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 #define PCF8563_BIT_AIE (1 << 1)
30 #define PCF8563_BIT_AF (1 << 3)
31
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
39
40 #define PCF8563_REG_AMN 0x09 /* alarm */
41
42 #define PCF8563_REG_CLKO 0x0D /* clock out */
43 #define PCF8563_REG_TMRC 0x0E /* timer control */
44 #define PCF8563_REG_TMR 0x0F /* timer */
45
46 #define PCF8563_SC_LV 0x80 /* low voltage */
47 #define PCF8563_MO_C 0x80 /* century */
48
49 static struct i2c_driver pcf8563_driver;
50
51 struct pcf8563 {
52 struct rtc_device *rtc;
53 /*
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
65 * 1970...2069.
66 */
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 */
69
70 struct i2c_client *client;
71 };
72
pcf8563_read_block_data(struct i2c_client * client,unsigned char reg,unsigned char length,unsigned char * buf)73 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
74 unsigned char length, unsigned char *buf)
75 {
76 struct i2c_msg msgs[] = {
77 {/* setup read ptr */
78 .addr = client->addr,
79 .len = 1,
80 .buf = ®,
81 },
82 {
83 .addr = client->addr,
84 .flags = I2C_M_RD,
85 .len = length,
86 .buf = buf
87 },
88 };
89
90 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
91 dev_err(&client->dev, "%s: read error\n", __func__);
92 return -EIO;
93 }
94
95 return 0;
96 }
97
pcf8563_write_block_data(struct i2c_client * client,unsigned char reg,unsigned char length,unsigned char * buf)98 static int pcf8563_write_block_data(struct i2c_client *client,
99 unsigned char reg, unsigned char length,
100 unsigned char *buf)
101 {
102 int i, err;
103
104 for (i = 0; i < length; i++) {
105 unsigned char data[2] = { reg + i, buf[i] };
106
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]);
112 return -EIO;
113 }
114 }
115
116 return 0;
117 }
118
pcf8563_set_alarm_mode(struct i2c_client * client,bool on)119 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
120 {
121 unsigned char buf[2];
122 int err;
123
124 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, buf + 1);
125 if (err < 0)
126 return err;
127
128 if (on)
129 buf[1] |= PCF8563_BIT_AIE;
130 else
131 buf[1] &= ~PCF8563_BIT_AIE;
132
133 buf[1] &= ~PCF8563_BIT_AF;
134 buf[0] = PCF8563_REG_ST2;
135
136 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, buf + 1);
137 if (err < 0) {
138 dev_err(&client->dev, "%s: write error\n", __func__);
139 return -EIO;
140 }
141
142 return 0;
143 }
144
pcf8563_get_alarm_mode(struct i2c_client * client,unsigned char * en,unsigned char * pen)145 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
146 unsigned char *pen)
147 {
148 unsigned char buf;
149 int err;
150
151 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
152 if (err)
153 return err;
154
155 if (en)
156 *en = !!(buf & PCF8563_BIT_AIE);
157 if (pen)
158 *pen = !!(buf & PCF8563_BIT_AF);
159
160 return 0;
161 }
162
pcf8563_irq(int irq,void * dev_id)163 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
164 {
165 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
166 int err;
167 char pending;
168
169 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
170 if (err)
171 return IRQ_NONE;
172
173 if (pending) {
174 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
175 pcf8563_set_alarm_mode(pcf8563->client, 1);
176 return IRQ_HANDLED;
177 }
178
179 return IRQ_NONE;
180 }
181
182 /*
183 * In the routines that deal directly with the pcf8563 hardware, we use
184 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
185 */
pcf8563_get_datetime(struct i2c_client * client,struct rtc_time * tm)186 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
187 {
188 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
189 unsigned char buf[9];
190 int err;
191
192 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
193 if (err)
194 return err;
195
196 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
197 pcf8563->voltage_low = 1;
198 dev_info(&client->dev,
199 "low voltage detected, date/time is not reliable.\n");
200 }
201
202 dev_dbg(&client->dev,
203 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
204 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
205 __func__,
206 buf[0], buf[1], buf[2], buf[3],
207 buf[4], buf[5], buf[6], buf[7],
208 buf[8]);
209
210
211 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
212 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
213 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
214 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
215 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
216 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
217 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
218 if (tm->tm_year < 70)
219 tm->tm_year += 100; /* assume we are in 1970...2069 */
220 /* detect the polarity heuristically. see note above. */
221 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
222 (tm->tm_year >= 100) : (tm->tm_year < 100);
223
224 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
225 "mday=%d, mon=%d, year=%d, wday=%d\n",
226 __func__,
227 tm->tm_sec, tm->tm_min, tm->tm_hour,
228 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
229
230 /* the clock can give out invalid datetime, but we cannot return
231 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
232 */
233 if (rtc_valid_tm(tm) < 0)
234 dev_err(&client->dev, "retrieved date/time is not valid.\n");
235
236 return 0;
237 }
238
pcf8563_set_datetime(struct i2c_client * client,struct rtc_time * tm)239 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
240 {
241 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
242 int err;
243 unsigned char buf[9];
244
245 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
246 "mday=%d, mon=%d, year=%d, wday=%d\n",
247 __func__,
248 tm->tm_sec, tm->tm_min, tm->tm_hour,
249 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
250
251 /* hours, minutes and seconds */
252 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
253 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
254 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
255
256 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
257
258 /* month, 1 - 12 */
259 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
260
261 /* year and century */
262 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
263 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
264 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
265
266 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
267
268 err = pcf8563_write_block_data(client, PCF8563_REG_SC,
269 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
270 if (err)
271 return err;
272
273 return 0;
274 }
275
276 #ifdef CONFIG_RTC_INTF_DEV
pcf8563_rtc_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)277 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
278 {
279 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
280 struct rtc_time tm;
281
282 switch (cmd) {
283 case RTC_VL_READ:
284 if (pcf8563->voltage_low)
285 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
286
287 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
288 sizeof(int)))
289 return -EFAULT;
290 return 0;
291 case RTC_VL_CLR:
292 /*
293 * Clear the VL bit in the seconds register in case
294 * the time has not been set already (which would
295 * have cleared it). This does not really matter
296 * because of the cached voltage_low value but do it
297 * anyway for consistency.
