xref: /openbmc/linux/drivers/rtc/rtc-rv3029c2.c (revision 132db935)
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_RAM_PAGE			0x38
113 #define RV3029_RAM_SECTION_LEN		8
114 
115 struct rv3029_data {
116 	struct device		*dev;
117 	struct rtc_device	*rtc;
118 	struct regmap		*regmap;
119 	int irq;
120 };
121 
122 static int rv3029_eeprom_busywait(struct rv3029_data *rv3029)
123 {
124 	unsigned int sr;
125 	int i, ret;
126 
127 	for (i = 100; i > 0; i--) {
128 		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
129 		if (ret < 0)
130 			break;
131 		if (!(sr & RV3029_STATUS_EEBUSY))
132 			break;
133 		usleep_range(1000, 10000);
134 	}
135 	if (i <= 0) {
136 		dev_err(rv3029->dev, "EEPROM busy wait timeout.\n");
137 		return -ETIMEDOUT;
138 	}
139 
140 	return ret;
141 }
142 
143 static int rv3029_eeprom_exit(struct rv3029_data *rv3029)
144 {
145 	/* Re-enable eeprom refresh */
146 	return regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
147 				  RV3029_ONOFF_CTRL_EERE,
148 				  RV3029_ONOFF_CTRL_EERE);
149 }
150 
151 static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
152 {
153 	unsigned int sr;
154 	int ret;
155 
156 	/* Check whether we are in the allowed voltage range. */
157 	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
158 	if (ret < 0)
159 		return ret;
160 	if (sr & RV3029_STATUS_VLOW2)
161 		return -ENODEV;
162 	if (sr & RV3029_STATUS_VLOW1) {
163 		/* We clear the bits and retry once just in case
164 		 * we had a brown out in early startup.
165 		 */
166 		ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
167 					 RV3029_STATUS_VLOW1, 0);
168 		if (ret < 0)
169 			return ret;
170 		usleep_range(1000, 10000);
171 		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
172 		if (ret < 0)
173 			return ret;
174 		if (sr & RV3029_STATUS_VLOW1) {
175 			dev_err(rv3029->dev,
176 				"Supply voltage is too low to safely access the EEPROM.\n");
177 			return -ENODEV;
178 		}
179 	}
180 
181 	/* Disable eeprom refresh. */
182 	ret = regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
183 				 RV3029_ONOFF_CTRL_EERE, 0);
184 	if (ret < 0)
185 		return ret;
186 
187 	/* Wait for any previous eeprom accesses to finish. */
188 	ret = rv3029_eeprom_busywait(rv3029);
189 	if (ret < 0)
190 		rv3029_eeprom_exit(rv3029);
191 
192 	return ret;
193 }
194 
195 static int rv3029_eeprom_read(struct rv3029_data *rv3029, u8 reg,
196 			      u8 buf[], size_t len)
197 {
198 	int ret, err;
199 
200 	err = rv3029_eeprom_enter(rv3029);
201 	if (err < 0)
202 		return err;
203 
204 	ret = regmap_bulk_read(rv3029->regmap, reg, buf, len);
205 
206 	err = rv3029_eeprom_exit(rv3029);
207 	if (err < 0)
208 		return err;
209 
210 	return ret;
211 }
212 
213 static int rv3029_eeprom_write(struct rv3029_data *rv3029, u8 reg,
214 			       u8 const buf[], size_t len)
215 {
216 	unsigned int tmp;
217 	int ret, err;
218 	size_t i;
219 
220 	err = rv3029_eeprom_enter(rv3029);
221 	if (err < 0)
222 		return err;
223 
224 	for (i = 0; i < len; i++, reg++) {
225 		ret = regmap_read(rv3029->regmap, reg, &tmp);
226 		if (ret < 0)
227 			break;
228 		if (tmp != buf[i]) {
229 			tmp = buf[i];
230 			ret = regmap_write(rv3029->regmap, reg, tmp);
231 			if (ret < 0)
232 				break;
233 		}
234 		ret = rv3029_eeprom_busywait(rv3029);
235 		if (ret < 0)
236 			break;
237 	}
238 
239 	err = rv3029_eeprom_exit(rv3029);
240 	if (err < 0)
241 		return err;
242 
243 	return ret;
244 }
245 
246 static int rv3029_eeprom_update_bits(struct rv3029_data *rv3029,
247 				     u8 reg, u8 mask, u8 set)
248 {
249 	u8 buf;
250 	int ret;
251 
252 	ret = rv3029_eeprom_read(rv3029, reg, &buf, 1);
253 	if (ret < 0)
254 		return ret;
255 	buf &= ~mask;
