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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2017 Spreadtrum Communications Inc.
4 *
5 */
6
7#include <linux/bitops.h>
8#include <linux/delay.h>
9#include <linux/err.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/regmap.h>
14#include <linux/rtc.h>
15
16#define SPRD_RTC_SEC_CNT_VALUE 0x0
17#define SPRD_RTC_MIN_CNT_VALUE 0x4
18#define SPRD_RTC_HOUR_CNT_VALUE 0x8
19#define SPRD_RTC_DAY_CNT_VALUE 0xc
20#define SPRD_RTC_SEC_CNT_UPD 0x10
21#define SPRD_RTC_MIN_CNT_UPD 0x14
22#define SPRD_RTC_HOUR_CNT_UPD 0x18
23#define SPRD_RTC_DAY_CNT_UPD 0x1c
24#define SPRD_RTC_SEC_ALM_UPD 0x20
25#define SPRD_RTC_MIN_ALM_UPD 0x24
26#define SPRD_RTC_HOUR_ALM_UPD 0x28
27#define SPRD_RTC_DAY_ALM_UPD 0x2c
28#define SPRD_RTC_INT_EN 0x30
29#define SPRD_RTC_INT_RAW_STS 0x34
30#define SPRD_RTC_INT_CLR 0x38
31#define SPRD_RTC_INT_MASK_STS 0x3C
32#define SPRD_RTC_SEC_ALM_VALUE 0x40
33#define SPRD_RTC_MIN_ALM_VALUE 0x44
34#define SPRD_RTC_HOUR_ALM_VALUE 0x48
35#define SPRD_RTC_DAY_ALM_VALUE 0x4c
36#define SPRD_RTC_SPG_VALUE 0x50
37#define SPRD_RTC_SPG_UPD 0x54
38#define SPRD_RTC_PWR_CTRL 0x58
39#define SPRD_RTC_PWR_STS 0x5c
40#define SPRD_RTC_SEC_AUXALM_UPD 0x60
41#define SPRD_RTC_MIN_AUXALM_UPD 0x64
42#define SPRD_RTC_HOUR_AUXALM_UPD 0x68
43#define SPRD_RTC_DAY_AUXALM_UPD 0x6c
44
45/* BIT & MASK definition for SPRD_RTC_INT_* registers */
46#define SPRD_RTC_SEC_EN BIT(0)
47#define SPRD_RTC_MIN_EN BIT(1)
48#define SPRD_RTC_HOUR_EN BIT(2)
49#define SPRD_RTC_DAY_EN BIT(3)
50#define SPRD_RTC_ALARM_EN BIT(4)
51#define SPRD_RTC_HRS_FORMAT_EN BIT(5)
52#define SPRD_RTC_AUXALM_EN BIT(6)
53#define SPRD_RTC_SPG_UPD_EN BIT(7)
54#define SPRD_RTC_SEC_UPD_EN BIT(8)
55#define SPRD_RTC_MIN_UPD_EN BIT(9)
56#define SPRD_RTC_HOUR_UPD_EN BIT(10)
57#define SPRD_RTC_DAY_UPD_EN BIT(11)
58#define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
59#define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
60#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
61#define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
62#define SPRD_RTC_INT_MASK GENMASK(15, 0)
63
64#define SPRD_RTC_TIME_INT_MASK \
65 (SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \
66 SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)
67
68#define SPRD_RTC_ALMTIME_INT_MASK \
69 (SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \
70 SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)
71
72#define SPRD_RTC_ALM_INT_MASK \
73 (SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \
74 SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \
75 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)
76
77/* second/minute/hour/day values mask definition */
78#define SPRD_RTC_SEC_MASK GENMASK(5, 0)
79#define SPRD_RTC_MIN_MASK GENMASK(5, 0)
80#define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
81#define SPRD_RTC_DAY_MASK GENMASK(15, 0)
82
83/* alarm lock definition for SPRD_RTC_SPG_UPD register */
84#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
85#define SPRD_RTC_ALM_UNLOCK 0xa5
86#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
87 SPRD_RTC_ALMLOCK_MASK)
88
89/* SPG values definition for SPRD_RTC_SPG_UPD register */
90#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
91
92/* power control/status definition */
93#define SPRD_RTC_POWER_RESET_VALUE 0x96
94#define SPRD_RTC_POWER_STS_CLEAR GENMASK(7, 0)
95#define SPRD_RTC_POWER_STS_SHIFT 8
96#define SPRD_RTC_POWER_STS_VALID \
97 (~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT)
98
99/* timeout of synchronizing time and alarm registers (us) */
100#define SPRD_RTC_POLL_TIMEOUT 200000
101#define SPRD_RTC_POLL_DELAY_US 20000
102
103struct sprd_rtc {
104 struct rtc_device *rtc;
105 struct regmap *regmap;
106 struct device *dev;
107 u32 base;
108 int irq;
109 bool valid;
110};
111
112/*
113 * The Spreadtrum RTC controller has 3 groups registers, including time, normal
114 * alarm and auxiliary alarm. The time group registers are used to set RTC time,
115 * the normal alarm registers are used to set normal alarm, and the auxiliary
116 * alarm registers are used to set auxiliary alarm. Both alarm event and
117 * auxiliary alarm event can wake up system from deep sleep, but only alarm
118 * event can power up system from power down status.
