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1/*
2 * A driver for the I2C members of the Abracon AB x8xx RTC family,
3 * and compatible: AB 1805 and AB 0805
4 *
5 * Copyright 2014-2015 Macq S.A.
6 *
7 * Author: Philippe De Muyter <phdm@macqel.be>
8 * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
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 * Write the configuration key register to enable access to the Trickle
118 * register
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 /* Read the Oscillator Failure only in XT mode */
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 err = rtc_valid_tm(tm);
176 if (err < 0)
177 dev_err(&client->dev, "retrieved date/time is not valid.\n");
178
179 return err;
180}
181
182static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
183{
184 struct i2c_client *client = to_i2c_client(dev);
185 unsigned char buf[8];
186 int err, flags;
187
188 if (tm->tm_year < 100)
189 return -EINVAL;
190
191 buf[ABX8XX_REG_HTH] = 0;
192 buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
193 buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
194 buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
195 buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
196 buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
197 buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
198 buf[ABX8XX_REG_WD] = tm->tm_wday;
199
200 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
201 sizeof(buf), buf);
202 if (err < 0) {
203 dev_err(&client->dev, "Unable to write to date registers\n");
204 return -EIO;
205 }
206
207 /* Clear the OF bit of Oscillator Status Register */
208 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
209 if (flags < 0)
210 return flags;
211
212 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
213 flags & ~ABX8XX_OSS_OF);
214 if (err < 0) {
215 dev_err(&client->dev, "Unable to write oscillator status register\n");
216 return err;
217 }
218
219 return 0;
220}
221
222static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
223{
224 struct i2c_client *client = dev_id;
225 struct rtc_device *rtc = i2c_get_clientdata(client);
226 int status;
227
228 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
229 if (status < 0)
230 return IRQ_NONE;
231
232 if (status & ABX8XX_STATUS_AF)
233 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
234
235 i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
236
237 return IRQ_HANDLED;
238}
239
240static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
241{
242 struct i2c_client *client = to_i2c_client(dev);
243 unsigned char buf[7];
244
245 int irq_mask, err;
246
247 if (client->irq <= 0)
248 return -EINVAL;
249
250 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
251 sizeof(buf), buf);
252 if (err)
253 return err;
254
255 irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
256 if (irq_mask < 0)
257 return irq_mask;
258
259 t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
260 t->time.tm_min = bcd2bin(buf[1] & 0x7F);
261 t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
262 t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
263 t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
264 t->time.tm_wday = buf[5] & 0x7;
265
266 t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
267 t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
268
269 return err;
270}
271
272static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
273{
274 struct i2c_client *client = to_i2c_client(dev);
275 u8 alarm[6];
276 int err;
277
278 if (client->irq <= 0)
279 return -EINVAL;
280
281 alarm[0] = 0x0;
282 alarm[1] = bin2bcd(t->time.tm_sec);
283 alarm[2] = bin2bcd(t->time.tm_min);
284 alarm[3] = bin2bcd(t->time.tm_hour);
285 alarm[4] = bin2bcd(t->time.tm_mday);
286 alarm[5] = bin2bcd(t->time.tm_mon + 1);
287
288 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
289 sizeof(alarm), alarm);
290 if (err < 0) {
291 dev_err(&client->dev, "Unable to write alarm registers\n");
292 return -EIO;
293 }
294
295 if (t->enabled) {
296 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
297 (ABX8XX_IRQ_IM_1_4 |
298 ABX8XX_IRQ_AIE));
299 if (err)
300 return err;
301 }
302
303 return 0;
304}
305
306static int abx80x_rtc_set_autocalibration(struct device *dev,
307 int autocalibration)
308{
309 struct i2c_client *client = to_i2c_client(dev);
310 int retval, flags = 0;
311
312 if ((autocalibration != 0) && (autocalibration != 1024) &&
313 (autocalibration != 512)) {
314 dev_err(dev, "autocalibration value outside permitted range\n");
315 return -EINVAL;
316 }
317
318 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
319 if (flags < 0)
320 return flags;
321
322 if (autocalibration == 0) {
323 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
324 } else if (autocalibration == 1024) {
325 /* 1024 autocalibration is 0x10 */
326 flags |= ABX8XX_OSC_ACAL_1024;
