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1/*
2 * An I2C driver for the Philips PCF8563 RTC
3 * Copyright 2005-06 Tower Technologies
4 *
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 * Maintainers: http://www.nslu2-linux.org/
7 *
8 * based on the other drivers in this same directory.
9 *
10 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/clk-provider.h>
18#include <linux/i2c.h>
19#include <linux/bcd.h>
20#include <linux/rtc.h>
21#include <linux/slab.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/err.h>
25
26#define PCF8563_REG_ST1 0x00 /* status */
27#define PCF8563_REG_ST2 0x01
28#define PCF8563_BIT_AIE (1 << 1)
29#define PCF8563_BIT_AF (1 << 3)
30#define PCF8563_BITS_ST2_N (7 << 5)
31
32#define PCF8563_REG_SC 0x02 /* datetime */
33#define PCF8563_REG_MN 0x03
34#define PCF8563_REG_HR 0x04
35#define PCF8563_REG_DM 0x05
36#define PCF8563_REG_DW 0x06
37#define PCF8563_REG_MO 0x07
38#define PCF8563_REG_YR 0x08
39
40#define PCF8563_REG_AMN 0x09 /* alarm */
41
42#define PCF8563_REG_CLKO 0x0D /* clock out */
43#define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
44#define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
45#define PCF8563_REG_CLKO_F_32768HZ 0x00
46#define PCF8563_REG_CLKO_F_1024HZ 0x01
47#define PCF8563_REG_CLKO_F_32HZ 0x02
48#define PCF8563_REG_CLKO_F_1HZ 0x03
49
50#define PCF8563_REG_TMRC 0x0E /* timer control */
51#define PCF8563_TMRC_ENABLE BIT(7)
52#define PCF8563_TMRC_4096 0
53#define PCF8563_TMRC_64 1
54#define PCF8563_TMRC_1 2
55#define PCF8563_TMRC_1_60 3
56#define PCF8563_TMRC_MASK 3
57
58#define PCF8563_REG_TMR 0x0F /* timer */
59
60#define PCF8563_SC_LV 0x80 /* low voltage */
61#define PCF8563_MO_C 0x80 /* century */
62
63static struct i2c_driver pcf8563_driver;
64
65struct pcf8563 {
66 struct rtc_device *rtc;
67 /*
68 * The meaning of MO_C bit varies by the chip type.
69 * From PCF8563 datasheet: this bit is toggled when the years
70 * register overflows from 99 to 00
71 * 0 indicates the century is 20xx
72 * 1 indicates the century is 19xx
73 * From RTC8564 datasheet: this bit indicates change of
74 * century. When the year digit data overflows from 99 to 00,
75 * this bit is set. By presetting it to 0 while still in the
76 * 20th century, it will be set in year 2000, ...
77 * There seems no reliable way to know how the system use this
78 * bit. So let's do it heuristically, assuming we are live in
79 * 1970...2069.
