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[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/acpi.h>
15 #include <linux/bcd.h>
16 #include <linux/i2c.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/rtc/ds1307.h>
20 #include <linux/rtc.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/hwmon.h>
24 #include <linux/hwmon-sysfs.h>
25 #include <linux/clk-provider.h>
26
27 /*
28 * We can't determine type by probing, but if we expect pre-Linux code
29 * to have set the chip up as a clock (turning on the oscillator and
30 * setting the date and time), Linux can ignore the non-clock features.
31 * That's a natural job for a factory or repair bench.
32 */
33 enum ds_type {
34 ds_1307,
35 ds_1337,
36 ds_1338,
37 ds_1339,
38 ds_1340,
39 ds_1388,
40 ds_3231,
41 m41t00,
42 mcp794xx,
43 rx_8025,
44 last_ds_type /* always last */
45 /* rs5c372 too? different address... */
46 };
47
48
49 /* RTC registers don't differ much, except for the century flag */
50 #define DS1307_REG_SECS 0x00 /* 00-59 */
51 # define DS1307_BIT_CH 0x80
52 # define DS1340_BIT_nEOSC 0x80
53 # define MCP794XX_BIT_ST 0x80
54 #define DS1307_REG_MIN 0x01 /* 00-59 */
55 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
56 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
57 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
58 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
59 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
60 #define DS1307_REG_WDAY 0x03 /* 01-07 */
61 # define MCP794XX_BIT_VBATEN 0x08
62 #define DS1307_REG_MDAY 0x04 /* 01-31 */
63 #define DS1307_REG_MONTH 0x05 /* 01-12 */
64 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
65 #define DS1307_REG_YEAR 0x06 /* 00-99 */
66
67 /*
68 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
69 * start at 7, and they differ a LOT. Only control and status matter for
70 * basic RTC date and time functionality; be careful using them.
71 */
72 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
73 # define DS1307_BIT_OUT 0x80
74 # define DS1338_BIT_OSF 0x20
75 # define DS1307_BIT_SQWE 0x10
76 # define DS1307_BIT_RS1 0x02
77 # define DS1307_BIT_RS0 0x01
78 #define DS1337_REG_CONTROL 0x0e
79 # define DS1337_BIT_nEOSC 0x80
80 # define DS1339_BIT_BBSQI 0x20
81 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
82 # define DS1337_BIT_RS2 0x10
83 # define DS1337_BIT_RS1 0x08
84 # define DS1337_BIT_INTCN 0x04
85 # define DS1337_BIT_A2IE 0x02
86 # define DS1337_BIT_A1IE 0x01
87 #define DS1340_REG_CONTROL 0x07
88 # define DS1340_BIT_OUT 0x80
89 # define DS1340_BIT_FT 0x40
90 # define DS1340_BIT_CALIB_SIGN 0x20
91 # define DS1340_M_CALIBRATION 0x1f
92 #define DS1340_REG_FLAG 0x09
93 # define DS1340_BIT_OSF 0x80
94 #define DS1337_REG_STATUS 0x0f
95 # define DS1337_BIT_OSF 0x80
96 # define DS3231_BIT_EN32KHZ 0x08
97 # define DS1337_BIT_A2I 0x02
98 # define DS1337_BIT_A1I 0x01
99 #define DS1339_REG_ALARM1_SECS 0x07
100
101 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
102
103 #define RX8025_REG_CTRL1 0x0e
104 # define RX8025_BIT_2412 0x20
105 #define RX8025_REG_CTRL2 0x0f
106 # define RX8025_BIT_PON 0x10
107 # define RX8025_BIT_VDET 0x40
108 # define RX8025_BIT_XST 0x20
109
110
111 struct ds1307 {
112 u8 offset; /* register's offset */
113 u8 regs[11];
114 u16 nvram_offset;
115 struct bin_attribute *nvram;
116 enum ds_type type;
117 unsigned long flags;
118 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
119 #define HAS_ALARM 1 /* bit 1 == irq claimed */
120 struct i2c_client *client;
121 struct rtc_device *rtc;
122 s32 (*read_block_data)(const struct i2c_client *client, u8 command,
123 u8 length, u8 *values);
124 s32 (*write_block_data)(const struct i2c_client *client, u8 command,
125 u8 length, const u8 *values);
126 #ifdef CONFIG_COMMON_CLK
127 struct clk_hw clks[2];
128 #endif
129 };
130
131 struct chip_desc {
132 unsigned alarm:1;
133 u16 nvram_offset;
134 u16 nvram_size;
135 u16 trickle_charger_reg;
136 u8 trickle_charger_setup;
137 u8 (*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
138 };
139
140 static u8 do_trickle_setup_ds1339(struct i2c_client *,
141 uint32_t ohms, bool diode);
142
143 static struct chip_desc chips[last_ds_type] = {
144 [ds_1307] = {
145 .nvram_offset = 8,
146 .nvram_size = 56,
147 },
148 [ds_1337] = {
149 .alarm = 1,
150 },
151 [ds_1338] = {
152 .nvram_offset = 8,
153 .nvram_size = 56,
154 },
155 [ds_1339] = {
156 .alarm = 1,
157 .trickle_charger_reg = 0x10,
158 .do_trickle_setup = &do_trickle_setup_ds1339,
159 },
160 [ds_1340] = {
161 .trickle_charger_reg = 0x08,
162 },
163 [ds_1388] = {
164 .trickle_charger_reg = 0x0a,
165 },
166 [ds_3231] = {
167 .alarm = 1,
168 },
169 [mcp794xx] = {
170 .alarm = 1,
171 /* this is battery backed SRAM */
172 .nvram_offset = 0x20,
173 .nvram_size = 0x40,
174 },
175 };
