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[mirror_ubuntu-jammy-kernel.git] / drivers / rtc / rtc-pcf8563.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * An I2C driver for the Philips PCF8563 RTC
4 * Copyright 2005-06 Tower Technologies
5 *
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 * Maintainers: http://www.nslu2-linux.org/
8 *
9 * based on the other drivers in this same directory.
10 *
11 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
12 */
13
14 #include <linux/clk-provider.h>
15 #include <linux/i2c.h>
16 #include <linux/bcd.h>
17 #include <linux/rtc.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/err.h>
22
23 #define PCF8563_REG_ST1 0x00 /* status */
24 #define PCF8563_REG_ST2 0x01
25 #define PCF8563_BIT_AIE BIT(1)
26 #define PCF8563_BIT_AF BIT(3)
27 #define PCF8563_BITS_ST2_N (7 << 5)
28
29 #define PCF8563_REG_SC 0x02 /* datetime */
30 #define PCF8563_REG_MN 0x03
31 #define PCF8563_REG_HR 0x04
32 #define PCF8563_REG_DM 0x05
33 #define PCF8563_REG_DW 0x06
34 #define PCF8563_REG_MO 0x07
35 #define PCF8563_REG_YR 0x08
36
37 #define PCF8563_REG_AMN 0x09 /* alarm */
38
39 #define PCF8563_REG_CLKO 0x0D /* clock out */
40 #define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
41 #define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
42 #define PCF8563_REG_CLKO_F_32768HZ 0x00
43 #define PCF8563_REG_CLKO_F_1024HZ 0x01
44 #define PCF8563_REG_CLKO_F_32HZ 0x02
45 #define PCF8563_REG_CLKO_F_1HZ 0x03
46
47 #define PCF8563_REG_TMRC 0x0E /* timer control */
48 #define PCF8563_TMRC_ENABLE BIT(7)
49 #define PCF8563_TMRC_4096 0
50 #define PCF8563_TMRC_64 1
51 #define PCF8563_TMRC_1 2
52 #define PCF8563_TMRC_1_60 3
53 #define PCF8563_TMRC_MASK 3
54
55 #define PCF8563_REG_TMR 0x0F /* timer */
56
57 #define PCF8563_SC_LV 0x80 /* low voltage */
58 #define PCF8563_MO_C 0x80 /* century */
59
60 static struct i2c_driver pcf8563_driver;
61
62 struct pcf8563 {
63 struct rtc_device *rtc;
64 /*
65 * The meaning of MO_C bit varies by the chip type.
66 * From PCF8563 datasheet: this bit is toggled when the years
67 * register overflows from 99 to 00
68 * 0 indicates the century is 20xx
69 * 1 indicates the century is 19xx
70 * From RTC8564 datasheet: this bit indicates change of
71 * century. When the year digit data overflows from 99 to 00,
72 * this bit is set. By presetting it to 0 while still in the
73 * 20th century, it will be set in year 2000, ...
74 * There seems no reliable way to know how the system use this
75 * bit. So let's do it heuristically, assuming we are live in
76 * 1970...2069.