80 */
81 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
82 int voltage_low; /* incicates if a low_voltage was detected */
83
84 struct i2c_client *client;
85#ifdef CONFIG_COMMON_CLK
86 struct clk_hw clkout_hw;
87#endif
88};
89
90static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
91 unsigned char length, unsigned char *buf)
92{
93 struct i2c_msg msgs[] = {
94 {/* setup read ptr */
95 .addr = client->addr,
96 .len = 1,
97 .buf = ®,
98 },
99 {
100 .addr = client->addr,
101 .flags = I2C_M_RD,
102 .len = length,
103 .buf = buf
104 },
105 };
106
107 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
108 dev_err(&client->dev, "%s: read error\n", __func__);
109 return -EIO;
110 }
111
112 return 0;
113}
114
115static int pcf8563_write_block_data(struct i2c_client *client,
116 unsigned char reg, unsigned char length,
117 unsigned char *buf)
118{
119 int i, err;
120
121 for (i = 0; i < length; i++) {
122 unsigned char data[2] = { reg + i, buf[i] };
123
124 err = i2c_master_send(client, data, sizeof(data));
125 if (err != sizeof(data)) {
126 dev_err(&client->dev,
127 "%s: err=%d addr=%02x, data=%02x\n",
128 __func__, err, data[0], data[1]);
129 return -EIO;
130 }
131 }
132
133 return 0;
134}
135
136static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
137{
138 unsigned char buf;
139 int err;
140
141 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
142 if (err < 0)
143 return err;
144
145 if (on)
146 buf |= PCF8563_BIT_AIE;
147 else
148 buf &= ~PCF8563_BIT_AIE;
149
150 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
151
152 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
153 if (err < 0) {
154 dev_err(&client->dev, "%s: write error\n", __func__);
155 return -EIO;
156 }
157
158 return 0;
159}
160
161static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
162 unsigned char *pen)
163{
164 unsigned char buf;
165 int err;
166
167 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
168 if (err)
169 return err;
170
171 if (en)
172 *en = !!(buf & PCF8563_BIT_AIE);
173 if (pen)
174 *pen = !!(buf & PCF8563_BIT_AF);
175
176 return 0;
177}
178
179static irqreturn_t pcf8563_irq(int irq, void *dev_id)
180{
181 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
182 int err;
183 char pending;
184
185 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
186 if (err)
187 return IRQ_NONE;
188
189 if (pending) {
190 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
191 pcf8563_set_alarm_mode(pcf8563->client, 1);
192 return IRQ_HANDLED;
193 }
194
195 return IRQ_NONE;
196}
197
198/*
199 * In the routines that deal directly with the pcf8563 hardware, we use
200 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
201 */
202static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
203{
204 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
205 unsigned char buf[9];
206 int err;
207
208 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
209 if (err)
210 return err;
211
212 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
213 pcf8563->voltage_low = 1;
214 dev_err(&client->dev,
215 "low voltage detected, date/time is not reliable.\n");
216 return -EINVAL;
217 }
218
219 dev_dbg(&client->dev,
220 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
221 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
222 __func__,
223 buf[0], buf[1], buf[2], buf[3],
224 buf[4], buf[5], buf[6], buf[7],
225 buf[8]);
226
227
228 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
229 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
230 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
231 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
232 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
233 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
234 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
235 if (tm->tm_year < 70)
236 tm->tm_year += 100; /* assume we are in 1970...2069 */
237 /* detect the polarity heuristically. see note above. */
238 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
239 (tm->tm_year >= 100) : (tm->tm_year < 100);
240
241 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
242 "mday=%d, mon=%d, year=%d, wday=%d\n",
243 __func__,
244 tm->tm_sec, tm->tm_min, tm->tm_hour,
245 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
246
247 return 0;
248}
249
250static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
251{
252 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
253 unsigned char buf[9];
254
255 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
256 "mday=%d, mon=%d, year=%d, wday=%d\n",
257 __func__,
258 tm->tm_sec, tm->tm_min, tm->tm_hour,
259 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
260
261 /* hours, minutes and seconds */
262 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
263 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
264 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
265
266 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
267
268 /* month, 1 - 12 */
269 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
270
271 /* year and century */
272 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
273 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
274 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
275
276 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
277
278 return pcf8563_write_block_data(client, PCF8563_REG_SC,
279 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
280}
281
282#ifdef CONFIG_RTC_INTF_DEV
283static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
284{
285 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
286 struct rtc_time tm;
287
288 switch (cmd) {
289 case RTC_VL_READ:
290 if (pcf8563->voltage_low)
291 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
292
293 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
294 sizeof(int)))
295 return -EFAULT;
296 return 0;
297 case RTC_VL_CLR:
298 /*
299 * Clear the VL bit in the seconds register in case
300 * the time has not been set already (which would
301 * have cleared it). This does not really matter
302 * because of the cached voltage_low value but do it
303 * anyway for consistency.
