1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <linux/bcd.h>
17#include <linux/i2c.h>
18#include <linux/module.h>
19#include <linux/rtc.h>
20
21#define ABX8XX_REG_HTH 0x00
22#define ABX8XX_REG_SC 0x01
23#define ABX8XX_REG_MN 0x02
24#define ABX8XX_REG_HR 0x03
25#define ABX8XX_REG_DA 0x04
26#define ABX8XX_REG_MO 0x05
27#define ABX8XX_REG_YR 0x06
28#define ABX8XX_REG_WD 0x07
29
30#define ABX8XX_REG_AHTH 0x08
31#define ABX8XX_REG_ASC 0x09
32#define ABX8XX_REG_AMN 0x0a
33#define ABX8XX_REG_AHR 0x0b
34#define ABX8XX_REG_ADA 0x0c
35#define ABX8XX_REG_AMO 0x0d
36#define ABX8XX_REG_AWD 0x0e
37
38#define ABX8XX_REG_STATUS 0x0f
39#define ABX8XX_STATUS_AF BIT(2)
40
41#define ABX8XX_REG_CTRL1 0x10
42#define ABX8XX_CTRL_WRITE BIT(0)
43#define ABX8XX_CTRL_ARST BIT(2)
44#define ABX8XX_CTRL_12_24 BIT(6)
45
46#define ABX8XX_REG_IRQ 0x12
47#define ABX8XX_IRQ_AIE BIT(2)
48#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
49
50#define ABX8XX_REG_CD_TIMER_CTL 0x18
51
52#define ABX8XX_REG_OSC 0x1c
53#define ABX8XX_OSC_FOS BIT(3)
54#define ABX8XX_OSC_BOS BIT(4)
55#define ABX8XX_OSC_ACAL_512 BIT(5)
56#define ABX8XX_OSC_ACAL_1024 BIT(6)
57
58#define ABX8XX_OSC_OSEL BIT(7)
59
60#define ABX8XX_REG_OSS 0x1d
61#define ABX8XX_OSS_OF BIT(1)
62#define ABX8XX_OSS_OMODE BIT(4)
63
64#define ABX8XX_REG_CFG_KEY 0x1f
65#define ABX8XX_CFG_KEY_OSC 0xa1
66#define ABX8XX_CFG_KEY_MISC 0x9d
67
68#define ABX8XX_REG_ID0 0x28
69
70#define ABX8XX_REG_TRICKLE 0x20
71#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
72#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
73#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
74
75static u8 trickle_resistors[] = {0, 3, 6, 11};
76
77enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
78 AB1801, AB1803, AB1804, AB1805, ABX80X};
79
80struct abx80x_cap {
81 u16 pn;
82 bool has_tc;
83};
84
85static struct abx80x_cap abx80x_caps[] = {
86 [AB0801] = {.pn = 0x0801},
87 [AB0803] = {.pn = 0x0803},
88 [AB0804] = {.pn = 0x0804, .has_tc = true},
89 [AB0805] = {.pn = 0x0805, .has_tc = true},
90 [AB1801] = {.pn = 0x1801},
91 [AB1803] = {.pn = 0x1803},
92 [AB1804] = {.pn = 0x1804, .has_tc = true},
93 [AB1805] = {.pn = 0x1805, .has_tc = true},
94 [ABX80X] = {.pn = 0}
95};
96
97static int abx80x_is_rc_mode(struct i2c_client *client)
98{
99 int flags = 0;
100
101 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
102 if (flags < 0) {
103 dev_err(&client->dev,
104 "Failed to read autocalibration attribute\n");
105 return flags;
106 }
107
108 return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
109}
110
111static int abx80x_enable_trickle_charger(struct i2c_client *client,
112 u8 trickle_cfg)
113{
114 int err;
115
116
117
118
119
120 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
121 ABX8XX_CFG_KEY_MISC);
122 if (err < 0) {
123 dev_err(&client->dev, "Unable to write configuration key\n");
124 return -EIO;
125 }
126
127 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
128 ABX8XX_TRICKLE_CHARGE_ENABLE |
129 trickle_cfg);
130 if (err < 0) {
131 dev_err(&client->dev, "Unable to write trickle register\n");
132 return -EIO;
133 }
134
135 return 0;
136}
137
138static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
139{
140 struct i2c_client *client = to_i2c_client(dev);
141 unsigned char buf[8];
142 int err, flags, rc_mode = 0;
143
144
145 rc_mode = abx80x_is_rc_mode(client);
146 if (rc_mode < 0)
147 return rc_mode;
148
149 if (!rc_mode) {
150 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
151 if (flags < 0)
152 return flags;
153
154 if (flags & ABX8XX_OSS_OF) {
155 dev_err(dev, "Oscillator failure, data is invalid.\n");
156 return -EINVAL;
157 }
158 }
159
160 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
161 sizeof(buf), buf);
162 if (err < 0) {
163 dev_err(&client->dev, "Unable to read date\n");
164 return -EIO;
165 }
166
167 tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
168 tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
169 tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
170 tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
171 tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
172 tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
173 tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
174
175 return 0;
176}
177
178static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
179{
180 struct i2c_client *client = to_i2c_client(dev);
181 unsigned char buf[8];
