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Merge tag 'iio-for-4.20a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23...
[mirror_ubuntu-jammy-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/of_device.h>
20 #include <linux/rtc/ds1307.h>
21 #include <linux/rtc.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/hwmon.h>
25 #include <linux/hwmon-sysfs.h>
26 #include <linux/clk-provider.h>
27 #include <linux/regmap.h>
28
29 /*
30 * We can't determine type by probing, but if we expect pre-Linux code
31 * to have set the chip up as a clock (turning on the oscillator and
32 * setting the date and time), Linux can ignore the non-clock features.
33 * That's a natural job for a factory or repair bench.
34 */
35 enum ds_type {
36 ds_1307,
37 ds_1308,
38 ds_1337,
39 ds_1338,
40 ds_1339,
41 ds_1340,
42 ds_1341,
43 ds_1388,
44 ds_3231,
45 m41t0,
46 m41t00,
47 m41t11,
48 mcp794xx,
49 rx_8025,
50 rx_8130,
51 last_ds_type /* always last */
52 /* rs5c372 too? different address... */
53 };
54
55 /* RTC registers don't differ much, except for the century flag */
56 #define DS1307_REG_SECS 0x00 /* 00-59 */
57 # define DS1307_BIT_CH 0x80
58 # define DS1340_BIT_nEOSC 0x80
59 # define MCP794XX_BIT_ST 0x80
60 #define DS1307_REG_MIN 0x01 /* 00-59 */
61 # define M41T0_BIT_OF 0x80
62 #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
63 # define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
64 # define DS1307_BIT_PM 0x20 /* in REG_HOUR */
65 # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
66 # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
67 #define DS1307_REG_WDAY 0x03 /* 01-07 */
68 # define MCP794XX_BIT_VBATEN 0x08
69 #define DS1307_REG_MDAY 0x04 /* 01-31 */
70 #define DS1307_REG_MONTH 0x05 /* 01-12 */
71 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
72 #define DS1307_REG_YEAR 0x06 /* 00-99 */
73
74 /*
75 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
76 * start at 7, and they differ a LOT. Only control and status matter for
77 * basic RTC date and time functionality; be careful using them.
78 */
79 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
80 # define DS1307_BIT_OUT 0x80
81 # define DS1338_BIT_OSF 0x20
82 # define DS1307_BIT_SQWE 0x10
83 # define DS1307_BIT_RS1 0x02
84 # define DS1307_BIT_RS0 0x01
85 #define DS1337_REG_CONTROL 0x0e
86 # define DS1337_BIT_nEOSC 0x80
87 # define DS1339_BIT_BBSQI 0x20
88 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
89 # define DS1337_BIT_RS2 0x10
90 # define DS1337_BIT_RS1 0x08
91 # define DS1337_BIT_INTCN 0x04
92 # define DS1337_BIT_A2IE 0x02
93 # define DS1337_BIT_A1IE 0x01
94 #define DS1340_REG_CONTROL 0x07
95 # define DS1340_BIT_OUT 0x80
96 # define DS1340_BIT_FT 0x40
97 # define DS1340_BIT_CALIB_SIGN 0x20
98 # define DS1340_M_CALIBRATION 0x1f
99 #define DS1340_REG_FLAG 0x09
100 # define DS1340_BIT_OSF 0x80
101 #define DS1337_REG_STATUS 0x0f
102 # define DS1337_BIT_OSF 0x80
103 # define DS3231_BIT_EN32KHZ 0x08
104 # define DS1337_BIT_A2I 0x02
105 # define DS1337_BIT_A1I 0x01
106 #define DS1339_REG_ALARM1_SECS 0x07
107
108 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
109
110 #define RX8025_REG_CTRL1 0x0e
111 # define RX8025_BIT_2412 0x20
112 #define RX8025_REG_CTRL2 0x0f
113 # define RX8025_BIT_PON 0x10
114 # define RX8025_BIT_VDET 0x40
115 # define RX8025_BIT_XST 0x20
116
117 struct ds1307 {
118 enum ds_type type;
119 unsigned long flags;
