xref: /linux/drivers/rtc/rtc-rv3029c2.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 /*
2  * Micro Crystal RV-3029 / RV-3049 rtc class driver
3  *
4  * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
5  *         Michael Buesch <m@bues.ch>
6  *
7  * based on previously existing rtc class drivers
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  */
14 
15 #include <linux/module.h>
16 #include <linux/i2c.h>
17 #include <linux/spi/spi.h>
18 #include <linux/bcd.h>
19 #include <linux/rtc.h>
20 #include <linux/delay.h>
21 #include <linux/of.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/regmap.h>
25 
26 /* Register map */
27 /* control section */
28 #define RV3029_ONOFF_CTRL		0x00
29 #define RV3029_ONOFF_CTRL_WE		BIT(0)
30 #define RV3029_ONOFF_CTRL_TE		BIT(1)
31 #define RV3029_ONOFF_CTRL_TAR		BIT(2)
32 #define RV3029_ONOFF_CTRL_EERE		BIT(3)
33 #define RV3029_ONOFF_CTRL_SRON		BIT(4)
34 #define RV3029_ONOFF_CTRL_TD0		BIT(5)
35 #define RV3029_ONOFF_CTRL_TD1		BIT(6)
36 #define RV3029_ONOFF_CTRL_CLKINT	BIT(7)
37 #define RV3029_IRQ_CTRL			0x01
38 #define RV3029_IRQ_CTRL_AIE		BIT(0)
39 #define RV3029_IRQ_CTRL_TIE		BIT(1)
40 #define RV3029_IRQ_CTRL_V1IE		BIT(2)
41 #define RV3029_IRQ_CTRL_V2IE		BIT(3)
42 #define RV3029_IRQ_CTRL_SRIE		BIT(4)
43 #define RV3029_IRQ_FLAGS		0x02
44 #define RV3029_IRQ_FLAGS_AF		BIT(0)
45 #define RV3029_IRQ_FLAGS_TF		BIT(1)
46 #define RV3029_IRQ_FLAGS_V1IF		BIT(2)
47 #define RV3029_IRQ_FLAGS_V2IF		BIT(3)
48 #define RV3029_IRQ_FLAGS_SRF		BIT(4)
49 #define RV3029_STATUS			0x03
50 #define RV3029_STATUS_VLOW1		BIT(2)
51 #define RV3029_STATUS_VLOW2		BIT(3)
52 #define RV3029_STATUS_SR		BIT(4)
53 #define RV3029_STATUS_PON		BIT(5)
54 #define RV3029_STATUS_EEBUSY		BIT(7)
55 #define RV3029_RST_CTRL			0x04
56 #define RV3029_RST_CTRL_SYSR		BIT(4)
57 #define RV3029_CONTROL_SECTION_LEN	0x05
58 
59 /* watch section */
60 #define RV3029_W_SEC			0x08
61 #define RV3029_W_MINUTES		0x09
62 #define RV3029_W_HOURS			0x0A
63 #define RV3029_REG_HR_12_24		BIT(6) /* 24h/12h mode */
64 #define RV3029_REG_HR_PM		BIT(5) /* PM/AM bit in 12h mode */
65 #define RV3029_W_DATE			0x0B
66 #define RV3029_W_DAYS			0x0C
67 #define RV3029_W_MONTHS			0x0D
68 #define RV3029_W_YEARS			0x0E
69 #define RV3029_WATCH_SECTION_LEN	0x07
70 
71 /* alarm section */
72 #define RV3029_A_SC			0x10
73 #define RV3029_A_MN			0x11
74 #define RV3029_A_HR			0x12
75 #define RV3029_A_DT			0x13
76 #define RV3029_A_DW			0x14
77 #define RV3029_A_MO			0x15
78 #define RV3029_A_YR			0x16
79 #define RV3029_A_AE_X			BIT(7)
80 #define RV3029_ALARM_SECTION_LEN	0x07
81 
82 /* timer section */
83 #define RV3029_TIMER_LOW		0x18
84 #define RV3029_TIMER_HIGH		0x19
85 
86 /* temperature section */
87 #define RV3029_TEMP_PAGE		0x20
88 
89 /* eeprom data section */
90 #define RV3029_E2P_EEDATA1		0x28
91 #define RV3029_E2P_EEDATA2		0x29
92 #define RV3029_E2PDATA_SECTION_LEN	0x02
93 
94 /* eeprom control section */
95 #define RV3029_CONTROL_E2P_EECTRL	0x30
96 #define RV3029_EECTRL_THP		BIT(0) /* temp scan interval */
97 #define RV3029_EECTRL_THE		BIT(1) /* thermometer enable */
98 #define RV3029_EECTRL_FD0		BIT(2) /* CLKOUT */
99 #define RV3029_EECTRL_FD1		BIT(3) /* CLKOUT */
100 #define RV3029_TRICKLE_1K		BIT(4) /* 1.5K resistance */
101 #define RV3029_TRICKLE_5K		BIT(5) /* 5K   resistance */
102 #define RV3029_TRICKLE_20K		BIT(6) /* 20K  resistance */
103 #define RV3029_TRICKLE_80K		BIT(7) /* 80K  resistance */
104 #define RV3029_TRICKLE_MASK		(RV3029_TRICKLE_1K |\
105 					 RV3029_TRICKLE_5K |\
