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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/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
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
80 struct i2c_client *client;
81#ifdef CONFIG_COMMON_CLK
82 struct clk_hw clkout_hw;
83#endif
84};
85
86static 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 = ®,
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
111static 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
132static 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
157static 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
175static 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 */
198static 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
244static 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
277static 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
295static 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
327static 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 buf[0] = bin2bcd(tm->time.tm_min);
334 buf[1] = bin2bcd(tm->time.tm_hour);
335 buf[2] = bin2bcd(tm->time.tm_mday);
336 buf[3] = tm->time.tm_wday & 0x07;
337
338 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
339 if (err)
340 return err;
341
342 return pcf8563_set_alarm_mode(client, !!tm->enabled);
343}
344
345static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
346{
347 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
348 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
349}
350
351#ifdef CONFIG_COMMON_CLK
352/*
353 * Handling of the clkout
354 */
355
356#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
357
358static const int clkout_rates[] = {
359 32768,
360 1024,
361 32,
362 1,
363};
364
365static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
366 unsigned long parent_rate)
367{
368 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
369 struct i2c_client *client = pcf8563->client;
370 unsigned char buf;
371 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
372
373 if (ret < 0)
374 return 0;
375
376 buf &= PCF8563_REG_CLKO_F_MASK;
377 return clkout_rates[buf];
378}
379
380static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
381 unsigned long *prate)
382{
383 int i;
384
385 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
386 if (clkout_rates[i] <= rate)
387 return clkout_rates[i];
388
389 return 0;
390}
391
392static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
393 unsigned long parent_rate)
394{
395 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
396 struct i2c_client *client = pcf8563->client;
397 unsigned char buf;
398 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
399 int i;
400
401 if (ret < 0)
402 return ret;
403
404 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
405 if (clkout_rates[i] == rate) {
406 buf &= ~PCF8563_REG_CLKO_F_MASK;
407 buf |= i;
408 ret = pcf8563_write_block_data(client,
409 PCF8563_REG_CLKO, 1,
410 &buf);
411 return ret;
412 }
413
414 return -EINVAL;
415}
416
417static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
418{
419 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
420 struct i2c_client *client = pcf8563->client;
421 unsigned char buf;
422 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
423
424 if (ret < 0)
425 return ret;
426
427 if (enable)
428 buf |= PCF8563_REG_CLKO_FE;
429 else
430 buf &= ~PCF8563_REG_CLKO_FE;
431
432 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
433 return ret;
434}
435
436static int pcf8563_clkout_prepare(struct clk_hw *hw)
437{
438 return pcf8563_clkout_control(hw, 1);
439}
440
441static void pcf8563_clkout_unprepare(struct clk_hw *hw)
442{
443 pcf8563_clkout_control(hw, 0);
444}
445
446static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
447{
448 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
449 struct i2c_client *client = pcf8563->client;
450 unsigned char buf;
451 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
452
453 if (ret < 0)
454 return ret;
455
456 return !!(buf & PCF8563_REG_CLKO_FE);
457}
458
459static const struct clk_ops pcf8563_clkout_ops = {
460 .prepare = pcf8563_clkout_prepare,
461 .unprepare = pcf8563_clkout_unprepare,
462 .is_prepared = pcf8563_clkout_is_prepared,
463 .recalc_rate = pcf8563_clkout_recalc_rate,
