aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-mc13783.c
blob: 1379c7faa44803be830bd37a6b39b554dd8e0c03 (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
/*
 * Real Time Clock driver for Freescale MC13783 PMIC
 *
 * (C) 2009 Sascha Hauer, Pengutronix
 * (C) 2009 Uwe Kleine-Koenig, Pengutronix
 *
 * 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/mfd/mc13783.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtc.h>

#define DRIVER_NAME "mc13783-rtc"

#define MC13783_RTCTOD	20
#define MC13783_RTCTODA	21
#define MC13783_RTCDAY	22
#define MC13783_RTCDAYA	23

struct mc13783_rtc {
	struct rtc_device *rtc;
	struct mc13783 *mc13783;
	int valid;
};

static int mc13783_rtc_irq_enable_unlocked(struct device *dev,
		unsigned int enabled, int irq)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	int (*func)(struct mc13783 *mc13783, int irq);

	if (!priv->valid)
		return -ENODATA;

	func = enabled ? mc13783_irq_unmask : mc13783_irq_mask;
	return func(priv->mc13783, irq);
}

static int mc13783_rtc_irq_enable(struct device *dev,
		unsigned int enabled, int irq)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	int ret;

	mc13783_lock(priv->mc13783);

	ret = mc13783_rtc_irq_enable_unlocked(dev, enabled, irq);

	mc13783_unlock(priv->mc13783);

	return ret;
}

static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	unsigned int seconds, days1, days2;
	unsigned long s1970;
	int ret;

	mc13783_lock(priv->mc13783);

	if (!priv->valid) {
		ret = -ENODATA;
		goto out;
	}

	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days1);
	if (unlikely(ret))
		goto out;

	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTOD, &seconds);
	if (unlikely(ret))
		goto out;

	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days2);
out:
	mc13783_unlock(priv->mc13783);

	if (ret)
		return ret;

	if (days2 == days1 + 1) {
		if (seconds >= 86400 / 2)
			days2 = days1;
		else
			days1 = days2;
	}

	if (days1 != days2)
		return -EIO;

	s1970 = days1 * 86400 + seconds;

	rtc_time_to_tm(s1970, tm);

	return rtc_valid_tm(tm);
}

static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	unsigned int seconds, days;
	unsigned int alarmseconds;
	int ret;

	seconds = secs % 86400;
	days = secs / 86400;

	mc13783_lock(priv->mc13783);

	/*
	 * temporarily invalidate alarm to prevent triggering it when the day is
	 * already updated while the time isn't yet.
	 */
	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &alarmseconds);
	if (unlikely(ret))
		goto out;

	if (alarmseconds < 86400) {
		ret = mc13783_reg_write(priv->mc13783,
				MC13783_RTCTODA, 0x1ffff);
		if (unlikely(ret))
			goto out;
	}

	/*
	 * write seconds=0 to prevent a day switch between writing days
	 * and seconds below
	 */
	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0);
	if (unlikely(ret))
		goto out;

	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAY, days);
	if (unlikely(ret))
		goto out;

	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, seconds);
	if (unlikely(ret))
		goto out;

	/* restore alarm */
	if (alarmseconds < 86400) {
		ret = mc13783_reg_write(priv->mc13783,
				MC13783_RTCTODA, alarmseconds);
		if (unlikely(ret))
			goto out;
	}

	ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_RTCRST);
	if (unlikely(ret))
		goto out;

	ret = mc13783_irq_unmask(priv->mc13783, MC13783_IRQ_RTCRST);
out:
	priv->valid = !ret;

	mc13783_unlock(priv->mc13783);

	return ret;
}

static int mc13783_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	unsigned seconds, days;
	unsigned long s1970;
	int enabled, pending;
	int ret;

	mc13783_lock(priv->mc13783);

	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTODA, &seconds);
	if (unlikely(ret))
		goto out;
	if (seconds >= 86400) {
		ret = -ENODATA;
		goto out;
	}

	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days);
	if (unlikely(ret))
		goto out;

	ret = mc13783_irq_status(priv->mc13783, MC13783_IRQ_TODA,
			&enabled, &pending);

out:
	mc13783_unlock(priv->mc13783);

	if (ret)
		return ret;

	alarm->enabled = enabled;
	alarm->pending = pending;

	s1970 = days * 86400 + seconds;

	rtc_time_to_tm(s1970, &alarm->time);
	dev_dbg(dev, "%s: %lu\n", __func__, s1970);

	return 0;
}

static int mc13783_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct mc13783_rtc *priv = dev_get_drvdata(dev);
	unsigned long s1970;
	unsigned seconds, days;
	int ret;

	mc13783_lock(priv->mc13783);

	/* disable alarm to prevent false triggering */
	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, 0x1ffff);
	if (unlikely(ret))
		goto out;

	ret = mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TODA);
	if (unlikely(ret))
		goto out;

	ret = rtc_tm_to_time(&alarm->time, &s1970);
	if (unlikely(ret))
		goto out;

	dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
			s1970);

	ret = mc13783_rtc_irq_enable_unlocked(dev, alarm->enabled,
			MC13783_IRQ_TODA);
	if (unlikely(ret))
		goto out;

	seconds = s1970 % 86400;
	days = s1970 / 86400;

