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1/*
2 * Micro Crystal RV-3029 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/bcd.h>
18#include <linux/rtc.h>
19#include <linux/delay.h>
20#include <linux/of.h>
21#include <linux/hwmon.h>
22#include <linux/hwmon-sysfs.h>
23
24
25/* Register map */
26/* control section */
27#define RV3029_ONOFF_CTRL 0x00
28#define RV3029_ONOFF_CTRL_WE BIT(0)
29#define RV3029_ONOFF_CTRL_TE BIT(1)
30#define RV3029_ONOFF_CTRL_TAR BIT(2)
31#define RV3029_ONOFF_CTRL_EERE BIT(3)
32#define RV3029_ONOFF_CTRL_SRON BIT(4)
33#define RV3029_ONOFF_CTRL_TD0 BIT(5)
34#define RV3029_ONOFF_CTRL_TD1 BIT(6)
35#define RV3029_ONOFF_CTRL_CLKINT BIT(7)
36#define RV3029_IRQ_CTRL 0x01
37#define RV3029_IRQ_CTRL_AIE BIT(0)
38#define RV3029_IRQ_CTRL_TIE BIT(1)
39#define RV3029_IRQ_CTRL_V1IE BIT(2)
40#define RV3029_IRQ_CTRL_V2IE BIT(3)
41#define RV3029_IRQ_CTRL_SRIE BIT(4)
42#define RV3029_IRQ_FLAGS 0x02
43#define RV3029_IRQ_FLAGS_AF BIT(0)
44#define RV3029_IRQ_FLAGS_TF BIT(1)
45#define RV3029_IRQ_FLAGS_V1IF BIT(2)
46#define RV3029_IRQ_FLAGS_V2IF BIT(3)
47#define RV3029_IRQ_FLAGS_SRF BIT(4)
48#define RV3029_STATUS 0x03
49#define RV3029_STATUS_VLOW1 BIT(2)
50#define RV3029_STATUS_VLOW2 BIT(3)
51#define RV3029_STATUS_SR BIT(4)
52#define RV3029_STATUS_PON BIT(5)
53#define RV3029_STATUS_EEBUSY BIT(7)
54#define RV3029_RST_CTRL 0x04
55#define RV3029_RST_CTRL_SYSR BIT(4)
56#define RV3029_CONTROL_SECTION_LEN 0x05
57
58/* watch section */
59#define RV3029_W_SEC 0x08
60#define RV3029_W_MINUTES 0x09
61#define RV3029_W_HOURS 0x0A
62#define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
63#define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
64#define RV3029_W_DATE 0x0B
65#define RV3029_W_DAYS 0x0C
66#define RV3029_W_MONTHS 0x0D
67#define RV3029_W_YEARS 0x0E
68#define RV3029_WATCH_SECTION_LEN 0x07
69
70/* alarm section */
71#define RV3029_A_SC 0x10
72#define RV3029_A_MN 0x11
73#define RV3029_A_HR 0x12
74#define RV3029_A_DT 0x13
75#define RV3029_A_DW 0x14
76#define RV3029_A_MO 0x15
77#define RV3029_A_YR 0x16
78#define RV3029_ALARM_SECTION_LEN 0x07
79
80/* timer section */
81#define RV3029_TIMER_LOW 0x18
82#define RV3029_TIMER_HIGH 0x19
83
84/* temperature section */
85#define RV3029_TEMP_PAGE 0x20
86
87/* eeprom data section */
88#define RV3029_E2P_EEDATA1 0x28
89#define RV3029_E2P_EEDATA2 0x29
90#define RV3029_E2PDATA_SECTION_LEN 0x02
91
92/* eeprom control section */
93#define RV3029_CONTROL_E2P_EECTRL 0x30
94#define RV3029_EECTRL_THP BIT(0) /* temp scan interval */
95#define RV3029_EECTRL_THE BIT(1) /* thermometer enable */
96#define RV3029_EECTRL_FD0 BIT(2) /* CLKOUT */
97#define RV3029_EECTRL_FD1 BIT(3) /* CLKOUT */
98#define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
99#define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
100#define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
101#define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
102#define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
103 RV3029_TRICKLE_5K |\
104 RV3029_TRICKLE_20K |\
105 RV3029_TRICKLE_80K)
106#define RV3029_TRICKLE_SHIFT 4
107#define RV3029_CONTROL_E2P_XOFFS 0x31 /* XTAL offset */
108#define RV3029_CONTROL_E2P_XOFFS_SIGN BIT(7) /* Sign: 1->pos, 0->neg */
109#define RV3029_CONTROL_E2P_QCOEF 0x32 /* XTAL temp drift coef */
110#define RV3029_CONTROL_E2P_TURNOVER 0x33 /* XTAL turnover temp (in *C) */
111#define RV3029_CONTROL_E2P_TOV_MASK 0x3F /* XTAL turnover temp mask */
112
113/* user ram section */
114#define RV3029_USR1_RAM_PAGE 0x38
115#define RV3029_USR1_SECTION_LEN 0x04
116#define RV3029_USR2_RAM_PAGE 0x3C
117#define RV3029_USR2_SECTION_LEN 0x04
118
119static int
120rv3029_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf,
121 unsigned len)
122{
123 int ret;
124
125 if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
126 (reg + len > RV3029_USR1_RAM_PAGE + 8))
127 return -EINVAL;
128
129 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
130 if (ret < 0)
131 return ret;
