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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[mirror_ubuntu-zesty-kernel.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 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/clk-provider.h>
25
26 /*
27 * We can't determine type by probing, but if we expect pre-Linux code
28 * to have set the chip up as a clock (turning on the oscillator and
29 * setting the date and time), Linux can ignore the non-clock features.
30 * That's a natural job for a factory or repair bench.
31 */
32 enum ds_type {
33 ds_1307,
34 ds_1337,
35 ds_1338,
36 ds_1339,
37 ds_1340,
38 ds_1388,
39 ds_3231,
40 m41t00,
41 mcp794xx,
42 rx_8025,
43 last_ds_type /* always last */
44 /* rs5c372 too? different address... */
45 };
46
47
48 /* RTC registers don't differ much, except for the century flag */
49 #define DS1307_REG_SECS 0x00 /* 00-59 */
50 # define DS1307_BIT_CH 0x80
51 # define DS1340_BIT_nEOSC 0x80
52 # define MCP794XX_BIT_ST 0x80
53 #define DS1307_REG_MIN 0x01 /* 00-59 */
54 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
55 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
56 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
57 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
58 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
59 #define DS1307_REG_WDAY 0x03 /* 01-07 */
60 # define MCP794XX_BIT_VBATEN 0x08
61 #define DS1307_REG_MDAY 0x04 /* 01-31 */
62 #define DS1307_REG_MONTH 0x05 /* 01-12 */
63 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
64 #define DS1307_REG_YEAR 0x06 /* 00-99 */
65
66 /*
67 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
68 * start at 7, and they differ a LOT. Only control and status matter for
69 * basic RTC date and time functionality; be careful using them.
70 */
71 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
72 # define DS1307_BIT_OUT 0x80
73 # define DS1338_BIT_OSF 0x20
74 # define DS1307_BIT_SQWE 0x10
75 # define DS1307_BIT_RS1 0x02
76 # define DS1307_BIT_RS0 0x01
77 #define DS1337_REG_CONTROL 0x0e
78 # define DS1337_BIT_nEOSC 0x80
79 # define DS1339_BIT_BBSQI 0x20
80 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
81 # define DS1337_BIT_RS2 0x10
82 # define DS1337_BIT_RS1 0x08
83 # define DS1337_BIT_INTCN 0x04
84 # define DS1337_BIT_A2IE 0x02
85 # define DS1337_BIT_A1IE 0x01
86 #define DS1340_REG_CONTROL 0x07
87 # define DS1340_BIT_OUT 0x80
88 # define DS1340_BIT_FT 0x40
89 # define DS1340_BIT_CALIB_SIGN 0x20
90 # define DS1340_M_CALIBRATION 0x1f
91 #define DS1340_REG_FLAG 0x09
92 # define DS1340_BIT_OSF 0x80
93 #define DS1337_REG_STATUS 0x0f
94 # define DS1337_BIT_OSF 0x80
95 # define DS3231_BIT_EN32KHZ 0x08
96 # define DS1337_BIT_A2I 0x02
97 # define DS1337_BIT_A1I 0x01
98 #define DS1339_REG_ALARM1_SECS 0x07
99
100 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
101
102 #define RX8025_REG_CTRL1 0x0e
103 # define RX8025_BIT_2412 0x20
104 #define RX8025_REG_CTRL2 0x0f
105 # define RX8025_BIT_PON 0x10
106 # define RX8025_BIT_VDET 0x40
107 # define RX8025_BIT_XST 0x20
108
109
110 struct ds1307 {
111 u8 offset; /* register's offset */
112 u8 regs[11];
113 u16 nvram_offset;
114 struct bin_attribute *nvram;
115 enum ds_type type;
116 unsigned long flags;
117 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
118 #define HAS_ALARM 1 /* bit 1 == irq claimed */
119 struct i2c_client *client;
120 struct rtc_device *rtc;
121 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
122 u8 length, u8 *values);
123 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
124 u8 length, const u8 *values);
125 #ifdef CONFIG_COMMON_CLK
126 struct clk_hw clks[2];
127 #endif
128 };
129
130 struct chip_desc {
131 unsigned alarm:1;
132 u16 nvram_offset;
133 u16 nvram_size;
134 u16 trickle_charger_reg;
135 u8 trickle_charger_setup;
136 u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
137 };
138
139 static u8 do_trickle_setup_ds1339(struct i2c_client *,
140 uint32_t ohms, bool diode);
141
142 static struct chip_desc chips[last_ds_type] = {
143 [ds_1307] = {
144 .nvram_offset = 8,
145 .nvram_size = 56,
146 },
147 [ds_1337] = {
148 .alarm = 1,
149 },
150 [ds_1338] = {
151 .nvram_offset = 8,
152 .nvram_size = 56,
153 },
154 [ds_1339] = {
155 .alarm = 1,
156 .trickle_charger_reg = 0x10,
157 .do_trickle_setup = &do_trickle_setup_ds1339,
158 },
159 [ds_1340] = {
160 .trickle_charger_reg = 0x08,
161 },
162 [ds_1388] = {
163 .trickle_charger_reg = 0x0a,
164 },
165 [ds_3231] = {
166 .alarm = 1,
167 },
168 [mcp794xx] = {
169 .alarm = 1,
170 /* this is battery backed SRAM */
171 .nvram_offset = 0x20,
172 .nvram_size = 0x40,
173 },
174 };
175
176 static const struct i2c_device_id ds1307_id[] = {
177 { "ds1307", ds_1307 },
178 { "ds1337", ds_1337 },
179 { "ds1338", ds_1338 },
180 { "ds1339", ds_1339 },
181 { "ds1388", ds_1388 },
182 { "ds1340", ds_1340 },
183 { "ds3231", ds_3231 },
184 { "m41t00", m41t00 },
185 { "mcp7940x", mcp794xx },
186 { "mcp7941x", mcp794xx },
187 { "pt7c4338", ds_1307 },
188 { "rx8025", rx_8025 },
189 { }
190 };
191 MODULE_DEVICE_TABLE(i2c, ds1307_id);
192
193 /*----------------------------------------------------------------------*/
194
195 #define BLOCK_DATA_MAX_TRIES 10
196
197 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
198 u8 command, u8 length, u8 *values)
199 {
200 s32 i, data;
201
202 for (i = 0; i < length; i++) {
203 data = i2c_smbus_read_byte_data(client, command + i);
204 if (data < 0)
205 return data;
206 values[i] = data;
207 }
208 return i;
209 }
210
211 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
212 u8 length, u8 *values)
213 {
214 u8 oldvalues[255];
215 s32 ret;
216 int tries = 0;
217
218 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
219 ret = ds1307_read_block_data_once(client, command, length, values);
220 if (ret < 0)
221 return ret;
222 do {
223 if (++tries > BLOCK_DATA_MAX_TRIES) {
224 dev_err(&client->dev,
225 "ds1307_read_block_data failed\n");
226 return -EIO;
227 }
228 memcpy(oldvalues, values, length);
229 ret = ds1307_read_block_data_once(client, command, length,
230 values);
231 if (ret < 0)
232 return ret;