176
177 static const struct i2c_device_id ds1307_id[] = {
178 { "ds1307", ds_1307 },
179 { "ds1337", ds_1337 },
180 { "ds1338", ds_1338 },
181 { "ds1339", ds_1339 },
182 { "ds1388", ds_1388 },
183 { "ds1340", ds_1340 },
184 { "ds3231", ds_3231 },
185 { "m41t00", m41t00 },
186 { "mcp7940x", mcp794xx },
187 { "mcp7941x", mcp794xx },
188 { "pt7c4338", ds_1307 },
189 { "rx8025", rx_8025 },
190 { "isl12057", ds_1337 },
191 { }
192 };
193 MODULE_DEVICE_TABLE(i2c, ds1307_id);
194
195 #ifdef CONFIG_ACPI
196 static const struct acpi_device_id ds1307_acpi_ids[] = {
197 { .id = "DS1307", .driver_data = ds_1307 },
198 { .id = "DS1337", .driver_data = ds_1337 },
199 { .id = "DS1338", .driver_data = ds_1338 },
200 { .id = "DS1339", .driver_data = ds_1339 },
201 { .id = "DS1388", .driver_data = ds_1388 },
202 { .id = "DS1340", .driver_data = ds_1340 },
203 { .id = "DS3231", .driver_data = ds_3231 },
204 { .id = "M41T00", .driver_data = m41t00 },
205 { .id = "MCP7940X", .driver_data = mcp794xx },
206 { .id = "MCP7941X", .driver_data = mcp794xx },
207 { .id = "PT7C4338", .driver_data = ds_1307 },
208 { .id = "RX8025", .driver_data = rx_8025 },
209 { .id = "ISL12057", .driver_data = ds_1337 },
210 { }
211 };
212 MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
213 #endif
214
215 /*----------------------------------------------------------------------*/
216
217 #define BLOCK_DATA_MAX_TRIES 10
218
219 static s32 ds1307_read_block_data_once(const struct i2c_client *client,
220 u8 command, u8 length, u8 *values)
221 {
222 s32 i, data;
223
224 for (i = 0; i < length; i++) {
225 data = i2c_smbus_read_byte_data(client, command + i);
226 if (data < 0)
227 return data;
228 values[i] = data;
229 }
230 return i;
231 }
232
233 static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
234 u8 length, u8 *values)
235 {
236 u8 oldvalues[255];
237 s32 ret;
238 int tries = 0;
239
240 dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
241 ret = ds1307_read_block_data_once(client, command, length, values);
242 if (ret < 0)
243 return ret;
244 do {
245 if (++tries > BLOCK_DATA_MAX_TRIES) {
246 dev_err(&client->dev,
247 "ds1307_read_block_data failed\n");
248 return -EIO;
249 }
250 memcpy(oldvalues, values, length);
251 ret = ds1307_read_block_data_once(client, command, length,
252 values);
253 if (ret < 0)
254 return ret;
255 } while (memcmp(oldvalues, values, length));
256 return length;
257 }
258
259 static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
260 u8 length, const u8 *values)
261 {
262 u8 currvalues[255];
263 int tries = 0;
264
265 dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
266 do {
267 s32 i, ret;
268
269 if (++tries > BLOCK_DATA_MAX_TRIES) {
270 dev_err(&client->dev,
271 "ds1307_write_block_data failed\n");
272 return -EIO;
273 }
274 for (i = 0; i < length; i++) {
275 ret = i2c_smbus_write_byte_data(client, command + i,
276 values[i]);
277 if (ret < 0)
278 return ret;
279 }
280 ret = ds1307_read_block_data_once(client, command, length,
281 currvalues);
282 if (ret < 0)
283 return ret;
284 } while (memcmp(currvalues, values, length));
285 return length;
286 }
287
288 /*----------------------------------------------------------------------*/
289
290 /* These RTC devices are not designed to be connected to a SMbus adapter.
291 SMbus limits block operations length to 32 bytes, whereas it's not
292 limited on I2C buses. As a result, accesses may exceed 32 bytes;
293 in that case, split them into smaller blocks */
294
295 static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
296 u8 command, u8 length, const u8 *values)
297 {
298 u8 suboffset = 0;
299
300 if (length <= I2C_SMBUS_BLOCK_MAX) {
301 s32 retval = i2c_smbus_write_i2c_block_data(client,
302 command, length, values);
303 if (retval < 0)
304 return retval;
305 return length;
306 }
307
308 while (suboffset < length) {
309 s32 retval = i2c_smbus_write_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 static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
322 u8 command, u8 length, u8 *values)
323 {
324 u8 suboffset = 0;
325
326 if (length <= I2C_SMBUS_BLOCK_MAX)
327 return i2c_smbus_read_i2c_block_data(client,
328 command, length, values);
329
330 while (suboffset < length) {
331 s32 retval = i2c_smbus_read_i2c_block_data(client,
332 command + suboffset,
333 min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
334 values + suboffset);
335 if (retval < 0)
336 return retval;
337
338 suboffset += I2C_SMBUS_BLOCK_MAX;
339 }
340 return length;
341 }
342
343 /*----------------------------------------------------------------------*/
344
345 /*
346 * The ds1337 and ds1339 both have two alarms, but we only use the first
347 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
348 * signal; ds1339 chips have only one alarm signal.