119 */
120enum sprd_rtc_reg_types {
121 SPRD_RTC_TIME,
122 SPRD_RTC_ALARM,
123 SPRD_RTC_AUX_ALARM,
124};
125
126static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
127{
128 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
129 SPRD_RTC_ALM_INT_MASK);
130}
131
132static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
133{
134 int ret;
135 u32 val;
136
137 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
138 if (ret)
139 return ret;
140
141 val &= ~SPRD_RTC_ALMLOCK_MASK;
142 if (lock)
143 val |= SPRD_RTC_ALM_LOCK;
144 else
145 val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;
146
147 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
148 if (ret)
149 return ret;
150
151 /* wait until the SPG value is updated successfully */
152 ret = regmap_read_poll_timeout(rtc->regmap,
153 rtc->base + SPRD_RTC_INT_RAW_STS, val,
154 (val & SPRD_RTC_SPG_UPD_EN),
155 SPRD_RTC_POLL_DELAY_US,
156 SPRD_RTC_POLL_TIMEOUT);
157 if (ret) {
158 dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
159 return ret;
160 }
161
162 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
163 SPRD_RTC_SPG_UPD_EN);
164}
165
166static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
167 time64_t *secs)
168{
169 u32 sec_reg, min_reg, hour_reg, day_reg;
170 u32 val, sec, min, hour, day;
171 int ret;
172
173 switch (type) {
174 case SPRD_RTC_TIME:
175 sec_reg = SPRD_RTC_SEC_CNT_VALUE;
176 min_reg = SPRD_RTC_MIN_CNT_VALUE;
177 hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
178 day_reg = SPRD_RTC_DAY_CNT_VALUE;
179 break;
180 case SPRD_RTC_ALARM:
181 sec_reg = SPRD_RTC_SEC_ALM_VALUE;
182 min_reg = SPRD_RTC_MIN_ALM_VALUE;
183 hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
184 day_reg = SPRD_RTC_DAY_ALM_VALUE;
185 break;
186 case SPRD_RTC_AUX_ALARM:
187 sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
188 min_reg = SPRD_RTC_MIN_AUXALM_UPD;
189 hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
190 day_reg = SPRD_RTC_DAY_AUXALM_UPD;
191 break;
192 default:
193 return -EINVAL;
194 }
195
196 ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
197 if (ret)
198 return ret;
199
200 sec = val & SPRD_RTC_SEC_MASK;
201
202 ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
203 if (ret)
204 return ret;
205
206 min = val & SPRD_RTC_MIN_MASK;
207
208 ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
209 if (ret)
210 return ret;
211
212 hour = val & SPRD_RTC_HOUR_MASK;
213
214 ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
215 if (ret)
216 return ret;
217
218 day = val & SPRD_RTC_DAY_MASK;
219 *secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
220 return 0;
221}
222
223static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
224 time64_t secs)
225{
226 u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
227 u32 sec, min, hour, day, val;
228 int ret, rem;
229
230 /* convert seconds to RTC time format */
231 day = div_s64_rem(secs, 86400, &rem);
232 hour = rem / 3600;
233 rem -= hour * 3600;
234 min = rem / 60;
235 sec = rem - min * 60;
236
237 switch (type) {
238 case SPRD_RTC_TIME:
239 sec_reg = SPRD_RTC_SEC_CNT_UPD;
240 min_reg = SPRD_RTC_MIN_CNT_UPD;
241 hour_reg = SPRD_RTC_HOUR_CNT_UPD;
242 day_reg = SPRD_RTC_DAY_CNT_UPD;
243 sts_mask = SPRD_RTC_TIME_INT_MASK;
244 break;
245 case SPRD_RTC_ALARM:
246 sec_reg = SPRD_RTC_SEC_ALM_UPD;
247 min_reg = SPRD_RTC_MIN_ALM_UPD;
248 hour_reg = SPRD_RTC_HOUR_ALM_UPD;
249 day_reg = SPRD_RTC_DAY_ALM_UPD;
250 sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
251 break;
252 case SPRD_RTC_AUX_ALARM:
253 sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
254 min_reg = SPRD_RTC_MIN_AUXALM_UPD;
255 hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
256 day_reg = SPRD_RTC_DAY_AUXALM_UPD;
257 sts_mask = 0;
258 break;
259 default:
260 return -EINVAL;
261 }
262
263 ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
264 if (ret)
265 return ret;
266
267 ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
268 if (ret)
269 return ret;
270
271 ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
272 if (ret)
273 return ret;
274
275 ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
276 if (ret)
277 return ret;
278
279 if (type == SPRD_RTC_AUX_ALARM)
280 return 0;
281
282 /*
283 * Since the time and normal alarm registers are put in always-power-on
284 * region supplied by VDDRTC, then these registers changing time will
285 * be very long, about 125ms. Thus here we should wait until all
286 * values are updated successfully.
