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_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
103 struct 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 */
120 enum sprd_rtc_reg_types {
121 SPRD_RTC_TIME,
122 SPRD_RTC_ALARM,
123 SPRD_RTC_AUX_ALARM,
124 };
125
sprd_rtc_clear_alarm_ints(struct sprd_rtc * rtc)126 static 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
sprd_rtc_lock_alarm(struct sprd_rtc * rtc,bool lock)132 static 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
sprd_rtc_get_secs(struct sprd_rtc * rtc,enum sprd_rtc_reg_types type,time64_t * secs)166 static 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
sprd_rtc_set_secs(struct sprd_rtc * rtc,enum sprd_rtc_reg_types type,time64_t secs)223 static 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
sprd_rtc_read_aux_alarm(struct device * dev,struct rtc_wkalrm * alrm)302 static int sprd_rtc_read_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
303 {
304 struct sprd_rtc *rtc = dev_get_drvdata(dev);
305 time64_t secs;
306 u32 val;
307 int ret;
308
309 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
310 if (ret)
311 return ret;
312
313 rtc_time64_to_tm(secs, &alrm->time);
314
315 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
316 if (ret)
317 return ret;
318
319 alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);
320
321 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
322 if (ret)
323 return ret;
324
325 alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
326 return 0;
327 }
328
sprd_rtc_set_aux_alarm(struct device * dev,struct rtc_wkalrm * alrm)329 static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
330 {
331 struct sprd_rtc *rtc = dev_get_drvdata(dev);
332 time64_t secs = rtc_tm_to_time64(&alrm->time);
333 int ret;
334
335 /* clear the auxiliary alarm interrupt status */
336 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
337 SPRD_RTC_AUXALM_EN);
338 if (ret)
339 return ret;
340
341 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
342 if (ret)
343 return ret;
344
345 if (alrm->enabled) {
346 ret = regmap_update_bits(rtc->regmap,
347 rtc->base + SPRD_RTC_INT_EN,
348 SPRD_RTC_AUXALM_EN,
349 SPRD_RTC_AUXALM_EN);
350 } else {
351 ret = regmap_update_bits(rtc->regmap,
352 rtc->base + SPRD_RTC_INT_EN,
353 SPRD_RTC_AUXALM_EN, 0);
354 }
355
356 return ret;
357 }
358
sprd_rtc_read_time(struct device * dev,struct rtc_time * tm)359 static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
360 {
361 struct sprd_rtc *rtc = dev_get_drvdata(dev);
362 time64_t secs;
363 int ret;
364
365 if (!rtc->valid) {
366 dev_warn(dev, "RTC values are invalid\n");
367 return -EINVAL;
368 }
369
370 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
371 if (ret)
372 return ret;
373
374 rtc_time64_to_tm(secs, tm);
375 return 0;
376 }
377
sprd_rtc_set_time(struct device * dev,struct rtc_time * tm)378 static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
379 {
380 struct sprd_rtc *rtc = dev_get_drvdata(dev);
381 time64_t secs = rtc_tm_to_time64(tm);
382 int ret;
383
384 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
385 if (ret)
386 return ret;
387
388 if (!rtc->valid) {
389 /* Clear RTC power status firstly */
390 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
391 SPRD_RTC_POWER_STS_CLEAR);
392 if (ret)
393 return ret;
394
395 /*
396 * Set RTC power status to indicate now RTC has valid time
397 * values.
398 */
399 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
400 SPRD_RTC_POWER_STS_VALID);
401 if (ret)
402 return ret;
403
404 rtc->valid = true;
405 }
406
407 return 0;
408 }
409
sprd_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)410 static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
411 {
412 struct sprd_rtc *rtc = dev_get_drvdata(dev);
413 time64_t secs;
414 int ret;
415 u32 val;
416
417 /*
418 * Before RTC device is registered, it will check to see if there is an
419 * alarm already set in RTC hardware, and we always read the normal
420 * alarm at this time.
