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15#include <linux/slab.h>
16#include <linux/rtc.h>
17#include <linux/delay.h>
18#include <linux/mutex.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/mfd/max77686-private.h>
22#include <linux/irqdomain.h>
23#include <linux/regmap.h>
24
25
26#define BCD_EN_SHIFT 0
27#define BCD_EN_MASK (1 << BCD_EN_SHIFT)
28#define MODEL24_SHIFT 1
29#define MODEL24_MASK (1 << MODEL24_SHIFT)
30
31#define RTC_UDR_SHIFT 0
32#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
33#define RTC_RBUDR_SHIFT 4
34#define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT)
35
36#define WTSRT_SHIFT 0
37#define SMPLT_SHIFT 2
38#define WTSR_EN_SHIFT 6
39#define SMPL_EN_SHIFT 7
40#define WTSRT_MASK (3 << WTSRT_SHIFT)
41#define SMPLT_MASK (3 << SMPLT_SHIFT)
42#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT)
43#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT)
44
45#define HOUR_PM_SHIFT 6
46#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
47
48#define ALARM_ENABLE_SHIFT 7
49#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
50
51#define MAX77686_RTC_UPDATE_DELAY 16
52#undef MAX77686_RTC_WTSR_SMPL
53
54enum {
55 RTC_SEC = 0,
56 RTC_MIN,
57 RTC_HOUR,
58 RTC_WEEKDAY,
59 RTC_MONTH,
60 RTC_YEAR,
61 RTC_DATE,
62 RTC_NR_TIME
63};
64
65struct max77686_rtc_info {
66 struct device *dev;
67 struct max77686_dev *max77686;
68 struct i2c_client *rtc;
69 struct rtc_device *rtc_dev;
70 struct mutex lock;
71
72 struct regmap *regmap;
73
74 int virq;
75 int rtc_24hr_mode;
76};
77
78enum MAX77686_RTC_OP {
79 MAX77686_RTC_WRITE,
80 MAX77686_RTC_READ,
81};
82
83static inline int max77686_rtc_calculate_wday(u8 shifted)
84{
85 int counter = -1;
86 while (shifted) {
87 shifted >>= 1;
88 counter++;
89 }
90 return counter;
91}
92
93static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
94 int rtc_24hr_mode)
95{
96 tm->tm_sec = data[RTC_SEC] & 0x7f;
97 tm->tm_min = data[RTC_MIN] & 0x7f;
98 if (rtc_24hr_mode)
99 tm->tm_hour = data[RTC_HOUR] & 0x1f;
100 else {
101 tm->tm_hour = data[RTC_HOUR] & 0x0f;
102 if (data[RTC_HOUR] & HOUR_PM_MASK)
103 tm->tm_hour += 12;
104 }
105
106 tm->tm_wday = max77686_rtc_calculate_wday(data[RTC_WEEKDAY] & 0x7f);
107 tm->tm_mday = data[RTC_DATE] & 0x1f;
108 tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
109 tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
110 tm->tm_yday = 0;
111 tm->tm_isdst = 0;
112}
113
114static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
115{
116 data[RTC_SEC] = tm->tm_sec;
117 data[RTC_MIN] = tm->tm_min;
118 data[RTC_HOUR] = tm->tm_hour;
119 data[RTC_WEEKDAY] = 1 << tm->tm_wday;
120 data[RTC_DATE] = tm->tm_mday;
121 data[RTC_MONTH] = tm->tm_mon + 1;
122 data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
123
124 if (tm->tm_year < 100) {
125 pr_warn("%s: MAX77686 RTC cannot handle the year %d."
