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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 DRV_VERSION "0.4.4"
27
28#define PCF8563_REG_ST1 0x00 /* status */
29#define PCF8563_REG_ST2 0x01
30#define PCF8563_BIT_AIE (1 << 1)
31#define PCF8563_BIT_AF (1 << 3)
32#define PCF8563_BITS_ST2_N (7 << 5)
33
34#define PCF8563_REG_SC 0x02 /* datetime */
35#define PCF8563_REG_MN 0x03
36#define PCF8563_REG_HR 0x04
37#define PCF8563_REG_DM 0x05
38#define PCF8563_REG_DW 0x06
39#define PCF8563_REG_MO 0x07
40#define PCF8563_REG_YR 0x08
41
42#define PCF8563_REG_AMN 0x09 /* alarm */
43
44#define PCF8563_REG_CLKO 0x0D /* clock out */
45#define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
46#define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
47#define PCF8563_REG_CLKO_F_32768HZ 0x00
48#define PCF8563_REG_CLKO_F_1024HZ 0x01
49#define PCF8563_REG_CLKO_F_32HZ 0x02
50#define PCF8563_REG_CLKO_F_1HZ 0x03
51
52#define PCF8563_REG_TMRC 0x0E /* timer control */
53#define PCF8563_TMRC_ENABLE BIT(7)
54#define PCF8563_TMRC_4096 0
55#define PCF8563_TMRC_64 1
56#define PCF8563_TMRC_1 2
57#define PCF8563_TMRC_1_60 3
58#define PCF8563_TMRC_MASK 3
59
60#define PCF8563_REG_TMR 0x0F /* timer */
61
62#define PCF8563_SC_LV 0x80 /* low voltage */
63#define PCF8563_MO_C 0x80 /* century */
64
65static struct i2c_driver pcf8563_driver;
66
67struct pcf8563 {
68 struct rtc_device *rtc;
69 /*
70 * The meaning of MO_C bit varies by the chip type.
71 * From PCF8563 datasheet: this bit is toggled when the years
72 * register overflows from 99 to 00
73 * 0 indicates the century is 20xx
74 * 1 indicates the century is 19xx
75 * From RTC8564 datasheet: this bit indicates change of
76 * century. When the year digit data overflows from 99 to 00,
77 * this bit is set. By presetting it to 0 while still in the
78 * 20th century, it will be set in year 2000, ...
79 * There seems no reliable way to know how the system use this
80 * bit. So let's do it heuristically, assuming we are live in
81 * 1970...2069.
82 */
83 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
84 int voltage_low; /* incicates if a low_voltage was detected */
85
86 struct i2c_client *client;
87#ifdef CONFIG_COMMON_CLK
88 struct clk_hw clkout_hw;
89#endif
90};
91
92static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
93 unsigned char length, unsigned char *buf)
94{
95 struct i2c_msg msgs[] = {
96 {/* setup read ptr */
97 .addr = client->addr,
98 .len = 1,
99 .buf = ®,
100 },
101 {
102 .addr = client->addr,
103 .flags = I2C_M_RD,
104 .len = length,
105 .buf = buf
106 },
107 };
108
109 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
110 dev_err(&client->dev, "%s: read error\n", __func__);
111 return -EIO;
112 }
113
114 return 0;
115}
116
117static int pcf8563_write_block_data(struct i2c_client *client,
118 unsigned char reg, unsigned char length,
119 unsigned char *buf)
120{
121 int i, err;
122
123 for (i = 0; i < length; i++) {
124 unsigned char data[2] = { reg + i, buf[i] };
125
126 err = i2c_master_send(client, data, sizeof(data));
127 if (err != sizeof(data)) {
128 dev_err(&client->dev,
129 "%s: err=%d addr=%02x, data=%02x\n",
130 __func__, err, data[0], data[1]);
131 return -EIO;
132 }
133 }
134
135 return 0;
136}
137
138static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
139{
140 unsigned char buf;
141 int err;
142
143 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
144 if (err < 0)
145 return err;
146
147 if (on)
148 buf |= PCF8563_BIT_AIE;
149 else
150 buf &= ~PCF8563_BIT_AIE;
151
152 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
153
154 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
155 if (err < 0) {
156 dev_err(&client->dev, "%s: write error\n", __func__);
157 return -EIO;
158 }
159
160 return 0;
161}
162
163static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
164 unsigned char *pen)
165{
166 unsigned char buf;
167 int err;
168
169 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
170 if (err)
171 return err;
172
173 if (en)
174 *en = !!(buf & PCF8563_BIT_AIE);
175 if (pen)
176 *pen = !!(buf & PCF8563_BIT_AF);
