1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * pm8xxx RTC driver
4  *
5  * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
6  * Copyright (c) 2023, Linaro Limited
7  */
8 #include <linux/efi.h>
9 #include <linux/of.h>
10 #include <linux/module.h>
11 #include <linux/nvmem-consumer.h>
12 #include <linux/init.h>
13 #include <linux/rtc.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm.h>
16 #include <linux/pm_wakeirq.h>
17 #include <linux/regmap.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/unaligned.h>
21 
22 #include <asm/byteorder.h>
23 
24 /* RTC_CTRL register bit fields */
25 #define PM8xxx_RTC_ENABLE		BIT(7)
26 #define PM8xxx_RTC_ALARM_CLEAR		BIT(0)
27 #define PM8xxx_RTC_ALARM_ENABLE		BIT(7)
28 
29 #define NUM_8_BIT_RTC_REGS		0x4
30 
31 /**
32  * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
33  * @ctrl:		address of control register
34  * @write:		base address of write registers
35  * @read:		base address of read registers
36  * @alarm_ctrl:		address of alarm control register
37  * @alarm_ctrl2:	address of alarm control2 register
38  * @alarm_rw:		base address of alarm read-write registers
39  * @alarm_en:		alarm enable mask
40  */
41 struct pm8xxx_rtc_regs {
42 	unsigned int ctrl;
43 	unsigned int write;
44 	unsigned int read;
45 	unsigned int alarm_ctrl;
46 	unsigned int alarm_ctrl2;
47 	unsigned int alarm_rw;
48 	unsigned int alarm_en;
49 };
50 
51 struct qcom_uefi_rtc_info {
52 	__le32	offset_gps;
53 	u8	reserved[8];
54 } __packed;
55 
56 /**
57  * struct pm8xxx_rtc -  RTC driver internal structure
58  * @rtc:		RTC device
59  * @regmap:		regmap used to access registers
60  * @allow_set_time:	whether the time can be set
61  * @use_uefi:		use UEFI variable as fallback for offset
62  * @alarm_irq:		alarm irq number
63  * @regs:		register description
64  * @dev:		device structure
65  * @rtc_info:		qcom uefi rtc-info structure
66  * @nvmem_cell:		nvmem cell for offset
67  * @offset:		offset from epoch in seconds
68  * @offset_dirty:	offset needs to be stored on shutdown
69  */
70 struct pm8xxx_rtc {
71 	struct rtc_device *rtc;
72 	struct regmap *regmap;
73 	bool allow_set_time;
74 	bool use_uefi;
75 	int alarm_irq;
76 	const struct pm8xxx_rtc_regs *regs;
77 	struct device *dev;
78 	struct qcom_uefi_rtc_info rtc_info;
79 	struct nvmem_cell *nvmem_cell;
80 	u32 offset;
81 	bool offset_dirty;
82 };
83 
84 #ifdef CONFIG_EFI
85 
86 MODULE_IMPORT_NS("EFIVAR");
87 
88 #define QCOM_UEFI_NAME	L"RTCInfo"
89 #define QCOM_UEFI_GUID	EFI_GUID(0x882f8c2b, 0x9646, 0x435f, \
90 				 0x8d, 0xe5, 0xf2, 0x08, 0xff, 0x80, 0xc1, 0xbd)
91 #define QCOM_UEFI_ATTRS	(EFI_VARIABLE_NON_VOLATILE | \
92 			 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
93 			 EFI_VARIABLE_RUNTIME_ACCESS)
94 
95 static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd)
96 {
97 	struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info;
98 	unsigned long size = sizeof(*rtc_info);
99 	struct device *dev = rtc_dd->dev;
100 	efi_status_t status;
101 	u32 offset_gps;
102 	int rc;
103 
104 	rc = efivar_lock();
105 	if (rc)
106 		return rc;
107 
108 	status = efivar_get_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID, NULL,
109 				     &size, rtc_info);
110 	efivar_unlock();
111 
112 	if (status != EFI_SUCCESS) {
113 		dev_dbg(dev, "failed to read UEFI offset: %lu\n", status);
114 		return efi_status_to_err(status);
115 	}
116 
117 	if (size != sizeof(*rtc_info)) {
118 		dev_dbg(dev, "unexpected UEFI structure size %lu\n", size);
119 		return -EINVAL;
120 	}
121 