349 */
350 static irqreturn_t ds1307_irq(int irq, void *dev_id)
351 {
352 struct i2c_client *client = dev_id;
353 struct ds1307 *ds1307 = i2c_get_clientdata(client);
354 struct mutex *lock = &ds1307->rtc->ops_lock;
355 int stat, control;
356
357 mutex_lock(lock);
358 stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
359 if (stat < 0)
360 goto out;
361
362 if (stat & DS1337_BIT_A1I) {
363 stat &= ~DS1337_BIT_A1I;
364 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
365
366 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
367 if (control < 0)
368 goto out;
369
370 control &= ~DS1337_BIT_A1IE;
371 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
372
373 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
374 }
375
376 out:
377 mutex_unlock(lock);
378
379 return IRQ_HANDLED;
380 }
381
382 /*----------------------------------------------------------------------*/
383
384 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
385 {
386 struct ds1307 *ds1307 = dev_get_drvdata(dev);
387 int tmp;
388
389 /* read the RTC date and time registers all at once */
390 tmp = ds1307->read_block_data(ds1307->client,
391 ds1307->offset, 7, ds1307->regs);
392 if (tmp != 7) {
393 dev_err(dev, "%s error %d\n", "read", tmp);
394 return -EIO;
395 }
396
397 dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
398
399 t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
400 t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
401 tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
402 t->tm_hour = bcd2bin(tmp);
403 t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
404 t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
405 tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
406 t->tm_mon = bcd2bin(tmp) - 1;
407 t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
408
409 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
410 switch (ds1307->type) {
411 case ds_1337:
412 case ds_1339:
413 case ds_3231:
414 if (ds1307->regs[DS1307_REG_MONTH] & DS1337_BIT_CENTURY)
415 t->tm_year += 100;
416 break;
417 case ds_1340:
418 if (ds1307->regs[DS1307_REG_HOUR] & DS1340_BIT_CENTURY)
419 t->tm_year += 100;
420 break;
421 default:
422 break;
423 }
424 #endif
425
426 dev_dbg(dev, "%s secs=%d, mins=%d, "
427 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
428 "read", t->tm_sec, t->tm_min,
429 t->tm_hour, t->tm_mday,
430 t->tm_mon, t->tm_year, t->tm_wday);
431
432 /* initial clock setting can be undefined */
433 return rtc_valid_tm(t);
434 }
435
436 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
437 {
438 struct ds1307 *ds1307 = dev_get_drvdata(dev);
439 int result;
440 int tmp;
441 u8 *buf = ds1307->regs;
442
443 dev_dbg(dev, "%s secs=%d, mins=%d, "
444 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
445 "write", t->tm_sec, t->tm_min,
446 t->tm_hour, t->tm_mday,
447 t->tm_mon, t->tm_year, t->tm_wday);
448
449 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
450 if (t->tm_year < 100)
451 return -EINVAL;
452
453 switch (ds1307->type) {
454 case ds_1337:
455 case ds_1339:
456 case ds_3231:
457 case ds_1340:
458 if (t->tm_year > 299)
459 return -EINVAL;
460 default:
461 if (t->tm_year > 199)
462 return -EINVAL;
463 break;
464 }
465 #else
466 if (t->tm_year < 100 || t->tm_year > 199)
467 return -EINVAL;
468 #endif
469
470 buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
471 buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
472 buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
473 buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
474 buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
475 buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
476
477 /* assume 20YY not 19YY */
478 tmp = t->tm_year - 100;
479 buf[DS1307_REG_YEAR] = bin2bcd(tmp);
480
481 switch (ds1307->type) {
482 case ds_1337:
483 case ds_1339:
484 case ds_3231:
485 if (t->tm_year > 199)
486 buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
487 break;
488 case ds_1340:
489 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN;
490 if (t->tm_year > 199)
491 buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY;
492 break;
493 case mcp794xx:
494 /*
495 * these bits were cleared when preparing the date/time
496 * values and need to be set again before writing the
497 * buffer out to the device.
498 */
499 buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
500 buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
501 break;
502 default:
503 break;
504 }
505
506 dev_dbg(dev, "%s: %7ph\n", "write", buf);
507
508 result = ds1307->write_block_data(ds1307->client,
509 ds1307->offset, 7, buf);
510 if (result < 0) {
511 dev_err(dev, "%s error %d\n", "write", result);
512 return result;
513 }
514 return 0;
515 }
516
517 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
518 {
519 struct i2c_client *client = to_i2c_client(dev);
520 struct ds1307 *ds1307 = i2c_get_clientdata(client);
521 int ret;
522
523 if (!test_bit(HAS_ALARM, &ds1307->flags))
524 return -EINVAL;
525
526 /* read all ALARM1, ALARM2, and status registers at once */
527 ret = ds1307->read_block_data(client,
528 DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
529 if (ret != 9) {
530 dev_err(dev, "%s error %d\n", "alarm read", ret);
531 return -EIO;
532 }
533
534 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
535 &ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
536
537 /*
538 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
539 * and that all four fields are checked matches
540 */
541 t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
542 t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
543 t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
544 t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
545
546 /* ... and status */
547 t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
548 t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
549
550 dev_dbg(dev, "%s secs=%d, mins=%d, "
551 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
552 "alarm read", t->time.tm_sec, t->time.tm_min,
553 t->time.tm_hour, t->time.tm_mday,
554 t->enabled, t->pending);
555
556 return 0;
557 }
558
559 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
560 {
561 struct i2c_client *client = to_i2c_client(dev);
562 struct ds1307 *ds1307 = i2c_get_clientdata(client);
563 unsigned char *buf = ds1307->regs;
564 u8 control, status;
565 int ret;
566
567 if (!test_bit(HAS_ALARM, &ds1307->flags))
568 return -EINVAL;
569
570 dev_dbg(dev, "%s secs=%d, mins=%d, "
571 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
572 "alarm set", t->time.tm_sec, t->time.tm_min,
573 t->time.tm_hour, t->time.tm_mday,
574 t->enabled, t->pending);
575
576 /* read current status of both alarms and the chip */
577 ret = ds1307->read_block_data(client,
578 DS1339_REG_ALARM1_SECS, 9, buf);
579 if (ret != 9) {
580 dev_err(dev, "%s error %d\n", "alarm write", ret);
581 return -EIO;
582 }
583 control = ds1307->regs[7];
584 status = ds1307->regs[8];
585
586 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
587 &ds1307->regs[0], &ds1307->regs[4], control, status);
588
589 /* set ALARM1, using 24 hour and day-of-month modes */
590 buf[0] = bin2bcd(t->time.tm_sec);
591 buf[1] = bin2bcd(t->time.tm_min);
592 buf[2] = bin2bcd(t->time.tm_hour);
593 buf[3] = bin2bcd(t->time.tm_mday);
594
595 /* set ALARM2 to non-garbage */
596 buf[4] = 0;
597 buf[5] = 0;
598 buf[6] = 0;
599
600 /* disable alarms */
601 buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
602 buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
603
604 ret = ds1307->write_block_data(client,
605 DS1339_REG_ALARM1_SECS, 9, buf);
606 if (ret < 0) {
607 dev_err(dev, "can't set alarm time\n");
608 return ret;
609 }
610
611 /* optionally enable ALARM1 */
612 if (t->enabled) {
613 dev_dbg(dev, "alarm IRQ armed\n");
614 buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
615 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, buf[7]);
616 }
617
618 return 0;
619 }
620
621 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
622 {
623 struct i2c_client *client = to_i2c_client(dev);
624 struct ds1307 *ds1307 = i2c_get_clientdata(client);
625 int ret;
626
627 if (!test_bit(HAS_ALARM, &ds1307->flags))
628 return -ENOTTY;
629
630 ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
631 if (ret < 0)
632 return ret;
633
634 if (enabled)
635 ret |= DS1337_BIT_A1IE;
636 else
637 ret &= ~DS1337_BIT_A1IE;
638
639 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
640 if (ret < 0)
641 return ret;
642
643 return 0;
644 }
645
646 static const struct rtc_class_ops ds13xx_rtc_ops = {
647 .read_time = ds1307_get_time,
648 .set_time = ds1307_set_time,
649 .read_alarm = ds1337_read_alarm,
650 .set_alarm = ds1337_set_alarm,
651 .alarm_irq_enable = ds1307_alarm_irq_enable,
652 };
653
654 /*----------------------------------------------------------------------*/
655
656 /*
657 * Alarm support for mcp794xx devices.