464 .round_rate = pcf8563_clkout_round_rate,
465 .set_rate = pcf8563_clkout_set_rate,
466};
467
468static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
469{
470 struct i2c_client *client = pcf8563->client;
471 struct device_node *node = client->dev.of_node;
472 struct clk *clk;
473 struct clk_init_data init;
474 int ret;
475 unsigned char buf;
476
477 /* disable the clkout output */
478 buf = 0;
479 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
480 if (ret < 0)
481 return ERR_PTR(ret);
482
483 init.name = "pcf8563-clkout";
484 init.ops = &pcf8563_clkout_ops;
485 init.flags = 0;
486 init.parent_names = NULL;
487 init.num_parents = 0;
488 pcf8563->clkout_hw.init = &init;
489
490 /* optional override of the clockname */
491 of_property_read_string(node, "clock-output-names", &init.name);
492
493 /* register the clock */
494 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
495
496 if (!IS_ERR(clk))
497 of_clk_add_provider(node, of_clk_src_simple_get, clk);
498
499 return clk;
500}
501#endif
502
503static const struct rtc_class_ops pcf8563_rtc_ops = {
504 .ioctl = pcf8563_rtc_ioctl,
505 .read_time = pcf8563_rtc_read_time,
506 .set_time = pcf8563_rtc_set_time,
507 .read_alarm = pcf8563_rtc_read_alarm,
508 .set_alarm = pcf8563_rtc_set_alarm,
509 .alarm_irq_enable = pcf8563_irq_enable,
510};
511
512static int pcf8563_probe(struct i2c_client *client)
513{
514 struct pcf8563 *pcf8563;
515 int err;
516 unsigned char buf;
517
518 dev_dbg(&client->dev, "%s\n", __func__);
519
520 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
521 return -ENODEV;
522
523 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
524 GFP_KERNEL);
525 if (!pcf8563)
526 return -ENOMEM;
527
528 i2c_set_clientdata(client, pcf8563);
529 pcf8563->client = client;
530 device_set_wakeup_capable(&client->dev, 1);
531
532 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
533 buf = PCF8563_TMRC_1_60;
534 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
535 if (err < 0) {
536 dev_err(&client->dev, "%s: write error\n", __func__);
537 return err;
538 }
539
540 /* Clear flags and disable interrupts */
541 buf = 0;
542 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
543 if (err < 0) {
544 dev_err(&client->dev, "%s: write error\n", __func__);
545 return err;
546 }
547
548 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
549 if (IS_ERR(pcf8563->rtc))
550 return PTR_ERR(pcf8563->rtc);
551
552 pcf8563->rtc->ops = &pcf8563_rtc_ops;
553 /* the pcf8563 alarm only supports a minute accuracy */
554 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);
555 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);
556 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
557 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
558 pcf8563->rtc->set_start_time = true;
559
560 if (client->irq > 0) {
561 unsigned long irqflags = IRQF_TRIGGER_LOW;
562
563 if (dev_fwnode(&client->dev))
564 irqflags = 0;
565
566 err = devm_request_threaded_irq(&client->dev, client->irq,
567 NULL, pcf8563_irq,
568 IRQF_SHARED | IRQF_ONESHOT | irqflags,
569 pcf8563_driver.driver.name, client);
570 if (err) {
571 dev_err(&client->dev, "unable to request IRQ %d\n",
572 client->irq);
573 return err;
574 }
575 } else {
576 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
577 }
578
579 err = devm_rtc_register_device(pcf8563->rtc);
580 if (err)
581 return err;
582
583#ifdef CONFIG_COMMON_CLK
584 /* register clk in common clk framework */
585 pcf8563_clkout_register_clk(pcf8563);
586#endif
587
588 return 0;
589}
590
591static const struct i2c_device_id pcf8563_id[] = {
592 { "pcf8563", 0 },
593 { "rtc8564", 0 },
594 { "pca8565", 0 },
595 { }
596};
597MODULE_DEVICE_TABLE(i2c, pcf8563_id);
598
599#ifdef CONFIG_OF
600static const struct of_device_id pcf8563_of_match[] = {
601 { .compatible = "nxp,pcf8563" },
602 { .compatible = "epson,rtc8564" },
603 { .compatible = "microcrystal,rv8564" },
604 { .compatible = "nxp,pca8565" },
605 {}
606};
607MODULE_DEVICE_TABLE(of, pcf8563_of_match);
608#endif
609
610static struct i2c_driver pcf8563_driver = {
611 .driver = {
612 .name = "rtc-pcf8563",
613 .of_match_table = of_match_ptr(pcf8563_of_match),
614 },
615 .probe = pcf8563_probe,
616 .id_table = pcf8563_id,
617};
618
