1 /* rtc-ds1343.c
2 *
3 * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
4 * Real Time Clock
5 *
6 * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
7 * Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 */
14
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/device.h>
19 #include <linux/spi/spi.h>
20 #include <linux/regmap.h>
21 #include <linux/rtc.h>
22 #include <linux/bcd.h>
23 #include <linux/pm.h>
24 #include <linux/pm_wakeirq.h>
25 #include <linux/slab.h>
26
27 #define DALLAS_MAXIM_DS1343 0
28 #define DALLAS_MAXIM_DS1344 1
29
30 /* RTC DS1343 Registers */
31 #define DS1343_SECONDS_REG 0x00
32 #define DS1343_MINUTES_REG 0x01
33 #define DS1343_HOURS_REG 0x02
34 #define DS1343_DAY_REG 0x03
35 #define DS1343_DATE_REG 0x04
36 #define DS1343_MONTH_REG 0x05
37 #define DS1343_YEAR_REG 0x06
38 #define DS1343_ALM0_SEC_REG 0x07
39 #define DS1343_ALM0_MIN_REG 0x08
40 #define DS1343_ALM0_HOUR_REG 0x09
41 #define DS1343_ALM0_DAY_REG 0x0A
42 #define DS1343_ALM1_SEC_REG 0x0B
43 #define DS1343_ALM1_MIN_REG 0x0C
44 #define DS1343_ALM1_HOUR_REG 0x0D
45 #define DS1343_ALM1_DAY_REG 0x0E
46 #define DS1343_CONTROL_REG 0x0F
47 #define DS1343_STATUS_REG 0x10
48 #define DS1343_TRICKLE_REG 0x11
49 #define DS1343_NVRAM 0x20
50
51 #define DS1343_NVRAM_LEN 96
52
53 /* DS1343 Control Registers bits */
54 #define DS1343_EOSC 0x80
55 #define DS1343_DOSF 0x20
56 #define DS1343_EGFIL 0x10
57 #define DS1343_SQW 0x08
58 #define DS1343_INTCN 0x04
59 #define DS1343_A1IE 0x02
60 #define DS1343_A0IE 0x01
61
62 /* DS1343 Status Registers bits */
63 #define DS1343_OSF 0x80
64 #define DS1343_IRQF1 0x02
65 #define DS1343_IRQF0 0x01
66
67 /* DS1343 Trickle Charger Registers bits */
68 #define DS1343_TRICKLE_MAGIC 0xa0
69 #define DS1343_TRICKLE_DS1 0x08
70 #define DS1343_TRICKLE_1K 0x01
71 #define DS1343_TRICKLE_2K 0x02
72 #define DS1343_TRICKLE_4K 0x03
73
74 static const struct spi_device_id ds1343_id[] = {
75 { "ds1343", DALLAS_MAXIM_DS1343 },
76 { "ds1344", DALLAS_MAXIM_DS1344 },
77 { }
78 };
79 MODULE_DEVICE_TABLE(spi, ds1343_id);
80
81 struct ds1343_priv {
82 struct spi_device *spi;
83 struct rtc_device *rtc;
84 struct regmap *map;
85 struct mutex mutex;
86 unsigned int irqen;
87 int irq;
88 int alarm_sec;
89 int alarm_min;
90 int alarm_hour;
91 int alarm_mday;
92 };
93
ds1343_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)94 static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
95 {
96 switch (cmd) {
97 #ifdef RTC_SET_CHARGE
98 case RTC_SET_CHARGE:
99 {
100 int val;
101
102 if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
103 return -EFAULT;
104
105 return regmap_write(priv->map, DS1343_TRICKLE_REG, val);
106 }
107 break;
108 #endif
109 }
110
111 return -ENOIOCTLCMD;
112 }
113
ds1343_show_glitchfilter(struct device * dev,struct device_attribute * attr,char * buf)114 static ssize_t ds1343_show_glitchfilter(struct device *dev,
115 struct device_attribute *attr, char *buf)
116 {
117 struct ds1343_priv *priv = dev_get_drvdata(dev);
118 int glitch_filt_status, data;
119
120 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
121
122 glitch_filt_status = !!(data & DS1343_EGFIL);
123
124 if (glitch_filt_status)
125 return sprintf(buf, "enabled\n");
126 else
127 return sprintf(buf, "disabled\n");
128 }
129
ds1343_store_glitchfilter(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)130 static ssize_t ds1343_store_glitchfilter(struct device *dev,
131 struct device_attribute *attr,
132 const char *buf, size_t count)
133 {
134 struct ds1343_priv *priv = dev_get_drvdata(dev);
135 int data;
136
137 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
138
139 if (strncmp(buf, "enabled", 7) == 0)
140 data |= DS1343_EGFIL;
141
142 else if (strncmp(buf, "disabled", 8) == 0)
143 data &= ~(DS1343_EGFIL);
144
145 else
146 return -EINVAL;
147
148 regmap_write(priv->map, DS1343_CONTROL_REG, data);
149
150 return count;
151 }
152
153 static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
154 ds1343_store_glitchfilter);
155
ds1343_nvram_write(void * priv,unsigned int off,void * val,size_t bytes)156 static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
