
		m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1);
		if (!m48t59->ioaddr)
			goto out;
	}

	/* Try to get irq number. We also can work in
	 * the mode without IRQ.
	 */
	m48t59->irq = platform_get_irq(pdev, 0);
	if (m48t59->irq < 0)
		m48t59->irq = NO_IRQ;

	if (m48t59->irq != NO_IRQ) {
		ret = request_irq(m48t59->irq, m48t59_rtc_interrupt,
			IRQF_SHARED, "rtc-m48t59", &pdev->dev);
		if (ret)
			goto out;
	}
	switch (pdata->type) {
	case M48T59RTC_TYPE_M48T59:
		name = "m48t59";
		ops = &m48t59_rtc_ops;
		pdata->offset = 0x1ff0;
		break;
	case M48T59RTC_TYPE_M48T02:
		name = "m48t02";
		ops = &m48t02_rtc_ops;
		pdata->offset = 0x7f0;
		break;
	case M48T59RTC_TYPE_M48T08:
		name = "m48t08";
		ops = &m48t02_rtc_ops;
		pdata->offset = 0x1ff0;
		break;
	default:
		dev_err(&pdev->dev, "Unknown RTC type\n");
		ret = -ENODEV;
		goto out;
	}

	m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE);
	if (IS_ERR(m48t59->rtc)) {
		ret = PTR_ERR(m48t59->rtc);
		goto out;
	}

	m48t59_nvram_attr.size = pdata->offset;

	ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
	if (ret)
		goto out;

	spin_lock_init(&m48t59->lock);
	platform_set_drvdata(pdev, m48t59);
	return 0;

out:
	if (!IS_ERR(m48t59->rtc))
		rtc_device_unregister(m48t59->rtc);
	if (m48t59->irq != NO_IRQ)
		free_irq(m48t59->irq, &pdev->dev);
	if (m48t59->ioaddr)
		iounmap(m48t59->ioaddr);
	if (m48t59)
		kfree(m48t59);
	return ret;
}

static int __devexit m48t59_rtc_remove(struct platform_device *pdev)
{
	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;

	sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
	if (!IS_ERR(m48t59->rtc))
		rtc_device_unregister(m48t59->rtc);
	if (m48t59->ioaddr && !pdata->ioaddr)
		iounmap(m48t59->ioaddr);
	if (m48t59->irq != NO_IRQ)
		free_irq(m48t59->irq, &pdev->dev);
	platform_set_drvdata(pdev, NULL);
	kfree(m48t59);
	return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:rtc-m48t59");

static struct platform_driver m48t59_rtc_driver = {
	.driver		= {
		.name	= "rtc-m48t59",
		.owner	= THIS_MODULE,
	},
	.probe		= m48t59_rtc_probe,
	.remove		= __devexit_p(m48t59_rtc_remove),
};

static int __init m48t59_rtc_init(void)
{
	return platform_driver_register(&m48t59_rtc_driver);
}

static void __exit m48t59_rtc_exit(void)
{
	platform_driver_unregister(&m48t59_rtc_driver);
}

module_init(m48t59_rtc_init);
module_exit(m48t59_rtc_exit);

MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
MODULE_LICENSE("GPL");