327 flags &= ~(ABX8XX_OSC_ACAL_512);
328 } else {
329 /* 512 autocalibration is 0x11 */
330 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
331 }
332
333 /* Unlock write access to Oscillator Control Register */
334 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
335 ABX8XX_CFG_KEY_OSC);
336 if (retval < 0) {
337 dev_err(dev, "Failed to write CONFIG_KEY register\n");
338 return retval;
339 }
340
341 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
342
343 return retval;
344}
345
346static int abx80x_rtc_get_autocalibration(struct device *dev)
347{
348 struct i2c_client *client = to_i2c_client(dev);
349 int flags = 0, autocalibration;
350
351 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
352 if (flags < 0)
353 return flags;
354
355 if (flags & ABX8XX_OSC_ACAL_512)
356 autocalibration = 512;
357 else if (flags & ABX8XX_OSC_ACAL_1024)
358 autocalibration = 1024;
359 else
360 autocalibration = 0;
361
362 return autocalibration;
363}
364
365static ssize_t autocalibration_store(struct device *dev,
366 struct device_attribute *attr,
367 const char *buf, size_t count)
368{
369 int retval;
370 unsigned long autocalibration = 0;
371
372 retval = kstrtoul(buf, 10, &autocalibration);
373 if (retval < 0) {
374 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
375 return -EINVAL;
376 }
377
378 retval = abx80x_rtc_set_autocalibration(dev, autocalibration);
379
380 return retval ? retval : count;
381}
382
383static ssize_t autocalibration_show(struct device *dev,
384 struct device_attribute *attr, char *buf)
385{
386 int autocalibration = 0;
387
388 autocalibration = abx80x_rtc_get_autocalibration(dev);
389 if (autocalibration < 0) {
390 dev_err(dev, "Failed to read RTC autocalibration\n");
391 sprintf(buf, "0\n");
392 return autocalibration;
393 }
394
395 return sprintf(buf, "%d\n", autocalibration);
396}
397
398static DEVICE_ATTR_RW(autocalibration);
399
400static ssize_t oscillator_store(struct device *dev,
401 struct device_attribute *attr,
402 const char *buf, size_t count)
403{
404 struct i2c_client *client = to_i2c_client(dev);
405 int retval, flags, rc_mode = 0;
406
407 if (strncmp(buf, "rc", 2) == 0) {
408 rc_mode = 1;
409 } else if (strncmp(buf, "xtal", 4) == 0) {
410 rc_mode = 0;
411 } else {
412 dev_err(dev, "Oscillator selection value outside permitted ones\n");
413 return -EINVAL;
414 }
415
416 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
417 if (flags < 0)
418 return flags;
419
420 if (rc_mode == 0)
421 flags &= ~(ABX8XX_OSC_OSEL);
422 else
423 flags |= (ABX8XX_OSC_OSEL);
424
425 /* Unlock write access on Oscillator Control register */
426 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
427 ABX8XX_CFG_KEY_OSC);
428 if (retval < 0) {
429 dev_err(dev, "Failed to write CONFIG_KEY register\n");
430 return retval;
431 }
432
433 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
434 if (retval < 0) {
435 dev_err(dev, "Failed to write Oscillator Control register\n");
436 return retval;
437 }
438
439 return retval ? retval : count;
440}
441
442static ssize_t oscillator_show(struct device *dev,
443 struct device_attribute *attr, char *buf)
444{
445 int rc_mode = 0;
446 struct i2c_client *client = to_i2c_client(dev);
447
448 rc_mode = abx80x_is_rc_mode(client);
449
450 if (rc_mode < 0) {
451 dev_err(dev, "Failed to read RTC oscillator selection\n");
452 sprintf(buf, "\n");
453 return rc_mode;
454 }
455
456 if (rc_mode)
457 return sprintf(buf, "rc\n");
458 else
459 return sprintf(buf, "xtal\n");
460}
461
462static DEVICE_ATTR_RW(oscillator);
463
464static struct attribute *rtc_calib_attrs[] = {
465 &dev_attr_autocalibration.attr,
466 &dev_attr_oscillator.attr,
467 NULL,
468};
469
470static const struct attribute_group rtc_calib_attr_group = {
471 .attrs = rtc_calib_attrs,
472};
473
474static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
475{
476 struct i2c_client *client = to_i2c_client(dev);
477 int err;
478
479 if (enabled)
480 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
481 (ABX8XX_IRQ_IM_1_4 |
482 ABX8XX_IRQ_AIE));
483 else
484 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
485 ABX8XX_IRQ_IM_1_4);
486 return err;
487}
488
489static const struct rtc_class_ops abx80x_rtc_ops = {
490 .read_time = abx80x_rtc_read_time,
491 .set_time = abx80x_rtc_set_time,
492 .read_alarm = abx80x_read_alarm,
493 .set_alarm = abx80x_set_alarm,
494 .alarm_irq_enable = abx80x_alarm_irq_enable,
495};
496
497static int abx80x_dt_trickle_cfg(struct device_node *np)
498{
499 const char *diode;
500 int trickle_cfg = 0;
501 int i, ret;
502 u32 tmp;
503
504 ret = of_property_read_string(np, "abracon,tc-diode", &diode);
505 if (ret)
506 return ret;
507
508 if (!strcmp(diode, "standard"))
509 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
510 else if (!strcmp(diode, "schottky"))
511 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