157 size_t bytes)
158 {
159 struct ds1343_priv *ds1343 = priv;
160
161 return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
162 }
163
ds1343_nvram_read(void * priv,unsigned int off,void * val,size_t bytes)164 static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
165 size_t bytes)
166 {
167 struct ds1343_priv *ds1343 = priv;
168
169 return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
170 }
171
ds1343_show_tricklecharger(struct device * dev,struct device_attribute * attr,char * buf)172 static ssize_t ds1343_show_tricklecharger(struct device *dev,
173 struct device_attribute *attr, char *buf)
174 {
175 struct ds1343_priv *priv = dev_get_drvdata(dev);
176 int data;
177 char *diodes = "disabled", *resistors = " ";
178
179 regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
180
181 if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
182 switch (data & 0x0c) {
183 case DS1343_TRICKLE_DS1:
184 diodes = "one diode,";
185 break;
186
187 default:
188 diodes = "no diode,";
189 break;
190 }
191
192 switch (data & 0x03) {
193 case DS1343_TRICKLE_1K:
194 resistors = "1k Ohm";
195 break;
196
197 case DS1343_TRICKLE_2K:
198 resistors = "2k Ohm";
199 break;
200
201 case DS1343_TRICKLE_4K:
202 resistors = "4k Ohm";
203 break;
204
205 default:
206 diodes = "disabled";
207 break;
208 }
209 }
210
211 return sprintf(buf, "%s %s\n", diodes, resistors);
212 }
213
214 static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
215
ds1343_sysfs_register(struct device * dev)216 static int ds1343_sysfs_register(struct device *dev)
217 {
218 int err;
219
220 err = device_create_file(dev, &dev_attr_glitch_filter);
221 if (err)
222 return err;
223
224 err = device_create_file(dev, &dev_attr_trickle_charger);
225 if (!err)
226 return 0;
227
228 device_remove_file(dev, &dev_attr_glitch_filter);
229
230 return err;
231 }
232
ds1343_sysfs_unregister(struct device * dev)233 static void ds1343_sysfs_unregister(struct device *dev)
234 {
235 device_remove_file(dev, &dev_attr_glitch_filter);
236 device_remove_file(dev, &dev_attr_trickle_charger);
237 }
238
ds1343_read_time(struct device * dev,struct rtc_time * dt)239 static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
240 {
241 struct ds1343_priv *priv = dev_get_drvdata(dev);
242 unsigned char buf[7];
243 int res;
244
245 res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
246 if (res)
247 return res;
248
249 dt->tm_sec = bcd2bin(buf[0]);
250 dt->tm_min = bcd2bin(buf[1]);
251 dt->tm_hour = bcd2bin(buf[2] & 0x3F);
252 dt->tm_wday = bcd2bin(buf[3]) - 1;
253 dt->tm_mday = bcd2bin(buf[4]);
254 dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1;
255 dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
256
257 return 0;
258 }
259
ds1343_set_time(struct device * dev,struct rtc_time * dt)260 static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
261 {
262 struct ds1343_priv *priv = dev_get_drvdata(dev);
263 int res;
264
265 res = regmap_write(priv->map, DS1343_SECONDS_REG,
266 bin2bcd(dt->tm_sec));
267 if (res)
268 return res;
269
270 res = regmap_write(priv->map, DS1343_MINUTES_REG,
271 bin2bcd(dt->tm_min));
272 if (res)
273 return res;
274
275 res = regmap_write(priv->map, DS1343_HOURS_REG,
276 bin2bcd(dt->tm_hour) & 0x3F);
277 if (res)
278 return res;
279
280 res = regmap_write(priv->map, DS1343_DAY_REG,
281 bin2bcd(dt->tm_wday + 1));
282 if (res)
283 return res;
284
285 res = regmap_write(priv->map, DS1343_DATE_REG,
286 bin2bcd(dt->tm_mday));
287 if (res)
288 return res;
289
290 res = regmap_write(priv->map, DS1343_MONTH_REG,
291 bin2bcd(dt->tm_mon + 1));
292 if (res)
293 return res;
294
295 dt->tm_year %= 100;
296
297 res = regmap_write(priv->map, DS1343_YEAR_REG,
298 bin2bcd(dt->tm_year));
299 if (res)
300 return res;
301
302 return 0;
303 }
304
ds1343_update_alarm(struct device * dev)305 static int ds1343_update_alarm(struct device *dev)
306 {
307 struct ds1343_priv *priv = dev_get_drvdata(dev);
308 unsigned int control, stat;
309 unsigned char buf[4];