233 } while (memcmp(oldvalues, values, length));
234 return length;
235 }
236
237 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
238 u8 length, const u8 *values)
239 {
240 u8 currvalues[255];
241 int tries = 0;
242
243 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
244 do {
245 s32 i, ret;
246
247 if (++tries > BLOCK_DATA_MAX_TRIES) {
248 dev_err(&client->dev,
249 "ds1307_write_block_data failed\n");
250 return -EIO;
251 }
252 for (i = 0; i < length; i++) {
253 ret = i2c_smbus_write_byte_data(client, command + i,
254 values[i]);
255 if (ret < 0)
256 return ret;
257 }
258 ret = ds1307_read_block_data_once(client, command, length,
259 currvalues);
260 if (ret < 0)
261 return ret;
262 } while (memcmp(currvalues, values, length));
263 return length;
264 }
265
266 /*----------------------------------------------------------------------*/
267
268 /* These RTC devices are not designed to be connected to a SMbus adapter.
269 SMbus limits block operations length to 32 bytes, whereas it's not
270 limited on I2C buses. As a result, accesses may exceed 32 bytes;
271 in that case, split them into smaller blocks */
272
273 static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
274 u8 command, u8 length, const u8 *values)
275 {
276 u8 suboffset = 0;
277
278 if (length <= I2C_SMBUS_BLOCK_MAX) {
279 s32 retval = i2c_smbus_write_i2c_block_data(client,
280 command, length, values);
281 if (retval < 0)
282 return retval;
283 return length;
284 }
285
286 while (suboffset < length) {
287 s32 retval = i2c_smbus_write_i2c_block_data(client,
288 command + suboffset,
289 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
290 values + suboffset);
291 if (retval < 0)
292 return retval;
293
294 suboffset += I2C_SMBUS_BLOCK_MAX;
295 }
296 return length;
297 }
298
299 static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
300 u8 command, u8 length, u8 *values)
301 {
302 u8 suboffset = 0;
303
304 if (length <= I2C_SMBUS_BLOCK_MAX)
305 return i2c_smbus_read_i2c_block_data(client,
306 command, length, values);
307
308 while (suboffset < length) {
309 s32 retval = i2c_smbus_read_i2c_block_data(client,
310 command + suboffset,
311 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
312 values + suboffset);
313 if (retval < 0)
314 return retval;
315
316 suboffset += I2C_SMBUS_BLOCK_MAX;
317 }
318 return length;
319 }
320
321 /*----------------------------------------------------------------------*/
322
323 /*
324 * The ds1337 and ds1339 both have two alarms, but we only use the first
325 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
326 * signal; ds1339 chips have only one alarm signal.
327 */
328 static irqreturn_t ds1307_irq(int irq, void *dev_id)
329 {
330 struct i2c_client *client = dev_id;
331 struct ds1307 *ds1307 = i2c_get_clientdata(client);
332 struct mutex *lock = &ds1307->rtc->ops_lock;
333 int stat, control;
334
335 mutex_lock(lock);
336 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
337 if (stat < 0)
338 goto out;
339
340 if (stat & DS1337_BIT_A1I) {
341 stat &= ~DS1337_BIT_A1I;
342 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
343
344 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
345 if (control < 0)
346 goto out;
347
348 control &= ~DS1337_BIT_A1IE;
349 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
350
351 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
352 }
353
354 out:
355 mutex_unlock(lock);
356
357 return IRQ_HANDLED;
358 }
359
360 /*----------------------------------------------------------------------*/
361
362 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
363 {
364 struct ds1307 *ds1307 = dev_get_drvdata(dev);
365 int tmp;
366
367 /* read the RTC date and time registers all at once */
368 tmp = ds1307->read_block_data(ds1307->client,
369 ds1307->offset, 7, ds1307->regs);
370 if (tmp != 7) {
371 dev_err(dev, "%s error %d\n", "read", tmp);
372 return -EIO;
373 }
374
375 dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
376
377 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
378 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
379 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
380 t->tm_hour = bcd2bin(tmp);
381 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
382 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
383 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
384 t->tm_mon = bcd2bin(tmp) - 1;
385
386 /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
387 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
388
389 dev_dbg(dev, "%s secs=%d, mins=%d, "
390 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
391 "read", t->tm_sec, t->tm_min,
392 t->tm_hour, t->tm_mday,
393 t->tm_mon, t->tm_year, t->tm_wday);
394
395 /* initial clock setting can be undefined */
396 return rtc_valid_tm(t);
397 }
398
399 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
400 {
401 struct ds1307 *ds1307 = dev_get_drvdata(dev);
402 int result;
403 int tmp;
404 u8 *buf = ds1307->regs;
405
406 dev_dbg(dev, "%s secs=%d, mins=%d, "
407 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
408 "write", t->tm_sec, t->tm_min,
409 t->tm_hour, t->tm_mday,
410 t->tm_mon, t->tm_year, t->tm_wday);
411
412 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
413 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
414 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
415 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
416 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
417 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
418
419 /* assume 20YY not 19YY */
420 tmp = t->tm_year - 100;
421 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
422
423 switch (ds1307->type) {
424 case ds_1337:
425 case ds_1339:
426 case ds_3231:
427 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
428 break;
429 case ds_1340:
430 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
431 | DS1340_BIT_CENTURY;
432 break;
433 case mcp794xx:
434 /*
435 * these bits were cleared when preparing the date/time
436 * values and need to be set again before writing the
437 * buffer out to the device.