512 else
513 return -EINVAL;
514
515 ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
516 if (ret)
517 return ret;
518
519 for (i = 0; i < sizeof(trickle_resistors); i++)
520 if (trickle_resistors[i] == tmp)
521 break;
522
523 if (i == sizeof(trickle_resistors))
524 return -EINVAL;
525
526 return (trickle_cfg | i);
527}
528
529static void rtc_calib_remove_sysfs_group(void *_dev)
530{
531 struct device *dev = _dev;
532
533 sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
534}
535
536static int abx80x_probe(struct i2c_client *client,
537 const struct i2c_device_id *id)
538{
539 struct device_node *np = client->dev.of_node;
540 struct rtc_device *rtc;
541 int i, data, err, trickle_cfg = -EINVAL;
542 char buf[7];
543 unsigned int part = id->driver_data;
544 unsigned int partnumber;
545 unsigned int majrev, minrev;
546 unsigned int lot;
547 unsigned int wafer;
548 unsigned int uid;
549
550 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
551 return -ENODEV;
552
553 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
554 sizeof(buf), buf);
555 if (err < 0) {
556 dev_err(&client->dev, "Unable to read partnumber\n");
557 return -EIO;
558 }
559
560 partnumber = (buf[0] << 8) | buf[1];
561 majrev = buf[2] >> 3;
562 minrev = buf[2] & 0x7;
563 lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
564 uid = ((buf[4] & 0x7f) << 8) | buf[5];
565 wafer = (buf[6] & 0x7c) >> 2;
566 dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
567 partnumber, majrev, minrev, lot, wafer, uid);
568
569 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
570 if (data < 0) {
571 dev_err(&client->dev, "Unable to read control register\n");
572 return -EIO;
573 }
574
575 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
576 ((data & ~(ABX8XX_CTRL_12_24 |
577 ABX8XX_CTRL_ARST)) |
578 ABX8XX_CTRL_WRITE));
579 if (err < 0) {
580 dev_err(&client->dev, "Unable to write control register\n");
581 return -EIO;
582 }
583
584 /* part autodetection */
585 if (part == ABX80X) {
586 for (i = 0; abx80x_caps[i].pn; i++)
587 if (partnumber == abx80x_caps[i].pn)
588 break;
589 if (abx80x_caps[i].pn == 0) {
590 dev_err(&client->dev, "Unknown part: %04x\n",
591 partnumber);
592 return -EINVAL;
593 }
594 part = i;
595 }
596
597 if (partnumber != abx80x_caps[part].pn) {
598 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
599 partnumber, abx80x_caps[part].pn);
600 return -EINVAL;
601 }
602
603 if (np && abx80x_caps[part].has_tc)
604 trickle_cfg = abx80x_dt_trickle_cfg(np);
605
606 if (trickle_cfg > 0) {
607 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
608 trickle_cfg);
609 abx80x_enable_trickle_charger(client, trickle_cfg);
610 }
611
612 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
613 BIT(2));
614 if (err)
615 return err;
616
617 rtc = devm_rtc_device_register(&client->dev, "abx8xx",
618 &abx80x_rtc_ops, THIS_MODULE);
619
620 if (IS_ERR(rtc))
621 return PTR_ERR(rtc);
622
623 i2c_set_clientdata(client, rtc);
624
625 if (client->irq > 0) {
626 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
627 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
628 abx80x_handle_irq,
629 IRQF_SHARED | IRQF_ONESHOT,
630 "abx8xx",
631 client);
632 if (err) {
633 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
634 client->irq = 0;
635 }
636 }
637
638 /* Export sysfs entries */
639 err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group);
640 if (err) {
641 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
642 err);
643 return err;
644 }
645
646 err = devm_add_action(&client->dev, rtc_calib_remove_sysfs_group,
647 &client->dev);
648 if (err) {
649 rtc_calib_remove_sysfs_group(&client->dev);
650 dev_err(&client->dev,
651 "Failed to add sysfs cleanup action: %d\n",
652 err);
653 return err;
654 }
655
656 return 0;
657}
658
659static int abx80x_remove(struct i2c_client *client)
660{
661 return 0;
662}
663
664static const struct i2c_device_id abx80x_id[] = {
665 { "abx80x", ABX80X },
666 { "ab0801", AB0801 },
667 { "ab0803", AB0803 },
668 { "ab0804", AB0804 },
669 { "ab0805", AB0805 },
670 { "ab1801", AB1801 },
671 { "ab1803", AB1803 },
672 { "ab1804", AB1804 },
673 { "ab1805", AB1805 },
674 { "rv1805", AB1805 },
675 { }
676};
677MODULE_DEVICE_TABLE(i2c, abx80x_id);
678
679static struct i2c_driver abx80x_driver = {
680 .driver = {
681 .name = "rtc-abx80x",
682 },
683 .probe = abx80x_probe,
684 .remove = abx80x_remove,
685 .id_table = abx80x_id,
686};
687
688module_i2c_driver(abx80x_driver);
689
690MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
691MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
692MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
693MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * A driver for the I2C members of the Abracon AB x8xx RTC family,
4 * and compatible: AB 1805 and AB 0805
5 *
6 * Copyright 2014-2015 Macq S.A.