310 int res = 0;
311
312 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
313 if (res)
314 return res;
315
316 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
317 if (res)
318 return res;
319
320 control &= ~(DS1343_A0IE);
321 stat &= ~(DS1343_IRQF0);
322
323 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
324 if (res)
325 return res;
326
327 res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
328 if (res)
329 return res;
330
331 buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
332 0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
333 buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
334 0x80 : bin2bcd(priv->alarm_min) & 0x7F;
335 buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
336 0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
337 buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
338 0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
339
340 res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
341 if (res)
342 return res;
343
344 if (priv->irqen) {
345 control |= DS1343_A0IE;
346 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
347 }
348
349 return res;
350 }
351
ds1343_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)352 static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
353 {
354 struct ds1343_priv *priv = dev_get_drvdata(dev);
355 int res = 0;
356 unsigned int stat;
357
358 if (priv->irq <= 0)
359 return -EINVAL;
360
361 mutex_lock(&priv->mutex);
362
363 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
364 if (res)
365 goto out;
366
367 alarm->enabled = !!(priv->irqen & RTC_AF);
368 alarm->pending = !!(stat & DS1343_IRQF0);
369
370 alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
371 alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
372 alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
373 alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
374
375 out:
376 mutex_unlock(&priv->mutex);
377 return res;
378 }
379
ds1343_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)380 static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
381 {
382 struct ds1343_priv *priv = dev_get_drvdata(dev);
383 int res = 0;
384
385 if (priv->irq <= 0)
386 return -EINVAL;
387
388 mutex_lock(&priv->mutex);
389
390 priv->alarm_sec = alarm->time.tm_sec;
391 priv->alarm_min = alarm->time.tm_min;
392 priv->alarm_hour = alarm->time.tm_hour;
393 priv->alarm_mday = alarm->time.tm_mday;
394
395 if (alarm->enabled)
396 priv->irqen |= RTC_AF;
397
398 res = ds1343_update_alarm(dev);
399
400 mutex_unlock(&priv->mutex);
401
402 return res;
403 }
404
ds1343_alarm_irq_enable(struct device * dev,unsigned int enabled)405 static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
406 {
407 struct ds1343_priv *priv = dev_get_drvdata(dev);
408 int res = 0;
409
410 if (priv->irq <= 0)
411 return -EINVAL;
412
413 mutex_lock(&priv->mutex);
414
415 if (enabled)
416 priv->irqen |= RTC_AF;
417 else
418 priv->irqen &= ~RTC_AF;
419
420 res = ds1343_update_alarm(dev);
421
422 mutex_unlock(&priv->mutex);
423
424 return res;
425 }
426
ds1343_thread(int irq,void * dev_id)427 static irqreturn_t ds1343_thread(int irq, void *dev_id)
428 {
429 struct ds1343_priv *priv = dev_id;
430 unsigned int stat, control;
431 int res = 0;
432
433 mutex_lock(&priv->mutex);
434
435 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
436 if (res)
437 goto out;
438
439 if (stat & DS1343_IRQF0) {
440 stat &= ~DS1343_IRQF0;
441 regmap_write(priv->map, DS1343_STATUS_REG, stat);
442
443 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
444 if (res)
445 goto out;
446
447 control &= ~DS1343_A0IE;
448 regmap_write(priv->map, DS1343_CONTROL_REG, control);
449
450 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
451 }
452
453 out:
454 mutex_unlock(&priv->mutex);
455 return IRQ_HANDLED;
456 }
457
458 static const struct rtc_class_ops ds1343_rtc_ops = {
459 .ioctl = ds1343_ioctl,
460 .read_time = ds1343_read_time,
461 .set_time = ds1343_set_time,
462 .read_alarm = ds1343_read_alarm,
463 .set_alarm = ds1343_set_alarm,
