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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C and SPI driver for the NXP PCF2127/29 RTC
4 * Copyright 2013 Til-Technologies
5 *
6 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
7 *
8 * Watchdog and tamper functions
9 * Author: Bruno Thomsen <bruno.thomsen@gmail.com>
10 *
11 * based on the other drivers in this same directory.
12 *
13 * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf
14 */
15
16#include <linux/i2c.h>
17#include <linux/spi/spi.h>
18#include <linux/bcd.h>
19#include <linux/rtc.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/of_irq.h>
24#include <linux/regmap.h>
25#include <linux/watchdog.h>
26
27/* Control register 1 */
28#define PCF2127_REG_CTRL1 0x00
29#define PCF2127_BIT_CTRL1_TSF1 BIT(4)
30/* Control register 2 */
31#define PCF2127_REG_CTRL2 0x01
32#define PCF2127_BIT_CTRL2_AIE BIT(1)
33#define PCF2127_BIT_CTRL2_TSIE BIT(2)
34#define PCF2127_BIT_CTRL2_AF BIT(4)
35#define PCF2127_BIT_CTRL2_TSF2 BIT(5)
36#define PCF2127_BIT_CTRL2_WDTF BIT(6)
37/* Control register 3 */
38#define PCF2127_REG_CTRL3 0x02
39#define PCF2127_BIT_CTRL3_BLIE BIT(0)
40#define PCF2127_BIT_CTRL3_BIE BIT(1)
41#define PCF2127_BIT_CTRL3_BLF BIT(2)
42#define PCF2127_BIT_CTRL3_BF BIT(3)
43#define PCF2127_BIT_CTRL3_BTSE BIT(4)
44/* Time and date registers */
45#define PCF2127_REG_SC 0x03
46#define PCF2127_BIT_SC_OSF BIT(7)
47#define PCF2127_REG_MN 0x04
48#define PCF2127_REG_HR 0x05
49#define PCF2127_REG_DM 0x06
50#define PCF2127_REG_DW 0x07
51#define PCF2127_REG_MO 0x08
52#define PCF2127_REG_YR 0x09
53/* Alarm registers */
54#define PCF2127_REG_ALARM_SC 0x0A
55#define PCF2127_REG_ALARM_MN 0x0B
56#define PCF2127_REG_ALARM_HR 0x0C
57#define PCF2127_REG_ALARM_DM 0x0D
58#define PCF2127_REG_ALARM_DW 0x0E
59#define PCF2127_BIT_ALARM_AE BIT(7)
60/* Watchdog registers */
61#define PCF2127_REG_WD_CTL 0x10
62#define PCF2127_BIT_WD_CTL_TF0 BIT(0)
63#define PCF2127_BIT_WD_CTL_TF1 BIT(1)
64#define PCF2127_BIT_WD_CTL_CD0 BIT(6)
65#define PCF2127_BIT_WD_CTL_CD1 BIT(7)
66#define PCF2127_REG_WD_VAL 0x11
67/* Tamper timestamp registers */
68#define PCF2127_REG_TS_CTRL 0x12
69#define PCF2127_BIT_TS_CTRL_TSOFF BIT(6)
70#define PCF2127_BIT_TS_CTRL_TSM BIT(7)
71#define PCF2127_REG_TS_SC 0x13
72#define PCF2127_REG_TS_MN 0x14
73#define PCF2127_REG_TS_HR 0x15
74#define PCF2127_REG_TS_DM 0x16
75#define PCF2127_REG_TS_MO 0x17
76#define PCF2127_REG_TS_YR 0x18
77/*
78 * RAM registers
79 * PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
80 * battery backed and can survive a power outage.
81 * PCF2129 doesn't have this feature.
82 */
83#define PCF2127_REG_RAM_ADDR_MSB 0x1A
84#define PCF2127_REG_RAM_WRT_CMD 0x1C
85#define PCF2127_REG_RAM_RD_CMD 0x1D
86
87/* Watchdog timer value constants */
88#define PCF2127_WD_VAL_STOP 0
89#define PCF2127_WD_VAL_MIN 2
90#define PCF2127_WD_VAL_MAX 255
91#define PCF2127_WD_VAL_DEFAULT 60
92
93struct pcf2127 {
94 struct rtc_device *rtc;
95 struct watchdog_device wdd;
96 struct regmap *regmap;
97};
98
99/*
100 * In the routines that deal directly with the pcf2127 hardware, we use
101 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
102 */
103static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
104{
105 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
106 unsigned char buf[10];
107 int ret;
108
109 /*
110 * Avoid reading CTRL2 register as it causes WD_VAL register
111 * value to reset to 0 which means watchdog is stopped.