304 */
305 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
306 pcf8563_set_datetime(to_i2c_client(dev), &tm);
307
308 /* Clear the cached value. */
309 pcf8563->voltage_low = 0;
310
311 return 0;
312 default:
313 return -ENOIOCTLCMD;
314 }
315}
316#else
317#define pcf8563_rtc_ioctl NULL
318#endif
319
320static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
321{
322 return pcf8563_get_datetime(to_i2c_client(dev), tm);
323}
324
325static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
326{
327 return pcf8563_set_datetime(to_i2c_client(dev), tm);
328}
329
330static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
331{
332 struct i2c_client *client = to_i2c_client(dev);
333 unsigned char buf[4];
334 int err;
335
336 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
337 if (err)
338 return err;
339
340 dev_dbg(&client->dev,
341 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
342 __func__, buf[0], buf[1], buf[2], buf[3]);
343
344 tm->time.tm_sec = 0;
345 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
346 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
347 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
348 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
349
350 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
351 if (err < 0)
352 return err;
353
354 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
355 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
356 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
357 tm->enabled, tm->pending);
358
359 return 0;
360}
361
362static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
363{
364 struct i2c_client *client = to_i2c_client(dev);
365 unsigned char buf[4];
366 int err;
367
368 /* The alarm has no seconds, round up to nearest minute */
369 if (tm->time.tm_sec) {
370 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
371
372 alarm_time += 60 - tm->time.tm_sec;
373 rtc_time64_to_tm(alarm_time, &tm->time);
374 }
375
376 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
377 "enabled=%d pending=%d\n", __func__,
378 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
379 tm->time.tm_mday, tm->enabled, tm->pending);
380
381 buf[0] = bin2bcd(tm->time.tm_min);
382 buf[1] = bin2bcd(tm->time.tm_hour);
383 buf[2] = bin2bcd(tm->time.tm_mday);
384 buf[3] = tm->time.tm_wday & 0x07;
385
386 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
387 if (err)
388 return err;
389
390 return pcf8563_set_alarm_mode(client, !!tm->enabled);
391}
392
393static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
394{
395 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
396 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
397}
398
399#ifdef CONFIG_COMMON_CLK
400/*
401 * Handling of the clkout
402 */
403
404#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
405
406static int clkout_rates[] = {
407 32768,
408 1024,
409 32,
410 1,
411};
412
413static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
414 unsigned long parent_rate)
415{
416 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
417 struct i2c_client *client = pcf8563->client;
418 unsigned char buf;
419 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
420
421 if (ret < 0)
422 return 0;
423
424 buf &= PCF8563_REG_CLKO_F_MASK;
425 return clkout_rates[buf];
426}
427
428static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
429 unsigned long *prate)
430{
431 int i;
432
433 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
434 if (clkout_rates[i] <= rate)
435 return clkout_rates[i];
436
437 return 0;
438}
439
440static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
441 unsigned long parent_rate)
442{
443 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
444 struct i2c_client *client = pcf8563->client;
445 unsigned char buf;
446 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
447 int i;
448
449 if (ret < 0)
450 return ret;
451
452 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
453 if (clkout_rates[i] == rate) {
454 buf &= ~PCF8563_REG_CLKO_F_MASK;
455 buf |= i;
456 ret = pcf8563_write_block_data(client,
457 PCF8563_REG_CLKO, 1,
458 &buf);
459 return ret;
460 }
461
462 return -EINVAL;
