xref: /openbmc/linux/drivers/rtc/rtc-rv3029c2.c (revision 1d1997db)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Micro Crystal RV-3029 / RV-3049 rtc class driver
4  *
5  * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
6  *         Michael Buesch <m@bues.ch>
7  *
8  * based on previously existing rtc class drivers
9  */
10 
11 #include <linux/module.h>
12 #include <linux/i2c.h>
13 #include <linux/spi/spi.h>
14 #include <linux/bcd.h>
15 #include <linux/rtc.h>
16 #include <linux/delay.h>
17 #include <linux/of.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/regmap.h>
21 
22 /* Register map */
23 /* control section */
24 #define RV3029_ONOFF_CTRL		0x00
25 #define RV3029_ONOFF_CTRL_WE		BIT(0)
26 #define RV3029_ONOFF_CTRL_TE		BIT(1)
27 #define RV3029_ONOFF_CTRL_TAR		BIT(2)
28 #define RV3029_ONOFF_CTRL_EERE		BIT(3)
29 #define RV3029_ONOFF_CTRL_SRON		BIT(4)
30 #define RV3029_ONOFF_CTRL_TD0		BIT(5)
31 #define RV3029_ONOFF_CTRL_TD1		BIT(6)
32 #define RV3029_ONOFF_CTRL_CLKINT	BIT(7)
33 #define RV3029_IRQ_CTRL			0x01
34 #define RV3029_IRQ_CTRL_AIE		BIT(0)
35 #define RV3029_IRQ_CTRL_TIE		BIT(1)
36 #define RV3029_IRQ_CTRL_V1IE		BIT(2)
37 #define RV3029_IRQ_CTRL_V2IE		BIT(3)
38 #define RV3029_IRQ_CTRL_SRIE		BIT(4)
39 #define RV3029_IRQ_FLAGS		0x02
40 #define RV3029_IRQ_FLAGS_AF		BIT(0)
41 #define RV3029_IRQ_FLAGS_TF		BIT(1)
42 #define RV3029_IRQ_FLAGS_V1IF		BIT(2)
43 #define RV3029_IRQ_FLAGS_V2IF		BIT(3)
44 #define RV3029_IRQ_FLAGS_SRF		BIT(4)
45 #define RV3029_STATUS			0x03
46 #define RV3029_STATUS_VLOW1		BIT(2)
47 #define RV3029_STATUS_VLOW2		BIT(3)
48 #define RV3029_STATUS_SR		BIT(4)
49 #define RV3029_STATUS_PON		BIT(5)
50 #define RV3029_STATUS_EEBUSY		BIT(7)
51 #define RV3029_RST_CTRL			0x04
52 #define RV3029_RST_CTRL_SYSR		BIT(4)
53 #define RV3029_CONTROL_SECTION_LEN	0x05
54 
55 /* watch section */
56 #define RV3029_W_SEC			0x08
57 #define RV3029_W_MINUTES		0x09
58 #define RV3029_W_HOURS			0x0A
59 #define RV3029_REG_HR_12_24		BIT(6) /* 24h/12h mode */
60 #define RV3029_REG_HR_PM		BIT(5) /* PM/AM bit in 12h mode */
61 #define RV3029_W_DATE			0x0B
62 #define RV3029_W_DAYS			0x0C
63 #define RV3029_W_MONTHS			0x0D
64 #define RV3029_W_YEARS			0x0E
65 #define RV3029_WATCH_SECTION_LEN	0x07
66 
67 /* alarm section */
68 #define RV3029_A_SC			0x10
69 #define RV3029_A_MN			0x11
70 #define RV3029_A_HR			0x12
71 #define RV3029_A_DT			0x13
72 #define RV3029_A_DW			0x14
73 #define RV3029_A_MO			0x15
74 #define RV3029_A_YR			0x16
75 #define RV3029_A_AE_X			BIT(7)
76 #define RV3029_ALARM_SECTION_LEN	0x07
77 
78 /* timer section */
79 #define RV3029_TIMER_LOW		0x18
80 #define RV3029_TIMER_HIGH		0x19
81 
82 /* temperature section */
83 #define RV3029_TEMP_PAGE		0x20
84 
85 /* eeprom data section */
86 #define RV3029_E2P_EEDATA1		0x28
87 #define RV3029_E2P_EEDATA2		0x29
88 #define RV3029_E2PDATA_SECTION_LEN	0x02
89 
90 /* eeprom control section */
91 #define RV3029_CONTROL_E2P_EECTRL	0x30
92 #define RV3029_EECTRL_THP		BIT(0) /* temp scan interval */
93 #define RV3029_EECTRL_THE		BIT(1) /* thermometer enable */
94 #define RV3029_EECTRL_FD0		BIT(2) /* CLKOUT */
95 #define RV3029_EECTRL_FD1		BIT(3) /* CLKOUT */
96 #define RV3029_TRICKLE_1K		BIT(4) /* 1.5K resistance */
97 #define RV3029_TRICKLE_5K		BIT(5) /* 5K   resistance */
98 #define RV3029_TRICKLE_20K		BIT(6) /* 20K  resistance */
99 #define RV3029_TRICKLE_80K		BIT(7) /* 80K  resistance */
100 #define RV3029_TRICKLE_MASK		(RV3029_TRICKLE_1K |\
101 					 RV3029_TRICKLE_5K |\
102 					 RV3029_TRICKLE_20K |\
