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1// SPDX-License-Identifier: GPL-2.0-only
2/* rtc-ds1343.c
3 *
4 * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
5 * Real Time Clock
6 *
7 * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
8 * Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
9 */
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/interrupt.h>
14#include <linux/device.h>
15#include <linux/spi/spi.h>
16#include <linux/regmap.h>
17#include <linux/rtc.h>
18#include <linux/bcd.h>
19#include <linux/pm.h>
20#include <linux/pm_wakeirq.h>
21#include <linux/slab.h>
22
23#define DALLAS_MAXIM_DS1343 0
24#define DALLAS_MAXIM_DS1344 1
25
26/* RTC DS1343 Registers */
27#define DS1343_SECONDS_REG 0x00
28#define DS1343_MINUTES_REG 0x01
29#define DS1343_HOURS_REG 0x02
30#define DS1343_DAY_REG 0x03
31#define DS1343_DATE_REG 0x04
32#define DS1343_MONTH_REG 0x05
33#define DS1343_YEAR_REG 0x06
34#define DS1343_ALM0_SEC_REG 0x07
35#define DS1343_ALM0_MIN_REG 0x08
36#define DS1343_ALM0_HOUR_REG 0x09
37#define DS1343_ALM0_DAY_REG 0x0A
38#define DS1343_ALM1_SEC_REG 0x0B
39#define DS1343_ALM1_MIN_REG 0x0C
40#define DS1343_ALM1_HOUR_REG 0x0D
41#define DS1343_ALM1_DAY_REG 0x0E
42#define DS1343_CONTROL_REG 0x0F
43#define DS1343_STATUS_REG 0x10
44#define DS1343_TRICKLE_REG 0x11
45#define DS1343_NVRAM 0x20
46
47#define DS1343_NVRAM_LEN 96
48
49/* DS1343 Control Registers bits */
50#define DS1343_EOSC 0x80
51#define DS1343_DOSF 0x20
52#define DS1343_EGFIL 0x10
53#define DS1343_SQW 0x08
54#define DS1343_INTCN 0x04
55#define DS1343_A1IE 0x02
56#define DS1343_A0IE 0x01
57
58/* DS1343 Status Registers bits */
59#define DS1343_OSF 0x80
60#define DS1343_IRQF1 0x02
61#define DS1343_IRQF0 0x01
62
63/* DS1343 Trickle Charger Registers bits */
64#define DS1343_TRICKLE_MAGIC 0xa0
65#define DS1343_TRICKLE_DS1 0x08
66#define DS1343_TRICKLE_1K 0x01
67#define DS1343_TRICKLE_2K 0x02
68#define DS1343_TRICKLE_4K 0x03
69
70static const struct spi_device_id ds1343_id[] = {
71 { "ds1343", DALLAS_MAXIM_DS1343 },
72 { "ds1344", DALLAS_MAXIM_DS1344 },
73 { }
74};
75MODULE_DEVICE_TABLE(spi, ds1343_id);
76
77struct ds1343_priv {
78 struct spi_device *spi;
79 struct rtc_device *rtc;
80 struct regmap *map;
81 struct mutex mutex;
82 unsigned int irqen;
83 int irq;
84 int alarm_sec;
85 int alarm_min;
86 int alarm_hour;
87 int alarm_mday;
88};
89
90static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
91{
92 switch (cmd) {
93#ifdef RTC_SET_CHARGE
94 case RTC_SET_CHARGE:
95 {
96 int val;
97
98 if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
99 return -EFAULT;
100
101 return regmap_write(priv->map, DS1343_TRICKLE_REG, val);
102 }
103 break;
104#endif
105 }
106
107 return -ENOIOCTLCMD;
108}
109
110static ssize_t ds1343_show_glitchfilter(struct device *dev,
111 struct device_attribute *attr, char *buf)
112{
113 struct ds1343_priv *priv = dev_get_drvdata(dev);
114 int glitch_filt_status, data;
115
116 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
117
118 glitch_filt_status = !!(data & DS1343_EGFIL);
119
120 if (glitch_filt_status)
121 return sprintf(buf, "enabled\n");
122 else
123 return sprintf(buf, "disabled\n");
124}
125
126static ssize_t ds1343_store_glitchfilter(struct device *dev,
127 struct device_attribute *attr,
128 const char *buf, size_t count)
129{
130 struct ds1343_priv *priv = dev_get_drvdata(dev);
131 int data;
132
133 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
134
135 if (strncmp(buf, "enabled", 7) == 0)
136 data |= DS1343_EGFIL;
137
138 else if (strncmp(buf, "disabled", 8) == 0)
139 data &= ~(DS1343_EGFIL);
140
141 else
142 return -EINVAL;
143
144 regmap_write(priv->map, DS1343_CONTROL_REG, data);
145
146 return count;
147}
148
149static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
