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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/i2c.h>
15#include <linux/kstrtox.h>
16#include <linux/module.h>
17#include <linux/of_device.h>
18#include <linux/rtc.h>
19#include <linux/watchdog.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#define ABX8XX_STATUS_BLF BIT(4)
41#define ABX8XX_STATUS_WDT BIT(6)
42
43#define ABX8XX_REG_CTRL1 0x10
44#define ABX8XX_CTRL_WRITE BIT(0)
45#define ABX8XX_CTRL_ARST BIT(2)
46#define ABX8XX_CTRL_12_24 BIT(6)
47
48#define ABX8XX_REG_CTRL2 0x11
49#define ABX8XX_CTRL2_RSVD BIT(5)
50
51#define ABX8XX_REG_IRQ 0x12
52#define ABX8XX_IRQ_AIE BIT(2)
53#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
54
55#define ABX8XX_REG_CD_TIMER_CTL 0x18
56
57#define ABX8XX_REG_OSC 0x1c
58#define ABX8XX_OSC_FOS BIT(3)
59#define ABX8XX_OSC_BOS BIT(4)
60#define ABX8XX_OSC_ACAL_512 BIT(5)
61#define ABX8XX_OSC_ACAL_1024 BIT(6)
62
63#define ABX8XX_OSC_OSEL BIT(7)
64
65#define ABX8XX_REG_OSS 0x1d
66#define ABX8XX_OSS_OF BIT(1)
67#define ABX8XX_OSS_OMODE BIT(4)
68
69#define ABX8XX_REG_WDT 0x1b
70#define ABX8XX_WDT_WDS BIT(7)
71#define ABX8XX_WDT_BMB_MASK 0x7c
72#define ABX8XX_WDT_BMB_SHIFT 2
73#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
74#define ABX8XX_WDT_WRB_MASK 0x03
75#define ABX8XX_WDT_WRB_1HZ 0x02
76
77#define ABX8XX_REG_CFG_KEY 0x1f
78#define ABX8XX_CFG_KEY_OSC 0xa1
79#define ABX8XX_CFG_KEY_MISC 0x9d
80
81#define ABX8XX_REG_ID0 0x28
82
83#define ABX8XX_REG_OUT_CTRL 0x30
84#define ABX8XX_OUT_CTRL_EXDS BIT(4)
85
86#define ABX8XX_REG_TRICKLE 0x20
87#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
88#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
89#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
90
91static u8 trickle_resistors[] = {0, 3, 6, 11};
92
93enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
94 AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
95
96struct abx80x_cap {
97 u16 pn;
98 bool has_tc;
99 bool has_wdog;
100};
101
102static struct abx80x_cap abx80x_caps[] = {
103 [AB0801] = {.pn = 0x0801},
104 [AB0803] = {.pn = 0x0803},
105 [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
106 [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
107 [AB1801] = {.pn = 0x1801},
108 [AB1803] = {.pn = 0x1803},
109 [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
110 [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
111 [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
112 [ABX80X] = {.pn = 0}
113};
114
115struct abx80x_priv {
116 struct rtc_device *rtc;
117 struct i2c_client *client;
118 struct watchdog_device wdog;
119};
120
121static int abx80x_write_config_key(struct i2c_client *client, u8 key)
122{
123 if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
124 dev_err(&client->dev, "Unable to write configuration key\n");
125 return -EIO;
126 }
127
128 return 0;
129}
130
131static int abx80x_is_rc_mode(struct i2c_client *client)
132{
133 int flags = 0;
134
135 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
136 if (flags < 0) {
137 dev_err(&client->dev,
138 "Failed to read autocalibration attribute\n");
139 return flags;
140 }
141
142 return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
143}
144
145static int abx80x_enable_trickle_charger(struct i2c_client *client,
146 u8 trickle_cfg)
147{
148 int err;
149
150 /*
151 * Write the configuration key register to enable access to the Trickle
152 * register
153 */
154 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
155 return -EIO;
156
157 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
158 ABX8XX_TRICKLE_CHARGE_ENABLE |
159 trickle_cfg);
160 if (err < 0) {
161 dev_err(&client->dev, "Unable to write trickle register\n");
162 return -EIO;
163 }
164
165 return 0;
166}
167
168static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
169{
170 struct i2c_client *client = to_i2c_client(dev);
171 unsigned char buf[8];
172 int err, flags, rc_mode = 0;
173
174 /* Read the Oscillator Failure only in XT mode */
175 rc_mode = abx80x_is_rc_mode(client);
176 if (rc_mode < 0)
177 return rc_mode;
178
179 if (!rc_mode) {
180 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
181 if (flags < 0)
182 return flags;
183
184 if (flags & ABX8XX_OSS_OF) {
185 dev_err(dev, "Oscillator failure, data is invalid.\n");
186 return -EINVAL;
187 }
188 }
189
190 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
191 sizeof(buf), buf);
192 if (err < 0) {
193 dev_err(&client->dev, "Unable to read date\n");
194 return -EIO;
195 }
196
197 tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
198 tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
199 tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
200 tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
201 tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
202 tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
203 tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
204
205 return 0;
206}
207
208static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
209{
210 struct i2c_client *client = to_i2c_client(dev);
211 unsigned char buf[8];
212 int err, flags;
213
214 if (tm->tm_year < 100)
215 return -EINVAL;
216
217 buf[ABX8XX_REG_HTH] = 0;
218 buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
219 buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
220 buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
221 buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
222 buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
223 buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
224 buf[ABX8XX_REG_WD] = tm->tm_wday;
225
226 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
227 sizeof(buf), buf);
228 if (err < 0) {
229 dev_err(&client->dev, "Unable to write to date registers\n");
230 return -EIO;
231 }
232
233 /* Clear the OF bit of Oscillator Status Register */
234 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
235 if (flags < 0)
236 return flags;
237
238 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
239 flags & ~ABX8XX_OSS_OF);
240 if (err < 0) {
241 dev_err(&client->dev, "Unable to write oscillator status register\n");
242 return err;
243 }
244
245 return 0;
246}
247
248static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
249{
250 struct i2c_client *client = dev_id;
251 struct abx80x_priv *priv = i2c_get_clientdata(client);
252 struct rtc_device *rtc = priv->rtc;
253 int status;
254
255 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
256 if (status < 0)
257 return IRQ_NONE;
258
259 if (status & ABX8XX_STATUS_AF)
260 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
261
262 /*
263 * It is unclear if we'll get an interrupt before the external
264 * reset kicks in.