177
178 return 0;
179}
180
181static irqreturn_t pcf8563_irq(int irq, void *dev_id)
182{
183 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
184 int err;
185 char pending;
186
187 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
188 if (err)
189 return IRQ_NONE;
190
191 if (pending) {
192 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
193 pcf8563_set_alarm_mode(pcf8563->client, 1);
194 return IRQ_HANDLED;
195 }
196
197 return IRQ_NONE;
198}
199
200/*
201 * In the routines that deal directly with the pcf8563 hardware, we use
202 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
203 */
204static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
205{
206 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
207 unsigned char buf[9];
208 int err;
209
210 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
211 if (err)
212 return err;
213
214 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
215 pcf8563->voltage_low = 1;
216 dev_err(&client->dev,
217 "low voltage detected, date/time is not reliable.\n");
218 return -EINVAL;
219 }
220
221 dev_dbg(&client->dev,
222 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
223 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
224 __func__,
225 buf[0], buf[1], buf[2], buf[3],
226 buf[4], buf[5], buf[6], buf[7],
227 buf[8]);
228
229
230 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
231 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
232 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
233 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
234 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
235 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
236 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
237 if (tm->tm_year < 70)
238 tm->tm_year += 100; /* assume we are in 1970...2069 */
239 /* detect the polarity heuristically. see note above. */
240 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
241 (tm->tm_year >= 100) : (tm->tm_year < 100);
242
243 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
244 "mday=%d, mon=%d, year=%d, wday=%d\n",
245 __func__,
246 tm->tm_sec, tm->tm_min, tm->tm_hour,
247 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
248
249 return 0;
250}
251
252static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
253{
254 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
255 unsigned char buf[9];
256
257 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
258 "mday=%d, mon=%d, year=%d, wday=%d\n",
259 __func__,
260 tm->tm_sec, tm->tm_min, tm->tm_hour,
261 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
262
263 /* hours, minutes and seconds */
264 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
265 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
266 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
267
268 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
269
270 /* month, 1 - 12 */
271 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
272
273 /* year and century */
274 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
275 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
276 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
277
278 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
279
280 return pcf8563_write_block_data(client, PCF8563_REG_SC,
281 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
282}
283
284#ifdef CONFIG_RTC_INTF_DEV
285static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
286{
287 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
288 struct rtc_time tm;
289
290 switch (cmd) {
291 case RTC_VL_READ:
292 if (pcf8563->voltage_low)
293 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
294
295 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
296 sizeof(int)))
297 return -EFAULT;
298 return 0;
299 case RTC_VL_CLR:
300 /*
301 * Clear the VL bit in the seconds register in case
302 * the time has not been set already (which would
303 * have cleared it). This does not really matter
304 * because of the cached voltage_low value but do it
305 * anyway for consistency.
