xref: /openbmc/linux/drivers/rtc/rtc-rv3032.c (revision 7a010c3c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * RTC driver for the Micro Crystal RV3032
4  *
5  * Copyright (C) 2020 Micro Crystal SA
6  *
7  * Alexandre Belloni <alexandre.belloni@bootlin.com>
8  *
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/clk-provider.h>
13 #include <linux/bcd.h>
14 #include <linux/bitfield.h>
15 #include <linux/bitops.h>
16 #include <linux/hwmon.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/kernel.h>
20 #include <linux/log2.h>
21 #include <linux/module.h>
22 #include <linux/of_device.h>
23 #include <linux/regmap.h>
24 #include <linux/rtc.h>
25 
26 #define RV3032_SEC			0x01
27 #define RV3032_MIN			0x02
28 #define RV3032_HOUR			0x03
29 #define RV3032_WDAY			0x04
30 #define RV3032_DAY			0x05
31 #define RV3032_MONTH			0x06
32 #define RV3032_YEAR			0x07
33 #define RV3032_ALARM_MIN		0x08
34 #define RV3032_ALARM_HOUR		0x09
35 #define RV3032_ALARM_DAY		0x0A
36 #define RV3032_STATUS			0x0D
37 #define RV3032_TLSB			0x0E
38 #define RV3032_TMSB			0x0F
39 #define RV3032_CTRL1			0x10
40 #define RV3032_CTRL2			0x11
41 #define RV3032_CTRL3			0x12
42 #define RV3032_TS_CTRL			0x13
43 #define RV3032_CLK_IRQ			0x14
44 #define RV3032_EEPROM_ADDR		0x3D
45 #define RV3032_EEPROM_DATA		0x3E
46 #define RV3032_EEPROM_CMD		0x3F
47 #define RV3032_RAM1			0x40
48 #define RV3032_PMU			0xC0
49 #define RV3032_OFFSET			0xC1
50 #define RV3032_CLKOUT1			0xC2
51 #define RV3032_CLKOUT2			0xC3
52 #define RV3032_TREF0			0xC4
53 #define RV3032_TREF1			0xC5
54 
55 #define RV3032_STATUS_VLF		BIT(0)
56 #define RV3032_STATUS_PORF		BIT(1)
57 #define RV3032_STATUS_EVF		BIT(2)
58 #define RV3032_STATUS_AF		BIT(3)
59 #define RV3032_STATUS_TF		BIT(4)
60 #define RV3032_STATUS_UF		BIT(5)
61 #define RV3032_STATUS_TLF		BIT(6)
62 #define RV3032_STATUS_THF		BIT(7)
63 
64 #define RV3032_TLSB_CLKF		BIT(1)
65 #define RV3032_TLSB_EEBUSY		BIT(2)
66 #define RV3032_TLSB_TEMP		GENMASK(7, 4)
67 
68 #define RV3032_CLKOUT2_HFD_MSK		GENMASK(4, 0)
69 #define RV3032_CLKOUT2_FD_MSK		GENMASK(6, 5)
70 #define RV3032_CLKOUT2_OS		BIT(7)
71 
72 #define RV3032_CTRL1_EERD		BIT(3)
73 #define RV3032_CTRL1_WADA		BIT(5)
74 
75 #define RV3032_CTRL2_STOP		BIT(0)
76 #define RV3032_CTRL2_EIE		BIT(2)
77 #define RV3032_CTRL2_AIE		BIT(3)
78 #define RV3032_CTRL2_TIE		BIT(4)
79 #define RV3032_CTRL2_UIE		BIT(5)
80 #define RV3032_CTRL2_CLKIE		BIT(6)
81 #define RV3032_CTRL2_TSE		BIT(7)
82 
83 #define RV3032_PMU_TCM			GENMASK(1, 0)
84 #define RV3032_PMU_TCR			GENMASK(3, 2)
85 #define RV3032_PMU_BSM			GENMASK(5, 4)
86 #define RV3032_PMU_NCLKE		BIT(6)
87 
88 #define RV3032_PMU_BSM_DSM		1
89 #define RV3032_PMU_BSM_LSM		2
90 
91 #define RV3032_OFFSET_MSK		GENMASK(5, 0)
92 
93 #define RV3032_EVT_CTRL_TSR		BIT(2)
94 
95 #define RV3032_EEPROM_CMD_UPDATE	0x11
96 #define RV3032_EEPROM_CMD_WRITE		0x21
97 #define RV3032_EEPROM_CMD_READ		0x22
98 
99 #define RV3032_EEPROM_USER		0xCB
100 
101 #define RV3032_EEBUSY_POLL		10000
102 #define RV3032_EEBUSY_TIMEOUT		100000
103 
104 #define OFFSET_STEP_PPT			238419
105 
106 struct rv3032_data {
107 	struct regmap *regmap;
108 	struct rtc_device *rtc;
109 #ifdef CONFIG_COMMON_CLK
110 	struct clk_hw clkout_hw;
111 #endif
112 };
113 
114 static u16 rv3032_trickle_resistors[] = {1000, 2000, 7000, 11000};