463}
464
465static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
466{
467 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
468 struct i2c_client *client = pcf8563->client;
469 unsigned char buf;
470 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
471
472 if (ret < 0)
473 return ret;
474
475 if (enable)
476 buf |= PCF8563_REG_CLKO_FE;
477 else
478 buf &= ~PCF8563_REG_CLKO_FE;
479
480 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
481 return ret;
482}
483
484static int pcf8563_clkout_prepare(struct clk_hw *hw)
485{
486 return pcf8563_clkout_control(hw, 1);
487}
488
489static void pcf8563_clkout_unprepare(struct clk_hw *hw)
490{
491 pcf8563_clkout_control(hw, 0);
492}
493
494static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
495{
496 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
497 struct i2c_client *client = pcf8563->client;
498 unsigned char buf;
499 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
500
501 if (ret < 0)
502 return ret;
503
504 return !!(buf & PCF8563_REG_CLKO_FE);
505}
506
507static const struct clk_ops pcf8563_clkout_ops = {
508 .prepare = pcf8563_clkout_prepare,
509 .unprepare = pcf8563_clkout_unprepare,
510 .is_prepared = pcf8563_clkout_is_prepared,
511 .recalc_rate = pcf8563_clkout_recalc_rate,
512 .round_rate = pcf8563_clkout_round_rate,
513 .set_rate = pcf8563_clkout_set_rate,
514};
515
516static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
517{
518 struct i2c_client *client = pcf8563->client;
519 struct device_node *node = client->dev.of_node;
520 struct clk *clk;
521 struct clk_init_data init;
522 int ret;
523 unsigned char buf;
524
525 /* disable the clkout output */
526 buf = 0;
527 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
528 if (ret < 0)
529 return ERR_PTR(ret);
530
531 init.name = "pcf8563-clkout";
532 init.ops = &pcf8563_clkout_ops;
533 init.flags = 0;
534 init.parent_names = NULL;
535 init.num_parents = 0;
536 pcf8563->clkout_hw.init = &init;
537
538 /* optional override of the clockname */
539 of_property_read_string(node, "clock-output-names", &init.name);
540
541 /* register the clock */
542 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
543
544 if (!IS_ERR(clk))
545 of_clk_add_provider(node, of_clk_src_simple_get, clk);
546
547 return clk;
548}
549#endif
550
551static const struct rtc_class_ops pcf8563_rtc_ops = {
552 .ioctl = pcf8563_rtc_ioctl,
553 .read_time = pcf8563_rtc_read_time,
554 .set_time = pcf8563_rtc_set_time,
555 .read_alarm = pcf8563_rtc_read_alarm,
556 .set_alarm = pcf8563_rtc_set_alarm,
557 .alarm_irq_enable = pcf8563_irq_enable,
558};
559
560static int pcf8563_probe(struct i2c_client *client,
561 const struct i2c_device_id *id)
562{
563 struct pcf8563 *pcf8563;
564 int err;
565 unsigned char buf;
566 unsigned char alm_pending;
567
568 dev_dbg(&client->dev, "%s\n", __func__);
569
570 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
571 return -ENODEV;
572
573 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
574 GFP_KERNEL);
575 if (!pcf8563)
576 return -ENOMEM;
577
578 i2c_set_clientdata(client, pcf8563);
579 pcf8563->client = client;
580 device_set_wakeup_capable(&client->dev, 1);
581
582 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
583 buf = PCF8563_TMRC_1_60;
584 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
585 if (err < 0) {
586 dev_err(&client->dev, "%s: write error\n", __func__);
587 return err;
588 }
589
590 err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
591 if (err) {
592 dev_err(&client->dev, "%s: read error\n", __func__);
593 return err;
594 }
595 if (alm_pending)
596 pcf8563_set_alarm_mode(client, 0);
597
598 pcf8563->rtc = devm_rtc_device_register(&client->dev,
599 pcf8563_driver.driver.name,
600 &pcf8563_rtc_ops, THIS_MODULE);
601
602 if (IS_ERR(pcf8563->rtc))
603 return PTR_ERR(pcf8563->rtc);
604
605 if (client->irq > 0) {
606 err = devm_request_threaded_irq(&client->dev, client->irq,
607 NULL, pcf8563_irq,
608 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
609 pcf8563_driver.driver.name, client);
610 if (err) {
611 dev_err(&client->dev, "unable to request IRQ %d\n",
612 client->irq);
613 return err;
614 }