132 if (ret < len)
133 return -EIO;
134 return 0;
135}
136
137static int
138rv3029_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[],
139 unsigned len)
140{
141 if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
142 (reg + len > RV3029_USR1_RAM_PAGE + 8))
143 return -EINVAL;
144
145 return i2c_smbus_write_i2c_block_data(client, reg, len, buf);
146}
147
148static int
149rv3029_i2c_update_bits(struct i2c_client *client, u8 reg, u8 mask, u8 set)
150{
151 u8 buf;
152 int ret;
153
154 ret = rv3029_i2c_read_regs(client, reg, &buf, 1);
155 if (ret < 0)
156 return ret;
157 buf &= ~mask;
158 buf |= set & mask;
159 ret = rv3029_i2c_write_regs(client, reg, &buf, 1);
160 if (ret < 0)
161 return ret;
162
163 return 0;
164}
165
166static int
167rv3029_i2c_get_sr(struct i2c_client *client, u8 *buf)
168{
169 int ret = rv3029_i2c_read_regs(client, RV3029_STATUS, buf, 1);
170
171 if (ret < 0)
172 return -EIO;
173 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
174 return 0;
175}
176
177static int
178rv3029_i2c_set_sr(struct i2c_client *client, u8 val)
179{
180 u8 buf[1];
181 int sr;
182
183 buf[0] = val;
184 sr = rv3029_i2c_write_regs(client, RV3029_STATUS, buf, 1);
185 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
186 if (sr < 0)
187 return -EIO;
188 return 0;
189}
190
191static int rv3029_eeprom_busywait(struct i2c_client *client)
192{
193 int i, ret;
194 u8 sr;
195
196 for (i = 100; i > 0; i--) {
197 ret = rv3029_i2c_get_sr(client, &sr);
198 if (ret < 0)
199 break;
200 if (!(sr & RV3029_STATUS_EEBUSY))
201 break;
202 usleep_range(1000, 10000);
203 }
204 if (i <= 0) {
205 dev_err(&client->dev, "EEPROM busy wait timeout.\n");
206 return -ETIMEDOUT;
207 }
208
209 return ret;
210}
211
212static int rv3029_eeprom_exit(struct i2c_client *client)
213{
214 /* Re-enable eeprom refresh */
215 return rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL,
216 RV3029_ONOFF_CTRL_EERE,
217 RV3029_ONOFF_CTRL_EERE);
218}
219
220static int rv3029_eeprom_enter(struct i2c_client *client)
221{
222 int ret;
223 u8 sr;
224
225 /* Check whether we are in the allowed voltage range. */
226 ret = rv3029_i2c_get_sr(client, &sr);
227 if (ret < 0)
228 return ret;
229 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
230 /* We clear the bits and retry once just in case
231 * we had a brown out in early startup.
232 */
233 sr &= ~RV3029_STATUS_VLOW1;
234 sr &= ~RV3029_STATUS_VLOW2;
235 ret = rv3029_i2c_set_sr(client, sr);
236 if (ret < 0)
237 return ret;
238 usleep_range(1000, 10000);
239 ret = rv3029_i2c_get_sr(client, &sr);
240 if (ret < 0)
241 return ret;
242 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
243 dev_err(&client->dev,
244 "Supply voltage is too low to safely access the EEPROM.\n");
245 return -ENODEV;
246 }
247 }
248
249 /* Disable eeprom refresh. */
250 ret = rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL,
251 RV3029_ONOFF_CTRL_EERE, 0);
252 if (ret < 0)
253 return ret;
254
255 /* Wait for any previous eeprom accesses to finish. */
256 ret = rv3029_eeprom_busywait(client);
257 if (ret < 0)
258 rv3029_eeprom_exit(client);
259
260 return ret;
261}
262
263static int rv3029_eeprom_read(struct i2c_client *client, u8 reg,
264 u8 buf[], size_t len)
265{
266 int ret, err;
267
268 err = rv3029_eeprom_enter(client);
269 if (err < 0)
270 return err;
271
272 ret = rv3029_i2c_read_regs(client, reg, buf, len);
273
274 err = rv3029_eeprom_exit(client);
275 if (err < 0)
276 return err;
277
278 return ret;
279}
280
281static int rv3029_eeprom_write(struct i2c_client *client, u8 reg,
282 u8 const buf[], size_t len)
283{
284 int ret, err;
285 size_t i;
286 u8 tmp;
287
288 err = rv3029_eeprom_enter(client);
289 if (err < 0)
290 return err;
291
292 for (i = 0; i < len; i++, reg++) {
293 ret = rv3029_i2c_read_regs(client, reg, &tmp, 1);
294 if (ret < 0)
295 break;
296 if (tmp != buf[i]) {
297 ret = rv3029_i2c_write_regs(client, reg, &buf[i], 1);
298 if (ret < 0)
299 break;
300 }
301 ret = rv3029_eeprom_busywait(client);
