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Merge tag 'renesas-fixes-for-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / drivers / rtc / rtc-ds1307.c
1 /*
2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
3 *
4 * Copyright (C) 2005 James Chapman (ds1337 core)
5 * Copyright (C) 2006 David Brownell
6 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
7 * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include <linux/bcd.h>
15 #include <linux/i2c.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/rtc/ds1307.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22
23 /*
24 * We can't determine type by probing, but if we expect pre-Linux code
25 * to have set the chip up as a clock (turning on the oscillator and
26 * setting the date and time), Linux can ignore the non-clock features.
27 * That's a natural job for a factory or repair bench.
28 */
29 enum ds_type {
30 ds_1307,
31 ds_1337,
32 ds_1338,
33 ds_1339,
34 ds_1340,
35 ds_1388,
36 ds_3231,
37 m41t00,
38 mcp794xx,
39 rx_8025,
40 last_ds_type /* always last */
41 /* rs5c372 too? different address... */
42 };
43
44
45 /* RTC registers don't differ much, except for the century flag */
46 #define DS1307_REG_SECS 0x00 /* 00-59 */
47 # define DS1307_BIT_CH 0x80
48 # define DS1340_BIT_nEOSC 0x80
49 # define MCP794XX_BIT_ST 0x80
50 #define DS1307_REG_MIN 0x01 /* 00-59 */
51 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
52 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
53 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
54 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
55 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
56 #define DS1307_REG_WDAY 0x03 /* 01-07 */
57 # define MCP794XX_BIT_VBATEN 0x08
58 #define DS1307_REG_MDAY 0x04 /* 01-31 */
59 #define DS1307_REG_MONTH 0x05 /* 01-12 */
60 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
61 #define DS1307_REG_YEAR 0x06 /* 00-99 */
62
63 /*
64 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
65 * start at 7, and they differ a LOT. Only control and status matter for
66 * basic RTC date and time functionality; be careful using them.
67 */
68 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
69 # define DS1307_BIT_OUT 0x80
70 # define DS1338_BIT_OSF 0x20
71 # define DS1307_BIT_SQWE 0x10
72 # define DS1307_BIT_RS1 0x02
73 # define DS1307_BIT_RS0 0x01
74 #define DS1337_REG_CONTROL 0x0e
75 # define DS1337_BIT_nEOSC 0x80
76 # define DS1339_BIT_BBSQI 0x20
77 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
78 # define DS1337_BIT_RS2 0x10
79 # define DS1337_BIT_RS1 0x08
80 # define DS1337_BIT_INTCN 0x04
81 # define DS1337_BIT_A2IE 0x02
82 # define DS1337_BIT_A1IE 0x01
83 #define DS1340_REG_CONTROL 0x07
84 # define DS1340_BIT_OUT 0x80
85 # define DS1340_BIT_FT 0x40
86 # define DS1340_BIT_CALIB_SIGN 0x20
87 # define DS1340_M_CALIBRATION 0x1f
88 #define DS1340_REG_FLAG 0x09
89 # define DS1340_BIT_OSF 0x80
90 #define DS1337_REG_STATUS 0x0f
91 # define DS1337_BIT_OSF 0x80
92 # define DS1337_BIT_A2I 0x02
93 # define DS1337_BIT_A1I 0x01
94 #define DS1339_REG_ALARM1_SECS 0x07
95
96 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
97
98 #define RX8025_REG_CTRL1 0x0e
99 # define RX8025_BIT_2412 0x20
100 #define RX8025_REG_CTRL2 0x0f
101 # define RX8025_BIT_PON 0x10
102 # define RX8025_BIT_VDET 0x40
103 # define RX8025_BIT_XST 0x20
104
105
106 struct ds1307 {
107 u8 offset; /* register's offset */
108 u8 regs[11];
109 u16 nvram_offset;
110 struct bin_attribute *nvram;
111 enum ds_type type;
112 unsigned long flags;
113 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
114 #define HAS_ALARM 1 /* bit 1 == irq claimed */
115 struct i2c_client *client;
116 struct rtc_device *rtc;
117 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
118 u8 length, u8 *values);
119 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
120 u8 length, const u8 *values);
121 };
122
123 struct chip_desc {
124 unsigned alarm:1;
125 u16 nvram_offset;
126 u16 nvram_size;
127 u16 trickle_charger_reg;
128 u8 trickle_charger_setup;
129 u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
130 };
131
132 static u8 do_trickle_setup_ds1339(struct i2c_client *,
133 uint32_t ohms, bool diode);
134
135 static struct chip_desc chips[last_ds_type] = {
136 [ds_1307] = {
137 .nvram_offset = 8,
138 .nvram_size = 56,
139 },
140 [ds_1337] = {
141 .alarm = 1,
142 },
143 [ds_1338] = {
144 .nvram_offset = 8,
145 .nvram_size = 56,
146 },
147 [ds_1339] = {