126 "Assume it's 2000.\n", __func__, 1900 + tm->tm_year);
127 return -EINVAL;
128 }
129 return 0;
130}
131
132static int max77686_rtc_update(struct max77686_rtc_info *info,
133 enum MAX77686_RTC_OP op)
134{
135 int ret;
136 unsigned int data;
137
138 if (op == MAX77686_RTC_WRITE)
139 data = 1 << RTC_UDR_SHIFT;
140 else
141 data = 1 << RTC_RBUDR_SHIFT;
142
143 ret = regmap_update_bits(info->max77686->rtc_regmap,
144 MAX77686_RTC_UPDATE0, data, data);
145 if (ret < 0)
146 dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
147 __func__, ret, data);
148 else {
149
150 msleep(MAX77686_RTC_UPDATE_DELAY);
151 }
152
153 return ret;
154}
155
156static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
157{
158 struct max77686_rtc_info *info = dev_get_drvdata(dev);
159 u8 data[RTC_NR_TIME];
160 int ret;
161
162 mutex_lock(&info->lock);
163
164 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
165 if (ret < 0)
166 goto out;
167
168 ret = regmap_bulk_read(info->max77686->rtc_regmap,
169 MAX77686_RTC_SEC, data, RTC_NR_TIME);
170 if (ret < 0) {
171 dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, ret);
172 goto out;
173 }
174
175 max77686_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
176
177 ret = rtc_valid_tm(tm);
178
179out:
180 mutex_unlock(&info->lock);
181 return ret;
182}
183
184static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
185{
186 struct max77686_rtc_info *info = dev_get_drvdata(dev);
187 u8 data[RTC_NR_TIME];
188 int ret;
189
190 ret = max77686_rtc_tm_to_data(tm, data);
191 if (ret < 0)
192 return ret;
193
194 mutex_lock(&info->lock);
195
196 ret = regmap_bulk_write(info->max77686->rtc_regmap,
197 MAX77686_RTC_SEC, data, RTC_NR_TIME);
198 if (ret < 0) {
199 dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
200 ret);
201 goto out;
202 }
203
204 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
205
206out:
207 mutex_unlock(&info->lock);
208 return ret;
209}
210
211static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
212{
213 struct max77686_rtc_info *info = dev_get_drvdata(dev);
214 u8 data[RTC_NR_TIME];
215 unsigned int val;
216 int i, ret;
217
218 mutex_lock(&info->lock);
219
220 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
221 if (ret < 0)
222 goto out;
223
224 ret = regmap_bulk_read(info->max77686->rtc_regmap,
225 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
226 if (ret < 0) {
227 dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
228 __func__, __LINE__, ret);
229 goto out;
230 }
231
232 max77686_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
233
234 alrm->enabled = 0;
235 for (i = 0; i < RTC_NR_TIME; i++) {
236 if (data[i] & ALARM_ENABLE_MASK) {
237 alrm->enabled = 1;
238 break;
239 }
240 }
241
242 alrm->pending = 0;
243 ret = regmap_read(info->max77686->regmap, MAX77686_REG_STATUS2, &val);
244 if (ret < 0) {
245 dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n",
246 __func__, __LINE__, ret);
247 goto out;
248 }
249
250 if (val & (1 << 4))
251 alrm->pending = 1;
252
253out:
254 mutex_unlock(&info->lock);
255 return 0;
256}
257
258static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
259{
260 u8 data[RTC_NR_TIME];
261 int ret, i;
262 struct rtc_time tm;
263
264 if (!mutex_is_locked(&info->lock))
265 dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
266
267 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
268 if (ret < 0)
269 goto out;
270
271 ret = regmap_bulk_read(info->max77686->rtc_regmap,
272 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
273 if (ret < 0) {
274 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
275 __func__, ret);
276 goto out;
277 }
278
279 max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
280
281 for (i = 0; i < RTC_NR_TIME; i++)
282 data[i] &= ~ALARM_ENABLE_MASK;
283
284 ret = regmap_bulk_write(info->max77686->rtc_regmap,
285 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
286 if (ret < 0) {
287 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
288 __func__, ret);
289 goto out;
290 }
291
292 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
293out:
294 return ret;
295}
296
297static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
298{
299 u8 data[RTC_NR_TIME];
300 int ret;
