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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 DS1343_DRV_VERSION "01.00"
28#define DALLAS_MAXIM_DS1343 0
29#define DALLAS_MAXIM_DS1344 1
30
31/* RTC DS1343 Registers */
32#define DS1343_SECONDS_REG 0x00
33#define DS1343_MINUTES_REG 0x01
34#define DS1343_HOURS_REG 0x02
35#define DS1343_DAY_REG 0x03
36#define DS1343_DATE_REG 0x04
37#define DS1343_MONTH_REG 0x05
38#define DS1343_YEAR_REG 0x06
39#define DS1343_ALM0_SEC_REG 0x07
40#define DS1343_ALM0_MIN_REG 0x08
41#define DS1343_ALM0_HOUR_REG 0x09
42#define DS1343_ALM0_DAY_REG 0x0A
43#define DS1343_ALM1_SEC_REG 0x0B
44#define DS1343_ALM1_MIN_REG 0x0C
45#define DS1343_ALM1_HOUR_REG 0x0D
46#define DS1343_ALM1_DAY_REG 0x0E
47#define DS1343_CONTROL_REG 0x0F
48#define DS1343_STATUS_REG 0x10
49#define DS1343_TRICKLE_REG 0x11
50#define DS1343_NVRAM 0x20
51
52#define DS1343_NVRAM_LEN 96
53
54/* DS1343 Control Registers bits */
55#define DS1343_EOSC 0x80
56#define DS1343_DOSF 0x20
57#define DS1343_EGFIL 0x10
58#define DS1343_SQW 0x08
59#define DS1343_INTCN 0x04
60#define DS1343_A1IE 0x02
61#define DS1343_A0IE 0x01
62
63/* DS1343 Status Registers bits */
64#define DS1343_OSF 0x80
65#define DS1343_IRQF1 0x02
66#define DS1343_IRQF0 0x01
67
68/* DS1343 Trickle Charger Registers bits */
69#define DS1343_TRICKLE_MAGIC 0xa0
70#define DS1343_TRICKLE_DS1 0x08
71#define DS1343_TRICKLE_1K 0x01
72#define DS1343_TRICKLE_2K 0x02
73#define DS1343_TRICKLE_4K 0x03
74
75static const struct spi_device_id ds1343_id[] = {
76 { "ds1343", DALLAS_MAXIM_DS1343 },
77 { "ds1344", DALLAS_MAXIM_DS1344 },
78 { }
79};
80MODULE_DEVICE_TABLE(spi, ds1343_id);
81
82struct ds1343_priv {
83 struct spi_device *spi;
84 struct rtc_device *rtc;
85 struct regmap *map;
86 struct mutex mutex;
87 unsigned int irqen;
88 int irq;
89 int alarm_sec;
90 int alarm_min;
91 int alarm_hour;
92 int alarm_mday;
93};
94
95static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
96{
97 switch (cmd) {
98#ifdef RTC_SET_CHARGE
99 case RTC_SET_CHARGE:
100 {
101 int val;
102
103 if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
104 return -EFAULT;
105
106 return regmap_write(priv->map, DS1343_TRICKLE_REG, val);
107 }
108 break;
109#endif
110 }
111
112 return -ENOIOCTLCMD;
113}
114
115static ssize_t ds1343_show_glitchfilter(struct device *dev,
116 struct device_attribute *attr, char *buf)
117{
118 struct ds1343_priv *priv = dev_get_drvdata(dev);
119 int glitch_filt_status, data;
120
121 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
122
123 glitch_filt_status = !!(data & DS1343_EGFIL);
124
125 if (glitch_filt_status)
126 return sprintf(buf, "enabled\n");
127 else
128 return sprintf(buf, "disabled\n");
129}
130
131static ssize_t ds1343_store_glitchfilter(struct device *dev,
132 struct device_attribute *attr,
133 const char *buf, size_t count)
134{
135 struct ds1343_priv *priv = dev_get_drvdata(dev);
136 int data;
137
138 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
139
140 if (strncmp(buf, "enabled", 7) == 0)
141 data |= DS1343_EGFIL;
142
143 else if (strncmp(buf, "disabled", 8) == 0)
144 data &= ~(DS1343_EGFIL);
145
146 else
147 return -EINVAL;
148
149 regmap_write(priv->map, DS1343_CONTROL_REG, data);
150
151 return count;
152}
153
154static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
155 ds1343_store_glitchfilter);
156
157static ssize_t ds1343_nvram_write(struct file *filp, struct kobject *kobj,
158 struct bin_attribute *attr,
159 char *buf, loff_t off, size_t count)
160{
161 int ret;
162 unsigned char address;
163 struct device *dev = kobj_to_dev(kobj);
164 struct ds1343_priv *priv = dev_get_drvdata(dev);
165
166 address = DS1343_NVRAM + off;
167
168 ret = regmap_bulk_write(priv->map, address, buf, count);
169 if (ret < 0)
170 dev_err(&priv->spi->dev, "Error in nvram write %d", ret);
171
172 return (ret < 0) ? ret : count;
173}
174
175
176static ssize_t ds1343_nvram_read(struct file *filp, struct kobject *kobj,
177 struct bin_attribute *attr,
178 char *buf, loff_t off, size_t count)
179{
180 int ret;
