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 	bool trickle_charger_set;
110 #ifdef CONFIG_COMMON_CLK
111 	struct clk_hw clkout_hw;
112 #endif
113 };
114 
115 static u16 rv3032_trickle_resistors[] = {1000, 2000, 7000, 11000};
116 static u16 rv3032_trickle_voltages[] = {0, 1750, 3000, 4400};
117 
rv3032_exit_eerd(struct rv3032_data * rv3032,u32 eerd)118 static int rv3032_exit_eerd(struct rv3032_data *rv3032, u32 eerd)
119 {
120 	if (eerd)
121 		return 0;
122 
123 	return regmap_update_bits(rv3032->regmap, RV3032_CTRL1, RV3032_CTRL1_EERD, 0);
124 }
125 
rv3032_enter_eerd(struct rv3032_data * rv3032,u32 * eerd)126 static int rv3032_enter_eerd(struct rv3032_data *rv3032, u32 *eerd)
127 {
128 	u32 ctrl1, status;
129 	int ret;
130 
131 	ret = regmap_read(rv3032->regmap, RV3032_CTRL1, &ctrl1);
132 	if (ret)
133 		return ret;
134 
135 	*eerd = ctrl1 & RV3032_CTRL1_EERD;
136 	if (*eerd)
137 		return 0;
138 
139 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
140 				 RV3032_CTRL1_EERD, RV3032_CTRL1_EERD);
141 	if (ret)
142 		return ret;
143 
144 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
145 				       !(status & RV3032_TLSB_EEBUSY),
146 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
147 	if (ret) {
148 		rv3032_exit_eerd(rv3032, *eerd);
149 
150 		return ret;
151 	}
152 
153 	return 0;
154 }
155 
rv3032_update_cfg(struct rv3032_data * rv3032,unsigned int reg,unsigned int mask,unsigned int val)156 static int rv3032_update_cfg(struct rv3032_data *rv3032, unsigned int reg,
157 			     unsigned int mask, unsigned int val)
158 {
159 	u32 status, eerd;
160 	int ret;
161 
162 	ret = rv3032_enter_eerd(rv3032, &eerd);
163 	if (ret)
164 		return ret;
165 
166 	ret = regmap_update_bits(rv3032->regmap, reg, mask, val);
167 	if (ret)
168 		goto exit_eerd;
169 
170 	ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
171 	if (ret)
172 		goto exit_eerd;
173 
174 	usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
175 
176 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
177 				       !(status & RV3032_TLSB_EEBUSY),
178 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
179 
180 exit_eerd:
181 	rv3032_exit_eerd(rv3032, eerd);
182 
183 	return ret;
184 }
185 
rv3032_handle_irq(int irq,void * dev_id)186 static irqreturn_t rv3032_handle_irq(int irq, void *dev_id)
187 {
188 	struct rv3032_data *rv3032 = dev_id;
189 	unsigned long events = 0;
190 	u32 status = 0, ctrl = 0;
191 
192 	if (regmap_read(rv3032->regmap, RV3032_STATUS, &status) < 0 ||
193 	    status == 0) {
194 		return IRQ_NONE;
195 	}
196 
197 	if (status & RV3032_STATUS_TF) {
198 		status |= RV3032_STATUS_TF;
199 		ctrl |= RV3032_CTRL2_TIE;
200 		events |= RTC_PF;
201 	}
202 
203 	if (status & RV3032_STATUS_AF) {
204 		status |= RV3032_STATUS_AF;
205 		ctrl |= RV3032_CTRL2_AIE;
206 		events |= RTC_AF;
207 	}
208 
209 	if (status & RV3032_STATUS_UF) {
210 		status |= RV3032_STATUS_UF;
211 		ctrl |= RV3032_CTRL2_UIE;
212 		events |= RTC_UF;
213 	}
214 
215 	if (events) {
216 		rtc_update_irq(rv3032->rtc, 1, events);
217 		regmap_update_bits(rv3032->regmap, RV3032_STATUS, status, 0);
218 		regmap_update_bits(rv3032->regmap, RV3032_CTRL2, ctrl, 0);
219 	}
220 
221 	return IRQ_HANDLED;
222 }
223 
rv3032_get_time(struct device * dev,struct rtc_time * tm)224 static int rv3032_get_time(struct device *dev, struct rtc_time *tm)
225 {
226 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
227 	u8 date[7];
228 	int ret, status;
229 
230 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
231 	if (ret < 0)
232 		return ret;
233 
234 	if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
235 		return -EINVAL;
236 
237 	ret = regmap_bulk_read(rv3032->regmap, RV3032_SEC, date, sizeof(date));
238 	if (ret)
239 		return ret;
240 
241 	tm->tm_sec  = bcd2bin(date[0] & 0x7f);