658 */
659
660 #define MCP794XX_REG_WEEKDAY 0x3
661 #define MCP794XX_REG_WEEKDAY_WDAY_MASK 0x7
662 #define MCP794XX_REG_CONTROL 0x07
663 # define MCP794XX_BIT_ALM0_EN 0x10
664 # define MCP794XX_BIT_ALM1_EN 0x20
665 #define MCP794XX_REG_ALARM0_BASE 0x0a
666 #define MCP794XX_REG_ALARM0_CTRL 0x0d
667 #define MCP794XX_REG_ALARM1_BASE 0x11
668 #define MCP794XX_REG_ALARM1_CTRL 0x14
669 # define MCP794XX_BIT_ALMX_IF (1 << 3)
670 # define MCP794XX_BIT_ALMX_C0 (1 << 4)
671 # define MCP794XX_BIT_ALMX_C1 (1 << 5)
672 # define MCP794XX_BIT_ALMX_C2 (1 << 6)
673 # define MCP794XX_BIT_ALMX_POL (1 << 7)
674 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
675 MCP794XX_BIT_ALMX_C1 | \
676 MCP794XX_BIT_ALMX_C2)
677
678 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
679 {
680 struct i2c_client *client = dev_id;
681 struct ds1307 *ds1307 = i2c_get_clientdata(client);
682 struct mutex *lock = &ds1307->rtc->ops_lock;
683 int reg, ret;
684
685 mutex_lock(lock);
686
687 /* Check and clear alarm 0 interrupt flag. */
688 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
689 if (reg < 0)
690 goto out;
691 if (!(reg & MCP794XX_BIT_ALMX_IF))
692 goto out;
693 reg &= ~MCP794XX_BIT_ALMX_IF;
694 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
695 if (ret < 0)
696 goto out;
697
698 /* Disable alarm 0. */
699 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
700 if (reg < 0)
701 goto out;
702 reg &= ~MCP794XX_BIT_ALM0_EN;
703 ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
704 if (ret < 0)
705 goto out;
706
707 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
708
709 out:
710 mutex_unlock(lock);
711
712 return IRQ_HANDLED;
713 }
714
715 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
716 {
717 struct i2c_client *client = to_i2c_client(dev);
718 struct ds1307 *ds1307 = i2c_get_clientdata(client);
719 u8 *regs = ds1307->regs;
720 int ret;
721
722 if (!test_bit(HAS_ALARM, &ds1307->flags))
723 return -EINVAL;
724
725 /* Read control and alarm 0 registers. */
726 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
727 if (ret < 0)
728 return ret;
729
730 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
731
732 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
733 t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
734 t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
735 t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
736 t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
737 t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
738 t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
739 t->time.tm_year = -1;
740 t->time.tm_yday = -1;
741 t->time.tm_isdst = -1;
742
743 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
744 "enabled=%d polarity=%d irq=%d match=%d\n", __func__,
745 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
746 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
747 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
748 !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
749 (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
750
751 return 0;
752 }
753
754 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
755 {
756 struct i2c_client *client = to_i2c_client(dev);
757 struct ds1307 *ds1307 = i2c_get_clientdata(client);
758 unsigned char *regs = ds1307->regs;
759 int ret;
760
761 if (!test_bit(HAS_ALARM, &ds1307->flags))
762 return -EINVAL;
763
764 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
765 "enabled=%d pending=%d\n", __func__,
766 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
767 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
768 t->enabled, t->pending);
769
770 /* Read control and alarm 0 registers. */
771 ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
772 if (ret < 0)
773 return ret;
774
775 /* Set alarm 0, using 24-hour and day-of-month modes. */
776 regs[3] = bin2bcd(t->time.tm_sec);
777 regs[4] = bin2bcd(t->time.tm_min);
778 regs[5] = bin2bcd(t->time.tm_hour);
779 regs[6] = bin2bcd(t->time.tm_wday + 1);
780 regs[7] = bin2bcd(t->time.tm_mday);
781 regs[8] = bin2bcd(t->time.tm_mon + 1);
782
783 /* Clear the alarm 0 interrupt flag. */
784 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
785 /* Set alarm match: second, minute, hour, day, date, month. */
786 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
787 /* Disable interrupt. We will not enable until completely programmed */
788 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
789
790 ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
791 if (ret < 0)
792 return ret;
793
794 if (!t->enabled)
795 return 0;
796 regs[0] |= MCP794XX_BIT_ALM0_EN;
797 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
798 }
799
800 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
801 {
802 struct i2c_client *client = to_i2c_client(dev);
803 struct ds1307 *ds1307 = i2c_get_clientdata(client);
804 int reg;
805
806 if (!test_bit(HAS_ALARM, &ds1307->flags))
807 return -EINVAL;
808
809 reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
810 if (reg < 0)
811 return reg;
812
813 if (enabled)
814 reg |= MCP794XX_BIT_ALM0_EN;
815 else
816 reg &= ~MCP794XX_BIT_ALM0_EN;
817
818 return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
819 }
820
821 static const struct rtc_class_ops mcp794xx_rtc_ops = {
822 .read_time = ds1307_get_time,
823 .set_time = ds1307_set_time,
824 .read_alarm = mcp794xx_read_alarm,
825 .set_alarm = mcp794xx_set_alarm,
826 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
827 };
828
829 /*----------------------------------------------------------------------*/
830
831 static ssize_t
832 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
833 struct bin_attribute *attr,
834 char *buf, loff_t off, size_t count)
835 {
836 struct i2c_client *client;
837 struct ds1307 *ds1307;
838 int result;
839
840 client = kobj_to_i2c_client(kobj);
841 ds1307 = i2c_get_clientdata(client);
842
843 result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
844 count, buf);
845 if (result < 0)
846 dev_err(&client->dev, "%s error %d\n", "nvram read", result);
847 return result;
848 }
849
850 static ssize_t
851 ds1307_nvram_write(struct file *filp, struct kobject *kobj,
852 struct bin_attribute *attr,
853 char *buf, loff_t off, size_t count)
854 {
855 struct i2c_client *client;
856 struct ds1307 *ds1307;
857 int result;
858
859 client = kobj_to_i2c_client(kobj);
860 ds1307 = i2c_get_clientdata(client);
861
862 result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
863 count, buf);
864 if (result < 0) {
865 dev_err(&client->dev, "%s error %d\n", "nvram write", result);
866 return result;
867 }
868 return count;
869 }
870
871
872 /*----------------------------------------------------------------------*/
873
874 static u8 do_trickle_setup_ds1339(struct i2c_client *client,
875 uint32_t ohms, bool diode)
876 {
877 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
878 DS1307_TRICKLE_CHARGER_NO_DIODE;
879
880 switch (ohms) {
881 case 250:
882 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
883 break;
884 case 2000:
885 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
886 break;
887 case 4000:
888 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
889 break;
890 default:
891 dev_warn(&client->dev,
892 "Unsupported ohm value %u in dt\n", ohms);
893 return 0;
894 }
895 return setup;
896 }
897
898 static void ds1307_trickle_init(struct i2c_client *client,
899 struct chip_desc *chip)
900 {
901 uint32_t ohms = 0;
902 bool diode = true;
903
904 if (!chip->do_trickle_setup)
905 goto out;
906 if (device_property_read_u32(&client->dev, "trickle-resistor-ohms", &ohms))
907 goto out;
908 if (device_property_read_bool(&client->dev, "trickle-diode-disable"))
909 diode = false;
910 chip->trickle_charger_setup = chip->do_trickle_setup(client,
911 ohms, diode);
912 out:
913 return;
914 }
915
916 /*----------------------------------------------------------------------*/
917
918 #ifdef CONFIG_RTC_DRV_DS1307_HWMON
919
920 /*
921 * Temperature sensor support for ds3231 devices.