256 	buf |= set & mask;
257 	ret = rv3029_eeprom_write(rv3029, reg, &buf, 1);
258 	if (ret < 0)
259 		return ret;
260 
261 	return 0;
262 }
263 
264 static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
265 {
266 	struct device *dev = dev_id;
267 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
268 	struct mutex *lock = &rv3029->rtc->ops_lock;
269 	unsigned int flags, controls;
270 	unsigned long events = 0;
271 	int ret;
272 
273 	mutex_lock(lock);
274 
275 	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
276 	if (ret) {
277 		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
278 		mutex_unlock(lock);
279 		return IRQ_NONE;
280 	}
281 
282 	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
283 	if (ret) {
284 		dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
285 		mutex_unlock(lock);
286 		return IRQ_NONE;
287 	}
288 
289 	if (flags & RV3029_IRQ_FLAGS_AF) {
290 		flags &= ~RV3029_IRQ_FLAGS_AF;
291 		controls &= ~RV3029_IRQ_CTRL_AIE;
292 		events |= RTC_AF;
293 	}
294 
295 	if (events) {
296 		rtc_update_irq(rv3029->rtc, 1, events);
297 		regmap_write(rv3029->regmap, RV3029_IRQ_FLAGS, flags);
298 		regmap_write(rv3029->regmap, RV3029_IRQ_CTRL, controls);
299 	}
300 	mutex_unlock(lock);
301 
302 	return IRQ_HANDLED;
303 }
304 
305 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
306 {
307 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
308 	unsigned int sr;
309 	int ret;
310 	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
311 
312 	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
313 	if (ret < 0)
314 		return ret;
315 
316 	if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
317 		return -EINVAL;
318 
319 	ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
320 			       RV3029_WATCH_SECTION_LEN);
321 	if (ret < 0)
322 		return ret;
323 
324 	tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
325 	tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
326 
327 	/* HR field has a more complex interpretation */
328 	{
329 		const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
330 
331 		if (_hr & RV3029_REG_HR_12_24) {
332 			/* 12h format */
333 			tm->tm_hour = bcd2bin(_hr & 0x1f);
334 			if (_hr & RV3029_REG_HR_PM)	/* PM flag set */
335 				tm->tm_hour += 12;
336 		} else /* 24h format */
337 			tm->tm_hour = bcd2bin(_hr & 0x3f);
338 	}
339 
340 	tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
341 	tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
342 	tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
343 	tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
344 
345 	return 0;
346 }
347 
348 static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
349 {
350 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
351 	struct rtc_time *const tm = &alarm->time;
352 	unsigned int controls, flags;
353 	int ret;
354 	u8 regs[8];
355 
356 	ret = regmap_bulk_read(rv3029->regmap, RV3029_A_SC, regs,
357 			       RV3029_ALARM_SECTION_LEN);
358 	if (ret < 0)
359 		return ret;
360 
361 	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
362 	if (ret)
363 		return ret;
364 
365 	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
366 	if (ret < 0)
367 		return ret;
368 
369 	tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
370 	tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
371 	tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
372 	tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
373 	tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
374 	tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
375 	tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
376 
377 	alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
