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 * https://www.nxp.com/docs/en/data-sheet/PCF8563.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 BIT(1)
26 #define PCF8563_BIT_AF BIT(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 */
80 struct i2c_client *client;
81 #ifdef CONFIG_COMMON_CLK
82 struct clk_hw clkout_hw;
86 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
87 unsigned char length, unsigned char *buf)
89 struct i2c_msg msgs[] = {
103 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
104 dev_err(&client->dev, "%s: read error\n", __func__);
111 static int pcf8563_write_block_data(struct i2c_client *client,
112 unsigned char reg, unsigned char length,
117 for (i = 0; i < length; i++) {
118 unsigned char data[2] = { reg + i, buf[i] };
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]);
132 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
137 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
142 buf |= PCF8563_BIT_AIE;
144 buf &= ~PCF8563_BIT_AIE;
146 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
148 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
150 dev_err(&client->dev, "%s: write error\n", __func__);
157 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
163 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
168 *en = !!(buf & PCF8563_BIT_AIE);
170 *pen = !!(buf & PCF8563_BIT_AF);
175 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
177 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
181 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
186 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
187 pcf8563_set_alarm_mode(pcf8563->client, 1);
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.
198 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
200 struct i2c_client *client = to_i2c_client(dev);
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 dev_err(&client->dev,
211 "low voltage detected, date/time is not reliable.\n");
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",
219 buf[0], buf[1], buf[2], buf[3],
220 buf[4], buf[5], buf[6], buf[7],
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);
235 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
236 "mday=%d, mon=%d, year=%d, wday=%d\n",
238 tm->tm_sec, tm->tm_min, tm->tm_hour,
239 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
244 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
246 struct i2c_client *client = to_i2c_client(dev);
247 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
248 unsigned char buf[9];
250 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
251 "mday=%d, mon=%d, year=%d, wday=%d\n",
253 tm->tm_sec, tm->tm_min, tm->tm_hour,
254 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
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);
261 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
264 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
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;
271 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
273 return pcf8563_write_block_data(client, PCF8563_REG_SC,
274 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
277 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
279 struct i2c_client *client = to_i2c_client(dev);
284 ret = i2c_smbus_read_byte_data(client, PCF8563_REG_SC);
288 return put_user(ret & PCF8563_SC_LV ? RTC_VL_DATA_INVALID : 0,
289 (unsigned int __user *)arg);
295 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
297 struct i2c_client *client = to_i2c_client(dev);
298 unsigned char buf[4];
301 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
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]);
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);
315 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
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);
327 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
329 struct i2c_client *client = to_i2c_client(dev);
330 unsigned char buf[4];
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;
338 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
342 return pcf8563_set_alarm_mode(client, !!tm->enabled);
345 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
347 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
348 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
351 #ifdef CONFIG_COMMON_CLK
353 * Handling of the clkout
356 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
358 static const int clkout_rates[] = {
365 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
366 unsigned long parent_rate)
368 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
369 struct i2c_client *client = pcf8563->client;
371 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
376 buf &= PCF8563_REG_CLKO_F_MASK;
377 return clkout_rates[buf];
380 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
381 unsigned long *prate)
385 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
386 if (clkout_rates[i] <= rate)
387 return clkout_rates[i];
392 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
393 unsigned long parent_rate)
395 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
396 struct i2c_client *client = pcf8563->client;
398 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
404 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
405 if (clkout_rates[i] == rate) {
406 buf &= ~PCF8563_REG_CLKO_F_MASK;
408 ret = pcf8563_write_block_data(client,
417 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
419 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
420 struct i2c_client *client = pcf8563->client;
422 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
428 buf |= PCF8563_REG_CLKO_FE;
430 buf &= ~PCF8563_REG_CLKO_FE;
432 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
436 static int pcf8563_clkout_prepare(struct clk_hw *hw)
438 return pcf8563_clkout_control(hw, 1);
441 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
443 pcf8563_clkout_control(hw, 0);
446 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
448 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
449 struct i2c_client *client = pcf8563->client;
451 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
456 return !!(buf & PCF8563_REG_CLKO_FE);
459 static 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,
468 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
470 struct i2c_client *client = pcf8563->client;
471 struct device_node *node = client->dev.of_node;
473 struct clk_init_data init;
477 /* disable the clkout output */
479 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
483 init.name = "pcf8563-clkout";
484 init.ops = &pcf8563_clkout_ops;
486 init.parent_names = NULL;
487 init.num_parents = 0;
488 pcf8563->clkout_hw.init = &init;
490 /* optional override of the clockname */
491 of_property_read_string(node, "clock-output-names", &init.name);
493 /* register the clock */
494 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
497 of_clk_add_provider(node, of_clk_src_simple_get, clk);
503 static 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,
512 static int pcf8563_probe(struct i2c_client *client)
514 struct pcf8563 *pcf8563;
518 dev_dbg(&client->dev, "%s\n", __func__);
520 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
523 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
528 i2c_set_clientdata(client, pcf8563);
529 pcf8563->client = client;
530 device_set_wakeup_capable(&client->dev, 1);
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);
536 dev_err(&client->dev, "%s: write error\n", __func__);
540 /* Clear flags and disable interrupts */
542 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
544 dev_err(&client->dev, "%s: write error\n", __func__);
548 pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
549 if (IS_ERR(pcf8563->rtc))
550 return PTR_ERR(pcf8563->rtc);
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;
560 if (client->irq > 0) {
561 unsigned long irqflags = IRQF_TRIGGER_LOW;
563 if (dev_fwnode(&client->dev))
566 err = devm_request_threaded_irq(&client->dev, client->irq,
568 IRQF_SHARED | IRQF_ONESHOT | irqflags,
569 pcf8563_driver.driver.name, client);
571 dev_err(&client->dev, "unable to request IRQ %d\n",
576 clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
579 err = devm_rtc_register_device(pcf8563->rtc);
583 #ifdef CONFIG_COMMON_CLK
584 /* register clk in common clk framework */
585 pcf8563_clkout_register_clk(pcf8563);
591 static const struct i2c_device_id pcf8563_id[] = {
597 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
600 static const struct of_device_id pcf8563_of_match[] = {
601 { .compatible = "nxp,pcf8563" },
602 { .compatible = "epson,rtc8564" },
603 { .compatible = "microcrystal,rv8564" },
604 { .compatible = "nxp,pca8565" },
607 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
610 static struct i2c_driver pcf8563_driver = {
612 .name = "rtc-pcf8563",
613 .of_match_table = of_match_ptr(pcf8563_of_match),
615 .probe = pcf8563_probe,
616 .id_table = pcf8563_id,
619 module_i2c_driver(pcf8563_driver);
621 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
622 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
623 MODULE_LICENSE("GPL");