438 */
439 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
440 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
441 break;
442 default:
443 break;
444 }
445
446 dev_dbg(dev, "%s: %7ph\n", "write", buf);
447
448 result = ds1307->write_block_data(ds1307->client,
449 ds1307->offset, 7, buf);
450 if (result < 0) {
451 dev_err(dev, "%s error %d\n", "write", result);
452 return result;
453 }
454 return 0;
455 }
456
457 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
458 {
459 struct i2c_client *client = to_i2c_client(dev);
460 struct ds1307 *ds1307 = i2c_get_clientdata(client);
461 int ret;
462
463 if (!test_bit(HAS_ALARM, &ds1307->flags))
464 return -EINVAL;
465
466 /* read all ALARM1, ALARM2, and status registers at once */
467 ret = ds1307->read_block_data(client,
468 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
469 if (ret != 9) {
470 dev_err(dev, "%s error %d\n", "alarm read", ret);
471 return -EIO;
472 }
473
474 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
475 &ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
476
477 /*
478 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
479 * and that all four fields are checked matches
480 */
481 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
482 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
483 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
484 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
485 t->time.tm_mon = -1;
486 t->time.tm_year = -1;
487 t->time.tm_wday = -1;
488 t->time.tm_yday = -1;
489 t->time.tm_isdst = -1;
490
491 /* ... and status */
492 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
493 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
494
495 dev_dbg(dev, "%s secs=%d, mins=%d, "
496 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
497 "alarm read", t->time.tm_sec, t->time.tm_min,
498 t->time.tm_hour, t->time.tm_mday,
499 t->enabled, t->pending);
500
501 return 0;
502 }
503
504 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
505 {
506 struct i2c_client *client = to_i2c_client(dev);
507 struct ds1307 *ds1307 = i2c_get_clientdata(client);
508 unsigned char *buf = ds1307->regs;
509 u8 control, status;
510 int ret;
511
512 if (!test_bit(HAS_ALARM, &ds1307->flags))
513 return -EINVAL;
514
515 dev_dbg(dev, "%s secs=%d, mins=%d, "
516 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
517 "alarm set", t->time.tm_sec, t->time.tm_min,
518 t->time.tm_hour, t->time.tm_mday,
519 t->enabled, t->pending);
520
521 /* read current status of both alarms and the chip */
522 ret = ds1307->read_block_data(client,
523 DS1339_REG_ALARM1_SECS, 9, buf);
524 if (ret != 9) {
525 dev_err(dev, "%s error %d\n", "alarm write", ret);
526 return -EIO;
527 }
528 control = ds1307->regs[7];
529 status = ds1307->regs[8];
530
531 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
532 &ds1307->regs[0], &ds1307->regs[4], control, status);
533
534 /* set ALARM1, using 24 hour and day-of-month modes */
535 buf[0] = bin2bcd(t->time.tm_sec);
536 buf[1] = bin2bcd(t->time.tm_min);
537 buf[2] = bin2bcd(t->time.tm_hour);
538 buf[3] = bin2bcd(t->time.tm_mday);
539
540 /* set ALARM2 to non-garbage */
541 buf[4] = 0;
542 buf[5] = 0;
543 buf[6] = 0;
544
545 /* disable alarms */
546 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
547 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
548
549 ret = ds1307->write_block_data(client,
550 DS1339_REG_ALARM1_SECS, 9, buf);
551 if (ret < 0) {
552 dev_err(dev, "can't set alarm time\n");
553 return ret;
554 }
555
556 /* optionally enable ALARM1 */
557 if (t->enabled) {
558 dev_dbg(dev, "alarm IRQ armed\n");
559 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
560 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, buf[7]);
561 }
562
563 return 0;
564 }
565
566 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
567 {
568 struct i2c_client *client = to_i2c_client(dev);
569 struct ds1307 *ds1307 = i2c_get_clientdata(client);
570 int ret;
571
572 if (!test_bit(HAS_ALARM, &ds1307->flags))
573 return -ENOTTY;
574
575 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
576 if (ret < 0)
577 return ret;
578
579 if (enabled)
580 ret |= DS1337_BIT_A1IE;
581 else
582 ret &= ~DS1337_BIT_A1IE;
583
584 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
585 if (ret < 0)
586 return ret;
587
588 return 0;
589 }
590
591 static const struct rtc_class_ops ds13xx_rtc_ops = {
592 .read_time = ds1307_get_time,
593 .set_time = ds1307_set_time,
594 .read_alarm = ds1337_read_alarm,
595 .set_alarm = ds1337_set_alarm,
596 .alarm_irq_enable = ds1307_alarm_irq_enable,
597 };
598
599 /*----------------------------------------------------------------------*/
600
601 /*
602 * Alarm support for mcp794xx devices.