378 	alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
379 
380 	return 0;
381 }
382 
383 static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
384 {
385 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
386 
387 	return regmap_update_bits(rv3029->regmap, RV3029_IRQ_CTRL,
388 				  RV3029_IRQ_CTRL_AIE,
389 				  enable ? RV3029_IRQ_CTRL_AIE : 0);
390 }
391 
392 static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
393 {
394 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
395 	struct rtc_time *const tm = &alarm->time;
396 	int ret;
397 	u8 regs[8];
398 
399 	/* Activate all the alarms with AE_x bit */
400 	regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
401 	regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
402 	regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
403 		| RV3029_A_AE_X;
404 	regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
405 		| RV3029_A_AE_X;
406 	regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
407 		| RV3029_A_AE_X;
408 	regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
409 		| RV3029_A_AE_X;
410 	regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
411 		| RV3029_A_AE_X;
412 
413 	/* Write the alarm */
414 	ret = regmap_bulk_write(rv3029->regmap, RV3029_A_SC, regs,
415 				RV3029_ALARM_SECTION_LEN);
416 	if (ret < 0)
417 		return ret;
418 
419 	return rv3029_alarm_irq_enable(dev, alarm->enabled);
420 }
421 
422 static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
423 {
424 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
425 	u8 regs[8];
426 	int ret;
427 
428 	regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
429 	regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
430 	regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
431 	regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
432 	regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
433 	regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
434 	regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
435 
436 	ret = regmap_bulk_write(rv3029->regmap, RV3029_W_SEC, regs,
437 				RV3029_WATCH_SECTION_LEN);
438 	if (ret < 0)
439 		return ret;
440 
441 	/* clear PON and VLOW2 bits */
442 	return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
443 				  RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
444 }
445 
446 static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
447 {
448 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
449 	unsigned long vl = 0;
450 	int sr, ret = 0;
451 
452 	switch (cmd) {
453 	case RTC_VL_READ:
454 		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
455 		if (ret < 0)
456 			return ret;
457 
458 		if (sr & RV3029_STATUS_VLOW1)
459 			vl = RTC_VL_ACCURACY_LOW;
460 
461 		if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
462 			vl |= RTC_VL_DATA_INVALID;
463 
464 		return put_user(vl, (unsigned int __user *)arg);
465 
466 	case RTC_VL_CLR:
467 		return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
468 					  RV3029_STATUS_VLOW1, 0);
469 
470 	default:
471 		return -ENOIOCTLCMD;
472 	}
473 }
474 
475 static int rv3029_nvram_write(void *priv, unsigned int offset, void *val,
476 			      size_t bytes)
477 {
478 	return regmap_bulk_write(priv, RV3029_RAM_PAGE + offset, val, bytes);
479 }
480 
481 static int rv3029_nvram_read(void *priv, unsigned int offset, void *val,
482 			     size_t bytes)
483 {
484 	return regmap_bulk_read(priv, RV3029_RAM_PAGE + offset, val, bytes);
485 }
486 
487 static const struct rv3029_trickle_tab_elem {
488 	u32 r;		/* resistance in ohms */
489 	u8 conf;	/* trickle config bits */
490 } rv3029_trickle_tab[] = {
491 	{
492 		.r	= 1076,
493 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