287 */
288 ret = regmap_read_poll_timeout(rtc->regmap,
289 rtc->base + SPRD_RTC_INT_RAW_STS, val,
290 ((val & sts_mask) == sts_mask),
291 SPRD_RTC_POLL_DELAY_US,
292 SPRD_RTC_POLL_TIMEOUT);
293 if (ret < 0) {
294 dev_err(rtc->dev, "set time/alarm values timeout\n");
295 return ret;
296 }
297
298 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
299 sts_mask);
300}
301
302static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
303{
304 struct sprd_rtc *rtc = dev_get_drvdata(dev);
305 time64_t secs = rtc_tm_to_time64(&alrm->time);
306 int ret;
307
308 /* clear the auxiliary alarm interrupt status */
309 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
310 SPRD_RTC_AUXALM_EN);
311 if (ret)
312 return ret;
313
314 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
315 if (ret)
316 return ret;
317
318 if (alrm->enabled) {
319 ret = regmap_update_bits(rtc->regmap,
320 rtc->base + SPRD_RTC_INT_EN,
321 SPRD_RTC_AUXALM_EN,
322 SPRD_RTC_AUXALM_EN);
323 } else {
324 ret = regmap_update_bits(rtc->regmap,
325 rtc->base + SPRD_RTC_INT_EN,
326 SPRD_RTC_AUXALM_EN, 0);
327 }
328
329 return ret;
330}
331
332static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
333{
334 struct sprd_rtc *rtc = dev_get_drvdata(dev);
335 time64_t secs;
336 int ret;
337
338 if (!rtc->valid) {
339 dev_warn(dev, "RTC values are invalid\n");
340 return -EINVAL;
341 }
342
343 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
344 if (ret)
345 return ret;
346
347 rtc_time64_to_tm(secs, tm);
348 return 0;
349}
350
351static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
352{
353 struct sprd_rtc *rtc = dev_get_drvdata(dev);
354 time64_t secs = rtc_tm_to_time64(tm);
355 int ret;
356
357 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
358 if (ret)
359 return ret;
360
361 if (!rtc->valid) {
362 /* Clear RTC power status firstly */
363 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
364 SPRD_RTC_POWER_STS_CLEAR);
365 if (ret)
366 return ret;
367
368 /*
369 * Set RTC power status to indicate now RTC has valid time
370 * values.
371 */
372 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
373 SPRD_RTC_POWER_STS_VALID);
374 if (ret)
375 return ret;
376
377 rtc->valid = true;
378 }
379
380 return 0;
381}
382
383static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
384{
385 struct sprd_rtc *rtc = dev_get_drvdata(dev);
386 time64_t secs;
387 int ret;
388 u32 val;
389
390 /*
391 * The RTC core checks to see if there is an alarm already set in RTC
392 * hardware, and we always read the normal alarm at this time.
393 */
394 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
395 if (ret)
396 return ret;
397
398 rtc_time64_to_tm(secs, &alrm->time);
399
400 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
401 if (ret)
402 return ret;
403
404 alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
405
406 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
407 if (ret)
408 return ret;
409
410 alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
411 return 0;
412}
413
414static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
415{
416 struct sprd_rtc *rtc = dev_get_drvdata(dev);
417 time64_t secs = rtc_tm_to_time64(&alrm->time);
418 struct rtc_time aie_time =
419 rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
420 int ret;
421
422 /*
423 * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
424 * both normal alarm event and auxiliary alarm event can wake up system
425 * from deep sleep, but only alarm event can power up system from power
426 * down status. Moreover we do not need to poll about 125ms when
427 * updating auxiliary alarm registers. Thus we usually set auxiliary
428 * alarm when wake up system from deep sleep, and for other scenarios,
429 * we should set normal alarm with polling status.
430 *
431 * So here we check if the alarm time is set by aie_timer, if yes, we
432 * should set normal alarm, if not, we should set auxiliary alarm which
433 * means it is just a wake event.
434 */
435 if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
436 return sprd_rtc_set_aux_alarm(dev, alrm);
437
438 /* clear the alarm interrupt status firstly */
439 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
440 SPRD_RTC_ALARM_EN);
441 if (ret)
442 return ret;
443
444 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
445 if (ret)
446 return ret;
447
448 if (alrm->enabled) {
449 ret = regmap_update_bits(rtc->regmap,
450 rtc->base + SPRD_RTC_INT_EN,
451 SPRD_RTC_ALARM_EN,
452 SPRD_RTC_ALARM_EN);
453 if (ret)
454 return ret;
455
456 /* unlock the alarm to enable the alarm function. */
457 ret = sprd_rtc_lock_alarm(rtc, false);
458 } else {
459 regmap_update_bits(rtc->regmap,
460 rtc->base + SPRD_RTC_INT_EN,
461 SPRD_RTC_ALARM_EN, 0);
462
463 /*
464 * Lock the alarm function in case fake alarm event will power
465 * up systems.