112 */
113 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
114 (buf + PCF2127_REG_CTRL3),
115 ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
116 if (ret) {
117 dev_err(dev, "%s: read error\n", __func__);
118 return ret;
119 }
120
121 if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
122 dev_info(dev,
123 "low voltage detected, check/replace RTC battery.\n");
124
125 /* Clock integrity is not guaranteed when OSF flag is set. */
126 if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
127 /*
128 * no need clear the flag here,
129 * it will be cleared once the new date is saved
130 */
131 dev_warn(dev,
132 "oscillator stop detected, date/time is not reliable\n");
133 return -EINVAL;
134 }
135
136 dev_dbg(dev,
137 "%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
138 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
139 __func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
140 buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
141 buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
142 buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
143
144 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
145 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
146 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
147 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
148 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
149 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
150 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
151 tm->tm_year += 100;
152
153 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
154 "mday=%d, mon=%d, year=%d, wday=%d\n",
155 __func__,
156 tm->tm_sec, tm->tm_min, tm->tm_hour,
157 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
158
159 return 0;
160}
161
162static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
163{
164 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
165 unsigned char buf[7];
166 int i = 0, err;
167
168 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
169 "mday=%d, mon=%d, year=%d, wday=%d\n",
170 __func__,
171 tm->tm_sec, tm->tm_min, tm->tm_hour,
172 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
173
174 /* hours, minutes and seconds */
175 buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
176 buf[i++] = bin2bcd(tm->tm_min);
177 buf[i++] = bin2bcd(tm->tm_hour);
178 buf[i++] = bin2bcd(tm->tm_mday);
179 buf[i++] = tm->tm_wday & 0x07;
180
181 /* month, 1 - 12 */
182 buf[i++] = bin2bcd(tm->tm_mon + 1);
183
184 /* year */
185 buf[i++] = bin2bcd(tm->tm_year - 100);
186
187 /* write register's data */
188 err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
189 if (err) {
190 dev_err(dev,
191 "%s: err=%d", __func__, err);
192 return err;
193 }
194
195 return 0;
196}
197
198static int pcf2127_rtc_ioctl(struct device *dev,
199 unsigned int cmd, unsigned long arg)
200{
201 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
202 int val, touser = 0;
203 int ret;
204
205 switch (cmd) {
206 case RTC_VL_READ:
207 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &val);
208 if (ret)
209 return ret;
210
211 if (val & PCF2127_BIT_CTRL3_BLF)
212 touser |= RTC_VL_BACKUP_LOW;
213
214 if (val & PCF2127_BIT_CTRL3_BF)
215 touser |= RTC_VL_BACKUP_SWITCH;
216
217 return put_user(touser, (unsigned int __user *)arg);
218
219 case RTC_VL_CLR:
220 return regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
221 PCF2127_BIT_CTRL3_BF, 0);
222
223 default:
224 return -ENOIOCTLCMD;
225 }
226}
227
228static const struct rtc_class_ops pcf2127_rtc_ops = {
229 .ioctl = pcf2127_rtc_ioctl,
230 .read_time = pcf2127_rtc_read_time,
231 .set_time = pcf2127_rtc_set_time,
232};
233
234static int pcf2127_nvmem_read(void *priv, unsigned int offset,
235 void *val, size_t bytes)
236{
237 struct pcf2127 *pcf2127 = priv;
238 int ret;
239 unsigned char offsetbuf[] = { offset >> 8, offset };
240
241 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
242 offsetbuf, 2);
243 if (ret)
244 return ret;
245
246 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_RD_CMD,
247 val, bytes);
248
249 return ret ?: bytes;
250}
251
252static int pcf2127_nvmem_write(void *priv, unsigned int offset,
253 void *val, size_t bytes)
254{
255 struct pcf2127 *pcf2127 = priv;
256 int ret;
257 unsigned char offsetbuf[] = { offset >> 8, offset };
258
259 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
260 offsetbuf, 2);
261 if (ret)
262 return ret;
263
264 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_WRT_CMD,
265 val, bytes);
266
267 return ret ?: bytes;
268}
269
270/* watchdog driver */
271
272static int pcf2127_wdt_ping(struct watchdog_device *wdd)
273{
274 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
275
276 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL, wdd->timeout);
277}
278
279/*
280 * Restart watchdog timer if feature is active.
281 *
282 * Note: Reading CTRL2 register causes watchdog to stop which is unfortunate,
283 * since register also contain control/status flags for other features.
284 * Always call this function after reading CTRL2 register.
285 */
286static int pcf2127_wdt_active_ping(struct watchdog_device *wdd)
287{
288 int ret = 0;
289
290 if (watchdog_active(wdd)) {
291 ret = pcf2127_wdt_ping(wdd);
292 if (ret)
293 dev_err(wdd->parent,
294 "%s: watchdog restart failed, ret=%d\n",
295 __func__, ret);
296 }
297
298 return ret;
299}
300
301static int pcf2127_wdt_start(struct watchdog_device *wdd)
302{
303 return pcf2127_wdt_ping(wdd);
304}
305
306static int pcf2127_wdt_stop(struct watchdog_device *wdd)
307{
308 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
309
310 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL,
311 PCF2127_WD_VAL_STOP);
312}
313
314static int pcf2127_wdt_set_timeout(struct watchdog_device *wdd,
315 unsigned int new_timeout)
316{
317 dev_dbg(wdd->parent, "new watchdog timeout: %is (old: %is)\n",
318 new_timeout, wdd->timeout);
319
320 wdd->timeout = new_timeout;
321
322 return pcf2127_wdt_active_ping(wdd);
323}
324
325static const struct watchdog_info pcf2127_wdt_info = {
326 .identity = "NXP PCF2127/PCF2129 Watchdog",
327 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
328};
329
330static const struct watchdog_ops pcf2127_watchdog_ops = {
331 .owner = THIS_MODULE,
332 .start = pcf2127_wdt_start,
333 .stop = pcf2127_wdt_stop,
334 .ping = pcf2127_wdt_ping,
335 .set_timeout = pcf2127_wdt_set_timeout,
336};
337
338/* Alarm */
339static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
340{
341 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
342 unsigned int buf[5], ctrl2;
343 int ret;
344
345 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
346 if (ret)
347 return ret;
348
349 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
350 if (ret)
351 return ret;
352
353 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
354 sizeof(buf));
355 if (ret)
356 return ret;
357
358 alrm->enabled = ctrl2 & PCF2127_BIT_CTRL2_AIE;
359 alrm->pending = ctrl2 & PCF2127_BIT_CTRL2_AF;
360
361 alrm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
362 alrm->time.tm_min = bcd2bin(buf[1] & 0x7F);
363 alrm->time.tm_hour = bcd2bin(buf[2] & 0x3F);
364 alrm->time.tm_mday = bcd2bin(buf[3] & 0x3F);
365
366 return 0;
367}
368
369static int pcf2127_rtc_alarm_irq_enable(struct device *dev, u32 enable)
370{
371 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
372 int ret;
373
374 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
375 PCF2127_BIT_CTRL2_AIE,
376 enable ? PCF2127_BIT_CTRL2_AIE : 0);