615
616 }
617
618#ifdef CONFIG_COMMON_CLK
619 /* register clk in common clk framework */
620 pcf8563_clkout_register_clk(pcf8563);
621#endif
622
623 /* the pcf8563 alarm only supports a minute accuracy */
624 pcf8563->rtc->uie_unsupported = 1;
625
626 return 0;
627}
628
629static const struct i2c_device_id pcf8563_id[] = {
630 { "pcf8563", 0 },
631 { "rtc8564", 0 },
632 { }
633};
634MODULE_DEVICE_TABLE(i2c, pcf8563_id);
635
636#ifdef CONFIG_OF
637static const struct of_device_id pcf8563_of_match[] = {
638 { .compatible = "nxp,pcf8563" },
639 {}
640};
641MODULE_DEVICE_TABLE(of, pcf8563_of_match);
642#endif
643
644static struct i2c_driver pcf8563_driver = {
645 .driver = {
646 .name = "rtc-pcf8563",
647 .of_match_table = of_match_ptr(pcf8563_of_match),
648 },
649 .probe = pcf8563_probe,
650 .id_table = pcf8563_id,
651};
652
653module_i2c_driver(pcf8563_driver);
654
655MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
656MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
657MODULE_LICENSE("GPL");
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 (1 << 1)
26#define PCF8563_BIT_AF (1 << 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
60static struct i2c_driver pcf8563_driver;
61
62struct 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 int voltage_low; /* incicates if a low_voltage was detected */
80
81 struct i2c_client *client;
82#ifdef CONFIG_COMMON_CLK
83 struct clk_hw clkout_hw;
84#endif
85};
86
87static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
88 unsigned char length, unsigned char *buf)
89{
90 struct i2c_msg msgs[] = {
91 {/* setup read ptr */
92 .addr = client->addr,
93 .len = 1,
94 .buf = ®,
95 },
96 {
97 .addr = client->addr,
98 .flags = I2C_M_RD,
99 .len = length,
100 .buf = buf
101 },
102 };
103
104 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
105 dev_err(&client->dev, "%s: read error\n", __func__);
106 return -EIO;
107 }
108
109 return 0;
110}
111
112static int pcf8563_write_block_data(struct i2c_client *client,
113 unsigned char reg, unsigned char length,
114 unsigned char *buf)
115{
116 int i, err;
117
118 for (i = 0; i < length; i++) {
119 unsigned char data[2] = { reg + i, buf[i] };
120
121 err = i2c_master_send(client, data, sizeof(data));
122 if (err != sizeof(data)) {
123 dev_err(&client->dev,
124 "%s: err=%d addr=%02x, data=%02x\n",
125 __func__, err, data[0], data[1]);
126 return -EIO;
127 }
128 }
129
130 return 0;
131}
132
133static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
134{
135 unsigned char buf;
136 int err;
137
138 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
139 if (err < 0)
140 return err;
141
142 if (on)
143 buf |= PCF8563_BIT_AIE;
144 else
145 buf &= ~PCF8563_BIT_AIE;
146
147 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
148
149 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
150 if (err < 0) {
151 dev_err(&client->dev, "%s: write error\n", __func__);
152 return -EIO;
153 }
154
155 return 0;
156}
157
158static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
159 unsigned char *pen)
160{
161 unsigned char buf;
162 int err;
163
164 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
165 if (err)
166 return err;
167
168 if (en)
169 *en = !!(buf & PCF8563_BIT_AIE);
170 if (pen)
171 *pen = !!(buf & PCF8563_BIT_AF);
172
173 return 0;
174}
175
176static irqreturn_t pcf8563_irq(int irq, void *dev_id)
177{
178 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
179 int err;
180 char pending;
181
182 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
183 if (err)
184 return IRQ_NONE;
185
186 if (pending) {
187 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
188 pcf8563_set_alarm_mode(pcf8563->client, 1);
189 return IRQ_HANDLED;
190 }
191
192 return IRQ_NONE;
193}
194
195/*
196 * In the routines that deal directly with the pcf8563 hardware, we use
197 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
198 */
199static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
200{
201 struct i2c_client *client = to_i2c_client(dev);
202 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
203 unsigned char buf[9];
204 int err;
205
206 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