466 */
467 ret = sprd_rtc_lock_alarm(rtc, true);
468 }
469
470 return ret;
471}
472
473static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
474{
475 struct sprd_rtc *rtc = dev_get_drvdata(dev);
476 int ret;
477
478 if (enabled) {
479 ret = regmap_update_bits(rtc->regmap,
480 rtc->base + SPRD_RTC_INT_EN,
481 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
482 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
483 if (ret)
484 return ret;
485
486 ret = sprd_rtc_lock_alarm(rtc, false);
487 } else {
488 regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
489 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
490
491 ret = sprd_rtc_lock_alarm(rtc, true);
492 }
493
494 return ret;
495}
496
497static const struct rtc_class_ops sprd_rtc_ops = {
498 .read_time = sprd_rtc_read_time,
499 .set_time = sprd_rtc_set_time,
500 .read_alarm = sprd_rtc_read_alarm,
501 .set_alarm = sprd_rtc_set_alarm,
502 .alarm_irq_enable = sprd_rtc_alarm_irq_enable,
503};
504
505static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
506{
507 struct sprd_rtc *rtc = dev_id;
508 int ret;
509
510 ret = sprd_rtc_clear_alarm_ints(rtc);
511 if (ret)
512 return IRQ_RETVAL(ret);
513
514 rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
515 return IRQ_HANDLED;
516}
517
518static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
519{
520 u32 val;
521 int ret;
522
523 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
524 if (ret)
525 return ret;
526
527 /*
528 * If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
529 * means the RTC has been powered down, so the RTC time values are
530 * invalid.
531 */
532 rtc->valid = val != SPRD_RTC_POWER_RESET_VALUE;
533 return 0;
534}
535
536static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc)
537{
538 u32 val;
539 int ret;
540
541 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
542 if (ret)
543 return ret;
544
545 /*
546 * The SPRD_RTC_INT_EN register is not put in always-power-on region
547 * supplied by VDDRTC, so we should check if we need enable the alarm
548 * interrupt when system booting.
549 *
550 * If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in
551 * always-power-on region, that means we have set one alarm last time,
552 * so we should enable the alarm interrupt to help RTC core to see if
553 * there is an alarm already set in RTC hardware.
554 */
555 if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG))
556 return 0;
557
558 return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
559 SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN);
560}
561
562static int sprd_rtc_probe(struct platform_device *pdev)
563{
564 struct device_node *node = pdev->dev.of_node;
565 struct sprd_rtc *rtc;
566 int ret;
567
568 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
569 if (!rtc)
570 return -ENOMEM;
571
572 rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
573 if (!rtc->regmap)
574 return -ENODEV;
575
576 ret = of_property_read_u32(node, "reg", &rtc->base);
577 if (ret) {
578 dev_err(&pdev->dev, "failed to get RTC base address\n");
579 return ret;
580 }
581
582 rtc->irq = platform_get_irq(pdev, 0);
583 if (rtc->irq < 0)
584 return rtc->irq;
585
586 rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
587 if (IS_ERR(rtc->rtc))
588 return PTR_ERR(rtc->rtc);
589
590 rtc->dev = &pdev->dev;
591 platform_set_drvdata(pdev, rtc);
592
593 /* check if we need set the alarm interrupt */
594 ret = sprd_rtc_check_alarm_int(rtc);
595 if (ret) {
596 dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n");
597 return ret;
598 }
599
600 /* check if RTC time values are valid */
601 ret = sprd_rtc_check_power_down(rtc);
602 if (ret) {
603 dev_err(&pdev->dev, "failed to check RTC time values\n");
604 return ret;
605 }
606
607 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
608 sprd_rtc_handler,
609 IRQF_ONESHOT | IRQF_EARLY_RESUME,
610 pdev->name, rtc);
611 if (ret < 0) {
612 dev_err(&pdev->dev, "failed to request RTC irq\n");
613 return ret;
614 }
615
616 device_init_wakeup(&pdev->dev, 1);
617
618 rtc->rtc->ops = &sprd_rtc_ops;
619 rtc->rtc->range_min = 0;
620 rtc->rtc->range_max = 5662310399LL;
621 ret = devm_rtc_register_device(rtc->rtc);
622 if (ret) {
623 device_init_wakeup(&pdev->dev, 0);
624 return ret;
625 }
626
627 return 0;
628}
629
630static const struct of_device_id sprd_rtc_of_match[] = {
631 { .compatible = "sprd,sc2731-rtc", },
632 { },
633};
634MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
635
636static struct platform_driver sprd_rtc_driver = {
637 .driver = {
638 .name = "sprd-rtc",
639 .of_match_table = sprd_rtc_of_match,
640 },
641 .probe = sprd_rtc_probe,
642};
643module_platform_driver(sprd_rtc_driver);
644
645MODULE_LICENSE("GPL v2");
646MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
647MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
1/*
2 * Copyright (C) 2017 Spreadtrum Communications Inc.
