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 * https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf
12 */
13
14#include <linux/bcd.h>
15#include <linux/clk-provider.h>
16#include <linux/err.h>
17#include <linux/i2c.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/regmap.h>
21#include <linux/rtc.h>
22#include <linux/slab.h>
23
24#define PCF8563_REG_ST1 0x00 /* status */
25#define PCF8563_REG_ST2 0x01
26#define PCF8563_BIT_AIE BIT(1)
27#define PCF8563_BIT_AF BIT(3)
28#define PCF8563_BITS_ST2_N (7 << 5)
29
30#define PCF8563_REG_SC 0x02 /* datetime */
31#define PCF8563_REG_MN 0x03
32#define PCF8563_REG_HR 0x04
33#define PCF8563_REG_DM 0x05
34#define PCF8563_REG_DW 0x06
35#define PCF8563_REG_MO 0x07
36#define PCF8563_REG_YR 0x08
37
38#define PCF8563_REG_AMN 0x09 /* alarm */
39
40#define PCF8563_REG_CLKO 0x0D /* clock out */
41#define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
42#define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
43#define PCF8563_REG_CLKO_F_32768HZ 0x00
44#define PCF8563_REG_CLKO_F_1024HZ 0x01
45#define PCF8563_REG_CLKO_F_32HZ 0x02
46#define PCF8563_REG_CLKO_F_1HZ 0x03
47
48#define PCF8563_REG_TMRC 0x0E /* timer control */
49#define PCF8563_TMRC_ENABLE BIT(7)
50#define PCF8563_TMRC_4096 0
51#define PCF8563_TMRC_64 1
52#define PCF8563_TMRC_1 2
53#define PCF8563_TMRC_1_60 3
54#define PCF8563_TMRC_MASK 3
55
56#define PCF8563_REG_TMR 0x0F /* timer */
57
58#define PCF8563_SC_LV 0x80 /* low voltage */
59#define PCF8563_MO_C 0x80 /* century */
60
61static struct i2c_driver pcf8563_driver;
62
63struct pcf8563 {
64 struct rtc_device *rtc;
65 /*
66 * The meaning of MO_C bit varies by the chip type.
67 * From PCF8563 datasheet: this bit is toggled when the years
68 * register overflows from 99 to 00
69 * 0 indicates the century is 20xx
70 * 1 indicates the century is 19xx
71 * From RTC8564 datasheet: this bit indicates change of
72 * century. When the year digit data overflows from 99 to 00,
73 * this bit is set. By presetting it to 0 while still in the
74 * 20th century, it will be set in year 2000, ...
75 * There seems no reliable way to know how the system use this
76 * bit. So let's do it heuristically, assuming we are live in
77 * 1970...2069.
78 */
79 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
80
81 struct regmap *regmap;
82#ifdef CONFIG_COMMON_CLK
83 struct clk_hw clkout_hw;
84#endif
85};
86
87static int pcf8563_set_alarm_mode(struct pcf8563 *pcf8563, bool on)
88{
89 u32 buf;
90 int err;
91
92 err = regmap_read(map: pcf8563->regmap, PCF8563_REG_ST2, val: &buf);
93 if (err < 0)
94 return err;
95
96 if (on)
97 buf |= PCF8563_BIT_AIE;
98 else
99 buf &= ~PCF8563_BIT_AIE;
100
101 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
102
103 return regmap_write(map: pcf8563->regmap, PCF8563_REG_ST2, val: buf);
104}
105
106static int pcf8563_get_alarm_mode(struct pcf8563 *pcf8563, unsigned char *en,
107 unsigned char *pen)
108{
109 u32 buf;
110 int err;
111
112 err = regmap_read(map: pcf8563->regmap, PCF8563_REG_ST2, val: &buf);
113 if (err < 0)
114 return err;
115
116 if (en)
117 *en = !!(buf & PCF8563_BIT_AIE);
118 if (pen)
119 *pen = !!(buf & PCF8563_BIT_AF);
120
121 return 0;
122}
123
124static irqreturn_t pcf8563_irq(int irq, void *dev_id)
125{
126 struct pcf8563 *pcf8563 = dev_id;
127 char pending;
128 int err;
129
130 err = pcf8563_get_alarm_mode(pcf8563, NULL, pen: &pending);
131 if (err)
132 return IRQ_NONE;
133
134 if (pending) {
135 rtc_update_irq(rtc: pcf8563->rtc, num: 1, RTC_IRQF | RTC_AF);
136 pcf8563_set_alarm_mode(pcf8563, on: 1);
137 return IRQ_HANDLED;
138 }
139
140 return IRQ_NONE;
141}
142
143/*
144 * In the routines that deal directly with the pcf8563 hardware, we use
145 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
146 */
147static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
148{
149 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
150 unsigned char buf[9];
151 int err;
152
153 err = regmap_bulk_read(map: pcf8563->regmap, PCF8563_REG_ST1, val: buf,
154 val_count: sizeof(buf));
155 if (err < 0)
156 return err;
157
158 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
159 dev_err(dev,