150 ds1343_store_glitchfilter);
151
152static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
153 size_t bytes)
154{
155 struct ds1343_priv *ds1343 = priv;
156
157 return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
158}
159
160static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
161 size_t bytes)
162{
163 struct ds1343_priv *ds1343 = priv;
164
165 return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
166}
167
168static ssize_t ds1343_show_tricklecharger(struct device *dev,
169 struct device_attribute *attr, char *buf)
170{
171 struct ds1343_priv *priv = dev_get_drvdata(dev);
172 int data;
173 char *diodes = "disabled", *resistors = " ";
174
175 regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
176
177 if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
178 switch (data & 0x0c) {
179 case DS1343_TRICKLE_DS1:
180 diodes = "one diode,";
181 break;
182
183 default:
184 diodes = "no diode,";
185 break;
186 }
187
188 switch (data & 0x03) {
189 case DS1343_TRICKLE_1K:
190 resistors = "1k Ohm";
191 break;
192
193 case DS1343_TRICKLE_2K:
194 resistors = "2k Ohm";
195 break;
196
197 case DS1343_TRICKLE_4K:
198 resistors = "4k Ohm";
199 break;
200
201 default:
202 diodes = "disabled";
203 break;
204 }
205 }
206
207 return sprintf(buf, "%s %s\n", diodes, resistors);
208}
209
210static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
211
212static int ds1343_sysfs_register(struct device *dev)
213{
214 int err;
215
216 err = device_create_file(dev, &dev_attr_glitch_filter);
217 if (err)
218 return err;
219
220 err = device_create_file(dev, &dev_attr_trickle_charger);
221 if (!err)
222 return 0;
223
224 device_remove_file(dev, &dev_attr_glitch_filter);
225
226 return err;
227}
228
229static void ds1343_sysfs_unregister(struct device *dev)
230{
231 device_remove_file(dev, &dev_attr_glitch_filter);
232 device_remove_file(dev, &dev_attr_trickle_charger);
233}
234
235static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
236{
237 struct ds1343_priv *priv = dev_get_drvdata(dev);
238 unsigned char buf[7];
239 int res;
240
241 res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
242 if (res)
243 return res;
244
245 dt->tm_sec = bcd2bin(buf[0]);
246 dt->tm_min = bcd2bin(buf[1]);
247 dt->tm_hour = bcd2bin(buf[2] & 0x3F);
248 dt->tm_wday = bcd2bin(buf[3]) - 1;
249 dt->tm_mday = bcd2bin(buf[4]);
250 dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1;
251 dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
252
253 return 0;
254}
255
256static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
257{
258 struct ds1343_priv *priv = dev_get_drvdata(dev);
259 int res;
260
261 res = regmap_write(priv->map, DS1343_SECONDS_REG,
262 bin2bcd(dt->tm_sec));
263 if (res)
264 return res;
265
266 res = regmap_write(priv->map, DS1343_MINUTES_REG,
267 bin2bcd(dt->tm_min));
268 if (res)
269 return res;
270
271 res = regmap_write(priv->map, DS1343_HOURS_REG,
272 bin2bcd(dt->tm_hour) & 0x3F);
273 if (res)
274 return res;
275
276 res = regmap_write(priv->map, DS1343_DAY_REG,
277 bin2bcd(dt->tm_wday + 1));
278 if (res)
279 return res;
280
281 res = regmap_write(priv->map, DS1343_DATE_REG,
282 bin2bcd(dt->tm_mday));
283 if (res)
284 return res;
285
286 res = regmap_write(priv->map, DS1343_MONTH_REG,
287 bin2bcd(dt->tm_mon + 1));
288 if (res)
289 return res;
290
291 dt->tm_year %= 100;
292
293 res = regmap_write(priv->map, DS1343_YEAR_REG,
294 bin2bcd(dt->tm_year));
295 if (res)
296 return res;
297
298 return 0;
299}
300
301static int ds1343_update_alarm(struct device *dev)
302{
303 struct ds1343_priv *priv = dev_get_drvdata(dev);
304 unsigned int control, stat;
305 unsigned char buf[4];
306 int res = 0;
307
308 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
309 if (res)
310 return res;
311