265 */
266 if (status & ABX8XX_STATUS_WDT)
267 dev_alert(&client->dev, "watchdog timeout interrupt.\n");
268
269 i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
270
271 return IRQ_HANDLED;
272}
273
274static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
275{
276 struct i2c_client *client = to_i2c_client(dev);
277 unsigned char buf[7];
278
279 int irq_mask, err;
280
281 if (client->irq <= 0)
282 return -EINVAL;
283
284 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
285 sizeof(buf), buf);
286 if (err)
287 return err;
288
289 irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
290 if (irq_mask < 0)
291 return irq_mask;
292
293 t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
294 t->time.tm_min = bcd2bin(buf[1] & 0x7F);
295 t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
296 t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
297 t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
298 t->time.tm_wday = buf[5] & 0x7;
299
300 t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
301 t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
302
303 return err;
304}
305
306static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
307{
308 struct i2c_client *client = to_i2c_client(dev);
309 u8 alarm[6];
310 int err;
311
312 if (client->irq <= 0)
313 return -EINVAL;
314
315 alarm[0] = 0x0;
316 alarm[1] = bin2bcd(t->time.tm_sec);
317 alarm[2] = bin2bcd(t->time.tm_min);
318 alarm[3] = bin2bcd(t->time.tm_hour);
319 alarm[4] = bin2bcd(t->time.tm_mday);
320 alarm[5] = bin2bcd(t->time.tm_mon + 1);
321
322 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
323 sizeof(alarm), alarm);
324 if (err < 0) {
325 dev_err(&client->dev, "Unable to write alarm registers\n");
326 return -EIO;
327 }
328
329 if (t->enabled) {
330 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
331 (ABX8XX_IRQ_IM_1_4 |
332 ABX8XX_IRQ_AIE));
333 if (err)
334 return err;
335 }
336
337 return 0;
338}
339
340static int abx80x_rtc_set_autocalibration(struct device *dev,
341 int autocalibration)
342{
343 struct i2c_client *client = to_i2c_client(dev);
344 int retval, flags = 0;
345
346 if ((autocalibration != 0) && (autocalibration != 1024) &&
347 (autocalibration != 512)) {
348 dev_err(dev, "autocalibration value outside permitted range\n");
349 return -EINVAL;
350 }
351
352 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
353 if (flags < 0)
354 return flags;
355
356 if (autocalibration == 0) {
357 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
358 } else if (autocalibration == 1024) {
359 /* 1024 autocalibration is 0x10 */
360 flags |= ABX8XX_OSC_ACAL_1024;
361 flags &= ~(ABX8XX_OSC_ACAL_512);
362 } else {
363 /* 512 autocalibration is 0x11 */
364 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
365 }
366
367 /* Unlock write access to Oscillator Control Register */
368 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
369 return -EIO;
370
371 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
372
373 return retval;
374}
375
376static int abx80x_rtc_get_autocalibration(struct device *dev)
377{
378 struct i2c_client *client = to_i2c_client(dev);
379 int flags = 0, autocalibration;
380
381 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
382 if (flags < 0)
383 return flags;
384
385 if (flags & ABX8XX_OSC_ACAL_512)
386 autocalibration = 512;
387 else if (flags & ABX8XX_OSC_ACAL_1024)
388 autocalibration = 1024;
389 else
390 autocalibration = 0;
391
392 return autocalibration;
393}
394
395static ssize_t autocalibration_store(struct device *dev,
396 struct device_attribute *attr,
397 const char *buf, size_t count)
398{
399 int retval;
400 unsigned long autocalibration = 0;
401
402 retval = kstrtoul(buf, 10, &autocalibration);
403 if (retval < 0) {
404 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
405 return -EINVAL;
406 }
407
408 retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
409
410 return retval ? retval : count;
411}
412
413static ssize_t autocalibration_show(struct device *dev,
414 struct device_attribute *attr, char *buf)
415{
416 int autocalibration = 0;
417
418 autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
419 if (autocalibration < 0) {
420 dev_err(dev, "Failed to read RTC autocalibration\n");
421 sprintf(buf, "0\n");
422 return autocalibration;
423 }
424
425 return sprintf(buf, "%d\n", autocalibration);
426}
427
428static DEVICE_ATTR_RW(autocalibration);
429
430static ssize_t oscillator_store(struct device *dev,
431 struct device_attribute *attr,
432 const char *buf, size_t count)
433{
434 struct i2c_client *client = to_i2c_client(dev->parent);
435 int retval, flags, rc_mode = 0;
436
437 if (strncmp(buf, "rc", 2) == 0) {
438 rc_mode = 1;
439 } else if (strncmp(buf, "xtal", 4) == 0) {
440 rc_mode = 0;
441 } else {
442 dev_err(dev, "Oscillator selection value outside permitted ones\n");
443 return -EINVAL;
444 }
445
446 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
447 if (flags < 0)
448 return flags;
449
450 if (rc_mode == 0)
451 flags &= ~(ABX8XX_OSC_OSEL);
452 else
453 flags |= (ABX8XX_OSC_OSEL);
454
455 /* Unlock write access on Oscillator Control register */
456 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
457 return -EIO;
458
459 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
460 if (retval < 0) {
461 dev_err(dev, "Failed to write Oscillator Control register\n");
462 return retval;
463 }
464
465 return retval ? retval : count;
466}
467
468static ssize_t oscillator_show(struct device *dev,
469 struct device_attribute *attr, char *buf)
470{
471 int rc_mode = 0;
472 struct i2c_client *client = to_i2c_client(dev->parent);
473
474 rc_mode = abx80x_is_rc_mode(client);
475
476 if (rc_mode < 0) {
477 dev_err(dev, "Failed to read RTC oscillator selection\n");
478 sprintf(buf, "\n");
479 return rc_mode;
480 }
481
482 if (rc_mode)
483 return sprintf(buf, "rc\n");
484 else
485 return sprintf(buf, "xtal\n");
486}
487
488static DEVICE_ATTR_RW(oscillator);
489
490static struct attribute *rtc_calib_attrs[] = {
491 &dev_attr_autocalibration.attr,
492 &dev_attr_oscillator.attr,
493 NULL,
494};
495
496static const struct attribute_group rtc_calib_attr_group = {
497 .attrs = rtc_calib_attrs,
498};
499
500static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
501{
502 struct i2c_client *client = to_i2c_client(dev);
503 int err;
504
505 if (enabled)
506 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
507 (ABX8XX_IRQ_IM_1_4 |
508 ABX8XX_IRQ_AIE));
509 else
