Loading...
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(pcf8563->regmap, PCF8563_REG_ST2, &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(pcf8563->regmap, PCF8563_REG_ST2, 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(pcf8563->regmap, PCF8563_REG_ST2, &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, &pending);
131 if (err)
132 return IRQ_NONE;
133
134 if (pending) {
135 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
136 pcf8563_set_alarm_mode(pcf8563, 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(pcf8563->regmap, PCF8563_REG_ST1, buf,
154 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(pcf8563->regmap, PCF8563_REG_SC,
221 buf + PCF8563_REG_SC,
222 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(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(pcf8563->regmap, PCF8563_REG_AMN, buf,
251 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, &tm->enabled, &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(pcf8563->regmap, PCF8563_REG_SC, buf,
289 sizeof(buf));
290 if (err)
291 return err;
292
293 return pcf8563_set_alarm_mode(pcf8563, !!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, !!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(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
326 if (ret < 0)
327 return 0;
328
329 buf &= PCF8563_REG_CLKO_F_MASK;
330 return clkout_rates[buf];
331}
332
333static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
334 unsigned long *prate)
335{
336 int i;
337
338 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
339 if (clkout_rates[i] <= rate)
340 return clkout_rates[i];
341
342 return 0;
343}
344
345static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
346 unsigned long parent_rate)
347{
348 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
349 int i, ret;
350 u32 buf;
351
352 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
353 if (ret < 0)
354 return ret;
355
356 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
357 if (clkout_rates[i] == rate) {
358 buf &= ~PCF8563_REG_CLKO_F_MASK;
359 buf |= i;
360 return regmap_update_bits(pcf8563->regmap,
361 PCF8563_REG_CLKO,
362 PCF8563_REG_CLKO_F_MASK,
363 buf);
364 }
365
366 return -EINVAL;
367}
368
369static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
370{
371 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
372 u32 buf;
373 int ret;
374
375 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
376 if (ret < 0)
377 return ret;
378
379 if (enable)
380 buf |= PCF8563_REG_CLKO_FE;
381 else
382 buf &= ~PCF8563_REG_CLKO_FE;
383
384 return regmap_update_bits(pcf8563->regmap, PCF8563_REG_CLKO,
385 PCF8563_REG_CLKO_FE, buf);
386}
387
388static int pcf8563_clkout_prepare(struct clk_hw *hw)
389{
390 return pcf8563_clkout_control(hw, 1);
391}
392
393static void pcf8563_clkout_unprepare(struct clk_hw *hw)
394{
395 pcf8563_clkout_control(hw, 0);
396}
397
398static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
399{
400 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
401 u32 buf;
402 int ret;
403
404 ret = regmap_read(pcf8563->regmap, PCF8563_REG_CLKO, &buf);
405 if (ret < 0)
406 return ret;
407
408 return !!(buf & PCF8563_REG_CLKO_FE);
409}
410
411static const struct clk_ops pcf8563_clkout_ops = {
412 .prepare = pcf8563_clkout_prepare,
413 .unprepare = pcf8563_clkout_unprepare,
414 .is_prepared = pcf8563_clkout_is_prepared,
415 .recalc_rate = pcf8563_clkout_recalc_rate,
416 .round_rate = pcf8563_clkout_round_rate,
417 .set_rate = pcf8563_clkout_set_rate,
418};
419
420static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
421{
422 struct device_node *node = pcf8563->rtc->dev.of_node;
423 struct clk_init_data init;
424 struct clk *clk;
425 int ret;
426
427 /* disable the clkout output */
428 ret = regmap_clear_bits(pcf8563->regmap, PCF8563_REG_CLKO,
429 PCF8563_REG_CLKO_FE);
430 if (ret < 0)
431 return ERR_PTR(ret);
432
433 init.name = "pcf8563-clkout";
434 init.ops = &pcf8563_clkout_ops;
435 init.flags = 0;
436 init.parent_names = NULL;
437 init.num_parents = 0;
438 pcf8563->clkout_hw.init = &init;