77 */
78 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
79
80 struct i2c_client *client;
81 #ifdef CONFIG_COMMON_CLK
82 struct clk_hw clkout_hw;
83 #endif
84 };
85
86 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
87 unsigned char length, unsigned char *buf)
88 {
89 struct i2c_msg msgs[] = {
90 {/* setup read ptr */
91 .addr = client->addr,
92 .len = 1,
93 .buf = &reg,
94 },
95 {
96 .addr = client->addr,
97 .flags = I2C_M_RD,
98 .len = length,
99 .buf = buf
100 },
101 };
102
103 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
104 dev_err(&client->dev, "%s: read error\n", __func__);
105 return -EIO;
106 }
107
108 return 0;
109 }
110
111 static int pcf8563_write_block_data(struct i2c_client *client,
112 unsigned char reg, unsigned char length,
113 unsigned char *buf)
114 {
115 int i, err;
116
117 for (i = 0; i < length; i++) {
118 unsigned char data[2] = { reg + i, buf[i] };
119
120 err = i2c_master_send(client, data, sizeof(data));
121 if (err != sizeof(data)) {
122 dev_err(&client->dev,
123 "%s: err=%d addr=%02x, data=%02x\n",
124 __func__, err, data[0], data[1]);
125 return -EIO;
126 }
127 }
128
129 return 0;
130 }
131
132 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
133 {
134 unsigned char buf;
135 int err;
136
137 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
138 if (err < 0)
139 return err;
140
141 if (on)
142 buf |= PCF8563_BIT_AIE;
143 else
144 buf &= ~PCF8563_BIT_AIE;
145
146 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
147
148 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
149 if (err < 0) {
150 dev_err(&client->dev, "%s: write error\n", __func__);
151 return -EIO;
152 }
153
154 return 0;
155 }
156
157 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
158 unsigned char *pen)
159 {
160 unsigned char buf;
161 int err;
162
163 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
164 if (err)
165 return err;
166
167 if (en)
168 *en = !!(buf & PCF8563_BIT_AIE);
169 if (pen)
170 *pen = !!(buf & PCF8563_BIT_AF);
171
172 return 0;
173 }
174
175 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
176 {
177 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
178 int err;
179 char pending;
180
181 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
182 if (err)
183 return IRQ_NONE;
184
185 if (pending) {
186 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
187 pcf8563_set_alarm_mode(pcf8563->client, 1);
188 return IRQ_HANDLED;
189 }
190
191 return IRQ_NONE;
192 }
193
194 /*
195 * In the routines that deal directly with the pcf8563 hardware, we use
196 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
197 */
198 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
199 {
200 struct i2c_client *client = to_i2c_client(dev);
201 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
202 unsigned char buf[9];
203 int err;
204
205 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
206 if (err)
207 return err;
208
209 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
210 dev_err(&client->dev,
211 "low voltage detected, date/time is not reliable.\n");
212 return -EINVAL;
213 }
214
215 dev_dbg(&client->dev,
216 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
217 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
218 __func__,
219 buf[0], buf[1], buf[2], buf[3],
220 buf[4], buf[5], buf[6], buf[7],
221 buf[8]);
222
223
224 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
225 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
226 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
227 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
228 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
229 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
230 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
231 /* detect the polarity heuristically. see note above. */
232 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
233 (tm->tm_year >= 100) : (tm->tm_year < 100);
234
235 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
236 "mday=%d, mon=%d, year=%d, wday=%d\n",
237 __func__,
238 tm->tm_sec, tm->tm_min, tm->tm_hour,
239 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
240
241 return 0;
242 }
243
244 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
245 {
246 struct i2c_client *client = to_i2c_client(dev);
247 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
248 unsigned char buf[9];
249
250 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
251 "mday=%d, mon=%d, year=%d, wday=%d\n",
252 __func__,
253 tm->tm_sec, tm->tm_min, tm->tm_hour,
254 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
255
256 /* hours, minutes and seconds */
257 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
258 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
259 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
260
261 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
262
263 /* month, 1 - 12 */
264 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
265