181 unsigned char address;
182 struct device *dev = kobj_to_dev(kobj);
183 struct ds1343_priv *priv = dev_get_drvdata(dev);
184
185 address = DS1343_NVRAM + off;
186
187 ret = regmap_bulk_read(priv->map, address, buf, count);
188 if (ret < 0)
189 dev_err(&priv->spi->dev, "Error in nvram read %d\n", ret);
190
191 return (ret < 0) ? ret : count;
192}
193
194
195static struct bin_attribute nvram_attr = {
196 .attr.name = "nvram",
197 .attr.mode = S_IRUGO | S_IWUSR,
198 .read = ds1343_nvram_read,
199 .write = ds1343_nvram_write,
200 .size = DS1343_NVRAM_LEN,
201};
202
203static ssize_t ds1343_show_alarmstatus(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct ds1343_priv *priv = dev_get_drvdata(dev);
207 int alarmstatus, data;
208
209 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
210
211 alarmstatus = !!(data & DS1343_A0IE);
212
213 if (alarmstatus)
214 return sprintf(buf, "enabled\n");
215 else
216 return sprintf(buf, "disabled\n");
217}
218
219static DEVICE_ATTR(alarm_status, S_IRUGO, ds1343_show_alarmstatus, NULL);
220
221static ssize_t ds1343_show_alarmmode(struct device *dev,
222 struct device_attribute *attr, char *buf)
223{
224 struct ds1343_priv *priv = dev_get_drvdata(dev);
225 int alarm_mode, data;
226 char *alarm_str;
227
228 regmap_read(priv->map, DS1343_ALM0_SEC_REG, &data);
229 alarm_mode = (data & 0x80) >> 4;
230
231 regmap_read(priv->map, DS1343_ALM0_MIN_REG, &data);
232 alarm_mode |= (data & 0x80) >> 5;
233
234 regmap_read(priv->map, DS1343_ALM0_HOUR_REG, &data);
235 alarm_mode |= (data & 0x80) >> 6;
236
237 regmap_read(priv->map, DS1343_ALM0_DAY_REG, &data);
238 alarm_mode |= (data & 0x80) >> 7;
239
240 switch (alarm_mode) {
241 case 15:
242 alarm_str = "each second";
243 break;
244
245 case 7:
246 alarm_str = "seconds match";
247 break;
248
249 case 3:
250 alarm_str = "minutes and seconds match";
251 break;
252
253 case 1:
254 alarm_str = "hours, minutes and seconds match";
255 break;
256
257 case 0:
258 alarm_str = "day, hours, minutes and seconds match";
259 break;
260
261 default:
262 alarm_str = "invalid";
263 break;
264 }
265
266 return sprintf(buf, "%s\n", alarm_str);
267}
268
269static DEVICE_ATTR(alarm_mode, S_IRUGO, ds1343_show_alarmmode, NULL);
270
271static ssize_t ds1343_show_tricklecharger(struct device *dev,
272 struct device_attribute *attr, char *buf)
273{
274 struct ds1343_priv *priv = dev_get_drvdata(dev);
275 int data;
276 char *diodes = "disabled", *resistors = " ";
277
278 regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
279
280 if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
281 switch (data & 0x0c) {
282 case DS1343_TRICKLE_DS1:
283 diodes = "one diode,";
284 break;
285
286 default:
287 diodes = "no diode,";
288 break;
289 }
290
291 switch (data & 0x03) {
292 case DS1343_TRICKLE_1K:
293 resistors = "1k Ohm";
294 break;
295
296 case DS1343_TRICKLE_2K:
297 resistors = "2k Ohm";
298 break;
299
300 case DS1343_TRICKLE_4K:
301 resistors = "4k Ohm";
302 break;
303
304 default:
305 diodes = "disabled";
306 break;
307 }
308 }
309
310 return sprintf(buf, "%s %s\n", diodes, resistors);
311}
312
313static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
314
315static int ds1343_sysfs_register(struct device *dev)
316{
317 struct ds1343_priv *priv = dev_get_drvdata(dev);
318 int err;
319
320 err = device_create_file(dev, &dev_attr_glitch_filter);
321 if (err)
322 return err;
323
324 err = device_create_file(dev, &dev_attr_trickle_charger);
325 if (err)
326 goto error1;
327
328 err = device_create_bin_file(dev, &nvram_attr);
329 if (err)
330 goto error2;
331
332 if (priv->irq <= 0)
333 return err;
334
335 err = device_create_file(dev, &dev_attr_alarm_mode);
336 if (err)
337 goto error3;
338
339 err = device_create_file(dev, &dev_attr_alarm_status);
340 if (!err)
341 return err;
342
343 device_remove_file(dev, &dev_attr_alarm_mode);
344
345error3:
346 device_remove_bin_file(dev, &nvram_attr);
347
348error2:
349 device_remove_file(dev, &dev_attr_trickle_charger);
350
351error1:
352 device_remove_file(dev, &dev_attr_glitch_filter);