106 					 RV3029_TRICKLE_20K |\
107 					 RV3029_TRICKLE_80K)
108 #define RV3029_TRICKLE_SHIFT		4
109 #define RV3029_CONTROL_E2P_XOFFS	0x31 /* XTAL offset */
110 #define RV3029_CONTROL_E2P_XOFFS_SIGN	BIT(7) /* Sign: 1->pos, 0->neg */
111 #define RV3029_CONTROL_E2P_QCOEF	0x32 /* XTAL temp drift coef */
112 #define RV3029_CONTROL_E2P_TURNOVER	0x33 /* XTAL turnover temp (in *C) */
113 #define RV3029_CONTROL_E2P_TOV_MASK	0x3F /* XTAL turnover temp mask */
114 
115 /* user ram section */
116 #define RV3029_USR1_RAM_PAGE		0x38
117 #define RV3029_USR1_SECTION_LEN		0x04
118 #define RV3029_USR2_RAM_PAGE		0x3C
119 #define RV3029_USR2_SECTION_LEN		0x04
120 
121 struct rv3029_data {
122 	struct device		*dev;
123 	struct rtc_device	*rtc;
124 	struct regmap		*regmap;
125 	int irq;
126 };
127 
128 static int rv3029_read_regs(struct device *dev, u8 reg, u8 *buf,
129 			    unsigned int len)
130 {
131 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
132 
133 	if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
134 	    (reg + len > RV3029_USR1_RAM_PAGE + 8))
135 		return -EINVAL;
136 
137 	return regmap_bulk_read(rv3029->regmap, reg, buf, len);
138 }
139 
140 static int rv3029_write_regs(struct device *dev, u8 reg, u8 const buf[],
141 			     unsigned int len)
142 {
143 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
144 
145 	if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
146 	    (reg + len > RV3029_USR1_RAM_PAGE + 8))
147 		return -EINVAL;
148 
149 	return regmap_bulk_write(rv3029->regmap, reg, buf, len);
150 }
151 
152 static int rv3029_update_bits(struct device *dev, u8 reg, u8 mask, u8 set)
153 {
154 	u8 buf;
155 	int ret;
156 
157 	ret = rv3029_read_regs(dev, reg, &buf, 1);
158 	if (ret < 0)
159 		return ret;
160 	buf &= ~mask;
161 	buf |= set & mask;
162 	ret = rv3029_write_regs(dev, reg, &buf, 1);
163 	if (ret < 0)
164 		return ret;
165 
166 	return 0;
167 }
168 
169 static int rv3029_get_sr(struct device *dev, u8 *buf)
170 {
171 	int ret = rv3029_read_regs(dev, RV3029_STATUS, buf, 1);
172 
173 	if (ret < 0)
174 		return -EIO;
175 	dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
176 	return 0;
177 }
178 
179 static int rv3029_set_sr(struct device *dev, u8 val)
180 {
181 	u8 buf[1];
182 	int sr;
183 
184 	buf[0] = val;
185 	sr = rv3029_write_regs(dev, RV3029_STATUS, buf, 1);
186 	dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
187 	if (sr < 0)
188 		return -EIO;
189 	return 0;
190 }
191 
192 static int rv3029_eeprom_busywait(struct device *dev)
193 {
194 	int i, ret;
195 	u8 sr;
196 
197 	for (i = 100; i > 0; i--) {
198 		ret = rv3029_get_sr(dev, &sr);
199 		if (ret < 0)
200 			break;
201 		if (!(sr & RV3029_STATUS_EEBUSY))
202 			break;
203 		usleep_range(1000, 10000);
204 	}
205 	if (i <= 0) {
206 		dev_err(dev, "EEPROM busy wait timeout.\n");
207 		return -ETIMEDOUT;
208 	}
209 
210 	return ret;
211 }
212 
213 static int rv3029_eeprom_exit(struct device *dev)
214 {
215 	/* Re-enable eeprom refresh */
216 	return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
217 				  RV3029_ONOFF_CTRL_EERE,
218 				  RV3029_ONOFF_CTRL_EERE);
219 }
220 
221 static int rv3029_eeprom_enter(struct device *dev)
222 {
223 	int ret;
224 	u8 sr;
225 
226 	/* Check whether we are in the allowed voltage range. */
227 	ret = rv3029_get_sr(dev, &sr);
228 	if (ret < 0)
229 		return ret;
230 	if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
231 		/* We clear the bits and retry once just in case
232 		 * we had a brown out in early startup.
233 		 */