266 /* year and century */
267 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
268 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
269 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
270
271 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
272
273 return pcf8563_write_block_data(client, PCF8563_REG_SC,
274 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
275 }
276
277 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
278 {
279 struct i2c_client *client = to_i2c_client(dev);
280 int ret;
281
282 switch (cmd) {
283 case RTC_VL_READ:
284 ret = i2c_smbus_read_byte_data(client, PCF8563_REG_SC);
285 if (ret < 0)
286 return ret;
287
288 return put_user(ret & PCF8563_SC_LV ? RTC_VL_DATA_INVALID : 0,
289 (unsigned int __user *)arg);
290 default:
291 return -ENOIOCTLCMD;
292 }
293 }
294
295 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
296 {
297 struct i2c_client *client = to_i2c_client(dev);
298 unsigned char buf[4];
299 int err;
300
301 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
302 if (err)
303 return err;
304
305 dev_dbg(&client->dev,
306 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
307 __func__, buf[0], buf[1], buf[2], buf[3]);
308
309 tm->time.tm_sec = 0;
310 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
311 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
312 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
313 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
314
315 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
316 if (err < 0)
317 return err;
318
319 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
320 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
321 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
322 tm->enabled, tm->pending);
323
324 return 0;
325 }
326
327 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
328 {
329 struct i2c_client *client = to_i2c_client(dev);
330 unsigned char buf[4];
331 int err;
332
333 /* The alarm has no seconds, round up to nearest minute */
334 if (tm->time.tm_sec) {
335 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
336
337 alarm_time += 60 - tm->time.tm_sec;
338 rtc_time64_to_tm(alarm_time, &tm->time);
339 }
340
341 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
342 "enabled=%d pending=%d\n", __func__,
343 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
344 tm->time.tm_mday, tm->enabled, tm->pending);
345
346 buf[0] = bin2bcd(tm->time.tm_min);
347 buf[1] = bin2bcd(tm->time.tm_hour);
348 buf[2] = bin2bcd(tm->time.tm_mday);
349 buf[3] = tm->time.tm_wday & 0x07;
350
351 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
352 if (err)
353 return err;
354
355 return pcf8563_set_alarm_mode(client, !!tm->enabled);
356 }
357
358 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
359 {
360 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
361 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
362 }
363
364 #ifdef CONFIG_COMMON_CLK
365 /*
366 * Handling of the clkout
367 */
368
369 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
370
371 static const int clkout_rates[] = {
372 32768,
373 1024,
374 32,
375 1,
376 };
377
378 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
379 unsigned long parent_rate)
380 {
381 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
382 struct i2c_client *client = pcf8563->client;
383 unsigned char buf;
384 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
385
386 if (ret < 0)
387 return 0;
388
389 buf &= PCF8563_REG_CLKO_F_MASK;
390 return clkout_rates[buf];
391 }
392
393 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
394 unsigned long *prate)
395 {
396 int i;
397
398 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
399 if (clkout_rates[i] <= rate)
400 return clkout_rates[i];
401
402 return 0;
403 }
404
405 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
406 unsigned long parent_rate)
407 {
408 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
409 struct i2c_client *client = pcf8563->client;
410 unsigned char buf;
411 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
412 int i;
413
414 if (ret < 0)
415 return ret;
416
417 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
418 if (clkout_rates[i] == rate) {
419 buf &= ~PCF8563_REG_CLKO_F_MASK;
420 buf |= i;
421 ret = pcf8563_write_block_data(client,
422 PCF8563_REG_CLKO, 1,
423 &buf);
424 return ret;
425 }
426
427 return -EINVAL;
428 }
429
430 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
431 {
432 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
433 struct i2c_client *client = pcf8563->client;
434 unsigned char buf;
435 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
436
437 if (ret < 0)
438 return ret;
439
440 if (enable)
441 buf |= PCF8563_REG_CLKO_FE;
442 else
443 buf &= ~PCF8563_REG_CLKO_FE;
444
445 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
446 return ret;
447 }
448
449 static int pcf8563_clkout_prepare(struct clk_hw *hw)
450 {
451 return pcf8563_clkout_control(hw, 1);