115 static u16 rv3032_trickle_voltages[] = {0, 1750, 3000, 4400};
116 
117 static int rv3032_exit_eerd(struct rv3032_data *rv3032, u32 eerd)
118 {
119 	if (eerd)
120 		return 0;
121 
122 	return regmap_update_bits(rv3032->regmap, RV3032_CTRL1, RV3032_CTRL1_EERD, 0);
123 }
124 
125 static int rv3032_enter_eerd(struct rv3032_data *rv3032, u32 *eerd)
126 {
127 	u32 ctrl1, status;
128 	int ret;
129 
130 	ret = regmap_read(rv3032->regmap, RV3032_CTRL1, &ctrl1);
131 	if (ret)
132 		return ret;
133 
134 	*eerd = ctrl1 & RV3032_CTRL1_EERD;
135 	if (*eerd)
136 		return 0;
137 
138 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
139 				 RV3032_CTRL1_EERD, RV3032_CTRL1_EERD);
140 	if (ret)
141 		return ret;
142 
143 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
144 				       !(status & RV3032_TLSB_EEBUSY),
145 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
146 	if (ret) {
147 		rv3032_exit_eerd(rv3032, *eerd);
148 
149 		return ret;
150 	}
151 
152 	return 0;
153 }
154 
155 static int rv3032_update_cfg(struct rv3032_data *rv3032, unsigned int reg,
156 			     unsigned int mask, unsigned int val)
157 {
158 	u32 status, eerd;
159 	int ret;
160 
161 	ret = rv3032_enter_eerd(rv3032, &eerd);
162 	if (ret)
163 		return ret;
164 
165 	ret = regmap_update_bits(rv3032->regmap, reg, mask, val);
166 	if (ret)
167 		goto exit_eerd;
168 
169 	ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
170 	if (ret)
171 		goto exit_eerd;
172 
173 	usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
174 
175 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
176 				       !(status & RV3032_TLSB_EEBUSY),
177 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
178 
179 exit_eerd:
180 	rv3032_exit_eerd(rv3032, eerd);
181 
182 	return ret;
183 }
184 
185 static irqreturn_t rv3032_handle_irq(int irq, void *dev_id)
186 {
187 	struct rv3032_data *rv3032 = dev_id;
188 	unsigned long events = 0;
189 	u32 status = 0, ctrl = 0;
190 
191 	if (regmap_read(rv3032->regmap, RV3032_STATUS, &status) < 0 ||
192 	    status == 0) {
193 		return IRQ_NONE;
194 	}
195 
196 	if (status & RV3032_STATUS_TF) {
197 		status |= RV3032_STATUS_TF;
198 		ctrl |= RV3032_CTRL2_TIE;
199 		events |= RTC_PF;
200 	}
201 
202 	if (status & RV3032_STATUS_AF) {
203 		status |= RV3032_STATUS_AF;
204 		ctrl |= RV3032_CTRL2_AIE;
205 		events |= RTC_AF;
206 	}
207 
208 	if (status & RV3032_STATUS_UF) {
209 		status |= RV3032_STATUS_UF;
210 		ctrl |= RV3032_CTRL2_UIE;
211 		events |= RTC_UF;
212 	}
213 
214 	if (events) {
215 		rtc_update_irq(rv3032->rtc, 1, events);
216 		regmap_update_bits(rv3032->regmap, RV3032_STATUS, status, 0);
217 		regmap_update_bits(rv3032->regmap, RV3032_CTRL2, ctrl, 0);
218 	}
219 
220 	return IRQ_HANDLED;
221 }
222 
223 static int rv3032_get_time(struct device *dev, struct rtc_time *tm)
224 {
225 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
226 	u8 date[7];
227 	int ret, status;
228 
229 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
230 	if (ret < 0)
231 		return ret;
232 
233 	if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
234 		return -EINVAL;
235 
236 	ret = regmap_bulk_read(rv3032->regmap, RV3032_SEC, date, sizeof(date));
237 	if (ret)
238 		return ret;
239 