302 if (ret < 0)
303 break;
304 }
305
306 err = rv3029_eeprom_exit(client);
307 if (err < 0)
308 return err;
309
310 return ret;
311}
312
313static int rv3029_eeprom_update_bits(struct i2c_client *client,
314 u8 reg, u8 mask, u8 set)
315{
316 u8 buf;
317 int ret;
318
319 ret = rv3029_eeprom_read(client, reg, &buf, 1);
320 if (ret < 0)
321 return ret;
322 buf &= ~mask;
323 buf |= set & mask;
324 ret = rv3029_eeprom_write(client, reg, &buf, 1);
325 if (ret < 0)
326 return ret;
327
328 return 0;
329}
330
331static int
332rv3029_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
333{
334 u8 buf[1];
335 int ret;
336 u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
337
338 ret = rv3029_i2c_get_sr(client, buf);
339 if (ret < 0) {
340 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
341 return -EIO;
342 }
343
344 ret = rv3029_i2c_read_regs(client, RV3029_W_SEC, regs,
345 RV3029_WATCH_SECTION_LEN);
346 if (ret < 0) {
347 dev_err(&client->dev, "%s: reading RTC section failed\n",
348 __func__);
349 return ret;
350 }
351
352 tm->tm_sec = bcd2bin(regs[RV3029_W_SEC-RV3029_W_SEC]);
353 tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES-RV3029_W_SEC]);
354
355 /* HR field has a more complex interpretation */
356 {
357 const u8 _hr = regs[RV3029_W_HOURS-RV3029_W_SEC];
358
359 if (_hr & RV3029_REG_HR_12_24) {
360 /* 12h format */
361 tm->tm_hour = bcd2bin(_hr & 0x1f);
362 if (_hr & RV3029_REG_HR_PM) /* PM flag set */
363 tm->tm_hour += 12;
364 } else /* 24h format */
365 tm->tm_hour = bcd2bin(_hr & 0x3f);
366 }
367
368 tm->tm_mday = bcd2bin(regs[RV3029_W_DATE-RV3029_W_SEC]);
369 tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS-RV3029_W_SEC]) - 1;
370 tm->tm_year = bcd2bin(regs[RV3029_W_YEARS-RV3029_W_SEC]) + 100;
371 tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS-RV3029_W_SEC]) - 1;
372
373 return 0;
374}
375
376static int rv3029_rtc_read_time(struct device *dev, struct rtc_time *tm)
377{
378 return rv3029_i2c_read_time(to_i2c_client(dev), tm);
379}
380
381static int
382rv3029_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
383{
384 struct rtc_time *const tm = &alarm->time;
385 int ret;
386 u8 regs[8];
387
388 ret = rv3029_i2c_get_sr(client, regs);
389 if (ret < 0) {
390 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
391 return -EIO;
392 }
393
394 ret = rv3029_i2c_read_regs(client, RV3029_A_SC, regs,
395 RV3029_ALARM_SECTION_LEN);
396
397 if (ret < 0) {
398 dev_err(&client->dev, "%s: reading alarm section failed\n",
399 __func__);
400 return ret;
401 }
402
403 tm->tm_sec = bcd2bin(regs[RV3029_A_SC-RV3029_A_SC] & 0x7f);
404 tm->tm_min = bcd2bin(regs[RV3029_A_MN-RV3029_A_SC] & 0x7f);
405 tm->tm_hour = bcd2bin(regs[RV3029_A_HR-RV3029_A_SC] & 0x3f);
406 tm->tm_mday = bcd2bin(regs[RV3029_A_DT-RV3029_A_SC] & 0x3f);
407 tm->tm_mon = bcd2bin(regs[RV3029_A_MO-RV3029_A_SC] & 0x1f) - 1;
408 tm->tm_year = bcd2bin(regs[RV3029_A_YR-RV3029_A_SC] & 0x7f) + 100;
409 tm->tm_wday = bcd2bin(regs[RV3029_A_DW-RV3029_A_SC] & 0x07) - 1;
410
411 return 0;
412}
413
414static int
415rv3029_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
416{
417 return rv3029_i2c_read_alarm(to_i2c_client(dev), alarm);
418}
419
420static int rv3029_rtc_i2c_alarm_set_irq(struct i2c_client *client,
421 int enable)
422{
423 int ret;
424
425 /* enable/disable AIE irq */
426 ret = rv3029_i2c_update_bits(client, RV3029_IRQ_CTRL,
427 RV3029_IRQ_CTRL_AIE,
428 (enable ? RV3029_IRQ_CTRL_AIE : 0));
429 if (ret < 0) {
430 dev_err(&client->dev, "can't update INT reg\n");
431 return ret;
432 }
433
434 return 0;
435}
436
437static int rv3029_rtc_i2c_set_alarm(struct i2c_client *client,
438 struct rtc_wkalrm *alarm)
439{
440 struct rtc_time *const tm = &alarm->time;
441 int ret;
442 u8 regs[8];
443
444 /*
445 * The clock has an 8 bit wide bcd-coded register (they never learn)
446 * for the year. tm_year is an offset from 1900 and we are interested
447 * in the 2000-2099 range, so any value less than 100 is invalid.