306 */
307 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
308 pcf8563_set_datetime(to_i2c_client(dev), &tm);
309
310 /* Clear the cached value. */
311 pcf8563->voltage_low = 0;
312
313 return 0;
314 default:
315 return -ENOIOCTLCMD;
316 }
317}
318#else
319#define pcf8563_rtc_ioctl NULL
320#endif
321
322static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
323{
324 return pcf8563_get_datetime(to_i2c_client(dev), tm);
325}
326
327static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
328{
329 return pcf8563_set_datetime(to_i2c_client(dev), tm);
330}
331
332static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
333{
334 struct i2c_client *client = to_i2c_client(dev);
335 unsigned char buf[4];
336 int err;
337
338 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
339 if (err)
340 return err;
341
342 dev_dbg(&client->dev,
343 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
344 __func__, buf[0], buf[1], buf[2], buf[3]);
345
346 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
347 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
348 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
349 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
350 tm->time.tm_mon = -1;
351 tm->time.tm_year = -1;
352 tm->time.tm_yday = -1;
353 tm->time.tm_isdst = -1;
354
355 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
356 if (err < 0)
357 return err;
358
359 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
360 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
361 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
362 tm->enabled, tm->pending);
363
364 return 0;
365}
366
367static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
368{
369 struct i2c_client *client = to_i2c_client(dev);
370 unsigned char buf[4];
371 int err;
372
373 /* The alarm has no seconds, round up to nearest minute */
374 if (tm->time.tm_sec) {
375 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
376
377 alarm_time += 60 - tm->time.tm_sec;
378 rtc_time64_to_tm(alarm_time, &tm->time);
379 }
380
381 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
382 "enabled=%d pending=%d\n", __func__,
383 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
384 tm->time.tm_mday, tm->enabled, tm->pending);
385
386 buf[0] = bin2bcd(tm->time.tm_min);
387 buf[1] = bin2bcd(tm->time.tm_hour);
388 buf[2] = bin2bcd(tm->time.tm_mday);
389 buf[3] = tm->time.tm_wday & 0x07;
390
391 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
392 if (err)
393 return err;
394
395 return pcf8563_set_alarm_mode(client, 1);
396}
397
398static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
399{
400 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
401 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
402}
403
404#ifdef CONFIG_COMMON_CLK
405/*
406 * Handling of the clkout
407 */
408
409#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
410
411static int clkout_rates[] = {
412 32768,
413 1024,
414 32,
415 1,
416};
417
418static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
419 unsigned long parent_rate)
420{
421 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
422 struct i2c_client *client = pcf8563->client;
423 unsigned char buf;
424 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
425
426 if (ret < 0)
427 return 0;
428
429 buf &= PCF8563_REG_CLKO_F_MASK;
430 return clkout_rates[ret];
431}
432
433static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
434 unsigned long *prate)
435{
436 int i;
437
438 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
439 if (clkout_rates[i] <= rate)
440 return clkout_rates[i];
441
442 return 0;
443}
444
445static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
446 unsigned long parent_rate)
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 int i;
453
454 if (ret < 0)
455 return ret;
456
457 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
458 if (clkout_rates[i] == rate) {
459 buf &= ~PCF8563_REG_CLKO_F_MASK;
460 buf |= i;
461 ret = pcf8563_write_block_data(client,
462 PCF8563_REG_CLKO, 1,
463 &buf);
464 return ret;
465 }
466
467 return -EINVAL;
468}
469
470static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
471{
472 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
473 struct i2c_client *client = pcf8563->client;
474 unsigned char buf;
475 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
476
477 if (ret < 0)
478 return ret;
479
480 if (enable)
481 buf |= PCF8563_REG_CLKO_FE;
482 else
483 buf &= ~PCF8563_REG_CLKO_FE;
484
485 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
486 return ret;
487}
488
489static int pcf8563_clkout_prepare(struct clk_hw *hw)
490{
491 return pcf8563_clkout_control(hw, 1);
492}
493