122 	dev_dbg(dev, "uefi_rtc_info = %*ph\n", (int)size, rtc_info);
123 
124 	/* Convert from GPS to Unix time offset */
125 	offset_gps = le32_to_cpu(rtc_info->offset_gps);
126 	rtc_dd->offset = offset_gps + (u32)RTC_TIMESTAMP_EPOCH_GPS;
127 
128 	return 0;
129 }
130 
131 static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset)
132 {
133 	struct qcom_uefi_rtc_info *rtc_info = &rtc_dd->rtc_info;
134 	unsigned long size = sizeof(*rtc_info);
135 	struct device *dev = rtc_dd->dev;
136 	efi_status_t status;
137 	u32 offset_gps;
138 
139 	/* Convert from Unix to GPS time offset */
140 	offset_gps = offset - (u32)RTC_TIMESTAMP_EPOCH_GPS;
141 
142 	rtc_info->offset_gps = cpu_to_le32(offset_gps);
143 
144 	dev_dbg(dev, "efi_rtc_info = %*ph\n", (int)size, rtc_info);
145 
146 	status = efivar_set_variable(QCOM_UEFI_NAME, &QCOM_UEFI_GUID,
147 				     QCOM_UEFI_ATTRS, size, rtc_info);
148 	if (status != EFI_SUCCESS) {
149 		dev_dbg(dev, "failed to write UEFI offset: %lx\n", status);
150 		return efi_status_to_err(status);
151 	}
152 
153 	return 0;
154 }
155 
156 #else	/* CONFIG_EFI */
157 
158 static int pm8xxx_rtc_read_uefi_offset(struct pm8xxx_rtc *rtc_dd)
159 {
160 	return -ENODEV;
161 }
162 
163 static int pm8xxx_rtc_write_uefi_offset(struct pm8xxx_rtc *rtc_dd, u32 offset)
164 {
165 	return -ENODEV;
166 }
167 
168 #endif	/* CONFIG_EFI */
169 
170 static int pm8xxx_rtc_read_nvmem_offset(struct pm8xxx_rtc *rtc_dd)
171 {
172 	size_t len;
173 	void *buf;
174 	int rc;
175 
176 	buf = nvmem_cell_read(rtc_dd->nvmem_cell, &len);
177 	if (IS_ERR(buf)) {
178 		rc = PTR_ERR(buf);
179 		dev_dbg(rtc_dd->dev, "failed to read nvmem offset: %d\n", rc);
180 		return rc;
181 	}
182 
183 	if (len != sizeof(u32)) {
184 		dev_dbg(rtc_dd->dev, "unexpected nvmem cell size %zu\n", len);
185 		kfree(buf);
186 		return -EINVAL;
187 	}
188 
189 	rtc_dd->offset = get_unaligned_le32(buf);
190 
191 	kfree(buf);
192 
193 	return 0;
194 }
195 
196 static int pm8xxx_rtc_write_nvmem_offset(struct pm8xxx_rtc *rtc_dd, u32 offset)
197 {
198 	u8 buf[sizeof(u32)];
199 	int rc;
200 
201 	put_unaligned_le32(offset, buf);
202 
203 	rc = nvmem_cell_write(rtc_dd->nvmem_cell, buf, sizeof(buf));
204 	if (rc < 0) {
205 		dev_dbg(rtc_dd->dev, "failed to write nvmem offset: %d\n", rc);
206 		return rc;
207 	}
208 
209 	return 0;
210 }
211 
212 static int pm8xxx_rtc_read_raw(struct pm8xxx_rtc *rtc_dd, u32 *secs)
213 {
214 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
215 	u8 value[NUM_8_BIT_RTC_REGS];
216 	unsigned int reg;
217 	int rc;
218 
219 	rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
220 	if (rc)
221 		return rc;
222 
223 	/*
224 	 * Read the LSB again and check if there has been a carry over.
225 	 * If there has, redo the read operation.
226 	 */
227 	rc = regmap_read(rtc_dd->regmap, regs->read, &reg);
228 	if (rc < 0)
229 		return rc;
230 
231 	if (reg < value[0]) {
232 		rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value,
233 				      sizeof(value));
234 		if (rc)
235 			return rc;
236 	}
237 
238 	*secs = get_unaligned_le32(value);
239 
240 	return 0;
241 }
242 
243 static int pm8xxx_rtc_update_offset(struct pm8xxx_rtc *rtc_dd, u32 secs)
244 {
245 	u32 raw_secs;
246 	u32 offset;
247 	int rc;
248 
249 	if (!rtc_dd->nvmem_cell && !rtc_dd->use_uefi)
250 		return -ENODEV;
251 
252 	rc = pm8xxx_rtc_read_raw(rtc_dd, &raw_secs);
253 	if (rc)
254 		return rc;
255 
256 	offset = secs - raw_secs;
257 
258 	if (offset == rtc_dd->offset)
259 		return 0;
260 
261 	/*
262 	 * Reduce flash wear by deferring updates due to clock drift until
263 	 * shutdown.