377 if (ret)
378 return ret;
379
380 return pcf2127_wdt_active_ping(&pcf2127->wdd);
381}
382
383static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
384{
385 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
386 uint8_t buf[5];
387 int ret;
388
389 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
390 PCF2127_BIT_CTRL2_AF, 0);
391 if (ret)
392 return ret;
393
394 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
395 if (ret)
396 return ret;
397
398 buf[0] = bin2bcd(alrm->time.tm_sec);
399 buf[1] = bin2bcd(alrm->time.tm_min);
400 buf[2] = bin2bcd(alrm->time.tm_hour);
401 buf[3] = bin2bcd(alrm->time.tm_mday);
402 buf[4] = PCF2127_BIT_ALARM_AE; /* Do not match on week day */
403
404 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
405 sizeof(buf));
406 if (ret)
407 return ret;
408
409 return pcf2127_rtc_alarm_irq_enable(dev, alrm->enabled);
410}
411
412static irqreturn_t pcf2127_rtc_irq(int irq, void *dev)
413{
414 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
415 unsigned int ctrl2 = 0;
416 int ret = 0;
417
418 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
419 if (ret)
420 return IRQ_NONE;
421
422 if (!(ctrl2 & PCF2127_BIT_CTRL2_AF))
423 return IRQ_NONE;
424
425 regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2,
426 ctrl2 & ~(PCF2127_BIT_CTRL2_AF | PCF2127_BIT_CTRL2_WDTF));
427
428 rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF);
429
430 pcf2127_wdt_active_ping(&pcf2127->wdd);
431
432 return IRQ_HANDLED;
433}
434
435static const struct rtc_class_ops pcf2127_rtc_alrm_ops = {
436 .ioctl = pcf2127_rtc_ioctl,
437 .read_time = pcf2127_rtc_read_time,
438 .set_time = pcf2127_rtc_set_time,
439 .read_alarm = pcf2127_rtc_read_alarm,
440 .set_alarm = pcf2127_rtc_set_alarm,
441 .alarm_irq_enable = pcf2127_rtc_alarm_irq_enable,
442};
443
444/* sysfs interface */
445
446static ssize_t timestamp0_store(struct device *dev,
447 struct device_attribute *attr,
448 const char *buf, size_t count)
449{
450 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
451 int ret;
452
453 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
454 PCF2127_BIT_CTRL1_TSF1, 0);
455 if (ret) {
456 dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
457 return ret;
458 }
459
460 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
461 PCF2127_BIT_CTRL2_TSF2, 0);
462 if (ret) {
463 dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
464 return ret;
465 }
466
467 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
468 if (ret)
469 return ret;
470
471 return count;
472};
473
474static ssize_t timestamp0_show(struct device *dev,
475 struct device_attribute *attr, char *buf)
476{
477 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
478 struct rtc_time tm;
479 int ret;
480 unsigned char data[25];
481
482 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
483 sizeof(data));
484 if (ret) {
485 dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
486 return ret;
487 }
488
489 dev_dbg(dev,
490 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, "
491 "ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
492 __func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
493 data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
494 data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
495 data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
496 data[PCF2127_REG_TS_YR]);
497
498 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
499 if (ret)
500 return ret;
501
502 if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) &&
503 !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2))
504 return 0;
505
506 tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
507 tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
508 tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
509 tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
510 /* TS_MO register (month) value range: 1-12 */
511 tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
512 tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
513 if (tm.tm_year < 70)
514 tm.tm_year += 100; /* assume we are in 1970...2069 */
515
516 ret = rtc_valid_tm(&tm);
517 if (ret)
518 return ret;
519
520 return sprintf(buf, "%llu\n",
521 (unsigned long long)rtc_tm_to_time64(&tm));
522};
523
524static DEVICE_ATTR_RW(timestamp0);
525
526static struct attribute *pcf2127_attrs[] = {
527 &dev_attr_timestamp0.attr,
528 NULL
529};
530
531static const struct attribute_group pcf2127_attr_group = {
532 .attrs = pcf2127_attrs,
533};
534
535static int pcf2127_probe(struct device *dev, struct regmap *regmap,
536 int alarm_irq, const char *name, bool has_nvmem)
537{
538 struct pcf2127 *pcf2127;
539 u32 wdd_timeout;
540 int ret = 0;
541
542 dev_dbg(dev, "%s\n", __func__);
543
544 pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
545 if (!pcf2127)
546 return -ENOMEM;
547
548 pcf2127->regmap = regmap;
549
550 dev_set_drvdata(dev, pcf2127);
551
552 pcf2127->rtc = devm_rtc_allocate_device(dev);
553 if (IS_ERR(pcf2127->rtc))
554 return PTR_ERR(pcf2127->rtc);
555
556 pcf2127->rtc->ops = &pcf2127_rtc_ops;
557 pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
558 pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;
559 pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */
560 pcf2127->rtc->uie_unsupported = 1;
561
562 if (alarm_irq >= 0) {
563 ret = devm_request_threaded_irq(dev, alarm_irq, NULL,
564 pcf2127_rtc_irq,
565 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
566 dev_name(dev), dev);
567 if (ret) {
568 dev_err(dev, "failed to request alarm irq\n");
569 return ret;
570 }
571 }
572
573 if (alarm_irq >= 0 || device_property_read_bool(dev, "wakeup-source")) {
574 device_init_wakeup(dev, true);
575 pcf2127->rtc->ops = &pcf2127_rtc_alrm_ops;
576 }
577
578 pcf2127->wdd.parent = dev;
579 pcf2127->wdd.info = &pcf2127_wdt_info;
580 pcf2127->wdd.ops = &pcf2127_watchdog_ops;
581 pcf2127->wdd.min_timeout = PCF2127_WD_VAL_MIN;
582 pcf2127->wdd.max_timeout = PCF2127_WD_VAL_MAX;
583 pcf2127->wdd.timeout = PCF2127_WD_VAL_DEFAULT;
584 pcf2127->wdd.min_hw_heartbeat_ms = 500;
585 pcf2127->wdd.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
586
587 watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
588
589 if (has_nvmem) {
590 struct nvmem_config nvmem_cfg = {
591 .priv = pcf2127,
592 .reg_read = pcf2127_nvmem_read,
593 .reg_write = pcf2127_nvmem_write,
594 .size = 512,
595 };
596
597 ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
598 }
599
600 /*
601 * Watchdog timer enabled and reset pin /RST activated when timed out.
602 * Select 1Hz clock source for watchdog timer.
603 * Note: Countdown timer disabled and not available.
604 */
605 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
606 PCF2127_BIT_WD_CTL_CD1 |
607 PCF2127_BIT_WD_CTL_CD0 |
608 PCF2127_BIT_WD_CTL_TF1 |
609 PCF2127_BIT_WD_CTL_TF0,
610 PCF2127_BIT_WD_CTL_CD1 |
611 PCF2127_BIT_WD_CTL_CD0 |
612 PCF2127_BIT_WD_CTL_TF1);
613 if (ret) {
614 dev_err(dev, "%s: watchdog config (wd_ctl) failed\n", __func__);
615 return ret;
616 }
617
618 /* Test if watchdog timer is started by bootloader */
619 ret = regmap_read(pcf2127->regmap, PCF2127_REG_WD_VAL, &wdd_timeout);
620 if (ret)
621 return ret;
622
623 if (wdd_timeout)
624 set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
625
626#ifdef CONFIG_WATCHDOG
627 ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
628 if (ret)
629 return ret;
630#endif /* CONFIG_WATCHDOG */
631
632 /*
633 * Disable battery low/switch-over timestamp and interrupts.