494 			  RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
495 	}, {
496 		.r	= 1091,
497 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
498 			  RV3029_TRICKLE_20K,
499 	}, {
500 		.r	= 1137,
501 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
502 			  RV3029_TRICKLE_80K,
503 	}, {
504 		.r	= 1154,
505 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
506 	}, {
507 		.r	= 1371,
508 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
509 			  RV3029_TRICKLE_80K,
510 	}, {
511 		.r	= 1395,
512 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
513 	}, {
514 		.r	= 1472,
515 		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
516 	}, {
517 		.r	= 1500,
518 		.conf	= RV3029_TRICKLE_1K,
519 	}, {
520 		.r	= 3810,
521 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
522 			  RV3029_TRICKLE_80K,
523 	}, {
524 		.r	= 4000,
525 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
526 	}, {
527 		.r	= 4706,
528 		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
529 	}, {
530 		.r	= 5000,
531 		.conf	= RV3029_TRICKLE_5K,
532 	}, {
533 		.r	= 16000,
534 		.conf	= RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
535 	}, {
536 		.r	= 20000,
537 		.conf	= RV3029_TRICKLE_20K,
538 	}, {
539 		.r	= 80000,
540 		.conf	= RV3029_TRICKLE_80K,
541 	},
542 };
543 
544 static void rv3029_trickle_config(struct device *dev)
545 {
546 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
547 	struct device_node *of_node = dev->of_node;
548 	const struct rv3029_trickle_tab_elem *elem;
549 	int i, err;
550 	u32 ohms;
551 	u8 trickle_set_bits;
552 
553 	if (!of_node)
554 		return;
555 
556 	/* Configure the trickle charger. */
557 	err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
558 	if (err) {
559 		/* Disable trickle charger. */
560 		trickle_set_bits = 0;
561 	} else {
562 		/* Enable trickle charger. */
563 		for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
564 			elem = &rv3029_trickle_tab[i];
565 			if (elem->r >= ohms)
566 				break;
567 		}
568 		trickle_set_bits = elem->conf;
569 		dev_info(dev,
570 			 "Trickle charger enabled at %d ohms resistance.\n",
571 			 elem->r);
572 	}
573 	err = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
574 					RV3029_TRICKLE_MASK,
575 					trickle_set_bits);
576 	if (err < 0)
577 		dev_err(dev, "Failed to update trickle charger config\n");
578 }
579 
580 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
581 
582 static int rv3029_read_temp(struct rv3029_data *rv3029, int *temp_mC)
583 {
584 	unsigned int temp;
585 	int ret;
586 
587 	ret = regmap_read(rv3029->regmap, RV3029_TEMP_PAGE, &temp);
588 	if (ret < 0)
589 		return ret;
590 
591 	*temp_mC = ((int)temp - 60) * 1000;
592 
593 	return 0;
594 }
595 
596 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
597 				      struct device_attribute *attr,
598 				      char *buf)
599 {
600 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
601 	int ret, temp_mC;
602 
603 	ret = rv3029_read_temp(rv3029, &temp_mC);
604 	if (ret < 0)
605 		return ret;
606 
607 	return sprintf(buf, "%d\n", temp_mC);
608 }
609 
610 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
611 						struct device_attribute *attr,
612 						const char *buf,
613 						size_t count)
614 {
615 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
616 	unsigned int th_set_bits = 0;
617 	unsigned long interval_ms;
618 	int ret;
619 
620 	ret = kstrtoul(buf, 10, &interval_ms);
621 	if (ret < 0)
622 		return ret;
623 
624 	if (interval_ms != 0) {
625 		th_set_bits |= RV3029_EECTRL_THE;
626 		if (interval_ms >= 16000)
627 			th_set_bits |= RV3029_EECTRL_THP;
628 	}
629 	ret = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