207 if (err)
208 return err;
209
210 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
211 pcf8563->voltage_low = 1;
212 dev_err(&client->dev,
213 "low voltage detected, date/time is not reliable.\n");
214 return -EINVAL;
215 }
216
217 dev_dbg(&client->dev,
218 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
219 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
220 __func__,
221 buf[0], buf[1], buf[2], buf[3],
222 buf[4], buf[5], buf[6], buf[7],
223 buf[8]);
224
225
226 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
227 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
228 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
229 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
230 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
231 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
232 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
233 /* detect the polarity heuristically. see note above. */
234 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
235 (tm->tm_year >= 100) : (tm->tm_year < 100);
236
237 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
238 "mday=%d, mon=%d, year=%d, wday=%d\n",
239 __func__,
240 tm->tm_sec, tm->tm_min, tm->tm_hour,
241 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
242
243 return 0;
244}
245
246static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
247{
248 struct i2c_client *client = to_i2c_client(dev);
249 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
250 unsigned char buf[9];
251
252 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
253 "mday=%d, mon=%d, year=%d, wday=%d\n",
254 __func__,
255 tm->tm_sec, tm->tm_min, tm->tm_hour,
256 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
257
258 /* hours, minutes and seconds */
259 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
260 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
261 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
262
263 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
264
265 /* month, 1 - 12 */
266 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
267
268 /* year and century */
269 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
270 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
271 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
272
273 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
274
275 return pcf8563_write_block_data(client, PCF8563_REG_SC,
276 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
277}
278
279#ifdef CONFIG_RTC_INTF_DEV
280static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
281{
282 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
283 struct rtc_time tm;
284
285 switch (cmd) {
286 case RTC_VL_READ:
287 if (pcf8563->voltage_low)
288 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
289
290 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
291 sizeof(int)))
292 return -EFAULT;
293 return 0;
294 case RTC_VL_CLR:
295 /*
296 * Clear the VL bit in the seconds register in case
297 * the time has not been set already (which would
298 * have cleared it). This does not really matter
299 * because of the cached voltage_low value but do it
300 * anyway for consistency.
301 */
302 if (pcf8563_rtc_read_time(dev, &tm))
303 pcf8563_rtc_set_time(dev, &tm);
304
305 /* Clear the cached value. */
306 pcf8563->voltage_low = 0;
307
308 return 0;
309 default:
310 return -ENOIOCTLCMD;
311 }
312}
313#else
314#define pcf8563_rtc_ioctl NULL
315#endif
316
317static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
318{
319 struct i2c_client *client = to_i2c_client(dev);
320 unsigned char buf[4];
321 int err;
322
323 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
324 if (err)
325 return err;
326
327 dev_dbg(&client->dev,
328 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
329 __func__, buf[0], buf[1], buf[2], buf[3]);
330
331 tm->time.tm_sec = 0;
332 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
333 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
334 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
335 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
336
337 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