603 */
604
605 #define MCP794XX_REG_CONTROL 0x07
606 # define MCP794XX_BIT_ALM0_EN 0x10
607 # define MCP794XX_BIT_ALM1_EN 0x20
608 #define MCP794XX_REG_ALARM0_BASE 0x0a
609 #define MCP794XX_REG_ALARM0_CTRL 0x0d
610 #define MCP794XX_REG_ALARM1_BASE 0x11
611 #define MCP794XX_REG_ALARM1_CTRL 0x14
612 # define MCP794XX_BIT_ALMX_IF (1 << 3)
613 # define MCP794XX_BIT_ALMX_C0 (1 << 4)
614 # define MCP794XX_BIT_ALMX_C1 (1 << 5)
615 # define MCP794XX_BIT_ALMX_C2 (1 << 6)
616 # define MCP794XX_BIT_ALMX_POL (1 << 7)
617 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
618 MCP794XX_BIT_ALMX_C1 | \
619 MCP794XX_BIT_ALMX_C2)
620
621 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
622 {
623 struct i2c_client *client = dev_id;
624 struct ds1307 *ds1307 = i2c_get_clientdata(client);
625 struct mutex *lock = &ds1307->rtc->ops_lock;
626 int reg, ret;
627
628 mutex_lock(lock);
629
630 /* Check and clear alarm 0 interrupt flag. */
631 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
632 if (reg < 0)
633 goto out;
634 if (!(reg & MCP794XX_BIT_ALMX_IF))
635 goto out;
636 reg &= ~MCP794XX_BIT_ALMX_IF;
637 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
638 if (ret < 0)
639 goto out;
640
641 /* Disable alarm 0. */
642 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
643 if (reg < 0)
644 goto out;
645 reg &= ~MCP794XX_BIT_ALM0_EN;
646 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
647 if (ret < 0)
648 goto out;
649
650 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
651
652 out:
653 mutex_unlock(lock);
654
655 return IRQ_HANDLED;
656 }
657
658 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
659 {
660 struct i2c_client *client = to_i2c_client(dev);
661 struct ds1307 *ds1307 = i2c_get_clientdata(client);
662 u8 *regs = ds1307->regs;
663 int ret;
664
665 if (!test_bit(HAS_ALARM, &ds1307->flags))
666 return -EINVAL;
667
668 /* Read control and alarm 0 registers. */
669 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
670 if (ret < 0)
671 return ret;
672
673 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
674
675 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
676 t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
677 t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
678 t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
679 t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
680 t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
681 t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
682 t->time.tm_year = -1;
683 t->time.tm_yday = -1;
684 t->time.tm_isdst = -1;
685
686 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
687 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
688 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
689 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
690 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
691 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
692 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
693
694 return 0;
695 }
696
697 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
698 {
699 struct i2c_client *client = to_i2c_client(dev);
700 struct ds1307 *ds1307 = i2c_get_clientdata(client);
701 unsigned char *regs = ds1307->regs;
702 int ret;
703
704 if (!test_bit(HAS_ALARM, &ds1307->flags))
705 return -EINVAL;
706
707 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
708 "enabled=%d pending=%d\n", __func__,
709 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
710 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
711 t->enabled, t->pending);
712
713 /* Read control and alarm 0 registers. */
714 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
715 if (ret < 0)
716 return ret;
717
718 /* Set alarm 0, using 24-hour and day-of-month modes. */
719 regs[3] = bin2bcd(t->time.tm_sec);
720 regs[4] = bin2bcd(t->time.tm_min);
721 regs[5] = bin2bcd(t->time.tm_hour);
722 regs[6] = bin2bcd(t->time.tm_wday + 1);
723 regs[7] = bin2bcd(t->time.tm_mday);
724 regs[8] = bin2bcd(t->time.tm_mon + 1);
725
726 /* Clear the alarm 0 interrupt flag. */
727 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
728 /* Set alarm match: second, minute, hour, day, date, month. */
729 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
730 /* Disable interrupt. We will not enable until completely programmed */
731 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
732
733 ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
734 if (ret < 0)
735 return ret;
736
737 if (!t->enabled)
738 return 0;
739 regs[0] |= MCP794XX_BIT_ALM0_EN;
740 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
741 }
742
743 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
744 {
745 struct i2c_client *client = to_i2c_client(dev);
746 struct ds1307 *ds1307 = i2c_get_clientdata(client);
747 int reg;
748
749 if (!test_bit(HAS_ALARM, &ds1307->flags))
750 return -EINVAL;
751
752 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
753 if (reg < 0)
754 return reg;
755
756 if (enabled)
757 reg |= MCP794XX_BIT_ALM0_EN;
758 else
759 reg &= ~MCP794XX_BIT_ALM0_EN;
760
761 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
762 }
763
764 static const struct rtc_class_ops mcp794xx_rtc_ops = {
765 .read_time = ds1307_get_time,
766 .set_time = ds1307_set_time,
767 .read_alarm = mcp794xx_read_alarm,
768 .set_alarm = mcp794xx_set_alarm,
769 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
770 };
771
772 /*----------------------------------------------------------------------*/
773
774 static ssize_t
775 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
776 struct bin_attribute *attr,
777 char *buf, loff_t off, size_t count)
778 {
779 struct i2c_client *client;
780 struct ds1307 *ds1307;
781 int result;
782
783 client = kobj_to_i2c_client(kobj);
784 ds1307 = i2c_get_clientdata(client);
785
786 result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
787 count, buf);
788 if (result < 0)
789 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
790 return result;
791 }
792
793 static ssize_t
794 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
795 struct bin_attribute *attr,
796 char *buf, loff_t off, size_t count)
797 {
798 struct i2c_client *client;
799 struct ds1307 *ds1307;
800 int result;
801
802 client = kobj_to_i2c_client(kobj);
803 ds1307 = i2c_get_clientdata(client);
804
805 result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
806 count, buf);
807 if (result < 0) {
808 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
809 return result;
810 }
811 return count;
812 }
813
814
815 /*----------------------------------------------------------------------*/
816
817 static u8 do_trickle_setup_ds1339(struct i2c_client *client,
818 uint32_t ohms, bool diode)
819 {
820 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
821 DS1307_TRICKLE_CHARGER_NO_DIODE;
822
823 switch (ohms) {
824 case 250:
825 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
826 break;
827 case 2000:
828 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
829 break;
830 case 4000:
831 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
832 break;
833 default:
834 dev_warn(&client->dev,
835 "Unsupported ohm value %u in dt\n", ohms);
836 return 0;
837 }
838 return setup;
839 }
840
841 static void ds1307_trickle_of_init(struct i2c_client *client,
842 struct chip_desc *chip)
843 {
844 uint32_t ohms = 0;
845 bool diode = true;
846
847 if (!chip->do_trickle_setup)
848 goto out;
849 if (of_property_read_u32(client->dev.of_node, "trickle-resistor-ohms" , &ohms))
850 goto out;
851 if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
852 diode = false;
853 chip->trickle_charger_setup = chip->do_trickle_setup(client,
854 ohms, diode);
855 out:
856 return;
857 }
858
859 /*----------------------------------------------------------------------*/
860
861 #ifdef CONFIG_RTC_DRV_DS1307_HWMON
862
863 /*
864 * Temperature sensor support for ds3231 devices.