234 		sr &= ~RV3029_STATUS_VLOW1;
235 		sr &= ~RV3029_STATUS_VLOW2;
236 		ret = rv3029_set_sr(dev, sr);
237 		if (ret < 0)
238 			return ret;
239 		usleep_range(1000, 10000);
240 		ret = rv3029_get_sr(dev, &sr);
241 		if (ret < 0)
242 			return ret;
243 		if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
244 			dev_err(dev,
245 				"Supply voltage is too low to safely access the EEPROM.\n");
246 			return -ENODEV;
247 		}
248 	}
249 
250 	/* Disable eeprom refresh. */
251 	ret = rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE,
252 				 0);
253 	if (ret < 0)
254 		return ret;
255 
256 	/* Wait for any previous eeprom accesses to finish. */
257 	ret = rv3029_eeprom_busywait(dev);
258 	if (ret < 0)
259 		rv3029_eeprom_exit(dev);
260 
261 	return ret;
262 }
263 
264 static int rv3029_eeprom_read(struct device *dev, u8 reg,
265 			      u8 buf[], size_t len)
266 {
267 	int ret, err;
268 
269 	err = rv3029_eeprom_enter(dev);
270 	if (err < 0)
271 		return err;
272 
273 	ret = rv3029_read_regs(dev, reg, buf, len);
274 
275 	err = rv3029_eeprom_exit(dev);
276 	if (err < 0)
277 		return err;
278 
279 	return ret;
280 }
281 
282 static int rv3029_eeprom_write(struct device *dev, u8 reg,
283 			       u8 const buf[], size_t len)
284 {
285 	int ret;
286 	size_t i;
287 	u8 tmp;
288 
289 	ret = rv3029_eeprom_enter(dev);
290 	if (ret < 0)
291 		return ret;
292 
293 	for (i = 0; i < len; i++, reg++) {
294 		ret = rv3029_read_regs(dev, reg, &tmp, 1);
295 		if (ret < 0)
296 			break;
297 		if (tmp != buf[i]) {
298 			ret = rv3029_write_regs(dev, reg, &buf[i], 1);
299 			if (ret < 0)
300 				break;
301 		}
302 		ret = rv3029_eeprom_busywait(dev);
303 		if (ret < 0)
304 			break;
305 	}
306 
307 	ret = rv3029_eeprom_exit(dev);
308 	if (ret < 0)
309 		return ret;
310 
311 	return 0;
312 }
313 
314 static int rv3029_eeprom_update_bits(struct device *dev,
315 				     u8 reg, u8 mask, u8 set)
316 {
317 	u8 buf;
318 	int ret;
319 
320 	ret = rv3029_eeprom_read(dev, reg, &buf, 1);
321 	if (ret < 0)
322 		return ret;
323 	buf &= ~mask;
324 	buf |= set & mask;
325 	ret = rv3029_eeprom_write(dev, reg, &buf, 1);
326 	if (ret < 0)
327 		return ret;
328 
329 	return 0;
330 }
331 
332 static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
333 {
334 	struct device *dev = dev_id;
335 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
336 	struct mutex *lock = &rv3029->rtc->ops_lock;
337 	unsigned long events = 0;
338 	u8 flags, controls;
339 	int ret;
340 
341 	mutex_lock(lock);
342 
343 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
344 	if (ret) {
345 		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
346 		mutex_unlock(lock);
347 		return IRQ_NONE;
348 	}
349 
350 	ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
351 	if (ret) {
352 		dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
353 		mutex_unlock(lock);
354 		return IRQ_NONE;
355 	}
356 
357 	if (flags & RV3029_IRQ_FLAGS_AF) {
358 		flags &= ~RV3029_IRQ_FLAGS_AF;
359 		controls &= ~RV3029_IRQ_CTRL_AIE;
360 		events |= RTC_AF;
361 	}
362 
363 	if (events) {
364 		rtc_update_irq(rv3029->rtc, 1, events);
365 		rv3029_write_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
366 		rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
367 	}
368 	mutex_unlock(lock);
369 
370 	return IRQ_HANDLED;
371 }
372 
373 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
374 {
375 	u8 buf[1];
376 	int ret;
377 	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
378 
379 	ret = rv3029_get_sr(dev, buf);
380 	if (ret < 0) {