448 */
449 if (tm->tm_year < 100)
450 return -EINVAL;
451
452 ret = rv3029_i2c_get_sr(client, regs);
453 if (ret < 0) {
454 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
455 return -EIO;
456 }
457 regs[RV3029_A_SC-RV3029_A_SC] = bin2bcd(tm->tm_sec & 0x7f);
458 regs[RV3029_A_MN-RV3029_A_SC] = bin2bcd(tm->tm_min & 0x7f);
459 regs[RV3029_A_HR-RV3029_A_SC] = bin2bcd(tm->tm_hour & 0x3f);
460 regs[RV3029_A_DT-RV3029_A_SC] = bin2bcd(tm->tm_mday & 0x3f);
461 regs[RV3029_A_MO-RV3029_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1);
462 regs[RV3029_A_DW-RV3029_A_SC] = bin2bcd((tm->tm_wday & 7) - 1);
463 regs[RV3029_A_YR-RV3029_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100);
464
465 ret = rv3029_i2c_write_regs(client, RV3029_A_SC, regs,
466 RV3029_ALARM_SECTION_LEN);
467 if (ret < 0)
468 return ret;
469
470 if (alarm->enabled) {
471 /* clear AF flag */
472 ret = rv3029_i2c_update_bits(client, RV3029_IRQ_FLAGS,
473 RV3029_IRQ_FLAGS_AF, 0);
474 if (ret < 0) {
475 dev_err(&client->dev, "can't clear alarm flag\n");
476 return ret;
477 }
478 /* enable AIE irq */
479 ret = rv3029_rtc_i2c_alarm_set_irq(client, 1);
480 if (ret)
481 return ret;
482
483 dev_dbg(&client->dev, "alarm IRQ armed\n");
484 } else {
485 /* disable AIE irq */
486 ret = rv3029_rtc_i2c_alarm_set_irq(client, 0);
487 if (ret)
488 return ret;
489
490 dev_dbg(&client->dev, "alarm IRQ disabled\n");
491 }
492
493 return 0;
494}
495
496static int rv3029_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
497{
498 return rv3029_rtc_i2c_set_alarm(to_i2c_client(dev), alarm);
499}
500
501static int
502rv3029_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
503{
504 u8 regs[8];
505 int ret;
506
507 /*
508 * The clock has an 8 bit wide bcd-coded register (they never learn)
509 * for the year. tm_year is an offset from 1900 and we are interested
510 * in the 2000-2099 range, so any value less than 100 is invalid.
511 */
512 if (tm->tm_year < 100)
513 return -EINVAL;
514
515 regs[RV3029_W_SEC-RV3029_W_SEC] = bin2bcd(tm->tm_sec);
516 regs[RV3029_W_MINUTES-RV3029_W_SEC] = bin2bcd(tm->tm_min);
517 regs[RV3029_W_HOURS-RV3029_W_SEC] = bin2bcd(tm->tm_hour);
518 regs[RV3029_W_DATE-RV3029_W_SEC] = bin2bcd(tm->tm_mday);
519 regs[RV3029_W_MONTHS-RV3029_W_SEC] = bin2bcd(tm->tm_mon+1);
520 regs[RV3029_W_DAYS-RV3029_W_SEC] = bin2bcd((tm->tm_wday & 7)+1);
521 regs[RV3029_W_YEARS-RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
522
523 ret = rv3029_i2c_write_regs(client, RV3029_W_SEC, regs,
524 RV3029_WATCH_SECTION_LEN);
525 if (ret < 0)
526 return ret;
527
528 ret = rv3029_i2c_get_sr(client, regs);
529 if (ret < 0) {
530 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
531 return ret;
532 }
533 /* clear PON bit */
534 ret = rv3029_i2c_set_sr(client, (regs[0] & ~RV3029_STATUS_PON));
535 if (ret < 0) {
536 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
537 return ret;
538 }
539
540 return 0;
541}
542
543static int rv3029_rtc_set_time(struct device *dev, struct rtc_time *tm)
544{
545 return rv3029_i2c_set_time(to_i2c_client(dev), tm);
546}
547
548static const struct rv3029_trickle_tab_elem {
549 u32 r; /* resistance in ohms */
550 u8 conf; /* trickle config bits */
551} rv3029_trickle_tab[] = {
552 {
553 .r = 1076,
554 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
555 RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
556 }, {
557 .r = 1091,
558 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
559 RV3029_TRICKLE_20K,
560 }, {
561 .r = 1137,
562 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
563 RV3029_TRICKLE_80K,
564 }, {
565 .r = 1154,
566 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
567 }, {
568 .r = 1371,
569 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
570 RV3029_TRICKLE_80K,
571 }, {
572 .r = 1395,
573 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
574 }, {
575 .r = 1472,
576 .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
577 }, {
578 .r = 1500,
579 .conf = RV3029_TRICKLE_1K,
580 }, {
581 .r = 3810,
582 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
583 RV3029_TRICKLE_80K,
584 }, {
585 .r = 4000,
586 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
587 }, {
588 .r = 4706,
589 .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
590 }, {
591 .r = 5000,
592 .conf = RV3029_TRICKLE_5K,
593 }, {
594 .r = 16000,
595 .conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
596 }, {
597 .r = 20000,
598 .conf = RV3029_TRICKLE_20K,
599 }, {
600 .r = 80000,
601 .conf = RV3029_TRICKLE_80K,
602 },
603};
604
605static void rv3029_trickle_config(struct i2c_client *client)
606{
607 struct device_node *of_node = client->dev.of_node;
608 const struct rv3029_trickle_tab_elem *elem;
609 int i, err;
610 u32 ohms;
611 u8 trickle_set_bits;
612
613 if (!of_node)
614 return;
615
616 /* Configure the trickle charger. */
617 err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
618 if (err) {
619 /* Disable trickle charger. */
620 trickle_set_bits = 0;
621 } else {
622 /* Enable trickle charger. */
623 for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
624 elem = &rv3029_trickle_tab[i];
625 if (elem->r >= ohms)