634 * Clear battery interrupt flags which can block new trigger events.
635 * Note: This is the default chip behaviour but added to ensure
636 * correct tamper timestamp and interrupt function.
637 */
638 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
639 PCF2127_BIT_CTRL3_BTSE |
640 PCF2127_BIT_CTRL3_BIE |
641 PCF2127_BIT_CTRL3_BLIE, 0);
642 if (ret) {
643 dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
644 __func__);
645 return ret;
646 }
647
648 /*
649 * Enable timestamp function and store timestamp of first trigger
650 * event until TSF1 and TFS2 interrupt flags are cleared.
651 */
652 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
653 PCF2127_BIT_TS_CTRL_TSOFF |
654 PCF2127_BIT_TS_CTRL_TSM,
655 PCF2127_BIT_TS_CTRL_TSM);
656 if (ret) {
657 dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",
658 __func__);
659 return ret;
660 }
661
662 /*
663 * Enable interrupt generation when TSF1 or TSF2 timestamp flags
664 * are set. Interrupt signal is an open-drain output and can be
665 * left floating if unused.
666 */
667 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
668 PCF2127_BIT_CTRL2_TSIE,
669 PCF2127_BIT_CTRL2_TSIE);
670 if (ret) {
671 dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",
672 __func__);
673 return ret;
674 }
675
676 ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
677 if (ret) {
678 dev_err(dev, "%s: tamper sysfs registering failed\n",
679 __func__);
680 return ret;
681 }
682
683 return rtc_register_device(pcf2127->rtc);
684}
685
686#ifdef CONFIG_OF
687static const struct of_device_id pcf2127_of_match[] = {
688 { .compatible = "nxp,pcf2127" },
689 { .compatible = "nxp,pcf2129" },
690 { .compatible = "nxp,pca2129" },
691 {}
692};
693MODULE_DEVICE_TABLE(of, pcf2127_of_match);
694#endif
695
696#if IS_ENABLED(CONFIG_I2C)
697
698static int pcf2127_i2c_write(void *context, const void *data, size_t count)
699{
700 struct device *dev = context;
701 struct i2c_client *client = to_i2c_client(dev);
702 int ret;
703
704 ret = i2c_master_send(client, data, count);
705 if (ret != count)
706 return ret < 0 ? ret : -EIO;
707
708 return 0;
709}
710
711static int pcf2127_i2c_gather_write(void *context,
712 const void *reg, size_t reg_size,
713 const void *val, size_t val_size)
714{
715 struct device *dev = context;
716 struct i2c_client *client = to_i2c_client(dev);
717 int ret;
718 void *buf;
719
720 if (WARN_ON(reg_size != 1))
721 return -EINVAL;
722
723 buf = kmalloc(val_size + 1, GFP_KERNEL);
724 if (!buf)
725 return -ENOMEM;
726
727 memcpy(buf, reg, 1);
728 memcpy(buf + 1, val, val_size);
729
730 ret = i2c_master_send(client, buf, val_size + 1);
731
732 kfree(buf);
733
734 if (ret != val_size + 1)
735 return ret < 0 ? ret : -EIO;
736
737 return 0;
738}
739
740static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
741 void *val, size_t val_size)
742{
743 struct device *dev = context;
744 struct i2c_client *client = to_i2c_client(dev);
745 int ret;
746
747 if (WARN_ON(reg_size != 1))
748 return -EINVAL;
749
750 ret = i2c_master_send(client, reg, 1);
751 if (ret != 1)
752 return ret < 0 ? ret : -EIO;
753
754 ret = i2c_master_recv(client, val, val_size);
755 if (ret != val_size)
756 return ret < 0 ? ret : -EIO;
757
758 return 0;
759}
760
761/*
762 * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
763 * is that the STOP condition is required between set register address and
764 * read register data when reading from registers.
765 */
766static const struct regmap_bus pcf2127_i2c_regmap = {
767 .write = pcf2127_i2c_write,
768 .gather_write = pcf2127_i2c_gather_write,
769 .read = pcf2127_i2c_read,
770};
771
772static struct i2c_driver pcf2127_i2c_driver;
773
774static int pcf2127_i2c_probe(struct i2c_client *client,
775 const struct i2c_device_id *id)
776{
777 struct regmap *regmap;
778 static const struct regmap_config config = {
779 .reg_bits = 8,
780 .val_bits = 8,
781 .max_register = 0x1d,
782 };
783
784 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
785 return -ENODEV;
786
787 regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
788 &client->dev, &config);
789 if (IS_ERR(regmap)) {
790 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
791 __func__, PTR_ERR(regmap));
792 return PTR_ERR(regmap);
793 }
794
795 return pcf2127_probe(&client->dev, regmap, client->irq,
796 pcf2127_i2c_driver.driver.name, id->driver_data);
797}
798
799static const struct i2c_device_id pcf2127_i2c_id[] = {
800 { "pcf2127", 1 },
801 { "pcf2129", 0 },
802 { "pca2129", 0 },
803 { }
804};
805MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
806
807static struct i2c_driver pcf2127_i2c_driver = {
808 .driver = {
809 .name = "rtc-pcf2127-i2c",
810 .of_match_table = of_match_ptr(pcf2127_of_match),
811 },
812 .probe = pcf2127_i2c_probe,
813 .id_table = pcf2127_i2c_id,
814};
815
816static int pcf2127_i2c_register_driver(void)
817{
818 return i2c_add_driver(&pcf2127_i2c_driver);
819}
820
821static void pcf2127_i2c_unregister_driver(void)
822{
823 i2c_del_driver(&pcf2127_i2c_driver);
824}
825
826#else
827
828static int pcf2127_i2c_register_driver(void)
829{
830 return 0;
831}
832
833static void pcf2127_i2c_unregister_driver(void)
834{
835}
836
837#endif
838
839#if IS_ENABLED(CONFIG_SPI_MASTER)