148 .alarm = 1,
149 .trickle_charger_reg = 0x10,
150 .do_trickle_setup = &do_trickle_setup_ds1339,
151 },
152 [ds_1340] = {
153 .trickle_charger_reg = 0x08,
154 },
155 [ds_1388] = {
156 .trickle_charger_reg = 0x0a,
157 },
158 [ds_3231] = {
159 .alarm = 1,
160 },
161 [mcp794xx] = {
162 .alarm = 1,
163 /* this is battery backed SRAM */
164 .nvram_offset = 0x20,
165 .nvram_size = 0x40,
166 },
167 };
168
169 static const struct i2c_device_id ds1307_id[] = {
170 { "ds1307", ds_1307 },
171 { "ds1337", ds_1337 },
172 { "ds1338", ds_1338 },
173 { "ds1339", ds_1339 },
174 { "ds1388", ds_1388 },
175 { "ds1340", ds_1340 },
176 { "ds3231", ds_3231 },
177 { "m41t00", m41t00 },
178 { "mcp7940x", mcp794xx },
179 { "mcp7941x", mcp794xx },
180 { "pt7c4338", ds_1307 },
181 { "rx8025", rx_8025 },
182 { }
183 };
184 MODULE_DEVICE_TABLE(i2c, ds1307_id);
185
186 /*----------------------------------------------------------------------*/
187
188 #define BLOCK_DATA_MAX_TRIES 10
189
190 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
191 u8 command, u8 length, u8 *values)
192 {
193 s32 i, data;
194
195 for (i = 0; i < length; i++) {
196 data = i2c_smbus_read_byte_data(client, command + i);
197 if (data < 0)
198 return data;
199 values[i] = data;
200 }
201 return i;
202 }
203
204 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
205 u8 length, u8 *values)
206 {
207 u8 oldvalues[255];
208 s32 ret;
209 int tries = 0;
210
211 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
212 ret = ds1307_read_block_data_once(client, command, length, values);
213 if (ret < 0)
214 return ret;
215 do {
216 if (++tries > BLOCK_DATA_MAX_TRIES) {
217 dev_err(&client->dev,
218 "ds1307_read_block_data failed\n");
219 return -EIO;
220 }
221 memcpy(oldvalues, values, length);
222 ret = ds1307_read_block_data_once(client, command, length,
223 values);
224 if (ret < 0)
225 return ret;
226 } while (memcmp(oldvalues, values, length));
227 return length;
228 }
229
230 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
231 u8 length, const u8 *values)
232 {
233 u8 currvalues[255];
234 int tries = 0;
235
236 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
237 do {
238 s32 i, ret;
239
240 if (++tries > BLOCK_DATA_MAX_TRIES) {
241 dev_err(&client->dev,
242 "ds1307_write_block_data failed\n");
243 return -EIO;
244 }
245 for (i = 0; i < length; i++) {
246 ret = i2c_smbus_write_byte_data(client, command + i,
247 values[i]);
248 if (ret < 0)
249 return ret;
250 }
251 ret = ds1307_read_block_data_once(client, command, length,
252 currvalues);
253 if (ret < 0)
254 return ret;
255 } while (memcmp(currvalues, values, length));
256 return length;
257 }
258
259 /*----------------------------------------------------------------------*/
260
261 /* These RTC devices are not designed to be connected to a SMbus adapter.
262 SMbus limits block operations length to 32 bytes, whereas it's not
263 limited on I2C buses. As a result, accesses may exceed 32 bytes;
264 in that case, split them into smaller blocks */
265
266 static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
267 u8 command, u8 length, const u8 *values)
268 {
269 u8 suboffset = 0;
270
271 if (length <= I2C_SMBUS_BLOCK_MAX)
272 return i2c_smbus_write_i2c_block_data(client,
273 command, length, values);
274
275 while (suboffset < length) {
276 s32 retval = i2c_smbus_write_i2c_block_data(client,
277 command + suboffset,
278 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
279 values + suboffset);
280 if (retval < 0)
281 return retval;
282
283 suboffset += I2C_SMBUS_BLOCK_MAX;
284 }
285 return length;
286 }
287
288 static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
289 u8 command, u8 length, u8 *values)
290 {
291 u8 suboffset = 0;
292
293 if (length <= I2C_SMBUS_BLOCK_MAX)
294 return i2c_smbus_read_i2c_block_data(client,
295 command, length, values);
296
297 while (suboffset < length) {
298 s32 retval = i2c_smbus_read_i2c_block_data(client,
299 command + suboffset,
300 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
301 values + suboffset);
302 if (retval < 0)
303 return retval;
304
305 suboffset += I2C_SMBUS_BLOCK_MAX;
306 }
307 return length;
308 }
309
310 /*----------------------------------------------------------------------*/
311
312 /*
313 * The ds1337 and ds1339 both have two alarms, but we only use the first
314 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
315 * signal; ds1339 chips have only one alarm signal.