510 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
511 ABX8XX_IRQ_IM_1_4);
512 return err;
513}
514
515static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
516{
517 struct i2c_client *client = to_i2c_client(dev);
518 int status, tmp;
519
520 switch (cmd) {
521 case RTC_VL_READ:
522 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
523 if (status < 0)
524 return status;
525
526 tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
527
528 return put_user(tmp, (unsigned int __user *)arg);
529
530 case RTC_VL_CLR:
531 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
532 if (status < 0)
533 return status;
534
535 status &= ~ABX8XX_STATUS_BLF;
536
537 tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
538 if (tmp < 0)
539 return tmp;
540
541 return 0;
542
543 default:
544 return -ENOIOCTLCMD;
545 }
546}
547
548static const struct rtc_class_ops abx80x_rtc_ops = {
549 .read_time = abx80x_rtc_read_time,
550 .set_time = abx80x_rtc_set_time,
551 .read_alarm = abx80x_read_alarm,
552 .set_alarm = abx80x_set_alarm,
553 .alarm_irq_enable = abx80x_alarm_irq_enable,
554 .ioctl = abx80x_ioctl,
555};
556
557static int abx80x_dt_trickle_cfg(struct i2c_client *client)
558{
559 struct device_node *np = client->dev.of_node;
560 const char *diode;
561 int trickle_cfg = 0;
562 int i, ret;
563 u32 tmp;
564
565 ret = of_property_read_string(np, "abracon,tc-diode", &diode);
566 if (ret)
567 return ret;
568
569 if (!strcmp(diode, "standard")) {
570 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
571 } else if (!strcmp(diode, "schottky")) {
572 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
573 } else {
574 dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
575 return -EINVAL;
576 }
577
578 ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
579 if (ret)
580 return ret;
581
582 for (i = 0; i < sizeof(trickle_resistors); i++)
583 if (trickle_resistors[i] == tmp)
584 break;
585
586 if (i == sizeof(trickle_resistors)) {
587 dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
588 return -EINVAL;
589 }
590
591 return (trickle_cfg | i);
592}
593
594#ifdef CONFIG_WATCHDOG
595
596static inline u8 timeout_bits(unsigned int timeout)
597{
598 return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
599 ABX8XX_WDT_WRB_1HZ;
600}
601
602static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
603 unsigned int timeout)
604{
605 struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
606 u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
607
608 /*
609 * Writing any timeout to the WDT register resets the watchdog timer.
610 * Writing 0 disables it.
611 */
612 return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
613}
614
615static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
616 unsigned int new_timeout)
617{
618 int err = 0;
619
620 if (watchdog_hw_running(wdog))
621 err = __abx80x_wdog_set_timeout(wdog, new_timeout);
622
623 if (err == 0)
624 wdog->timeout = new_timeout;
625
626 return err;
627}
628
629static int abx80x_wdog_ping(struct watchdog_device *wdog)
630{
631 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
632}
633
634static int abx80x_wdog_start(struct watchdog_device *wdog)
635{
636 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
637}
638
639static int abx80x_wdog_stop(struct watchdog_device *wdog)
640{
641 return __abx80x_wdog_set_timeout(wdog, 0);
642}
643
644static const struct watchdog_info abx80x_wdog_info = {
645 .identity = "abx80x watchdog",
646 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
647};
648
649static const struct watchdog_ops abx80x_wdog_ops = {
650 .owner = THIS_MODULE,
651 .start = abx80x_wdog_start,
652 .stop = abx80x_wdog_stop,
653 .ping = abx80x_wdog_ping,
654 .set_timeout = abx80x_wdog_set_timeout,
655};
656
657static int abx80x_setup_watchdog(struct abx80x_priv *priv)
658{
659 priv->wdog.parent = &priv->client->dev;
660 priv->wdog.ops = &abx80x_wdog_ops;
661 priv->wdog.info = &abx80x_wdog_info;
662 priv->wdog.min_timeout = 1;
663 priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
664 priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
665
666 watchdog_set_drvdata(&priv->wdog, priv);
667
668 return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
669}
670#else
671static int abx80x_setup_watchdog(struct abx80x_priv *priv)
672{
673 return 0;
674}
675#endif
676
677static const struct i2c_device_id abx80x_id[] = {
678 { "abx80x", ABX80X },
679 { "ab0801", AB0801 },
680 { "ab0803", AB0803 },
681 { "ab0804", AB0804 },
682 { "ab0805", AB0805 },
683 { "ab1801", AB1801 },
684 { "ab1803", AB1803 },
685 { "ab1804", AB1804 },
686 { "ab1805", AB1805 },
687 { "rv1805", RV1805 },
688 { }
689};
690MODULE_DEVICE_TABLE(i2c, abx80x_id);
691
692static int abx80x_probe(struct i2c_client *client)
693{
694 struct device_node *np = client->dev.of_node;
695 struct abx80x_priv *priv;
696 int i, data, err, trickle_cfg = -EINVAL;
697 char buf[7];
698 const struct i2c_device_id *id = i2c_match_id(abx80x_id, client);
699 unsigned int part = id->driver_data;
700 unsigned int partnumber;
701 unsigned int majrev, minrev;
702 unsigned int lot;
703 unsigned int wafer;
704 unsigned int uid;
705
706 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
707 return -ENODEV;
708
709 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
710 sizeof(buf), buf);
711 if (err < 0) {
712 dev_err(&client->dev, "Unable to read partnumber\n");
713 return -EIO;
714 }
715
716 partnumber = (buf[0] << 8) | buf[1];
717 majrev = buf[2] >> 3;
718 minrev = buf[2] & 0x7;
719 lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
720 uid = ((buf[4] & 0x7f) << 8) | buf[5];
721 wafer = (buf[6] & 0x7c) >> 2;
722 dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
723 partnumber, majrev, minrev, lot, wafer, uid);
724
725 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
726 if (data < 0) {
727 dev_err(&client->dev, "Unable to read control register\n");
728 return -EIO;
729 }
730
731 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
732 ((data & ~(ABX8XX_CTRL_12_24 |
733 ABX8XX_CTRL_ARST)) |
734 ABX8XX_CTRL_WRITE));
735 if (err < 0) {
736 dev_err(&client->dev, "Unable to write control register\n");
737 return -EIO;
738 }
739
740 /* Configure RV1805 specifics */
741 if (part == RV1805) {
742 /*
743 * Avoid accidentally entering test mode. This can happen
744 * on the RV1805 in case the reserved bit 5 in control2
745 * register is set. RV-1805-C3 datasheet indicates that
746 * the bit should be cleared in section 11h - Control2.