240 	tm->tm_sec  = bcd2bin(date[0] & 0x7f);
241 	tm->tm_min  = bcd2bin(date[1] & 0x7f);
242 	tm->tm_hour = bcd2bin(date[2] & 0x3f);
243 	tm->tm_wday = date[3] & 0x7;
244 	tm->tm_mday = bcd2bin(date[4] & 0x3f);
245 	tm->tm_mon  = bcd2bin(date[5] & 0x1f) - 1;
246 	tm->tm_year = bcd2bin(date[6]) + 100;
247 
248 	return 0;
249 }
250 
251 static int rv3032_set_time(struct device *dev, struct rtc_time *tm)
252 {
253 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
254 	u8 date[7];
255 	int ret;
256 
257 	date[0] = bin2bcd(tm->tm_sec);
258 	date[1] = bin2bcd(tm->tm_min);
259 	date[2] = bin2bcd(tm->tm_hour);
260 	date[3] = tm->tm_wday;
261 	date[4] = bin2bcd(tm->tm_mday);
262 	date[5] = bin2bcd(tm->tm_mon + 1);
263 	date[6] = bin2bcd(tm->tm_year - 100);
264 
265 	ret = regmap_bulk_write(rv3032->regmap, RV3032_SEC, date,
266 				sizeof(date));
267 	if (ret)
268 		return ret;
269 
270 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
271 				 RV3032_STATUS_PORF | RV3032_STATUS_VLF, 0);
272 
273 	return ret;
274 }
275 
276 static int rv3032_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
277 {
278 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
279 	u8 alarmvals[3];
280 	int status, ctrl, ret;
281 
282 	ret = regmap_bulk_read(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
283 			       sizeof(alarmvals));
284 	if (ret)
285 		return ret;
286 
287 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
288 	if (ret < 0)
289 		return ret;
290 
291 	ret = regmap_read(rv3032->regmap, RV3032_CTRL2, &ctrl);
292 	if (ret < 0)
293 		return ret;
294 
295 	alrm->time.tm_sec  = 0;
296 	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
297 	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
298 	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
299 
300 	alrm->enabled = !!(ctrl & RV3032_CTRL2_AIE);
301 	alrm->pending = (status & RV3032_STATUS_AF) && alrm->enabled;
302 
303 	return 0;
304 }
305 
306 static int rv3032_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
307 {
308 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
309 	u8 alarmvals[3];
310 	u8 ctrl = 0;
311 	int ret;
312 
313 	/* The alarm has no seconds, round up to nearest minute */
314 	if (alrm->time.tm_sec) {
315 		time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
316 
317 		alarm_time += 60 - alrm->time.tm_sec;
318 		rtc_time64_to_tm(alarm_time, &alrm->time);
319 	}
320 
321 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
322 				 RV3032_CTRL2_AIE | RV3032_CTRL2_UIE, 0);
323 	if (ret)
324 		return ret;
325 
326 	alarmvals[0] = bin2bcd(alrm->time.tm_min);
327 	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
328 	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
329 
330 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
331 				 RV3032_STATUS_AF, 0);
332 	if (ret)
333 		return ret;
334 
335 	ret = regmap_bulk_write(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
336 				sizeof(alarmvals));
337 	if (ret)
338 		return ret;
339 
340 	if (alrm->enabled) {
341 		if (rv3032->rtc->uie_rtctimer.enabled)
342 			ctrl |= RV3032_CTRL2_UIE;
343 		if (rv3032->rtc->aie_timer.enabled)
344 			ctrl |= RV3032_CTRL2_AIE;
345 	}
346 
347 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
348 				 RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