316 */
317 static irqreturn_t ds1307_irq(int irq, void *dev_id)
318 {
319 struct i2c_client *client = dev_id;
320 struct ds1307 *ds1307 = i2c_get_clientdata(client);
321 struct mutex *lock = &ds1307->rtc->ops_lock;
322 int stat, control;
323
324 mutex_lock(lock);
325 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
326 if (stat < 0)
327 goto out;
328
329 if (stat & DS1337_BIT_A1I) {
330 stat &= ~DS1337_BIT_A1I;
331 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
332
333 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
334 if (control < 0)
335 goto out;
336
337 control &= ~DS1337_BIT_A1IE;
338 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
339
340 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
341 }
342
343 out:
344 mutex_unlock(lock);
345
346 return IRQ_HANDLED;
347 }
348
349 /*----------------------------------------------------------------------*/
350
351 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
352 {
353 struct ds1307 *ds1307 = dev_get_drvdata(dev);
354 int tmp;
355
356 /* read the RTC date and time registers all at once */
357 tmp = ds1307->read_block_data(ds1307->client,
358 ds1307->offset, 7, ds1307->regs);
359 if (tmp != 7) {
360 dev_err(dev, "%s error %d\n", "read", tmp);
361 return -EIO;
362 }
363
364 dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
365
366 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
367 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
368 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
369 t->tm_hour = bcd2bin(tmp);
370 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
371 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
372 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
373 t->tm_mon = bcd2bin(tmp) - 1;
374
375 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
376 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
377
378 dev_dbg(dev, "%s secs=%d, mins=%d, "
379 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
380 "read", t->tm_sec, t->tm_min,
381 t->tm_hour, t->tm_mday,
382 t->tm_mon, t->tm_year, t->tm_wday);
383
384 /* initial clock setting can be undefined */
385 return rtc_valid_tm(t);
386 }
387
388 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
389 {
390 struct ds1307 *ds1307 = dev_get_drvdata(dev);
391 int result;
392 int tmp;
393 u8 *buf = ds1307->regs;
394
395 dev_dbg(dev, "%s secs=%d, mins=%d, "
396 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
397 "write", t->tm_sec, t->tm_min,
398 t->tm_hour, t->tm_mday,
399 t->tm_mon, t->tm_year, t->tm_wday);
400
401 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
402 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
403 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
404 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
405 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
406 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
407
408 /* assume 20YY not 19YY */
409 tmp = t->tm_year - 100;
410 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
411
412 switch (ds1307->type) {
413 case ds_1337:
414 case ds_1339:
415 case ds_3231:
416 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
417 break;
418 case ds_1340:
419 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
420 | DS1340_BIT_CENTURY;
421 break;
422 case mcp794xx:
423 /*
424 * these bits were cleared when preparing the date/time
425 * values and need to be set again before writing the
426 * buffer out to the device.