747 */
748 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
749 if (data < 0) {
750 dev_err(&client->dev,
751 "Unable to read control2 register\n");
752 return -EIO;
753 }
754
755 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
756 data & ~ABX8XX_CTRL2_RSVD);
757 if (err < 0) {
758 dev_err(&client->dev,
759 "Unable to write control2 register\n");
760 return -EIO;
761 }
762
763 /*
764 * Avoid extra power leakage. The RV1805 uses smaller
765 * 10pin package and the EXTI input is not present.
766 * Disable it to avoid leakage.
767 */
768 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
769 if (data < 0) {
770 dev_err(&client->dev,
771 "Unable to read output control register\n");
772 return -EIO;
773 }
774
775 /*
776 * Write the configuration key register to enable access to
777 * the config2 register
778 */
779 if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
780 return -EIO;
781
782 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
783 data | ABX8XX_OUT_CTRL_EXDS);
784 if (err < 0) {
785 dev_err(&client->dev,
786 "Unable to write output control register\n");
787 return -EIO;
788 }
789 }
790
791 /* part autodetection */
792 if (part == ABX80X) {
793 for (i = 0; abx80x_caps[i].pn; i++)
794 if (partnumber == abx80x_caps[i].pn)
795 break;
796 if (abx80x_caps[i].pn == 0) {
797 dev_err(&client->dev, "Unknown part: %04x\n",
798 partnumber);
799 return -EINVAL;
800 }
801 part = i;
802 }
803
804 if (partnumber != abx80x_caps[part].pn) {
805 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
806 partnumber, abx80x_caps[part].pn);
807 return -EINVAL;
808 }
809
810 if (np && abx80x_caps[part].has_tc)
811 trickle_cfg = abx80x_dt_trickle_cfg(client);
812
813 if (trickle_cfg > 0) {
814 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
815 trickle_cfg);
816 abx80x_enable_trickle_charger(client, trickle_cfg);
817 }
818
819 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
820 BIT(2));
821 if (err)
822 return err;
823
824 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
825 if (priv == NULL)
826 return -ENOMEM;
827
828 priv->rtc = devm_rtc_allocate_device(&client->dev);
829 if (IS_ERR(priv->rtc))
830 return PTR_ERR(priv->rtc);
831
832 priv->rtc->ops = &abx80x_rtc_ops;
833 priv->client = client;
834
835 i2c_set_clientdata(client, priv);
836
837 if (abx80x_caps[part].has_wdog) {
838 err = abx80x_setup_watchdog(priv);
839 if (err)
840 return err;
841 }
842
843 if (client->irq > 0) {
844 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
845 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
846 abx80x_handle_irq,
847 IRQF_SHARED | IRQF_ONESHOT,
848 "abx8xx",
849 client);
850 if (err) {
851 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
852 client->irq = 0;
853 }
854 }
855
856 err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
857 if (err) {
858 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
859 err);
860 return err;
861 }
862
863 return devm_rtc_register_device(priv->rtc);
864}
865
866#ifdef CONFIG_OF
867static const struct of_device_id abx80x_of_match[] = {
868 {
869 .compatible = "abracon,abx80x",
870 .data = (void *)ABX80X
871 },
872 {
873 .compatible = "abracon,ab0801",
874 .data = (void *)AB0801
875 },
876 {
877 .compatible = "abracon,ab0803",
878 .data = (void *)AB0803
879 },
880 {
881 .compatible = "abracon,ab0804",
882 .data = (void *)AB0804
883 },
884 {
885 .compatible = "abracon,ab0805",
886 .data = (void *)AB0805
887 },
888 {
889 .compatible = "abracon,ab1801",
890 .data = (void *)AB1801
891 },
892 {
893 .compatible = "abracon,ab1803",
894 .data = (void *)AB1803
895 },
896 {
897 .compatible = "abracon,ab1804",
898 .data = (void *)AB1804
899 },
900 {
901 .compatible = "abracon,ab1805",
902 .data = (void *)AB1805
903 },
904 {
905 .compatible = "microcrystal,rv1805",
906 .data = (void *)RV1805
907 },
908 { }
909};
910MODULE_DEVICE_TABLE(of, abx80x_of_match);
911#endif
912
913static struct i2c_driver abx80x_driver = {
914 .driver = {
915 .name = "rtc-abx80x",
916 .of_match_table = of_match_ptr(abx80x_of_match),
917 },
918 .probe_new = abx80x_probe,
919 .id_table = abx80x_id,
920};
921
922module_i2c_driver(abx80x_driver);
923
924MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
925MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
926MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
927MODULE_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/i2c.h>
15#include <linux/module.h>
16#include <linux/rtc.h>
17#include <linux/watchdog.h>
18
19#define ABX8XX_REG_HTH 0x00
20#define ABX8XX_REG_SC 0x01
21#define ABX8XX_REG_MN 0x02
22#define ABX8XX_REG_HR 0x03
23#define ABX8XX_REG_DA 0x04
24#define ABX8XX_REG_MO 0x05
25#define ABX8XX_REG_YR 0x06
26#define ABX8XX_REG_WD 0x07
27
28#define ABX8XX_REG_AHTH 0x08
29#define ABX8XX_REG_ASC 0x09
30#define ABX8XX_REG_AMN 0x0a
31#define ABX8XX_REG_AHR 0x0b
32#define ABX8XX_REG_ADA 0x0c
33#define ABX8XX_REG_AMO 0x0d
34#define ABX8XX_REG_AWD 0x0e
35
36#define ABX8XX_REG_STATUS 0x0f
37#define ABX8XX_STATUS_AF BIT(2)
38#define ABX8XX_STATUS_BLF BIT(4)
39#define ABX8XX_STATUS_WDT BIT(6)
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_CTRL2 0x11
47#define ABX8XX_CTRL2_RSVD BIT(5)
48
49#define ABX8XX_REG_IRQ 0x12
50#define ABX8XX_IRQ_AIE BIT(2)
51#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
52
53#define ABX8XX_REG_CD_TIMER_CTL 0x18
54
55#define ABX8XX_REG_OSC 0x1c
56#define ABX8XX_OSC_FOS BIT(3)
57#define ABX8XX_OSC_BOS BIT(4)
58#define ABX8XX_OSC_ACAL_512 BIT(5)
59#define ABX8XX_OSC_ACAL_1024 BIT(6)
60
61#define ABX8XX_OSC_OSEL BIT(7)
62
63#define ABX8XX_REG_OSS 0x1d