922 */
923
924 #define DS3231_REG_TEMPERATURE 0x11
925
926 /*
927 * A user-initiated temperature conversion is not started by this function,
928 * so the temperature is updated once every 64 seconds.
929 */
930 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
931 {
932 struct ds1307 *ds1307 = dev_get_drvdata(dev);
933 u8 temp_buf[2];
934 s16 temp;
935 int ret;
936
937 ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE,
938 sizeof(temp_buf), temp_buf);
939 if (ret < 0)
940 return ret;
941 if (ret != sizeof(temp_buf))
942 return -EIO;
943
944 /*
945 * Temperature is represented as a 10-bit code with a resolution of
946 * 0.25 degree celsius and encoded in two's complement format.
947 */
948 temp = (temp_buf[0] << 8) | temp_buf[1];
949 temp >>= 6;
950 *mC = temp * 250;
951
952 return 0;
953 }
954
955 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
956 struct device_attribute *attr, char *buf)
957 {
958 int ret;
959 s32 temp;
960
961 ret = ds3231_hwmon_read_temp(dev, &temp);
962 if (ret)
963 return ret;
964
965 return sprintf(buf, "%d\n", temp);
966 }
967 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp,
968 NULL, 0);
969
970 static struct attribute *ds3231_hwmon_attrs[] = {
971 &sensor_dev_attr_temp1_input.dev_attr.attr,
972 NULL,
973 };
974 ATTRIBUTE_GROUPS(ds3231_hwmon);
975
976 static void ds1307_hwmon_register(struct ds1307 *ds1307)
977 {
978 struct device *dev;
979
980 if (ds1307->type != ds_3231)
981 return;
982
983 dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev,
984 ds1307->client->name,
985 ds1307, ds3231_hwmon_groups);
986 if (IS_ERR(dev)) {
987 dev_warn(&ds1307->client->dev,
988 "unable to register hwmon device %ld\n", PTR_ERR(dev));
989 }
990 }
991
992 #else
993
994 static void ds1307_hwmon_register(struct ds1307 *ds1307)
995 {
996 }
997
998 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
999
1000 /*----------------------------------------------------------------------*/
1001
1002 /*
1003 * Square-wave output support for DS3231
1004 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1005 */
1006 #ifdef CONFIG_COMMON_CLK
1007
1008 enum {
1009 DS3231_CLK_SQW = 0,
1010 DS3231_CLK_32KHZ,
1011 };
1012
1013 #define clk_sqw_to_ds1307(clk) \
1014 container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1015 #define clk_32khz_to_ds1307(clk) \
1016 container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1017
1018 static int ds3231_clk_sqw_rates[] = {
1019 1,
1020 1024,
1021 4096,
1022 8192,
1023 };
1024
1025 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1026 {
1027 struct i2c_client *client = ds1307->client;
1028 struct mutex *lock = &ds1307->rtc->ops_lock;
1029 int control;
1030 int ret;
1031
1032 mutex_lock(lock);
1033
1034 control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
1035 if (control < 0) {
1036 ret = control;
1037 goto out;
1038 }
1039
1040 control &= ~mask;
1041 control |= value;
1042
1043 ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
1044 out:
1045 mutex_unlock(lock);
1046
1047 return ret;
1048 }
1049
1050 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1051 unsigned long parent_rate)
1052 {
1053 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1054 int control;
1055 int rate_sel = 0;
1056
1057 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1058 if (control < 0)
1059 return control;
1060 if (control & DS1337_BIT_RS1)
1061 rate_sel += 1;
1062 if (control & DS1337_BIT_RS2)
1063 rate_sel += 2;
1064
1065 return ds3231_clk_sqw_rates[rate_sel];
1066 }
1067
1068 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1069 unsigned long *prate)
1070 {
1071 int i;
1072
1073 for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1074 if (ds3231_clk_sqw_rates[i] <= rate)
1075 return ds3231_clk_sqw_rates[i];
1076 }
1077
1078 return 0;
1079 }
1080
1081 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1082 unsigned long parent_rate)
1083 {
1084 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1085 int control = 0;
1086 int rate_sel;
1087
1088 for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1089 rate_sel++) {
1090 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1091 break;
1092 }
1093
1094 if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1095 return -EINVAL;
1096
1097 if (rate_sel & 1)
1098 control |= DS1337_BIT_RS1;
1099 if (rate_sel & 2)
1100 control |= DS1337_BIT_RS2;
1101
1102 return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1103 control);
1104 }
1105
1106 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1107 {
1108 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1109
1110 return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1111 }
1112
1113 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1114 {
1115 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1116
1117 ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1118 }
1119
1120 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1121 {
1122 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1123 int control;
1124
1125 control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1126 if (control < 0)
1127 return control;
1128
1129 return !(control & DS1337_BIT_INTCN);
1130 }
1131
1132 static const struct clk_ops ds3231_clk_sqw_ops = {
1133 .prepare = ds3231_clk_sqw_prepare,
1134 .unprepare = ds3231_clk_sqw_unprepare,
1135 .is_prepared = ds3231_clk_sqw_is_prepared,
1136 .recalc_rate = ds3231_clk_sqw_recalc_rate,
1137 .round_rate = ds3231_clk_sqw_round_rate,
1138 .set_rate = ds3231_clk_sqw_set_rate,
1139 };
1140
1141 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1142 unsigned long parent_rate)
1143 {
1144 return 32768;
1145 }
1146
1147 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1148 {
1149 struct i2c_client *client = ds1307->client;
1150 struct mutex *lock = &ds1307->rtc->ops_lock;
1151 int status;
1152 int ret;
1153
1154 mutex_lock(lock);
1155
1156 status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