865 */
866
867 #define DS3231_REG_TEMPERATURE 0x11
868
869 /*
870 * A user-initiated temperature conversion is not started by this function,
871 * so the temperature is updated once every 64 seconds.
872 */
873 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
874 {
875 struct ds1307 *ds1307 = dev_get_drvdata(dev);
876 u8 temp_buf[2];
877 s16 temp;
878 int ret;
879
880 ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE,
881 sizeof(temp_buf), temp_buf);
882 if (ret < 0)
883 return ret;
884 if (ret != sizeof(temp_buf))
885 return -EIO;
886
887 /*
888 * Temperature is represented as a 10-bit code with a resolution of
889 * 0.25 degree celsius and encoded in two's complement format.
890 */
891 temp = (temp_buf[0] << 8) | temp_buf[1];
892 temp >>= 6;
893 *mC = temp * 250;
894
895 return 0;
896 }
897
898 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
899 struct device_attribute *attr, char *buf)
900 {
901 int ret;
902 s32 temp;
903
904 ret = ds3231_hwmon_read_temp(dev, &temp);
905 if (ret)
906 return ret;
907
908 return sprintf(buf, "%d\n", temp);
909 }
910 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp,
911 NULL, 0);
912
913 static struct attribute *ds3231_hwmon_attrs[] = {
914 &sensor_dev_attr_temp1_input.dev_attr.attr,
915 NULL,
916 };
917 ATTRIBUTE_GROUPS(ds3231_hwmon);
918
919 static void ds1307_hwmon_register(struct ds1307 *ds1307)
920 {
921 struct device *dev;
922
923 if (ds1307->type != ds_3231)
924 return;
925
926 dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev,
927 ds1307->client->name,
928 ds1307, ds3231_hwmon_groups);
929 if (IS_ERR(dev)) {
930 dev_warn(&ds1307->client->dev,
931 "unable to register hwmon device %ld\n", PTR_ERR(dev));
932 }
933 }
934
935 #else
936
937 static void ds1307_hwmon_register(struct ds1307 *ds1307)
938 {
939 }
940
941 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
942
943 /*----------------------------------------------------------------------*/
944
945 /*
946 * Square-wave output support for DS3231
947 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
948 */
949 #ifdef CONFIG_COMMON_CLK
950
951 enum {
952 DS3231_CLK_SQW = 0,
953 DS3231_CLK_32KHZ,
954 };
955
956 #define clk_sqw_to_ds1307(clk) \
957 container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
958 #define clk_32khz_to_ds1307(clk) \
959 container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
960
961 static int ds3231_clk_sqw_rates[] = {
962 1,
963 1024,
964 4096,
965 8192,
966 };
967
968 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
969 {
970 struct i2c_client *client = ds1307->client;
971 struct mutex *lock = &ds1307->rtc->ops_lock;
972 int control;
973 int ret;
974
975 mutex_lock(lock);
976
977 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
978 if (control < 0) {
979 ret = control;
980 goto out;
981 }
982
983 control &= ~mask;
984 control |= value;
985
986 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
987 out:
988 mutex_unlock(lock);
989
990 return ret;
991 }
992
993 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
994 unsigned long parent_rate)
995 {
996 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
997 int control;
998 int rate_sel = 0;
999
1000 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1001 if (control < 0)
1002 return control;
1003 if (control & DS1337_BIT_RS1)
1004 rate_sel += 1;
1005 if (control & DS1337_BIT_RS2)
1006 rate_sel += 2;
1007
1008 return ds3231_clk_sqw_rates[rate_sel];
1009 }
1010
1011 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1012 unsigned long *prate)
1013 {
1014 int i;
1015
1016 for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1017 if (ds3231_clk_sqw_rates[i] <= rate)
1018 return ds3231_clk_sqw_rates[i];
1019 }
1020
1021 return 0;
1022 }
1023
1024 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1025 unsigned long parent_rate)
1026 {
1027 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1028 int control = 0;
1029 int rate_sel;
1030
1031 for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1032 rate_sel++) {
1033 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1034 break;
1035 }
1036
1037 if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1038 return -EINVAL;
1039
1040 if (rate_sel & 1)
1041 control |= DS1337_BIT_RS1;
1042 if (rate_sel & 2)
1043 control |= DS1337_BIT_RS2;
1044
1045 return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1046 control);
1047 }
1048
1049 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1050 {
1051 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1052
1053 return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1054 }
1055
1056 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1057 {
1058 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1059
1060 ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1061 }
1062
1063 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1064 {
1065 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1066 int control;
1067
1068 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1069 if (control < 0)
1070 return control;
1071
1072 return !(control & DS1337_BIT_INTCN);
1073 }
1074
1075 static const struct clk_ops ds3231_clk_sqw_ops = {
1076 .prepare = ds3231_clk_sqw_prepare,
1077 .unprepare = ds3231_clk_sqw_unprepare,
1078 .is_prepared = ds3231_clk_sqw_is_prepared,
1079 .recalc_rate = ds3231_clk_sqw_recalc_rate,
1080 .round_rate = ds3231_clk_sqw_round_rate,
1081 .set_rate = ds3231_clk_sqw_set_rate,
1082 };
1083
1084 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1085 unsigned long parent_rate)
1086 {
1087 return 32768;
1088 }
1089
1090 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1091 {
1092 struct i2c_client *client = ds1307->client;
1093 struct mutex *lock = &ds1307->rtc->ops_lock;