381 		dev_err(dev, "%s: reading SR failed\n", __func__);
382 		return -EIO;
383 	}
384 
385 	ret = rv3029_read_regs(dev, RV3029_W_SEC, regs,
386 			       RV3029_WATCH_SECTION_LEN);
387 	if (ret < 0) {
388 		dev_err(dev, "%s: reading RTC section failed\n", __func__);
389 		return ret;
390 	}
391 
392 	tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
393 	tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
394 
395 	/* HR field has a more complex interpretation */
396 	{
397 		const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
398 
399 		if (_hr & RV3029_REG_HR_12_24) {
400 			/* 12h format */
401 			tm->tm_hour = bcd2bin(_hr & 0x1f);
402 			if (_hr & RV3029_REG_HR_PM)	/* PM flag set */
403 				tm->tm_hour += 12;
404 		} else /* 24h format */
405 			tm->tm_hour = bcd2bin(_hr & 0x3f);
406 	}
407 
408 	tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
409 	tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
410 	tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
411 	tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
412 
413 	return 0;
414 }
415 
416 static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
417 {
418 	struct rtc_time *const tm = &alarm->time;
419 	int ret;
420 	u8 regs[8], controls, flags;
421 
422 	ret = rv3029_get_sr(dev, regs);
423 	if (ret < 0) {
424 		dev_err(dev, "%s: reading SR failed\n", __func__);
425 		return -EIO;
426 	}
427 
428 	ret = rv3029_read_regs(dev, RV3029_A_SC, regs,
429 			       RV3029_ALARM_SECTION_LEN);
430 
431 	if (ret < 0) {
432 		dev_err(dev, "%s: reading alarm section failed\n", __func__);
433 		return ret;
434 	}
435 
436 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
437 	if (ret) {
438 		dev_err(dev, "Read IRQ Control Register error %d\n", ret);
439 		return ret;
440 	}
441 	ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
442 	if (ret < 0) {
443 		dev_err(dev, "Read IRQ Flags Register error %d\n", ret);
444 		return ret;
445 	}
446 
447 	tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
448 	tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
449 	tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
450 	tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
451 	tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
452 	tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
453 	tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
454 
455 	alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
456 	alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
457 
458 	return 0;
459 }
460 
461 static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
462 {
463 	int ret;
464 	u8 controls;
465 
466 	ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
467 	if (ret < 0) {
468 		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
469 		return ret;
470 	}
471 
472 	/* enable/disable AIE irq */
473 	if (enable)
474 		controls |= RV3029_IRQ_CTRL_AIE;
475 	else
476 		controls &= ~RV3029_IRQ_CTRL_AIE;
477 
478 	ret = rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
479 	if (ret < 0) {
480 		dev_err(dev, "can't update INT reg\n");
481 		return ret;
482 	}
483 
484 	return 0;
485 }
486 
487 static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
488 {
489 	struct rtc_time *const tm = &alarm->time;
490 	int ret;
491 	u8 regs[8];
492 
493 	/*
494 	 * The clock has an 8 bit wide bcd-coded register (they never learn)
495 	 * for the year. tm_year is an offset from 1900 and we are interested
496 	 * in the 2000-2099 range, so any value less than 100 is invalid.