264 	 */
265 	if (abs_diff(offset, rtc_dd->offset) < 30) {
266 		rtc_dd->offset_dirty = true;
267 		goto out;
268 	}
269 
270 	if (rtc_dd->nvmem_cell)
271 		rc = pm8xxx_rtc_write_nvmem_offset(rtc_dd, offset);
272 	else
273 		rc = pm8xxx_rtc_write_uefi_offset(rtc_dd, offset);
274 
275 	if (rc)
276 		return rc;
277 
278 	rtc_dd->offset_dirty = false;
279 out:
280 	rtc_dd->offset = offset;
281 
282 	return 0;
283 }
284 
285 /*
286  * Steps to write the RTC registers.
287  * 1. Disable alarm if enabled.
288  * 2. Disable rtc if enabled.
289  * 3. Write 0x00 to LSB.
290  * 4. Write Byte[1], Byte[2], Byte[3] then Byte[0].
291  * 5. Enable rtc if disabled in step 2.
292  * 6. Enable alarm if disabled in step 1.
293  */
294 static int __pm8xxx_rtc_set_time(struct pm8xxx_rtc *rtc_dd, u32 secs)
295 {
296 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
297 	u8 value[NUM_8_BIT_RTC_REGS];
298 	bool alarm_enabled;
299 	int rc;
300 
301 	put_unaligned_le32(secs, value);
302 
303 	rc = regmap_update_bits_check(rtc_dd->regmap, regs->alarm_ctrl,
304 				      regs->alarm_en, 0, &alarm_enabled);
305 	if (rc)
306 		return rc;
307 
308 	/* Disable RTC */
309 	rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 0);
310 	if (rc)
311 		return rc;
312 
313 	/* Write 0 to Byte[0] */
314 	rc = regmap_write(rtc_dd->regmap, regs->write, 0);
315 	if (rc)
316 		return rc;
317 
318 	/* Write Byte[1], Byte[2], Byte[3] */
319 	rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
320 			       &value[1], sizeof(value) - 1);
321 	if (rc)
322 		return rc;
323 
324 	/* Write Byte[0] */
325 	rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
326 	if (rc)
327 		return rc;
328 
329 	/* Enable RTC */
330 	rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
331 				PM8xxx_RTC_ENABLE);
332 	if (rc)
333 		return rc;
334 
335 	if (alarm_enabled) {
336 		rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
337 					regs->alarm_en, regs->alarm_en);
338 		if (rc)
339 			return rc;
340 	}
341 
342 	return 0;
343 }
344 
345 static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
346 {
347 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
348 	u32 secs;
349 	int rc;
350 
351 	secs = rtc_tm_to_time64(tm);
352 
353 	if (rtc_dd->allow_set_time)
354 		rc = __pm8xxx_rtc_set_time(rtc_dd, secs);
355 	else
356 		rc = pm8xxx_rtc_update_offset(rtc_dd, secs);
357 
358 	if (rc)
359 		return rc;
360 
361 	dev_dbg(dev, "set time: %ptRd %ptRt (%u + %u)\n", tm, tm,
362 			secs - rtc_dd->offset, rtc_dd->offset);
363 	return 0;
364 }
365 
366 static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
367 {
368 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
369 	u32 secs;
370 	int rc;
371 
372 	rc = pm8xxx_rtc_read_raw(rtc_dd, &secs);
373 	if (rc)
374 		return rc;
375 
376 	secs += rtc_dd->offset;
377 	rtc_time64_to_tm(secs, tm);
378 
379 	dev_dbg(dev, "read time: %ptRd %ptRt (%u + %u)\n", tm, tm,
380 			secs - rtc_dd->offset, rtc_dd->offset);
381 	return 0;
382 }
383 
384 static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
385 {
386 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
387 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
388 	u8 value[NUM_8_BIT_RTC_REGS];
389 	u32 secs;
390 	int rc;
391 
392 	secs = rtc_tm_to_time64(&alarm->time);
393 	secs -= rtc_dd->offset;
394 	put_unaligned_le32(secs, value);
395 
396 	rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
397 				regs->alarm_en, 0);
398 	if (rc)
399 		return rc;
400 
401 	rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
402 			       sizeof(value));
403 	if (rc)
404 		return rc;
405 
406 	if (alarm->enabled) {
407 		rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
408 					regs->alarm_en, regs->alarm_en);
409 		if (rc)
410 			return rc;
411 	}
412 