840
841static struct spi_driver pcf2127_spi_driver;
842
843static int pcf2127_spi_probe(struct spi_device *spi)
844{
845 static const struct regmap_config config = {
846 .reg_bits = 8,
847 .val_bits = 8,
848 .read_flag_mask = 0xa0,
849 .write_flag_mask = 0x20,
850 .max_register = 0x1d,
851 };
852 struct regmap *regmap;
853
854 regmap = devm_regmap_init_spi(spi, &config);
855 if (IS_ERR(regmap)) {
856 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
857 __func__, PTR_ERR(regmap));
858 return PTR_ERR(regmap);
859 }
860
861 return pcf2127_probe(&spi->dev, regmap, spi->irq,
862 pcf2127_spi_driver.driver.name,
863 spi_get_device_id(spi)->driver_data);
864}
865
866static const struct spi_device_id pcf2127_spi_id[] = {
867 { "pcf2127", 1 },
868 { "pcf2129", 0 },
869 { "pca2129", 0 },
870 { }
871};
872MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
873
874static struct spi_driver pcf2127_spi_driver = {
875 .driver = {
876 .name = "rtc-pcf2127-spi",
877 .of_match_table = of_match_ptr(pcf2127_of_match),
878 },
879 .probe = pcf2127_spi_probe,
880 .id_table = pcf2127_spi_id,
881};
882
883static int pcf2127_spi_register_driver(void)
884{
885 return spi_register_driver(&pcf2127_spi_driver);
886}
887
888static void pcf2127_spi_unregister_driver(void)
889{
890 spi_unregister_driver(&pcf2127_spi_driver);
891}
892
893#else
894
895static int pcf2127_spi_register_driver(void)
896{
897 return 0;
898}
899
900static void pcf2127_spi_unregister_driver(void)
901{
902}
903
904#endif
905
906static int __init pcf2127_init(void)
907{
908 int ret;
909
910 ret = pcf2127_i2c_register_driver();
911 if (ret) {
912 pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
913 return ret;
914 }
915
916 ret = pcf2127_spi_register_driver();
917 if (ret) {
918 pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
919 pcf2127_i2c_unregister_driver();
920 }
921
922 return ret;
923}
924module_init(pcf2127_init)
925
926static void __exit pcf2127_exit(void)
927{
928 pcf2127_spi_unregister_driver();
929 pcf2127_i2c_unregister_driver();
930}
931module_exit(pcf2127_exit)
932
933MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
934MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
935MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C and SPI driver for the NXP PCF2127/29 RTC
4 * Copyright 2013 Til-Technologies
5 *
6 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
7 *
8 * Watchdog and tamper functions
9 * Author: Bruno Thomsen <bruno.thomsen@gmail.com>
10 *
11 * based on the other drivers in this same directory.
12 *
13 * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf
14 */
15
16#include <linux/i2c.h>
17#include <linux/spi/spi.h>
18#include <linux/bcd.h>
19#include <linux/rtc.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/regmap.h>
24#include <linux/watchdog.h>
25
26/* Control register 1 */
27#define PCF2127_REG_CTRL1 0x00
28#define PCF2127_BIT_CTRL1_TSF1 BIT(4)
29/* Control register 2 */
30#define PCF2127_REG_CTRL2 0x01
31#define PCF2127_BIT_CTRL2_TSIE BIT(2)
32#define PCF2127_BIT_CTRL2_TSF2 BIT(5)
33/* Control register 3 */
34#define PCF2127_REG_CTRL3 0x02
35#define PCF2127_BIT_CTRL3_BLIE BIT(0)
36#define PCF2127_BIT_CTRL3_BIE BIT(1)
37#define PCF2127_BIT_CTRL3_BLF BIT(2)
38#define PCF2127_BIT_CTRL3_BF BIT(3)
39#define PCF2127_BIT_CTRL3_BTSE BIT(4)
40/* Time and date registers */
41#define PCF2127_REG_SC 0x03
42#define PCF2127_BIT_SC_OSF BIT(7)
43#define PCF2127_REG_MN 0x04
44#define PCF2127_REG_HR 0x05
45#define PCF2127_REG_DM 0x06
46#define PCF2127_REG_DW 0x07
47#define PCF2127_REG_MO 0x08
48#define PCF2127_REG_YR 0x09
49/* Watchdog registers */
50#define PCF2127_REG_WD_CTL 0x10
51#define PCF2127_BIT_WD_CTL_TF0 BIT(0)
52#define PCF2127_BIT_WD_CTL_TF1 BIT(1)
53#define PCF2127_BIT_WD_CTL_CD0 BIT(6)
54#define PCF2127_BIT_WD_CTL_CD1 BIT(7)
55#define PCF2127_REG_WD_VAL 0x11
56/* Tamper timestamp registers */
57#define PCF2127_REG_TS_CTRL 0x12
58#define PCF2127_BIT_TS_CTRL_TSOFF BIT(6)
59#define PCF2127_BIT_TS_CTRL_TSM BIT(7)
60#define PCF2127_REG_TS_SC 0x13
61#define PCF2127_REG_TS_MN 0x14
62#define PCF2127_REG_TS_HR 0x15
63#define PCF2127_REG_TS_DM 0x16
64#define PCF2127_REG_TS_MO 0x17
65#define PCF2127_REG_TS_YR 0x18
66/*
67 * RAM registers
68 * PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
69 * battery backed and can survive a power outage.
70 * PCF2129 doesn't have this feature.
71 */
72#define PCF2127_REG_RAM_ADDR_MSB 0x1A
73#define PCF2127_REG_RAM_WRT_CMD 0x1C
74#define PCF2127_REG_RAM_RD_CMD 0x1D
75
76/* Watchdog timer value constants */
77#define PCF2127_WD_VAL_STOP 0
78#define PCF2127_WD_VAL_MIN 2
79#define PCF2127_WD_VAL_MAX 255
80#define PCF2127_WD_VAL_DEFAULT 60
81
82struct pcf2127 {
83 struct rtc_device *rtc;
84 struct watchdog_device wdd;
85 struct regmap *regmap;
86};
87
88/*
89 * In the routines that deal directly with the pcf2127 hardware, we use
90 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
91 */
92static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
93{
94 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
95 unsigned char buf[10];
96 int ret;
97
98 /*
99 * Avoid reading CTRL2 register as it causes WD_VAL register
100 * value to reset to 0 which means watchdog is stopped.