103 					 RV3029_TRICKLE_80K)
104 #define RV3029_TRICKLE_SHIFT		4
105 #define RV3029_CONTROL_E2P_XOFFS	0x31 /* XTAL offset */
106 #define RV3029_CONTROL_E2P_XOFFS_SIGN	BIT(7) /* Sign: 1->pos, 0->neg */
107 #define RV3029_CONTROL_E2P_QCOEF	0x32 /* XTAL temp drift coef */
108 #define RV3029_CONTROL_E2P_TURNOVER	0x33 /* XTAL turnover temp (in *C) */
109 #define RV3029_CONTROL_E2P_TOV_MASK	0x3F /* XTAL turnover temp mask */
110 
111 /* user ram section */
112 #define RV3029_USR1_RAM_PAGE		0x38
113 #define RV3029_USR1_SECTION_LEN		0x04
114 #define RV3029_USR2_RAM_PAGE		0x3C
115 #define RV3029_USR2_SECTION_LEN		0x04
116 
117 struct rv3029_data {
118 	struct device		*dev;
119 	struct rtc_device	*rtc;
120 	struct regmap		*regmap;
121 	int irq;
122 };
123 
124 static int rv3029_read_regs(struct device *dev, u8 reg, u8 *buf,
125 			    unsigned int len)
126 {
127 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
128 
129 	if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
130 	    (reg + len > RV3029_USR1_RAM_PAGE + 8))
131 		return -EINVAL;
132 
133 	return regmap_bulk_read(rv3029->regmap, reg, buf, len);
134 }
135 
136 static int rv3029_write_regs(struct device *dev, u8 reg, u8 const buf[],
137 			     unsigned int len)
138 {
139 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
140 
141 	if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
142 	    (reg + len > RV3029_USR1_RAM_PAGE + 8))
143 		return -EINVAL;
144 
145 	return regmap_bulk_write(rv3029->regmap, reg, buf, len);
146 }
147 
148 static int rv3029_update_bits(struct device *dev, u8 reg, u8 mask, u8 set)
149 {
150 	u8 buf;
151 	int ret;
152 
153 	ret = rv3029_read_regs(dev, reg, &buf, 1);
154 	if (ret < 0)
155 		return ret;
156 	buf &= ~mask;
157 	buf |= set & mask;
158 	ret = rv3029_write_regs(dev, reg, &buf, 1);
159 	if (ret < 0)
160 		return ret;
161 
162 	return 0;
163 }
164 
165 static int rv3029_get_sr(struct device *dev, u8 *buf)
166 {
167 	int ret = rv3029_read_regs(dev, RV3029_STATUS, buf, 1);
168 
169 	if (ret < 0)
170 		return -EIO;
171 	dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
172 	return 0;
173 }
174 
175 static int rv3029_set_sr(struct device *dev, u8 val)
176 {
177 	u8 buf[1];
178 	int sr;
179 
180 	buf[0] = val;
181 	sr = rv3029_write_regs(dev, RV3029_STATUS, buf, 1);
182 	dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
183 	if (sr < 0)
184 		return -EIO;
185 	return 0;
186 }
187 
188 static int rv3029_eeprom_busywait(struct device *dev)
189 {
190 	int i, ret;
191 	u8 sr;
192 
193 	for (i = 100; i > 0; i--) {
194 		ret = rv3029_get_sr(dev, &sr);
195 		if (ret < 0)
196 			break;
197 		if (!(sr & RV3029_STATUS_EEBUSY))
198 			break;
199 		usleep_range(1000, 10000);
200 	}
201 	if (i <= 0) {
202 		dev_err(dev, "EEPROM busy wait timeout.\n");
203 		return -ETIMEDOUT;
204 	}
205 
206 	return ret;
207 }
208 
209 static int rv3029_eeprom_exit(struct device *dev)
210 {
211 	/* Re-enable eeprom refresh */
212 	return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
213 				  RV3029_ONOFF_CTRL_EERE,
214 				  RV3029_ONOFF_CTRL_EERE);
215 }
216 
217 static int rv3029_eeprom_enter(struct device *dev)
218 {
219 	int ret;
220 	u8 sr;
221 
222 	/* Check whether we are in the allowed voltage range. */
223 	ret = rv3029_get_sr(dev, &sr);
224 	if (ret < 0)
225 		return ret;
226 	if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
227 		/* We clear the bits and retry once just in case
228 		 * we had a brown out in early startup.
229 		 */
230 		sr &= ~RV3029_STATUS_VLOW1;