120 #define HAS_NVRAM 0 /* bit 0 == sysfs file active */
121 #define HAS_ALARM 1 /* bit 1 == irq claimed */
122 struct device *dev;
123 struct regmap *regmap;
124 const char *name;
125 struct rtc_device *rtc;
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 u8 offset; /* register's offset */
136 u8 century_reg;
137 u8 century_enable_bit;
138 u8 century_bit;
139 u8 bbsqi_bit;
140 irq_handler_t irq_handler;
141 const struct rtc_class_ops *rtc_ops;
142 u16 trickle_charger_reg;
143 u8 (*do_trickle_setup)(struct ds1307 *, u32,
144 bool);
145 };
146
147 static int ds1307_get_time(struct device *dev, struct rtc_time *t);
148 static int ds1307_set_time(struct device *dev, struct rtc_time *t);
149 static u8 do_trickle_setup_ds1339(struct ds1307 *, u32 ohms, bool diode);
150 static irqreturn_t rx8130_irq(int irq, void *dev_id);
151 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t);
152 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t);
153 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled);
154 static irqreturn_t mcp794xx_irq(int irq, void *dev_id);
155 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t);
156 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t);
157 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled);
158
159 static const struct rtc_class_ops rx8130_rtc_ops = {
160 .read_time = ds1307_get_time,
161 .set_time = ds1307_set_time,
162 .read_alarm = rx8130_read_alarm,
163 .set_alarm = rx8130_set_alarm,
164 .alarm_irq_enable = rx8130_alarm_irq_enable,
165 };
166
167 static const struct rtc_class_ops mcp794xx_rtc_ops = {
168 .read_time = ds1307_get_time,
169 .set_time = ds1307_set_time,
170 .read_alarm = mcp794xx_read_alarm,
171 .set_alarm = mcp794xx_set_alarm,
172 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
173 };
174
175 static const struct chip_desc chips[last_ds_type] = {
176 [ds_1307] = {
177 .nvram_offset = 8,
178 .nvram_size = 56,
179 },
180 [ds_1308] = {
181 .nvram_offset = 8,
182 .nvram_size = 56,
183 },
184 [ds_1337] = {
185 .alarm = 1,
186 .century_reg = DS1307_REG_MONTH,
187 .century_bit = DS1337_BIT_CENTURY,
188 },
189 [ds_1338] = {
190 .nvram_offset = 8,
191 .nvram_size = 56,
192 },
193 [ds_1339] = {
194 .alarm = 1,
195 .century_reg = DS1307_REG_MONTH,
196 .century_bit = DS1337_BIT_CENTURY,
197 .bbsqi_bit = DS1339_BIT_BBSQI,
198 .trickle_charger_reg = 0x10,
199 .do_trickle_setup = &do_trickle_setup_ds1339,
200 },
201 [ds_1340] = {
202 .century_reg = DS1307_REG_HOUR,
203 .century_enable_bit = DS1340_BIT_CENTURY_EN,
204 .century_bit = DS1340_BIT_CENTURY,
205 .do_trickle_setup = &do_trickle_setup_ds1339,
206 .trickle_charger_reg = 0x08,
207 },
208 [ds_1341] = {
209 .century_reg = DS1307_REG_MONTH,
210 .century_bit = DS1337_BIT_CENTURY,
211 },
212 [ds_1388] = {
213 .offset = 1,
214 .trickle_charger_reg = 0x0a,
215 },
216 [ds_3231] = {
217 .alarm = 1,
218 .century_reg = DS1307_REG_MONTH,
219 .century_bit = DS1337_BIT_CENTURY,
220 .bbsqi_bit = DS3231_BIT_BBSQW,
221 },
222 [rx_8130] = {
223 .alarm = 1,
224 /* this is battery backed SRAM */
225 .nvram_offset = 0x20,
226 .nvram_size = 4, /* 32bit (4 word x 8 bit) */
227 .offset = 0x10,
228 .irq_handler = rx8130_irq,
229 .rtc_ops = &rx8130_rtc_ops,
230 },
231 [m41t11] = {
232 /* this is battery backed SRAM */
233 .nvram_offset = 8,
234 .nvram_size = 56,
235 },
236 [mcp794xx] = {
237 .alarm = 1,
238 /* this is battery backed SRAM */
239 .nvram_offset = 0x20,
240 .nvram_size = 0x40,