1157 if (status < 0) {
1158 ret = status;
1159 goto out;
1160 }
1161
1162 if (enable)
1163 status |= DS3231_BIT_EN32KHZ;
1164 else
1165 status &= ~DS3231_BIT_EN32KHZ;
1166
1167 ret = i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, status);
1168 out:
1169 mutex_unlock(lock);
1170
1171 return ret;
1172 }
1173
1174 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1175 {
1176 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1177
1178 return ds3231_clk_32khz_control(ds1307, true);
1179 }
1180
1181 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1182 {
1183 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1184
1185 ds3231_clk_32khz_control(ds1307, false);
1186 }
1187
1188 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1189 {
1190 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1191 int status;
1192
1193 status = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_STATUS);
1194 if (status < 0)
1195 return status;
1196
1197 return !!(status & DS3231_BIT_EN32KHZ);
1198 }
1199
1200 static const struct clk_ops ds3231_clk_32khz_ops = {
1201 .prepare = ds3231_clk_32khz_prepare,
1202 .unprepare = ds3231_clk_32khz_unprepare,
1203 .is_prepared = ds3231_clk_32khz_is_prepared,
1204 .recalc_rate = ds3231_clk_32khz_recalc_rate,
1205 };
1206
1207 static struct clk_init_data ds3231_clks_init[] = {
1208 [DS3231_CLK_SQW] = {
1209 .name = "ds3231_clk_sqw",
1210 .ops = &ds3231_clk_sqw_ops,
1211 },
1212 [DS3231_CLK_32KHZ] = {
1213 .name = "ds3231_clk_32khz",
1214 .ops = &ds3231_clk_32khz_ops,
1215 },
1216 };
1217
1218 static int ds3231_clks_register(struct ds1307 *ds1307)
1219 {
1220 struct i2c_client *client = ds1307->client;
1221 struct device_node *node = client->dev.of_node;
1222 struct clk_onecell_data *onecell;
1223 int i;
1224
1225 onecell = devm_kzalloc(&client->dev, sizeof(*onecell), GFP_KERNEL);
1226 if (!onecell)
1227 return -ENOMEM;
1228
1229 onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1230 onecell->clks = devm_kcalloc(&client->dev, onecell->clk_num,
1231 sizeof(onecell->clks[0]), GFP_KERNEL);
1232 if (!onecell->clks)
1233 return -ENOMEM;
1234
1235 for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1236 struct clk_init_data init = ds3231_clks_init[i];
1237
1238 /*
1239 * Interrupt signal due to alarm conditions and square-wave
1240 * output share same pin, so don't initialize both.
1241 */
1242 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1243 continue;
1244
1245 /* optional override of the clockname */
1246 of_property_read_string_index(node, "clock-output-names", i,
1247 &init.name);
1248 ds1307->clks[i].init = &init;
1249
1250 onecell->clks[i] = devm_clk_register(&client->dev,
1251 &ds1307->clks[i]);
1252 if (IS_ERR(onecell->clks[i]))
1253 return PTR_ERR(onecell->clks[i]);
1254 }
1255
1256 if (!node)
1257 return 0;
1258
1259 of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1260
1261 return 0;
1262 }
1263
1264 static void ds1307_clks_register(struct ds1307 *ds1307)
1265 {
1266 int ret;
1267
1268 if (ds1307->type != ds_3231)
1269 return;
1270
1271 ret = ds3231_clks_register(ds1307);
1272 if (ret) {
1273 dev_warn(&ds1307->client->dev,
1274 "unable to register clock device %d\n", ret);
1275 }
1276 }
1277
1278 #else
1279
1280 static void ds1307_clks_register(struct ds1307 *ds1307)
1281 {
1282 }
1283
1284 #endif /* CONFIG_COMMON_CLK */
1285
1286 static int ds1307_probe(struct i2c_client *client,
1287 const struct i2c_device_id *id)
1288 {
1289 struct ds1307 *ds1307;
1290 int err = -ENODEV;
1291 int tmp, wday;
1292 struct chip_desc *chip;
1293 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
1294 bool want_irq = false;
1295 bool ds1307_can_wakeup_device = false;
1296 unsigned char *buf;
1297 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1298 struct rtc_time tm;
1299 unsigned long timestamp;
1300
1301 irq_handler_t irq_handler = ds1307_irq;
1302
1303 static const int bbsqi_bitpos[] = {
1304 [ds_1337] = 0,
1305 [ds_1339] = DS1339_BIT_BBSQI,
1306 [ds_3231] = DS3231_BIT_BBSQW,
1307 };
1308 const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
1309
1310 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
1311 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
1312 return -EIO;
1313
1314 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1315 if (!ds1307)
1316 return -ENOMEM;
1317
1318 i2c_set_clientdata(client, ds1307);
1319
1320 ds1307->client = client;
1321 if (id) {
1322 chip = &chips[id->driver_data];
1323 ds1307->type = id->driver_data;
1324 } else {
1325 const struct acpi_device_id *acpi_id;
1326
1327 acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1328 &client->dev);
1329 if (!acpi_id)
1330 return -ENODEV;
1331 chip = &chips[acpi_id->driver_data];
1332 ds1307->type = acpi_id->driver_data;
1333 }
1334
1335 if (!pdata)
1336 ds1307_trickle_init(client, chip);
1337 else if (pdata->trickle_charger_setup)
1338 chip->trickle_charger_setup = pdata->trickle_charger_setup;
1339
1340 if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
1341 dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
1342 DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
1343 chip->trickle_charger_reg);
1344 i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
1345 DS13XX_TRICKLE_CHARGER_MAGIC |
1346 chip->trickle_charger_setup);
1347 }
1348
1349 buf = ds1307->regs;
1350 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
1351 ds1307->read_block_data = ds1307_native_smbus_read_block_data;
1352 ds1307->write_block_data = ds1307_native_smbus_write_block_data;
1353 } else {
1354 ds1307->read_block_data = ds1307_read_block_data;
1355 ds1307->write_block_data = ds1307_write_block_data;
1356 }
1357
1358 #ifdef CONFIG_OF
1359 /*
1360 * For devices with no IRQ directly connected to the SoC, the RTC chip
1361 * can be forced as a wakeup source by stating that explicitly in
1362 * the device's .dts file using the "wakeup-source" boolean property.