353
354 return err;
355}
356
357static void ds1343_sysfs_unregister(struct device *dev)
358{
359 struct ds1343_priv *priv = dev_get_drvdata(dev);
360
361 device_remove_file(dev, &dev_attr_glitch_filter);
362 device_remove_file(dev, &dev_attr_trickle_charger);
363 device_remove_bin_file(dev, &nvram_attr);
364
365 if (priv->irq <= 0)
366 return;
367
368 device_remove_file(dev, &dev_attr_alarm_status);
369 device_remove_file(dev, &dev_attr_alarm_mode);
370}
371
372static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
373{
374 struct ds1343_priv *priv = dev_get_drvdata(dev);
375 unsigned char buf[7];
376 int res;
377
378 res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
379 if (res)
380 return res;
381
382 dt->tm_sec = bcd2bin(buf[0]);
383 dt->tm_min = bcd2bin(buf[1]);
384 dt->tm_hour = bcd2bin(buf[2] & 0x3F);
385 dt->tm_wday = bcd2bin(buf[3]) - 1;
386 dt->tm_mday = bcd2bin(buf[4]);
387 dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1;
388 dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
389
390 return rtc_valid_tm(dt);
391}
392
393static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
394{
395 struct ds1343_priv *priv = dev_get_drvdata(dev);
396 int res;
397
398 res = regmap_write(priv->map, DS1343_SECONDS_REG,
399 bin2bcd(dt->tm_sec));
400 if (res)
401 return res;
402
403 res = regmap_write(priv->map, DS1343_MINUTES_REG,
404 bin2bcd(dt->tm_min));
405 if (res)
406 return res;
407
408 res = regmap_write(priv->map, DS1343_HOURS_REG,
409 bin2bcd(dt->tm_hour) & 0x3F);
410 if (res)
411 return res;
412
413 res = regmap_write(priv->map, DS1343_DAY_REG,
414 bin2bcd(dt->tm_wday + 1));
415 if (res)
416 return res;
417
418 res = regmap_write(priv->map, DS1343_DATE_REG,
419 bin2bcd(dt->tm_mday));
420 if (res)
421 return res;
422
423 res = regmap_write(priv->map, DS1343_MONTH_REG,
424 bin2bcd(dt->tm_mon + 1));
425 if (res)
426 return res;
427
428 dt->tm_year %= 100;
429
430 res = regmap_write(priv->map, DS1343_YEAR_REG,
431 bin2bcd(dt->tm_year));
432 if (res)
433 return res;
434
435 return 0;
436}
437
438static int ds1343_update_alarm(struct device *dev)
439{
440 struct ds1343_priv *priv = dev_get_drvdata(dev);
441 unsigned int control, stat;
442 unsigned char buf[4];
443 int res = 0;
444
445 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
446 if (res)
447 return res;
448
449 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
450 if (res)
451 return res;
452
453 control &= ~(DS1343_A0IE);
454 stat &= ~(DS1343_IRQF0);
455
456 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
457 if (res)
458 return res;
459
460 res = regmap_write(priv->map, DS1343_STATUS_REG, stat);
461 if (res)
462 return res;
463
464 buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
465 0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
466 buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
467 0x80 : bin2bcd(priv->alarm_min) & 0x7F;
468 buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
469 0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
470 buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
471 0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
472
473 res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
474 if (res)
475 return res;
476
477 if (priv->irqen) {
478 control |= DS1343_A0IE;
479 res = regmap_write(priv->map, DS1343_CONTROL_REG, control);
480 }
481
482 return res;
483}
484
485static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
486{
487 struct ds1343_priv *priv = dev_get_drvdata(dev);
488 int res = 0;
489 unsigned int stat;
490
491 if (priv->irq <= 0)
492 return -EINVAL;
493
494 mutex_lock(&priv->mutex);
495
496 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
497 if (res)
498 goto out;
499
500 alarm->enabled = !!(priv->irqen & RTC_AF);
501 alarm->pending = !!(stat & DS1343_IRQF0);
502
503 alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
504 alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
505 alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
506 alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