497 	*/
498 	if (tm->tm_year < 100)
499 		return -EINVAL;
500 
501 	ret = rv3029_get_sr(dev, regs);
502 	if (ret < 0) {
503 		dev_err(dev, "%s: reading SR failed\n", __func__);
504 		return -EIO;
505 	}
506 
507 	/* Activate all the alarms with AE_x bit */
508 	regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
509 	regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
510 	regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
511 		| RV3029_A_AE_X;
512 	regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
513 		| RV3029_A_AE_X;
514 	regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
515 		| RV3029_A_AE_X;
516 	regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
517 		| RV3029_A_AE_X;
518 	regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
519 		| RV3029_A_AE_X;
520 
521 	/* Write the alarm */
522 	ret = rv3029_write_regs(dev, RV3029_A_SC, regs,
523 				RV3029_ALARM_SECTION_LEN);
524 	if (ret < 0)
525 		return ret;
526 
527 	if (alarm->enabled) {
528 		/* enable AIE irq */
529 		ret = rv3029_alarm_irq_enable(dev, 1);
530 		if (ret)
531 			return ret;
532 	} else {
533 		/* disable AIE irq */
534 		ret = rv3029_alarm_irq_enable(dev, 0);
535 		if (ret)
536 			return ret;
537 	}
538 
539 	return 0;
540 }
541 
542 static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
543 {
544 	u8 regs[8];
545 	int ret;
546 
547 	/*
548 	 * The clock has an 8 bit wide bcd-coded register (they never learn)
549 	 * for the year. tm_year is an offset from 1900 and we are interested
550 	 * in the 2000-2099 range, so any value less than 100 is invalid.