349 
350 	return ret;
351 }
352 
353 static int rv3032_alarm_irq_enable(struct device *dev, unsigned int enabled)
354 {
355 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
356 	int ctrl = 0, ret;
357 
358 	if (enabled) {
359 		if (rv3032->rtc->uie_rtctimer.enabled)
360 			ctrl |= RV3032_CTRL2_UIE;
361 		if (rv3032->rtc->aie_timer.enabled)
362 			ctrl |= RV3032_CTRL2_AIE;
363 	}
364 
365 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
366 				 RV3032_STATUS_AF | RV3032_STATUS_UF, 0);
367 	if (ret)
368 		return ret;
369 
370 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
371 				 RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
372 	if (ret)
373 		return ret;
374 
375 	return 0;
376 }
377 
378 static int rv3032_read_offset(struct device *dev, long *offset)
379 {
380 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
381 	int ret, value, steps;
382 
383 	ret = regmap_read(rv3032->regmap, RV3032_OFFSET, &value);
384 	if (ret < 0)
385 		return ret;
386 
387 	steps = sign_extend32(FIELD_GET(RV3032_OFFSET_MSK, value), 5);
388 
389 	*offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
390 
391 	return 0;
392 }
393 
394 static int rv3032_set_offset(struct device *dev, long offset)
395 {
396 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
397 
398 	offset = clamp(offset, -7629L, 7391L) * 1000;
399 	offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
400 
401 	return rv3032_update_cfg(rv3032, RV3032_OFFSET, RV3032_OFFSET_MSK,
402 				 FIELD_PREP(RV3032_OFFSET_MSK, offset));
403 }
404 
405 static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
406 {
407 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
408 	int status, val = 0, ret = 0;
409 
410 	switch (cmd) {
411 	case RTC_VL_READ:
412 		ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
413 		if (ret < 0)
414 			return ret;
415 
416 		if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
417 			val = RTC_VL_DATA_INVALID;
418 		return put_user(val, (unsigned int __user *)arg);
419 
420 	default:
421 		return -ENOIOCTLCMD;
422 	}
423 }
424 
425 static int rv3032_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes)
426 {
427 	return regmap_bulk_write(priv, RV3032_RAM1 + offset, val, bytes);
428 }
429 
430 static int rv3032_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes)
431 {
432 	return regmap_bulk_read(priv, RV3032_RAM1 + offset, val, bytes);
433 }
434 
435 static int rv3032_eeprom_write(void *priv, unsigned int offset, void *val, size_t bytes)
436 {
437 	struct rv3032_data *rv3032 = priv;
438 	u32 status, eerd;
439 	int i, ret;
440 	u8 *buf = val;
441 
442 	ret = rv3032_enter_eerd(rv3032, &eerd);
443 	if (ret)
444 		return ret;
445 
446 	for (i = 0; i < bytes; i++) {
447 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
448 				   RV3032_EEPROM_USER + offset + i);
449 		if (ret)
450 			goto exit_eerd;
451 
452 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_DATA, buf[i]);
453 		if (ret)
454 			goto exit_eerd;
455 
456 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
457 				   RV3032_EEPROM_CMD_WRITE);
458 		if (ret)
459 			goto exit_eerd;
460 
461 		usleep_range(RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
462 
463 		ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