619module_i2c_driver(pcf8563_driver);
620
621MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
622MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
623MODULE_LICENSE("GPL");
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/i2c.h>
18#include <linux/bcd.h>
19#include <linux/rtc.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22
23#define DRV_VERSION "0.4.3"
24
25#define PCF8563_REG_ST1 0x00 /* status */
26#define PCF8563_REG_ST2 0x01
27
28#define PCF8563_REG_SC 0x02 /* datetime */
29#define PCF8563_REG_MN 0x03
30#define PCF8563_REG_HR 0x04
31#define PCF8563_REG_DM 0x05
32#define PCF8563_REG_DW 0x06
33#define PCF8563_REG_MO 0x07
34#define PCF8563_REG_YR 0x08
35
36#define PCF8563_REG_AMN 0x09 /* alarm */
37#define PCF8563_REG_AHR 0x0A
38#define PCF8563_REG_ADM 0x0B
39#define PCF8563_REG_ADW 0x0C
40
41#define PCF8563_REG_CLKO 0x0D /* clock out */
42#define PCF8563_REG_TMRC 0x0E /* timer control */
43#define PCF8563_REG_TMR 0x0F /* timer */
44
45#define PCF8563_SC_LV 0x80 /* low voltage */
46#define PCF8563_MO_C 0x80 /* century */
47
48static struct i2c_driver pcf8563_driver;
49
50struct pcf8563 {
51 struct rtc_device *rtc;
52 /*
53 * The meaning of MO_C bit varies by the chip type.
54 * From PCF8563 datasheet: this bit is toggled when the years
55 * register overflows from 99 to 00
56 * 0 indicates the century is 20xx
57 * 1 indicates the century is 19xx
58 * From RTC8564 datasheet: this bit indicates change of
59 * century. When the year digit data overflows from 99 to 00,
60 * this bit is set. By presetting it to 0 while still in the
61 * 20th century, it will be set in year 2000, ...
62 * There seems no reliable way to know how the system use this
63 * bit. So let's do it heuristically, assuming we are live in
64 * 1970...2069.
65 */
66 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
67 int voltage_low; /* incicates if a low_voltage was detected */
68};
69
70/*
71 * In the routines that deal directly with the pcf8563 hardware, we use
72 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
73 */
74static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
75{
76 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
77 unsigned char buf[13] = { PCF8563_REG_ST1 };
78
79 struct i2c_msg msgs[] = {
80 { client->addr, 0, 1, buf }, /* setup read ptr */
81 { client->addr, I2C_M_RD, 13, buf }, /* read status + date */
82 };
83
84 /* read registers */
85 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
86 dev_err(&client->dev, "%s: read error\n", __func__);
87 return -EIO;
88 }
89
90 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
91 pcf8563->voltage_low = 1;
92 dev_info(&client->dev,
93 "low voltage detected, date/time is not reliable.\n");
94 }
95
96 dev_dbg(&client->dev,
97 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
98 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
99 __func__,
100 buf[0], buf[1], buf[2], buf[3],
101 buf[4], buf[5], buf[6], buf[7],
102 buf[8]);
103
104
105 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
106 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
107 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
108 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
109 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
110 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
111 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
112 if (tm->tm_year < 70)
113 tm->tm_year += 100; /* assume we are in 1970...2069 */
114 /* detect the polarity heuristically. see note above. */
115 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
116 (tm->tm_year >= 100) : (tm->tm_year < 100);
117
118 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
119 "mday=%d, mon=%d, year=%d, wday=%d\n",
120 __func__,
121 tm->tm_sec, tm->tm_min, tm->tm_hour,
122 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
123
124 /* the clock can give out invalid datetime, but we cannot return
125 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
126 */
127 if (rtc_valid_tm(tm) < 0)
128 dev_err(&client->dev, "retrieved date/time is not valid.\n");
129
130 return 0;
131}
132
133static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
134{
135 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
136 int i, err;
137 unsigned char buf[9];
138