1094 int status;
1095 int ret;
1096
1097 mutex_lock(lock);
1098
1099 status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
1100 if (status < 0) {
1101 ret = status;
1102 goto out;
1103 }
1104
1105 if (enable)
1106 status |= DS3231_BIT_EN32KHZ;
1107 else
1108 status &= ~DS3231_BIT_EN32KHZ;
1109
1110 ret = i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, status);
1111 out:
1112 mutex_unlock(lock);
1113
1114 return ret;
1115 }
1116
1117 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1118 {
1119 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1120
1121 return ds3231_clk_32khz_control(ds1307, true);
1122 }
1123
1124 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1125 {
1126 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1127
1128 ds3231_clk_32khz_control(ds1307, false);
1129 }
1130
1131 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1132 {
1133 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1134 int status;
1135
1136 status = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_STATUS);
1137 if (status < 0)
1138 return status;
1139
1140 return !!(status & DS3231_BIT_EN32KHZ);
1141 }
1142
1143 static const struct clk_ops ds3231_clk_32khz_ops = {
1144 .prepare = ds3231_clk_32khz_prepare,
1145 .unprepare = ds3231_clk_32khz_unprepare,
1146 .is_prepared = ds3231_clk_32khz_is_prepared,
1147 .recalc_rate = ds3231_clk_32khz_recalc_rate,
1148 };
1149
1150 static struct clk_init_data ds3231_clks_init[] = {
1151 [DS3231_CLK_SQW] = {
1152 .name = "ds3231_clk_sqw",
1153 .ops = &ds3231_clk_sqw_ops,
1154 },
1155 [DS3231_CLK_32KHZ] = {
1156 .name = "ds3231_clk_32khz",
1157 .ops = &ds3231_clk_32khz_ops,
1158 },
1159 };
1160
1161 static int ds3231_clks_register(struct ds1307 *ds1307)
1162 {
1163 struct i2c_client *client = ds1307->client;
1164 struct device_node *node = client->dev.of_node;
1165 struct clk_onecell_data *onecell;
1166 int i;
1167
1168 onecell = devm_kzalloc(&client->dev, sizeof(*onecell), GFP_KERNEL);
1169 if (!onecell)
1170 return -ENOMEM;
1171
1172 onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1173 onecell->clks = devm_kcalloc(&client->dev, onecell->clk_num,
1174 sizeof(onecell->clks[0]), GFP_KERNEL);
1175 if (!onecell->clks)
1176 return -ENOMEM;
1177
1178 for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1179 struct clk_init_data init = ds3231_clks_init[i];
1180
1181 /*
1182 * Interrupt signal due to alarm conditions and square-wave
1183 * output share same pin, so don't initialize both.
1184 */
1185 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1186 continue;
1187
1188 /* optional override of the clockname */
1189 of_property_read_string_index(node, "clock-output-names", i,
1190 &init.name);
1191 ds1307->clks[i].init = &init;
1192
1193 onecell->clks[i] = devm_clk_register(&client->dev,
1194 &ds1307->clks[i]);
1195 if (IS_ERR(onecell->clks[i]))
1196 return PTR_ERR(onecell->clks[i]);
1197 }
1198
1199 if (!node)
1200 return 0;
1201
1202 of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1203
1204 return 0;
1205 }
1206
1207 static void ds1307_clks_register(struct ds1307 *ds1307)
1208 {
1209 int ret;
1210
1211 if (ds1307->type != ds_3231)
1212 return;
1213
1214 ret = ds3231_clks_register(ds1307);
1215 if (ret) {
1216 dev_warn(&ds1307->client->dev,
1217 "unable to register clock device %d\n", ret);
1218 }
1219 }
1220
1221 #else
1222
1223 static void ds1307_clks_register(struct ds1307 *ds1307)
1224 {
1225 }
1226
1227 #endif /* CONFIG_COMMON_CLK */
1228
1229 static int ds1307_probe(struct i2c_client *client,
1230 const struct i2c_device_id *id)
1231 {
1232 struct ds1307 *ds1307;
1233 int err = -ENODEV;
1234 int tmp;
1235 struct chip_desc *chip = &chips[id->driver_data];
1236 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
1237 bool want_irq = false;
1238 bool ds1307_can_wakeup_device = false;
1239 unsigned char *buf;
1240 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1241 irq_handler_t irq_handler = ds1307_irq;
1242
1243 static const int bbsqi_bitpos[] = {
1244 [ds_1337] = 0,
1245 [ds_1339] = DS1339_BIT_BBSQI,
1246 [ds_3231] = DS3231_BIT_BBSQW,
1247 };
1248 const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
1249
1250 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
1251 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
1252 return -EIO;
1253
1254 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1255 if (!ds1307)
1256 return -ENOMEM;
1257
1258 i2c_set_clientdata(client, ds1307);
1259
1260 ds1307->client = client;
1261 ds1307->type = id->driver_data;
1262
1263 if (!pdata && client->dev.of_node)
1264 ds1307_trickle_of_init(client, chip);
1265 else if (pdata && pdata->trickle_charger_setup)
1266 chip->trickle_charger_setup = pdata->trickle_charger_setup;
1267
1268 if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
1269 dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
1270 DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
1271 chip->trickle_charger_reg);
1272 i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
1273 DS13XX_TRICKLE_CHARGER_MAGIC |
1274 chip->trickle_charger_setup);
1275 }
1276
1277 buf = ds1307->regs;
1278 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
1279 ds1307->read_block_data = ds1307_native_smbus_read_block_data;
1280 ds1307->write_block_data = ds1307_native_smbus_write_block_data;
1281 } else {
1282 ds1307->read_block_data = ds1307_read_block_data;
1283 ds1307->write_block_data = ds1307_write_block_data;
1284 }
1285
1286 #ifdef CONFIG_OF
1287 /*
1288 * For devices with no IRQ directly connected to the SoC, the RTC chip
1289 * can be forced as a wakeup source by stating that explicitly in
1290 * the device's .dts file using the "wakeup-source" boolean property.