242 	tm->tm_min  = bcd2bin(date[1] & 0x7f);
243 	tm->tm_hour = bcd2bin(date[2] & 0x3f);
244 	tm->tm_wday = date[3] & 0x7;
245 	tm->tm_mday = bcd2bin(date[4] & 0x3f);
246 	tm->tm_mon  = bcd2bin(date[5] & 0x1f) - 1;
247 	tm->tm_year = bcd2bin(date[6]) + 100;
248 
249 	return 0;
250 }
251 
rv3032_set_time(struct device * dev,struct rtc_time * tm)252 static int rv3032_set_time(struct device *dev, struct rtc_time *tm)
253 {
254 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
255 	u8 date[7];
256 	int ret;
257 
258 	date[0] = bin2bcd(tm->tm_sec);
259 	date[1] = bin2bcd(tm->tm_min);
260 	date[2] = bin2bcd(tm->tm_hour);
261 	date[3] = tm->tm_wday;
262 	date[4] = bin2bcd(tm->tm_mday);
263 	date[5] = bin2bcd(tm->tm_mon + 1);
264 	date[6] = bin2bcd(tm->tm_year - 100);
265 
266 	ret = regmap_bulk_write(rv3032->regmap, RV3032_SEC, date,
267 				sizeof(date));
268 	if (ret)
269 		return ret;
270 
271 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
272 				 RV3032_STATUS_PORF | RV3032_STATUS_VLF, 0);
273 
274 	return ret;
275 }
276 
rv3032_get_alarm(struct device * dev,struct rtc_wkalrm * alrm)277 static int rv3032_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
278 {
279 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
280 	u8 alarmvals[3];
281 	int status, ctrl, ret;
282 
283 	ret = regmap_bulk_read(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
284 			       sizeof(alarmvals));
285 	if (ret)
286 		return ret;
287 
288 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
289 	if (ret < 0)
290 		return ret;
291 
292 	ret = regmap_read(rv3032->regmap, RV3032_CTRL2, &ctrl);
293 	if (ret < 0)
294 		return ret;
295 
296 	alrm->time.tm_sec  = 0;
297 	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
298 	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
299 	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
300 
301 	alrm->enabled = !!(ctrl & RV3032_CTRL2_AIE);
302 	alrm->pending = (status & RV3032_STATUS_AF) && alrm->enabled;
303 
304 	return 0;
305 }
306 
rv3032_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)307 static int rv3032_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
308 {
309 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
310 	u8 alarmvals[3];
311 	u8 ctrl = 0;
312 	int ret;
313 
314 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
315 				 RV3032_CTRL2_AIE | RV3032_CTRL2_UIE, 0);
316 	if (ret)
317 		return ret;
318 
319 	alarmvals[0] = bin2bcd(alrm->time.tm_min);
320 	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
321 	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
322 
323 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
324 				 RV3032_STATUS_AF, 0);
325 	if (ret)
326 		return ret;
327 
328 	ret = regmap_bulk_write(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
329 				sizeof(alarmvals));
330 	if (ret)
331 		return ret;
332 
333 	if (alrm->enabled) {
334 		if (rv3032->rtc->uie_rtctimer.enabled)
335 			ctrl |= RV3032_CTRL2_UIE;
336 		if (rv3032->rtc->aie_timer.enabled)
337 			ctrl |= RV3032_CTRL2_AIE;
338 	}
339 
340 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
341 				 RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
342 
343 	return ret;
344 }
345 
rv3032_alarm_irq_enable(struct device * dev,unsigned int enabled)346 static int rv3032_alarm_irq_enable(struct device *dev, unsigned int enabled)
347 {
348 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
349 	int ctrl = 0, ret;
350 
351 	if (enabled) {
352 		if (rv3032->rtc->uie_rtctimer.enabled)
353 			ctrl |= RV3032_CTRL2_UIE;
354 		if (rv3032->rtc->aie_timer.enabled)
355 			ctrl |= RV3032_CTRL2_AIE;
356 	}
357 
358 	ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
359 				 RV3032_STATUS_AF | RV3032_STATUS_UF, 0);
360 	if (ret)
361 		return ret;
362 