338 if (err < 0)
339 return err;
340
341 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
342 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
343 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
344 tm->enabled, tm->pending);
345
346 return 0;
347}
348
349static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
350{
351 struct i2c_client *client = to_i2c_client(dev);
352 unsigned char buf[4];
353 int err;
354
355 /* The alarm has no seconds, round up to nearest minute */
356 if (tm->time.tm_sec) {
357 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
358
359 alarm_time += 60 - tm->time.tm_sec;
360 rtc_time64_to_tm(alarm_time, &tm->time);
361 }
362
363 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
364 "enabled=%d pending=%d\n", __func__,
365 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
366 tm->time.tm_mday, tm->enabled, tm->pending);
367
368 buf[0] = bin2bcd(tm->time.tm_min);
369 buf[1] = bin2bcd(tm->time.tm_hour);
370 buf[2] = bin2bcd(tm->time.tm_mday);
371 buf[3] = tm->time.tm_wday & 0x07;
372
373 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
374 if (err)
375 return err;
376
377 return pcf8563_set_alarm_mode(client, !!tm->enabled);
378}
379
380static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
381{
382 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
383 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
384}
385
386#ifdef CONFIG_COMMON_CLK
387/*
388 * Handling of the clkout
389 */
390
391#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
392
393static int clkout_rates[] = {
394 32768,
395 1024,
396 32,
397 1,
398};
399
400static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
401 unsigned long parent_rate)
402{
403 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
404 struct i2c_client *client = pcf8563->client;
405 unsigned char buf;
406 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
407
408 if (ret < 0)
409 return 0;
410
411 buf &= PCF8563_REG_CLKO_F_MASK;
412 return clkout_rates[buf];
413}
414
415static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
416 unsigned long *prate)
417{
418 int i;
419
420 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
421 if (clkout_rates[i] <= rate)
422 return clkout_rates[i];
423
424 return 0;
425}
426
427static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
428 unsigned long parent_rate)
429{
430 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
431 struct i2c_client *client = pcf8563->client;
432 unsigned char buf;
433 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
434 int i;
435
436 if (ret < 0)
437 return ret;
438
439 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
440 if (clkout_rates[i] == rate) {
441 buf &= ~PCF8563_REG_CLKO_F_MASK;
442 buf |= i;
443 ret = pcf8563_write_block_data(client,
444 PCF8563_REG_CLKO, 1,
445 &buf);
446 return ret;
447 }
448
449 return -EINVAL;
450}
451
452static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
453{
454 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
455 struct i2c_client *client = pcf8563->client;
456 unsigned char buf;
457 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
458
459 if (ret < 0)
460 return ret;
461
462 if (enable)
463 buf |= PCF8563_REG_CLKO_FE;
464 else
465 buf &= ~PCF8563_REG_CLKO_FE;
466
467 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
468 return ret;
469}
470
471static int pcf8563_clkout_prepare(struct clk_hw *hw)
472{
473 return pcf8563_clkout_control(hw, 1);
474}
475
476static void pcf8563_clkout_unprepare(struct clk_hw *hw)
477{
478 pcf8563_clkout_control(hw, 0);
479}
480
481static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
482{
483 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
484 struct i2c_client *client = pcf8563->client;
485 unsigned char buf;
486 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
487
488 if (ret < 0)
489 return ret;
490
491 return !!(buf & PCF8563_REG_CLKO_FE);
492}
493
494static const struct clk_ops pcf8563_clkout_ops = {
495 .prepare = pcf8563_clkout_prepare,
496 .unprepare = pcf8563_clkout_unprepare,
497 .is_prepared = pcf8563_clkout_is_prepared,
498 .recalc_rate = pcf8563_clkout_recalc_rate,