551 	*/
552 	if (tm->tm_year < 100)
553 		return -EINVAL;
554 
555 	regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
556 	regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
557 	regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
558 	regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
559 	regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
560 	regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
561 	regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
562 
563 	ret = rv3029_write_regs(dev, RV3029_W_SEC, regs,
564 				RV3029_WATCH_SECTION_LEN);
565 	if (ret < 0)
566 		return ret;
567 
568 	ret = rv3029_get_sr(dev, regs);
569 	if (ret < 0) {
570 		dev_err(dev, "%s: reading SR failed\n", __func__);
571 		return ret;
572 	}
573 	/* clear PON bit */
574 	ret = rv3029_set_sr(dev, (regs[0] & ~RV3029_STATUS_PON));
575 	if (ret < 0) {
576 		dev_err(dev, "%s: reading SR failed\n", __func__);
577 		return ret;
578 	}
579 
580 	return 0;
581 }
582 
583 static const struct rv3029_trickle_tab_elem {
584 	u32 r;		/* resistance in ohms */
585 	u8 conf;	/* trickle config bits */
586 } rv3029_trickle_tab[] = {
587 	{
588 		.r	= 1076,
589 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
590 			  RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
591 	}, {
592 		.r	= 1091,
593 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
594 			  RV3029_TRICKLE_20K,
595 	}, {
596 		.r	= 1137,
597 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
598 			  RV3029_TRICKLE_80K,
599 	}, {
600 		.r	= 1154,
601 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
602 	}, {
603 		.r	= 1371,
604 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
605 			  RV3029_TRICKLE_80K,
606 	}, {
607 		.r	= 1395,
608 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
609 	}, {
610 		.r	= 1472,
611 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
612 	}, {
613 		.r	= 1500,
614 		.conf	= RV3029_TRICKLE_1K,
615 	}, {
616 		.r	= 3810,
617 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
618 			  RV3029_TRICKLE_80K,
619 	}, {
620 		.r	= 4000,
621 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
622 	}, {
623 		.r	= 4706,
624 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
625 	}, {
626 		.r	= 5000,
627 		.conf	= RV3029_TRICKLE_5K,
628 	}, {
629 		.r	= 16000,
630 		.conf	= RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
631 	}, {
632 		.r	= 20000,
633 		.conf	= RV3029_TRICKLE_20K,
634 	}, {
635 		.r	= 80000,
636 		.conf	= RV3029_TRICKLE_80K,
637 	},
638 };
639 
640 static void rv3029_trickle_config(struct device *dev)
641 {
642 	struct device_node *of_node = dev->of_node;
643 	const struct rv3029_trickle_tab_elem *elem;
644 	int i, err;
645 	u32 ohms;
646 	u8 trickle_set_bits;
647 
648 	if (!of_node)
649 		return;
650 
651 	/* Configure the trickle charger. */
652 	err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
653 	if (err) {
654 		/* Disable trickle charger. */
655 		trickle_set_bits = 0;
656 	} else {
657 		/* Enable trickle charger. */
658 		for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
659 			elem = &rv3029_trickle_tab[i];
660 			if (elem->r >= ohms)
661 				break;
662 		}
663 		trickle_set_bits = elem->conf;
664 		dev_info(dev,
665 			 "Trickle charger enabled at %d ohms resistance.\n",
666 			 elem->r);
667 	}
668 	err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
669 					RV3029_TRICKLE_MASK,
670 					trickle_set_bits);
671 	if (err < 0)
672 		dev_err(dev, "Failed to update trickle charger config\n");
673 }
674 
675 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
676 
677 static int rv3029_read_temp(struct device *dev, int *temp_mC)
678 {
679 	int ret;
680 	u8 temp;
681 
682 	ret = rv3029_read_regs(dev, RV3029_TEMP_PAGE, &temp, 1);
683 	if (ret < 0)
684 		return ret;
685 
686 	*temp_mC = ((int)temp - 60) * 1000;
687 
688 	return 0;
689 }
690 
691 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