1363 * If the "wakeup-source" property is set, don't request an IRQ.
1364 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1365 * if supported by the RTC.
1366 */
1367 if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
1368 ds1307_can_wakeup_device = true;
1369 }
1370 /* Intersil ISL12057 DT backward compatibility */
1371 if (of_property_read_bool(client->dev.of_node,
1372 "isil,irq2-can-wakeup-machine")) {
1373 ds1307_can_wakeup_device = true;
1374 }
1375 #endif
1376
1377 switch (ds1307->type) {
1378 case ds_1337:
1379 case ds_1339:
1380 case ds_3231:
1381 /* get registers that the "rtc" read below won't read... */
1382 tmp = ds1307->read_block_data(ds1307->client,
1383 DS1337_REG_CONTROL, 2, buf);
1384 if (tmp != 2) {
1385 dev_dbg(&client->dev, "read error %d\n", tmp);
1386 err = -EIO;
1387 goto exit;
1388 }
1389
1390 /* oscillator off? turn it on, so clock can tick. */
1391 if (ds1307->regs[0] & DS1337_BIT_nEOSC)
1392 ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
1393
1394 /*
1395 * Using IRQ or defined as wakeup-source?
1396 * Disable the square wave and both alarms.
1397 * For some variants, be sure alarms can trigger when we're
1398 * running on Vbackup (BBSQI/BBSQW)
1399 */
1400 if (chip->alarm && (ds1307->client->irq > 0 ||
1401 ds1307_can_wakeup_device)) {
1402 ds1307->regs[0] |= DS1337_BIT_INTCN
1403 | bbsqi_bitpos[ds1307->type];
1404 ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1405
1406 want_irq = true;
1407 }
1408
1409 i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
1410 ds1307->regs[0]);
1411
1412 /* oscillator fault? clear flag, and warn */
1413 if (ds1307->regs[1] & DS1337_BIT_OSF) {
1414 i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
1415 ds1307->regs[1] & ~DS1337_BIT_OSF);
1416 dev_warn(&client->dev, "SET TIME!\n");
1417 }
1418 break;
1419
1420 case rx_8025:
1421 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1422 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1423 if (tmp != 2) {
1424 dev_dbg(&client->dev, "read error %d\n", tmp);
1425 err = -EIO;
1426 goto exit;
1427 }
1428
1429 /* oscillator off? turn it on, so clock can tick. */
1430 if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
1431 ds1307->regs[1] |= RX8025_BIT_XST;
1432 i2c_smbus_write_byte_data(client,
1433 RX8025_REG_CTRL2 << 4 | 0x08,
1434 ds1307->regs[1]);
1435 dev_warn(&client->dev,
1436 "oscillator stop detected - SET TIME!\n");
1437 }
1438
1439 if (ds1307->regs[1] & RX8025_BIT_PON) {
1440 ds1307->regs[1] &= ~RX8025_BIT_PON;
1441 i2c_smbus_write_byte_data(client,
1442 RX8025_REG_CTRL2 << 4 | 0x08,
1443 ds1307->regs[1]);
1444 dev_warn(&client->dev, "power-on detected\n");
1445 }
1446
1447 if (ds1307->regs[1] & RX8025_BIT_VDET) {
1448 ds1307->regs[1] &= ~RX8025_BIT_VDET;
1449 i2c_smbus_write_byte_data(client,
1450 RX8025_REG_CTRL2 << 4 | 0x08,
1451 ds1307->regs[1]);
1452 dev_warn(&client->dev, "voltage drop detected\n");
1453 }
1454
1455 /* make sure we are running in 24hour mode */
1456 if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
1457 u8 hour;
1458
1459 /* switch to 24 hour mode */
1460 i2c_smbus_write_byte_data(client,
1461 RX8025_REG_CTRL1 << 4 | 0x08,
1462 ds1307->regs[0] |
1463 RX8025_BIT_2412);
1464
1465 tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1466 RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1467 if (tmp != 2) {
1468 dev_dbg(&client->dev, "read error %d\n", tmp);
1469 err = -EIO;
1470 goto exit;
1471 }
1472
1473 /* correct hour */
1474 hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1475 if (hour == 12)
1476 hour = 0;
1477 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1478 hour += 12;
1479
1480 i2c_smbus_write_byte_data(client,
1481 DS1307_REG_HOUR << 4 | 0x08,
1482 hour);
1483 }
1484 break;
1485 case ds_1388:
1486 ds1307->offset = 1; /* Seconds starts at 1 */
1487 break;
1488 case mcp794xx:
1489 rtc_ops = &mcp794xx_rtc_ops;
1490 if (ds1307->client->irq > 0 && chip->alarm) {
1491 irq_handler = mcp794xx_irq;
1492 want_irq = true;
1493 }
1494 break;
1495 default:
1496 break;
1497 }
1498
1499 read_rtc:
1500 /* read RTC registers */
1501 tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1502 if (tmp != 8) {
1503 dev_dbg(&client->dev, "read error %d\n", tmp);
1504 err = -EIO;
1505 goto exit;
1506 }
1507
1508 /*
1509 * minimal sanity checking; some chips (like DS1340) don't
1510 * specify the extra bits as must-be-zero, but there are
1511 * still a few values that are clearly out-of-range.