464 					       !(status & RV3032_TLSB_EEBUSY),
465 					       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
466 		if (ret)
467 			goto exit_eerd;
468 	}
469 
470 exit_eerd:
471 	rv3032_exit_eerd(rv3032, eerd);
472 
473 	return ret;
474 }
475 
476 static int rv3032_eeprom_read(void *priv, unsigned int offset, void *val, size_t bytes)
477 {
478 	struct rv3032_data *rv3032 = priv;
479 	u32 status, eerd, data;
480 	int i, ret;
481 	u8 *buf = val;
482 
483 	ret = rv3032_enter_eerd(rv3032, &eerd);
484 	if (ret)
485 		return ret;
486 
487 	for (i = 0; i < bytes; i++) {
488 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
489 				   RV3032_EEPROM_USER + offset + i);
490 		if (ret)
491 			goto exit_eerd;
492 
493 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
494 				   RV3032_EEPROM_CMD_READ);
495 		if (ret)
496 			goto exit_eerd;
497 
498 		ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
499 					       !(status & RV3032_TLSB_EEBUSY),
500 					       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
501 		if (ret)
502 			goto exit_eerd;
503 
504 		ret = regmap_read(rv3032->regmap, RV3032_EEPROM_DATA, &data);
505 		if (ret)
506 			goto exit_eerd;
507 		buf[i] = data;
508 	}
509 
510 exit_eerd:
511 	rv3032_exit_eerd(rv3032, eerd);
512 
513 	return ret;
514 }
515 
516 static int rv3032_trickle_charger_setup(struct device *dev, struct rv3032_data *rv3032)
517 {
518 	u32 val, ohms, voltage;
519 	int i;
520 
521 	val = FIELD_PREP(RV3032_PMU_TCM, 1) | FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_DSM);
522 	if (!device_property_read_u32(dev, "trickle-voltage-millivolt", &voltage)) {
523 		for (i = 0; i < ARRAY_SIZE(rv3032_trickle_voltages); i++)
524 			if (voltage == rv3032_trickle_voltages[i])
525 				break;
526 		if (i < ARRAY_SIZE(rv3032_trickle_voltages))
527 			val = FIELD_PREP(RV3032_PMU_TCM, i) |
528 			      FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_LSM);
529 	}
530 
531 	if (device_property_read_u32(dev, "trickle-resistor-ohms", &ohms))
532 		return 0;
533 
534 	for (i = 0; i < ARRAY_SIZE(rv3032_trickle_resistors); i++)
535 		if (ohms == rv3032_trickle_resistors[i])
536 			break;
537 
538 	if (i >= ARRAY_SIZE(rv3032_trickle_resistors)) {
539 		dev_warn(dev, "invalid trickle resistor value\n");
540 
541 		return 0;
542 	}
543 
544 	return rv3032_update_cfg(rv3032, RV3032_PMU,
545 				 RV3032_PMU_TCR | RV3032_PMU_TCM | RV3032_PMU_BSM,
546 				 val | FIELD_PREP(RV3032_PMU_TCR, i));
547 }
548 
549 #ifdef CONFIG_COMMON_CLK
550 #define clkout_hw_to_rv3032(hw) container_of(hw, struct rv3032_data, clkout_hw)
551 
552 static int clkout_xtal_rates[] = {
553 	32768,
554 	1024,
555 	64,
556 	1,
557 };
558 
559 #define RV3032_HFD_STEP 8192
560 
561 static unsigned long rv3032_clkout_recalc_rate(struct clk_hw *hw,
562 					       unsigned long parent_rate)
563 {
564 	int clkout, ret;
565 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
566 
567 	ret = regmap_read(rv3032->regmap, RV3032_CLKOUT2, &clkout);
568 	if (ret < 0)
569 		return 0;
570 
571 	if (clkout & RV3032_CLKOUT2_OS) {
572 		unsigned long rate = FIELD_GET(RV3032_CLKOUT2_HFD_MSK, clkout) << 8;
573 
574 		ret = regmap_read(rv3032->regmap, RV3032_CLKOUT1, &clkout);
575 		if (ret < 0)
576 			return 0;
577 