7 *
8 * Author: Philippe De Muyter <phdm@macqel.be>
9 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
10 *
11 */
12
13#include <linux/bcd.h>
14#include <linux/bitfield.h>
15#include <linux/i2c.h>
16#include <linux/kstrtox.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/rtc.h>
20#include <linux/watchdog.h>
21
22#define ABX8XX_REG_HTH 0x00
23#define ABX8XX_REG_SC 0x01
24#define ABX8XX_REG_MN 0x02
25#define ABX8XX_REG_HR 0x03
26#define ABX8XX_REG_DA 0x04
27#define ABX8XX_REG_MO 0x05
28#define ABX8XX_REG_YR 0x06
29#define ABX8XX_REG_WD 0x07
30
31#define ABX8XX_REG_AHTH 0x08
32#define ABX8XX_REG_ASC 0x09
33#define ABX8XX_REG_AMN 0x0a
34#define ABX8XX_REG_AHR 0x0b
35#define ABX8XX_REG_ADA 0x0c
36#define ABX8XX_REG_AMO 0x0d
37#define ABX8XX_REG_AWD 0x0e
38
39#define ABX8XX_REG_STATUS 0x0f
40#define ABX8XX_STATUS_AF BIT(2)
41#define ABX8XX_STATUS_BLF BIT(4)
42#define ABX8XX_STATUS_WDT BIT(5)
43
44#define ABX8XX_REG_CTRL1 0x10
45#define ABX8XX_CTRL_WRITE BIT(0)
46#define ABX8XX_CTRL_ARST BIT(2)
47#define ABX8XX_CTRL_12_24 BIT(6)
48
49#define ABX8XX_REG_CTRL2 0x11
50#define ABX8XX_CTRL2_RSVD BIT(5)
51
52#define ABX8XX_REG_IRQ 0x12
53#define ABX8XX_IRQ_AIE BIT(2)
54#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
55
56#define ABX8XX_REG_CD_TIMER_CTL 0x18
57
58#define ABX8XX_REG_OSC 0x1c
59#define ABX8XX_OSC_FOS BIT(3)
60#define ABX8XX_OSC_BOS BIT(4)
61#define ABX8XX_OSC_ACAL_512 BIT(5)
62#define ABX8XX_OSC_ACAL_1024 BIT(6)
63
64#define ABX8XX_OSC_OSEL BIT(7)
65
66#define ABX8XX_REG_OSS 0x1d
67#define ABX8XX_OSS_OF BIT(1)
68#define ABX8XX_OSS_OMODE BIT(4)
69
70#define ABX8XX_REG_WDT 0x1b
71#define ABX8XX_WDT_WDS BIT(7)
72#define ABX8XX_WDT_BMB_MASK 0x7c
73#define ABX8XX_WDT_BMB_SHIFT 2
74#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
75#define ABX8XX_WDT_WRB_MASK 0x03
76#define ABX8XX_WDT_WRB_1HZ 0x02
77
78#define ABX8XX_REG_CFG_KEY 0x1f
79#define ABX8XX_CFG_KEY_OSC 0xa1
80#define ABX8XX_CFG_KEY_MISC 0x9d
81
82#define ABX8XX_REG_ID0 0x28
83
84#define ABX8XX_REG_OUT_CTRL 0x30
85#define ABX8XX_OUT_CTRL_EXDS BIT(4)
86
87#define ABX8XX_REG_TRICKLE 0x20
88#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
89#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
90#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
91
92#define ABX8XX_REG_EXTRAM 0x3f
93#define ABX8XX_EXTRAM_XADS GENMASK(1, 0)
94
95#define ABX8XX_SRAM_BASE 0x40
96#define ABX8XX_SRAM_WIN_SIZE 0x40
97#define ABX8XX_RAM_SIZE 256
98
99#define NVMEM_ADDR_LOWER GENMASK(5, 0)
100#define NVMEM_ADDR_UPPER GENMASK(7, 6)
101
102static u8 trickle_resistors[] = {0, 3, 6, 11};
103
104enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
105 AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
106
107struct abx80x_cap {
108 u16 pn;
109 bool has_tc;
110 bool has_wdog;
111};
112
113static struct abx80x_cap abx80x_caps[] = {
114 [AB0801] = {.pn = 0x0801},
115 [AB0803] = {.pn = 0x0803},
116 [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
117 [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
118 [AB1801] = {.pn = 0x1801},
119 [AB1803] = {.pn = 0x1803},
120 [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
121 [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
122 [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
123 [ABX80X] = {.pn = 0}
124};
125
126struct abx80x_priv {
127 struct rtc_device *rtc;
128 struct i2c_client *client;
129 struct watchdog_device wdog;
130};
131
132static int abx80x_write_config_key(struct i2c_client *client, u8 key)
133{
134 if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
135 dev_err(&client->dev, "Unable to write configuration key\n");
136 return -EIO;
137 }
138
139 return 0;
140}
141
142static int abx80x_is_rc_mode(struct i2c_client *client)
143{
144 int flags = 0;
145
146 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
147 if (flags < 0) {
148 dev_err(&client->dev,
149 "Failed to read autocalibration attribute\n");
150 return flags;
151 }
152
153 return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
154}
155
156static int abx80x_enable_trickle_charger(struct i2c_client *client,
157 u8 trickle_cfg)
158{
159 int err;
160
161 /*
162 * Write the configuration key register to enable access to the Trickle
163 * register
164 */
165 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
166 return -EIO;
167
168 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
169 ABX8XX_TRICKLE_CHARGE_ENABLE |
170 trickle_cfg);
171 if (err < 0) {
172 dev_err(&client->dev, "Unable to write trickle register\n");
173 return -EIO;
174 }
175
176 return 0;
177}
178
179static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
180{
181 struct i2c_client *client = to_i2c_client(dev);
182 unsigned char buf[8];
183 int err, flags, rc_mode = 0;
184
185 /* Read the Oscillator Failure only in XT mode */
186 rc_mode = abx80x_is_rc_mode(client);
187 if (rc_mode < 0)
188 return rc_mode;
189
190 if (!rc_mode) {
191 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
192 if (flags < 0)
193 return flags;
194
195 if (flags & ABX8XX_OSS_OF) {
196 dev_err(dev, "Oscillator failure, data is invalid.\n");
197 return -EINVAL;
198 }
199 }
200
201 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
202 sizeof(buf), buf);
203 if (err < 0) {
204 dev_err(&client->dev, "Unable to read date\n");
205 return -EIO;
206 }
207
208 tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
209 tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
210 tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
211 tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
212 tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
213 tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
214 tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
215
216 return 0;
217}
218
219static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
220{
221 struct i2c_client *client = to_i2c_client(dev);
222 unsigned char buf[8];
223 int err, flags;
224
225 if (tm->tm_year < 100)
226 return -EINVAL;
227
228 buf[ABX8XX_REG_HTH] = 0;
229 buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
230 buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
231 buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
232 buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
233 buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
234 buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
235 buf[ABX8XX_REG_WD] = tm->tm_wday;
236
237 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
238 sizeof(buf), buf);
239 if (err < 0) {
240 dev_err(&client->dev, "Unable to write to date registers\n");
241 return -EIO;
242 }
243
244 /* Clear the OF bit of Oscillator Status Register */
245 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
246 if (flags < 0)
247 return flags;
248
249 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
250 flags & ~ABX8XX_OSS_OF);
251 if (err < 0) {
252 dev_err(&client->dev, "Unable to write oscillator status register\n");
253 return err;
254 }
255
256 return 0;
257}
258
259static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
260{
261 struct i2c_client *client = dev_id;
262 struct abx80x_priv *priv = i2c_get_clientdata(client);
263 struct rtc_device *rtc = priv->rtc;
264 int status;
265
266 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
267 if (status < 0)
268 return IRQ_NONE;
269
270 if (status & ABX8XX_STATUS_AF)
271 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
272
273 /*
274 * It is unclear if we'll get an interrupt before the external
275 * reset kicks in.