494static void pcf8563_clkout_unprepare(struct clk_hw *hw)
495{
496 pcf8563_clkout_control(hw, 0);
497}
498
499static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
500{
501 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
502 struct i2c_client *client = pcf8563->client;
503 unsigned char buf;
504 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
505
506 if (ret < 0)
507 return ret;
508
509 return !!(buf & PCF8563_REG_CLKO_FE);
510}
511
512static const struct clk_ops pcf8563_clkout_ops = {
513 .prepare = pcf8563_clkout_prepare,
514 .unprepare = pcf8563_clkout_unprepare,
515 .is_prepared = pcf8563_clkout_is_prepared,
516 .recalc_rate = pcf8563_clkout_recalc_rate,
517 .round_rate = pcf8563_clkout_round_rate,
518 .set_rate = pcf8563_clkout_set_rate,
519};
520
521static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
522{
523 struct i2c_client *client = pcf8563->client;
524 struct device_node *node = client->dev.of_node;
525 struct clk *clk;
526 struct clk_init_data init;
527 int ret;
528 unsigned char buf;
529
530 /* disable the clkout output */
531 buf = 0;
532 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
533 if (ret < 0)
534 return ERR_PTR(ret);
535
536 init.name = "pcf8563-clkout";
537 init.ops = &pcf8563_clkout_ops;
538 init.flags = CLK_IS_ROOT;
539 init.parent_names = NULL;
540 init.num_parents = 0;
541 pcf8563->clkout_hw.init = &init;
542
543 /* optional override of the clockname */
544 of_property_read_string(node, "clock-output-names", &init.name);
545
546 /* register the clock */
547 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
548
549 if (!IS_ERR(clk))
550 of_clk_add_provider(node, of_clk_src_simple_get, clk);
551
552 return clk;
553}
554#endif
555
556static const struct rtc_class_ops pcf8563_rtc_ops = {
557 .ioctl = pcf8563_rtc_ioctl,
558 .read_time = pcf8563_rtc_read_time,
559 .set_time = pcf8563_rtc_set_time,
560 .read_alarm = pcf8563_rtc_read_alarm,
561 .set_alarm = pcf8563_rtc_set_alarm,
562 .alarm_irq_enable = pcf8563_irq_enable,
563};
564
565static int pcf8563_probe(struct i2c_client *client,
566 const struct i2c_device_id *id)
567{
568 struct pcf8563 *pcf8563;
569 int err;
570 unsigned char buf;
571 unsigned char alm_pending;
572
573 dev_dbg(&client->dev, "%s\n", __func__);
574
575 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
576 return -ENODEV;
577
578 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
579 GFP_KERNEL);
580 if (!pcf8563)
581 return -ENOMEM;
582
583 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
584
585 i2c_set_clientdata(client, pcf8563);
586 pcf8563->client = client;
587 device_set_wakeup_capable(&client->dev, 1);
588
589 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
590 buf = PCF8563_TMRC_1_60;
591 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
592 if (err < 0) {
593 dev_err(&client->dev, "%s: write error\n", __func__);
594 return err;
595 }
596
597 err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
598 if (err) {
599 dev_err(&client->dev, "%s: read error\n", __func__);
600 return err;
601 }
602 if (alm_pending)
603 pcf8563_set_alarm_mode(client, 0);
604
605 pcf8563->rtc = devm_rtc_device_register(&client->dev,
606 pcf8563_driver.driver.name,
607 &pcf8563_rtc_ops, THIS_MODULE);
608
609 if (IS_ERR(pcf8563->rtc))
610 return PTR_ERR(pcf8563->rtc);
611
612 if (client->irq > 0) {
613 err = devm_request_threaded_irq(&client->dev, client->irq,
614 NULL, pcf8563_irq,
615 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
616 pcf8563->rtc->name, client);
617 if (err) {
618 dev_err(&client->dev, "unable to request IRQ %d\n",
619 client->irq);
620 return err;
621 }
622
623 }
624
625#ifdef CONFIG_COMMON_CLK
626 /* register clk in common clk framework */
627 pcf8563_clkout_register_clk(pcf8563);
628#endif
629
630 /* the pcf8563 alarm only supports a minute accuracy */
631 pcf8563->rtc->uie_unsupported = 1;
632
633 return 0;
634}
635
636static const struct i2c_device_id pcf8563_id[] = {
637 { "pcf8563", 0 },
638 { "rtc8564", 0 },
639 { }
640};
641MODULE_DEVICE_TABLE(i2c, pcf8563_id);
642
643#ifdef CONFIG_OF
644static const struct of_device_id pcf8563_of_match[] = {
645 { .compatible = "nxp,pcf8563" },
646 {}
647};
648MODULE_DEVICE_TABLE(of, pcf8563_of_match);
649#endif
650
651static struct i2c_driver pcf8563_driver = {
652 .driver = {
653 .name = "rtc-pcf8563",
654 .of_match_table = of_match_ptr(pcf8563_of_match),
655 },
656 .probe = pcf8563_probe,
657 .id_table = pcf8563_id,
658};
659
660module_i2c_driver(pcf8563_driver);
661
662MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
663MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
664MODULE_LICENSE("GPL");
665MODULE_VERSION(DRV_VERSION);
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);