626 break;
627 }
628 trickle_set_bits = elem->conf;
629 dev_info(&client->dev,
630 "Trickle charger enabled at %d ohms resistance.\n",
631 elem->r);
632 }
633 err = rv3029_eeprom_update_bits(client, RV3029_CONTROL_E2P_EECTRL,
634 RV3029_TRICKLE_MASK,
635 trickle_set_bits);
636 if (err < 0) {
637 dev_err(&client->dev,
638 "Failed to update trickle charger config\n");
639 }
640}
641
642#ifdef CONFIG_RTC_DRV_RV3029_HWMON
643
644static int rv3029_read_temp(struct i2c_client *client, int *temp_mC)
645{
646 int ret;
647 u8 temp;
648
649 ret = rv3029_i2c_read_regs(client, RV3029_TEMP_PAGE, &temp, 1);
650 if (ret < 0)
651 return ret;
652
653 *temp_mC = ((int)temp - 60) * 1000;
654
655 return 0;
656}
657
658static ssize_t rv3029_hwmon_show_temp(struct device *dev,
659 struct device_attribute *attr,
660 char *buf)
661{
662 struct i2c_client *client = dev_get_drvdata(dev);
663 int ret, temp_mC;
664
665 ret = rv3029_read_temp(client, &temp_mC);
666 if (ret < 0)
667 return ret;
668
669 return sprintf(buf, "%d\n", temp_mC);
670}
671
672static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
673 struct device_attribute *attr,
674 const char *buf,
675 size_t count)
676{
677 struct i2c_client *client = dev_get_drvdata(dev);
678 unsigned long interval_ms;
679 int ret;
680 u8 th_set_bits = 0;
681
682 ret = kstrtoul(buf, 10, &interval_ms);
683 if (ret < 0)
684 return ret;
685
686 if (interval_ms != 0) {
687 th_set_bits |= RV3029_EECTRL_THE;
688 if (interval_ms >= 16000)
689 th_set_bits |= RV3029_EECTRL_THP;
690 }
691 ret = rv3029_eeprom_update_bits(client, RV3029_CONTROL_E2P_EECTRL,
692 RV3029_EECTRL_THE | RV3029_EECTRL_THP,
693 th_set_bits);
694 if (ret < 0)
695 return ret;
696
697 return count;
698}
699
700static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
701 struct device_attribute *attr,
702 char *buf)
703{
704 struct i2c_client *client = dev_get_drvdata(dev);
705 int ret, interval_ms;
706 u8 eectrl;
707
708 ret = rv3029_eeprom_read(client, RV3029_CONTROL_E2P_EECTRL,
709 &eectrl, 1);
710 if (ret < 0)
711 return ret;
712
713 if (eectrl & RV3029_EECTRL_THE) {
714 if (eectrl & RV3029_EECTRL_THP)
715 interval_ms = 16000;
716 else
717 interval_ms = 1000;
718 } else {
719 interval_ms = 0;
720 }
721
722 return sprintf(buf, "%d\n", interval_ms);
723}
724
725static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
726 NULL, 0);
727static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
728 rv3029_hwmon_show_update_interval,
729 rv3029_hwmon_set_update_interval, 0);
730
731static struct attribute *rv3029_hwmon_attrs[] = {
732 &sensor_dev_attr_temp1_input.dev_attr.attr,
733 &sensor_dev_attr_update_interval.dev_attr.attr,
734 NULL,
735};
736ATTRIBUTE_GROUPS(rv3029_hwmon);
737
738static void rv3029_hwmon_register(struct i2c_client *client)
739{
740 struct device *hwmon_dev;
741
742 hwmon_dev = devm_hwmon_device_register_with_groups(
743 &client->dev, client->name, client, rv3029_hwmon_groups);
744 if (IS_ERR(hwmon_dev)) {
745 dev_warn(&client->dev,
746 "unable to register hwmon device %ld\n",
747 PTR_ERR(hwmon_dev));
748 }
749}
750
751#else /* CONFIG_RTC_DRV_RV3029_HWMON */
752
753static void rv3029_hwmon_register(struct i2c_client *client)
754{
755}
756
757#endif /* CONFIG_RTC_DRV_RV3029_HWMON */
758
759static const struct rtc_class_ops rv3029_rtc_ops = {
760 .read_time = rv3029_rtc_read_time,
761 .set_time = rv3029_rtc_set_time,
762 .read_alarm = rv3029_rtc_read_alarm,
763 .set_alarm = rv3029_rtc_set_alarm,
764};
765
766static struct i2c_device_id rv3029_id[] = {
767 { "rv3029", 0 },
768 { "rv3029c2", 0 },
769 { }
770};
771MODULE_DEVICE_TABLE(i2c, rv3029_id);
772
773static int rv3029_probe(struct i2c_client *client,
774 const struct i2c_device_id *id)
775{
776 struct rtc_device *rtc;
777 int rc = 0;
778 u8 buf[1];
779
780 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL))
781 return -ENODEV;
782
783 rc = rv3029_i2c_get_sr(client, buf);
784 if (rc < 0) {
785 dev_err(&client->dev, "reading status failed\n");
786 return rc;
787 }
788
789 rv3029_trickle_config(client);
790 rv3029_hwmon_register(client);
791
792 rtc = devm_rtc_device_register(&client->dev, client->name,
793 &rv3029_rtc_ops, THIS_MODULE);
794
795 if (IS_ERR(rtc))
796 return PTR_ERR(rtc);
797
798 i2c_set_clientdata(client, rtc);
799
800 return 0;
801}
802
803static struct i2c_driver rv3029_driver = {
804 .driver = {
805 .name = "rtc-rv3029c2",
806 },
807 .probe = rv3029_probe,
808 .id_table = rv3029_id,
809};
810
811module_i2c_driver(rv3029_driver);
812
813MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
814MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
815MODULE_DESCRIPTION("Micro Crystal RV3029 RTC driver");
816MODULE_LICENSE("GPL");
1/*
2 * Micro Crystal RV-3029C2 rtc class driver
3 *
4 * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
5 *
6 * based on previously existing rtc class drivers
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * NOTE: Currently this driver only supports the bare minimum for read
13 * and write the RTC and alarms. The extra features provided by this chip
14 * (trickle charger, eeprom, T° compensation) are unavailable.