312 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
313 if (res)
314 return res;
315
316 control &= ~(DS1343_A0IE);
317 stat &= ~(DS1343_IRQF0);
318
319 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
320 if (res)
321 return res;
322
323 res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
324 if (res)
325 return res;
326
327 buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
328 0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
329 buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
330 0x80 : bin2bcd(priv->alarm_min) & 0x7F;
331 buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
332 0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
333 buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
334 0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
335
336 res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
337 if (res)
338 return res;
339
340 if (priv->irqen) {
341 control |= DS1343_A0IE;
342 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
343 }
344
345 return res;
346}
347
348static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
349{
350 struct ds1343_priv *priv = dev_get_drvdata(dev);
351 int res = 0;
352 unsigned int stat;
353
354 if (priv->irq <= 0)
355 return -EINVAL;
356
357 mutex_lock(&priv->mutex);
358
359 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
360 if (res)
361 goto out;
362
363 alarm->enabled = !!(priv->irqen & RTC_AF);
364 alarm->pending = !!(stat & DS1343_IRQF0);
365
366 alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
367 alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
368 alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
369 alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
370
371out:
372 mutex_unlock(&priv->mutex);
373 return res;
374}
375
376static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
377{
378 struct ds1343_priv *priv = dev_get_drvdata(dev);
379 int res = 0;
380
381 if (priv->irq <= 0)
382 return -EINVAL;
383
384 mutex_lock(&priv->mutex);
385
386 priv->alarm_sec = alarm->time.tm_sec;
387 priv->alarm_min = alarm->time.tm_min;
388 priv->alarm_hour = alarm->time.tm_hour;
389 priv->alarm_mday = alarm->time.tm_mday;
390
391 if (alarm->enabled)
392 priv->irqen |= RTC_AF;
393
394 res = ds1343_update_alarm(dev);
395
396 mutex_unlock(&priv->mutex);
397
398 return res;
399}
400
401static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
402{
403 struct ds1343_priv *priv = dev_get_drvdata(dev);
404 int res = 0;
405
406 if (priv->irq <= 0)
407 return -EINVAL;
408
409 mutex_lock(&priv->mutex);
410
411 if (enabled)
412 priv->irqen |= RTC_AF;
413 else
414 priv->irqen &= ~RTC_AF;
415
416 res = ds1343_update_alarm(dev);
417
418 mutex_unlock(&priv->mutex);
419
420 return res;
421}
422
423static irqreturn_t ds1343_thread(int irq, void *dev_id)
424{
425 struct ds1343_priv *priv = dev_id;
426 unsigned int stat, control;
427 int res = 0;
428
429 mutex_lock(&priv->mutex);
430
431 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
432 if (res)
433 goto out;
434
435 if (stat & DS1343_IRQF0) {
436 stat &= ~DS1343_IRQF0;
437 regmap_write(priv->map, DS1343_STATUS_REG, stat);
438
439 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
440 if (res)
441 goto out;
442
443 control &= ~DS1343_A0IE;
444 regmap_write(priv->map, DS1343_CONTROL_REG, control);
445
446 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
447 }
448
449out:
450 mutex_unlock(&priv->mutex);
451 return IRQ_HANDLED;
452}
453
454static const struct rtc_class_ops ds1343_rtc_ops = {
455 .ioctl = ds1343_ioctl,
456 .read_time = ds1343_read_time,
457 .set_time = ds1343_set_time,
458 .read_alarm = ds1343_read_alarm,
459 .set_alarm = ds1343_set_alarm,
460 .alarm_irq_enable = ds1343_alarm_irq_enable,
461};
462
463static int ds1343_probe(struct spi_device *spi)
464{