231 		sr &= ~RV3029_STATUS_VLOW2;
232 		ret = rv3029_set_sr(dev, sr);
233 		if (ret < 0)
234 			return ret;
235 		usleep_range(1000, 10000);
236 		ret = rv3029_get_sr(dev, &sr);
237 		if (ret < 0)
238 			return ret;
239 		if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
240 			dev_err(dev,
241 				"Supply voltage is too low to safely access the EEPROM.\n");
242 			return -ENODEV;
243 		}
244 	}
245 
246 	/* Disable eeprom refresh. */
247 	ret = rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE,
248 				 0);
249 	if (ret < 0)
250 		return ret;
251 
252 	/* Wait for any previous eeprom accesses to finish. */
253 	ret = rv3029_eeprom_busywait(dev);
254 	if (ret < 0)
255 		rv3029_eeprom_exit(dev);
256 
257 	return ret;
258 }
259 
260 static int rv3029_eeprom_read(struct device *dev, u8 reg,
261 			      u8 buf[], size_t len)
262 {
263 	int ret, err;
264 
265 	err = rv3029_eeprom_enter(dev);
266 	if (err < 0)
267 		return err;
268 
269 	ret = rv3029_read_regs(dev, reg, buf, len);
270 
271 	err = rv3029_eeprom_exit(dev);
272 	if (err < 0)
273 		return err;
274 
275 	return ret;
276 }
277 
278 static int rv3029_eeprom_write(struct device *dev, u8 reg,
279 			       u8 const buf[], size_t len)
280 {
281 	int ret, err;
282 	size_t i;
283 	u8 tmp;
284 
285 	err = rv3029_eeprom_enter(dev);
286 	if (err < 0)
287 		return err;
288 
289 	for (i = 0; i < len; i++, reg++) {
290 		ret = rv3029_read_regs(dev, reg, &tmp, 1);
291 		if (ret < 0)
292 			break;
293 		if (tmp != buf[i]) {
294 			ret = rv3029_write_regs(dev, reg, &buf[i], 1);
295 			if (ret < 0)
296 				break;
297 		}
298 		ret = rv3029_eeprom_busywait(dev);
299 		if (ret < 0)
300 			break;
301 	}
302 
303 	err = rv3029_eeprom_exit(dev);
304 	if (err < 0)
305 		return err;
306 
307 	return ret;
308 }
309 
310 static int rv3029_eeprom_update_bits(struct device *dev,
311 				     u8 reg, u8 mask, u8 set)
312 {
313 	u8 buf;
314 	int ret;
315 
316 	ret = rv3029_eeprom_read(dev, reg, &buf, 1);
317 	if (ret < 0)
318 		return ret;
319 	buf &= ~mask;
320 	buf |= set & mask;
321 	ret = rv3029_eeprom_write(dev, reg, &buf, 1);
322 	if (ret < 0)
323 		return ret;
324 
325 	return 0;
326 }
327 
328 static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
329 {
330 	struct device *dev = dev_id;
331 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
332 	struct mutex *lock = &rv3029->rtc->ops_lock;
333 	unsigned long events = 0;
334 	u8 flags, controls;
335 	int ret;
336 
337 	mutex_lock(lock);
338 
339 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
340 	if (ret) {
341 		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
342 		mutex_unlock(lock);
343 		return IRQ_NONE;
344 	}
345 
346 	ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
347 	if (ret) {
348 		dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
349 		mutex_unlock(lock);
350 		return IRQ_NONE;
351 	}
352 
353 	if (flags & RV3029_IRQ_FLAGS_AF) {
354 		flags &= ~RV3029_IRQ_FLAGS_AF;
355 		controls &= ~RV3029_IRQ_CTRL_AIE;
356 		events |= RTC_AF;
357 	}
358 
359 	if (events) {
360 		rtc_update_irq(rv3029->rtc, 1, events);
361 		rv3029_write_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
362 		rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
363 	}
364 	mutex_unlock(lock);
365 
366 	return IRQ_HANDLED;
367 }
368 
369 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
370 {
371 	u8 buf[1];
372 	int ret;
373 	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
374 
375 	ret = rv3029_get_sr(dev, buf);
376 	if (ret < 0) {