439
440 /* optional override of the clockname */
441 of_property_read_string(node, "clock-output-names", &init.name);
442
443 /* register the clock */
444 clk = devm_clk_register(&pcf8563->rtc->dev, &pcf8563->clkout_hw);
445
446 if (!IS_ERR(clk))
447 of_clk_add_provider(node, of_clk_src_simple_get, clk);
448
449 return clk;
450}
451#endif
452
453static const struct rtc_class_ops pcf8563_rtc_ops = {
454 .ioctl = pcf8563_rtc_ioctl,
455 .read_time = pcf8563_rtc_read_time,
456 .set_time = pcf8563_rtc_set_time,
457 .read_alarm = pcf8563_rtc_read_alarm,
458 .set_alarm = pcf8563_rtc_set_alarm,
459 .alarm_irq_enable = pcf8563_irq_enable,
460};
461
462static const struct regmap_config regmap_config = {
463 .reg_bits = 8,
464 .val_bits = 8,
465 .max_register = 0xF,
466};
467
468static int pcf8563_probe(struct i2c_client *client)
469{
470 struct pcf8563 *pcf8563;
471 int err;
472
473 dev_dbg(&client->dev, "%s\n", __func__);
474
475 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
476 return -ENODEV;
477
478 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
479 GFP_KERNEL);
480 if (!pcf8563)
481 return -ENOMEM;
482
483 pcf8563->regmap = devm_regmap_init_i2c(client, ®map_config);
484 if (IS_ERR(pcf8563->regmap))
485 return PTR_ERR(pcf8563->regmap);
486
487 i2c_set_clientdata(client, pcf8563);
488 device_set_wakeup_capable(&client->dev, 1);
489
490 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
491 err = regmap_set_bits(pcf8563->regmap, PCF8563_REG_TMRC,
492 PCF8563_TMRC_1_60);
493 if (err < 0) {
494 dev_err(&client->dev, "%s: write error\n", __func__);
495 return err;
496 }
497
498 /* Clear flags and disable interrupts */
499 err = regmap_write(pcf8563->regmap, PCF8563_REG_ST2, 0);
500 if (err < 0) {
501 dev_err(&client->dev, "%s: write error\n", __func__);
502 return err;
503 }
504
505 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
506 if (IS_ERR(pcf8563->rtc))
507 return PTR_ERR(pcf8563->rtc);
508
509 pcf8563->rtc->ops = &pcf8563_rtc_ops;
510 /* the pcf8563 alarm only supports a minute accuracy */
511 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);
512 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);
513 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
514 pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
515 pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
516 pcf8563->rtc->set_start_time = true;
517
518 if (client->irq > 0) {
519 unsigned long irqflags = IRQF_TRIGGER_LOW;
520
521 if (dev_fwnode(&client->dev))
522 irqflags = 0;
523
524 err = devm_request_threaded_irq(&client->dev, client->irq,
525 NULL, pcf8563_irq,
526 IRQF_SHARED | IRQF_ONESHOT | irqflags,
527 pcf8563_driver.driver.name, client);
528 if (err) {
529 dev_err(&client->dev, "unable to request IRQ %d\n",
530 client->irq);
531 return err;
532 }
533 } else {
534 client->irq = 0;
535 }
536
537 if (client->irq > 0 || device_property_read_bool(&client->dev, "wakeup-source")) {
538 device_init_wakeup(&client->dev, true);
539 set_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
540 }
541
542 err = devm_rtc_register_device(pcf8563->rtc);
543 if (err)
544 return err;
545
546#ifdef CONFIG_COMMON_CLK
547 /* register clk in common clk framework */
548 pcf8563_clkout_register_clk(pcf8563);
549#endif
550
551 return 0;
552}
553
554static const struct i2c_device_id pcf8563_id[] = {
555 { "pcf8563" },
556 { "rtc8564" },
557 { "pca8565" },
558 { }
559};
560MODULE_DEVICE_TABLE(i2c, pcf8563_id);
561
562#ifdef CONFIG_OF
563static const struct of_device_id pcf8563_of_match[] = {
564 { .compatible = "nxp,pcf8563" },
565 { .compatible = "epson,rtc8564" },
566 { .compatible = "microcrystal,rv8564" },
567 { .compatible = "nxp,pca8565" },
568 {}
569};
570MODULE_DEVICE_TABLE(of, pcf8563_of_match);
571#endif
572
573static struct i2c_driver pcf8563_driver = {
574 .driver = {
575 .name = "rtc-pcf8563",
576 .of_match_table = of_match_ptr(pcf8563_of_match),
577 },
578 .probe = pcf8563_probe,
579 .id_table = pcf8563_id,
580};
581
582module_i2c_driver(pcf8563_driver);
583
584MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
585MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
586MODULE_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#include <linux/of.h>
23#include <linux/err.h>
24
25#define DRV_VERSION "0.4.3"
26
27#define PCF8563_REG_ST1 0x00 /* status */
28#define PCF8563_REG_ST2 0x01
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#define PCF8563_REG_AHR 0x0A
40#define PCF8563_REG_ADM 0x0B
41#define PCF8563_REG_ADW 0x0C
42
43#define PCF8563_REG_CLKO 0x0D /* clock out */
44#define PCF8563_REG_TMRC 0x0E /* timer control */
45#define PCF8563_REG_TMR 0x0F /* timer */
46
47#define PCF8563_SC_LV 0x80 /* low voltage */
48#define PCF8563_MO_C 0x80 /* century */
49
50static struct i2c_driver pcf8563_driver;
51
52struct pcf8563 {
53 struct rtc_device *rtc;
54 /*
55 * The meaning of MO_C bit varies by the chip type.
56 * From PCF8563 datasheet: this bit is toggled when the years
57 * register overflows from 99 to 00
58 * 0 indicates the century is 20xx
59 * 1 indicates the century is 19xx
60 * From RTC8564 datasheet: this bit indicates change of
61 * century. When the year digit data overflows from 99 to 00,
62 * this bit is set. By presetting it to 0 while still in the
63 * 20th century, it will be set in year 2000, ...
64 * There seems no reliable way to know how the system use this
65 * bit. So let's do it heuristically, assuming we are live in
66 * 1970...2069.
67 */
68 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
69 int voltage_low; /* incicates if a low_voltage was detected */
70};
71
72/*
73 * In the routines that deal directly with the pcf8563 hardware, we use
74 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
75 */
76static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
77{
78 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
79 unsigned char buf[13] = { PCF8563_REG_ST1 };
80
81 struct i2c_msg msgs[] = {
82 {/* setup read ptr */
83 .addr = client->addr,
84 .len = 1,
85 .buf = buf
86 },
87 {/* read status + date */
88 .addr = client->addr,
89 .flags = I2C_M_RD,
90 .len = 13,
91 .buf = buf
92 },
93 };
94
95 /* read registers */
96 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
97 dev_err(&client->dev, "%s: read error\n", __func__);
98 return -EIO;
99 }
100
101 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
102 pcf8563->voltage_low = 1;
103 dev_info(&client->dev,
104 "low voltage detected, date/time is not reliable.\n");
105 }
106
107 dev_dbg(&client->dev,
108 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
109 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
110 __func__,
111 buf[0], buf[1], buf[2], buf[3],
112 buf[4], buf[5], buf[6], buf[7],
113 buf[8]);
114
115
116 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
117 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
118 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
119 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
120 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
121 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
122 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
123 if (tm->tm_year < 70)
124 tm->tm_year += 100; /* assume we are in 1970...2069 */
125 /* detect the polarity heuristically. see note above. */
126 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
127 (tm->tm_year >= 100) : (tm->tm_year < 100);
128
129 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
130 "mday=%d, mon=%d, year=%d, wday=%d\n",
131 __func__,
132 tm->tm_sec, tm->tm_min, tm->tm_hour,
133 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
134
135 /* the clock can give out invalid datetime, but we cannot return
136 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
137 */
138 if (rtc_valid_tm(tm) < 0)
139 dev_err(&client->dev, "retrieved date/time is not valid.\n");
140
141 return 0;
142}
143
144static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
145{
146 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
147 int i, err;
148 unsigned char buf[9];
149
150 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
151 "mday=%d, mon=%d, year=%d, wday=%d\n",