301 struct rtc_time tm;
302
303 if (!mutex_is_locked(&info->lock))
304 dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
305
306 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
307 if (ret < 0)
308 goto out;
309
310 ret = regmap_bulk_read(info->max77686->rtc_regmap,
311 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
312 if (ret < 0) {
313 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
314 __func__, ret);
315 goto out;
316 }
317
318 max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
319
320 data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
321 data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
322 data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
323 data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
324 if (data[RTC_MONTH] & 0xf)
325 data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
326 if (data[RTC_YEAR] & 0x7f)
327 data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
328 if (data[RTC_DATE] & 0x1f)
329 data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
330
331 ret = regmap_bulk_write(info->max77686->rtc_regmap,
332 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
333 if (ret < 0) {
334 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
335 __func__, ret);
336 goto out;
337 }
338
339 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
340out:
341 return ret;
342}
343
344static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
345{
346 struct max77686_rtc_info *info = dev_get_drvdata(dev);
347 u8 data[RTC_NR_TIME];
348 int ret;
349
350 ret = max77686_rtc_tm_to_data(&alrm->time, data);
351 if (ret < 0)
352 return ret;
353
354 mutex_lock(&info->lock);
355
356 ret = max77686_rtc_stop_alarm(info);
357 if (ret < 0)
358 goto out;
359
360 ret = regmap_bulk_write(info->max77686->rtc_regmap,
361 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
362
363 if (ret < 0) {
364 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
365 __func__, ret);
366 goto out;
367 }
368
369 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
370 if (ret < 0)
371 goto out;
372
373 if (alrm->enabled)
374 ret = max77686_rtc_start_alarm(info);
375out:
376 mutex_unlock(&info->lock);
377 return ret;
378}
379
380static int max77686_rtc_alarm_irq_enable(struct device *dev,
381 unsigned int enabled)
382{
383 struct max77686_rtc_info *info = dev_get_drvdata(dev);
384 int ret;
385
386 mutex_lock(&info->lock);
387 if (enabled)
388 ret = max77686_rtc_start_alarm(info);
389 else
390 ret = max77686_rtc_stop_alarm(info);
391 mutex_unlock(&info->lock);
392
393 return ret;
394}
395
396static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
397{
398 struct max77686_rtc_info *info = data;
399
400 dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
401
402 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
403
404 return IRQ_HANDLED;
405}
406
407static const struct rtc_class_ops max77686_rtc_ops = {
408 .read_time = max77686_rtc_read_time,
409 .set_time = max77686_rtc_set_time,
410 .read_alarm = max77686_rtc_read_alarm,
411 .set_alarm = max77686_rtc_set_alarm,
412 .alarm_irq_enable = max77686_rtc_alarm_irq_enable,
413};
414
415#ifdef MAX77686_RTC_WTSR_SMPL
416static void max77686_rtc_enable_wtsr(struct max77686_rtc_info *info, bool enable)
417{
418 int ret;
419 unsigned int val, mask;
420
421 if (enable)
422 val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
423 else
424 val = 0;
425
426 mask = WTSR_EN_MASK | WTSRT_MASK;
427
428 dev_info(info->dev, "%s: %s WTSR\n", __func__,
429 enable ? "enable" : "disable");
430
431 ret = regmap_update_bits(info->max77686->rtc_regmap,
432 MAX77686_WTSR_SMPL_CNTL, mask, val);
433 if (ret < 0) {
434 dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
435 __func__, ret);
436 return;
437 }
438
439 max77686_rtc_update(info, MAX77686_RTC_WRITE);
440}
441
442static void max77686_rtc_enable_smpl(struct max77686_rtc_info *info, bool enable)
443{
444 int ret;
445 unsigned int val, mask;
446
447 if (enable)
448 val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
449 else
450 val = 0;
451
452 mask = SMPL_EN_MASK | SMPLT_MASK;
453
454 dev_info(info->dev, "%s: %s SMPL\n", __func__,
455 enable ? "enable" : "disable");
456