692 				      struct device_attribute *attr,
693 				      char *buf)
694 {
695 	int ret, temp_mC;
696 
697 	ret = rv3029_read_temp(dev, &temp_mC);
698 	if (ret < 0)
699 		return ret;
700 
701 	return sprintf(buf, "%d\n", temp_mC);
702 }
703 
704 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
705 						struct device_attribute *attr,
706 						const char *buf,
707 						size_t count)
708 {
709 	unsigned long interval_ms;
710 	int ret;
711 	u8 th_set_bits = 0;
712 
713 	ret = kstrtoul(buf, 10, &interval_ms);
714 	if (ret < 0)
715 		return ret;
716 
717 	if (interval_ms != 0) {
718 		th_set_bits |= RV3029_EECTRL_THE;
719 		if (interval_ms >= 16000)
720 			th_set_bits |= RV3029_EECTRL_THP;
721 	}
722 	ret = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
723 					RV3029_EECTRL_THE | RV3029_EECTRL_THP,
724 					th_set_bits);
725 	if (ret < 0)
726 		return ret;
727 
728 	return count;
729 }
730 
731 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
732 						 struct device_attribute *attr,
733 						 char *buf)
734 {
735 	int ret, interval_ms;
736 	u8 eectrl;
737 
738 	ret = rv3029_eeprom_read(dev, RV3029_CONTROL_E2P_EECTRL,
739 				 &eectrl, 1);
740 	if (ret < 0)
741 		return ret;
742 
743 	if (eectrl & RV3029_EECTRL_THE) {
744 		if (eectrl & RV3029_EECTRL_THP)
745 			interval_ms = 16000;
746 		else
747 			interval_ms = 1000;
748 	} else {
749 		interval_ms = 0;
750 	}
751 
752 	return sprintf(buf, "%d\n", interval_ms);
753 }
754 
755 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
756 			  NULL, 0);
757 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
758 			  rv3029_hwmon_show_update_interval,
759 			  rv3029_hwmon_set_update_interval, 0);
760 
761 static struct attribute *rv3029_hwmon_attrs[] = {
762 	&sensor_dev_attr_temp1_input.dev_attr.attr,
763 	&sensor_dev_attr_update_interval.dev_attr.attr,
764 	NULL,
765 };
766 ATTRIBUTE_GROUPS(rv3029_hwmon);
767 
768 static void rv3029_hwmon_register(struct device *dev, const char *name)
769 {
770 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
771 	struct device *hwmon_dev;
772 
773 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
774 							   rv3029_hwmon_groups);
775 	if (IS_ERR(hwmon_dev)) {
776 		dev_warn(dev, "unable to register hwmon device %ld\n",
777 			 PTR_ERR(hwmon_dev));
778 	}
779 }
780 
781 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
782 
783 static void rv3029_hwmon_register(struct device *dev, const char *name)
784 {
785 }
786 
787 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
788 
789 static struct rtc_class_ops rv3029_rtc_ops = {
790 	.read_time	= rv3029_read_time,
791 	.set_time	= rv3029_set_time,
792 };
793 
794 static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
795 			const char *name)
796 {
797 	struct rv3029_data *rv3029;
798 	int rc = 0;
799 	u8 buf[1];
800 
801 	rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
802 	if (!rv3029)
803 		return -ENOMEM;
804 
805 	rv3029->regmap = regmap;
806 	rv3029->irq = irq;
807 	rv3029->dev = dev;
808 	dev_set_drvdata(dev, rv3029);
809 
810 	rc = rv3029_get_sr(dev, buf);
811 	if (rc < 0) {
812 		dev_err(dev, "reading status failed\n");
813 		return rc;
814 	}
815 
816 	rv3029_trickle_config(dev);
817 	rv3029_hwmon_register(dev, name);
818 
819 	rv3029->rtc = devm_rtc_device_register(dev, name, &rv3029_rtc_ops,
820 					       THIS_MODULE);
821 	if (IS_ERR(rv3029->rtc)) {
822 		dev_err(dev, "unable to register the class device\n");
823 		return PTR_ERR(rv3029->rtc);
824 	}
825 
826 	if (rv3029->irq > 0) {
827 		rc = devm_request_threaded_irq(dev, rv3029->irq,
828 					       NULL, rv3029_handle_irq,
829 					       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
830 					       "rv3029", dev);
831 		if (rc) {
832 			dev_warn(dev, "unable to request IRQ, alarms disabled\n");
833 			rv3029->irq = 0;
834 		} else {
835 			rv3029_rtc_ops.read_alarm = rv3029_read_alarm;