578 		rate += clkout + 1;
579 
580 		return rate * RV3032_HFD_STEP;
581 	}
582 
583 	return clkout_xtal_rates[FIELD_GET(RV3032_CLKOUT2_FD_MSK, clkout)];
584 }
585 
586 static long rv3032_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
587 				     unsigned long *prate)
588 {
589 	int i, hfd;
590 
591 	if (rate < RV3032_HFD_STEP)
592 		for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++)
593 			if (clkout_xtal_rates[i] <= rate)
594 				return clkout_xtal_rates[i];
595 
596 	hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
597 
598 	return RV3032_HFD_STEP * clamp(hfd, 0, 8192);
599 }
600 
601 static int rv3032_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
602 				  unsigned long parent_rate)
603 {
604 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
605 	u32 status, eerd;
606 	int i, hfd, ret;
607 
608 	for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++) {
609 		if (clkout_xtal_rates[i] == rate) {
610 			return rv3032_update_cfg(rv3032, RV3032_CLKOUT2, 0xff,
611 						 FIELD_PREP(RV3032_CLKOUT2_FD_MSK, i));
612 		}
613 	}
614 
615 	hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
616 	hfd = clamp(hfd, 1, 8192) - 1;
617 
618 	ret = rv3032_enter_eerd(rv3032, &eerd);
619 	if (ret)
620 		goto exit_eerd;
621 
622 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT1, hfd & 0xff);
623 	if (ret)
624 		return ret;
625 
626 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT2, RV3032_CLKOUT2_OS |
627 			    FIELD_PREP(RV3032_CLKOUT2_HFD_MSK, hfd >> 8));
628 	if (ret)
629 		goto exit_eerd;
630 
631 	ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
632 	if (ret)
633 		goto exit_eerd;
634 
635 	usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
636 
637 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
638 				       !(status & RV3032_TLSB_EEBUSY),
639 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
640 
641 exit_eerd:
642 	rv3032_exit_eerd(rv3032, eerd);
643 
644 	return ret;
645 }
646 
647 static int rv3032_clkout_prepare(struct clk_hw *hw)
648 {
649 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
650 
651 	return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, 0);
652 }
653 
654 static void rv3032_clkout_unprepare(struct clk_hw *hw)
655 {
656 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
657 
658 	rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, RV3032_PMU_NCLKE);
659 }
660 
661 static int rv3032_clkout_is_prepared(struct clk_hw *hw)
662 {
663 	int val, ret;
664 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
665 
666 	ret = regmap_read(rv3032->regmap, RV3032_PMU, &val);
667 	if (ret < 0)
668 		return ret;
669 
670 	return !(val & RV3032_PMU_NCLKE);
671 }
672 
673 static const struct clk_ops rv3032_clkout_ops = {
674 	.prepare = rv3032_clkout_prepare,
675 	.unprepare = rv3032_clkout_unprepare,
676 	.is_prepared = rv3032_clkout_is_prepared,
677 	.recalc_rate = rv3032_clkout_recalc_rate,
678 	.round_rate = rv3032_clkout_round_rate,
679 	.set_rate = rv3032_clkout_set_rate,
680 };
681 
682 static int rv3032_clkout_register_clk(struct rv3032_data *rv3032,
683 				      struct i2c_client *client)
684 {
685 	int ret;
686 	struct clk *clk;
687 	struct clk_init_data init;
688 	struct device_node *node = client->dev.of_node;
689 