276 */
277 if (status & ABX8XX_STATUS_WDT)
278 dev_alert(&client->dev, "watchdog timeout interrupt.\n");
279
280 i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
281
282 return IRQ_HANDLED;
283}
284
285static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
286{
287 struct i2c_client *client = to_i2c_client(dev);
288 unsigned char buf[7];
289
290 int irq_mask, err;
291
292 if (client->irq <= 0)
293 return -EINVAL;
294
295 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
296 sizeof(buf), buf);
297 if (err)
298 return err;
299
300 irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
301 if (irq_mask < 0)
302 return irq_mask;
303
304 t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
305 t->time.tm_min = bcd2bin(buf[1] & 0x7F);
306 t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
307 t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
308 t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
309 t->time.tm_wday = buf[5] & 0x7;
310
311 t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
312 t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
313
314 return err;
315}
316
317static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
318{
319 struct i2c_client *client = to_i2c_client(dev);
320 u8 alarm[6];
321 int err;
322
323 if (client->irq <= 0)
324 return -EINVAL;
325
326 alarm[0] = 0x0;
327 alarm[1] = bin2bcd(t->time.tm_sec);
328 alarm[2] = bin2bcd(t->time.tm_min);
329 alarm[3] = bin2bcd(t->time.tm_hour);
330 alarm[4] = bin2bcd(t->time.tm_mday);
331 alarm[5] = bin2bcd(t->time.tm_mon + 1);
332
333 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
334 sizeof(alarm), alarm);
335 if (err < 0) {
336 dev_err(&client->dev, "Unable to write alarm registers\n");
337 return -EIO;
338 }
339
340 if (t->enabled) {
341 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
342 (ABX8XX_IRQ_IM_1_4 |
343 ABX8XX_IRQ_AIE));
344 if (err)
345 return err;
346 }
347
348 return 0;
349}
350
351static int abx80x_rtc_set_autocalibration(struct device *dev,
352 int autocalibration)
353{
354 struct i2c_client *client = to_i2c_client(dev);
355 int retval, flags = 0;
356
357 if ((autocalibration != 0) && (autocalibration != 1024) &&
358 (autocalibration != 512)) {
359 dev_err(dev, "autocalibration value outside permitted range\n");
360 return -EINVAL;
361 }
362
363 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
364 if (flags < 0)
365 return flags;
366
367 if (autocalibration == 0) {
368 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
369 } else if (autocalibration == 1024) {
370 /* 1024 autocalibration is 0x10 */
371 flags |= ABX8XX_OSC_ACAL_1024;
372 flags &= ~(ABX8XX_OSC_ACAL_512);
373 } else {
374 /* 512 autocalibration is 0x11 */
375 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
376 }
377
378 /* Unlock write access to Oscillator Control Register */
379 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
380 return -EIO;
381
382 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
383
384 return retval;
385}
386
387static int abx80x_rtc_get_autocalibration(struct device *dev)
388{
389 struct i2c_client *client = to_i2c_client(dev);
390 int flags = 0, autocalibration;
391
392 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
393 if (flags < 0)
394 return flags;
395
396 if (flags & ABX8XX_OSC_ACAL_512)
397 autocalibration = 512;
398 else if (flags & ABX8XX_OSC_ACAL_1024)
399 autocalibration = 1024;
400 else
401 autocalibration = 0;
402
403 return autocalibration;
404}
405
406static ssize_t autocalibration_store(struct device *dev,
407 struct device_attribute *attr,
408 const char *buf, size_t count)
409{
410 int retval;
411 unsigned long autocalibration = 0;
412
413 retval = kstrtoul(buf, 10, &autocalibration);
414 if (retval < 0) {
415 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
416 return -EINVAL;
417 }
418
419 retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
420
421 return retval ? retval : count;
422}
423
424static ssize_t autocalibration_show(struct device *dev,
425 struct device_attribute *attr, char *buf)
426{
427 int autocalibration = 0;
428
429 autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
430 if (autocalibration < 0) {
431 dev_err(dev, "Failed to read RTC autocalibration\n");
432 sprintf(buf, "0\n");
433 return autocalibration;
434 }
435
436 return sprintf(buf, "%d\n", autocalibration);
437}
438
439static DEVICE_ATTR_RW(autocalibration);
440
441static ssize_t oscillator_store(struct device *dev,
442 struct device_attribute *attr,
443 const char *buf, size_t count)
444{