1291 * If the "wakeup-source" property is set, don't request an IRQ.
1292 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1293 * if supported by the RTC.
1294 */
1295 if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
1296 ds1307_can_wakeup_device = true;
1297 }
1298 #endif
1299
1300 switch (ds1307->type) {
1301 case ds_1337:
1302 case ds_1339:
1303 case ds_3231:
1304 /* get registers that the "rtc" read below won't read... */
1305 tmp = ds1307->read_block_data(ds1307->client,
1306 DS1337_REG_CONTROL, 2, buf);
1307 if (tmp != 2) {
1308 dev_dbg(&client->dev, "read error %d\n", tmp);
1309 err = -EIO;
1310 goto exit;
1311 }
1312
1313 /* oscillator off? turn it on, so clock can tick. */
1314 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
1315 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
1316
1317 /*
1318 * Using IRQ or defined as wakeup-source?
1319 * Disable the square wave and both alarms.
1320 * For some variants, be sure alarms can trigger when we're
1321 * running on Vbackup (BBSQI/BBSQW)
1322 */
1323 if (chip->alarm && (ds1307->client->irq > 0 ||
1324 ds1307_can_wakeup_device)) {
1325 ds1307->regs[0] |= DS1337_BIT_INTCN
1326 | bbsqi_bitpos[ds1307->type];
1327 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1328
1329 want_irq = true;
1330 }
1331
1332 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
1333 ds1307->regs[0]);
1334
1335 /* oscillator fault? clear flag, and warn */
1336 if (ds1307->regs[1] & DS1337_BIT_OSF) {
1337 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
1338 ds1307->regs[1] & ~DS1337_BIT_OSF);
1339 dev_warn(&client->dev, "SET TIME!\n");
1340 }
1341 break;
1342
1343 case rx_8025:
1344 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1345 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1346 if (tmp != 2) {
1347 dev_dbg(&client->dev, "read error %d\n", tmp);
1348 err = -EIO;
1349 goto exit;
1350 }
1351
1352 /* oscillator off? turn it on, so clock can tick. */
1353 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
1354 ds1307->regs[1] |= RX8025_BIT_XST;
1355 i2c_smbus_write_byte_data(client,
1356 RX8025_REG_CTRL2 << 4 | 0x08,
1357 ds1307->regs[1]);
1358 dev_warn(&client->dev,
1359 "oscillator stop detected - SET TIME!\n");
1360 }
1361
1362 if (ds1307->regs[1] & RX8025_BIT_PON) {
1363 ds1307->regs[1] &= ~RX8025_BIT_PON;
1364 i2c_smbus_write_byte_data(client,
1365 RX8025_REG_CTRL2 << 4 | 0x08,
1366 ds1307->regs[1]);
1367 dev_warn(&client->dev, "power-on detected\n");
1368 }
1369
1370 if (ds1307->regs[1] & RX8025_BIT_VDET) {
1371 ds1307->regs[1] &= ~RX8025_BIT_VDET;
1372 i2c_smbus_write_byte_data(client,
1373 RX8025_REG_CTRL2 << 4 | 0x08,
1374 ds1307->regs[1]);
1375 dev_warn(&client->dev, "voltage drop detected\n");
1376 }
1377
1378 /* make sure we are running in 24hour mode */
1379 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
1380 u8 hour;
1381
1382 /* switch to 24 hour mode */
1383 i2c_smbus_write_byte_data(client,
1384 RX8025_REG_CTRL1 << 4 | 0x08,
1385 ds1307->regs[0] |
1386 RX8025_BIT_2412);
1387
1388 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1389 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1390 if (tmp != 2) {
1391 dev_dbg(&client->dev, "read error %d\n", tmp);
1392 err = -EIO;
1393 goto exit;
1394 }
1395
1396 /* correct hour */
1397 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1398 if (hour == 12)
1399 hour = 0;
1400 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1401 hour += 12;
1402
1403 i2c_smbus_write_byte_data(client,
1404 DS1307_REG_HOUR << 4 | 0x08,
1405 hour);
1406 }
1407 break;
1408 case ds_1388:
1409 ds1307->offset = 1; /* Seconds starts at 1 */
1410 break;
1411 case mcp794xx:
1412 rtc_ops = &mcp794xx_rtc_ops;
1413 if (ds1307->client->irq > 0 && chip->alarm) {
1414 irq_handler = mcp794xx_irq;
1415 want_irq = true;
1416 }
1417 break;
1418 default:
1419 break;
1420 }
1421
1422 read_rtc:
1423 /* read RTC registers */
1424 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1425 if (tmp != 8) {
1426 dev_dbg(&client->dev, "read error %d\n", tmp);
1427 err = -EIO;
1428 goto exit;
1429 }
1430
1431 /*
1432 * minimal sanity checking; some chips (like DS1340) don't
1433 * specify the extra bits as must-be-zero, but there are
1434 * still a few values that are clearly out-of-range.