160 "low voltage detected, date/time is not reliable.\n");
161 return -EINVAL;
162 }
163
164 dev_dbg(dev,
165 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
166 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
167 __func__,
168 buf[0], buf[1], buf[2], buf[3],
169 buf[4], buf[5], buf[6], buf[7],
170 buf[8]);
171
172 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
173 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
174 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
175 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
176 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
177 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
178 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
179 /* detect the polarity heuristically. see note above. */
180 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
181 (tm->tm_year >= 100) : (tm->tm_year < 100);
182
183 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
184 "mday=%d, mon=%d, year=%d, wday=%d\n",
185 __func__,
186 tm->tm_sec, tm->tm_min, tm->tm_hour,
187 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
188
189 return 0;
190}
191
192static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
193{
194 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
195 unsigned char buf[9];
196
197 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
198 "mday=%d, mon=%d, year=%d, wday=%d\n",
199 __func__,
200 tm->tm_sec, tm->tm_min, tm->tm_hour,
201 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
202
203 /* hours, minutes and seconds */
204 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
205 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
206 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
207
208 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
209
210 /* month, 1 - 12 */
211 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
212
213 /* year and century */
214 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
215 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
216 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
217
218 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
219
220 return regmap_bulk_write(map: pcf8563->regmap, PCF8563_REG_SC,
221 val: buf + PCF8563_REG_SC,
222 val_count: sizeof(buf) - PCF8563_REG_SC);
223}
224
225static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
226{
227 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
228 int ret;
229
230 switch (cmd) {
231 case RTC_VL_READ:
232 ret = regmap_test_bits(map: pcf8563->regmap, PCF8563_REG_SC,
233 PCF8563_SC_LV);
234 if (ret < 0)
235 return ret;
236
237 return put_user(ret ? RTC_VL_DATA_INVALID : 0,
238 (unsigned int __user *)arg);
239 default:
240 return -ENOIOCTLCMD;
241 }
242}
243
244static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
245{
246 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
247 unsigned char buf[4];
248 int err;
249
250 err = regmap_bulk_read(map: pcf8563->regmap, PCF8563_REG_AMN, val: buf,
251 val_count: sizeof(buf));
252 if (err < 0)
253 return err;
254
255 dev_dbg(dev,
256 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
257 __func__, buf[0], buf[1], buf[2], buf[3]);
258
259 tm->time.tm_sec = 0;
260 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
261 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
262 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
263 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
264
265 err = pcf8563_get_alarm_mode(pcf8563, en: &tm->enabled, pen: &tm->pending);
266 if (err < 0)
267 return err;
268
269 dev_dbg(dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
270 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
271 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
272 tm->enabled, tm->pending);
273
274 return 0;
275}
276
277static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
278{
279 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
280 unsigned char buf[4];
281 int err;
282
283 buf[0] = bin2bcd(tm->time.tm_min);
284 buf[1] = bin2bcd(tm->time.tm_hour);
285 buf[2] = bin2bcd(tm->time.tm_mday);
286 buf[3] = tm->time.tm_wday & 0x07;
287
288 err = regmap_bulk_write(map: pcf8563->regmap, PCF8563_REG_AMN, val: buf,