64#define ABX8XX_OSS_OF BIT(1)
65#define ABX8XX_OSS_OMODE BIT(4)
66
67#define ABX8XX_REG_WDT 0x1b
68#define ABX8XX_WDT_WDS BIT(7)
69#define ABX8XX_WDT_BMB_MASK 0x7c
70#define ABX8XX_WDT_BMB_SHIFT 2
71#define ABX8XX_WDT_MAX_TIME (ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
72#define ABX8XX_WDT_WRB_MASK 0x03
73#define ABX8XX_WDT_WRB_1HZ 0x02
74
75#define ABX8XX_REG_CFG_KEY 0x1f
76#define ABX8XX_CFG_KEY_OSC 0xa1
77#define ABX8XX_CFG_KEY_MISC 0x9d
78
79#define ABX8XX_REG_ID0 0x28
80
81#define ABX8XX_REG_OUT_CTRL 0x30
82#define ABX8XX_OUT_CTRL_EXDS BIT(4)
83
84#define ABX8XX_REG_TRICKLE 0x20
85#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
86#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
87#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
88
89static u8 trickle_resistors[] = {0, 3, 6, 11};
90
91enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
92 AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
93
94struct abx80x_cap {
95 u16 pn;
96 bool has_tc;
97 bool has_wdog;
98};
99
100static struct abx80x_cap abx80x_caps[] = {
101 [AB0801] = {.pn = 0x0801},
102 [AB0803] = {.pn = 0x0803},
103 [AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
104 [AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
105 [AB1801] = {.pn = 0x1801},
106 [AB1803] = {.pn = 0x1803},
107 [AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
108 [AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
109 [RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
110 [ABX80X] = {.pn = 0}
111};
112
113struct abx80x_priv {
114 struct rtc_device *rtc;
115 struct i2c_client *client;
116 struct watchdog_device wdog;
117};
118
119static int abx80x_is_rc_mode(struct i2c_client *client)
120{
121 int flags = 0;
122
123 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
124 if (flags < 0) {
125 dev_err(&client->dev,
126 "Failed to read autocalibration attribute\n");
127 return flags;
128 }
129
130 return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
131}
132
133static int abx80x_enable_trickle_charger(struct i2c_client *client,
134 u8 trickle_cfg)
135{
136 int err;
137
138 /*
139 * Write the configuration key register to enable access to the Trickle
140 * register
141 */
142 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
143 ABX8XX_CFG_KEY_MISC);
144 if (err < 0) {
145 dev_err(&client->dev, "Unable to write configuration key\n");
146 return -EIO;
147 }
148
149 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
150 ABX8XX_TRICKLE_CHARGE_ENABLE |
151 trickle_cfg);
152 if (err < 0) {
153 dev_err(&client->dev, "Unable to write trickle register\n");
154 return -EIO;
155 }
156
157 return 0;
158}
159
160static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
161{
162 struct i2c_client *client = to_i2c_client(dev);
163 unsigned char buf[8];
164 int err, flags, rc_mode = 0;
165
166 /* Read the Oscillator Failure only in XT mode */
167 rc_mode = abx80x_is_rc_mode(client);
168 if (rc_mode < 0)
169 return rc_mode;
170
171 if (!rc_mode) {
172 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
173 if (flags < 0)
174 return flags;
175
176 if (flags & ABX8XX_OSS_OF) {
177 dev_err(dev, "Oscillator failure, data is invalid.\n");
178 return -EINVAL;
179 }
180 }
181
182 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
183 sizeof(buf), buf);
184 if (err < 0) {
185 dev_err(&client->dev, "Unable to read date\n");
186 return -EIO;
187 }
188
189 tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
190 tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
191 tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
192 tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
193 tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
194 tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
195 tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
196
197 return 0;
198}
199
200static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
201{
202 struct i2c_client *client = to_i2c_client(dev);
203 unsigned char buf[8];
204 int err, flags;
205
206 if (tm->tm_year < 100)
207 return -EINVAL;
208
209 buf[ABX8XX_REG_HTH] = 0;
210 buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
211 buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
212 buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
213 buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
214 buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
215 buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
216 buf[ABX8XX_REG_WD] = tm->tm_wday;
217
218 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
219 sizeof(buf), buf);
220 if (err < 0) {
221 dev_err(&client->dev, "Unable to write to date registers\n");
222 return -EIO;
223 }
224
225 /* Clear the OF bit of Oscillator Status Register */
226 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
227 if (flags < 0)
228 return flags;
229
230 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
231 flags & ~ABX8XX_OSS_OF);
232 if (err < 0) {
233 dev_err(&client->dev, "Unable to write oscillator status register\n");
234 return err;
235 }
236
237 return 0;
238}
239
240static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
241{
242 struct i2c_client *client = dev_id;
243 struct abx80x_priv *priv = i2c_get_clientdata(client);
244 struct rtc_device *rtc = priv->rtc;
245 int status;
246
247 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
248 if (status < 0)
249 return IRQ_NONE;
250
251 if (status & ABX8XX_STATUS_AF)
252 rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
253
254 /*
255 * It is unclear if we'll get an interrupt before the external
256 * reset kicks in.