427 */
428 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
429 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
430 break;
431 default:
432 break;
433 }
434
435 dev_dbg(dev, "%s: %7ph\n", "write", buf);
436
437 result = ds1307->write_block_data(ds1307->client,
438 ds1307->offset, 7, buf);
439 if (result < 0) {
440 dev_err(dev, "%s error %d\n", "write", result);
441 return result;
442 }
443 return 0;
444 }
445
446 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
447 {
448 struct i2c_client *client = to_i2c_client(dev);
449 struct ds1307 *ds1307 = i2c_get_clientdata(client);
450 int ret;
451
452 if (!test_bit(HAS_ALARM, &ds1307->flags))
453 return -EINVAL;
454
455 /* read all ALARM1, ALARM2, and status registers at once */
456 ret = ds1307->read_block_data(client,
457 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
458 if (ret != 9) {
459 dev_err(dev, "%s error %d\n", "alarm read", ret);
460 return -EIO;
461 }
462
463 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
464 "alarm read",
465 ds1307->regs[0], ds1307->regs[1],
466 ds1307->regs[2], ds1307->regs[3],
467 ds1307->regs[4], ds1307->regs[5],
468 ds1307->regs[6], ds1307->regs[7],
469 ds1307->regs[8]);
470
471 /*
472 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
473 * and that all four fields are checked matches
474 */
475 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
476 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
477 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
478 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
479 t->time.tm_mon = -1;
480 t->time.tm_year = -1;
481 t->time.tm_wday = -1;
482 t->time.tm_yday = -1;
483 t->time.tm_isdst = -1;
484
485 /* ... and status */
486 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
487 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
488
489 dev_dbg(dev, "%s secs=%d, mins=%d, "
490 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
491 "alarm read", t->time.tm_sec, t->time.tm_min,
492 t->time.tm_hour, t->time.tm_mday,
493 t->enabled, t->pending);
494
495 return 0;
496 }
497
498 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
499 {
500 struct i2c_client *client = to_i2c_client(dev);
501 struct ds1307 *ds1307 = i2c_get_clientdata(client);
502 unsigned char *buf = ds1307->regs;
503 u8 control, status;
504 int ret;
505
506 if (!test_bit(HAS_ALARM, &ds1307->flags))
507 return -EINVAL;
508
509 dev_dbg(dev, "%s secs=%d, mins=%d, "
510 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
511 "alarm set", t->time.tm_sec, t->time.tm_min,
512 t->time.tm_hour, t->time.tm_mday,
513 t->enabled, t->pending);
514
515 /* read current status of both alarms and the chip */
516 ret = ds1307->read_block_data(client,
517 DS1339_REG_ALARM1_SECS, 9, buf);
518 if (ret != 9) {
519 dev_err(dev, "%s error %d\n", "alarm write", ret);
520 return -EIO;
521 }
522 control = ds1307->regs[7];
523 status = ds1307->regs[8];
524
525 dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
526 "alarm set (old status)",
527 ds1307->regs[0], ds1307->regs[1],
528 ds1307->regs[2], ds1307->regs[3],
529 ds1307->regs[4], ds1307->regs[5],
530 ds1307->regs[6], control, status);
531
532 /* set ALARM1, using 24 hour and day-of-month modes */
533 buf[0] = bin2bcd(t->time.tm_sec);
534 buf[1] = bin2bcd(t->time.tm_min);
535 buf[2] = bin2bcd(t->time.tm_hour);
536 buf[3] = bin2bcd(t->time.tm_mday);
537
538 /* set ALARM2 to non-garbage */
539 buf[4] = 0;
540 buf[5] = 0;
541 buf[6] = 0;
542
543 /* optionally enable ALARM1 */
544 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
545 if (t->enabled) {
546 dev_dbg(dev, "alarm IRQ armed\n");
547 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
548 }
549 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
550
551 ret = ds1307->write_block_data(client,
552 DS1339_REG_ALARM1_SECS, 9, buf);
553 if (ret < 0) {
554 dev_err(dev, "can't set alarm time\n");
555 return ret;
556 }
557
558 return 0;
559 }
560
561 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
562 {
563 struct i2c_client *client = to_i2c_client(dev);
564 struct ds1307 *ds1307 = i2c_get_clientdata(client);
565 int ret;
566
567 if (!test_bit(HAS_ALARM, &ds1307->flags))
568 return -ENOTTY;
569
570 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
571 if (ret < 0)
572 return ret;
573
574 if (enabled)
575 ret |= DS1337_BIT_A1IE;
576 else
577 ret &= ~DS1337_BIT_A1IE;
578
579 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
580 if (ret < 0)
581 return ret;
582
583 return 0;
584 }
585
586 static const struct rtc_class_ops ds13xx_rtc_ops = {
587 .read_time = ds1307_get_time,
588 .set_time = ds1307_set_time,
589 .read_alarm = ds1337_read_alarm,
590 .set_alarm = ds1337_set_alarm,
591 .alarm_irq_enable = ds1307_alarm_irq_enable,
592 };
593
594 /*----------------------------------------------------------------------*/
595
596 /*
597 * Alarm support for mcp794xx devices.