152 __func__,
153 tm->tm_sec, tm->tm_min, tm->tm_hour,
154 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
155
156 /* hours, minutes and seconds */
157 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
158 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
159 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
160
161 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
162
163 /* month, 1 - 12 */
164 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
165
166 /* year and century */
167 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
168 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
169 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
170
171 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
172
173 /* write register's data */
174 for (i = 0; i < 7; i++) {
175 unsigned char data[2] = { PCF8563_REG_SC + i,
176 buf[PCF8563_REG_SC + i] };
177
178 err = i2c_master_send(client, data, sizeof(data));
179 if (err != sizeof(data)) {
180 dev_err(&client->dev,
181 "%s: err=%d addr=%02x, data=%02x\n",
182 __func__, err, data[0], data[1]);
183 return -EIO;
184 }
185 }
186
187 return 0;
188}
189
190#ifdef CONFIG_RTC_INTF_DEV
191static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
192{
193 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
194 struct rtc_time tm;
195
196 switch (cmd) {
197 case RTC_VL_READ:
198 if (pcf8563->voltage_low)
199 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
200
201 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
202 sizeof(int)))
203 return -EFAULT;
204 return 0;
205 case RTC_VL_CLR:
206 /*
207 * Clear the VL bit in the seconds register in case
208 * the time has not been set already (which would
209 * have cleared it). This does not really matter
210 * because of the cached voltage_low value but do it
211 * anyway for consistency.
212 */
213 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
214 pcf8563_set_datetime(to_i2c_client(dev), &tm);
215
216 /* Clear the cached value. */
217 pcf8563->voltage_low = 0;
218
219 return 0;
220 default:
221 return -ENOIOCTLCMD;
222 }
223}
224#else
225#define pcf8563_rtc_ioctl NULL
226#endif
227
228static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
229{
230 return pcf8563_get_datetime(to_i2c_client(dev), tm);
231}
232
233static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
234{
235 return pcf8563_set_datetime(to_i2c_client(dev), tm);
236}
237
238static const struct rtc_class_ops pcf8563_rtc_ops = {
239 .ioctl = pcf8563_rtc_ioctl,
240 .read_time = pcf8563_rtc_read_time,
241 .set_time = pcf8563_rtc_set_time,
242};
243
244static int pcf8563_probe(struct i2c_client *client,
245 const struct i2c_device_id *id)
246{
247 struct pcf8563 *pcf8563;
248
249 dev_dbg(&client->dev, "%s\n", __func__);
250
251 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
252 return -ENODEV;
253
254 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
255 GFP_KERNEL);
256 if (!pcf8563)
257 return -ENOMEM;
258
259 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
260
261 i2c_set_clientdata(client, pcf8563);
262
263 pcf8563->rtc = devm_rtc_device_register(&client->dev,
264 pcf8563_driver.driver.name,
265 &pcf8563_rtc_ops, THIS_MODULE);
266
267 return PTR_ERR_OR_ZERO(pcf8563->rtc);
268}
269
270static const struct i2c_device_id pcf8563_id[] = {
271 { "pcf8563", 0 },
272 { "rtc8564", 0 },
273 { }
274};
275MODULE_DEVICE_TABLE(i2c, pcf8563_id);
276
277#ifdef CONFIG_OF
278static const struct of_device_id pcf8563_of_match[] = {
279 { .compatible = "nxp,pcf8563" },
280 {}
281};
282MODULE_DEVICE_TABLE(of, pcf8563_of_match);
283#endif
284
285static struct i2c_driver pcf8563_driver = {
286 .driver = {
287 .name = "rtc-pcf8563",
288 .owner = THIS_MODULE,
289 .of_match_table = of_match_ptr(pcf8563_of_match),
290 },
291 .probe = pcf8563_probe,
292 .id_table = pcf8563_id,
293};
294
295module_i2c_driver(pcf8563_driver);
296
297MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
298MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
299MODULE_LICENSE("GPL");
300MODULE_VERSION(DRV_VERSION);