413 	dev_dbg(dev, "set alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
414 
415 	return 0;
416 }
417 
418 static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
419 {
420 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
421 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
422 	u8 value[NUM_8_BIT_RTC_REGS];
423 	unsigned int ctrl_reg;
424 	u32 secs;
425 	int rc;
426 
427 	rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
428 			      sizeof(value));
429 	if (rc)
430 		return rc;
431 
432 	secs = get_unaligned_le32(value);
433 	secs += rtc_dd->offset;
434 	rtc_time64_to_tm(secs, &alarm->time);
435 
436 	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
437 	if (rc)
438 		return rc;
439 
440 	alarm->enabled = !!(ctrl_reg & PM8xxx_RTC_ALARM_ENABLE);
441 
442 	dev_dbg(dev, "read alarm: %ptRd %ptRt\n", &alarm->time, &alarm->time);
443 
444 	return 0;
445 }
446 
447 static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
448 {
449 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
450 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
451 	u8 value[NUM_8_BIT_RTC_REGS] = {0};
452 	unsigned int val;
453 	int rc;
454 
455 	if (enable)
456 		val = regs->alarm_en;
457 	else
458 		val = 0;
459 
460 	rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
461 				regs->alarm_en, val);
462 	if (rc)
463 		return rc;
464 
465 	/* Clear alarm register */
466 	if (!enable) {
467 		rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
468 				       sizeof(value));
469 		if (rc)
470 			return rc;
471 	}
472 
473 	return 0;
474 }
475 
476 static const struct rtc_class_ops pm8xxx_rtc_ops = {
477 	.read_time	= pm8xxx_rtc_read_time,
478 	.set_time	= pm8xxx_rtc_set_time,
479 	.set_alarm	= pm8xxx_rtc_set_alarm,
480 	.read_alarm	= pm8xxx_rtc_read_alarm,
481 	.alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
482 };
483 
484 static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
485 {
486 	struct pm8xxx_rtc *rtc_dd = dev_id;
487 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
488 	int rc;
489 
490 	rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
491 
492 	/* Disable alarm */
493 	rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
494 				regs->alarm_en, 0);
495 	if (rc)
496 		return IRQ_NONE;
497 
498 	/* Clear alarm status */
499 	rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl2,
500 				PM8xxx_RTC_ALARM_CLEAR, 0);
501 	if (rc)
502 		return IRQ_NONE;
503 
504 	return IRQ_HANDLED;
505 }
506 
507 static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
508 {
509 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
510 
511 	return regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE,
512 				  PM8xxx_RTC_ENABLE);
513 }
514 
515 static const struct pm8xxx_rtc_regs pm8921_regs = {
516 	.ctrl		= 0x11d,
517 	.write		= 0x11f,
518 	.read		= 0x123,
519 	.alarm_rw	= 0x127,
520 	.alarm_ctrl	= 0x11d,
521 	.alarm_ctrl2	= 0x11e,
522 	.alarm_en	= BIT(1),
523 };
524 
525 static const struct pm8xxx_rtc_regs pm8058_regs = {
526 	.ctrl		= 0x1e8,
527 	.write		= 0x1ea,
528 	.read		= 0x1ee,
529 	.alarm_rw	= 0x1f2,
530 	.alarm_ctrl	= 0x1e8,
531 	.alarm_ctrl2	= 0x1e9,
532 	.alarm_en	= BIT(1),
533 };
534 
535 static const struct pm8xxx_rtc_regs pm8941_regs = {
536 	.ctrl		= 0x6046,
537 	.write		= 0x6040,
538 	.read		= 0x6048,
539 	.alarm_rw	= 0x6140,
540 	.alarm_ctrl	= 0x6146,
541 	.alarm_ctrl2	= 0x6148,
542 	.alarm_en	= BIT(7),
543 };
544 
545 static const struct pm8xxx_rtc_regs pmk8350_regs = {
546 	.ctrl		= 0x6146,
547 	.write		= 0x6140,
548 	.read		= 0x6148,
549 	.alarm_rw	= 0x6240,
550 	.alarm_ctrl	= 0x6246,
551 	.alarm_ctrl2	= 0x6248,
552 	.alarm_en	= BIT(7),
553 };
554 
555 static const struct of_device_id pm8xxx_id_table[] = {
556 	{ .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