464 .alarm_irq_enable = ds1343_alarm_irq_enable,
465 };
466
ds1343_probe(struct spi_device * spi)467 static int ds1343_probe(struct spi_device *spi)
468 {
469 struct ds1343_priv *priv;
470 struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
471 .write_flag_mask = 0x80, };
472 unsigned int data;
473 int res;
474 struct nvmem_config nvmem_cfg = {
475 .name = "ds1343-",
476 .word_size = 1,
477 .stride = 1,
478 .size = DS1343_NVRAM_LEN,
479 .reg_read = ds1343_nvram_read,
480 .reg_write = ds1343_nvram_write,
481 };
482
483 priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
484 if (!priv)
485 return -ENOMEM;
486
487 priv->spi = spi;
488 mutex_init(&priv->mutex);
489
490 /* RTC DS1347 works in spi mode 3 and
491 * its chip select is active high
492 */
493 spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
494 spi->bits_per_word = 8;
495 res = spi_setup(spi);
496 if (res)
497 return res;
498
499 spi_set_drvdata(spi, priv);
500
501 priv->map = devm_regmap_init_spi(spi, &config);
502
503 if (IS_ERR(priv->map)) {
504 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
505 return PTR_ERR(priv->map);
506 }
507
508 res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
509 if (res)
510 return res;
511
512 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
513 data |= DS1343_INTCN;
514 data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
515 regmap_write(priv->map, DS1343_CONTROL_REG, data);
516
517 regmap_read(priv->map, DS1343_STATUS_REG, &data);
518 data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
519 regmap_write(priv->map, DS1343_STATUS_REG, data);
520
521 priv->rtc = devm_rtc_allocate_device(&spi->dev);
522 if (IS_ERR(priv->rtc))
523 return PTR_ERR(priv->rtc);
524
525 priv->rtc->nvram_old_abi = true;
526 priv->rtc->ops = &ds1343_rtc_ops;
527
528 res = rtc_register_device(priv->rtc);
529 if (res)
530 return res;
531
532 nvmem_cfg.priv = priv;
533 rtc_nvmem_register(priv->rtc, &nvmem_cfg);
534
535 priv->irq = spi->irq;
536
537 if (priv->irq >= 0) {
538 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
539 ds1343_thread, IRQF_ONESHOT,
540 "ds1343", priv);
541 if (res) {
542 priv->irq = -1;
543 dev_err(&spi->dev,
544 "unable to request irq for rtc ds1343\n");
545 } else {
546 device_init_wakeup(&spi->dev, true);
547 dev_pm_set_wake_irq(&spi->dev, spi->irq);
548 }
549 }
550
551 res = ds1343_sysfs_register(&spi->dev);
552 if (res)
553 dev_err(&spi->dev,
554 "unable to create sysfs entries for rtc ds1343\n");
555
556 return 0;
557 }
558
ds1343_remove(struct spi_device * spi)559 static int ds1343_remove(struct spi_device *spi)
560 {
561 struct ds1343_priv *priv = spi_get_drvdata(spi);
562
563 if (spi->irq) {
564 mutex_lock(&priv->mutex);
565 priv->irqen &= ~RTC_AF;
566 mutex_unlock(&priv->mutex);
567
568 dev_pm_clear_wake_irq(&spi->dev);
569 device_init_wakeup(&spi->dev, false);
570 devm_free_irq(&spi->dev, spi->irq, priv);
571 }
572
573 spi_set_drvdata(spi, NULL);
574
575 ds1343_sysfs_unregister(&spi->dev);
576
577 return 0;
578 }
579
580 #ifdef CONFIG_PM_SLEEP
581
ds1343_suspend(struct device * dev)582 static int ds1343_suspend(struct device *dev)
583 {
584 struct spi_device *spi = to_spi_device(dev);
585
586 if (spi->irq >= 0 && device_may_wakeup(dev))
587 enable_irq_wake(spi->irq);
588
589 return 0;
590 }
591
ds1343_resume(struct device * dev)592 static int ds1343_resume(struct device *dev)
593 {
594 struct spi_device *spi = to_spi_device(dev);
595
596 if (spi->irq >= 0 && device_may_wakeup(dev))
597 disable_irq_wake(spi->irq);
598
599 return 0;
600 }
601
602 #endif
603
604 static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
605
606 static struct spi_driver ds1343_driver = {
607 .driver = {
608 .name = "ds1343",
609 .pm = &ds1343_pm,
610 },
611 .probe = ds1343_probe,
612 .remove = ds1343_remove,
613 .id_table = ds1343_id,
614 };
615
616 module_spi_driver(ds1343_driver);
617
618 MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
619 MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
620 "Ankur Srivastava <sankurece@gmail.com>");
621 MODULE_LICENSE("GPL v2");
622