363 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
364 				 RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
365 	if (ret)
366 		return ret;
367 
368 	return 0;
369 }
370 
rv3032_read_offset(struct device * dev,long * offset)371 static int rv3032_read_offset(struct device *dev, long *offset)
372 {
373 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
374 	int ret, value, steps;
375 
376 	ret = regmap_read(rv3032->regmap, RV3032_OFFSET, &value);
377 	if (ret < 0)
378 		return ret;
379 
380 	steps = sign_extend32(FIELD_GET(RV3032_OFFSET_MSK, value), 5);
381 
382 	*offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
383 
384 	return 0;
385 }
386 
rv3032_set_offset(struct device * dev,long offset)387 static int rv3032_set_offset(struct device *dev, long offset)
388 {
389 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
390 
391 	offset = clamp(offset, -7629L, 7391L) * 1000;
392 	offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
393 
394 	return rv3032_update_cfg(rv3032, RV3032_OFFSET, RV3032_OFFSET_MSK,
395 				 FIELD_PREP(RV3032_OFFSET_MSK, offset));
396 }
397 
rv3032_param_get(struct device * dev,struct rtc_param * param)398 static int rv3032_param_get(struct device *dev, struct rtc_param *param)
399 {
400 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
401 	int ret;
402 
403 	switch(param->param) {
404 		u32 value;
405 
406 	case RTC_PARAM_BACKUP_SWITCH_MODE:
407 		ret = regmap_read(rv3032->regmap, RV3032_PMU, &value);
408 		if (ret < 0)
409 			return ret;
410 
411 		value = FIELD_GET(RV3032_PMU_BSM, value);
412 
413 		switch(value) {
414 		case RV3032_PMU_BSM_DSM:
415 			param->uvalue = RTC_BSM_DIRECT;
416 			break;
417 		case RV3032_PMU_BSM_LSM:
418 			param->uvalue = RTC_BSM_LEVEL;
419 			break;
420 		default:
421 			param->uvalue = RTC_BSM_DISABLED;
422 		}
423 
424 		break;
425 
426 	default:
427 		return -EINVAL;
428 	}
429 
430 	return 0;
431 }
432 
rv3032_param_set(struct device * dev,struct rtc_param * param)433 static int rv3032_param_set(struct device *dev, struct rtc_param *param)
434 {
435 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
436 
437 	switch(param->param) {
438 		u8 mode;
439 	case RTC_PARAM_BACKUP_SWITCH_MODE:
440 		if (rv3032->trickle_charger_set)
441 			return -EINVAL;
442 
443 		switch (param->uvalue) {
444 		case RTC_BSM_DISABLED:
445 			mode = 0;
446 			break;
447 		case RTC_BSM_DIRECT:
448 			mode = RV3032_PMU_BSM_DSM;
449 			break;
450 		case RTC_BSM_LEVEL:
451 			mode = RV3032_PMU_BSM_LSM;
452 			break;
453 		default:
454 			return -EINVAL;
455 		}
456 
457 		return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_BSM,
458 					 FIELD_PREP(RV3032_PMU_BSM, mode));
459 
460 	default:
461 		return -EINVAL;
462 	}
463 
464 	return 0;
465 }
466 
rv3032_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)467 static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
468 {
469 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
470 	int status, val = 0, ret = 0;
471 
472 	switch (cmd) {
473 	case RTC_VL_READ:
474 		ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
475 		if (ret < 0)
476 			return ret;
477 
478 		if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
479 			val = RTC_VL_DATA_INVALID;
480 		return put_user(val, (unsigned int __user *)arg);
481 
482 	default:
483 		return -ENOIOCTLCMD;
484 	}
485 }
486 
rv3032_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)487 static int rv3032_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes)
488 {
489 	return regmap_bulk_write(priv, RV3032_RAM1 + offset, val, bytes);
490 }
491 
rv3032_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)492 static int rv3032_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes)
493 {
494 	return regmap_bulk_read(priv, RV3032_RAM1 + offset, val, bytes);