1435 */
1436 tmp = ds1307->regs[DS1307_REG_SECS];
1437 switch (ds1307->type) {
1438 case ds_1307:
1439 case m41t00:
1440 /* clock halted? turn it on, so clock can tick. */
1441 if (tmp & DS1307_BIT_CH) {
1442 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1443 dev_warn(&client->dev, "SET TIME!\n");
1444 goto read_rtc;
1445 }
1446 break;
1447 case ds_1338:
1448 /* clock halted? turn it on, so clock can tick. */
1449 if (tmp & DS1307_BIT_CH)
1450 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1451
1452 /* oscillator fault? clear flag, and warn */
1453 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1454 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1455 ds1307->regs[DS1307_REG_CONTROL]
1456 & ~DS1338_BIT_OSF);
1457 dev_warn(&client->dev, "SET TIME!\n");
1458 goto read_rtc;
1459 }
1460 break;
1461 case ds_1340:
1462 /* clock halted? turn it on, so clock can tick. */
1463 if (tmp & DS1340_BIT_nEOSC)
1464 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1465
1466 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1467 if (tmp < 0) {
1468 dev_dbg(&client->dev, "read error %d\n", tmp);
1469 err = -EIO;
1470 goto exit;
1471 }
1472
1473 /* oscillator fault? clear flag, and warn */
1474 if (tmp & DS1340_BIT_OSF) {
1475 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1476 dev_warn(&client->dev, "SET TIME!\n");
1477 }
1478 break;
1479 case mcp794xx:
1480 /* make sure that the backup battery is enabled */
1481 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1482 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1483 ds1307->regs[DS1307_REG_WDAY]
1484 | MCP794XX_BIT_VBATEN);
1485 }
1486
1487 /* clock halted? turn it on, so clock can tick. */
1488 if (!(tmp & MCP794XX_BIT_ST)) {
1489 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1490 MCP794XX_BIT_ST);
1491 dev_warn(&client->dev, "SET TIME!\n");
1492 goto read_rtc;
1493 }
1494
1495 break;
1496 default:
1497 break;
1498 }
1499
1500 tmp = ds1307->regs[DS1307_REG_HOUR];
1501 switch (ds1307->type) {
1502 case ds_1340:
1503 case m41t00:
1504 /*
1505 * NOTE: ignores century bits; fix before deploying
1506 * systems that will run through year 2100.
1507 */
1508 break;
1509 case rx_8025:
1510 break;
1511 default:
1512 if (!(tmp & DS1307_BIT_12HR))
1513 break;
1514
1515 /*
1516 * Be sure we're in 24 hour mode. Multi-master systems
1517 * take note...
1518 */
1519 tmp = bcd2bin(tmp & 0x1f);
1520 if (tmp == 12)
1521 tmp = 0;
1522 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1523 tmp += 12;
1524 i2c_smbus_write_byte_data(client,
1525 ds1307->offset + DS1307_REG_HOUR,
1526 bin2bcd(tmp));
1527 }
1528
1529 if (want_irq) {
1530 device_set_wakeup_capable(&client->dev, true);
1531 set_bit(HAS_ALARM, &ds1307->flags);
1532 }
1533 ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1534 rtc_ops, THIS_MODULE);
1535 if (IS_ERR(ds1307->rtc)) {
1536 return PTR_ERR(ds1307->rtc);
1537 }
1538
1539 if (ds1307_can_wakeup_device && ds1307->client->irq <= 0) {
1540 /* Disable request for an IRQ */
1541 want_irq = false;
1542 dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
1543 /* We cannot support UIE mode if we do not have an IRQ line */
1544 ds1307->rtc->uie_unsupported = 1;
1545 }
1546
1547 if (want_irq) {
1548 err = devm_request_threaded_irq(&client->dev,
1549 client->irq, NULL, irq_handler,
1550 IRQF_SHARED | IRQF_ONESHOT,
1551 ds1307->rtc->name, client);
1552 if (err) {
1553 client->irq = 0;
1554 device_set_wakeup_capable(&client->dev, false);
1555 clear_bit(HAS_ALARM, &ds1307->flags);
1556 dev_err(&client->dev, "unable to request IRQ!\n");
1557 } else
1558 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
1559 }
1560
1561 if (chip->nvram_size) {
1562
1563 ds1307->nvram = devm_kzalloc(&client->dev,
1564 sizeof(struct bin_attribute),
1565 GFP_KERNEL);
1566 if (!ds1307->nvram) {
1567 dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1568 } else {
1569
1570 ds1307->nvram->attr.name = "nvram";
1571 ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1572
1573 sysfs_bin_attr_init(ds1307->nvram);
1574
1575 ds1307->nvram->read = ds1307_nvram_read;
1576 ds1307->nvram->write = ds1307_nvram_write;
1577 ds1307->nvram->size = chip->nvram_size;
1578 ds1307->nvram_offset = chip->nvram_offset;
1579
1580 err = sysfs_create_bin_file(&client->dev.kobj,
1581 ds1307->nvram);
1582 if (err) {
1583 dev_err(&client->dev,
1584 "unable to create sysfs file: %s\n",
1585 ds1307->nvram->attr.name);
1586 } else {
1587 set_bit(HAS_NVRAM, &ds1307->flags);
1588 dev_info(&client->dev, "%zu bytes nvram\n",
1589 ds1307->nvram->size);
1590 }
1591 }
1592 }
1593
1594 ds1307_hwmon_register(ds1307);
1595 ds1307_clks_register(ds1307);
1596
1597 return 0;
1598
1599 exit:
1600 return err;
1601 }
1602
1603 static int ds1307_remove(struct i2c_client *client)
1604 {
1605 struct ds1307 *ds1307 = i2c_get_clientdata(client);
1606
1607 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1608 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1609
1610 return 0;
1611 }
1612
1613 static struct i2c_driver ds1307_driver = {
1614 .driver = {
1615 .name = "rtc-ds1307",
1616 },
1617 .probe = ds1307_probe,
1618 .remove = ds1307_remove,
1619 .id_table = ds1307_id,
1620 };
1621
1622 module_i2c_driver(ds1307_driver);
1623
1624 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1625 MODULE_LICENSE("GPL");
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