598 */
599
600 #define MCP794XX_REG_CONTROL 0x07
601 # define MCP794XX_BIT_ALM0_EN 0x10
602 # define MCP794XX_BIT_ALM1_EN 0x20
603 #define MCP794XX_REG_ALARM0_BASE 0x0a
604 #define MCP794XX_REG_ALARM0_CTRL 0x0d
605 #define MCP794XX_REG_ALARM1_BASE 0x11
606 #define MCP794XX_REG_ALARM1_CTRL 0x14
607 # define MCP794XX_BIT_ALMX_IF (1 << 3)
608 # define MCP794XX_BIT_ALMX_C0 (1 << 4)
609 # define MCP794XX_BIT_ALMX_C1 (1 << 5)
610 # define MCP794XX_BIT_ALMX_C2 (1 << 6)
611 # define MCP794XX_BIT_ALMX_POL (1 << 7)
612 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
613 MCP794XX_BIT_ALMX_C1 | \
614 MCP794XX_BIT_ALMX_C2)
615
616 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
617 {
618 struct i2c_client *client = dev_id;
619 struct ds1307 *ds1307 = i2c_get_clientdata(client);
620 struct mutex *lock = &ds1307->rtc->ops_lock;
621 int reg, ret;
622
623 mutex_lock(lock);
624
625 /* Check and clear alarm 0 interrupt flag. */
626 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
627 if (reg < 0)
628 goto out;
629 if (!(reg & MCP794XX_BIT_ALMX_IF))
630 goto out;
631 reg &= ~MCP794XX_BIT_ALMX_IF;
632 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
633 if (ret < 0)
634 goto out;
635
636 /* Disable alarm 0. */
637 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
638 if (reg < 0)
639 goto out;
640 reg &= ~MCP794XX_BIT_ALM0_EN;
641 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
642 if (ret < 0)
643 goto out;
644
645 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
646
647 out:
648 mutex_unlock(lock);
649
650 return IRQ_HANDLED;
651 }
652
653 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
654 {
655 struct i2c_client *client = to_i2c_client(dev);
656 struct ds1307 *ds1307 = i2c_get_clientdata(client);
657 u8 *regs = ds1307->regs;
658 int ret;
659
660 if (!test_bit(HAS_ALARM, &ds1307->flags))
661 return -EINVAL;
662
663 /* Read control and alarm 0 registers. */
664 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
665 if (ret < 0)
666 return ret;
667
668 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
669
670 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
671 t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
672 t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
673 t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
674 t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
675 t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
676 t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
677 t->time.tm_year = -1;
678 t->time.tm_yday = -1;
679 t->time.tm_isdst = -1;
680
681 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
682 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
683 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
684 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
685 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
686 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
687 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
688
689 return 0;
690 }
691
692 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
693 {
694 struct i2c_client *client = to_i2c_client(dev);
695 struct ds1307 *ds1307 = i2c_get_clientdata(client);
696 unsigned char *regs = ds1307->regs;
697 int ret;
698
699 if (!test_bit(HAS_ALARM, &ds1307->flags))
700 return -EINVAL;
701
702 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
703 "enabled=%d pending=%d\n", __func__,
704 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
705 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
706 t->enabled, t->pending);
707
708 /* Read control and alarm 0 registers. */
709 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
710 if (ret < 0)
711 return ret;
712
713 /* Set alarm 0, using 24-hour and day-of-month modes. */
714 regs[3] = bin2bcd(t->time.tm_sec);
715 regs[4] = bin2bcd(t->time.tm_min);
716 regs[5] = bin2bcd(t->time.tm_hour);
717 regs[6] = bin2bcd(t->time.tm_wday + 1);
718 regs[7] = bin2bcd(t->time.tm_mday);
719 regs[8] = bin2bcd(t->time.tm_mon + 1);
720
721 /* Clear the alarm 0 interrupt flag. */
722 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
723 /* Set alarm match: second, minute, hour, day, date, month. */
724 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
725 /* Disable interrupt. We will not enable until completely programmed */
726 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
727
728 ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
729 if (ret < 0)
730 return ret;
731
732 if (!t->enabled)
733 return 0;
734 regs[0] |= MCP794XX_BIT_ALM0_EN;
735 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
736 }
737
738 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
739 {
740 struct i2c_client *client = to_i2c_client(dev);
741 struct ds1307 *ds1307 = i2c_get_clientdata(client);
742 int reg;
743
744 if (!test_bit(HAS_ALARM, &ds1307->flags))
745 return -EINVAL;
746
747 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
748 if (reg < 0)
749 return reg;
750
751 if (enabled)
752 reg |= MCP794XX_BIT_ALM0_EN;
753 else
754 reg &= ~MCP794XX_BIT_ALM0_EN;
755