495 }
496 
rv3032_eeprom_write(void * priv,unsigned int offset,void * val,size_t bytes)497 static int rv3032_eeprom_write(void *priv, unsigned int offset, void *val, size_t bytes)
498 {
499 	struct rv3032_data *rv3032 = priv;
500 	u32 status, eerd;
501 	int i, ret;
502 	u8 *buf = val;
503 
504 	ret = rv3032_enter_eerd(rv3032, &eerd);
505 	if (ret)
506 		return ret;
507 
508 	for (i = 0; i < bytes; i++) {
509 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
510 				   RV3032_EEPROM_USER + offset + i);
511 		if (ret)
512 			goto exit_eerd;
513 
514 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_DATA, buf[i]);
515 		if (ret)
516 			goto exit_eerd;
517 
518 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
519 				   RV3032_EEPROM_CMD_WRITE);
520 		if (ret)
521 			goto exit_eerd;
522 
523 		usleep_range(RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
524 
525 		ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
526 					       !(status & RV3032_TLSB_EEBUSY),
527 					       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
528 		if (ret)
529 			goto exit_eerd;
530 	}
531 
532 exit_eerd:
533 	rv3032_exit_eerd(rv3032, eerd);
534 
535 	return ret;
536 }
537 
rv3032_eeprom_read(void * priv,unsigned int offset,void * val,size_t bytes)538 static int rv3032_eeprom_read(void *priv, unsigned int offset, void *val, size_t bytes)
539 {
540 	struct rv3032_data *rv3032 = priv;
541 	u32 status, eerd, data;
542 	int i, ret;
543 	u8 *buf = val;
544 
545 	ret = rv3032_enter_eerd(rv3032, &eerd);
546 	if (ret)
547 		return ret;
548 
549 	for (i = 0; i < bytes; i++) {
550 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
551 				   RV3032_EEPROM_USER + offset + i);
552 		if (ret)
553 			goto exit_eerd;
554 
555 		ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
556 				   RV3032_EEPROM_CMD_READ);
557 		if (ret)
558 			goto exit_eerd;
559 
560 		ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
561 					       !(status & RV3032_TLSB_EEBUSY),
562 					       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
563 		if (ret)
564 			goto exit_eerd;
565 
566 		ret = regmap_read(rv3032->regmap, RV3032_EEPROM_DATA, &data);
567 		if (ret)
568 			goto exit_eerd;
569 		buf[i] = data;
570 	}
571 
572 exit_eerd:
573 	rv3032_exit_eerd(rv3032, eerd);
574 
575 	return ret;
576 }
577 
rv3032_trickle_charger_setup(struct device * dev,struct rv3032_data * rv3032)578 static int rv3032_trickle_charger_setup(struct device *dev, struct rv3032_data *rv3032)
579 {
580 	u32 val, ohms, voltage;
581 	int i;
582 
583 	val = FIELD_PREP(RV3032_PMU_TCM, 1) | FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_DSM);
584 	if (!device_property_read_u32(dev, "trickle-voltage-millivolt", &voltage)) {
585 		for (i = 0; i < ARRAY_SIZE(rv3032_trickle_voltages); i++)
586 			if (voltage == rv3032_trickle_voltages[i])
587 				break;
588 		if (i < ARRAY_SIZE(rv3032_trickle_voltages))
589 			val = FIELD_PREP(RV3032_PMU_TCM, i) |
590 			      FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_LSM);
591 	}
592 
593 	if (device_property_read_u32(dev, "trickle-resistor-ohms", &ohms))
594 		return 0;
595 
596 	for (i = 0; i < ARRAY_SIZE(rv3032_trickle_resistors); i++)
597 		if (ohms == rv3032_trickle_resistors[i])
598 			break;
599 
600 	if (i >= ARRAY_SIZE(rv3032_trickle_resistors)) {
601 		dev_warn(dev, "invalid trickle resistor value\n");
602 
603 		return 0;
604 	}
605 
606 	rv3032->trickle_charger_set = true;
607 
608 	return rv3032_update_cfg(rv3032, RV3032_PMU,
609 				 RV3032_PMU_TCR | RV3032_PMU_TCM | RV3032_PMU_BSM,
610 				 val | FIELD_PREP(RV3032_PMU_TCR, i));
611 }
612 
613 #ifdef CONFIG_COMMON_CLK
614 #define clkout_hw_to_rv3032(hw) container_of(hw, struct rv3032_data, clkout_hw)
615 
616 static int clkout_xtal_rates[] = {