241 .irq_handler = mcp794xx_irq,
242 .rtc_ops = &mcp794xx_rtc_ops,
243 },
244 };
245
246 static const struct i2c_device_id ds1307_id[] = {
247 { "ds1307", ds_1307 },
248 { "ds1308", ds_1308 },
249 { "ds1337", ds_1337 },
250 { "ds1338", ds_1338 },
251 { "ds1339", ds_1339 },
252 { "ds1388", ds_1388 },
253 { "ds1340", ds_1340 },
254 { "ds1341", ds_1341 },
255 { "ds3231", ds_3231 },
256 { "m41t0", m41t0 },
257 { "m41t00", m41t00 },
258 { "m41t11", m41t11 },
259 { "mcp7940x", mcp794xx },
260 { "mcp7941x", mcp794xx },
261 { "pt7c4338", ds_1307 },
262 { "rx8025", rx_8025 },
263 { "isl12057", ds_1337 },
264 { "rx8130", rx_8130 },
265 { }
266 };
267 MODULE_DEVICE_TABLE(i2c, ds1307_id);
268
269 #ifdef CONFIG_OF
270 static const struct of_device_id ds1307_of_match[] = {
271 {
272 .compatible = "dallas,ds1307",
273 .data = (void *)ds_1307
274 },
275 {
276 .compatible = "dallas,ds1308",
277 .data = (void *)ds_1308
278 },
279 {
280 .compatible = "dallas,ds1337",
281 .data = (void *)ds_1337
282 },
283 {
284 .compatible = "dallas,ds1338",
285 .data = (void *)ds_1338
286 },
287 {
288 .compatible = "dallas,ds1339",
289 .data = (void *)ds_1339
290 },
291 {
292 .compatible = "dallas,ds1388",
293 .data = (void *)ds_1388
294 },
295 {
296 .compatible = "dallas,ds1340",
297 .data = (void *)ds_1340
298 },
299 {
300 .compatible = "dallas,ds1341",
301 .data = (void *)ds_1341
302 },
303 {
304 .compatible = "maxim,ds3231",
305 .data = (void *)ds_3231
306 },
307 {
308 .compatible = "st,m41t0",
309 .data = (void *)m41t0
310 },
311 {
312 .compatible = "st,m41t00",
313 .data = (void *)m41t00
314 },
315 {
316 .compatible = "st,m41t11",
317 .data = (void *)m41t11
318 },
319 {
320 .compatible = "microchip,mcp7940x",
321 .data = (void *)mcp794xx
322 },
323 {
324 .compatible = "microchip,mcp7941x",
325 .data = (void *)mcp794xx
326 },
327 {
328 .compatible = "pericom,pt7c4338",
329 .data = (void *)ds_1307
330 },
331 {
332 .compatible = "epson,rx8025",
333 .data = (void *)rx_8025
334 },
335 {
336 .compatible = "isil,isl12057",
337 .data = (void *)ds_1337
338 },
339 {
340 .compatible = "epson,rx8130",
341 .data = (void *)rx_8130
342 },
343 { }
344 };
345 MODULE_DEVICE_TABLE(of, ds1307_of_match);
346 #endif
347
348 #ifdef CONFIG_ACPI
349 static const struct acpi_device_id ds1307_acpi_ids[] = {
350 { .id = "DS1307", .driver_data = ds_1307 },
351 { .id = "DS1308", .driver_data = ds_1308 },
352 { .id = "DS1337", .driver_data = ds_1337 },
353 { .id = "DS1338", .driver_data = ds_1338 },
354 { .id = "DS1339", .driver_data = ds_1339 },
355 { .id = "DS1388", .driver_data = ds_1388 },
356 { .id = "DS1340", .driver_data = ds_1340 },
357 { .id = "DS1341", .driver_data = ds_1341 },
358 { .id = "DS3231", .driver_data = ds_3231 },
359 { .id = "M41T0", .driver_data = m41t0 },
360 { .id = "M41T00", .driver_data = m41t00 },
361 { .id = "M41T11", .driver_data = m41t11 },
362 { .id = "MCP7940X", .driver_data = mcp794xx },
363 { .id = "MCP7941X", .driver_data = mcp794xx },
364 { .id = "PT7C4338", .driver_data = ds_1307 },
365 { .id = "RX8025", .driver_data = rx_8025 },
366 { .id = "ISL12057", .driver_data = ds_1337 },
367 { .id = "RX8130", .driver_data = rx_8130 },
368 { }
369 };
370 MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
371 #endif
372
373 /*
374 * The ds1337 and ds1339 both have two alarms, but we only use the first
375 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
376 * signal; ds1339 chips have only one alarm signal.