377 		dev_err(dev, "%s: reading SR failed\n", __func__);
378 		return -EIO;
379 	}
380 
381 	ret = rv3029_read_regs(dev, RV3029_W_SEC, regs,
382 			       RV3029_WATCH_SECTION_LEN);
383 	if (ret < 0) {
384 		dev_err(dev, "%s: reading RTC section failed\n", __func__);
385 		return ret;
386 	}
387 
388 	tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
389 	tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
390 
391 	/* HR field has a more complex interpretation */
392 	{
393 		const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
394 
395 		if (_hr & RV3029_REG_HR_12_24) {
396 			/* 12h format */
397 			tm->tm_hour = bcd2bin(_hr & 0x1f);
398 			if (_hr & RV3029_REG_HR_PM)	/* PM flag set */
399 				tm->tm_hour += 12;
400 		} else /* 24h format */
401 			tm->tm_hour = bcd2bin(_hr & 0x3f);
402 	}
403 
404 	tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
405 	tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
406 	tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
407 	tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
408 
409 	return 0;
410 }
411 
412 static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
413 {
414 	struct rtc_time *const tm = &alarm->time;
415 	int ret;
416 	u8 regs[8], controls, flags;
417 
418 	ret = rv3029_get_sr(dev, regs);
419 	if (ret < 0) {
420 		dev_err(dev, "%s: reading SR failed\n", __func__);
421 		return -EIO;
422 	}
423 
424 	ret = rv3029_read_regs(dev, RV3029_A_SC, regs,
425 			       RV3029_ALARM_SECTION_LEN);
426 
427 	if (ret < 0) {
428 		dev_err(dev, "%s: reading alarm section failed\n", __func__);
429 		return ret;
430 	}
431 
432 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
433 	if (ret) {
434 		dev_err(dev, "Read IRQ Control Register error %d\n", ret);
435 		return ret;
436 	}
437 	ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
438 	if (ret < 0) {
439 		dev_err(dev, "Read IRQ Flags Register error %d\n", ret);
440 		return ret;
441 	}
442 
443 	tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
444 	tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
445 	tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
446 	tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
447 	tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
448 	tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
449 	tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
450 
451 	alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
452 	alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
453 
454 	return 0;
455 }
456 
457 static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
458 {
459 	int ret;
460 	u8 controls;
461 
462 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
463 	if (ret < 0) {
464 		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
465 		return ret;
466 	}
467 
468 	/* enable/disable AIE irq */
469 	if (enable)
470 		controls |= RV3029_IRQ_CTRL_AIE;
471 	else
472 		controls &= ~RV3029_IRQ_CTRL_AIE;
473 
474 	ret = rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
475 	if (ret < 0) {
476 		dev_err(dev, "can't update INT reg\n");
477 		return ret;
478 	}
479 
480 	return 0;
481 }
482 
483 static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
484 {
485 	struct rtc_time *const tm = &alarm->time;
486 	int ret;
487 	u8 regs[8];
488 
489 	/*
490 	 * The clock has an 8 bit wide bcd-coded register (they never learn)
491 	 * for the year. tm_year is an offset from 1900 and we are interested
492 	 * in the 2000-2099 range, so any value less than 100 is invalid.
