2 * An I2C driver for the Philips PCF8563 RTC
3 * Copyright 2005-06 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 * Maintainers: http://www.nslu2-linux.org/
8 * based on the other drivers in this same directory.
10 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
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.
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>
23 #include <linux/err.h>
25 #define DRV_VERSION "0.4.3"
27 #define PCF8563_REG_ST1 0x00 /* status */
28 #define PCF8563_REG_ST2 0x01
29 #define PCF8563_BIT_AIE (1 << 1)
30 #define PCF8563_BIT_AF (1 << 3)
32 #define PCF8563_REG_SC 0x02 /* datetime */
33 #define PCF8563_REG_MN 0x03
34 #define PCF8563_REG_HR 0x04
35 #define PCF8563_REG_DM 0x05
36 #define PCF8563_REG_DW 0x06
37 #define PCF8563_REG_MO 0x07
38 #define PCF8563_REG_YR 0x08
40 #define PCF8563_REG_AMN 0x09 /* alarm */
42 #define PCF8563_REG_CLKO 0x0D /* clock out */
43 #define PCF8563_REG_TMRC 0x0E /* timer control */
44 #define PCF8563_REG_TMR 0x0F /* timer */
46 #define PCF8563_SC_LV 0x80 /* low voltage */
47 #define PCF8563_MO_C 0x80 /* century */
49 static struct i2c_driver pcf8563_driver;
52 struct rtc_device *rtc;
54 * The meaning of MO_C bit varies by the chip type.
55 * From PCF8563 datasheet: this bit is toggled when the years
56 * register overflows from 99 to 00
57 * 0 indicates the century is 20xx
58 * 1 indicates the century is 19xx
59 * From RTC8564 datasheet: this bit indicates change of
60 * century. When the year digit data overflows from 99 to 00,
61 * this bit is set. By presetting it to 0 while still in the
62 * 20th century, it will be set in year 2000, ...
63 * There seems no reliable way to know how the system use this
64 * bit. So let's do it heuristically, assuming we are live in
67 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
68 int voltage_low; /* incicates if a low_voltage was detected */
70 struct i2c_client *client;
73 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
74 unsigned char length, unsigned char *buf)
76 struct i2c_msg msgs[] = {
90 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
91 dev_err(&client->dev, "%s: read error\n", __func__);
98 static int pcf8563_write_block_data(struct i2c_client *client,
99 unsigned char reg, unsigned char length,
104 for (i = 0; i < length; i++) {
105 unsigned char data[2] = { reg + i, buf[i] };
107 err = i2c_master_send(client, data, sizeof(data));
108 if (err != sizeof(data)) {
109 dev_err(&client->dev,
110 "%s: err=%d addr=%02x, data=%02x\n",
111 __func__, err, data[0], data[1]);
119 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
124 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
129 buf |= PCF8563_BIT_AIE;
131 buf &= ~PCF8563_BIT_AIE;
133 buf &= ~PCF8563_BIT_AF;
135 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
137 dev_err(&client->dev, "%s: write error\n", __func__);
144 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
150 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
155 *en = !!(buf & PCF8563_BIT_AIE);
157 *pen = !!(buf & PCF8563_BIT_AF);
162 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
164 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
168 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
173 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
174 pcf8563_set_alarm_mode(pcf8563->client, 1);
182 * In the routines that deal directly with the pcf8563 hardware, we use
183 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
185 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
187 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
188 unsigned char buf[9];
191 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
195 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
196 pcf8563->voltage_low = 1;
197 dev_info(&client->dev,
198 "low voltage detected, date/time is not reliable.\n");
201 dev_dbg(&client->dev,
202 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
203 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
205 buf[0], buf[1], buf[2], buf[3],
206 buf[4], buf[5], buf[6], buf[7],
210 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
211 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
212 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
213 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
214 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
215 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
216 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
217 if (tm->tm_year < 70)
218 tm->tm_year += 100; /* assume we are in 1970...2069 */
219 /* detect the polarity heuristically. see note above. */
220 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
221 (tm->tm_year >= 100) : (tm->tm_year < 100);
223 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
224 "mday=%d, mon=%d, year=%d, wday=%d\n",
226 tm->tm_sec, tm->tm_min, tm->tm_hour,
227 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
229 /* the clock can give out invalid datetime, but we cannot return
230 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
232 if (rtc_valid_tm(tm) < 0)
233 dev_err(&client->dev, "retrieved date/time is not valid.\n");
238 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
240 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
242 unsigned char buf[9];
244 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
245 "mday=%d, mon=%d, year=%d, wday=%d\n",
247 tm->tm_sec, tm->tm_min, tm->tm_hour,
248 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
250 /* hours, minutes and seconds */
251 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
252 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
253 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
255 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
258 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
260 /* year and century */
261 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
262 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
263 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
265 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
267 err = pcf8563_write_block_data(client, PCF8563_REG_SC,
268 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
275 #ifdef CONFIG_RTC_INTF_DEV
276 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
278 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
283 if (pcf8563->voltage_low)
284 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
286 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
292 * Clear the VL bit in the seconds register in case
293 * the time has not been set already (which would
294 * have cleared it). This does not really matter
295 * because of the cached voltage_low value but do it
296 * anyway for consistency.