101 */
102 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
103 (buf + PCF2127_REG_CTRL3),
104 ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
105 if (ret) {
106 dev_err(dev, "%s: read error\n", __func__);
107 return ret;
108 }
109
110 if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
111 dev_info(dev,
112 "low voltage detected, check/replace RTC battery.\n");
113
114 /* Clock integrity is not guaranteed when OSF flag is set. */
115 if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
116 /*
117 * no need clear the flag here,
118 * it will be cleared once the new date is saved
119 */
120 dev_warn(dev,
121 "oscillator stop detected, date/time is not reliable\n");
122 return -EINVAL;
123 }
124
125 dev_dbg(dev,
126 "%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
127 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
128 __func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
129 buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
130 buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
131 buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
132
133 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
134 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
135 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
136 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
137 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
138 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
139 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
140 if (tm->tm_year < 70)
141 tm->tm_year += 100; /* assume we are in 1970...2069 */
142
143 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
144 "mday=%d, mon=%d, year=%d, wday=%d\n",
145 __func__,
146 tm->tm_sec, tm->tm_min, tm->tm_hour,
147 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
148
149 return 0;
150}
151
152static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
153{
154 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
155 unsigned char buf[7];
156 int i = 0, err;
157
158 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
159 "mday=%d, mon=%d, year=%d, wday=%d\n",
160 __func__,
161 tm->tm_sec, tm->tm_min, tm->tm_hour,
162 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
163
164 /* hours, minutes and seconds */
165 buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
166 buf[i++] = bin2bcd(tm->tm_min);
167 buf[i++] = bin2bcd(tm->tm_hour);
168 buf[i++] = bin2bcd(tm->tm_mday);
169 buf[i++] = tm->tm_wday & 0x07;
170
171 /* month, 1 - 12 */
172 buf[i++] = bin2bcd(tm->tm_mon + 1);
173
174 /* year */
175 buf[i++] = bin2bcd(tm->tm_year % 100);
176
177 /* write register's data */
178 err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
179 if (err) {
180 dev_err(dev,
181 "%s: err=%d", __func__, err);
182 return err;
183 }
184
185 return 0;
186}
187
188#ifdef CONFIG_RTC_INTF_DEV
189static int pcf2127_rtc_ioctl(struct device *dev,
190 unsigned int cmd, unsigned long arg)
191{
192 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
193 int touser;
194 int ret;
195
196 switch (cmd) {
197 case RTC_VL_READ:
198 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser);
199 if (ret)
200 return ret;
201
202 touser = touser & PCF2127_BIT_CTRL3_BLF ? 1 : 0;
203
204 if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
205 return -EFAULT;
206 return 0;
207 default:
208 return -ENOIOCTLCMD;
209 }
210}
211#else
212#define pcf2127_rtc_ioctl NULL
213#endif
214
215static const struct rtc_class_ops pcf2127_rtc_ops = {
216 .ioctl = pcf2127_rtc_ioctl,
217 .read_time = pcf2127_rtc_read_time,
218 .set_time = pcf2127_rtc_set_time,
219};
220
221static int pcf2127_nvmem_read(void *priv, unsigned int offset,
222 void *val, size_t bytes)
223{
224 struct pcf2127 *pcf2127 = priv;
225 int ret;
226 unsigned char offsetbuf[] = { offset >> 8, offset };
227
228 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
229 offsetbuf, 2);
230 if (ret)
231 return ret;
232
233 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_RD_CMD,
234 val, bytes);
235
236 return ret ?: bytes;
237}
238
239static int pcf2127_nvmem_write(void *priv, unsigned int offset,
240 void *val, size_t bytes)
241{
242 struct pcf2127 *pcf2127 = priv;
243 int ret;
244 unsigned char offsetbuf[] = { offset >> 8, offset };
245
246 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
247 offsetbuf, 2);
248 if (ret)
249 return ret;
250
251 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_WRT_CMD,
252 val, bytes);
253
254 return ret ?: bytes;
255}
256
257/* watchdog driver */
258
259static int pcf2127_wdt_ping(struct watchdog_device *wdd)
260{
261 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
262
263 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL, wdd->timeout);
264}
265
266/*
267 * Restart watchdog timer if feature is active.
268 *
269 * Note: Reading CTRL2 register causes watchdog to stop which is unfortunate,
270 * since register also contain control/status flags for other features.
271 * Always call this function after reading CTRL2 register.