465 struct ds1343_priv *priv;
466 struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
467 .write_flag_mask = 0x80, };
468 unsigned int data;
469 int res;
470 struct nvmem_config nvmem_cfg = {
471 .name = "ds1343-",
472 .word_size = 1,
473 .stride = 1,
474 .size = DS1343_NVRAM_LEN,
475 .reg_read = ds1343_nvram_read,
476 .reg_write = ds1343_nvram_write,
477 };
478
479 priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
480 if (!priv)
481 return -ENOMEM;
482
483 priv->spi = spi;
484 mutex_init(&priv->mutex);
485
486 /* RTC DS1347 works in spi mode 3 and
487 * its chip select is active high
488 */
489 spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
490 spi->bits_per_word = 8;
491 res = spi_setup(spi);
492 if (res)
493 return res;
494
495 spi_set_drvdata(spi, priv);
496
497 priv->map = devm_regmap_init_spi(spi, &config);
498
499 if (IS_ERR(priv->map)) {
500 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
501 return PTR_ERR(priv->map);
502 }
503
504 res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
505 if (res)
506 return res;
507
508 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
509 data |= DS1343_INTCN;
510 data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
511 regmap_write(priv->map, DS1343_CONTROL_REG, data);
512
513 regmap_read(priv->map, DS1343_STATUS_REG, &data);
514 data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
515 regmap_write(priv->map, DS1343_STATUS_REG, data);
516
517 priv->rtc = devm_rtc_allocate_device(&spi->dev);
518 if (IS_ERR(priv->rtc))
519 return PTR_ERR(priv->rtc);
520
521 priv->rtc->nvram_old_abi = true;
522 priv->rtc->ops = &ds1343_rtc_ops;
523
524 res = rtc_register_device(priv->rtc);
525 if (res)
526 return res;
527
528 nvmem_cfg.priv = priv;
529 rtc_nvmem_register(priv->rtc, &nvmem_cfg);
530
531 priv->irq = spi->irq;
532
533 if (priv->irq >= 0) {
534 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
535 ds1343_thread, IRQF_ONESHOT,
536 "ds1343", priv);
537 if (res) {
538 priv->irq = -1;
539 dev_err(&spi->dev,
540 "unable to request irq for rtc ds1343\n");
541 } else {
542 device_init_wakeup(&spi->dev, true);
543 dev_pm_set_wake_irq(&spi->dev, spi->irq);
544 }
545 }
546
547 res = ds1343_sysfs_register(&spi->dev);
548 if (res)
549 dev_err(&spi->dev,
550 "unable to create sysfs entries for rtc ds1343\n");
551
552 return 0;
553}
554
555static int ds1343_remove(struct spi_device *spi)
556{
557 struct ds1343_priv *priv = spi_get_drvdata(spi);
558
559 if (spi->irq) {
560 mutex_lock(&priv->mutex);
561 priv->irqen &= ~RTC_AF;
562 mutex_unlock(&priv->mutex);
563
564 dev_pm_clear_wake_irq(&spi->dev);
565 device_init_wakeup(&spi->dev, false);
566 devm_free_irq(&spi->dev, spi->irq, priv);
567 }
568
569 spi_set_drvdata(spi, NULL);
570
571 ds1343_sysfs_unregister(&spi->dev);
572
573 return 0;
574}
575
576#ifdef CONFIG_PM_SLEEP
577
578static int ds1343_suspend(struct device *dev)
579{
580 struct spi_device *spi = to_spi_device(dev);
581
582 if (spi->irq >= 0 && device_may_wakeup(dev))
583 enable_irq_wake(spi->irq);
584
585 return 0;
586}
587
588static int ds1343_resume(struct device *dev)
589{
590 struct spi_device *spi = to_spi_device(dev);
591
592 if (spi->irq >= 0 && device_may_wakeup(dev))
593 disable_irq_wake(spi->irq);
594
595 return 0;
596}
597
598#endif
599
600static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
601
602static struct spi_driver ds1343_driver = {
603 .driver = {
604 .name = "ds1343",
605 .pm = &ds1343_pm,
606 },
607 .probe = ds1343_probe,
608 .remove = ds1343_remove,
609 .id_table = ds1343_id,
610};
611
612module_spi_driver(ds1343_driver);
613
614MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
615MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
616 "Ankur Srivastava <sankurece@gmail.com>");
617MODULE_LICENSE("GPL v2");