457 ret = regmap_update_bits(info->max77686->rtc_regmap,
458 MAX77686_WTSR_SMPL_CNTL, mask, val);
459 if (ret < 0) {
460 dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
461 __func__, ret);
462 return;
463 }
464
465 max77686_rtc_update(info, MAX77686_RTC_WRITE);
466
467 val = 0;
468 regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
469 dev_info(info->dev, "%s: WTSR_SMPL(0x%02x)\n", __func__, val);
470}
471#endif
472
473static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
474{
475 u8 data[2];
476 int ret;
477
478
479 data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
480 data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
481
482 info->rtc_24hr_mode = 1;
483
484 ret = regmap_bulk_write(info->max77686->rtc_regmap, MAX77686_RTC_CONTROLM, data, 2);
485 if (ret < 0) {
486 dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
487 __func__, ret);
488 return ret;
489 }
490
491 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
492 return ret;
493}
494
495static struct regmap_config max77686_rtc_regmap_config = {
496 .reg_bits = 8,
497 .val_bits = 8,
498};
499
500static int max77686_rtc_probe(struct platform_device *pdev)
501{
502 struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
503 struct max77686_rtc_info *info;
504 int ret, virq;
505
506 dev_info(&pdev->dev, "%s\n", __func__);
507
508 info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
509 GFP_KERNEL);
510 if (!info)
511 return -ENOMEM;
512
513 mutex_init(&info->lock);
514 info->dev = &pdev->dev;
515 info->max77686 = max77686;
516 info->rtc = max77686->rtc;
517 info->max77686->rtc_regmap = devm_regmap_init_i2c(info->max77686->rtc,
518 &max77686_rtc_regmap_config);
519 if (IS_ERR(info->max77686->rtc_regmap)) {
520 ret = PTR_ERR(info->max77686->rtc_regmap);
521 dev_err(info->max77686->dev, "Failed to allocate register map: %d\n",
522 ret);
523 return ret;
524 }
525 platform_set_drvdata(pdev, info);
526
527 ret = max77686_rtc_init_reg(info);
528
529 if (ret < 0) {
530 dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
531 goto err_rtc;
532 }
533
534#ifdef MAX77686_RTC_WTSR_SMPL
535 max77686_rtc_enable_wtsr(info, true);
536 max77686_rtc_enable_smpl(info, true);
537#endif
538
539 device_init_wakeup(&pdev->dev, 1);
540
541 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77686-rtc",
542 &max77686_rtc_ops, THIS_MODULE);
543
544 if (IS_ERR(info->rtc_dev)) {
545 dev_info(&pdev->dev, "%s: fail\n", __func__);
546
547 ret = PTR_ERR(info->rtc_dev);
548 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
549 if (ret == 0)
550 ret = -EINVAL;
551 goto err_rtc;
552 }
553 virq = irq_create_mapping(max77686->irq_domain, MAX77686_RTCIRQ_RTCA1);
554 if (!virq) {
555 ret = -ENXIO;
556 goto err_rtc;
557 }
558 info->virq = virq;
559
560 ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
561 max77686_rtc_alarm_irq, 0, "rtc-alarm0", info);
562 if (ret < 0)
563 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
564 info->virq, ret);
565
566err_rtc:
567 return ret;
568}
569
570static void max77686_rtc_shutdown(struct platform_device *pdev)
571{
572#ifdef MAX77686_RTC_WTSR_SMPL
573 struct max77686_rtc_info *info = platform_get_drvdata(pdev);
574 int i;
575 u8 val = 0;
576
577 for (i = 0; i < 3; i++) {
578 max77686_rtc_enable_wtsr(info, false);
579 regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
580 dev_info(info->dev, "%s: WTSR_SMPL reg(0x%02x)\n", __func__,
581 val);
582 if (val & WTSR_EN_MASK) {
583 dev_emerg(info->dev, "%s: fail to disable WTSR\n",
584 __func__);
585 } else {
586 dev_info(info->dev, "%s: success to disable WTSR\n",
587 __func__);
588 break;
589 }
590 }
591
592
593 max77686_rtc_enable_smpl(info, false);
594#endif
595}
596
597static const struct platform_device_id rtc_id[] = {
598 { "max77686-rtc", 0 },
599 {},
600};
601
602static struct platform_driver max77686_rtc_driver = {
603 .driver = {
604 .name = "max77686-rtc",
605 .owner = THIS_MODULE,
606 },
607 .probe = max77686_rtc_probe,
608 .shutdown = max77686_rtc_shutdown,
609 .id_table = rtc_id,
610};
611
612module_platform_driver(max77686_rtc_driver);
613
614MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
615MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
616MODULE_LICENSE("GPL");
617