377 */
378 static irqreturn_t ds1307_irq(int irq, void *dev_id)
379 {
380 struct ds1307 *ds1307 = dev_id;
381 struct mutex *lock = &ds1307->rtc->ops_lock;
382 int stat, ret;
383
384 mutex_lock(lock);
385 ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat);
386 if (ret)
387 goto out;
388
389 if (stat & DS1337_BIT_A1I) {
390 stat &= ~DS1337_BIT_A1I;
391 regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat);
392
393 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
394 DS1337_BIT_A1IE, 0);
395 if (ret)
396 goto out;
397
398 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
399 }
400
401 out:
402 mutex_unlock(lock);
403
404 return IRQ_HANDLED;
405 }
406
407 /*----------------------------------------------------------------------*/
408
409 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
410 {
411 struct ds1307 *ds1307 = dev_get_drvdata(dev);
412 int tmp, ret;
413 const struct chip_desc *chip = &chips[ds1307->type];
414 u8 regs[7];
415
416 /* read the RTC date and time registers all at once */
417 ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
418 sizeof(regs));
419 if (ret) {
420 dev_err(dev, "%s error %d\n", "read", ret);
421 return ret;
422 }
423
424 dev_dbg(dev, "%s: %7ph\n", "read", regs);
425
426 /* if oscillator fail bit is set, no data can be trusted */
427 if (ds1307->type == m41t0 &&
428 regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
429 dev_warn_once(dev, "oscillator failed, set time!\n");
430 return -EINVAL;
431 }
432
433 t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f);
434 t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
435 tmp = regs[DS1307_REG_HOUR] & 0x3f;
436 t->tm_hour = bcd2bin(tmp);
437 t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
438 t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
439 tmp = regs[DS1307_REG_MONTH] & 0x1f;
440 t->tm_mon = bcd2bin(tmp) - 1;
441 t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
442
443 if (regs[chip->century_reg] & chip->century_bit &&
444 IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
445 t->tm_year += 100;
446
447 dev_dbg(dev, "%s secs=%d, mins=%d, "
448 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
449 "read", t->tm_sec, t->tm_min,
450 t->tm_hour, t->tm_mday,
451 t->tm_mon, t->tm_year, t->tm_wday);
452
453 return 0;
454 }
455
456 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
457 {
458 struct ds1307 *ds1307 = dev_get_drvdata(dev);
459 const struct chip_desc *chip = &chips[ds1307->type];
460 int result;
461 int tmp;
462 u8 regs[7];
463
464 dev_dbg(dev, "%s secs=%d, mins=%d, "
465 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
466 "write", t->tm_sec, t->tm_min,
467 t->tm_hour, t->tm_mday,
468 t->tm_mon, t->tm_year, t->tm_wday);
469
470 if (t->tm_year < 100)
471 return -EINVAL;
472
473 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
474 if (t->tm_year > (chip->century_bit ? 299 : 199))
475 return -EINVAL;
476 #else
477 if (t->tm_year > 199)
478 return -EINVAL;
479 #endif
480
481 regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
482 regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
483 regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
484 regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
485 regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
486 regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
487
488 /* assume 20YY not 19YY */
489 tmp = t->tm_year - 100;
490 regs[DS1307_REG_YEAR] = bin2bcd(tmp);
491
492 if (chip->century_enable_bit)
493 regs[chip->century_reg] |= chip->century_enable_bit;
494 if (t->tm_year > 199 && chip->century_bit)
495 regs[chip->century_reg] |= chip->century_bit;
496
497 if (ds1307->type == mcp794xx) {
498 /*
499 * these bits were cleared when preparing the date/time
500 * values and need to be set again before writing the
501 * regsfer out to the device.