452 }
453
454 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
455 {
456 pcf8563_clkout_control(hw, 0);
457 }
458
459 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
460 {
461 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
462 struct i2c_client *client = pcf8563->client;
463 unsigned char buf;
464 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
465
466 if (ret < 0)
467 return ret;
468
469 return !!(buf & PCF8563_REG_CLKO_FE);
470 }
471
472 static const struct clk_ops pcf8563_clkout_ops = {
473 .prepare = pcf8563_clkout_prepare,
474 .unprepare = pcf8563_clkout_unprepare,
475 .is_prepared = pcf8563_clkout_is_prepared,
476 .recalc_rate = pcf8563_clkout_recalc_rate,
477 .round_rate = pcf8563_clkout_round_rate,
478 .set_rate = pcf8563_clkout_set_rate,
479 };
480
481 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
482 {
483 struct i2c_client *client = pcf8563->client;
484 struct device_node *node = client->dev.of_node;
485 struct clk *clk;
486 struct clk_init_data init;
487 int ret;
488 unsigned char buf;
489
490 /* disable the clkout output */
491 buf = 0;
492 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
493 if (ret < 0)
494 return ERR_PTR(ret);
495
496 init.name = "pcf8563-clkout";
497 init.ops = &pcf8563_clkout_ops;
498 init.flags = 0;
499 init.parent_names = NULL;
500 init.num_parents = 0;
501 pcf8563->clkout_hw.init = &init;
502
503 /* optional override of the clockname */
504 of_property_read_string(node, "clock-output-names", &init.name);
505
506 /* register the clock */
507 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
508
509 if (!IS_ERR(clk))
510 of_clk_add_provider(node, of_clk_src_simple_get, clk);
511
512 return clk;
513 }
514 #endif
515
516 static const struct rtc_class_ops pcf8563_rtc_ops = {
517 .ioctl = pcf8563_rtc_ioctl,
518 .read_time = pcf8563_rtc_read_time,
519 .set_time = pcf8563_rtc_set_time,
520 .read_alarm = pcf8563_rtc_read_alarm,
521 .set_alarm = pcf8563_rtc_set_alarm,
522 .alarm_irq_enable = pcf8563_irq_enable,
523 };
524
525 static int pcf8563_probe(struct i2c_client *client,
526 const struct i2c_device_id *id)
527 {
528 struct pcf8563 *pcf8563;
529 int err;
530 unsigned char buf;
531
532 dev_dbg(&client->dev, "%s\n", __func__);
533
534 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
535 return -ENODEV;
536
537 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
538 GFP_KERNEL);
539 if (!pcf8563)
540 return -ENOMEM;
541
542 i2c_set_clientdata(client, pcf8563);
543 pcf8563->client = client;
544 device_set_wakeup_capable(&client->dev, 1);
545
546 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
547 buf = PCF8563_TMRC_1_60;
548 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
549 if (err < 0) {
550 dev_err(&client->dev, "%s: write error\n", __func__);
551 return err;
552 }
553
554 /* Clear flags and disable interrupts */
555 buf = 0;
556 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
557 if (err < 0) {
558 dev_err(&client->dev, "%s: write error\n", __func__);
559 return err;
560 }
561
562 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
563 if (IS_ERR(pcf8563->rtc))
564 return PTR_ERR(pcf8563->rtc);
565
566 pcf8563->rtc->ops = &pcf8563_rtc_ops;
567 /* the pcf8563 alarm only supports a minute accuracy */
568 pcf8563->rtc->uie_unsupported = 1;
569 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
570 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
571 pcf8563->rtc->set_start_time = true;
572
573 if (client->irq > 0) {
574 err = devm_request_threaded_irq(&client->dev, client->irq,
575 NULL, pcf8563_irq,
576 IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
577 pcf8563_driver.driver.name, client);
578 if (err) {
579 dev_err(&client->dev, "unable to request IRQ %d\n",
580 client->irq);
581 return err;
582 }
583 }
584
585 err = devm_rtc_register_device(pcf8563->rtc);
586 if (err)
587 return err;
588
589 #ifdef CONFIG_COMMON_CLK
590 /* register clk in common clk framework */
591 pcf8563_clkout_register_clk(pcf8563);
592 #endif
593
594 return 0;
595 }
596
597 static const struct i2c_device_id pcf8563_id[] = {
598 { "pcf8563", 0 },
599 { "rtc8564", 0 },
600 { "pca8565", 0 },
601 { }
602 };
603 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
604
605 #ifdef CONFIG_OF
606 static const struct of_device_id pcf8563_of_match[] = {
607 { .compatible = "nxp,pcf8563" },
608 { .compatible = "epson,rtc8564" },
609 { .compatible = "microcrystal,rv8564" },
610 { .compatible = "nxp,pca8565" },
611 {}
612 };
613 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
614 #endif
615
616 static struct i2c_driver pcf8563_driver = {
617 .driver = {
618 .name = "rtc-pcf8563",
619 .of_match_table = of_match_ptr(pcf8563_of_match),
620 },
621 .probe = pcf8563_probe,
622 .id_table = pcf8563_id,
623 };
624
625 module_i2c_driver(pcf8563_driver);
626
627 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
628 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
629 MODULE_LICENSE("GPL");