298 */
299 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
300 pcf8563_set_datetime(to_i2c_client(dev), &tm);
301
302 /* Clear the cached value. */
303 pcf8563->voltage_low = 0;
304
305 return 0;
306 default:
307 return -ENOIOCTLCMD;
308 }
309 }
310 #else
311 #define pcf8563_rtc_ioctl NULL
312 #endif
313
pcf8563_rtc_read_time(struct device * dev,struct rtc_time * tm)314 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
315 {
316 return pcf8563_get_datetime(to_i2c_client(dev), tm);
317 }
318
pcf8563_rtc_set_time(struct device * dev,struct rtc_time * tm)319 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
320 {
321 return pcf8563_set_datetime(to_i2c_client(dev), tm);
322 }
323
pcf8563_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * tm)324 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
325 {
326 struct i2c_client *client = to_i2c_client(dev);
327 unsigned char buf[4];
328 int err;
329
330 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
331 if (err)
332 return err;
333
334 dev_dbg(&client->dev,
335 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
336 __func__, buf[0], buf[1], buf[2], buf[3]);
337
338 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
339 tm->time.tm_hour = bcd2bin(buf[1] & 0x7F);
340 tm->time.tm_mday = bcd2bin(buf[2] & 0x1F);
341 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
342 tm->time.tm_mon = -1;
343 tm->time.tm_year = -1;
344 tm->time.tm_yday = -1;
345 tm->time.tm_isdst = -1;
346
347 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
348 if (err < 0)
349 return err;
350
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);
355
356 return 0;
357 }
358
pcf8563_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * tm)359 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
360 {
361 struct i2c_client *client = to_i2c_client(dev);
362 unsigned char buf[4];
363 int err;
364
365 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
366 "enabled=%d pending=%d\n", __func__,
367 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
368 tm->time.tm_mday, tm->enabled, tm->pending);
369
370 buf[0] = bin2bcd(tm->time.tm_min);
371 buf[1] = bin2bcd(tm->time.tm_hour);
372 buf[2] = bin2bcd(tm->time.tm_mday);
373 buf[3] = tm->time.tm_wday & 0x07;
374
375 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
376 if (err)
377 return err;
378
379 return pcf8563_set_alarm_mode(client, 1);
380 }
381
pcf8563_irq_enable(struct device * dev,unsigned int enabled)382 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
383 {
384 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
385 }
386
387 static const struct rtc_class_ops pcf8563_rtc_ops = {
388 .ioctl = pcf8563_rtc_ioctl,
389 .read_time = pcf8563_rtc_read_time,
390 .set_time = pcf8563_rtc_set_time,
391 .read_alarm = pcf8563_rtc_read_alarm,
392 .set_alarm = pcf8563_rtc_set_alarm,
393 .alarm_irq_enable = pcf8563_irq_enable,
394 };
395
pcf8563_probe(struct i2c_client * client,const struct i2c_device_id * id)396 static int pcf8563_probe(struct i2c_client *client,
397 const struct i2c_device_id *id)
398 {
399 struct pcf8563 *pcf8563;
400 int err;
401
402 dev_dbg(&client->dev, "%s\n", __func__);
403
404 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
405 return -ENODEV;
406
407 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
408 GFP_KERNEL);
409 if (!pcf8563)
410 return -ENOMEM;
411
412 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
413
414 i2c_set_clientdata(client, pcf8563);
415 pcf8563->client = client;
416 device_set_wakeup_capable(&client->dev, 1);
417
418 pcf8563->rtc = devm_rtc_device_register(&client->dev,
419 pcf8563_driver.driver.name,
420 &pcf8563_rtc_ops, THIS_MODULE);
421
422 if (IS_ERR(pcf8563->rtc))
423 return PTR_ERR(pcf8563->rtc);
424
425 if (client->irq > 0) {
426 err = devm_request_threaded_irq(&client->dev, client->irq,
427 NULL, pcf8563_irq,
428 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
429 pcf8563->rtc->name, client);
430 if (err) {
431 dev_err(&client->dev, "unable to request IRQ %d\n",
432 client->irq);
433 return err;
434 }
435
436 }
437
438 return 0;
439 }
440
441 static const struct i2c_device_id pcf8563_id[] = {
442 { "pcf8563", 0 },
443 { "rtc8564", 0 },
444 { }
445 };
446 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
447
448 #ifdef CONFIG_OF
449 static const struct of_device_id pcf8563_of_match[] = {
450 { .compatible = "nxp,pcf8563" },
451 {}
452 };
453 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
454 #endif
455
456 static struct i2c_driver pcf8563_driver = {
457 .driver = {
458 .name = "rtc-pcf8563",
459 .owner = THIS_MODULE,
460 .of_match_table = of_match_ptr(pcf8563_of_match),
461 },
462 .probe = pcf8563_probe,
463 .id_table = pcf8563_id,
464 };
465
466 module_i2c_driver(pcf8563_driver);
467
468 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
469 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
470 MODULE_LICENSE("GPL");
471 MODULE_VERSION(DRV_VERSION);
472