182 int err, flags;
183
184 if (tm->tm_year < 100)
185 return -EINVAL;
186
187 buf[ABX8XX_REG_HTH] = 0;
188 buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
189 buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
190 buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
191 buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
192 buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
193 buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
194 buf[ABX8XX_REG_WD] = tm->tm_wday;
195
196 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
197 sizeof(buf), buf);
198 if (err < 0) {
199 dev_err(&client->dev, "Unable to write to date registers\n");
200 return -EIO;
201 }
202
203
204 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
205 if (flags < 0)
206 return flags;
207
208 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
209 flags & ~ABX8XX_OSS_OF);
210 if (err < 0) {
211 dev_err(&client->dev, "Unable to write oscillator status register\n");
212 return err;
213 }
214
215 return 0;
216}
217
218static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
219{
220 struct i2c_client *client = dev_id;
221 struct rtc_device *rtc = i2c_get_clientdata(client);
222 int status;
223
224 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
225 if (status < 0)
226 return IRQ_NONE;
227
228 if (status & ABX8XX_STATUS_AF)
229 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
230
231 i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
232
233 return IRQ_HANDLED;
234}
235
236static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
237{
238 struct i2c_client *client = to_i2c_client(dev);
239 unsigned char buf[7];
240
241 int irq_mask, err;
242
243 if (client->irq <= 0)
244 return -EINVAL;
245
246 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
247 sizeof(buf), buf);
248 if (err)
249 return err;
250
251 irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
252 if (irq_mask < 0)
253 return irq_mask;
254
255 t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
256 t->time.tm_min = bcd2bin(buf[1] & 0x7F);
257 t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
258 t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
259 t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
260 t->time.tm_wday = buf[5] & 0x7;
261
262 t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
263 t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
264
265 return err;
266}
267
268static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
269{
270 struct i2c_client *client = to_i2c_client(dev);
271 u8 alarm[6];
272 int err;
273
274 if (client->irq <= 0)
275 return -EINVAL;
276
277 alarm[0] = 0x0;
278 alarm[1] = bin2bcd(t->time.tm_sec);
279 alarm[2] = bin2bcd(t->time.tm_min);
280 alarm[3] = bin2bcd(t->time.tm_hour);
281 alarm[4] = bin2bcd(t->time.tm_mday);
282 alarm[5] = bin2bcd(t->time.tm_mon + 1);
283
284 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
285 sizeof(alarm), alarm);
286 if (err < 0) {
287 dev_err(&client->dev, "Unable to write alarm registers\n");
288 return -EIO;
289 }
290
291 if (t->enabled) {
292 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
293 (ABX8XX_IRQ_IM_1_4 |
294 ABX8XX_IRQ_AIE));
295 if (err)
296 return err;
297 }
298
299 return 0;
300}
301
302static int abx80x_rtc_set_autocalibration(struct device *dev,
303 int autocalibration)
304{
305 struct i2c_client *client = to_i2c_client(dev);
306 int retval, flags = 0;
307
308 if ((autocalibration != 0) && (autocalibration != 1024) &&
309 (autocalibration != 512)) {
310 dev_err(dev, "autocalibration value outside permitted range\n");
311 return -EINVAL;
312 }
313
314 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
315 if (flags < 0)
316 return flags;
317
318 if (autocalibration == 0) {
319 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
320 } else if (autocalibration == 1024) {
321
322 flags |= ABX8XX_OSC_ACAL_1024;
323 flags &= ~(ABX8XX_OSC_ACAL_512);
324 } else {
325
326 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
327 }
328
329
330 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
331 ABX8XX_CFG_KEY_OSC);
332 if (retval < 0) {
333 dev_err(dev, "Failed to write CONFIG_KEY register\n");
334 return retval;
335 }
336
337 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
338
339 return retval;
340}
341
342static int abx80x_rtc_get_autocalibration(struct device *dev)
343{
344 struct i2c_client *client = to_i2c_client(dev);