445 struct i2c_client *client = to_i2c_client(dev->parent);
446 int retval, flags, rc_mode = 0;
447
448 if (strncmp(buf, "rc", 2) == 0) {
449 rc_mode = 1;
450 } else if (strncmp(buf, "xtal", 4) == 0) {
451 rc_mode = 0;
452 } else {
453 dev_err(dev, "Oscillator selection value outside permitted ones\n");
454 return -EINVAL;
455 }
456
457 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
458 if (flags < 0)
459 return flags;
460
461 if (rc_mode == 0)
462 flags &= ~(ABX8XX_OSC_OSEL);
463 else
464 flags |= (ABX8XX_OSC_OSEL);
465
466 /* Unlock write access on Oscillator Control register */
467 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
468 return -EIO;
469
470 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
471 if (retval < 0) {
472 dev_err(dev, "Failed to write Oscillator Control register\n");
473 return retval;
474 }
475
476 return retval ? retval : count;
477}
478
479static ssize_t oscillator_show(struct device *dev,
480 struct device_attribute *attr, char *buf)
481{
482 int rc_mode = 0;
483 struct i2c_client *client = to_i2c_client(dev->parent);
484
485 rc_mode = abx80x_is_rc_mode(client);
486
487 if (rc_mode < 0) {
488 dev_err(dev, "Failed to read RTC oscillator selection\n");
489 sprintf(buf, "\n");
490 return rc_mode;
491 }
492
493 if (rc_mode)
494 return sprintf(buf, "rc\n");
495 else
496 return sprintf(buf, "xtal\n");
497}
498
499static DEVICE_ATTR_RW(oscillator);
500
501static struct attribute *rtc_calib_attrs[] = {
502 &dev_attr_autocalibration.attr,
503 &dev_attr_oscillator.attr,
504 NULL,
505};
506
507static const struct attribute_group rtc_calib_attr_group = {
508 .attrs = rtc_calib_attrs,
509};
510
511static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
512{
513 struct i2c_client *client = to_i2c_client(dev);
514 int err;
515
516 if (enabled)
517 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
518 (ABX8XX_IRQ_IM_1_4 |
519 ABX8XX_IRQ_AIE));
520 else
521 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
522 ABX8XX_IRQ_IM_1_4);
523 return err;
524}
525
526static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
527{
528 struct i2c_client *client = to_i2c_client(dev);
529 int status, tmp;
530
531 switch (cmd) {
532 case RTC_VL_READ:
533 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
534 if (status < 0)
535 return status;
536
537 tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
538
539 return put_user(tmp, (unsigned int __user *)arg);
540
541 case RTC_VL_CLR:
542 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
543 if (status < 0)
544 return status;
545
546 status &= ~ABX8XX_STATUS_BLF;
547
548 tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
549 if (tmp < 0)
550 return tmp;
551
552 return 0;
553
554 default:
555 return -ENOIOCTLCMD;
556 }
557}
558
559static const struct rtc_class_ops abx80x_rtc_ops = {
560 .read_time = abx80x_rtc_read_time,
561 .set_time = abx80x_rtc_set_time,
562 .read_alarm = abx80x_read_alarm,
563 .set_alarm = abx80x_set_alarm,
564 .alarm_irq_enable = abx80x_alarm_irq_enable,
565 .ioctl = abx80x_ioctl,
566};
567
568static int abx80x_dt_trickle_cfg(struct i2c_client *client)
569{
570 struct device_node *np = client->dev.of_node;
571 const char *diode;
572 int trickle_cfg = 0;
573 int i, ret;
574 u32 tmp;
575
576 ret = of_property_read_string(np, "abracon,tc-diode", &diode);
577 if (ret)
578 return ret;
579
580 if (!strcmp(diode, "standard")) {
581 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
582 } else if (!strcmp(diode, "schottky")) {
583 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
584 } else {
585 dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
586 return -EINVAL;
587 }
588
589 ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
590 if (ret)
591 return ret;
592
593 for (i = 0; i < sizeof(trickle_resistors); i++)
594 if (trickle_resistors[i] == tmp)
595 break;
596
597 if (i == sizeof(trickle_resistors)) {
598 dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
599 return -EINVAL;
600 }
601
602 return (trickle_cfg | i);
603}
604
605#ifdef CONFIG_WATCHDOG
606
607static inline u8 timeout_bits(unsigned int timeout)
608{
609 return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
610 ABX8XX_WDT_WRB_1HZ;
611}
612
613static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
614 unsigned int timeout)
615{
616 struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
617 u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
618
619 /*
620 * Writing any timeout to the WDT register resets the watchdog timer.
621 * Writing 0 disables it.