502 */
503 regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
504 regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
505 }
506
507 dev_dbg(dev, "%s: %7ph\n", "write", regs);
508
509 result = regmap_bulk_write(ds1307->regmap, chip->offset, regs,
510 sizeof(regs));
511 if (result) {
512 dev_err(dev, "%s error %d\n", "write", result);
513 return result;
514 }
515 return 0;
516 }
517
518 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
519 {
520 struct ds1307 *ds1307 = dev_get_drvdata(dev);
521 int ret;
522 u8 regs[9];
523
524 if (!test_bit(HAS_ALARM, &ds1307->flags))
525 return -EINVAL;
526
527 /* read all ALARM1, ALARM2, and status registers at once */
528 ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
529 regs, sizeof(regs));
530 if (ret) {
531 dev_err(dev, "%s error %d\n", "alarm read", ret);
532 return ret;
533 }
534
535 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
536 &regs[0], &regs[4], &regs[7]);
537
538 /*
539 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
540 * and that all four fields are checked matches
541 */
542 t->time.tm_sec = bcd2bin(regs[0] & 0x7f);
543 t->time.tm_min = bcd2bin(regs[1] & 0x7f);
544 t->time.tm_hour = bcd2bin(regs[2] & 0x3f);
545 t->time.tm_mday = bcd2bin(regs[3] & 0x3f);
546
547 /* ... and status */
548 t->enabled = !!(regs[7] & DS1337_BIT_A1IE);
549 t->pending = !!(regs[8] & DS1337_BIT_A1I);
550
551 dev_dbg(dev, "%s secs=%d, mins=%d, "
552 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
553 "alarm read", t->time.tm_sec, t->time.tm_min,
554 t->time.tm_hour, t->time.tm_mday,
555 t->enabled, t->pending);
556
557 return 0;
558 }
559
560 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
561 {
562 struct ds1307 *ds1307 = dev_get_drvdata(dev);
563 unsigned char regs[9];
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 = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
578 sizeof(regs));
579 if (ret) {
580 dev_err(dev, "%s error %d\n", "alarm write", ret);
581 return ret;
582 }
583 control = regs[7];
584 status = regs[8];
585
586 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
587 &regs[0], &regs[4], control, status);
588
589 /* set ALARM1, using 24 hour and day-of-month modes */
590 regs[0] = bin2bcd(t->time.tm_sec);
591 regs[1] = bin2bcd(t->time.tm_min);
592 regs[2] = bin2bcd(t->time.tm_hour);
593 regs[3] = bin2bcd(t->time.tm_mday);
594
595 /* set ALARM2 to non-garbage */
596 regs[4] = 0;
597 regs[5] = 0;
598 regs[6] = 0;
599
600 /* disable alarms */
601 regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
602 regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
603
604 ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
605 sizeof(regs));
606 if (ret) {
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 regs[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
615 regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]);
616 }
617
618 return 0;
619 }
620
621 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
622 {
623 struct ds1307 *ds1307 = dev_get_drvdata(dev);
624
625 if (!test_bit(HAS_ALARM, &ds1307->flags))
626 return -ENOTTY;
627
628 return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
629 DS1337_BIT_A1IE,
630 enabled ? DS1337_BIT_A1IE : 0);
631 }
632
633 static const struct rtc_class_ops ds13xx_rtc_ops = {
634 .read_time = ds1307_get_time,
635 .set_time = ds1307_set_time,
636 .read_alarm = ds1337_read_alarm,
637 .set_alarm = ds1337_set_alarm,
638 .alarm_irq_enable = ds1307_alarm_irq_enable,
639 };
640
641 /*----------------------------------------------------------------------*/
642
643 /*
644 * Alarm support for rx8130 devices.
645 */
646
647 #define RX8130_REG_ALARM_MIN 0x07
648 #define RX8130_REG_ALARM_HOUR 0x08
649 #define RX8130_REG_ALARM_WEEK_OR_DAY 0x09
650 #define RX8130_REG_EXTENSION 0x0c
651 #define RX8130_REG_EXTENSION_WADA BIT(3)
652 #define RX8130_REG_FLAG 0x0d
653 #define RX8130_REG_FLAG_AF BIT(3)
654 #define RX8130_REG_CONTROL0 0x0e
655 #define RX8130_REG_CONTROL0_AIE BIT(3)
656
657 static irqreturn_t rx8130_irq(int irq, void *dev_id)
658 {
659 struct ds1307 *ds1307 = dev_id;
660 struct mutex *lock = &ds1307->rtc->ops_lock;
661 u8 ctl[3];
662 int ret;
663
664 mutex_lock(lock);
665
666 /* Read control registers. */
667 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
668 sizeof(ctl));
669 if (ret < 0)
670 goto out;
671 if (!(ctl[1] & RX8130_REG_FLAG_AF))
672 goto out;
673 ctl[1] &= ~RX8130_REG_FLAG_AF;
674 ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
675