289 val_count: sizeof(buf));
290 if (err)
291 return err;
292
293 return pcf8563_set_alarm_mode(pcf8563, on: !!tm->enabled);
294}
295
296static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
297{
298 struct pcf8563 *pcf8563 = dev_get_drvdata(dev);
299
300 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
301 return pcf8563_set_alarm_mode(pcf8563, on: !!enabled);
302}
303
304#ifdef CONFIG_COMMON_CLK
305/*
306 * Handling of the clkout
307 */
308
309#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
310
311static const int clkout_rates[] = {
312 32768,
313 1024,
314 32,
315 1,
316};
317
318static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
319 unsigned long parent_rate)
320{
321 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
322 u32 buf;
323 int ret;
324
325 ret = regmap_read(map: pcf8563->regmap, PCF8563_REG_CLKO, val: &buf);
326 if (ret < 0)
327 return 0;
328
329 buf &= PCF8563_REG_CLKO_F_MASK;
330 return clkout_rates[buf];
331}
332
333static int pcf8563_clkout_determine_rate(struct clk_hw *hw,
334 struct clk_rate_request *req)
335{
336 int i;
337
338 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
339 if (clkout_rates[i] <= req->rate) {
340 req->rate = clkout_rates[i];
341
342 return 0;
343 }
344
345 req->rate = clkout_rates[0];
346
347 return 0;
348}
349
350static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
351 unsigned long parent_rate)
352{
353 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
354 int i, ret;
355 u32 buf;
356
357 ret = regmap_read(map: pcf8563->regmap, PCF8563_REG_CLKO, val: &buf);
358 if (ret < 0)
359 return ret;
360
361 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
362 if (clkout_rates[i] == rate) {
363 buf &= ~PCF8563_REG_CLKO_F_MASK;
364 buf |= i;
365 return regmap_update_bits(map: pcf8563->regmap,
366 PCF8563_REG_CLKO,
367 PCF8563_REG_CLKO_F_MASK,
368 val: buf);
369 }
370
371 return -EINVAL;
372}
373
374static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
375{
376 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
377 u32 buf;
378 int ret;
379
380 ret = regmap_read(map: pcf8563->regmap, PCF8563_REG_CLKO, val: &buf);
381 if (ret < 0)
382 return ret;
383
384 if (enable)
385 buf |= PCF8563_REG_CLKO_FE;
386 else
387 buf &= ~PCF8563_REG_CLKO_FE;
388
389 return regmap_update_bits(map: pcf8563->regmap, PCF8563_REG_CLKO,
390 PCF8563_REG_CLKO_FE, val: buf);
391}
392
393static int pcf8563_clkout_prepare(struct clk_hw *hw)
394{
395 return pcf8563_clkout_control(hw, enable: 1);
396}
397
398static void pcf8563_clkout_unprepare(struct clk_hw *hw)
399{
400 pcf8563_clkout_control(hw, enable: 0);
401}
402
403static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
404{
405 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
406 u32 buf;
407 int ret;
408
409 ret = regmap_read(map: pcf8563->regmap, PCF8563_REG_CLKO, val: &buf);
410 if (ret < 0)
411 return ret;
412
413 return !!(buf & PCF8563_REG_CLKO_FE);
414}
415
416static const struct clk_ops pcf8563_clkout_ops = {
417 .prepare = pcf8563_clkout_prepare,
418 .unprepare = pcf8563_clkout_unprepare,
419 .is_prepared = pcf8563_clkout_is_prepared,
420 .recalc_rate = pcf8563_clkout_recalc_rate,
421 .determine_rate = pcf8563_clkout_determine_rate,
422 .set_rate = pcf8563_clkout_set_rate,
423};
424
425static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
426{
427 struct device_node *node = pcf8563->rtc->dev.of_node;
428 struct clk_init_data init;
429 struct clk *clk;
430 int ret;
431
432 /* disable the clkout output */
433 ret = regmap_clear_bits(map: pcf8563->regmap, PCF8563_REG_CLKO,
434 PCF8563_REG_CLKO_FE);
435 if (ret < 0)
436 return ERR_PTR(error: ret);
437
438 init.name = "pcf8563-clkout";
439 init.ops = &pcf8563_clkout_ops;
440 init.flags = 0;
441 init.parent_names = NULL;
442 init.num_parents = 0;
443 pcf8563->clkout_hw.init = &init;
444
445 /* optional override of the clockname */
446 of_property_read_string(np: node, propname: "clock-output-names", out_string: &init.name);
447
448 /* register the clock */
449 clk = devm_clk_register(dev: &pcf8563->rtc->dev, hw: &pcf8563->clkout_hw);
450
451 if (!IS_ERR(ptr: clk))