15 */
16
17#include <linux/module.h>
18#include <linux/i2c.h>
19#include <linux/bcd.h>
20#include <linux/rtc.h>
21
22/* Register map */
23/* control section */
24#define RV3029C2_ONOFF_CTRL 0x00
25#define RV3029C2_IRQ_CTRL 0x01
26#define RV3029C2_IRQ_CTRL_AIE (1 << 0)
27#define RV3029C2_IRQ_FLAGS 0x02
28#define RV3029C2_IRQ_FLAGS_AF (1 << 0)
29#define RV3029C2_STATUS 0x03
30#define RV3029C2_STATUS_VLOW1 (1 << 2)
31#define RV3029C2_STATUS_VLOW2 (1 << 3)
32#define RV3029C2_STATUS_SR (1 << 4)
33#define RV3029C2_STATUS_PON (1 << 5)
34#define RV3029C2_STATUS_EEBUSY (1 << 7)
35#define RV3029C2_RST_CTRL 0x04
36#define RV3029C2_CONTROL_SECTION_LEN 0x05
37
38/* watch section */
39#define RV3029C2_W_SEC 0x08
40#define RV3029C2_W_MINUTES 0x09
41#define RV3029C2_W_HOURS 0x0A
42#define RV3029C2_REG_HR_12_24 (1<<6) /* 24h/12h mode */
43#define RV3029C2_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
44#define RV3029C2_W_DATE 0x0B
45#define RV3029C2_W_DAYS 0x0C
46#define RV3029C2_W_MONTHS 0x0D
47#define RV3029C2_W_YEARS 0x0E
48#define RV3029C2_WATCH_SECTION_LEN 0x07
49
50/* alarm section */
51#define RV3029C2_A_SC 0x10
52#define RV3029C2_A_MN 0x11
53#define RV3029C2_A_HR 0x12
54#define RV3029C2_A_DT 0x13
55#define RV3029C2_A_DW 0x14
56#define RV3029C2_A_MO 0x15
57#define RV3029C2_A_YR 0x16
58#define RV3029C2_ALARM_SECTION_LEN 0x07
59
60/* timer section */
61#define RV3029C2_TIMER_LOW 0x18
62#define RV3029C2_TIMER_HIGH 0x19
63
64/* temperature section */
65#define RV3029C2_TEMP_PAGE 0x20
66
67/* eeprom data section */
68#define RV3029C2_E2P_EEDATA1 0x28
69#define RV3029C2_E2P_EEDATA2 0x29
70
71/* eeprom control section */
72#define RV3029C2_CONTROL_E2P_EECTRL 0x30
73#define RV3029C2_TRICKLE_1K (1<<0) /* 1K resistance */
74#define RV3029C2_TRICKLE_5K (1<<1) /* 5K resistance */
75#define RV3029C2_TRICKLE_20K (1<<2) /* 20K resistance */
76#define RV3029C2_TRICKLE_80K (1<<3) /* 80K resistance */
77#define RV3029C2_CONTROL_E2P_XTALOFFSET 0x31
78#define RV3029C2_CONTROL_E2P_QCOEF 0x32
79#define RV3029C2_CONTROL_E2P_TURNOVER 0x33
80
81/* user ram section */
82#define RV3029C2_USR1_RAM_PAGE 0x38
83#define RV3029C2_USR1_SECTION_LEN 0x04
84#define RV3029C2_USR2_RAM_PAGE 0x3C
85#define RV3029C2_USR2_SECTION_LEN 0x04
86
87static int
88rv3029c2_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf,
89 unsigned len)
90{
91 int ret;
92
93 if ((reg > RV3029C2_USR1_RAM_PAGE + 7) ||
94 (reg + len > RV3029C2_USR1_RAM_PAGE + 8))
95 return -EINVAL;
96
97 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
98 if (ret < 0)
99 return ret;
100 if (ret < len)
101 return -EIO;
102 return 0;
103}
104
105static int
106rv3029c2_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[],
107 unsigned len)
108{
109 if ((reg > RV3029C2_USR1_RAM_PAGE + 7) ||
110 (reg + len > RV3029C2_USR1_RAM_PAGE + 8))
111 return -EINVAL;
112
113 return i2c_smbus_write_i2c_block_data(client, reg, len, buf);
114}
115
116static int
117rv3029c2_i2c_get_sr(struct i2c_client *client, u8 *buf)
118{
119 int ret = rv3029c2_i2c_read_regs(client, RV3029C2_STATUS, buf, 1);
120
121 if (ret < 0)
122 return -EIO;
123 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
124 return 0;
125}
126
127static int
128rv3029c2_i2c_set_sr(struct i2c_client *client, u8 val)
129{
130 u8 buf[1];
131 int sr;
132
133 buf[0] = val;
134 sr = rv3029c2_i2c_write_regs(client, RV3029C2_STATUS, buf, 1);
135 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
136 if (sr < 0)
137 return -EIO;
138 return 0;
139}
140
141static int
142rv3029c2_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
143{
144 u8 buf[1];
145 int ret;