622 */
623 return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
624}
625
626static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
627 unsigned int new_timeout)
628{
629 int err = 0;
630
631 if (watchdog_hw_running(wdog))
632 err = __abx80x_wdog_set_timeout(wdog, new_timeout);
633
634 if (err == 0)
635 wdog->timeout = new_timeout;
636
637 return err;
638}
639
640static int abx80x_wdog_ping(struct watchdog_device *wdog)
641{
642 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
643}
644
645static int abx80x_wdog_start(struct watchdog_device *wdog)
646{
647 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
648}
649
650static int abx80x_wdog_stop(struct watchdog_device *wdog)
651{
652 return __abx80x_wdog_set_timeout(wdog, 0);
653}
654
655static const struct watchdog_info abx80x_wdog_info = {
656 .identity = "abx80x watchdog",
657 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
658};
659
660static const struct watchdog_ops abx80x_wdog_ops = {
661 .owner = THIS_MODULE,
662 .start = abx80x_wdog_start,
663 .stop = abx80x_wdog_stop,
664 .ping = abx80x_wdog_ping,
665 .set_timeout = abx80x_wdog_set_timeout,
666};
667
668static int abx80x_setup_watchdog(struct abx80x_priv *priv)
669{
670 priv->wdog.parent = &priv->client->dev;
671 priv->wdog.ops = &abx80x_wdog_ops;
672 priv->wdog.info = &abx80x_wdog_info;
673 priv->wdog.min_timeout = 1;
674 priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
675 priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
676
677 watchdog_set_drvdata(&priv->wdog, priv);
678
679 return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
680}
681#else
682static int abx80x_setup_watchdog(struct abx80x_priv *priv)
683{
684 return 0;
685}
686#endif
687
688static int abx80x_nvmem_xfer(struct abx80x_priv *priv, unsigned int offset,
689 void *val, size_t bytes, bool write)
690{
691 int ret;
692
693 while (bytes) {
694 u8 extram, reg, len, lower, upper;
695
696 lower = FIELD_GET(NVMEM_ADDR_LOWER, offset);
697 upper = FIELD_GET(NVMEM_ADDR_UPPER, offset);
698 extram = FIELD_PREP(ABX8XX_EXTRAM_XADS, upper);
699 reg = ABX8XX_SRAM_BASE + lower;
700 len = min(lower + bytes, (size_t)ABX8XX_SRAM_WIN_SIZE) - lower;
701 len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
702
703 ret = i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_EXTRAM,
704 extram);
705 if (ret)
706 return ret;
707
708 if (write) {
709 ret = i2c_smbus_write_i2c_block_data(priv->client, reg,
710 len, val);
711 if (ret)
712 return ret;
713 } else {
714 ret = i2c_smbus_read_i2c_block_data(priv->client, reg,
715 len, val);
716 if (ret <= 0)
717 return ret ? ret : -EIO;
718 len = ret;
719 }
720
721 offset += len;
722 val += len;
723 bytes -= len;
724 }
725
726 return 0;
727}
728
729static int abx80x_nvmem_read(void *priv, unsigned int offset, void *val,
730 size_t bytes)
731{
732 return abx80x_nvmem_xfer(priv, offset, val, bytes, false);
733}
734
735static int abx80x_nvmem_write(void *priv, unsigned int offset, void *val,
736 size_t bytes)
737{
738 return abx80x_nvmem_xfer(priv, offset, val, bytes, true);
739}
740
741static int abx80x_setup_nvmem(struct abx80x_priv *priv)
742{
743 struct nvmem_config config = {
744 .type = NVMEM_TYPE_BATTERY_BACKED,
745 .reg_read = abx80x_nvmem_read,
746 .reg_write = abx80x_nvmem_write,
747 .size = ABX8XX_RAM_SIZE,
748 .priv = priv,
749 };
750
751 return devm_rtc_nvmem_register(priv->rtc, &config);
752}
753
754static const struct i2c_device_id abx80x_id[] = {
755 { "abx80x", ABX80X },
756 { "ab0801", AB0801 },
757 { "ab0803", AB0803 },
758 { "ab0804", AB0804 },
759 { "ab0805", AB0805 },
760 { "ab1801", AB1801 },
761 { "ab1803", AB1803 },
762 { "ab1804", AB1804 },
763 { "ab1805", AB1805 },
764 { "rv1805", RV1805 },
765 { }
766};
767MODULE_DEVICE_TABLE(i2c, abx80x_id);
768
769static int abx80x_probe(struct i2c_client *client)
770{
771 struct device_node *np = client->dev.of_node;
772 struct abx80x_priv *priv;
773 int i, data, err, trickle_cfg = -EINVAL;
774 char buf[7];
775 const struct i2c_device_id *id = i2c_match_id(abx80x_id, client);
776 unsigned int part = id->driver_data;
777 unsigned int partnumber;
778 unsigned int majrev, minrev;
779 unsigned int lot;
780 unsigned int wafer;
781 unsigned int uid;
782
783 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
784 return -ENODEV;
785
786 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
787 sizeof(buf), buf);
788 if (err < 0) {
789 dev_err(&client->dev, "Unable to read partnumber\n");
790 return -EIO;
791 }
792
793 partnumber = (buf[0] << 8) | buf[1];
794 majrev = buf[2] >> 3;
795 minrev = buf[2] & 0x7;
796 lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
797 uid = ((buf[4] & 0x7f) << 8) | buf[5];
798 wafer = (buf[6] & 0x7c) >> 2;
799 dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
800 partnumber, majrev, minrev, lot, wafer, uid);
801
802 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
803 if (data < 0) {
804 dev_err(&client->dev, "Unable to read control register\n");
805 return -EIO;
806 }
807
808 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
809 ((data & ~(ABX8XX_CTRL_12_24 |
810 ABX8XX_CTRL_ARST)) |
811 ABX8XX_CTRL_WRITE));
812 if (err < 0) {
813 dev_err(&client->dev, "Unable to write control register\n");
814 return -EIO;
815 }
816
817 /* Configure RV1805 specifics */
818 if (part == RV1805) {
819 /*
820 * Avoid accidentally entering test mode. This can happen
821 * on the RV1805 in case the reserved bit 5 in control2
822 * register is set. RV-1805-C3 datasheet indicates that
823 * the bit should be cleared in section 11h - Control2.