257 */
258 if (status & ABX8XX_STATUS_WDT)
259 dev_alert(&client->dev, "watchdog timeout interrupt.\n");
260
261 i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
262
263 return IRQ_HANDLED;
264}
265
266static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
267{
268 struct i2c_client *client = to_i2c_client(dev);
269 unsigned char buf[7];
270
271 int irq_mask, err;
272
273 if (client->irq <= 0)
274 return -EINVAL;
275
276 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
277 sizeof(buf), buf);
278 if (err)
279 return err;
280
281 irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
282 if (irq_mask < 0)
283 return irq_mask;
284
285 t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
286 t->time.tm_min = bcd2bin(buf[1] & 0x7F);
287 t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
288 t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
289 t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
290 t->time.tm_wday = buf[5] & 0x7;
291
292 t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
293 t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
294
295 return err;
296}
297
298static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
299{
300 struct i2c_client *client = to_i2c_client(dev);
301 u8 alarm[6];
302 int err;
303
304 if (client->irq <= 0)
305 return -EINVAL;
306
307 alarm[0] = 0x0;
308 alarm[1] = bin2bcd(t->time.tm_sec);
309 alarm[2] = bin2bcd(t->time.tm_min);
310 alarm[3] = bin2bcd(t->time.tm_hour);
311 alarm[4] = bin2bcd(t->time.tm_mday);
312 alarm[5] = bin2bcd(t->time.tm_mon + 1);
313
314 err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
315 sizeof(alarm), alarm);
316 if (err < 0) {
317 dev_err(&client->dev, "Unable to write alarm registers\n");
318 return -EIO;
319 }
320
321 if (t->enabled) {
322 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
323 (ABX8XX_IRQ_IM_1_4 |
324 ABX8XX_IRQ_AIE));
325 if (err)
326 return err;
327 }
328
329 return 0;
330}
331
332static int abx80x_rtc_set_autocalibration(struct device *dev,
333 int autocalibration)
334{
335 struct i2c_client *client = to_i2c_client(dev);
336 int retval, flags = 0;
337
338 if ((autocalibration != 0) && (autocalibration != 1024) &&
339 (autocalibration != 512)) {
340 dev_err(dev, "autocalibration value outside permitted range\n");
341 return -EINVAL;
342 }
343
344 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
345 if (flags < 0)
346 return flags;
347
348 if (autocalibration == 0) {
349 flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
350 } else if (autocalibration == 1024) {
351 /* 1024 autocalibration is 0x10 */
352 flags |= ABX8XX_OSC_ACAL_1024;
353 flags &= ~(ABX8XX_OSC_ACAL_512);
354 } else {
355 /* 512 autocalibration is 0x11 */
356 flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
357 }
358
359 /* Unlock write access to Oscillator Control Register */
360 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
361 ABX8XX_CFG_KEY_OSC);
362 if (retval < 0) {
363 dev_err(dev, "Failed to write CONFIG_KEY register\n");
364 return retval;
365 }
366
367 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
368
369 return retval;
370}
371
372static int abx80x_rtc_get_autocalibration(struct device *dev)
373{
374 struct i2c_client *client = to_i2c_client(dev);
375 int flags = 0, autocalibration;
376
377 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
378 if (flags < 0)
379 return flags;
380
381 if (flags & ABX8XX_OSC_ACAL_512)
382 autocalibration = 512;
383 else if (flags & ABX8XX_OSC_ACAL_1024)
384 autocalibration = 1024;
385 else
386 autocalibration = 0;
387
388 return autocalibration;
389}
390
391static ssize_t autocalibration_store(struct device *dev,
392 struct device_attribute *attr,
393 const char *buf, size_t count)
394{
395 int retval;
396 unsigned long autocalibration = 0;
397
398 retval = kstrtoul(buf, 10, &autocalibration);
399 if (retval < 0) {
400 dev_err(dev, "Failed to store RTC autocalibration attribute\n");
401 return -EINVAL;
402 }
403
404 retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
405
406 return retval ? retval : count;
407}
408
409static ssize_t autocalibration_show(struct device *dev,
410 struct device_attribute *attr, char *buf)
411{
412 int autocalibration = 0;
413
414 autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
415 if (autocalibration < 0) {
416 dev_err(dev, "Failed to read RTC autocalibration\n");
417 sprintf(buf, "0\n");
418 return autocalibration;
419 }
420
421 return sprintf(buf, "%d\n", autocalibration);
422}
423
424static DEVICE_ATTR_RW(autocalibration);
425
426static ssize_t oscillator_store(struct device *dev,