630 					RV3029_EECTRL_THE | RV3029_EECTRL_THP,
631 					th_set_bits);
632 	if (ret < 0)
633 		return ret;
634 
635 	return count;
636 }
637 
638 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
639 						 struct device_attribute *attr,
640 						 char *buf)
641 {
642 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
643 	int ret, interval_ms;
644 	u8 eectrl;
645 
646 	ret = rv3029_eeprom_read(rv3029, RV3029_CONTROL_E2P_EECTRL,
647 				 &eectrl, 1);
648 	if (ret < 0)
649 		return ret;
650 
651 	if (eectrl & RV3029_EECTRL_THE) {
652 		if (eectrl & RV3029_EECTRL_THP)
653 			interval_ms = 16000;
654 		else
655 			interval_ms = 1000;
656 	} else {
657 		interval_ms = 0;
658 	}
659 
660 	return sprintf(buf, "%d\n", interval_ms);
661 }
662 
663 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
664 			  NULL, 0);
665 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
666 			  rv3029_hwmon_show_update_interval,
667 			  rv3029_hwmon_set_update_interval, 0);
668 
669 static struct attribute *rv3029_hwmon_attrs[] = {
670 	&sensor_dev_attr_temp1_input.dev_attr.attr,
671 	&sensor_dev_attr_update_interval.dev_attr.attr,
672 	NULL,
673 };
674 ATTRIBUTE_GROUPS(rv3029_hwmon);
675 
676 static void rv3029_hwmon_register(struct device *dev, const char *name)
677 {
678 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
679 	struct device *hwmon_dev;
680 
681 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
682 							   rv3029_hwmon_groups);
683 	if (IS_ERR(hwmon_dev)) {
684 		dev_warn(dev, "unable to register hwmon device %ld\n",
685 			 PTR_ERR(hwmon_dev));
686 	}
687 }
688 
689 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
690 
691 static void rv3029_hwmon_register(struct device *dev, const char *name)
692 {
693 }
694 
695 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
696 
697 static struct rtc_class_ops rv3029_rtc_ops = {
698 	.read_time	= rv3029_read_time,
699 	.set_time	= rv3029_set_time,
700 	.ioctl		= rv3029_ioctl,
701 };
702 
703 static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
704 			const char *name)
705 {
706 	struct rv3029_data *rv3029;
707 	struct nvmem_config nvmem_cfg = {
708 		.name = "rv3029_nvram",
709 		.word_size = 1,
710 		.stride = 1,
711 		.size = RV3029_RAM_SECTION_LEN,
712 		.type = NVMEM_TYPE_BATTERY_BACKED,
713 		.reg_read = rv3029_nvram_read,
714 		.reg_write = rv3029_nvram_write,
715 	};
716 	int rc = 0;
717 
718 	rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
719 	if (!rv3029)
720 		return -ENOMEM;
721 
722 	rv3029->regmap = regmap;
723 	rv3029->irq = irq;
724 	rv3029->dev = dev;
725 	dev_set_drvdata(dev, rv3029);
726 
727 	rv3029_trickle_config(dev);
728 	rv3029_hwmon_register(dev, name);
729 
730 	rv3029->rtc = devm_rtc_allocate_device(dev);
731 	if (IS_ERR(rv3029->rtc))
732 		return PTR_ERR(rv3029->rtc);
733 
734 	if (rv3029->irq > 0) {
735 		rc = devm_request_threaded_irq(dev, rv3029->irq,
736 					       NULL, rv3029_handle_irq,
737 					       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
738 					       "rv3029", dev);
739 		if (rc) {
740 			dev_warn(dev, "unable to request IRQ, alarms disabled\n");
741 			rv3029->irq = 0;
742 		} else {
743 			rv3029_rtc_ops.read_alarm = rv3029_read_alarm;
744 			rv3029_rtc_ops.set_alarm = rv3029_set_alarm;
745 			rv3029_rtc_ops.alarm_irq_enable = rv3029_alarm_irq_enable;
746 		}
747 	}
748 
749 	rv3029->rtc->ops = &rv3029_rtc_ops;
750 	rv3029->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
751 	rv3029->rtc->range_max = RTC_TIMESTAMP_END_2079;
752 
753 	rc = rtc_register_device(rv3029->rtc);
754 	if (rc)
755 		return rc;
756 
757 	nvmem_cfg.priv = rv3029->regmap;
758 	rtc_nvmem_register(rv3029->rtc, &nvmem_cfg);
759 
760 	return 0;