507
508 alarm->time.tm_mon = -1;
509 alarm->time.tm_year = -1;
510 alarm->time.tm_wday = -1;
511 alarm->time.tm_yday = -1;
512 alarm->time.tm_isdst = -1;
513
514out:
515 mutex_unlock(&priv->mutex);
516 return res;
517}
518
519static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
520{
521 struct ds1343_priv *priv = dev_get_drvdata(dev);
522 int res = 0;
523
524 if (priv->irq <= 0)
525 return -EINVAL;
526
527 mutex_lock(&priv->mutex);
528
529 priv->alarm_sec = alarm->time.tm_sec;
530 priv->alarm_min = alarm->time.tm_min;
531 priv->alarm_hour = alarm->time.tm_hour;
532 priv->alarm_mday = alarm->time.tm_mday;
533
534 if (alarm->enabled)
535 priv->irqen |= RTC_AF;
536
537 res = ds1343_update_alarm(dev);
538
539 mutex_unlock(&priv->mutex);
540
541 return res;
542}
543
544static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
545{
546 struct ds1343_priv *priv = dev_get_drvdata(dev);
547 int res = 0;
548
549 if (priv->irq <= 0)
550 return -EINVAL;
551
552 mutex_lock(&priv->mutex);
553
554 if (enabled)
555 priv->irqen |= RTC_AF;
556 else
557 priv->irqen &= ~RTC_AF;
558
559 res = ds1343_update_alarm(dev);
560
561 mutex_unlock(&priv->mutex);
562
563 return res;
564}
565
566static irqreturn_t ds1343_thread(int irq, void *dev_id)
567{
568 struct ds1343_priv *priv = dev_id;
569 unsigned int stat, control;
570 int res = 0;
571
572 mutex_lock(&priv->mutex);
573
574 res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
575 if (res)
576 goto out;
577
578 if (stat & DS1343_IRQF0) {
579 stat &= ~DS1343_IRQF0;
580 regmap_write(priv->map, DS1343_STATUS_REG, stat);
581
582 res = regmap_read(priv->map, DS1343_CONTROL_REG, &control);
583 if (res)
584 goto out;
585
586 control &= ~DS1343_A0IE;
587 regmap_write(priv->map, DS1343_CONTROL_REG, control);
588
589 rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
590 }
591
592out:
593 mutex_unlock(&priv->mutex);
594 return IRQ_HANDLED;
595}
596
597static const struct rtc_class_ops ds1343_rtc_ops = {
598 .ioctl = ds1343_ioctl,
599 .read_time = ds1343_read_time,
600 .set_time = ds1343_set_time,
601 .read_alarm = ds1343_read_alarm,
602 .set_alarm = ds1343_set_alarm,
603 .alarm_irq_enable = ds1343_alarm_irq_enable,
604};
605
606static int ds1343_probe(struct spi_device *spi)
607{
608 struct ds1343_priv *priv;
609 struct regmap_config config;
610 unsigned int data;
611 int res;
612
613 memset(&config, 0, sizeof(config));
614 config.reg_bits = 8;
615 config.val_bits = 8;
616 config.write_flag_mask = 0x80;
617
618 priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
619 if (!priv)
620 return -ENOMEM;
621
622 priv->spi = spi;
623 mutex_init(&priv->mutex);
624
625 /* RTC DS1347 works in spi mode 3 and
626 * its chip select is active high
627 */
628 spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
629 spi->bits_per_word = 8;
630 res = spi_setup(spi);
631 if (res)
632 return res;
633
634 spi_set_drvdata(spi, priv);
635
636 priv->map = devm_regmap_init_spi(spi, &config);
637
638 if (IS_ERR(priv->map)) {
639 dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
640 return PTR_ERR(priv->map);
641 }
642
643 res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
644 if (res)
645 return res;
646
647 regmap_read(priv->map, DS1343_CONTROL_REG, &data);
648 data |= DS1343_INTCN;
649 data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
650 regmap_write(priv->map, DS1343_CONTROL_REG, data);
651
652 regmap_read(priv->map, DS1343_STATUS_REG, &data);
653 data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
654 regmap_write(priv->map, DS1343_STATUS_REG, data);
655
656 priv->rtc = devm_rtc_device_register(&spi->dev, "ds1343",
657 &ds1343_rtc_ops, THIS_MODULE);
658 if (IS_ERR(priv->rtc)) {
659 dev_err(&spi->dev, "unable to register rtc ds1343\n");
660 return PTR_ERR(priv->rtc);
661 }
662
663 priv->irq = spi->irq;
664
665 if (priv->irq >= 0) {
666 res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
667 ds1343_thread, IRQF_ONESHOT,
668 "ds1343", priv);
669 if (res) {
670 priv->irq = -1;
671 dev_err(&spi->dev,