421 *
422 * Or if aie_timer is enabled, we should get the normal alarm time.
423 * Otherwise we should get auxiliary alarm time.
424 */
425 if (rtc->rtc && rtc->rtc->registered && rtc->rtc->aie_timer.enabled == 0)
426 return sprd_rtc_read_aux_alarm(dev, alrm);
427
428 ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
429 if (ret)
430 return ret;
431
432 rtc_time64_to_tm(secs, &alrm->time);
433
434 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
435 if (ret)
436 return ret;
437
438 alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
439
440 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
441 if (ret)
442 return ret;
443
444 alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
445 return 0;
446 }
447
sprd_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)448 static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
449 {
450 struct sprd_rtc *rtc = dev_get_drvdata(dev);
451 time64_t secs = rtc_tm_to_time64(&alrm->time);
452 struct rtc_time aie_time =
453 rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
454 int ret;
455
456 /*
457 * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
458 * both normal alarm event and auxiliary alarm event can wake up system
459 * from deep sleep, but only alarm event can power up system from power
460 * down status. Moreover we do not need to poll about 125ms when
461 * updating auxiliary alarm registers. Thus we usually set auxiliary
462 * alarm when wake up system from deep sleep, and for other scenarios,
463 * we should set normal alarm with polling status.
464 *
465 * So here we check if the alarm time is set by aie_timer, if yes, we
466 * should set normal alarm, if not, we should set auxiliary alarm which
467 * means it is just a wake event.
468 */
469 if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
470 return sprd_rtc_set_aux_alarm(dev, alrm);
471
472 /* clear the alarm interrupt status firstly */
473 ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
474 SPRD_RTC_ALARM_EN);
475 if (ret)
476 return ret;
477
478 ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
479 if (ret)
480 return ret;
481
482 if (alrm->enabled) {
483 ret = regmap_update_bits(rtc->regmap,
484 rtc->base + SPRD_RTC_INT_EN,
485 SPRD_RTC_ALARM_EN,
486 SPRD_RTC_ALARM_EN);
487 if (ret)
488 return ret;
489
490 /* unlock the alarm to enable the alarm function. */
491 ret = sprd_rtc_lock_alarm(rtc, false);
492 } else {
493 regmap_update_bits(rtc->regmap,
494 rtc->base + SPRD_RTC_INT_EN,
495 SPRD_RTC_ALARM_EN, 0);
496
497 /*
498 * Lock the alarm function in case fake alarm event will power
499 * up systems.
500 */
501 ret = sprd_rtc_lock_alarm(rtc, true);
502 }
503
504 return ret;
505 }
506
sprd_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)507 static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
508 {
509 struct sprd_rtc *rtc = dev_get_drvdata(dev);
510 int ret;
511
512 if (enabled) {
513 ret = regmap_update_bits(rtc->regmap,
514 rtc->base + SPRD_RTC_INT_EN,
515 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
516 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
517 if (ret)
518 return ret;
519
520 ret = sprd_rtc_lock_alarm(rtc, false);
521 } else {
522 regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
523 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
524
525 ret = sprd_rtc_lock_alarm(rtc, true);
526 }
527
528 return ret;
529 }
530
531 static const struct rtc_class_ops sprd_rtc_ops = {
532 .read_time = sprd_rtc_read_time,
533 .set_time = sprd_rtc_set_time,
534 .read_alarm = sprd_rtc_read_alarm,
535 .set_alarm = sprd_rtc_set_alarm,
536 .alarm_irq_enable = sprd_rtc_alarm_irq_enable,
537 };
538
sprd_rtc_handler(int irq,void * dev_id)539 static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
540 {
541 struct sprd_rtc *rtc = dev_id;
542 int ret;
543
544 ret = sprd_rtc_clear_alarm_ints(rtc);
545 if (ret)
546 return IRQ_RETVAL(ret);
547
548 rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
549 return IRQ_HANDLED;
550 }
551
sprd_rtc_check_power_down(struct sprd_rtc * rtc)552 static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
553 {
554 u32 val;
555 int ret;
556
557 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
558 if (ret)
559 return ret;
560
561 /*
562 * If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
563 * means the RTC has been powered down, so the RTC time values are
564 * invalid.