761 }
762 
763 static const struct regmap_range rv3029_holes_range[] = {
764 	regmap_reg_range(0x05, 0x07),
765 	regmap_reg_range(0x0f, 0x0f),
766 	regmap_reg_range(0x17, 0x17),
767 	regmap_reg_range(0x1a, 0x1f),
768 	regmap_reg_range(0x21, 0x27),
769 	regmap_reg_range(0x34, 0x37),
770 };
771 
772 static const struct regmap_access_table rv3029_regs = {
773 	.no_ranges =	rv3029_holes_range,
774 	.n_no_ranges =	ARRAY_SIZE(rv3029_holes_range),
775 };
776 
777 static const struct regmap_config config = {
778 	.reg_bits = 8,
779 	.val_bits = 8,
780 	.rd_table = &rv3029_regs,
781 	.wr_table = &rv3029_regs,
782 	.max_register = 0x3f,
783 };
784 
785 #if IS_ENABLED(CONFIG_I2C)
786 
787 static int rv3029_i2c_probe(struct i2c_client *client,
788 			    const struct i2c_device_id *id)
789 {
790 	struct regmap *regmap;
791 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
792 				     I2C_FUNC_SMBUS_BYTE)) {
793 		dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
794 		return -ENODEV;
795 	}
796 
797 	regmap = devm_regmap_init_i2c(client, &config);
798 	if (IS_ERR(regmap))
799 		return PTR_ERR(regmap);
800 
801 	return rv3029_probe(&client->dev, regmap, client->irq, client->name);
802 }
803 
804 static const struct i2c_device_id rv3029_id[] = {
805 	{ "rv3029", 0 },
806 	{ "rv3029c2", 0 },
807 	{ }
808 };
809 MODULE_DEVICE_TABLE(i2c, rv3029_id);
810 
811 static const struct of_device_id rv3029_of_match[] = {
812 	{ .compatible = "microcrystal,rv3029" },
813 	{ }
814 };
815 MODULE_DEVICE_TABLE(of, rv3029_of_match);
816 
817 static struct i2c_driver rv3029_driver = {
818 	.driver = {
819 		.name = "rv3029",
820 		.of_match_table = of_match_ptr(rv3029_of_match),
821 	},
822 	.probe		= rv3029_i2c_probe,
823 	.id_table	= rv3029_id,
824 };
825 
826 static int __init rv3029_register_driver(void)
827 {
828 	return i2c_add_driver(&rv3029_driver);
829 }
830 
831 static void rv3029_unregister_driver(void)
832 {
833 	i2c_del_driver(&rv3029_driver);
834 }
835 
836 #else
837 
838 static int __init rv3029_register_driver(void)
839 {
840 	return 0;
841 }
842 
843 static void rv3029_unregister_driver(void)
844 {
845 }
846 
847 #endif
848 
849 #if IS_ENABLED(CONFIG_SPI_MASTER)
850 
851 static int rv3049_probe(struct spi_device *spi)
852 {
853 	struct regmap *regmap;
854 
855 	regmap = devm_regmap_init_spi(spi, &config);
856 	if (IS_ERR(regmap))
857 		return PTR_ERR(regmap);
858 
859 	return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
860 }
861 
862 static struct spi_driver rv3049_driver = {
863 	.driver = {
864 		.name    = "rv3049",
865 	},
866 	.probe   = rv3049_probe,
867 };
868 
869 static int __init rv3049_register_driver(void)
870 {
871 	return spi_register_driver(&rv3049_driver);
872 }
873 
874 static void __exit rv3049_unregister_driver(void)
875 {
876 	spi_unregister_driver(&rv3049_driver);
877 }
878 
879 #else
880 
881 static int __init rv3049_register_driver(void)
882 {
883 	return 0;
884 }
885 
886 static void __exit rv3049_unregister_driver(void)
887 {
888 }
889 
890 #endif
891 
892 static int __init rv30x9_init(void)
893 {
894 	int ret;
895 
896 	ret = rv3029_register_driver();
897 	if (ret)
898 		return ret;
899 
900 	ret = rv3049_register_driver();
901 	if (ret)
902 		rv3029_unregister_driver();
903 
904 	return ret;
905 }
906 module_init(rv30x9_init)
907 
908 static void __exit rv30x9_exit(void)
909 {
910 	rv3049_unregister_driver();
911 	rv3029_unregister_driver();
912 }
913 module_exit(rv30x9_exit)
914 
915 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
916 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
917 MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
918 MODULE_LICENSE("GPL");
919 MODULE_ALIAS("spi:rv3049");
920