452 of_clk_add_provider(np: node, clk_src_get: of_clk_src_simple_get, data: clk);
453
454 return clk;
455}
456#endif
457
458static const struct rtc_class_ops pcf8563_rtc_ops = {
459 .ioctl = pcf8563_rtc_ioctl,
460 .read_time = pcf8563_rtc_read_time,
461 .set_time = pcf8563_rtc_set_time,
462 .read_alarm = pcf8563_rtc_read_alarm,
463 .set_alarm = pcf8563_rtc_set_alarm,
464 .alarm_irq_enable = pcf8563_irq_enable,
465};
466
467static const struct regmap_config regmap_config = {
468 .reg_bits = 8,
469 .val_bits = 8,
470 .max_register = 0xF,
471};
472
473static int pcf8563_probe(struct i2c_client *client)
474{
475 struct pcf8563 *pcf8563;
476 int err;
477
478 dev_dbg(&client->dev, "%s\n", __func__);
479
480 if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_I2C))
481 return -ENODEV;
482
483 pcf8563 = devm_kzalloc(dev: &client->dev, size: sizeof(struct pcf8563),
484 GFP_KERNEL);
485 if (!pcf8563)
486 return -ENOMEM;
487
488 pcf8563->regmap = devm_regmap_init_i2c(client, &regmap_config);
489 if (IS_ERR(ptr: pcf8563->regmap))
490 return PTR_ERR(ptr: pcf8563->regmap);
491
492 i2c_set_clientdata(client, data: pcf8563);
493 device_set_wakeup_capable(dev: &client->dev, capable: 1);
494
495 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
496 err = regmap_set_bits(map: pcf8563->regmap, PCF8563_REG_TMRC,
497 PCF8563_TMRC_1_60);
498 if (err < 0) {
499 dev_err(&client->dev, "%s: write error\n", __func__);
500 return err;
501 }
502
503 /* Clear flags and disable interrupts */
504 err = regmap_write(map: pcf8563->regmap, PCF8563_REG_ST2, val: 0);
505 if (err < 0) {
506 dev_err(&client->dev, "%s: write error\n", __func__);
507 return err;
508 }
509
510 pcf8563->rtc = devm_rtc_allocate_device(dev: &client->dev);
511 if (IS_ERR(ptr: pcf8563->rtc))
512 return PTR_ERR(ptr: pcf8563->rtc);
513
514 pcf8563->rtc->ops = &pcf8563_rtc_ops;
515 /* the pcf8563 alarm only supports a minute accuracy */
516 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, addr: pcf8563->rtc->features);
517 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, addr: pcf8563->rtc->features);
518 clear_bit(RTC_FEATURE_ALARM, addr: pcf8563->rtc->features);
519 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
520 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
521 pcf8563->rtc->set_start_time = true;
522
523 if (client->irq > 0) {
524 unsigned long irqflags = IRQF_TRIGGER_LOW;
525
526 if (dev_fwnode(&client->dev))
527 irqflags = 0;
528
529 err = devm_request_threaded_irq(dev: &client->dev, irq: client->irq,
530 NULL, thread_fn: pcf8563_irq,
531 IRQF_SHARED | IRQF_ONESHOT | irqflags,
532 devname: pcf8563_driver.driver.name, dev_id: client);
533 if (err) {
534 dev_err(&client->dev, "unable to request IRQ %d\n",
535 client->irq);
536 return err;
537 }
538 } else {
539 client->irq = 0;
540 }
541
542 if (client->irq > 0 || device_property_read_bool(dev: &client->dev, propname: "wakeup-source")) {
543 device_init_wakeup(dev: &client->dev, enable: true);
544 set_bit(RTC_FEATURE_ALARM, addr: pcf8563->rtc->features);
545 }
546
547 err = devm_rtc_register_device(pcf8563->rtc);
548 if (err)
549 return err;
550
551#ifdef CONFIG_COMMON_CLK
552 /* register clk in common clk framework */
553 pcf8563_clkout_register_clk(pcf8563);
554#endif
555
556 return 0;
557}
558
559static const struct i2c_device_id pcf8563_id[] = {
560 { "pcf8563" },
561 { "rtc8564" },
562 { "pca8565" },
563 { }
564};
565MODULE_DEVICE_TABLE(i2c, pcf8563_id);
566
567#ifdef CONFIG_OF
568static const struct of_device_id pcf8563_of_match[] = {
569 { .compatible = "nxp,pcf8563" },
570 { .compatible = "epson,rtc8564" },
571 { .compatible = "microcrystal,rv8564" },
572 { .compatible = "nxp,pca8565" },
573 {}
574};
575MODULE_DEVICE_TABLE(of, pcf8563_of_match);
576#endif
577
578static struct i2c_driver pcf8563_driver = {
579 .driver = {
580 .name = "rtc-pcf8563",
581 .of_match_table = of_match_ptr(pcf8563_of_match),
582 },
583 .probe = pcf8563_probe,
584 .id_table = pcf8563_id,
585};
586
587module_i2c_driver(pcf8563_driver);
588
589MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
590MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
591MODULE_LICENSE("GPL");
592

source code of linux/drivers/rtc/rtc-pcf8563.c