676 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
677 sizeof(ctl));
678 if (ret < 0)
679 goto out;
680
681 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
682
683 out:
684 mutex_unlock(lock);
685
686 return IRQ_HANDLED;
687 }
688
689 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t)
690 {
691 struct ds1307 *ds1307 = dev_get_drvdata(dev);
692 u8 ald[3], ctl[3];
693 int ret;
694
695 if (!test_bit(HAS_ALARM, &ds1307->flags))
696 return -EINVAL;
697
698 /* Read alarm registers. */
699 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
700 sizeof(ald));
701 if (ret < 0)
702 return ret;
703
704 /* Read control registers. */
705 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
706 sizeof(ctl));
707 if (ret < 0)
708 return ret;
709
710 t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE);
711 t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF);
712
713 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
714 t->time.tm_sec = -1;
715 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
716 t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
717 t->time.tm_wday = -1;
718 t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
719 t->time.tm_mon = -1;
720 t->time.tm_year = -1;
721 t->time.tm_yday = -1;
722 t->time.tm_isdst = -1;
723
724 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
725 __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
726 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
727
728 return 0;
729 }
730
731 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t)
732 {
733 struct ds1307 *ds1307 = dev_get_drvdata(dev);
734 u8 ald[3], ctl[3];
735 int ret;
736
737 if (!test_bit(HAS_ALARM, &ds1307->flags))
738 return -EINVAL;
739
740 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
741 "enabled=%d pending=%d\n", __func__,
742 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
743 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
744 t->enabled, t->pending);
745
746 /* Read control registers. */
747 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
748 sizeof(ctl));
749 if (ret < 0)
750 return ret;
751
752 ctl[0] &= ~RX8130_REG_EXTENSION_WADA;
753 ctl[1] |= RX8130_REG_FLAG_AF;
754 ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
755
756 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
757 sizeof(ctl));
758 if (ret < 0)
759 return ret;
760
761 /* Hardware alarm precision is 1 minute! */
762 ald[0] = bin2bcd(t->time.tm_min);
763 ald[1] = bin2bcd(t->time.tm_hour);
764 ald[2] = bin2bcd(t->time.tm_mday);
765
766 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
767 sizeof(ald));
768 if (ret < 0)
769 return ret;
770
771 if (!t->enabled)
772 return 0;
773
774 ctl[2] |= RX8130_REG_CONTROL0_AIE;
775
776 return regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
777 sizeof(ctl));
778 }
779
780 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled)
781 {
782 struct ds1307 *ds1307 = dev_get_drvdata(dev);
783 int ret, reg;
784
785 if (!test_bit(HAS_ALARM, &ds1307->flags))
786 return -EINVAL;
787
788 ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, &reg);
789 if (ret < 0)
790 return ret;
791
792 if (enabled)
793 reg |= RX8130_REG_CONTROL0_AIE;
794 else
795 reg &= ~RX8130_REG_CONTROL0_AIE;
796
797 return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg);
798 }
799
800 /*----------------------------------------------------------------------*/
801
802 /*
803 * Alarm support for mcp794xx devices.
804 */
805
806 #define MCP794XX_REG_CONTROL 0x07
807 # define MCP794XX_BIT_ALM0_EN 0x10
808 # define MCP794XX_BIT_ALM1_EN 0x20
809 #define MCP794XX_REG_ALARM0_BASE 0x0a
810 #define MCP794XX_REG_ALARM0_CTRL 0x0d
811 #define MCP794XX_REG_ALARM1_BASE 0x11
812 #define MCP794XX_REG_ALARM1_CTRL 0x14
813 # define MCP794XX_BIT_ALMX_IF BIT(3)
814 # define MCP794XX_BIT_ALMX_C0 BIT(4)
815 # define MCP794XX_BIT_ALMX_C1 BIT(5)
816 # define MCP794XX_BIT_ALMX_C2 BIT(6)
817 # define MCP794XX_BIT_ALMX_POL BIT(7)
818 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
819 MCP794XX_BIT_ALMX_C1 | \
820 MCP794XX_BIT_ALMX_C2)
821
822 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
823 {
824 struct ds1307 *ds1307 = dev_id;
825 struct mutex *lock = &ds1307->rtc->ops_lock;
826 int reg, ret;
827
828 mutex_lock(lock);
829
830 /* Check and clear alarm 0 interrupt flag. */
831 ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, &reg);
832 if (ret)
833 goto out;
834 if (!(reg & MCP794XX_BIT_ALMX_IF))
835 goto out;
836 reg &= ~MCP794XX_BIT_ALMX_IF;