345 int flags = 0, autocalibration;
346
347 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
348 if (flags < 0)
349 return flags;
350
351 if (flags & ABX8XX_OSC_ACAL_512)
352 autocalibration = 512;
353 else if (flags & ABX8XX_OSC_ACAL_1024)
354 autocalibration = 1024;
355 else
356 autocalibration = 0;
357
358 return autocalibration;
359}
360
361static ssize_t autocalibration_store(struct device *dev,
362 struct device_attribute *attr,
363 const char *buf, size_t count)
364{
365 int retval;
366 unsigned long autocalibration = 0;
367
368 retval = kstrtoul(buf, 10, &autocalibration);
369 if (retval < 0) {
370 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
371 return -EINVAL;
372 }
373
374 retval = abx80x_rtc_set_autocalibration(dev, autocalibration);
375
376 return retval ? retval : count;
377}
378
379static ssize_t autocalibration_show(struct device *dev,
380 struct device_attribute *attr, char *buf)
381{
382 int autocalibration = 0;
383
384 autocalibration = abx80x_rtc_get_autocalibration(dev);
385 if (autocalibration < 0) {
386 dev_err(dev, "Failed to read RTC autocalibration\n");
387 sprintf(buf, "0\n");
388 return autocalibration;
389 }
390
391 return sprintf(buf, "%d\n", autocalibration);
392}
393
394static DEVICE_ATTR_RW(autocalibration);
395
396static ssize_t oscillator_store(struct device *dev,
397 struct device_attribute *attr,
398 const char *buf, size_t count)
399{
400 struct i2c_client *client = to_i2c_client(dev);
401 int retval, flags, rc_mode = 0;
402
403 if (strncmp(buf, "rc", 2) == 0) {
404 rc_mode = 1;
405 } else if (strncmp(buf, "xtal", 4) == 0) {
406 rc_mode = 0;
407 } else {
408 dev_err(dev, "Oscillator selection value outside permitted ones\n");
409 return -EINVAL;
410 }
411
412 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
413 if (flags < 0)
414 return flags;
415
416 if (rc_mode == 0)
417 flags &= ~(ABX8XX_OSC_OSEL);
418 else
419 flags |= (ABX8XX_OSC_OSEL);
420
421
422 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
423 ABX8XX_CFG_KEY_OSC);
424 if (retval < 0) {
425 dev_err(dev, "Failed to write CONFIG_KEY register\n");
426 return retval;
427 }
428
429 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
430 if (retval < 0) {
431 dev_err(dev, "Failed to write Oscillator Control register\n");
432 return retval;
433 }
434
435 return retval ? retval : count;
436}
437
438static ssize_t oscillator_show(struct device *dev,
439 struct device_attribute *attr, char *buf)
440{
441 int rc_mode = 0;
442 struct i2c_client *client = to_i2c_client(dev);
443
444 rc_mode = abx80x_is_rc_mode(client);
445
446 if (rc_mode < 0) {
447 dev_err(dev, "Failed to read RTC oscillator selection\n");
448 sprintf(buf, "\n");
449 return rc_mode;
450 }
451
452 if (rc_mode)
453 return sprintf(buf, "rc\n");
454 else
455 return sprintf(buf, "xtal\n");
456}
457
458static DEVICE_ATTR_RW(oscillator);
459
460static struct attribute *rtc_calib_attrs[] = {
461 &dev_attr_autocalibration.attr,
462 &dev_attr_oscillator.attr,
463 NULL,
464};
465
466static const struct attribute_group rtc_calib_attr_group = {
467 .attrs = rtc_calib_attrs,
468};
469
470static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
471{
472 struct i2c_client *client = to_i2c_client(dev);
473 int err;
474
475 if (enabled)
476 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
477 (ABX8XX_IRQ_IM_1_4 |
478 ABX8XX_IRQ_AIE));
479 else
480 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
481 ABX8XX_IRQ_IM_1_4);
482 return err;
483}
484
485static const struct rtc_class_ops abx80x_rtc_ops = {
486 .read_time = abx80x_rtc_read_time,
487 .set_time = abx80x_rtc_set_time,
488 .read_alarm = abx80x_read_alarm,
489 .set_alarm = abx80x_set_alarm,
490 .alarm_irq_enable = abx80x_alarm_irq_enable,
491};
492
493static int abx80x_dt_trickle_cfg(struct device_node *np)
494{
495 const char *diode;
496 int trickle_cfg = 0;
497 int i, ret;
498 u32 tmp;
499
500 ret = of_property_read_string(np, "abracon,tc-diode", &diode);
501 if (ret)
502 return ret;
503
504 if (!strcmp(diode, "standard"))
505 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
506 else if (!strcmp(diode, "schottky"))
507 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
508 else
509 return -EINVAL;
510
511 ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
512 if (ret)
513 return ret;
514
515 for (i = 0; i < sizeof(trickle_resistors); i++)
516 if (trickle_resistors[i] == tmp)