824 */
825 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
826 if (data < 0) {
827 dev_err(&client->dev,
828 "Unable to read control2 register\n");
829 return -EIO;
830 }
831
832 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
833 data & ~ABX8XX_CTRL2_RSVD);
834 if (err < 0) {
835 dev_err(&client->dev,
836 "Unable to write control2 register\n");
837 return -EIO;
838 }
839
840 /*
841 * Avoid extra power leakage. The RV1805 uses smaller
842 * 10pin package and the EXTI input is not present.
843 * Disable it to avoid leakage.
844 */
845 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
846 if (data < 0) {
847 dev_err(&client->dev,
848 "Unable to read output control register\n");
849 return -EIO;
850 }
851
852 /*
853 * Write the configuration key register to enable access to
854 * the config2 register
855 */
856 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
857 return -EIO;
858
859 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
860 data | ABX8XX_OUT_CTRL_EXDS);
861 if (err < 0) {
862 dev_err(&client->dev,
863 "Unable to write output control register\n");
864 return -EIO;
865 }
866 }
867
868 /* part autodetection */
869 if (part == ABX80X) {
870 for (i = 0; abx80x_caps[i].pn; i++)
871 if (partnumber == abx80x_caps[i].pn)
872 break;
873 if (abx80x_caps[i].pn == 0) {
874 dev_err(&client->dev, "Unknown part: %04x\n",
875 partnumber);
876 return -EINVAL;
877 }
878 part = i;
879 }
880
881 if (partnumber != abx80x_caps[part].pn) {
882 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
883 partnumber, abx80x_caps[part].pn);
884 return -EINVAL;
885 }
886
887 if (np && abx80x_caps[part].has_tc)
888 trickle_cfg = abx80x_dt_trickle_cfg(client);
889
890 if (trickle_cfg > 0) {
891 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
892 trickle_cfg);
893 abx80x_enable_trickle_charger(client, trickle_cfg);
894 }
895
896 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
897 BIT(2));
898 if (err)
899 return err;
900
901 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
902 if (priv == NULL)
903 return -ENOMEM;
904
905 priv->rtc = devm_rtc_allocate_device(&client->dev);
906 if (IS_ERR(priv->rtc))
907 return PTR_ERR(priv->rtc);
908
909 priv->rtc->ops = &abx80x_rtc_ops;
910 priv->client = client;
911
912 i2c_set_clientdata(client, priv);
913
914 if (abx80x_caps[part].has_wdog) {
915 err = abx80x_setup_watchdog(priv);
916 if (err)
917 return err;
918 }
919
920 err = abx80x_setup_nvmem(priv);
921 if (err)
922 return err;
923
924 if (client->irq > 0) {
925 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
926 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
927 abx80x_handle_irq,
928 IRQF_SHARED | IRQF_ONESHOT,
929 "abx8xx",
930 client);
931 if (err) {
932 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
933 client->irq = 0;
934 }
935 }
936
937 err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
938 if (err) {
939 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
940 err);
941 return err;
942 }
943
944 return devm_rtc_register_device(priv->rtc);
945}
946
947#ifdef CONFIG_OF
948static const struct of_device_id abx80x_of_match[] = {
949 {
950 .compatible = "abracon,abx80x",
951 .data = (void *)ABX80X
952 },
953 {
954 .compatible = "abracon,ab0801",
955 .data = (void *)AB0801
956 },
957 {
958 .compatible = "abracon,ab0803",
959 .data = (void *)AB0803
960 },
961 {
962 .compatible = "abracon,ab0804",
963 .data = (void *)AB0804
964 },
965 {
966 .compatible = "abracon,ab0805",
967 .data = (void *)AB0805
968 },
969 {
970 .compatible = "abracon,ab1801",
971 .data = (void *)AB1801
972 },
973 {
974 .compatible = "abracon,ab1803",
975 .data = (void *)AB1803
976 },
977 {
978 .compatible = "abracon,ab1804",
979 .data = (void *)AB1804
980 },
981 {
982 .compatible = "abracon,ab1805",
983 .data = (void *)AB1805
984 },
985 {
986 .compatible = "microcrystal,rv1805",
987 .data = (void *)RV1805
988 },
989 { }
990};
991MODULE_DEVICE_TABLE(of, abx80x_of_match);
992#endif
993
994static struct i2c_driver abx80x_driver = {
995 .driver = {
996 .name = "rtc-abx80x",
997 .of_match_table = of_match_ptr(abx80x_of_match),
998 },
999 .probe = abx80x_probe,
1000 .id_table = abx80x_id,
1001};
1002
1003module_i2c_driver(abx80x_driver);
1004
1005MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
1006MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1007MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
1008MODULE_LICENSE("GPL v2");