146 u8 regs[RV3029C2_WATCH_SECTION_LEN] = { 0, };
147
148 ret = rv3029c2_i2c_get_sr(client, buf);
149 if (ret < 0) {
150 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
151 return -EIO;
152 }
153
154 ret = rv3029c2_i2c_read_regs(client, RV3029C2_W_SEC , regs,
155 RV3029C2_WATCH_SECTION_LEN);
156 if (ret < 0) {
157 dev_err(&client->dev, "%s: reading RTC section failed\n",
158 __func__);
159 return ret;
160 }
161
162 tm->tm_sec = bcd2bin(regs[RV3029C2_W_SEC-RV3029C2_W_SEC]);
163 tm->tm_min = bcd2bin(regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC]);
164
165 /* HR field has a more complex interpretation */
166 {
167 const u8 _hr = regs[RV3029C2_W_HOURS-RV3029C2_W_SEC];
168 if (_hr & RV3029C2_REG_HR_12_24) {
169 /* 12h format */
170 tm->tm_hour = bcd2bin(_hr & 0x1f);
171 if (_hr & RV3029C2_REG_HR_PM) /* PM flag set */
172 tm->tm_hour += 12;
173 } else /* 24h format */
174 tm->tm_hour = bcd2bin(_hr & 0x3f);
175 }
176
177 tm->tm_mday = bcd2bin(regs[RV3029C2_W_DATE-RV3029C2_W_SEC]);
178 tm->tm_mon = bcd2bin(regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC]) - 1;
179 tm->tm_year = bcd2bin(regs[RV3029C2_W_YEARS-RV3029C2_W_SEC]) + 100;
180 tm->tm_wday = bcd2bin(regs[RV3029C2_W_DAYS-RV3029C2_W_SEC]) - 1;
181
182 return 0;
183}
184
185static int rv3029c2_rtc_read_time(struct device *dev, struct rtc_time *tm)
186{
187 return rv3029c2_i2c_read_time(to_i2c_client(dev), tm);
188}
189
190static int
191rv3029c2_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
192{
193 struct rtc_time *const tm = &alarm->time;
194 int ret;
195 u8 regs[8];
196
197 ret = rv3029c2_i2c_get_sr(client, regs);
198 if (ret < 0) {
199 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
200 return -EIO;
201 }
202
203 ret = rv3029c2_i2c_read_regs(client, RV3029C2_A_SC, regs,
204 RV3029C2_ALARM_SECTION_LEN);
205
206 if (ret < 0) {
207 dev_err(&client->dev, "%s: reading alarm section failed\n",
208 __func__);
209 return ret;
210 }
211
212 tm->tm_sec = bcd2bin(regs[RV3029C2_A_SC-RV3029C2_A_SC] & 0x7f);
213 tm->tm_min = bcd2bin(regs[RV3029C2_A_MN-RV3029C2_A_SC] & 0x7f);
214 tm->tm_hour = bcd2bin(regs[RV3029C2_A_HR-RV3029C2_A_SC] & 0x3f);
215 tm->tm_mday = bcd2bin(regs[RV3029C2_A_DT-RV3029C2_A_SC] & 0x3f);
216 tm->tm_mon = bcd2bin(regs[RV3029C2_A_MO-RV3029C2_A_SC] & 0x1f) - 1;
217 tm->tm_year = bcd2bin(regs[RV3029C2_A_YR-RV3029C2_A_SC] & 0x7f) + 100;
218 tm->tm_wday = bcd2bin(regs[RV3029C2_A_DW-RV3029C2_A_SC] & 0x07) - 1;
219
220 return 0;
221}
222
223static int
224rv3029c2_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
225{
226 return rv3029c2_i2c_read_alarm(to_i2c_client(dev), alarm);
227}
228
229static int rv3029c2_rtc_i2c_alarm_set_irq(struct i2c_client *client,
230 int enable)
231{
232 int ret;
233 u8 buf[1];
234
235 /* enable AIE irq */
236 ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_CTRL, buf, 1);
237 if (ret < 0) {
238 dev_err(&client->dev, "can't read INT reg\n");
239 return ret;
240 }
241 if (enable)
242 buf[0] |= RV3029C2_IRQ_CTRL_AIE;
243 else
244 buf[0] &= ~RV3029C2_IRQ_CTRL_AIE;
245
246 ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_CTRL, buf, 1);
247 if (ret < 0) {
248 dev_err(&client->dev, "can't set INT reg\n");
249 return ret;
250 }
251
252 return 0;
253}
254
255static int rv3029c2_rtc_i2c_set_alarm(struct i2c_client *client,
256 struct rtc_wkalrm *alarm)
257{
258 struct rtc_time *const tm = &alarm->time;
259 int ret;
260 u8 regs[8];
261
262 /*
263 * The clock has an 8 bit wide bcd-coded register (they never learn)
264 * for the year. tm_year is an offset from 1900 and we are interested
265 * in the 2000-2099 range, so any value less than 100 is invalid.