493 	*/
494 	if (tm->tm_year < 100)
495 		return -EINVAL;
496 
497 	ret = rv3029_get_sr(dev, regs);
498 	if (ret < 0) {
499 		dev_err(dev, "%s: reading SR failed\n", __func__);
500 		return -EIO;
501 	}
502 
503 	/* Activate all the alarms with AE_x bit */
504 	regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
505 	regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
506 	regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
507 		| RV3029_A_AE_X;
508 	regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
509 		| RV3029_A_AE_X;
510 	regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
511 		| RV3029_A_AE_X;
512 	regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
513 		| RV3029_A_AE_X;
514 	regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
515 		| RV3029_A_AE_X;
516 
517 	/* Write the alarm */
518 	ret = rv3029_write_regs(dev, RV3029_A_SC, regs,
519 				RV3029_ALARM_SECTION_LEN);
520 	if (ret < 0)
521 		return ret;
522 
523 	if (alarm->enabled) {
524 		/* enable AIE irq */
525 		ret = rv3029_alarm_irq_enable(dev, 1);
526 		if (ret)
527 			return ret;
528 	} else {
529 		/* disable AIE irq */
530 		ret = rv3029_alarm_irq_enable(dev, 0);
531 		if (ret)
532 			return ret;
533 	}
534 
535 	return 0;
536 }
537 
538 static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
539 {
540 	u8 regs[8];
541 	int ret;
542 
543 	/*
544 	 * The clock has an 8 bit wide bcd-coded register (they never learn)
545 	 * for the year. tm_year is an offset from 1900 and we are interested
546 	 * in the 2000-2099 range, so any value less than 100 is invalid.