756 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
757 }
758
759 static const struct rtc_class_ops mcp794xx_rtc_ops = {
760 .read_time = ds1307_get_time,
761 .set_time = ds1307_set_time,
762 .read_alarm = mcp794xx_read_alarm,
763 .set_alarm = mcp794xx_set_alarm,
764 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
765 };
766
767 /*----------------------------------------------------------------------*/
768
769 static ssize_t
770 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
771 struct bin_attribute *attr,
772 char *buf, loff_t off, size_t count)
773 {
774 struct i2c_client *client;
775 struct ds1307 *ds1307;
776 int result;
777
778 client = kobj_to_i2c_client(kobj);
779 ds1307 = i2c_get_clientdata(client);
780
781 result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
782 count, buf);
783 if (result < 0)
784 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
785 return result;
786 }
787
788 static ssize_t
789 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
790 struct bin_attribute *attr,
791 char *buf, loff_t off, size_t count)
792 {
793 struct i2c_client *client;
794 struct ds1307 *ds1307;
795 int result;
796
797 client = kobj_to_i2c_client(kobj);
798 ds1307 = i2c_get_clientdata(client);
799
800 result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
801 count, buf);
802 if (result < 0) {
803 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
804 return result;
805 }
806 return count;
807 }
808
809
810 /*----------------------------------------------------------------------*/
811
812 static u8 do_trickle_setup_ds1339(struct i2c_client *client,
813 uint32_t ohms, bool diode)
814 {
815 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
816 DS1307_TRICKLE_CHARGER_NO_DIODE;
817
818 switch (ohms) {
819 case 250:
820 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
821 break;
822 case 2000:
823 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
824 break;
825 case 4000:
826 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
827 break;
828 default:
829 dev_warn(&client->dev,
830 "Unsupported ohm value %u in dt\n", ohms);
831 return 0;
832 }
833 return setup;
834 }
835
836 static void ds1307_trickle_of_init(struct i2c_client *client,
837 struct chip_desc *chip)
838 {
839 uint32_t ohms = 0;
840 bool diode = true;
841
842 if (!chip->do_trickle_setup)
843 goto out;
844 if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
845 goto out;
846 if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
847 diode = false;
848 chip->trickle_charger_setup = chip->do_trickle_setup(client,
849 ohms, diode);
850 out:
851 return;
852 }
853
854 static int ds1307_probe(struct i2c_client *client,
855 const struct i2c_device_id *id)
856 {
857 struct ds1307 *ds1307;
858 int err = -ENODEV;
859 int tmp;
860 struct chip_desc *chip = &chips[id->driver_data];
861 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
862 bool want_irq = false;
863 unsigned char *buf;
864 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
865 irq_handler_t irq_handler = ds1307_irq;
866
867 static const int bbsqi_bitpos[] = {
868 [ds_1337] = 0,
869 [ds_1339] = DS1339_BIT_BBSQI,
870 [ds_3231] = DS3231_BIT_BBSQW,
871 };
872 const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
873
874 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
875 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
876 return -EIO;
877
878 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
879 if (!ds1307)
880 return -ENOMEM;
881
882 i2c_set_clientdata(client, ds1307);
883
884 ds1307->client = client;
885 ds1307->type = id->driver_data;
886
887 if (!pdata && client->dev.of_node)
888 ds1307_trickle_of_init(client, chip);
889 else if (pdata && pdata->trickle_charger_setup)
890 chip->trickle_charger_setup = pdata->trickle_charger_setup;
891
892 if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
893 dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
894 DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
895 chip->trickle_charger_reg);
896 i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
897 DS13XX_TRICKLE_CHARGER_MAGIC |
898 chip->trickle_charger_setup);
899 }
900
901 buf = ds1307->regs;
902 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
903 ds1307->read_block_data = ds1307_native_smbus_read_block_data;
904 ds1307->write_block_data = ds1307_native_smbus_write_block_data;
905 } else {
906 ds1307->read_block_data = ds1307_read_block_data;
907 ds1307->write_block_data = ds1307_write_block_data;
908 }
909
910 switch (ds1307->type) {
911 case ds_1337:
912 case ds_1339:
913 case ds_3231:
914 /* get registers that the "rtc" read below won't read... */
915 tmp = ds1307->read_block_data(ds1307->client,
916 DS1337_REG_CONTROL, 2, buf);
917 if (tmp != 2) {
918 dev_dbg(&client->dev, "read error %d\n", tmp);
919 err = -EIO;
920 goto exit;
921 }
922
923 /* oscillator off? turn it on, so clock can tick. */
924 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
925 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
926
927 /*
928 * Using IRQ? Disable the square wave and both alarms.