690 	ret = regmap_update_bits(rv3032->regmap, RV3032_TLSB, RV3032_TLSB_CLKF, 0);
691 	if (ret < 0)
692 		return ret;
693 
694 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2, RV3032_CTRL2_CLKIE, 0);
695 	if (ret < 0)
696 		return ret;
697 
698 	ret = regmap_write(rv3032->regmap, RV3032_CLK_IRQ, 0);
699 	if (ret < 0)
700 		return ret;
701 
702 	init.name = "rv3032-clkout";
703 	init.ops = &rv3032_clkout_ops;
704 	init.flags = 0;
705 	init.parent_names = NULL;
706 	init.num_parents = 0;
707 	rv3032->clkout_hw.init = &init;
708 
709 	of_property_read_string(node, "clock-output-names", &init.name);
710 
711 	clk = devm_clk_register(&client->dev, &rv3032->clkout_hw);
712 	if (!IS_ERR(clk))
713 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
714 
715 	return 0;
716 }
717 #endif
718 
719 static int rv3032_hwmon_read_temp(struct device *dev, long *mC)
720 {
721 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
722 	u8 buf[2];
723 	int temp, prev = 0;
724 	int ret;
725 
726 	ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
727 	if (ret)
728 		return ret;
729 
730 	temp = sign_extend32(buf[1], 7) << 4;
731 	temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
732 
733 	/* No blocking or shadowing on RV3032_TLSB and RV3032_TMSB */
734 	do {
735 		prev = temp;
736 
737 		ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
738 		if (ret)
739 			return ret;
740 
741 		temp = sign_extend32(buf[1], 7) << 4;
742 		temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
743 	} while (temp != prev);
744 
745 	*mC = (temp * 1000) / 16;
746 
747 	return 0;
748 }
749 
750 static umode_t rv3032_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
751 				       u32 attr, int channel)
752 {
753 	if (type != hwmon_temp)
754 		return 0;
755 
756 	switch (attr) {
757 	case hwmon_temp_input:
758 		return 0444;
759 	default:
760 		return 0;
761 	}
762 }
763 
764 static int rv3032_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
765 			     u32 attr, int channel, long *temp)
766 {
767 	int err;
768 
769 	switch (attr) {
770 	case hwmon_temp_input:
771 		err = rv3032_hwmon_read_temp(dev, temp);
772 		break;
773 	default:
774 		err = -EOPNOTSUPP;
775 		break;
776 	}
777 
778 	return err;
779 }
780 
781 static const struct hwmon_channel_info *rv3032_hwmon_info[] = {
782 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
783 	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
784 	NULL
785 };
786 
787 static const struct hwmon_ops rv3032_hwmon_hwmon_ops = {
788 	.is_visible = rv3032_hwmon_is_visible,
789 	.read = rv3032_hwmon_read,
790 };
791 
792 static const struct hwmon_chip_info rv3032_hwmon_chip_info = {
793 	.ops = &rv3032_hwmon_hwmon_ops,
794 	.info = rv3032_hwmon_info,
795 };
796 
797 static void rv3032_hwmon_register(struct device *dev)
798 {
799 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
800 
801 	if (!IS_REACHABLE(CONFIG_HWMON))
802 		return;
803 
804 	devm_hwmon_device_register_with_info(dev, "rv3032", rv3032, &rv3032_hwmon_chip_info, NULL);
805 }
806 
807 static const struct rtc_class_ops rv3032_rtc_ops = {
808 	.read_time = rv3032_get_time,
809 	.set_time = rv3032_set_time,
810 	.read_offset = rv3032_read_offset,
811 	.set_offset = rv3032_set_offset,
812 	.ioctl = rv3032_ioctl,