547 	*/
548 	if (tm->tm_year < 100)
549 		return -EINVAL;
550 
551 	regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
552 	regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
553 	regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
554 	regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
555 	regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
556 	regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
557 	regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
558 
559 	ret = rv3029_write_regs(dev, RV3029_W_SEC, regs,
560 				RV3029_WATCH_SECTION_LEN);
561 	if (ret < 0)
562 		return ret;
563 
564 	ret = rv3029_get_sr(dev, regs);
565 	if (ret < 0) {
566 		dev_err(dev, "%s: reading SR failed\n", __func__);
567 		return ret;
568 	}
569 	/* clear PON bit */
570 	ret = rv3029_set_sr(dev, (regs[0] & ~RV3029_STATUS_PON));
571 	if (ret < 0) {
572 		dev_err(dev, "%s: reading SR failed\n", __func__);
573 		return ret;
574 	}
575 
576 	return 0;
577 }
578 
579 static const struct rv3029_trickle_tab_elem {
580 	u32 r;		/* resistance in ohms */
581 	u8 conf;	/* trickle config bits */
582 } rv3029_trickle_tab[] = {
583 	{
584 		.r	= 1076,
585 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
586 			  RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
587 	}, {
588 		.r	= 1091,
589 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
590 			  RV3029_TRICKLE_20K,
591 	}, {
592 		.r	= 1137,
593 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
594 			  RV3029_TRICKLE_80K,
595 	}, {
596 		.r	= 1154,
597 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
598 	}, {
599 		.r	= 1371,
600 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
601 			  RV3029_TRICKLE_80K,
602 	}, {
603 		.r	= 1395,
604 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
605 	}, {
606 		.r	= 1472,
607 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
608 	}, {
609 		.r	= 1500,
610 		.conf	= RV3029_TRICKLE_1K,
611 	}, {
612 		.r	= 3810,
613 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
614 			  RV3029_TRICKLE_80K,
615 	}, {
616 		.r	= 4000,
617 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
618 	}, {
619 		.r	= 4706,
620 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
621 	}, {
622 		.r	= 5000,
623 		.conf	= RV3029_TRICKLE_5K,
624 	}, {
625 		.r	= 16000,
626 		.conf	= RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
627 	}, {
628 		.r	= 20000,
629 		.conf	= RV3029_TRICKLE_20K,
630 	}, {
631 		.r	= 80000,
632 		.conf	= RV3029_TRICKLE_80K,
633 	},
634 };
635 
636 static void rv3029_trickle_config(struct device *dev)
637 {
638 	struct device_node *of_node = dev->of_node;
639 	const struct rv3029_trickle_tab_elem *elem;
640 	int i, err;
641 	u32 ohms;
642 	u8 trickle_set_bits;
643 
644 	if (!of_node)
645 		return;
646 
647 	/* Configure the trickle charger. */
648 	err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
649 	if (err) {
650 		/* Disable trickle charger. */
651 		trickle_set_bits = 0;
652 	} else {
653 		/* Enable trickle charger. */
654 		for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
655 			elem = &rv3029_trickle_tab[i];
656 			if (elem->r >= ohms)
657 				break;
658 		}
659 		trickle_set_bits = elem->conf;
660 		dev_info(dev,
661 			 "Trickle charger enabled at %d ohms resistance.\n",
662 			 elem->r);
663 	}
664 	err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
665 					RV3029_TRICKLE_MASK,
666 					trickle_set_bits);
667 	if (err < 0)
668 		dev_err(dev, "Failed to update trickle charger config\n");
669 }
670 
671 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
672 
673 static int rv3029_read_temp(struct device *dev, int *temp_mC)
674 {
675 	int ret;
676 	u8 temp;
677 
678 	ret = rv3029_read_regs(dev, RV3029_TEMP_PAGE, &temp, 1);
679 	if (ret < 0)
680 		return ret;
681 
682 	*temp_mC = ((int)temp - 60) * 1000;
683 
684 	return 0;
685 }
686 
687 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