3 *
4 * SPDX-License-Identifier: GPL-2.0
5 */
6
7#include <linux/bitops.h>
8#include <linux/delay.h>
9#include <linux/err.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/regmap.h>
14#include <linux/rtc.h>
15
16#define SPRD_RTC_SEC_CNT_VALUE 0x0
17#define SPRD_RTC_MIN_CNT_VALUE 0x4
18#define SPRD_RTC_HOUR_CNT_VALUE 0x8
19#define SPRD_RTC_DAY_CNT_VALUE 0xc
20#define SPRD_RTC_SEC_CNT_UPD 0x10
21#define SPRD_RTC_MIN_CNT_UPD 0x14
22#define SPRD_RTC_HOUR_CNT_UPD 0x18
23#define SPRD_RTC_DAY_CNT_UPD 0x1c
24#define SPRD_RTC_SEC_ALM_UPD 0x20
25#define SPRD_RTC_MIN_ALM_UPD 0x24
26#define SPRD_RTC_HOUR_ALM_UPD 0x28
27#define SPRD_RTC_DAY_ALM_UPD 0x2c
28#define SPRD_RTC_INT_EN 0x30
29#define SPRD_RTC_INT_RAW_STS 0x34
30#define SPRD_RTC_INT_CLR 0x38
31#define SPRD_RTC_INT_MASK_STS 0x3C
32#define SPRD_RTC_SEC_ALM_VALUE 0x40
33#define SPRD_RTC_MIN_ALM_VALUE 0x44
34#define SPRD_RTC_HOUR_ALM_VALUE 0x48
35#define SPRD_RTC_DAY_ALM_VALUE 0x4c
36#define SPRD_RTC_SPG_VALUE 0x50
37#define SPRD_RTC_SPG_UPD 0x54
38#define SPRD_RTC_SEC_AUXALM_UPD 0x60
39#define SPRD_RTC_MIN_AUXALM_UPD 0x64
40#define SPRD_RTC_HOUR_AUXALM_UPD 0x68
41#define SPRD_RTC_DAY_AUXALM_UPD 0x6c
42
43/* BIT & MASK definition for SPRD_RTC_INT_* registers */
44#define SPRD_RTC_SEC_EN BIT(0)
45#define SPRD_RTC_MIN_EN BIT(1)
46#define SPRD_RTC_HOUR_EN BIT(2)
47#define SPRD_RTC_DAY_EN BIT(3)
48#define SPRD_RTC_ALARM_EN BIT(4)
49#define SPRD_RTC_HRS_FORMAT_EN BIT(5)
50#define SPRD_RTC_AUXALM_EN BIT(6)
51#define SPRD_RTC_SPG_UPD_EN BIT(7)
52#define SPRD_RTC_SEC_UPD_EN BIT(8)
53#define SPRD_RTC_MIN_UPD_EN BIT(9)
54#define SPRD_RTC_HOUR_UPD_EN BIT(10)
55#define SPRD_RTC_DAY_UPD_EN BIT(11)
56#define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
57#define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
58#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
59#define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
60#define SPRD_RTC_INT_MASK GENMASK(15, 0)
61
62#define SPRD_RTC_TIME_INT_MASK \
63 (SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \
64 SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)
65
66#define SPRD_RTC_ALMTIME_INT_MASK \
67 (SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \
68 SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)
69
70#define SPRD_RTC_ALM_INT_MASK \
71 (SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \
72 SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \
73 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)
74
75/* second/minute/hour/day values mask definition */
76#define SPRD_RTC_SEC_MASK GENMASK(5, 0)
77#define SPRD_RTC_MIN_MASK GENMASK(5, 0)
78#define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
79#define SPRD_RTC_DAY_MASK GENMASK(15, 0)
80
81/* alarm lock definition for SPRD_RTC_SPG_UPD register */
82#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
83#define SPRD_RTC_ALM_UNLOCK 0xa5
84#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
85 SPRD_RTC_ALMLOCK_MASK)
86
87/* SPG values definition for SPRD_RTC_SPG_UPD register */
88#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
89#define SPRD_RTC_POWER_RESET_FLAG BIT(9)
90
91/* timeout of synchronizing time and alarm registers (us) */
92#define SPRD_RTC_POLL_TIMEOUT 200000
93#define SPRD_RTC_POLL_DELAY_US 20000
94
95struct sprd_rtc {
96 struct rtc_device *rtc;
97 struct regmap *regmap;
98 struct device *dev;
99 u32 base;
100 int irq;
101 bool valid;
102};
103
104/*
105 * The Spreadtrum RTC controller has 3 groups registers, including time, normal
106 * alarm and auxiliary alarm. The time group registers are used to set RTC time,
107 * the normal alarm registers are used to set normal alarm, and the auxiliary
108 * alarm registers are used to set auxiliary alarm. Both alarm event and
109 * auxiliary alarm event can wake up system from deep sleep, but only alarm
110 * event can power up system from power down status.