813 	.read_alarm = rv3032_get_alarm,
814 	.set_alarm = rv3032_set_alarm,
815 	.alarm_irq_enable = rv3032_alarm_irq_enable,
816 };
817 
818 static const struct regmap_config regmap_config = {
819 	.reg_bits = 8,
820 	.val_bits = 8,
821 	.max_register = 0xCA,
822 };
823 
824 static int rv3032_probe(struct i2c_client *client)
825 {
826 	struct rv3032_data *rv3032;
827 	int ret, status;
828 	struct nvmem_config nvmem_cfg = {
829 		.name = "rv3032_nvram",
830 		.word_size = 1,
831 		.stride = 1,
832 		.size = 16,
833 		.type = NVMEM_TYPE_BATTERY_BACKED,
834 		.reg_read = rv3032_nvram_read,
835 		.reg_write = rv3032_nvram_write,
836 	};
837 	struct nvmem_config eeprom_cfg = {
838 		.name = "rv3032_eeprom",
839 		.word_size = 1,
840 		.stride = 1,
841 		.size = 32,
842 		.type = NVMEM_TYPE_EEPROM,
843 		.reg_read = rv3032_eeprom_read,
844 		.reg_write = rv3032_eeprom_write,
845 	};
846 
847 	rv3032 = devm_kzalloc(&client->dev, sizeof(struct rv3032_data),
848 			      GFP_KERNEL);
849 	if (!rv3032)
850 		return -ENOMEM;
851 
852 	rv3032->regmap = devm_regmap_init_i2c(client, &regmap_config);
853 	if (IS_ERR(rv3032->regmap))
854 		return PTR_ERR(rv3032->regmap);
855 
856 	i2c_set_clientdata(client, rv3032);
857 
858 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
859 	if (ret < 0)
860 		return ret;
861 
862 	rv3032->rtc = devm_rtc_allocate_device(&client->dev);
863 	if (IS_ERR(rv3032->rtc))
864 		return PTR_ERR(rv3032->rtc);
865 
866 	if (client->irq > 0) {
867 		ret = devm_request_threaded_irq(&client->dev, client->irq,
868 						NULL, rv3032_handle_irq,
869 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
870 						"rv3032", rv3032);
871 		if (ret) {
872 			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
873 			client->irq = 0;
874 		}
875 	}
876 	if (!client->irq)
877 		clear_bit(RTC_FEATURE_ALARM, rv3032->rtc->features);
878 
879 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
880 				 RV3032_CTRL1_WADA, RV3032_CTRL1_WADA);
881 	if (ret)
882 		return ret;
883 
884 	rv3032_trickle_charger_setup(&client->dev, rv3032);
885 
886 	rv3032->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
887 	rv3032->rtc->range_max = RTC_TIMESTAMP_END_2099;
888 	rv3032->rtc->ops = &rv3032_rtc_ops;
889 	ret = devm_rtc_register_device(rv3032->rtc);
890 	if (ret)
891 		return ret;
892 
893 	nvmem_cfg.priv = rv3032->regmap;
894 	devm_rtc_nvmem_register(rv3032->rtc, &nvmem_cfg);
895 	eeprom_cfg.priv = rv3032;
896 	devm_rtc_nvmem_register(rv3032->rtc, &eeprom_cfg);
897 
898 	rv3032->rtc->max_user_freq = 1;
899 
900 #ifdef CONFIG_COMMON_CLK
901 	rv3032_clkout_register_clk(rv3032, client);
902 #endif
903 
904 	rv3032_hwmon_register(&client->dev);
905 
906 	return 0;
907 }
908 
909 static const __maybe_unused struct of_device_id rv3032_of_match[] = {
910 	{ .compatible = "microcrystal,rv3032", },
911 	{ }
912 };
913 MODULE_DEVICE_TABLE(of, rv3032_of_match);
914 
915 static struct i2c_driver rv3032_driver = {
916 	.driver = {
917 		.name = "rtc-rv3032",
918 		.of_match_table = of_match_ptr(rv3032_of_match),
919 	},
920 	.probe_new	= rv3032_probe,
921 };
922 module_i2c_driver(rv3032_driver);
923 
924 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
925 MODULE_DESCRIPTION("Micro Crystal RV3032 RTC driver");
926 MODULE_LICENSE("GPL v2");
927