266 */
267 if (tm->tm_year < 100)
268 return -EINVAL;
269
270 ret = rv3029c2_i2c_get_sr(client, regs);
271 if (ret < 0) {
272 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
273 return -EIO;
274 }
275 regs[RV3029C2_A_SC-RV3029C2_A_SC] = bin2bcd(tm->tm_sec & 0x7f);
276 regs[RV3029C2_A_MN-RV3029C2_A_SC] = bin2bcd(tm->tm_min & 0x7f);
277 regs[RV3029C2_A_HR-RV3029C2_A_SC] = bin2bcd(tm->tm_hour & 0x3f);
278 regs[RV3029C2_A_DT-RV3029C2_A_SC] = bin2bcd(tm->tm_mday & 0x3f);
279 regs[RV3029C2_A_MO-RV3029C2_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1);
280 regs[RV3029C2_A_DW-RV3029C2_A_SC] = bin2bcd((tm->tm_wday & 7) - 1);
281 regs[RV3029C2_A_YR-RV3029C2_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100);
282
283 ret = rv3029c2_i2c_write_regs(client, RV3029C2_A_SC, regs,
284 RV3029C2_ALARM_SECTION_LEN);
285 if (ret < 0)
286 return ret;
287
288 if (alarm->enabled) {
289 u8 buf[1];
290
291 /* clear AF flag */
292 ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_FLAGS,
293 buf, 1);
294 if (ret < 0) {
295 dev_err(&client->dev, "can't read alarm flag\n");
296 return ret;
297 }
298 buf[0] &= ~RV3029C2_IRQ_FLAGS_AF;
299 ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_FLAGS,
300 buf, 1);
301 if (ret < 0) {
302 dev_err(&client->dev, "can't set alarm flag\n");
303 return ret;
304 }
305 /* enable AIE irq */
306 ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 1);
307 if (ret)
308 return ret;
309
310 dev_dbg(&client->dev, "alarm IRQ armed\n");
311 } else {
312 /* disable AIE irq */
313 ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 0);
314 if (ret)
315 return ret;
316
317 dev_dbg(&client->dev, "alarm IRQ disabled\n");
318 }
319
320 return 0;
321}
322
323static int rv3029c2_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
324{
325 return rv3029c2_rtc_i2c_set_alarm(to_i2c_client(dev), alarm);
326}
327
328static int
329rv3029c2_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
330{
331 u8 regs[8];
332 int ret;
333
334 /*
335 * The clock has an 8 bit wide bcd-coded register (they never learn)
336 * for the year. tm_year is an offset from 1900 and we are interested
337 * in the 2000-2099 range, so any value less than 100 is invalid.
338 */
339 if (tm->tm_year < 100)
340 return -EINVAL;
341
342 regs[RV3029C2_W_SEC-RV3029C2_W_SEC] = bin2bcd(tm->tm_sec);
343 regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC] = bin2bcd(tm->tm_min);
344 regs[RV3029C2_W_HOURS-RV3029C2_W_SEC] = bin2bcd(tm->tm_hour);
345 regs[RV3029C2_W_DATE-RV3029C2_W_SEC] = bin2bcd(tm->tm_mday);
346 regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC] = bin2bcd(tm->tm_mon+1);
347 regs[RV3029C2_W_DAYS-RV3029C2_W_SEC] = bin2bcd((tm->tm_wday & 7)+1);
348 regs[RV3029C2_W_YEARS-RV3029C2_W_SEC] = bin2bcd(tm->tm_year - 100);
349
350 ret = rv3029c2_i2c_write_regs(client, RV3029C2_W_SEC, regs,
351 RV3029C2_WATCH_SECTION_LEN);
352 if (ret < 0)
353 return ret;
354
355 ret = rv3029c2_i2c_get_sr(client, regs);
356 if (ret < 0) {
357 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
358 return ret;
359 }
360 /* clear PON bit */
361 ret = rv3029c2_i2c_set_sr(client, (regs[0] & ~RV3029C2_STATUS_PON));
362 if (ret < 0) {
363 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
364 return ret;
365 }
366
367 return 0;
368}
369
370static int rv3029c2_rtc_set_time(struct device *dev, struct rtc_time *tm)
371{
372 return rv3029c2_i2c_set_time(to_i2c_client(dev), tm);
373}
374
375static const struct rtc_class_ops rv3029c2_rtc_ops = {
376 .read_time = rv3029c2_rtc_read_time,
377 .set_time = rv3029c2_rtc_set_time,
378 .read_alarm = rv3029c2_rtc_read_alarm,
379 .set_alarm = rv3029c2_rtc_set_alarm,
380};
381
382static struct i2c_device_id rv3029c2_id[] = {
383 { "rv3029c2", 0 },
384 { }
385};
386MODULE_DEVICE_TABLE(i2c, rv3029c2_id);
387
388static int rv3029c2_probe(struct i2c_client *client,
389 const struct i2c_device_id *id)
390{
391 struct rtc_device *rtc;
392 int rc = 0;
393 u8 buf[1];
394
395 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL))
396 return -ENODEV;
397
398 rc = rv3029c2_i2c_get_sr(client, buf);
399 if (rc < 0) {
400 dev_err(&client->dev, "reading status failed\n");
401 return rc;
402 }
403
404 rtc = devm_rtc_device_register(&client->dev, client->name,
405 &rv3029c2_rtc_ops, THIS_MODULE);
406
407 if (IS_ERR(rtc))
408 return PTR_ERR(rtc);
409
410 i2c_set_clientdata(client, rtc);
411
412 return 0;
413}
414
415static struct i2c_driver rv3029c2_driver = {
416 .driver = {
417 .name = "rtc-rv3029c2",
418 },
419 .probe = rv3029c2_probe,
420 .id_table = rv3029c2_id,
421};
422
423module_i2c_driver(rv3029c2_driver);
424
425MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
426MODULE_DESCRIPTION("Micro Crystal RV3029C2 RTC driver");
427MODULE_LICENSE("GPL");