111 */
112enum sprd_rtc_reg_types {
113 SPRD_RTC_TIME,
114 SPRD_RTC_ALARM,
115 SPRD_RTC_AUX_ALARM,
116};
117
118static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
119{
120 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
121 SPRD_RTC_ALM_INT_MASK);
122}
123
124static int sprd_rtc_disable_ints(struct sprd_rtc *rtc)
125{
126 int ret;
127
128 ret = regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
129 SPRD_RTC_INT_MASK, 0);
130 if (ret)
131 return ret;
132
133 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
134 SPRD_RTC_INT_MASK);
135}
136
137static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
138{
139 int ret;
140 u32 val;
141
142 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
143 if (ret)
144 return ret;
145
146 val &= ~(SPRD_RTC_ALMLOCK_MASK | SPRD_RTC_POWEROFF_ALM_FLAG);
147 if (lock)
148 val |= SPRD_RTC_ALM_LOCK;
149 else
150 val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;
151
152 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
153 if (ret)
154 return ret;
155
156 /* wait until the SPG value is updated successfully */
157 ret = regmap_read_poll_timeout(rtc->regmap,
158 rtc->base + SPRD_RTC_INT_RAW_STS, val,
159 (val & SPRD_RTC_SPG_UPD_EN),
160 SPRD_RTC_POLL_DELAY_US,
161 SPRD_RTC_POLL_TIMEOUT);
162 if (ret) {
163 dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
164 return ret;
165 }
166
167 return 0;
168}
169
170static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
171 time64_t *secs)
172{
173 u32 sec_reg, min_reg, hour_reg, day_reg;
174 u32 val, sec, min, hour, day;
175 int ret;
176
177 switch (type) {
178 case SPRD_RTC_TIME:
179 sec_reg = SPRD_RTC_SEC_CNT_VALUE;
180 min_reg = SPRD_RTC_MIN_CNT_VALUE;
181 hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
182 day_reg = SPRD_RTC_DAY_CNT_VALUE;
183 break;
184 case SPRD_RTC_ALARM:
185 sec_reg = SPRD_RTC_SEC_ALM_VALUE;
186 min_reg = SPRD_RTC_MIN_ALM_VALUE;
187 hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
188 day_reg = SPRD_RTC_DAY_ALM_VALUE;
189 break;
190 case SPRD_RTC_AUX_ALARM:
191 sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
192 min_reg = SPRD_RTC_MIN_AUXALM_UPD;
193 hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
194 day_reg = SPRD_RTC_DAY_AUXALM_UPD;
195 break;
196 default:
197 return -EINVAL;
198 }
199
200 ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
201 if (ret)
202 return ret;
203
204 sec = val & SPRD_RTC_SEC_MASK;
205
206 ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
207 if (ret)
208 return ret;
209
210 min = val & SPRD_RTC_MIN_MASK;
211
212 ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
213 if (ret)
214 return ret;
215
216 hour = val & SPRD_RTC_HOUR_MASK;
217
218 ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
219 if (ret)
220 return ret;
221
222 day = val & SPRD_RTC_DAY_MASK;
223 *secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
224 return 0;
225}
226
227static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
228 time64_t secs)
229{
230 u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
231 u32 sec, min, hour, day, val;
232 int ret, rem;
233
234 /* convert seconds to RTC time format */
235 day = div_s64_rem(secs, 86400, &rem);
236 hour = rem / 3600;
237 rem -= hour * 3600;
238 min = rem / 60;
239 sec = rem - min * 60;
240
241 switch (type) {
242 case SPRD_RTC_TIME:
243 sec_reg = SPRD_RTC_SEC_CNT_UPD;
244 min_reg = SPRD_RTC_MIN_CNT_UPD;
245 hour_reg = SPRD_RTC_HOUR_CNT_UPD;
246 day_reg = SPRD_RTC_DAY_CNT_UPD;
247 sts_mask = SPRD_RTC_TIME_INT_MASK;
248 break;
249 case SPRD_RTC_ALARM:
250 sec_reg = SPRD_RTC_SEC_ALM_UPD;
251 min_reg = SPRD_RTC_MIN_ALM_UPD;
252 hour_reg = SPRD_RTC_HOUR_ALM_UPD;
253 day_reg = SPRD_RTC_DAY_ALM_UPD;
254 sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
255 break;
256 case SPRD_RTC_AUX_ALARM:
257 sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
258 min_reg = SPRD_RTC_MIN_AUXALM_UPD;
259 hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
260 day_reg = SPRD_RTC_DAY_AUXALM_UPD;
261 sts_mask = 0;
262 break;
263 default:
264 return -EINVAL;
265 }
266
267 ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
268 if (ret)
269 return ret;
270
271 ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
272 if (ret)
273 return ret;
274
275 ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
276 if (ret)
277 return ret;
278
279 ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
280 if (ret)
281 return ret;
282
283 if (type == SPRD_RTC_AUX_ALARM)
284 return 0;
285
286 /*
287 * Since the time and normal alarm registers are put in always-power-on
288 * region supplied by VDDRTC, then these registers changing time will
289 * be very long, about 125ms. Thus here we should wait until all
290 * values are updated successfully.