617 	32768,
618 	1024,
619 	64,
620 	1,
621 };
622 
623 #define RV3032_HFD_STEP 8192
624 
rv3032_clkout_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)625 static unsigned long rv3032_clkout_recalc_rate(struct clk_hw *hw,
626 					       unsigned long parent_rate)
627 {
628 	int clkout, ret;
629 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
630 
631 	ret = regmap_read(rv3032->regmap, RV3032_CLKOUT2, &clkout);
632 	if (ret < 0)
633 		return 0;
634 
635 	if (clkout & RV3032_CLKOUT2_OS) {
636 		unsigned long rate = FIELD_GET(RV3032_CLKOUT2_HFD_MSK, clkout) << 8;
637 
638 		ret = regmap_read(rv3032->regmap, RV3032_CLKOUT1, &clkout);
639 		if (ret < 0)
640 			return 0;
641 
642 		rate += clkout + 1;
643 
644 		return rate * RV3032_HFD_STEP;
645 	}
646 
647 	return clkout_xtal_rates[FIELD_GET(RV3032_CLKOUT2_FD_MSK, clkout)];
648 }
649 
rv3032_clkout_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)650 static long rv3032_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
651 				     unsigned long *prate)
652 {
653 	int i, hfd;
654 
655 	if (rate < RV3032_HFD_STEP)
656 		for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++)
657 			if (clkout_xtal_rates[i] <= rate)
658 				return clkout_xtal_rates[i];
659 
660 	hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
661 
662 	return RV3032_HFD_STEP * clamp(hfd, 0, 8192);
663 }
664 
rv3032_clkout_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)665 static int rv3032_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
666 				  unsigned long parent_rate)
667 {
668 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
669 	u32 status, eerd;
670 	int i, hfd, ret;
671 
672 	for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++) {
673 		if (clkout_xtal_rates[i] == rate) {
674 			return rv3032_update_cfg(rv3032, RV3032_CLKOUT2, 0xff,
675 						 FIELD_PREP(RV3032_CLKOUT2_FD_MSK, i));
676 		}
677 	}
678 
679 	hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
680 	hfd = clamp(hfd, 1, 8192) - 1;
681 
682 	ret = rv3032_enter_eerd(rv3032, &eerd);
683 	if (ret)
684 		return ret;
685 
686 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT1, hfd & 0xff);
687 	if (ret)
688 		goto exit_eerd;
689 
690 	ret = regmap_write(rv3032->regmap, RV3032_CLKOUT2, RV3032_CLKOUT2_OS |
691 			    FIELD_PREP(RV3032_CLKOUT2_HFD_MSK, hfd >> 8));
692 	if (ret)
693 		goto exit_eerd;
694 
695 	ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
696 	if (ret)
697 		goto exit_eerd;
698 
699 	usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
700 
701 	ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
702 				       !(status & RV3032_TLSB_EEBUSY),
703 				       RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
704 
705 exit_eerd:
706 	rv3032_exit_eerd(rv3032, eerd);
707 
708 	return ret;
709 }
710 
rv3032_clkout_prepare(struct clk_hw * hw)711 static int rv3032_clkout_prepare(struct clk_hw *hw)
712 {
713 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
714 
715 	return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, 0);
716 }
717 
rv3032_clkout_unprepare(struct clk_hw * hw)718 static void rv3032_clkout_unprepare(struct clk_hw *hw)
719 {
720 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
721 
722 	rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, RV3032_PMU_NCLKE);
723 }
724 
rv3032_clkout_is_prepared(struct clk_hw * hw)725 static int rv3032_clkout_is_prepared(struct clk_hw *hw)
726 {
727 	int val, ret;
728 	struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
729 
730 	ret = regmap_read(rv3032->regmap, RV3032_PMU, &val);
731 	if (ret < 0)
732 		return ret;
733 
734 	return !(val & RV3032_PMU_NCLKE);
735 }
736 
737 static const struct clk_ops rv3032_clkout_ops = {
738 	.prepare = rv3032_clkout_prepare,
739 	.unprepare = rv3032_clkout_unprepare,