298 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
299 pcf8563_set_datetime(to_i2c_client(dev), &tm);
301 /* Clear the cached value. */
302 pcf8563->voltage_low = 0;
310 #define pcf8563_rtc_ioctl NULL
313 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
315 return pcf8563_get_datetime(to_i2c_client(dev), tm);
318 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
320 return pcf8563_set_datetime(to_i2c_client(dev), tm);
323 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
325 struct i2c_client *client = to_i2c_client(dev);
326 unsigned char buf[4];
329 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
333 dev_dbg(&client->dev,
334 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
335 __func__, buf[0], buf[1], buf[2], buf[3]);
337 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
338 tm->time.tm_hour = bcd2bin(buf[1] & 0x7F);
339 tm->time.tm_mday = bcd2bin(buf[2] & 0x1F);
340 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
341 tm->time.tm_mon = -1;
342 tm->time.tm_year = -1;
343 tm->time.tm_yday = -1;
344 tm->time.tm_isdst = -1;
346 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
350 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
351 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
352 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
353 tm->enabled, tm->pending);
358 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
360 struct i2c_client *client = to_i2c_client(dev);
361 unsigned char buf[4];
364 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
365 "enabled=%d pending=%d\n", __func__,
366 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
367 tm->time.tm_mday, tm->enabled, tm->pending);
369 buf[0] = bin2bcd(tm->time.tm_min);
370 buf[1] = bin2bcd(tm->time.tm_hour);
371 buf[2] = bin2bcd(tm->time.tm_mday);
372 buf[3] = tm->time.tm_wday & 0x07;
374 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
378 return pcf8563_set_alarm_mode(client, 1);
381 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
383 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
386 static const struct rtc_class_ops pcf8563_rtc_ops = {
387 .ioctl = pcf8563_rtc_ioctl,
388 .read_time = pcf8563_rtc_read_time,
389 .set_time = pcf8563_rtc_set_time,
390 .read_alarm = pcf8563_rtc_read_alarm,
391 .set_alarm = pcf8563_rtc_set_alarm,
392 .alarm_irq_enable = pcf8563_irq_enable,
395 static int pcf8563_probe(struct i2c_client *client,
396 const struct i2c_device_id *id)
398 struct pcf8563 *pcf8563;
401 dev_dbg(&client->dev, "%s\n", __func__);
403 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
406 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
411 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
413 i2c_set_clientdata(client, pcf8563);
414 pcf8563->client = client;
415 device_set_wakeup_capable(&client->dev, 1);
417 pcf8563->rtc = devm_rtc_device_register(&client->dev,
418 pcf8563_driver.driver.name,
419 &pcf8563_rtc_ops, THIS_MODULE);
421 if (IS_ERR(pcf8563->rtc))
422 return PTR_ERR(pcf8563->rtc);
424 if (client->irq > 0) {
425 err = devm_request_threaded_irq(&client->dev, client->irq,
427 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
428 pcf8563->rtc->name, client);
430 dev_err(&client->dev, "unable to request IRQ %d\n",
440 static const struct i2c_device_id pcf8563_id[] = {
445 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
448 static const struct of_device_id pcf8563_of_match[] = {
449 { .compatible = "nxp,pcf8563" },
452 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
455 static struct i2c_driver pcf8563_driver = {
457 .name = "rtc-pcf8563",
458 .owner = THIS_MODULE,
459 .of_match_table = of_match_ptr(pcf8563_of_match),
461 .probe = pcf8563_probe,
462 .id_table = pcf8563_id,
465 module_i2c_driver(pcf8563_driver);
467 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
468 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
469 MODULE_LICENSE("GPL");
470 MODULE_VERSION(DRV_VERSION);