1 // SPDX-License-Identifier: GPL-2.0-only
3 * An I2C driver for the Philips PCF8563 RTC
4 * Copyright 2005-06 Tower Technologies
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 * Maintainers: http://www.nslu2-linux.org/
9 * based on the other drivers in this same directory.
11 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
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>
21 #include <linux/err.h>
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)
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
37 #define PCF8563_REG_AMN 0x09 /* alarm */
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
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
55 #define PCF8563_REG_TMR 0x0F /* timer */
57 #define PCF8563_SC_LV 0x80 /* low voltage */
58 #define PCF8563_MO_C 0x80 /* century */
60 static struct i2c_driver pcf8563_driver;
63 struct rtc_device *rtc;
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
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 */
81 struct i2c_client *client;
82 #ifdef CONFIG_COMMON_CLK
83 struct clk_hw clkout_hw;
87 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
88 unsigned char length, unsigned char *buf)
90 struct i2c_msg msgs[] = {
104 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
105 dev_err(&client->dev, "%s: read error\n", __func__);
112 static int pcf8563_write_block_data(struct i2c_client *client,
113 unsigned char reg, unsigned char length,
118 for (i = 0; i < length; i++) {
119 unsigned char data[2] = { reg + i, buf[i] };
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]);
133 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
138 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
143 buf |= PCF8563_BIT_AIE;
145 buf &= ~PCF8563_BIT_AIE;
147 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
149 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
151 dev_err(&client->dev, "%s: write error\n", __func__);
158 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
164 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
169 *en = !!(buf & PCF8563_BIT_AIE);
171 *pen = !!(buf & PCF8563_BIT_AF);
176 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
178 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
182 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
187 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
188 pcf8563_set_alarm_mode(pcf8563->client, 1);
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.
199 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
201 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
202 unsigned char buf[9];
205 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
209 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
210 pcf8563->voltage_low = 1;
211 dev_err(&client->dev,
212 "low voltage detected, date/time is not reliable.\n");
216 dev_dbg(&client->dev,
217 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
218 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
220 buf[0], buf[1], buf[2], buf[3],
221 buf[4], buf[5], buf[6], buf[7],
225 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
226 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
227 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
228 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
229 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
230 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
231 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
232 if (tm->tm_year < 70)
233 tm->tm_year += 100; /* assume we are in 1970...2069 */
234 /* detect the polarity heuristically. see note above. */
235 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
236 (tm->tm_year >= 100) : (tm->tm_year < 100);
238 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
239 "mday=%d, mon=%d, year=%d, wday=%d\n",
241 tm->tm_sec, tm->tm_min, tm->tm_hour,
242 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
247 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
249 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
250 unsigned char buf[9];
252 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
253 "mday=%d, mon=%d, year=%d, wday=%d\n",
255 tm->tm_sec, tm->tm_min, tm->tm_hour,
256 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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);
263 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
266 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
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;
273 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
275 return pcf8563_write_block_data(client, PCF8563_REG_SC,
276 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
279 #ifdef CONFIG_RTC_INTF_DEV
280 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
282 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
287 if (pcf8563->voltage_low)
288 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
290 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
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.
302 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
303 pcf8563_set_datetime(to_i2c_client(dev), &tm);
305 /* Clear the cached value. */
306 pcf8563->voltage_low = 0;
314 #define pcf8563_rtc_ioctl NULL
317 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
319 return pcf8563_get_datetime(to_i2c_client(dev), tm);
322 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
324 return pcf8563_set_datetime(to_i2c_client(dev), tm);
327 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
329 struct i2c_client *client = to_i2c_client(dev);
330 unsigned char buf[4];
333 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
337 dev_dbg(&client->dev,
338 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
339 __func__, buf[0], buf[1], buf[2], buf[3]);
342 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
343 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
344 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
345 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
347 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
351 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
352 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
353 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
354 tm->enabled, tm->pending);