929 * For some variants, be sure alarms can trigger when we're
930 * running on Vbackup (BBSQI/BBSQW)
931 */
932 if (ds1307->client->irq > 0 && chip->alarm) {
933 ds1307->regs[0] |= DS1337_BIT_INTCN
934 | bbsqi_bitpos[ds1307->type];
935 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
936
937 want_irq = true;
938 }
939
940 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
941 ds1307->regs[0]);
942
943 /* oscillator fault? clear flag, and warn */
944 if (ds1307->regs[1] & DS1337_BIT_OSF) {
945 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
946 ds1307->regs[1] & ~DS1337_BIT_OSF);
947 dev_warn(&client->dev, "SET TIME!\n");
948 }
949 break;
950
951 case rx_8025:
952 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
953 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
954 if (tmp != 2) {
955 dev_dbg(&client->dev, "read error %d\n", tmp);
956 err = -EIO;
957 goto exit;
958 }
959
960 /* oscillator off? turn it on, so clock can tick. */
961 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
962 ds1307->regs[1] |= RX8025_BIT_XST;
963 i2c_smbus_write_byte_data(client,
964 RX8025_REG_CTRL2 << 4 | 0x08,
965 ds1307->regs[1]);
966 dev_warn(&client->dev,
967 "oscillator stop detected - SET TIME!\n");
968 }
969
970 if (ds1307->regs[1] & RX8025_BIT_PON) {
971 ds1307->regs[1] &= ~RX8025_BIT_PON;
972 i2c_smbus_write_byte_data(client,
973 RX8025_REG_CTRL2 << 4 | 0x08,
974 ds1307->regs[1]);
975 dev_warn(&client->dev, "power-on detected\n");
976 }
977
978 if (ds1307->regs[1] & RX8025_BIT_VDET) {
979 ds1307->regs[1] &= ~RX8025_BIT_VDET;
980 i2c_smbus_write_byte_data(client,
981 RX8025_REG_CTRL2 << 4 | 0x08,
982 ds1307->regs[1]);
983 dev_warn(&client->dev, "voltage drop detected\n");
984 }
985
986 /* make sure we are running in 24hour mode */
987 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
988 u8 hour;
989
990 /* switch to 24 hour mode */
991 i2c_smbus_write_byte_data(client,
992 RX8025_REG_CTRL1 << 4 | 0x08,
993 ds1307->regs[0] |
994 RX8025_BIT_2412);
995
996 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
997 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
998 if (tmp != 2) {
999 dev_dbg(&client->dev, "read error %d\n", tmp);
1000 err = -EIO;
1001 goto exit;
1002 }
1003
1004 /* correct hour */
1005 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1006 if (hour == 12)
1007 hour = 0;
1008 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1009 hour += 12;
1010
1011 i2c_smbus_write_byte_data(client,
1012 DS1307_REG_HOUR << 4 | 0x08,
1013 hour);
1014 }
1015 break;
1016 case ds_1388:
1017 ds1307->offset = 1; /* Seconds starts at 1 */
1018 break;
1019 case mcp794xx:
1020 rtc_ops = &mcp794xx_rtc_ops;
1021 if (ds1307->client->irq > 0 && chip->alarm) {
1022 irq_handler = mcp794xx_irq;
1023 want_irq = true;
1024 }
1025 break;
1026 default:
1027 break;
1028 }
1029
1030 read_rtc:
1031 /* read RTC registers */
1032 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1033 if (tmp != 8) {
1034 dev_dbg(&client->dev, "read error %d\n", tmp);
1035 err = -EIO;
1036 goto exit;
1037 }
1038
1039 /*
1040 * minimal sanity checking; some chips (like DS1340) don't
1041 * specify the extra bits as must-be-zero, but there are
1042 * still a few values that are clearly out-of-range.