672 "unable to request irq for rtc ds1343\n");
673 } else {
674 device_init_wakeup(&spi->dev, true);
675 dev_pm_set_wake_irq(&spi->dev, spi->irq);
676 }
677 }
678
679 res = ds1343_sysfs_register(&spi->dev);
680 if (res)
681 dev_err(&spi->dev,
682 "unable to create sysfs entries for rtc ds1343\n");
683
684 return 0;
685}
686
687static int ds1343_remove(struct spi_device *spi)
688{
689 struct ds1343_priv *priv = spi_get_drvdata(spi);
690
691 if (spi->irq) {
692 mutex_lock(&priv->mutex);
693 priv->irqen &= ~RTC_AF;
694 mutex_unlock(&priv->mutex);
695
696 dev_pm_clear_wake_irq(&spi->dev);
697 device_init_wakeup(&spi->dev, false);
698 devm_free_irq(&spi->dev, spi->irq, priv);
699 }
700
701 spi_set_drvdata(spi, NULL);
702
703 ds1343_sysfs_unregister(&spi->dev);
704
705 return 0;
706}
707
708#ifdef CONFIG_PM_SLEEP
709
710static int ds1343_suspend(struct device *dev)
711{
712 struct spi_device *spi = to_spi_device(dev);
713
714 if (spi->irq >= 0 && device_may_wakeup(dev))
715 enable_irq_wake(spi->irq);
716
717 return 0;
718}
719
720static int ds1343_resume(struct device *dev)
721{
722 struct spi_device *spi = to_spi_device(dev);
723
724 if (spi->irq >= 0 && device_may_wakeup(dev))
725 disable_irq_wake(spi->irq);
726
727 return 0;
728}
729
730#endif
731
732static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
733
734static struct spi_driver ds1343_driver = {
735 .driver = {
736 .name = "ds1343",
737 .pm = &ds1343_pm,
738 },
739 .probe = ds1343_probe,
740 .remove = ds1343_remove,
741 .id_table = ds1343_id,
742};
743
744module_spi_driver(ds1343_driver);
745
746MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
747MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
748 "Ankur Srivastava <sankurece@gmail.com>");
749MODULE_LICENSE("GPL v2");
750MODULE_VERSION(DS1343_DRV_VERSION);
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
74static const struct spi_device_id ds1343_id[] = {
75 { "ds1343", DALLAS_MAXIM_DS1343 },
76 { "ds1344", DALLAS_MAXIM_DS1344 },
77 { }
78};
79MODULE_DEVICE_TABLE(spi, ds1343_id);
80
81struct 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
94static 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
114static 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
130static 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
153static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
154 ds1343_store_glitchfilter);
155
156static 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
164static 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
172static 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
214static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
215
216static 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
233static 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
239static 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
260static 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
305static 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
352static 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
375out:
376 mutex_unlock(&priv->mutex);
377 return res;
378}
379
380static 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
405static 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
427static 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
453out:
454 mutex_unlock(&priv->mutex);
455 return IRQ_HANDLED;
456}
457
458static 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
467static 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
559static 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
582static 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
592static 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
604static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
605
606static 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
616module_spi_driver(ds1343_driver);
617
618MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
619MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
620 "Ankur Srivastava <sankurece@gmail.com>");
621MODULE_LICENSE("GPL v2");