359 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
361 struct i2c_client *client = to_i2c_client(dev);
362 unsigned char buf[4];
365 /* The alarm has no seconds, round up to nearest minute */
366 if (tm->time.tm_sec) {
367 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
369 alarm_time += 60 - tm->time.tm_sec;
370 rtc_time64_to_tm(alarm_time, &tm->time);
373 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
374 "enabled=%d pending=%d\n", __func__,
375 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
376 tm->time.tm_mday, tm->enabled, tm->pending);
378 buf[0] = bin2bcd(tm->time.tm_min);
379 buf[1] = bin2bcd(tm->time.tm_hour);
380 buf[2] = bin2bcd(tm->time.tm_mday);
381 buf[3] = tm->time.tm_wday & 0x07;
383 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
387 return pcf8563_set_alarm_mode(client, !!tm->enabled);
390 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
392 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
393 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
396 #ifdef CONFIG_COMMON_CLK
398 * Handling of the clkout
401 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
403 static int clkout_rates[] = {
410 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
411 unsigned long parent_rate)
413 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
414 struct i2c_client *client = pcf8563->client;
416 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
421 buf &= PCF8563_REG_CLKO_F_MASK;
422 return clkout_rates[buf];
425 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
426 unsigned long *prate)
430 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
431 if (clkout_rates[i] <= rate)
432 return clkout_rates[i];
437 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
438 unsigned long parent_rate)
440 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
441 struct i2c_client *client = pcf8563->client;
443 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
449 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
450 if (clkout_rates[i] == rate) {
451 buf &= ~PCF8563_REG_CLKO_F_MASK;
453 ret = pcf8563_write_block_data(client,
462 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
464 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
465 struct i2c_client *client = pcf8563->client;
467 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
473 buf |= PCF8563_REG_CLKO_FE;
475 buf &= ~PCF8563_REG_CLKO_FE;
477 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
481 static int pcf8563_clkout_prepare(struct clk_hw *hw)
483 return pcf8563_clkout_control(hw, 1);
486 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
488 pcf8563_clkout_control(hw, 0);
491 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
493 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
494 struct i2c_client *client = pcf8563->client;
496 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
501 return !!(buf & PCF8563_REG_CLKO_FE);
504 static const struct clk_ops pcf8563_clkout_ops = {
505 .prepare = pcf8563_clkout_prepare,
506 .unprepare = pcf8563_clkout_unprepare,
507 .is_prepared = pcf8563_clkout_is_prepared,
508 .recalc_rate = pcf8563_clkout_recalc_rate,
509 .round_rate = pcf8563_clkout_round_rate,
510 .set_rate = pcf8563_clkout_set_rate,
513 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
515 struct i2c_client *client = pcf8563->client;
516 struct device_node *node = client->dev.of_node;
518 struct clk_init_data init;
522 /* disable the clkout output */
524 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
528 init.name = "pcf8563-clkout";
529 init.ops = &pcf8563_clkout_ops;
531 init.parent_names = NULL;
532 init.num_parents = 0;
533 pcf8563->clkout_hw.init = &init;
535 /* optional override of the clockname */
536 of_property_read_string(node, "clock-output-names", &init.name);
538 /* register the clock */
539 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
542 of_clk_add_provider(node, of_clk_src_simple_get, clk);
548 static const struct rtc_class_ops pcf8563_rtc_ops = {
549 .ioctl = pcf8563_rtc_ioctl,
550 .read_time = pcf8563_rtc_read_time,
551 .set_time = pcf8563_rtc_set_time,
552 .read_alarm = pcf8563_rtc_read_alarm,
553 .set_alarm = pcf8563_rtc_set_alarm,
554 .alarm_irq_enable = pcf8563_irq_enable,
557 static int pcf8563_probe(struct i2c_client *client,
558 const struct i2c_device_id *id)
560 struct pcf8563 *pcf8563;
564 dev_dbg(&client->dev, "%s\n", __func__);
566 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
569 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
574 i2c_set_clientdata(client, pcf8563);
575 pcf8563->client = client;
576 device_set_wakeup_capable(&client->dev, 1);
578 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
579 buf = PCF8563_TMRC_1_60;
580 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
582 dev_err(&client->dev, "%s: write error\n", __func__);
586 /* Clear flags and disable interrupts */
588 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
590 dev_err(&client->dev, "%s: write error\n", __func__);
594 pcf8563->rtc = devm_rtc_device_register(&client->dev,
595 pcf8563_driver.driver.name,
596 &pcf8563_rtc_ops, THIS_MODULE);
598 if (IS_ERR(pcf8563->rtc))
599 return PTR_ERR(pcf8563->rtc);
601 if (client->irq > 0) {
602 err = devm_request_threaded_irq(&client->dev, client->irq,
604 IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
605 pcf8563_driver.driver.name, client);
607 dev_err(&client->dev, "unable to request IRQ %d\n",
614 #ifdef CONFIG_COMMON_CLK
615 /* register clk in common clk framework */
616 pcf8563_clkout_register_clk(pcf8563);
619 /* the pcf8563 alarm only supports a minute accuracy */
620 pcf8563->rtc->uie_unsupported = 1;
625 static const struct i2c_device_id pcf8563_id[] = {
630 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
633 static const struct of_device_id pcf8563_of_match[] = {
634 { .compatible = "nxp,pcf8563" },
637 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
640 static struct i2c_driver pcf8563_driver = {
642 .name = "rtc-pcf8563",
643 .of_match_table = of_match_ptr(pcf8563_of_match),
645 .probe = pcf8563_probe,
646 .id_table = pcf8563_id,
649 module_i2c_driver(pcf8563_driver);
651 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
652 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
653 MODULE_LICENSE("GPL");