272 */
273static int pcf2127_wdt_active_ping(struct watchdog_device *wdd)
274{
275 int ret = 0;
276
277 if (watchdog_active(wdd)) {
278 ret = pcf2127_wdt_ping(wdd);
279 if (ret)
280 dev_err(wdd->parent,
281 "%s: watchdog restart failed, ret=%d\n",
282 __func__, ret);
283 }
284
285 return ret;
286}
287
288static int pcf2127_wdt_start(struct watchdog_device *wdd)
289{
290 return pcf2127_wdt_ping(wdd);
291}
292
293static int pcf2127_wdt_stop(struct watchdog_device *wdd)
294{
295 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
296
297 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL,
298 PCF2127_WD_VAL_STOP);
299}
300
301static int pcf2127_wdt_set_timeout(struct watchdog_device *wdd,
302 unsigned int new_timeout)
303{
304 dev_dbg(wdd->parent, "new watchdog timeout: %is (old: %is)\n",
305 new_timeout, wdd->timeout);
306
307 wdd->timeout = new_timeout;
308
309 return pcf2127_wdt_active_ping(wdd);
310}
311
312static const struct watchdog_info pcf2127_wdt_info = {
313 .identity = "NXP PCF2127/PCF2129 Watchdog",
314 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
315};
316
317static const struct watchdog_ops pcf2127_watchdog_ops = {
318 .owner = THIS_MODULE,
319 .start = pcf2127_wdt_start,
320 .stop = pcf2127_wdt_stop,
321 .ping = pcf2127_wdt_ping,
322 .set_timeout = pcf2127_wdt_set_timeout,
323};
324
325/* sysfs interface */
326
327static ssize_t timestamp0_store(struct device *dev,
328 struct device_attribute *attr,
329 const char *buf, size_t count)
330{
331 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
332 int ret;
333
334 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
335 PCF2127_BIT_CTRL1_TSF1, 0);
336 if (ret) {
337 dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
338 return ret;
339 }
340
341 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
342 PCF2127_BIT_CTRL2_TSF2, 0);
343 if (ret) {
344 dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
345 return ret;
346 }
347
348 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
349 if (ret)
350 return ret;
351
352 return count;
353};
354
355static ssize_t timestamp0_show(struct device *dev,
356 struct device_attribute *attr, char *buf)
357{
358 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
359 struct rtc_time tm;
360 int ret;
361 unsigned char data[25];
362
363 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
364 sizeof(data));
365 if (ret) {
366 dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
367 return ret;
368 }
369
370 dev_dbg(dev,
371 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, "
372 "ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
373 __func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
374 data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
375 data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
376 data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
377 data[PCF2127_REG_TS_YR]);
378
379 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
380 if (ret)
381 return ret;
382
383 if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) &&
384 !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2))
385 return 0;
386
387 tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
388 tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
389 tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
390 tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
391 /* TS_MO register (month) value range: 1-12 */
392 tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
393 tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
394 if (tm.tm_year < 70)
395 tm.tm_year += 100; /* assume we are in 1970...2069 */
396
397 ret = rtc_valid_tm(&tm);
398 if (ret)
399 return ret;
400
401 return sprintf(buf, "%llu\n",
402 (unsigned long long)rtc_tm_to_time64(&tm));
403};
404
405static DEVICE_ATTR_RW(timestamp0);
406
407static struct attribute *pcf2127_attrs[] = {
408 &dev_attr_timestamp0.attr,
409 NULL
410};
411
412static const struct attribute_group pcf2127_attr_group = {
413 .attrs = pcf2127_attrs,
414};
415
416static int pcf2127_probe(struct device *dev, struct regmap *regmap,
417 const char *name, bool has_nvmem)
418{
419 struct pcf2127 *pcf2127;
420 int ret = 0;
421
422 dev_dbg(dev, "%s\n", __func__);
423
424 pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
425 if (!pcf2127)
426 return -ENOMEM;
427
428 pcf2127->regmap = regmap;
429
430 dev_set_drvdata(dev, pcf2127);
431
432 pcf2127->rtc = devm_rtc_allocate_device(dev);
433 if (IS_ERR(pcf2127->rtc))
434 return PTR_ERR(pcf2127->rtc);
435
436 pcf2127->rtc->ops = &pcf2127_rtc_ops;
437
438 pcf2127->wdd.parent = dev;
439 pcf2127->wdd.info = &pcf2127_wdt_info;
440 pcf2127->wdd.ops = &pcf2127_watchdog_ops;
441 pcf2127->wdd.min_timeout = PCF2127_WD_VAL_MIN;
442 pcf2127->wdd.max_timeout = PCF2127_WD_VAL_MAX;
443 pcf2127->wdd.timeout = PCF2127_WD_VAL_DEFAULT;
444 pcf2127->wdd.min_hw_heartbeat_ms = 500;
445
446 watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
447
448 if (has_nvmem) {
449 struct nvmem_config nvmem_cfg = {
450 .priv = pcf2127,
451 .reg_read = pcf2127_nvmem_read,
452 .reg_write = pcf2127_nvmem_write,
453 .size = 512,
454 };
455
456 ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
457 }
458
459 /*
460 * Watchdog timer enabled and reset pin /RST activated when timed out.
461 * Select 1Hz clock source for watchdog timer.
462 * Timer is not started until WD_VAL is loaded with a valid value.
463 * Note: Countdown timer disabled and not available.
464 */
465 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
466 PCF2127_BIT_WD_CTL_CD1 |
467 PCF2127_BIT_WD_CTL_CD0 |
468 PCF2127_BIT_WD_CTL_TF1 |
469 PCF2127_BIT_WD_CTL_TF0,
470 PCF2127_BIT_WD_CTL_CD1 |
471 PCF2127_BIT_WD_CTL_CD0 |
472 PCF2127_BIT_WD_CTL_TF1);
473 if (ret) {
474 dev_err(dev, "%s: watchdog config (wd_ctl) failed\n", __func__);
475 return ret;
476 }
477
478#ifdef CONFIG_WATCHDOG
479 ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
480 if (ret)
481 return ret;
482#endif /* CONFIG_WATCHDOG */
483
484 /*
485 * Disable battery low/switch-over timestamp and interrupts.
486 * Clear battery interrupt flags which can block new trigger events.
487 * Note: This is the default chip behaviour but added to ensure
488 * correct tamper timestamp and interrupt function.
489 */
490 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
491 PCF2127_BIT_CTRL3_BTSE |
492 PCF2127_BIT_CTRL3_BF |
493 PCF2127_BIT_CTRL3_BIE |
494 PCF2127_BIT_CTRL3_BLIE, 0);
495 if (ret) {
496 dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
497 __func__);
498 return ret;
499 }
500
501 /*
502 * Enable timestamp function and store timestamp of first trigger
503 * event until TSF1 and TFS2 interrupt flags are cleared.
504 */
505 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
506 PCF2127_BIT_TS_CTRL_TSOFF |
507 PCF2127_BIT_TS_CTRL_TSM,
508 PCF2127_BIT_TS_CTRL_TSM);
509 if (ret) {
510 dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",
511 __func__);
512 return ret;
513 }
514
515 /*
516 * Enable interrupt generation when TSF1 or TSF2 timestamp flags
517 * are set. Interrupt signal is an open-drain output and can be
518 * left floating if unused.