688 				      struct device_attribute *attr,
689 				      char *buf)
690 {
691 	int ret, temp_mC;
692 
693 	ret = rv3029_read_temp(dev, &temp_mC);
694 	if (ret < 0)
695 		return ret;
696 
697 	return sprintf(buf, "%d\n", temp_mC);
698 }
699 
700 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
701 						struct device_attribute *attr,
702 						const char *buf,
703 						size_t count)
704 {
705 	unsigned long interval_ms;
706 	int ret;
707 	u8 th_set_bits = 0;
708 
709 	ret = kstrtoul(buf, 10, &interval_ms);
710 	if (ret < 0)
711 		return ret;
712 
713 	if (interval_ms != 0) {
714 		th_set_bits |= RV3029_EECTRL_THE;
715 		if (interval_ms >= 16000)
716 			th_set_bits |= RV3029_EECTRL_THP;
717 	}
718 	ret = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
719 					RV3029_EECTRL_THE | RV3029_EECTRL_THP,
720 					th_set_bits);
721 	if (ret < 0)
722 		return ret;
723 
724 	return count;
725 }
726 
727 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
728 						 struct device_attribute *attr,
729 						 char *buf)
730 {
731 	int ret, interval_ms;
732 	u8 eectrl;
733 
734 	ret = rv3029_eeprom_read(dev, RV3029_CONTROL_E2P_EECTRL,
735 				 &eectrl, 1);
736 	if (ret < 0)
737 		return ret;
738 
739 	if (eectrl & RV3029_EECTRL_THE) {
740 		if (eectrl & RV3029_EECTRL_THP)
741 			interval_ms = 16000;
742 		else
743 			interval_ms = 1000;
744 	} else {
745 		interval_ms = 0;
746 	}
747 
748 	return sprintf(buf, "%d\n", interval_ms);
749 }
750 
751 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
752 			  NULL, 0);
753 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
754 			  rv3029_hwmon_show_update_interval,
755 			  rv3029_hwmon_set_update_interval, 0);
756 
757 static struct attribute *rv3029_hwmon_attrs[] = {
758 	&sensor_dev_attr_temp1_input.dev_attr.attr,
759 	&sensor_dev_attr_update_interval.dev_attr.attr,
760 	NULL,
761 };
762 ATTRIBUTE_GROUPS(rv3029_hwmon);
763 
764 static void rv3029_hwmon_register(struct device *dev, const char *name)
765 {
766 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
767 	struct device *hwmon_dev;
768 
769 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
770 							   rv3029_hwmon_groups);
771 	if (IS_ERR(hwmon_dev)) {
772 		dev_warn(dev, "unable to register hwmon device %ld\n",
773 			 PTR_ERR(hwmon_dev));
774 	}
775 }
776 
777 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
778 
779 static void rv3029_hwmon_register(struct device *dev, const char *name)
780 {
781 }
782 
783 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
784 
785 static struct rtc_class_ops rv3029_rtc_ops = {
786 	.read_time	= rv3029_read_time,
787 	.set_time	= rv3029_set_time,
788 };
789 
790 static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
791 			const char *name)
792 {
793 	struct rv3029_data *rv3029;
794 	int rc = 0;
795 	u8 buf[1];
796 
797 	rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
798 	if (!rv3029)
799 		return -ENOMEM;
800 
801 	rv3029->regmap = regmap;
802 	rv3029->irq = irq;
803 	rv3029->dev = dev;
804 	dev_set_drvdata(dev, rv3029);
805 
806 	rc = rv3029_get_sr(dev, buf);
807 	if (rc < 0) {
808 		dev_err(dev, "reading status failed\n");
809 		return rc;
810 	}
811 
812 	rv3029_trickle_config(dev);
813 	rv3029_hwmon_register(dev, name);
814 
815 	rv3029->rtc = devm_rtc_device_register(dev, name, &rv3029_rtc_ops,
816 					       THIS_MODULE);
817 	if (IS_ERR(rv3029->rtc)) {
818 		dev_err(dev, "unable to register the class device\n");
819 		return PTR_ERR(rv3029->rtc);
820 	}
821 
822 	if (rv3029->irq > 0) {
823 		rc = devm_request_threaded_irq(dev, rv3029->irq,
824 					       NULL, rv3029_handle_irq,
825 					       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
826 					       "rv3029", dev);
827 		if (rc) {
828 			dev_warn(dev, "unable to request IRQ, alarms disabled\n");
829 			rv3029->irq = 0;
830 		} else {
831 			rv3029_rtc_ops.read_alarm = rv3029_read_alarm;