427 struct device_attribute *attr,
428 const char *buf, size_t count)
429{
430 struct i2c_client *client = to_i2c_client(dev->parent);
431 int retval, flags, rc_mode = 0;
432
433 if (strncmp(buf, "rc", 2) == 0) {
434 rc_mode = 1;
435 } else if (strncmp(buf, "xtal", 4) == 0) {
436 rc_mode = 0;
437 } else {
438 dev_err(dev, "Oscillator selection value outside permitted ones\n");
439 return -EINVAL;
440 }
441
442 flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
443 if (flags < 0)
444 return flags;
445
446 if (rc_mode == 0)
447 flags &= ~(ABX8XX_OSC_OSEL);
448 else
449 flags |= (ABX8XX_OSC_OSEL);
450
451 /* Unlock write access on Oscillator Control register */
452 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
453 ABX8XX_CFG_KEY_OSC);
454 if (retval < 0) {
455 dev_err(dev, "Failed to write CONFIG_KEY register\n");
456 return retval;
457 }
458
459 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
460 if (retval < 0) {
461 dev_err(dev, "Failed to write Oscillator Control register\n");
462 return retval;
463 }
464
465 return retval ? retval : count;
466}
467
468static ssize_t oscillator_show(struct device *dev,
469 struct device_attribute *attr, char *buf)
470{
471 int rc_mode = 0;
472 struct i2c_client *client = to_i2c_client(dev->parent);
473
474 rc_mode = abx80x_is_rc_mode(client);
475
476 if (rc_mode < 0) {
477 dev_err(dev, "Failed to read RTC oscillator selection\n");
478 sprintf(buf, "\n");
479 return rc_mode;
480 }
481
482 if (rc_mode)
483 return sprintf(buf, "rc\n");
484 else
485 return sprintf(buf, "xtal\n");
486}
487
488static DEVICE_ATTR_RW(oscillator);
489
490static struct attribute *rtc_calib_attrs[] = {
491 &dev_attr_autocalibration.attr,
492 &dev_attr_oscillator.attr,
493 NULL,
494};
495
496static const struct attribute_group rtc_calib_attr_group = {
497 .attrs = rtc_calib_attrs,
498};
499
500static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
501{
502 struct i2c_client *client = to_i2c_client(dev);
503 int err;
504
505 if (enabled)
506 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
507 (ABX8XX_IRQ_IM_1_4 |
508 ABX8XX_IRQ_AIE));
509 else
510 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
511 ABX8XX_IRQ_IM_1_4);
512 return err;
513}
514
515static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
516{
517 struct i2c_client *client = to_i2c_client(dev);
518 int status, tmp;
519
520 switch (cmd) {
521 case RTC_VL_READ:
522 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
523 if (status < 0)
524 return status;
525
526 tmp = !!(status & ABX8XX_STATUS_BLF);
527
528 if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
529 return -EFAULT;
530
531 return 0;
532
533 case RTC_VL_CLR:
534 status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
535 if (status < 0)
536 return status;
537
538 status &= ~ABX8XX_STATUS_BLF;
539
540 tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
541 if (tmp < 0)
542 return tmp;
543
544 return 0;
545
546 default:
547 return -ENOIOCTLCMD;
548 }
549}
550
551static const struct rtc_class_ops abx80x_rtc_ops = {
552 .read_time = abx80x_rtc_read_time,
553 .set_time = abx80x_rtc_set_time,
554 .read_alarm = abx80x_read_alarm,
555 .set_alarm = abx80x_set_alarm,
556 .alarm_irq_enable = abx80x_alarm_irq_enable,
557 .ioctl = abx80x_ioctl,
558};
559
560static int abx80x_dt_trickle_cfg(struct device_node *np)
561{
562 const char *diode;
563 int trickle_cfg = 0;
564 int i, ret;
565 u32 tmp;
566
567 ret = of_property_read_string(np, "abracon,tc-diode", &diode);
568 if (ret)
569 return ret;
570
571 if (!strcmp(diode, "standard"))
572 trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
573 else if (!strcmp(diode, "schottky"))
574 trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
575 else
576 return -EINVAL;
577
578 ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
579 if (ret)
580 return ret;
581
582 for (i = 0; i < sizeof(trickle_resistors); i++)
583 if (trickle_resistors[i] == tmp)
584 break;
585
586 if (i == sizeof(trickle_resistors))
587 return -EINVAL;
588
589 return (trickle_cfg | i);
590}
591
592#ifdef CONFIG_WATCHDOG
593
594static inline u8 timeout_bits(unsigned int timeout)
595{
596 return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
597 ABX8XX_WDT_WRB_1HZ;
598}
599
600static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
601 unsigned int timeout)
602{
603 struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
604 u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
605
606 /*
607 * Writing any timeout to the WDT register resets the watchdog timer.
608 * Writing 0 disables it.