519 */
520 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
521 PCF2127_BIT_CTRL2_TSIE,
522 PCF2127_BIT_CTRL2_TSIE);
523 if (ret) {
524 dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",
525 __func__);
526 return ret;
527 }
528
529 ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
530 if (ret) {
531 dev_err(dev, "%s: tamper sysfs registering failed\n",
532 __func__);
533 return ret;
534 }
535
536 return rtc_register_device(pcf2127->rtc);
537}
538
539#ifdef CONFIG_OF
540static const struct of_device_id pcf2127_of_match[] = {
541 { .compatible = "nxp,pcf2127" },
542 { .compatible = "nxp,pcf2129" },
543 {}
544};
545MODULE_DEVICE_TABLE(of, pcf2127_of_match);
546#endif
547
548#if IS_ENABLED(CONFIG_I2C)
549
550static int pcf2127_i2c_write(void *context, const void *data, size_t count)
551{
552 struct device *dev = context;
553 struct i2c_client *client = to_i2c_client(dev);
554 int ret;
555
556 ret = i2c_master_send(client, data, count);
557 if (ret != count)
558 return ret < 0 ? ret : -EIO;
559
560 return 0;
561}
562
563static int pcf2127_i2c_gather_write(void *context,
564 const void *reg, size_t reg_size,
565 const void *val, size_t val_size)
566{
567 struct device *dev = context;
568 struct i2c_client *client = to_i2c_client(dev);
569 int ret;
570 void *buf;
571
572 if (WARN_ON(reg_size != 1))
573 return -EINVAL;
574
575 buf = kmalloc(val_size + 1, GFP_KERNEL);
576 if (!buf)
577 return -ENOMEM;
578
579 memcpy(buf, reg, 1);
580 memcpy(buf + 1, val, val_size);
581
582 ret = i2c_master_send(client, buf, val_size + 1);
583
584 kfree(buf);
585
586 if (ret != val_size + 1)
587 return ret < 0 ? ret : -EIO;
588
589 return 0;
590}
591
592static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
593 void *val, size_t val_size)
594{
595 struct device *dev = context;
596 struct i2c_client *client = to_i2c_client(dev);
597 int ret;
598
599 if (WARN_ON(reg_size != 1))
600 return -EINVAL;
601
602 ret = i2c_master_send(client, reg, 1);
603 if (ret != 1)
604 return ret < 0 ? ret : -EIO;
605
606 ret = i2c_master_recv(client, val, val_size);
607 if (ret != val_size)
608 return ret < 0 ? ret : -EIO;
609
610 return 0;
611}
612
613/*
614 * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
615 * is that the STOP condition is required between set register address and
616 * read register data when reading from registers.
617 */
618static const struct regmap_bus pcf2127_i2c_regmap = {
619 .write = pcf2127_i2c_write,
620 .gather_write = pcf2127_i2c_gather_write,
621 .read = pcf2127_i2c_read,
622};
623
624static struct i2c_driver pcf2127_i2c_driver;
625
626static int pcf2127_i2c_probe(struct i2c_client *client,
627 const struct i2c_device_id *id)
628{
629 struct regmap *regmap;
630 static const struct regmap_config config = {
631 .reg_bits = 8,
632 .val_bits = 8,
633 };
634
635 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
636 return -ENODEV;
637
638 regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
639 &client->dev, &config);
640 if (IS_ERR(regmap)) {
641 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
642 __func__, PTR_ERR(regmap));
643 return PTR_ERR(regmap);
644 }
645
646 return pcf2127_probe(&client->dev, regmap,
647 pcf2127_i2c_driver.driver.name, id->driver_data);
648}
649
650static const struct i2c_device_id pcf2127_i2c_id[] = {
651 { "pcf2127", 1 },
652 { "pcf2129", 0 },
653 { }
654};
655MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
656
657static struct i2c_driver pcf2127_i2c_driver = {
658 .driver = {
659 .name = "rtc-pcf2127-i2c",
660 .of_match_table = of_match_ptr(pcf2127_of_match),
661 },
662 .probe = pcf2127_i2c_probe,
663 .id_table = pcf2127_i2c_id,
664};
665
666static int pcf2127_i2c_register_driver(void)
667{
668 return i2c_add_driver(&pcf2127_i2c_driver);
669}
670
671static void pcf2127_i2c_unregister_driver(void)
672{
673 i2c_del_driver(&pcf2127_i2c_driver);
674}
675
676#else
677
678static int pcf2127_i2c_register_driver(void)
679{
680 return 0;
681}
682
683static void pcf2127_i2c_unregister_driver(void)
684{
685}
686
687#endif
688
689#if IS_ENABLED(CONFIG_SPI_MASTER)
690
691static struct spi_driver pcf2127_spi_driver;
692
693static int pcf2127_spi_probe(struct spi_device *spi)
694{
695 static const struct regmap_config config = {
696 .reg_bits = 8,
697 .val_bits = 8,
698 .read_flag_mask = 0xa0,
699 .write_flag_mask = 0x20,
700 };
701 struct regmap *regmap;
702
703 regmap = devm_regmap_init_spi(spi, &config);
704 if (IS_ERR(regmap)) {
705 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
706 __func__, PTR_ERR(regmap));
707 return PTR_ERR(regmap);
708 }
709
710 return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,
711 spi_get_device_id(spi)->driver_data);
712}
713
714static const struct spi_device_id pcf2127_spi_id[] = {
715 { "pcf2127", 1 },
716 { "pcf2129", 0 },
717 { }
718};
719MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
720
721static struct spi_driver pcf2127_spi_driver = {
722 .driver = {
723 .name = "rtc-pcf2127-spi",
724 .of_match_table = of_match_ptr(pcf2127_of_match),
725 },
726 .probe = pcf2127_spi_probe,
727 .id_table = pcf2127_spi_id,
728};
729
730static int pcf2127_spi_register_driver(void)
731{
732 return spi_register_driver(&pcf2127_spi_driver);
733}
734
735static void pcf2127_spi_unregister_driver(void)
736{
737 spi_unregister_driver(&pcf2127_spi_driver);
738}
739
740#else
741
742static int pcf2127_spi_register_driver(void)
743{
744 return 0;
745}
746
747static void pcf2127_spi_unregister_driver(void)
748{
749}
750
751#endif
752
753static int __init pcf2127_init(void)
754{
755 int ret;
756
757 ret = pcf2127_i2c_register_driver();
758 if (ret) {
759 pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
760 return ret;
761 }
762
763 ret = pcf2127_spi_register_driver();
764 if (ret) {
765 pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
766 pcf2127_i2c_unregister_driver();
767 }
768
769 return ret;
770}
771module_init(pcf2127_init)
772
773static void __exit pcf2127_exit(void)
774{
775 pcf2127_spi_unregister_driver();
776 pcf2127_i2c_unregister_driver();
777}
778module_exit(pcf2127_exit)
779
780MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
781MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
782MODULE_LICENSE("GPL v2");