1512 */
1513 tmp = ds1307->regs[DS1307_REG_SECS];
1514 switch (ds1307->type) {
1515 case ds_1307:
1516 case m41t00:
1517 /* clock halted? turn it on, so clock can tick. */
1518 if (tmp & DS1307_BIT_CH) {
1519 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1520 dev_warn(&client->dev, "SET TIME!\n");
1521 goto read_rtc;
1522 }
1523 break;
1524 case ds_1338:
1525 /* clock halted? turn it on, so clock can tick. */
1526 if (tmp & DS1307_BIT_CH)
1527 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1528
1529 /* oscillator fault? clear flag, and warn */
1530 if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1531 i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1532 ds1307->regs[DS1307_REG_CONTROL]
1533 & ~DS1338_BIT_OSF);
1534 dev_warn(&client->dev, "SET TIME!\n");
1535 goto read_rtc;
1536 }
1537 break;
1538 case ds_1340:
1539 /* clock halted? turn it on, so clock can tick. */
1540 if (tmp & DS1340_BIT_nEOSC)
1541 i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1542
1543 tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1544 if (tmp < 0) {
1545 dev_dbg(&client->dev, "read error %d\n", tmp);
1546 err = -EIO;
1547 goto exit;
1548 }
1549
1550 /* oscillator fault? clear flag, and warn */
1551 if (tmp & DS1340_BIT_OSF) {
1552 i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1553 dev_warn(&client->dev, "SET TIME!\n");
1554 }
1555 break;
1556 case mcp794xx:
1557 /* make sure that the backup battery is enabled */
1558 if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1559 i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1560 ds1307->regs[DS1307_REG_WDAY]
1561 | MCP794XX_BIT_VBATEN);
1562 }
1563
1564 /* clock halted? turn it on, so clock can tick. */
1565 if (!(tmp & MCP794XX_BIT_ST)) {
1566 i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1567 MCP794XX_BIT_ST);
1568 dev_warn(&client->dev, "SET TIME!\n");
1569 goto read_rtc;
1570 }
1571
1572 break;
1573 default:
1574 break;
1575 }
1576
1577 tmp = ds1307->regs[DS1307_REG_HOUR];
1578 switch (ds1307->type) {
1579 case ds_1340:
1580 case m41t00:
1581 /*
1582 * NOTE: ignores century bits; fix before deploying
1583 * systems that will run through year 2100.
1584 */
1585 break;
1586 case rx_8025:
1587 break;
1588 default:
1589 if (!(tmp & DS1307_BIT_12HR))
1590 break;
1591
1592 /*
1593 * Be sure we're in 24 hour mode. Multi-master systems
1594 * take note...
1595 */
1596 tmp = bcd2bin(tmp & 0x1f);
1597 if (tmp == 12)
1598 tmp = 0;
1599 if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1600 tmp += 12;
1601 i2c_smbus_write_byte_data(client,
1602 ds1307->offset + DS1307_REG_HOUR,
1603 bin2bcd(tmp));
1604 }
1605
1606 /*
1607 * Some IPs have weekday reset value = 0x1 which might not correct
1608 * hence compute the wday using the current date/month/year values
1609 */
1610 ds1307_get_time(&client->dev, &tm);
1611 wday = tm.tm_wday;
1612 timestamp = rtc_tm_to_time64(&tm);
1613 rtc_time64_to_tm(timestamp, &tm);
1614
1615 /*
1616 * Check if reset wday is different from the computed wday
1617 * If different then set the wday which we computed using
1618 * timestamp
1619 */
1620 if (wday != tm.tm_wday) {
1621 wday = i2c_smbus_read_byte_data(client, MCP794XX_REG_WEEKDAY);
1622 wday = wday & ~MCP794XX_REG_WEEKDAY_WDAY_MASK;
1623 wday = wday | (tm.tm_wday + 1);
1624 i2c_smbus_write_byte_data(client, MCP794XX_REG_WEEKDAY, wday);
1625 }
1626
1627 if (want_irq) {
1628 device_set_wakeup_capable(&client->dev, true);
1629 set_bit(HAS_ALARM, &ds1307->flags);
1630 }
1631 ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1632 rtc_ops, THIS_MODULE);
1633 if (IS_ERR(ds1307->rtc)) {
1634 return PTR_ERR(ds1307->rtc);
1635 }
1636
1637 if (ds1307_can_wakeup_device && ds1307->client->irq <= 0) {
1638 /* Disable request for an IRQ */
1639 want_irq = false;
1640 dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
1641 /* We cannot support UIE mode if we do not have an IRQ line */
1642 ds1307->rtc->uie_unsupported = 1;
1643 }
1644
1645 if (want_irq) {
1646 err = devm_request_threaded_irq(&client->dev,
1647 client->irq, NULL, irq_handler,
1648 IRQF_SHARED | IRQF_ONESHOT,
1649 ds1307->rtc->name, client);
1650 if (err) {
1651 client->irq = 0;
1652 device_set_wakeup_capable(&client->dev, false);
1653 clear_bit(HAS_ALARM, &ds1307->flags);
1654 dev_err(&client->dev, "unable to request IRQ!\n");
1655 } else
1656 dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
1657 }
1658
1659 if (chip->nvram_size) {
1660
1661 ds1307->nvram = devm_kzalloc(&client->dev,
1662 sizeof(struct bin_attribute),
1663 GFP_KERNEL);
1664 if (!ds1307->nvram) {
1665 dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1666 } else {
1667
1668 ds1307->nvram->attr.name = "nvram";
1669 ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1670
1671 sysfs_bin_attr_init(ds1307->nvram);
1672
1673 ds1307->nvram->read = ds1307_nvram_read;
1674 ds1307->nvram->write = ds1307_nvram_write;
1675 ds1307->nvram->size = chip->nvram_size;
1676 ds1307->nvram_offset = chip->nvram_offset;
1677
1678 err = sysfs_create_bin_file(&client->dev.kobj,
1679 ds1307->nvram);
1680 if (err) {
1681 dev_err(&client->dev,
1682 "unable to create sysfs file: %s\n",
1683 ds1307->nvram->attr.name);
1684 } else {
1685 set_bit(HAS_NVRAM, &ds1307->flags);
1686 dev_info(&client->dev, "%zu bytes nvram\n",
1687 ds1307->nvram->size);
1688 }
1689 }
1690 }
1691
1692 ds1307_hwmon_register(ds1307);
1693 ds1307_clks_register(ds1307);
1694
1695 return 0;
1696
1697 exit:
1698 return err;
1699 }
1700
1701 static int ds1307_remove(struct i2c_client *client)
1702 {
1703 struct ds1307 *ds1307 = i2c_get_clientdata(client);
1704
1705 if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1706 sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1707
1708 return 0;
1709 }
1710
1711 static struct i2c_driver ds1307_driver = {
1712 .driver = {
1713 .name = "rtc-ds1307",
1714 .acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
1715 },
1716 .probe = ds1307_probe,
1717 .remove = ds1307_remove,
1718 .id_table = ds1307_id,
1719 };
1720
1721 module_i2c_driver(ds1307_driver);
1722
1723 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1724 MODULE_LICENSE("GPL");
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