740 	.is_prepared = rv3032_clkout_is_prepared,
741 	.recalc_rate = rv3032_clkout_recalc_rate,
742 	.round_rate = rv3032_clkout_round_rate,
743 	.set_rate = rv3032_clkout_set_rate,
744 };
745 
rv3032_clkout_register_clk(struct rv3032_data * rv3032,struct i2c_client * client)746 static int rv3032_clkout_register_clk(struct rv3032_data *rv3032,
747 				      struct i2c_client *client)
748 {
749 	int ret;
750 	struct clk *clk;
751 	struct clk_init_data init;
752 	struct device_node *node = client->dev.of_node;
753 
754 	ret = regmap_update_bits(rv3032->regmap, RV3032_TLSB, RV3032_TLSB_CLKF, 0);
755 	if (ret < 0)
756 		return ret;
757 
758 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2, RV3032_CTRL2_CLKIE, 0);
759 	if (ret < 0)
760 		return ret;
761 
762 	ret = regmap_write(rv3032->regmap, RV3032_CLK_IRQ, 0);
763 	if (ret < 0)
764 		return ret;
765 
766 	init.name = "rv3032-clkout";
767 	init.ops = &rv3032_clkout_ops;
768 	init.flags = 0;
769 	init.parent_names = NULL;
770 	init.num_parents = 0;
771 	rv3032->clkout_hw.init = &init;
772 
773 	of_property_read_string(node, "clock-output-names", &init.name);
774 
775 	clk = devm_clk_register(&client->dev, &rv3032->clkout_hw);
776 	if (!IS_ERR(clk))
777 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
778 
779 	return 0;
780 }
781 #endif
782 
rv3032_hwmon_read_temp(struct device * dev,long * mC)783 static int rv3032_hwmon_read_temp(struct device *dev, long *mC)
784 {
785 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
786 	u8 buf[2];
787 	int temp, prev = 0;
788 	int ret;
789 
790 	ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
791 	if (ret)
792 		return ret;
793 
794 	temp = sign_extend32(buf[1], 7) << 4;
795 	temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
796 
797 	/* No blocking or shadowing on RV3032_TLSB and RV3032_TMSB */
798 	do {
799 		prev = temp;
800 
801 		ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
802 		if (ret)
803 			return ret;
804 
805 		temp = sign_extend32(buf[1], 7) << 4;
806 		temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
807 	} while (temp != prev);
808 
809 	*mC = (temp * 1000) / 16;
810 
811 	return 0;
812 }
813 
rv3032_hwmon_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)814 static umode_t rv3032_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
815 				       u32 attr, int channel)
816 {
817 	if (type != hwmon_temp)
818 		return 0;
819 
820 	switch (attr) {
821 	case hwmon_temp_input:
822 		return 0444;
823 	default:
824 		return 0;
825 	}
826 }
827 
rv3032_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * temp)828 static int rv3032_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
829 			     u32 attr, int channel, long *temp)
830 {
831 	int err;
832 
833 	switch (attr) {
834 	case hwmon_temp_input:
835 		err = rv3032_hwmon_read_temp(dev, temp);
836 		break;
837 	default:
838 		err = -EOPNOTSUPP;
839 		break;
840 	}
841 
842 	return err;
843 }
844 
845 static const struct hwmon_channel_info *rv3032_hwmon_info[] = {
846 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
847 	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
848 	NULL
849 };
850 
851 static const struct hwmon_ops rv3032_hwmon_hwmon_ops = {
852 	.is_visible = rv3032_hwmon_is_visible,
853 	.read = rv3032_hwmon_read,
854 };
855 
856 static const struct hwmon_chip_info rv3032_hwmon_chip_info = {
857 	.ops = &rv3032_hwmon_hwmon_ops,
858 	.info = rv3032_hwmon_info,
859 };
860 
rv3032_hwmon_register(struct device * dev)861 static void rv3032_hwmon_register(struct device *dev)
862 {
863 	struct rv3032_data *rv3032 = dev_get_drvdata(dev);
864 
865 	if (!IS_REACHABLE(CONFIG_HWMON))
866 		return;
867 
868 	devm_hwmon_device_register_with_info(dev, "rv3032", rv3032, &rv3032_hwmon_chip_info, NULL);
869 }
870 