291 */
292 ret = regmap_read_poll_timeout(rtc->regmap,
293 rtc->base + SPRD_RTC_INT_RAW_STS, val,
294 ((val & sts_mask) == sts_mask),
295 SPRD_RTC_POLL_DELAY_US,
296 SPRD_RTC_POLL_TIMEOUT);
297 if (ret < 0) {
298 dev_err(rtc->dev, "set time/alarm values timeout\n");
299 return ret;
300 }
301
302 return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
303 sts_mask);
304}
305
306static int sprd_rtc_read_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
307{
308 struct sprd_rtc *rtc = dev_get_drvdata(dev);
309 time64_t secs;
310 u32 val;
311 int ret;
312
313 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
314 if (ret)
315 return ret;
316
317 rtc_time64_to_tm(secs, &alrm->time);
318
319 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
320 if (ret)
321 return ret;
322
323 alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);
324
325 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
326 if (ret)
327 return ret;
328
329 alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
330 return 0;
331}
332
333static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
334{
335 struct sprd_rtc *rtc = dev_get_drvdata(dev);
336 time64_t secs = rtc_tm_to_time64(&alrm->time);
337 int ret;
338
339 /* clear the auxiliary alarm interrupt status */
340 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
341 SPRD_RTC_AUXALM_EN);
342 if (ret)
343 return ret;
344
345 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
346 if (ret)
347 return ret;
348
349 if (alrm->enabled) {
350 ret = regmap_update_bits(rtc->regmap,
351 rtc->base + SPRD_RTC_INT_EN,
352 SPRD_RTC_AUXALM_EN,
353 SPRD_RTC_AUXALM_EN);
354 } else {
355 ret = regmap_update_bits(rtc->regmap,
356 rtc->base + SPRD_RTC_INT_EN,
357 SPRD_RTC_AUXALM_EN, 0);
358 }
359
360 return ret;
361}
362
363static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
364{
365 struct sprd_rtc *rtc = dev_get_drvdata(dev);
366 time64_t secs;
367 int ret;
368
369 if (!rtc->valid) {
370 dev_warn(dev, "RTC values are invalid\n");
371 return -EINVAL;
372 }
373
374 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
375 if (ret)
376 return ret;
377
378 rtc_time64_to_tm(secs, tm);
379 return 0;
380}
381
382static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
383{
384 struct sprd_rtc *rtc = dev_get_drvdata(dev);
385 time64_t secs = rtc_tm_to_time64(tm);
386 u32 val;
387 int ret;
388
389 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
390 if (ret)
391 return ret;
392
393 if (!rtc->valid) {
394 /*
395 * Set SPRD_RTC_POWER_RESET_FLAG to indicate now RTC has valid
396 * time values.
397 */
398 ret = regmap_update_bits(rtc->regmap,
399 rtc->base + SPRD_RTC_SPG_UPD,
400 SPRD_RTC_POWER_RESET_FLAG,
401 SPRD_RTC_POWER_RESET_FLAG);
402 if (ret)
403 return ret;
404
405 ret = regmap_read_poll_timeout(rtc->regmap,
406 rtc->base + SPRD_RTC_INT_RAW_STS,
407 val, (val & SPRD_RTC_SPG_UPD_EN),
408 SPRD_RTC_POLL_DELAY_US,
409 SPRD_RTC_POLL_TIMEOUT);
410 if (ret) {
411 dev_err(rtc->dev, "failed to update SPG value:%d\n",
412 ret);
413 return ret;
414 }
415
416 rtc->valid = true;
417 }
418
419 return 0;
420}
421
422static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
423{
424 struct sprd_rtc *rtc = dev_get_drvdata(dev);
425 time64_t secs;
426 int ret;
427 u32 val;
428
429 /*
430 * If aie_timer is enabled, we should get the normal alarm time.
431 * Otherwise we should get auxiliary alarm time.
432 */
433 if (rtc->rtc && rtc->rtc->aie_timer.enabled == 0)
434 return sprd_rtc_read_aux_alarm(dev, alrm);
435
436 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
437 if (ret)
438 return ret;
439
440 rtc_time64_to_tm(secs, &alrm->time);
441
442 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
443 if (ret)
444 return ret;
445
446 alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
447
448 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
449 if (ret)
450 return ret;
451
452 alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
453 return 0;
454}
455
456static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
457{
458 struct sprd_rtc *rtc = dev_get_drvdata(dev);
459 time64_t secs = rtc_tm_to_time64(&alrm->time);
460 struct rtc_time aie_time =
461 rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
462 int ret;
463
464 /*
465 * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
466 * both normal alarm event and auxiliary alarm event can wake up system
467 * from deep sleep, but only alarm event can power up system from power
468 * down status. Moreover we do not need to poll about 125ms when
469 * updating auxiliary alarm registers. Thus we usually set auxiliary
470 * alarm when wake up system from deep sleep, and for other scenarios,
471 * we should set normal alarm with polling status.
472 *
473 * So here we check if the alarm time is set by aie_timer, if yes, we
474 * should set normal alarm, if not, we should set auxiliary alarm which
475 * means it is just a wake event.