	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAYA, days);
	if (unlikely(ret))
		goto out;

	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTODA, seconds);

out:
	mc13783_unlock(priv->mc13783);

	return ret;
}

static irqreturn_t mc13783_rtc_alarm_handler(int irq, void *dev)
{
	struct mc13783_rtc *priv = dev;
	struct mc13783 *mc13783 = priv->mc13783;

	dev_dbg(&priv->rtc->dev, "Alarm\n");

	rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);

	mc13783_irq_ack(mc13783, irq);

	return IRQ_HANDLED;
}

static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev)
{
	struct mc13783_rtc *priv = dev;
	struct mc13783 *mc13783 = priv->mc13783;

	dev_dbg(&priv->rtc->dev, "1HZ\n");

	rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);

	mc13783_irq_ack(mc13783, irq);

	return IRQ_HANDLED;
}

static int mc13783_rtc_update_irq_enable(struct device *dev,
		unsigned int enabled)
{
	return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_1HZ);
}

static int mc13783_rtc_alarm_irq_enable(struct device *dev,
		unsigned int enabled)
{
	return mc13783_rtc_irq_enable(dev, enabled, MC13783_IRQ_TODA);
}

static const struct rtc_class_ops mc13783_rtc_ops = {
	.read_time = mc13783_rtc_read_time,
	.set_mmss = mc13783_rtc_set_mmss,
	.read_alarm = mc13783_rtc_read_alarm,
	.set_alarm = mc13783_rtc_set_alarm,
	.alarm_irq_enable = mc13783_rtc_alarm_irq_enable,
	.update_irq_enable = mc13783_rtc_update_irq_enable,
};

static irqreturn_t mc13783_rtc_reset_handler(int irq, void *dev)
{
	struct mc13783_rtc *priv = dev;
	struct mc13783 *mc13783 = priv->mc13783;

	dev_dbg(&priv->rtc->dev, "RTCRST\n");
	priv->valid = 0;

	mc13783_irq_mask(mc13783, irq);

	return IRQ_HANDLED;
}

static int __devinit mc13783_rtc_probe(struct platform_device *pdev)
{
	int ret;
	struct mc13783_rtc *priv;
	struct mc13783 *mc13783;
	int rtcrst_pending;

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

	mc13783 = dev_get_drvdata(pdev->dev.parent);
	priv->mc13783 = mc13783;

	platform_set_drvdata(pdev, priv);

	mc13783_lock(mc13783);

	ret = mc13783_irq_request(mc13783, MC13783_IRQ_RTCRST,
			mc13783_rtc_reset_handler, DRIVER_NAME, priv);
	if (ret)
		goto err_reset_irq_request;

	ret = mc13783_irq_status(mc13783, MC13783_IRQ_RTCRST,
			NULL, &rtcrst_pending);
	if (ret)
		goto err_reset_irq_status;

	priv->valid = !rtcrst_pending;

	ret = mc13783_irq_request_nounmask(mc13783, MC13783_IRQ_1HZ,
			mc13783_rtc_update_handler, DRIVER_NAME, priv);
	if (ret)
		goto err_update_irq_request;

	ret = mc13783_irq_request_nounmask(mc13783, MC13783_IRQ_TODA,
			mc13783_rtc_alarm_handler, DRIVER_NAME, priv);
	if (ret)
		goto err_alarm_irq_request;

	priv->rtc = rtc_device_register(pdev->name,
			&pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
	if (IS_ERR(priv->rtc)) {
		ret = PTR_ERR(priv->rtc);

		mc13783_irq_free(mc13783, MC13783_IRQ_TODA, priv);
err_alarm_irq_request:

		mc13783_irq_free(mc13783, MC13783_IRQ_1HZ, priv);
err_update_irq_request:

err_reset_irq_status:

		mc13783_irq_free(mc13783, MC13783_IRQ_RTCRST, priv);
err_reset_irq_request:

		platform_set_drvdata(pdev, NULL);
		kfree(priv);
	}

	mc13783_unlock(mc13783);

	return ret;
}

static int __devexit mc13783_rtc_remove(struct platform_device *pdev)
{
	struct mc13783_rtc *priv = platform_get_drvdata(pdev);

	mc13783_lock(priv->mc13783);

	rtc_device_unregister(priv->rtc);

	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TODA, priv);
	mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
	mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv);

	mc13783_unlock(priv->mc13783);

	platform_set_drvdata(pdev, NULL);

	kfree(priv);

	return 0;
}

static struct platform_driver mc13783_rtc_driver = {
	.remove = __devexit_p(mc13783_rtc_remove),
	.driver = {
		.name = DRIVER_NAME,
		.owner = THIS_MODULE,
	},
};

static int __init mc13783_rtc_init(void)
{
	return platform_driver_probe(&mc13783_rtc_driver, &mc13783_rtc_probe);
}
module_init(mc13783_rtc_init);

static void __exit mc13783_rtc_exit(void)
{
	platform_driver_unregister(&mc13783_rtc_driver);
}
module_exit(mc13783_rtc_exit);

MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("RTC driver for Freescale MC13783 PMIC");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);