871 static const struct rtc_class_ops rv3032_rtc_ops = {
872 	.read_time = rv3032_get_time,
873 	.set_time = rv3032_set_time,
874 	.read_offset = rv3032_read_offset,
875 	.set_offset = rv3032_set_offset,
876 	.ioctl = rv3032_ioctl,
877 	.read_alarm = rv3032_get_alarm,
878 	.set_alarm = rv3032_set_alarm,
879 	.alarm_irq_enable = rv3032_alarm_irq_enable,
880 	.param_get = rv3032_param_get,
881 	.param_set = rv3032_param_set,
882 };
883 
884 static const struct regmap_config regmap_config = {
885 	.reg_bits = 8,
886 	.val_bits = 8,
887 	.max_register = 0xCA,
888 };
889 
rv3032_probe(struct i2c_client * client)890 static int rv3032_probe(struct i2c_client *client)
891 {
892 	struct rv3032_data *rv3032;
893 	int ret, status;
894 	struct nvmem_config nvmem_cfg = {
895 		.name = "rv3032_nvram",
896 		.word_size = 1,
897 		.stride = 1,
898 		.size = 16,
899 		.type = NVMEM_TYPE_BATTERY_BACKED,
900 		.reg_read = rv3032_nvram_read,
901 		.reg_write = rv3032_nvram_write,
902 	};
903 	struct nvmem_config eeprom_cfg = {
904 		.name = "rv3032_eeprom",
905 		.word_size = 1,
906 		.stride = 1,
907 		.size = 32,
908 		.type = NVMEM_TYPE_EEPROM,
909 		.reg_read = rv3032_eeprom_read,
910 		.reg_write = rv3032_eeprom_write,
911 	};
912 
913 	rv3032 = devm_kzalloc(&client->dev, sizeof(struct rv3032_data),
914 			      GFP_KERNEL);
915 	if (!rv3032)
916 		return -ENOMEM;
917 
918 	rv3032->regmap = devm_regmap_init_i2c(client, &regmap_config);
919 	if (IS_ERR(rv3032->regmap))
920 		return PTR_ERR(rv3032->regmap);
921 
922 	i2c_set_clientdata(client, rv3032);
923 
924 	ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
925 	if (ret < 0)
926 		return ret;
927 
928 	rv3032->rtc = devm_rtc_allocate_device(&client->dev);
929 	if (IS_ERR(rv3032->rtc))
930 		return PTR_ERR(rv3032->rtc);
931 
932 	if (client->irq > 0) {
933 		ret = devm_request_threaded_irq(&client->dev, client->irq,
934 						NULL, rv3032_handle_irq,
935 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
936 						"rv3032", rv3032);
937 		if (ret) {
938 			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
939 			client->irq = 0;
940 		}
941 	}
942 	if (!client->irq)
943 		clear_bit(RTC_FEATURE_ALARM, rv3032->rtc->features);
944 
945 	ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
946 				 RV3032_CTRL1_WADA, RV3032_CTRL1_WADA);
947 	if (ret)
948 		return ret;
949 
950 	rv3032_trickle_charger_setup(&client->dev, rv3032);
951 
952 	set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3032->rtc->features);
953 	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rv3032->rtc->features);
954 
955 	rv3032->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
956 	rv3032->rtc->range_max = RTC_TIMESTAMP_END_2099;
957 	rv3032->rtc->ops = &rv3032_rtc_ops;
958 	ret = devm_rtc_register_device(rv3032->rtc);
959 	if (ret)
960 		return ret;
961 
962 	nvmem_cfg.priv = rv3032->regmap;
963 	devm_rtc_nvmem_register(rv3032->rtc, &nvmem_cfg);
964 	eeprom_cfg.priv = rv3032;
965 	devm_rtc_nvmem_register(rv3032->rtc, &eeprom_cfg);
966 
967 	rv3032->rtc->max_user_freq = 1;
968 
969 #ifdef CONFIG_COMMON_CLK
970 	rv3032_clkout_register_clk(rv3032, client);
971 #endif
972 
973 	rv3032_hwmon_register(&client->dev);
974 
975 	return 0;
976 }
977 
978 static const __maybe_unused struct of_device_id rv3032_of_match[] = {
979 	{ .compatible = "microcrystal,rv3032", },
980 	{ }
981 };
982 MODULE_DEVICE_TABLE(of, rv3032_of_match);
983 
984 static struct i2c_driver rv3032_driver = {
985 	.driver = {
986 		.name = "rtc-rv3032",
987 		.of_match_table = of_match_ptr(rv3032_of_match),
988 	},
989 	.probe_new	= rv3032_probe,
990 };
991 module_i2c_driver(rv3032_driver);
992 
993 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
994 MODULE_DESCRIPTION("Micro Crystal RV3032 RTC driver");
995 MODULE_LICENSE("GPL v2");
996