499 .round_rate = pcf8563_clkout_round_rate,
500 .set_rate = pcf8563_clkout_set_rate,
501};
502
503static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
504{
505 struct i2c_client *client = pcf8563->client;
506 struct device_node *node = client->dev.of_node;
507 struct clk *clk;
508 struct clk_init_data init;
509 int ret;
510 unsigned char buf;
511
512 /* disable the clkout output */
513 buf = 0;
514 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
515 if (ret < 0)
516 return ERR_PTR(ret);
517
518 init.name = "pcf8563-clkout";
519 init.ops = &pcf8563_clkout_ops;
520 init.flags = 0;
521 init.parent_names = NULL;
522 init.num_parents = 0;
523 pcf8563->clkout_hw.init = &init;
524
525 /* optional override of the clockname */
526 of_property_read_string(node, "clock-output-names", &init.name);
527
528 /* register the clock */
529 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
530
531 if (!IS_ERR(clk))
532 of_clk_add_provider(node, of_clk_src_simple_get, clk);
533
534 return clk;
535}
536#endif
537
538static const struct rtc_class_ops pcf8563_rtc_ops = {
539 .ioctl = pcf8563_rtc_ioctl,
540 .read_time = pcf8563_rtc_read_time,
541 .set_time = pcf8563_rtc_set_time,
542 .read_alarm = pcf8563_rtc_read_alarm,
543 .set_alarm = pcf8563_rtc_set_alarm,
544 .alarm_irq_enable = pcf8563_irq_enable,
545};
546
547static int pcf8563_probe(struct i2c_client *client,
548 const struct i2c_device_id *id)
549{
550 struct pcf8563 *pcf8563;
551 int err;
552 unsigned char buf;
553
554 dev_dbg(&client->dev, "%s\n", __func__);
555
556 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
557 return -ENODEV;
558
559 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
560 GFP_KERNEL);
561 if (!pcf8563)
562 return -ENOMEM;
563
564 i2c_set_clientdata(client, pcf8563);
565 pcf8563->client = client;
566 device_set_wakeup_capable(&client->dev, 1);
567
568 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
569 buf = PCF8563_TMRC_1_60;
570 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
571 if (err < 0) {
572 dev_err(&client->dev, "%s: write error\n", __func__);
573 return err;
574 }
575
576 /* Clear flags and disable interrupts */
577 buf = 0;
578 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
579 if (err < 0) {
580 dev_err(&client->dev, "%s: write error\n", __func__);
581 return err;
582 }
583
584 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
585 if (IS_ERR(pcf8563->rtc))
586 return PTR_ERR(pcf8563->rtc);
587
588 pcf8563->rtc->ops = &pcf8563_rtc_ops;
589 /* the pcf8563 alarm only supports a minute accuracy */
590 pcf8563->rtc->uie_unsupported = 1;
591 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
592 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
593 pcf8563->rtc->set_start_time = true;
594
595 if (client->irq > 0) {
596 err = devm_request_threaded_irq(&client->dev, client->irq,
597 NULL, pcf8563_irq,
598 IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
599 pcf8563_driver.driver.name, client);
600 if (err) {
601 dev_err(&client->dev, "unable to request IRQ %d\n",
602 client->irq);
603 return err;
604 }
605 }
606
607 err = rtc_register_device(pcf8563->rtc);
608 if (err)
609 return err;
610
611#ifdef CONFIG_COMMON_CLK
612 /* register clk in common clk framework */
613 pcf8563_clkout_register_clk(pcf8563);
614#endif
615
616 return 0;
617}
618
619static const struct i2c_device_id pcf8563_id[] = {
620 { "pcf8563", 0 },
621 { "rtc8564", 0 },
622 { }
623};
624MODULE_DEVICE_TABLE(i2c, pcf8563_id);
625
626#ifdef CONFIG_OF
627static const struct of_device_id pcf8563_of_match[] = {
628 { .compatible = "nxp,pcf8563" },
629 { .compatible = "epson,rtc8564" },
630 { .compatible = "microcrystal,rv8564" },
631 {}
632};
633MODULE_DEVICE_TABLE(of, pcf8563_of_match);
634#endif
635
636static struct i2c_driver pcf8563_driver = {
637 .driver = {
638 .name = "rtc-pcf8563",
639 .of_match_table = of_match_ptr(pcf8563_of_match),
640 },
641 .probe = pcf8563_probe,
642 .id_table = pcf8563_id,
643};
644
645module_i2c_driver(pcf8563_driver);
646
647MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
648MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
649MODULE_LICENSE("GPL");