557 	{ .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
558 	{ .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
559 	{ .compatible = "qcom,pmk8350-rtc", .data = &pmk8350_regs },
560 	{ },
561 };
562 MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
563 
564 static int pm8xxx_rtc_probe_offset(struct pm8xxx_rtc *rtc_dd)
565 {
566 	int rc;
567 
568 	rtc_dd->nvmem_cell = devm_nvmem_cell_get(rtc_dd->dev, "offset");
569 	if (IS_ERR(rtc_dd->nvmem_cell)) {
570 		rc = PTR_ERR(rtc_dd->nvmem_cell);
571 		if (rc != -ENOENT)
572 			return rc;
573 		rtc_dd->nvmem_cell = NULL;
574 	} else {
575 		return pm8xxx_rtc_read_nvmem_offset(rtc_dd);
576 	}
577 
578 	/* Use UEFI storage as fallback if available */
579 	rtc_dd->use_uefi = of_property_read_bool(rtc_dd->dev->of_node,
580 						 "qcom,uefi-rtc-info");
581 	if (!rtc_dd->use_uefi)
582 		return 0;
583 
584 	if (!efivar_is_available()) {
585 		if (IS_ENABLED(CONFIG_EFI))
586 			return -EPROBE_DEFER;
587 
588 		dev_warn(rtc_dd->dev, "efivars not available\n");
589 		rtc_dd->use_uefi = false;
590 	}
591 
592 	return pm8xxx_rtc_read_uefi_offset(rtc_dd);
593 }
594 
595 static int pm8xxx_rtc_probe(struct platform_device *pdev)
596 {
597 	const struct of_device_id *match;
598 	struct pm8xxx_rtc *rtc_dd;
599 	int rc;
600 
601 	match = of_match_node(pm8xxx_id_table, pdev->dev.of_node);
602 	if (!match)
603 		return -ENXIO;
604 
605 	rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
606 	if (rtc_dd == NULL)
607 		return -ENOMEM;
608 
609 	rtc_dd->regs = match->data;
610 	rtc_dd->dev = &pdev->dev;
611 
612 	rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL);
613 	if (!rtc_dd->regmap)
614 		return -ENXIO;
615 
616 	if (!of_property_read_bool(pdev->dev.of_node, "qcom,no-alarm")) {
617 		rtc_dd->alarm_irq = platform_get_irq(pdev, 0);
618 		if (rtc_dd->alarm_irq < 0)
619 			return -ENXIO;
620 	}
621 
622 	rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
623 						      "allow-set-time");
624 	if (!rtc_dd->allow_set_time) {
625 		rc = pm8xxx_rtc_probe_offset(rtc_dd);
626 		if (rc)
627 			return rc;
628 	}
629 
630 	rc = pm8xxx_rtc_enable(rtc_dd);
631 	if (rc)
632 		return rc;
633 
634 	platform_set_drvdata(pdev, rtc_dd);
635 
636 	rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev);
637 	if (IS_ERR(rtc_dd->rtc))
638 		return PTR_ERR(rtc_dd->rtc);
639 
640 	rtc_dd->rtc->ops = &pm8xxx_rtc_ops;
641 	rtc_dd->rtc->range_max = U32_MAX;
642 
643 	if (rtc_dd->alarm_irq) {
644 		rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq,
645 						  pm8xxx_alarm_trigger,
646 						  IRQF_TRIGGER_RISING,
647 						  "pm8xxx_rtc_alarm", rtc_dd);
648 		if (rc < 0)
649 			return rc;
650 
651 		rc = devm_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq);
652 		if (rc)
653 			return rc;
654 
655 		devm_device_init_wakeup(&pdev->dev);
656 	} else {
657 		clear_bit(RTC_FEATURE_ALARM, rtc_dd->rtc->features);
658 	}
659 
660 	return devm_rtc_register_device(rtc_dd->rtc);
661 }
662 
663 static void pm8xxx_shutdown(struct platform_device *pdev)
664 {
665 	struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
666 
667 	if (rtc_dd->offset_dirty) {
668 		if (rtc_dd->nvmem_cell)
669 			pm8xxx_rtc_write_nvmem_offset(rtc_dd, rtc_dd->offset);
670 		else
671 			pm8xxx_rtc_write_uefi_offset(rtc_dd, rtc_dd->offset);
672 	}
673 }
674 
675 static struct platform_driver pm8xxx_rtc_driver = {
676 	.probe		= pm8xxx_rtc_probe,
677 	.shutdown	= pm8xxx_shutdown,
678 	.driver	= {
679 		.name		= "rtc-pm8xxx",
680 		.of_match_table	= pm8xxx_id_table,
681 	},
682 };
683 
684 module_platform_driver(pm8xxx_rtc_driver);
685 
686 MODULE_DESCRIPTION("PMIC8xxx RTC driver");
687 MODULE_LICENSE("GPL v2");
688 MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");
689 MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
690