1043 */
1044 tmp = ds1307->regs[DS1307_REG_SECS];
1045 switch (ds1307->type) {
1046 case ds_1307:
1047 case m41t00:
1048 /* clock halted? turn it on, so clock can tick. */
1049 if (tmp & DS1307_BIT_CH) {
1050 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1051 dev_warn(&client->dev, "SET TIME!\n");
1052 goto read_rtc;
1053 }
1054 break;
1055 case ds_1338:
1056 /* clock halted? turn it on, so clock can tick. */
1057 if (tmp & DS1307_BIT_CH)
1058 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1059
1060 /* oscillator fault? clear flag, and warn */
1061 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1062 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1063 ds1307->regs[DS1307_REG_CONTROL]
1064 & ~DS1338_BIT_OSF);
1065 dev_warn(&client->dev, "SET TIME!\n");
1066 goto read_rtc;
1067 }
1068 break;
1069 case ds_1340:
1070 /* clock halted? turn it on, so clock can tick. */
1071 if (tmp & DS1340_BIT_nEOSC)
1072 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1073
1074 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1075 if (tmp < 0) {
1076 dev_dbg(&client->dev, "read error %d\n", tmp);
1077 err = -EIO;
1078 goto exit;
1079 }
1080
1081 /* oscillator fault? clear flag, and warn */
1082 if (tmp & DS1340_BIT_OSF) {
1083 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1084 dev_warn(&client->dev, "SET TIME!\n");
1085 }
1086 break;
1087 case mcp794xx:
1088 /* make sure that the backup battery is enabled */
1089 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1090 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1091 ds1307->regs[DS1307_REG_WDAY]
1092 | MCP794XX_BIT_VBATEN);
1093 }
1094
1095 /* clock halted? turn it on, so clock can tick. */
1096 if (!(tmp & MCP794XX_BIT_ST)) {
1097 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1098 MCP794XX_BIT_ST);
1099 dev_warn(&client->dev, "SET TIME!\n");
1100 goto read_rtc;
1101 }
1102
1103 break;
1104 default:
1105 break;
1106 }
1107
1108 tmp = ds1307->regs[DS1307_REG_HOUR];
1109 switch (ds1307->type) {
1110 case ds_1340:
1111 case m41t00:
1112 /*
1113 * NOTE: ignores century bits; fix before deploying
1114 * systems that will run through year 2100.
1115 */
1116 break;
1117 case rx_8025:
1118 break;
1119 default:
1120 if (!(tmp & DS1307_BIT_12HR))
1121 break;
1122
1123 /*
1124 * Be sure we're in 24 hour mode. Multi-master systems
1125 * take note...
1126 */
1127 tmp = bcd2bin(tmp & 0x1f);
1128 if (tmp == 12)
1129 tmp = 0;
1130 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1131 tmp += 12;
1132 i2c_smbus_write_byte_data(client,
1133 ds1307->offset + DS1307_REG_HOUR,
1134 bin2bcd(tmp));
1135 }
1136
1137 if (want_irq) {
1138 device_set_wakeup_capable(&client->dev, true);
1139 set_bit(HAS_ALARM, &ds1307->flags);
1140 }
1141 ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1142 rtc_ops, THIS_MODULE);
1143 if (IS_ERR(ds1307->rtc)) {
1144 return PTR_ERR(ds1307->rtc);
1145 }
1146
1147 if (want_irq) {
1148 err = devm_request_threaded_irq(&client->dev,
1149 client->irq, NULL, irq_handler,
1150 IRQF_SHARED | IRQF_ONESHOT,
1151 ds1307->rtc->name, client);
1152 if (err) {
1153 client->irq = 0;
1154 device_set_wakeup_capable(&client->dev, false);
1155 clear_bit(HAS_ALARM, &ds1307->flags);
1156 dev_err(&client->dev, "unable to request IRQ!\n");
1157 } else
1158 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
1159 }
1160
1161 if (chip->nvram_size) {
1162
1163 ds1307->nvram = devm_kzalloc(&client->dev,
1164 sizeof(struct bin_attribute),
1165 GFP_KERNEL);
1166 if (!ds1307->nvram) {
1167 dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1168 } else {
1169
1170 ds1307->nvram->attr.name = "nvram";
1171 ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1172
1173 sysfs_bin_attr_init(ds1307->nvram);
1174
1175 ds1307->nvram->read = ds1307_nvram_read;
1176 ds1307->nvram->write = ds1307_nvram_write;
1177 ds1307->nvram->size = chip->nvram_size;
1178 ds1307->nvram_offset = chip->nvram_offset;
1179
1180 err = sysfs_create_bin_file(&client->dev.kobj,
1181 ds1307->nvram);
1182 if (err) {
1183 dev_err(&client->dev,
1184 "unable to create sysfs file: %s\n",
1185 ds1307->nvram->attr.name);
1186 } else {
1187 set_bit(HAS_NVRAM, &ds1307->flags);
1188 dev_info(&client->dev, "%zu bytes nvram\n",
1189 ds1307->nvram->size);
1190 }
1191 }
1192 }
1193
1194 return 0;
1195
1196 exit:
1197 return err;
1198 }
1199
1200 static int ds1307_remove(struct i2c_client *client)
1201 {
1202 struct ds1307 *ds1307 = i2c_get_clientdata(client);
1203
1204 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1205 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1206
1207 return 0;
1208 }
1209
1210 static struct i2c_driver ds1307_driver = {
1211 .driver = {
1212 .name = "rtc-ds1307",
1213 },
1214 .probe = ds1307_probe,
1215 .remove = ds1307_remove,
1216 .id_table = ds1307_id,
1217 };
1218
1219 module_i2c_driver(ds1307_driver);
1220
1221 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1222 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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