832 			rv3029_rtc_ops.set_alarm = rv3029_set_alarm;
833 			rv3029_rtc_ops.alarm_irq_enable = rv3029_alarm_irq_enable;
834 		}
835 	}
836 
837 	return 0;
838 }
839 
840 #if IS_ENABLED(CONFIG_I2C)
841 
842 static int rv3029_i2c_probe(struct i2c_client *client,
843 			    const struct i2c_device_id *id)
844 {
845 	struct regmap *regmap;
846 	static const struct regmap_config config = {
847 		.reg_bits = 8,
848 		.val_bits = 8,
849 	};
850 
851 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
852 				     I2C_FUNC_SMBUS_BYTE)) {
853 		dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
854 		return -ENODEV;
855 	}
856 
857 	regmap = devm_regmap_init_i2c(client, &config);
858 	if (IS_ERR(regmap)) {
859 		dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
860 			__func__, PTR_ERR(regmap));
861 		return PTR_ERR(regmap);
862 	}
863 
864 	return rv3029_probe(&client->dev, regmap, client->irq, client->name);
865 }
866 
867 static const struct i2c_device_id rv3029_id[] = {
868 	{ "rv3029", 0 },
869 	{ "rv3029c2", 0 },
870 	{ }
871 };
872 MODULE_DEVICE_TABLE(i2c, rv3029_id);
873 
874 static const struct of_device_id rv3029_of_match[] = {
875 	{ .compatible = "microcrystal,rv3029" },
876 	/* Backward compatibility only, do not use compatibles below: */
877 	{ .compatible = "rv3029" },
878 	{ .compatible = "rv3029c2" },
879 	{ .compatible = "mc,rv3029c2" },
880 	{ }
881 };
882 MODULE_DEVICE_TABLE(of, rv3029_of_match);
883 
884 static struct i2c_driver rv3029_driver = {
885 	.driver = {
886 		.name = "rtc-rv3029c2",
887 		.of_match_table = of_match_ptr(rv3029_of_match),
888 	},
889 	.probe		= rv3029_i2c_probe,
890 	.id_table	= rv3029_id,
891 };
892 
893 static int rv3029_register_driver(void)
894 {
895 	return i2c_add_driver(&rv3029_driver);
896 }
897 
898 static void rv3029_unregister_driver(void)
899 {
900 	i2c_del_driver(&rv3029_driver);
901 }
902 
903 #else
904 
905 static int rv3029_register_driver(void)
906 {
907 	return 0;
908 }
909 
910 static void rv3029_unregister_driver(void)
911 {
912 }
913 
914 #endif
915 
916 #if IS_ENABLED(CONFIG_SPI_MASTER)
917 
918 static int rv3049_probe(struct spi_device *spi)
919 {
920 	static const struct regmap_config config = {
921 		.reg_bits = 8,
922 		.val_bits = 8,
923 	};
924 	struct regmap *regmap;
925 
926 	regmap = devm_regmap_init_spi(spi, &config);
927 	if (IS_ERR(regmap)) {
928 		dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
929 			__func__, PTR_ERR(regmap));
930 		return PTR_ERR(regmap);
931 	}
932 
933 	return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
934 }
935 
936 static struct spi_driver rv3049_driver = {
937 	.driver = {
938 		.name    = "rv3049",
939 	},
940 	.probe   = rv3049_probe,
941 };
942 
943 static int rv3049_register_driver(void)
944 {
945 	return spi_register_driver(&rv3049_driver);
946 }
947 
948 static void rv3049_unregister_driver(void)
949 {
950 	spi_unregister_driver(&rv3049_driver);
951 }
952 
953 #else
954 
955 static int rv3049_register_driver(void)
956 {
957 	return 0;
958 }
959 
960 static void rv3049_unregister_driver(void)
961 {
962 }
963 
964 #endif
965 
966 static int __init rv30x9_init(void)
967 {
968 	int ret;
969 
970 	ret = rv3029_register_driver();
971 	if (ret) {
972 		pr_err("Failed to register rv3029 driver: %d\n", ret);
973 		return ret;
974 	}
975 
976 	ret = rv3049_register_driver();
977 	if (ret) {
978 		pr_err("Failed to register rv3049 driver: %d\n", ret);
979 		rv3029_unregister_driver();
980 	}
981 
982 	return ret;
983 }
984 module_init(rv30x9_init)
985 
986 static void __exit rv30x9_exit(void)
987 {
988 	rv3049_unregister_driver();
989 	rv3029_unregister_driver();
990 }
991 module_exit(rv30x9_exit)
992 
993 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
994 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
995 MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
996 MODULE_LICENSE("GPL");
997 MODULE_ALIAS("spi:rv3049");
998