836 			rv3029_rtc_ops.set_alarm = rv3029_set_alarm;
837 			rv3029_rtc_ops.alarm_irq_enable = rv3029_alarm_irq_enable;
838 		}
839 	}
840 
841 	return 0;
842 }
843 
844 #if IS_ENABLED(CONFIG_I2C)
845 
846 static int rv3029_i2c_probe(struct i2c_client *client,
847 			    const struct i2c_device_id *id)
848 {
849 	struct regmap *regmap;
850 	static const struct regmap_config config = {
851 		.reg_bits = 8,
852 		.val_bits = 8,
853 	};
854 
855 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
856 				     I2C_FUNC_SMBUS_BYTE)) {
857 		dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
858 		return -ENODEV;
859 	}
860 
861 	regmap = devm_regmap_init_i2c(client, &config);
862 	if (IS_ERR(regmap)) {
863 		dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
864 			__func__, PTR_ERR(regmap));
865 		return PTR_ERR(regmap);
866 	}
867 
868 	return rv3029_probe(&client->dev, regmap, client->irq, client->name);
869 }
870 
871 static const struct i2c_device_id rv3029_id[] = {
872 	{ "rv3029", 0 },
873 	{ "rv3029c2", 0 },
874 	{ }
875 };
876 MODULE_DEVICE_TABLE(i2c, rv3029_id);
877 
878 static const struct of_device_id rv3029_of_match[] = {
879 	{ .compatible = "microcrystal,rv3029" },
880 	/* Backward compatibility only, do not use compatibles below: */
881 	{ .compatible = "rv3029" },
882 	{ .compatible = "rv3029c2" },
883 	{ .compatible = "mc,rv3029c2" },
884 	{ }
885 };
886 MODULE_DEVICE_TABLE(of, rv3029_of_match);
887 
888 static struct i2c_driver rv3029_driver = {
889 	.driver = {
890 		.name = "rtc-rv3029c2",
891 		.of_match_table = of_match_ptr(rv3029_of_match),
892 	},
893 	.probe		= rv3029_i2c_probe,
894 	.id_table	= rv3029_id,
895 };
896 
897 static int rv3029_register_driver(void)
898 {
899 	return i2c_add_driver(&rv3029_driver);
900 }
901 
902 static void rv3029_unregister_driver(void)
903 {
904 	i2c_del_driver(&rv3029_driver);
905 }
906 
907 #else
908 
909 static int rv3029_register_driver(void)
910 {
911 	return 0;
912 }
913 
914 static void rv3029_unregister_driver(void)
915 {
916 }
917 
918 #endif
919 
920 #if IS_ENABLED(CONFIG_SPI_MASTER)
921 
922 static int rv3049_probe(struct spi_device *spi)
923 {
924 	static const struct regmap_config config = {
925 		.reg_bits = 8,
926 		.val_bits = 8,
927 	};
928 	struct regmap *regmap;
929 
930 	regmap = devm_regmap_init_spi(spi, &config);
931 	if (IS_ERR(regmap)) {
932 		dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
933 			__func__, PTR_ERR(regmap));
934 		return PTR_ERR(regmap);
935 	}
936 
937 	return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
938 }
939 
940 static struct spi_driver rv3049_driver = {
941 	.driver = {
942 		.name    = "rv3049",
943 	},
944 	.probe   = rv3049_probe,
945 };
946 
947 static int rv3049_register_driver(void)
948 {
949 	return spi_register_driver(&rv3049_driver);
950 }
951 
952 static void rv3049_unregister_driver(void)
953 {
954 	spi_unregister_driver(&rv3049_driver);
955 }
956 
957 #else
958 
959 static int rv3049_register_driver(void)
960 {
961 	return 0;
962 }
963 
964 static void rv3049_unregister_driver(void)
965 {
966 }
967 
968 #endif
969 
970 static int __init rv30x9_init(void)
971 {
972 	int ret;
973 
974 	ret = rv3029_register_driver();
975 	if (ret) {
976 		pr_err("Failed to register rv3029 driver: %d\n", ret);
977 		return ret;
978 	}
979 
980 	ret = rv3049_register_driver();
981 	if (ret) {
982 		pr_err("Failed to register rv3049 driver: %d\n", ret);
983 		rv3029_unregister_driver();
984 	}
985 
986 	return ret;
987 }
988 module_init(rv30x9_init)
989 
990 static void __exit rv30x9_exit(void)
991 {
992 	rv3049_unregister_driver();
993 	rv3029_unregister_driver();
994 }
995 module_exit(rv30x9_exit)
996 
997 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
998 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
999 MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
1000 MODULE_LICENSE("GPL");
1001 MODULE_ALIAS("spi:rv3049");
1002