517 break;
518
519 if (i == sizeof(trickle_resistors))
520 return -EINVAL;
521
522 return (trickle_cfg | i);
523}
524
525static void rtc_calib_remove_sysfs_group(void *_dev)
526{
527 struct device *dev = _dev;
528
529 sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
530}
531
532static int abx80x_probe(struct i2c_client *client,
533 const struct i2c_device_id *id)
534{
535 struct device_node *np = client->dev.of_node;
536 struct rtc_device *rtc;
537 int i, data, err, trickle_cfg = -EINVAL;
538 char buf[7];
539 unsigned int part = id->driver_data;
540 unsigned int partnumber;
541 unsigned int majrev, minrev;
542 unsigned int lot;
543 unsigned int wafer;
544 unsigned int uid;
545
546 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
547 return -ENODEV;
548
549 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
550 sizeof(buf), buf);
551 if (err < 0) {
552 dev_err(&client->dev, "Unable to read partnumber\n");
553 return -EIO;
554 }
555
556 partnumber = (buf[0] << 8) | buf[1];
557 majrev = buf[2] >> 3;
558 minrev = buf[2] & 0x7;
559 lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
560 uid = ((buf[4] & 0x7f) << 8) | buf[5];
561 wafer = (buf[6] & 0x7c) >> 2;
562 dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
563 partnumber, majrev, minrev, lot, wafer, uid);
564
565 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
566 if (data < 0) {
567 dev_err(&client->dev, "Unable to read control register\n");
568 return -EIO;
569 }
570
571 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
572 ((data & ~(ABX8XX_CTRL_12_24 |
573 ABX8XX_CTRL_ARST)) |
574 ABX8XX_CTRL_WRITE));
575 if (err < 0) {
576 dev_err(&client->dev, "Unable to write control register\n");
577 return -EIO;
578 }
579
580
581 if (part == ABX80X) {
582 for (i = 0; abx80x_caps[i].pn; i++)
583 if (partnumber == abx80x_caps[i].pn)
584 break;
585 if (abx80x_caps[i].pn == 0) {
586 dev_err(&client->dev, "Unknown part: %04x\n",
587 partnumber);
588 return -EINVAL;
589 }
590 part = i;
591 }
592
593 if (partnumber != abx80x_caps[part].pn) {
594 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
595 partnumber, abx80x_caps[part].pn);
596 return -EINVAL;
597 }
598
599 if (np && abx80x_caps[part].has_tc)
600 trickle_cfg = abx80x_dt_trickle_cfg(np);
601
602 if (trickle_cfg > 0) {
603 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
604 trickle_cfg);
605 abx80x_enable_trickle_charger(client, trickle_cfg);
606 }
607
608 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
609 BIT(2));
610 if (err)
611 return err;
612
613 rtc = devm_rtc_allocate_device(&client->dev);
614 if (IS_ERR(rtc))
615 return PTR_ERR(rtc);
616
617 rtc->ops = &abx80x_rtc_ops;
618
619 i2c_set_clientdata(client, rtc);
620
621 if (client->irq > 0) {
622 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
623 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
624 abx80x_handle_irq,
625 IRQF_SHARED | IRQF_ONESHOT,
626 "abx8xx",
627 client);
628 if (err) {
629 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
630 client->irq = 0;
631 }
632 }
633
634
635 err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group);
636 if (err) {
637 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
638 err);
639 return err;
640 }
641
642 err = devm_add_action_or_reset(&client->dev,
643 rtc_calib_remove_sysfs_group,
644 &client->dev);
645 if (err) {
646 dev_err(&client->dev,
647 "Failed to add sysfs cleanup action: %d\n",
648 err);
649 return err;
650 }
651
652 err = rtc_register_device(rtc);
653
654 return err;
655}
656
657static int abx80x_remove(struct i2c_client *client)
658{
659 return 0;
660}
661
662static const struct i2c_device_id abx80x_id[] = {
663 { "abx80x", ABX80X },
664 { "ab0801", AB0801 },
665 { "ab0803", AB0803 },
666 { "ab0804", AB0804 },
667 { "ab0805", AB0805 },
668 { "ab1801", AB1801 },
669 { "ab1803", AB1803 },
670 { "ab1804", AB1804 },
671 { "ab1805", AB1805 },
672 { "rv1805", AB1805 },
673 { }
674};
675MODULE_DEVICE_TABLE(i2c, abx80x_id);
676
677static struct i2c_driver abx80x_driver = {
678 .driver = {
679 .name = "rtc-abx80x",
680 },
681 .probe = abx80x_probe,
682 .remove = abx80x_remove,
683 .id_table = abx80x_id,
684};
685
686module_i2c_driver(abx80x_driver);
687
688MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
689MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
690MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
691MODULE_LICENSE("GPL v2");
692