565 */
566 rtc->valid = val == SPRD_RTC_POWER_RESET_VALUE ? false : true;
567 return 0;
568 }
569
sprd_rtc_check_alarm_int(struct sprd_rtc * rtc)570 static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc)
571 {
572 u32 val;
573 int ret;
574
575 ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
576 if (ret)
577 return ret;
578
579 /*
580 * The SPRD_RTC_INT_EN register is not put in always-power-on region
581 * supplied by VDDRTC, so we should check if we need enable the alarm
582 * interrupt when system booting.
583 *
584 * If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in
585 * always-power-on region, that means we have set one alarm last time,
586 * so we should enable the alarm interrupt to help RTC core to see if
587 * there is an alarm already set in RTC hardware.
588 */
589 if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG))
590 return 0;
591
592 return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
593 SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN);
594 }
595
sprd_rtc_probe(struct platform_device * pdev)596 static int sprd_rtc_probe(struct platform_device *pdev)
597 {
598 struct device_node *node = pdev->dev.of_node;
599 struct sprd_rtc *rtc;
600 int ret;
601
602 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
603 if (!rtc)
604 return -ENOMEM;
605
606 rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
607 if (!rtc->regmap)
608 return -ENODEV;
609
610 ret = of_property_read_u32(node, "reg", &rtc->base);
611 if (ret) {
612 dev_err(&pdev->dev, "failed to get RTC base address\n");
613 return ret;
614 }
615
616 rtc->irq = platform_get_irq(pdev, 0);
617 if (rtc->irq < 0)
618 return rtc->irq;
619
620 rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
621 if (IS_ERR(rtc->rtc))
622 return PTR_ERR(rtc->rtc);
623
624 rtc->dev = &pdev->dev;
625 platform_set_drvdata(pdev, rtc);
626
627 /* check if we need set the alarm interrupt */
628 ret = sprd_rtc_check_alarm_int(rtc);
629 if (ret) {
630 dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n");
631 return ret;
632 }
633
634 /* check if RTC time values are valid */
635 ret = sprd_rtc_check_power_down(rtc);
636 if (ret) {
637 dev_err(&pdev->dev, "failed to check RTC time values\n");
638 return ret;
639 }
640
641 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
642 sprd_rtc_handler,
643 IRQF_ONESHOT | IRQF_EARLY_RESUME,
644 pdev->name, rtc);
645 if (ret < 0) {
646 dev_err(&pdev->dev, "failed to request RTC irq\n");
647 return ret;
648 }
649
650 device_init_wakeup(&pdev->dev, 1);
651
652 rtc->rtc->ops = &sprd_rtc_ops;
653 rtc->rtc->range_min = 0;
654 rtc->rtc->range_max = 5662310399LL;
655 ret = rtc_register_device(rtc->rtc);
656 if (ret) {
657 device_init_wakeup(&pdev->dev, 0);
658 return ret;
659 }
660
661 return 0;
662 }
663
664 static const struct of_device_id sprd_rtc_of_match[] = {
665 { .compatible = "sprd,sc2731-rtc", },
666 { },
667 };
668 MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
669
670 static struct platform_driver sprd_rtc_driver = {
671 .driver = {
672 .name = "sprd-rtc",
673 .of_match_table = sprd_rtc_of_match,
674 },
675 .probe = sprd_rtc_probe,
676 };
677 module_platform_driver(sprd_rtc_driver);
678
679 MODULE_LICENSE("GPL v2");
680 MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
681 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
682