139 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
140 "mday=%d, mon=%d, year=%d, wday=%d\n",
141 __func__,
142 tm->tm_sec, tm->tm_min, tm->tm_hour,
143 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
144
145 /* hours, minutes and seconds */
146 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
147 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
148 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
149
150 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
151
152 /* month, 1 - 12 */
153 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
154
155 /* year and century */
156 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
157 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
158 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
159
160 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
161
162 /* write register's data */
163 for (i = 0; i < 7; i++) {
164 unsigned char data[2] = { PCF8563_REG_SC + i,
165 buf[PCF8563_REG_SC + i] };
166
167 err = i2c_master_send(client, data, sizeof(data));
168 if (err != sizeof(data)) {
169 dev_err(&client->dev,
170 "%s: err=%d addr=%02x, data=%02x\n",
171 __func__, err, data[0], data[1]);
172 return -EIO;
173 }
174 };
175
176 return 0;
177}
178
179#ifdef CONFIG_RTC_INTF_DEV
180static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
181{
182 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
183 struct rtc_time tm;
184
185 switch (cmd) {
186 case RTC_VL_READ:
187 if (pcf8563->voltage_low)
188 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
189
190 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
191 sizeof(int)))
192 return -EFAULT;
193 return 0;
194 case RTC_VL_CLR:
195 /*
196 * Clear the VL bit in the seconds register in case
197 * the time has not been set already (which would
198 * have cleared it). This does not really matter
199 * because of the cached voltage_low value but do it
200 * anyway for consistency.
201 */
202 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
203 pcf8563_set_datetime(to_i2c_client(dev), &tm);
204
205 /* Clear the cached value. */
206 pcf8563->voltage_low = 0;
207
208 return 0;
209 default:
210 return -ENOIOCTLCMD;
211 }
212}
213#else
214#define pcf8563_rtc_ioctl NULL
215#endif
216
217static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
218{
219 return pcf8563_get_datetime(to_i2c_client(dev), tm);
220}
221
222static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
223{
224 return pcf8563_set_datetime(to_i2c_client(dev), tm);
225}
226
227static const struct rtc_class_ops pcf8563_rtc_ops = {
228 .ioctl = pcf8563_rtc_ioctl,
229 .read_time = pcf8563_rtc_read_time,
230 .set_time = pcf8563_rtc_set_time,
231};
232
233static int pcf8563_probe(struct i2c_client *client,
234 const struct i2c_device_id *id)
235{
236 struct pcf8563 *pcf8563;
237
238 int err = 0;
239
240 dev_dbg(&client->dev, "%s\n", __func__);
241
242 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
243 return -ENODEV;
244
245 pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
246 if (!pcf8563)
247 return -ENOMEM;
248
249 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
250
251 i2c_set_clientdata(client, pcf8563);
252
253 pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
254 &client->dev, &pcf8563_rtc_ops, THIS_MODULE);
255
256 if (IS_ERR(pcf8563->rtc)) {
257 err = PTR_ERR(pcf8563->rtc);
258 goto exit_kfree;
259 }
260
261 return 0;
262
263exit_kfree:
264 kfree(pcf8563);
265
266 return err;
267}
268
269static int pcf8563_remove(struct i2c_client *client)
270{
271 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
272
273 if (pcf8563->rtc)
274 rtc_device_unregister(pcf8563->rtc);
275
276 kfree(pcf8563);
277
278 return 0;
279}
280
281static const struct i2c_device_id pcf8563_id[] = {
282 { "pcf8563", 0 },
283 { "rtc8564", 0 },
284 { }
285};
286MODULE_DEVICE_TABLE(i2c, pcf8563_id);
287
288static struct i2c_driver pcf8563_driver = {
289 .driver = {
290 .name = "rtc-pcf8563",
291 },
292 .probe = pcf8563_probe,
293 .remove = pcf8563_remove,
294 .id_table = pcf8563_id,
295};
296
297module_i2c_driver(pcf8563_driver);
298
299MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
300MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
301MODULE_LICENSE("GPL");
302MODULE_VERSION(DRV_VERSION);