609 */
610 return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
611}
612
613static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
614 unsigned int new_timeout)
615{
616 int err = 0;
617
618 if (watchdog_hw_running(wdog))
619 err = __abx80x_wdog_set_timeout(wdog, new_timeout);
620
621 if (err == 0)
622 wdog->timeout = new_timeout;
623
624 return err;
625}
626
627static int abx80x_wdog_ping(struct watchdog_device *wdog)
628{
629 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
630}
631
632static int abx80x_wdog_start(struct watchdog_device *wdog)
633{
634 return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
635}
636
637static int abx80x_wdog_stop(struct watchdog_device *wdog)
638{
639 return __abx80x_wdog_set_timeout(wdog, 0);
640}
641
642static const struct watchdog_info abx80x_wdog_info = {
643 .identity = "abx80x watchdog",
644 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
645};
646
647static const struct watchdog_ops abx80x_wdog_ops = {
648 .owner = THIS_MODULE,
649 .start = abx80x_wdog_start,
650 .stop = abx80x_wdog_stop,
651 .ping = abx80x_wdog_ping,
652 .set_timeout = abx80x_wdog_set_timeout,
653};
654
655static int abx80x_setup_watchdog(struct abx80x_priv *priv)
656{
657 priv->wdog.parent = &priv->client->dev;
658 priv->wdog.ops = &abx80x_wdog_ops;
659 priv->wdog.info = &abx80x_wdog_info;
660 priv->wdog.min_timeout = 1;
661 priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
662 priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
663
664 watchdog_set_drvdata(&priv->wdog, priv);
665
666 return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
667}
668#else
669static int abx80x_setup_watchdog(struct abx80x_priv *priv)
670{
671 return 0;
672}
673#endif
674
675static int abx80x_probe(struct i2c_client *client,
676 const struct i2c_device_id *id)
677{
678 struct device_node *np = client->dev.of_node;
679 struct abx80x_priv *priv;
680 int i, data, err, trickle_cfg = -EINVAL;
681 char buf[7];
682 unsigned int part = id->driver_data;
683 unsigned int partnumber;
684 unsigned int majrev, minrev;
685 unsigned int lot;
686 unsigned int wafer;
687 unsigned int uid;
688
689 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
690 return -ENODEV;
691
692 err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
693 sizeof(buf), buf);
694 if (err < 0) {
695 dev_err(&client->dev, "Unable to read partnumber\n");
696 return -EIO;
697 }
698
699 partnumber = (buf[0] << 8) | buf[1];
700 majrev = buf[2] >> 3;
701 minrev = buf[2] & 0x7;
702 lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
703 uid = ((buf[4] & 0x7f) << 8) | buf[5];
704 wafer = (buf[6] & 0x7c) >> 2;
705 dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
706 partnumber, majrev, minrev, lot, wafer, uid);
707
708 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
709 if (data < 0) {
710 dev_err(&client->dev, "Unable to read control register\n");
711 return -EIO;
712 }
713
714 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
715 ((data & ~(ABX8XX_CTRL_12_24 |
716 ABX8XX_CTRL_ARST)) |
717 ABX8XX_CTRL_WRITE));
718 if (err < 0) {
719 dev_err(&client->dev, "Unable to write control register\n");
720 return -EIO;
721 }
722
723 /* Configure RV1805 specifics */
724 if (part == RV1805) {
725 /*
726 * Avoid accidentally entering test mode. This can happen
727 * on the RV1805 in case the reserved bit 5 in control2
728 * register is set. RV-1805-C3 datasheet indicates that
729 * the bit should be cleared in section 11h - Control2.
730 */
731 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
732 if (data < 0) {
733 dev_err(&client->dev,
734 "Unable to read control2 register\n");
735 return -EIO;
736 }
737
738 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
739 data & ~ABX8XX_CTRL2_RSVD);
740 if (err < 0) {
741 dev_err(&client->dev,
742 "Unable to write control2 register\n");
743 return -EIO;
744 }
745
746 /*
747 * Avoid extra power leakage. The RV1805 uses smaller
748 * 10pin package and the EXTI input is not present.
749 * Disable it to avoid leakage.
750 */
751 data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
752 if (data < 0) {
753 dev_err(&client->dev,
754 "Unable to read output control register\n");
755 return -EIO;
756 }
757
758 /*
759 * Write the configuration key register to enable access to
760 * the config2 register
761 */
762 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
763 ABX8XX_CFG_KEY_MISC);
764 if (err < 0) {
765 dev_err(&client->dev,
766 "Unable to write configuration key\n");
767 return -EIO;
768 }
769
770 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
771 data | ABX8XX_OUT_CTRL_EXDS);
772 if (err < 0) {
773 dev_err(&client->dev,
774 "Unable to write output control register\n");
775 return -EIO;
776 }
777 }
778
779 /* part autodetection */
780 if (part == ABX80X) {
781 for (i = 0; abx80x_caps[i].pn; i++)
782 if (partnumber == abx80x_caps[i].pn)
783 break;
784 if (abx80x_caps[i].pn == 0) {
785 dev_err(&client->dev, "Unknown part: %04x\n",
786 partnumber);
787 return -EINVAL;
788 }
789 part = i;
790 }
791
792 if (partnumber != abx80x_caps[part].pn) {
793 dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
794 partnumber, abx80x_caps[part].pn);
795 return -EINVAL;
796 }
797
798 if (np && abx80x_caps[part].has_tc)
799 trickle_cfg = abx80x_dt_trickle_cfg(np);
800
801 if (trickle_cfg > 0) {
802 dev_info(&client->dev, "Enabling trickle charger: %02x\n",
803 trickle_cfg);
804 abx80x_enable_trickle_charger(client, trickle_cfg);
805 }
806
807 err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
808 BIT(2));
809 if (err)
810 return err;
811
812 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
813 if (priv == NULL)
814 return -ENOMEM;
815
816 priv->rtc = devm_rtc_allocate_device(&client->dev);
817 if (IS_ERR(priv->rtc))
818 return PTR_ERR(priv->rtc);
819
820 priv->rtc->ops = &abx80x_rtc_ops;
821 priv->client = client;
822
823 i2c_set_clientdata(client, priv);
824
825 if (abx80x_caps[part].has_wdog) {
826 err = abx80x_setup_watchdog(priv);
827 if (err)
828 return err;
829 }
830
831 if (client->irq > 0) {
832 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
833 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
834 abx80x_handle_irq,
835 IRQF_SHARED | IRQF_ONESHOT,
836 "abx8xx",
837 client);
838 if (err) {
839 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
840 client->irq = 0;
841 }
842 }
843
844 err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
845 if (err) {
846 dev_err(&client->dev, "Failed to create sysfs group: %d\n",
847 err);
848 return err;
849 }
850
851 return rtc_register_device(priv->rtc);
852}
853
854static const struct i2c_device_id abx80x_id[] = {
855 { "abx80x", ABX80X },
856 { "ab0801", AB0801 },
857 { "ab0803", AB0803 },
858 { "ab0804", AB0804 },
859 { "ab0805", AB0805 },
860 { "ab1801", AB1801 },
861 { "ab1803", AB1803 },
862 { "ab1804", AB1804 },
863 { "ab1805", AB1805 },
864 { "rv1805", RV1805 },
865 { }
866};
867MODULE_DEVICE_TABLE(i2c, abx80x_id);
868
869static struct i2c_driver abx80x_driver = {
870 .driver = {
871 .name = "rtc-abx80x",
872 },
873 .probe = abx80x_probe,
874 .id_table = abx80x_id,
875};
876
877module_i2c_driver(abx80x_driver);
878
879MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
880MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
881MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
882MODULE_LICENSE("GPL v2");