476 */
477 if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
478 return sprd_rtc_set_aux_alarm(dev, alrm);
479
480 /* clear the alarm interrupt status firstly */
481 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
482 SPRD_RTC_ALARM_EN);
483 if (ret)
484 return ret;
485
486 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
487 if (ret)
488 return ret;
489
490 if (alrm->enabled) {
491 ret = regmap_update_bits(rtc->regmap,
492 rtc->base + SPRD_RTC_INT_EN,
493 SPRD_RTC_ALARM_EN,
494 SPRD_RTC_ALARM_EN);
495 if (ret)
496 return ret;
497
498 /* unlock the alarm to enable the alarm function. */
499 ret = sprd_rtc_lock_alarm(rtc, false);
500 } else {
501 regmap_update_bits(rtc->regmap,
502 rtc->base + SPRD_RTC_INT_EN,
503 SPRD_RTC_ALARM_EN, 0);
504
505 /*
506 * Lock the alarm function in case fake alarm event will power
507 * up systems.
508 */
509 ret = sprd_rtc_lock_alarm(rtc, true);
510 }
511
512 return ret;
513}
514
515static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
516{
517 struct sprd_rtc *rtc = dev_get_drvdata(dev);
518 int ret;
519
520 if (enabled) {
521 ret = regmap_update_bits(rtc->regmap,
522 rtc->base + SPRD_RTC_INT_EN,
523 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
524 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
525 if (ret)
526 return ret;
527
528 ret = sprd_rtc_lock_alarm(rtc, false);
529 } else {
530 regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
531 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
532
533 ret = sprd_rtc_lock_alarm(rtc, true);
534 }
535
536 return ret;
537}
538
539static const struct rtc_class_ops sprd_rtc_ops = {
540 .read_time = sprd_rtc_read_time,
541 .set_time = sprd_rtc_set_time,
542 .read_alarm = sprd_rtc_read_alarm,
543 .set_alarm = sprd_rtc_set_alarm,
544 .alarm_irq_enable = sprd_rtc_alarm_irq_enable,
545};
546
547static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
548{
549 struct sprd_rtc *rtc = dev_id;
550 int ret;
551
552 ret = sprd_rtc_clear_alarm_ints(rtc);
553 if (ret)
554 return IRQ_RETVAL(ret);
555
556 rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
557 return IRQ_HANDLED;
558}
559
560static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
561{
562 u32 val;
563 int ret;
564
565 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
566 if (ret)
567 return ret;
568
569 /*
570 * If the SPRD_RTC_POWER_RESET_FLAG was not set, which means the RTC has
571 * been powered down, so the RTC time values are invalid.
572 */
573 rtc->valid = (val & SPRD_RTC_POWER_RESET_FLAG) ? true : false;
574 return 0;
575}
576
577static int sprd_rtc_probe(struct platform_device *pdev)
578{
579 struct device_node *node = pdev->dev.of_node;
580 struct sprd_rtc *rtc;
581 int ret;
582
583 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
584 if (!rtc)
585 return -ENOMEM;
586
587 rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
588 if (!rtc->regmap)
589 return -ENODEV;
590
591 ret = of_property_read_u32(node, "reg", &rtc->base);
592 if (ret) {
593 dev_err(&pdev->dev, "failed to get RTC base address\n");
594 return ret;
595 }
596
597 rtc->irq = platform_get_irq(pdev, 0);
598 if (rtc->irq < 0) {
599 dev_err(&pdev->dev, "failed to get RTC irq number\n");
600 return rtc->irq;
601 }
602
603 rtc->dev = &pdev->dev;
604 platform_set_drvdata(pdev, rtc);
605
606 /* clear all RTC interrupts and disable all RTC interrupts */
607 ret = sprd_rtc_disable_ints(rtc);
608 if (ret) {
609 dev_err(&pdev->dev, "failed to disable RTC interrupts\n");
610 return ret;
611 }
612
613 /* check if RTC time values are valid */
614 ret = sprd_rtc_check_power_down(rtc);
615 if (ret) {
616 dev_err(&pdev->dev, "failed to check RTC time values\n");
617 return ret;
618 }
619
620 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
621 sprd_rtc_handler,
622 IRQF_ONESHOT | IRQF_EARLY_RESUME,
623 pdev->name, rtc);
624 if (ret < 0) {
625 dev_err(&pdev->dev, "failed to request RTC irq\n");
626 return ret;
627 }
628
629 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
630 &sprd_rtc_ops, THIS_MODULE);
631 if (IS_ERR(rtc->rtc))
632 return PTR_ERR(rtc->rtc);
633
634 device_init_wakeup(&pdev->dev, 1);
635 return 0;
636}
637
638static int sprd_rtc_remove(struct platform_device *pdev)
639{
640 device_init_wakeup(&pdev->dev, 0);
641 return 0;
642}
643
644static const struct of_device_id sprd_rtc_of_match[] = {
645 { .compatible = "sprd,sc2731-rtc", },
646 { },
647};
648MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
649
650static struct platform_driver sprd_rtc_driver = {
651 .driver = {
652 .name = "sprd-rtc",
653 .of_match_table = sprd_rtc_of_match,
654 },
655 .probe = sprd_rtc_probe,
656 .remove = sprd_rtc_remove,
657};
658module_platform_driver(sprd_rtc_driver);
659
660MODULE_LICENSE("GPL v2");
661MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
662MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");