837 ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg);
838 if (ret)
839 goto out;
840
841 /* Disable alarm 0. */
842 ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
843 MCP794XX_BIT_ALM0_EN, 0);
844 if (ret)
845 goto out;
846
847 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
848
849 out:
850 mutex_unlock(lock);
851
852 return IRQ_HANDLED;
853 }
854
855 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
856 {
857 struct ds1307 *ds1307 = dev_get_drvdata(dev);
858 u8 regs[10];
859 int ret;
860
861 if (!test_bit(HAS_ALARM, &ds1307->flags))
862 return -EINVAL;
863
864 /* Read control and alarm 0 registers. */
865 ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
866 sizeof(regs));
867 if (ret)
868 return ret;
869
870 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
871
872 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
873 t->time.tm_sec = bcd2bin(regs[3] & 0x7f);
874 t->time.tm_min = bcd2bin(regs[4] & 0x7f);
875 t->time.tm_hour = bcd2bin(regs[5] & 0x3f);
876 t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1;
877 t->time.tm_mday = bcd2bin(regs[7] & 0x3f);
878 t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
879 t->time.tm_year = -1;
880 t->time.tm_yday = -1;
881 t->time.tm_isdst = -1;
882
883 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
884 "enabled=%d polarity=%d irq=%d match=%lu\n", __func__,
885 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
886 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
887 !!(regs[6] & MCP794XX_BIT_ALMX_POL),
888 !!(regs[6] & MCP794XX_BIT_ALMX_IF),
889 (regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
890
891 return 0;
892 }
893
894 /*
895 * We may have a random RTC weekday, therefore calculate alarm weekday based
896 * on current weekday we read from the RTC timekeeping regs
897 */
898 static int mcp794xx_alm_weekday(struct device *dev, struct rtc_time *tm_alarm)
899 {
900 struct rtc_time tm_now;
901 int days_now, days_alarm, ret;
902
903 ret = ds1307_get_time(dev, &tm_now);
904 if (ret)
905 return ret;
906
907 days_now = div_s64(rtc_tm_to_time64(&tm_now), 24 * 60 * 60);
908 days_alarm = div_s64(rtc_tm_to_time64(tm_alarm), 24 * 60 * 60);
909
910 return (tm_now.tm_wday + days_alarm - days_now) % 7 + 1;
911 }
912
913 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
914 {
915 struct ds1307 *ds1307 = dev_get_drvdata(dev);
916 unsigned char regs[10];
917 int wday, ret;
918
919 if (!test_bit(HAS_ALARM, &ds1307->flags))
920 return -EINVAL;
921
922 wday = mcp794xx_alm_weekday(dev, &t->time);
923 if (wday < 0)
924 return wday;
925
926 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
927 "enabled=%d pending=%d\n", __func__,
928 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
929 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
930 t->enabled, t->pending);
931
932 /* Read control and alarm 0 registers. */
933 ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
934 sizeof(regs));
935 if (ret)
936 return ret;
937
938 /* Set alarm 0, using 24-hour and day-of-month modes. */
939 regs[3] = bin2bcd(t->time.tm_sec);
940 regs[4] = bin2bcd(t->time.tm_min);
941 regs[5] = bin2bcd(t->time.tm_hour);
942 regs[6] = wday;
943 regs[7] = bin2bcd(t->time.tm_mday);
944 regs[8] = bin2bcd(t->time.tm_mon + 1);
945
946 /* Clear the alarm 0 interrupt flag. */
947 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
948 /* Set alarm match: second, minute, hour, day, date, month. */
949 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
950 /* Disable interrupt. We will not enable until completely programmed */
951 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
952
953 ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
954 sizeof(regs));
955 if (ret)
956 return ret;
957
958 if (!t->enabled)
959 return 0;
960 regs[0] |= MCP794XX_BIT_ALM0_EN;
961 return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]);
962 }
963
964 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
965 {
966 struct ds1307 *ds1307 = dev_get_drvdata(dev);
967
968 if (!test_bit(HAS_ALARM, &ds1307->flags))
969 return -EINVAL;
970
971 return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
972 MCP794XX_BIT_ALM0_EN,
973 enabled ? MCP794XX_BIT_ALM0_EN : 0);
974 }
975
976 /*----------------------------------------------------------------------*/
977
978 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
979 size_t bytes)
980 {
981 struct ds1307 *ds1307 = priv;
982 const struct chip_desc *chip = &chips[ds1307->type];
983
984 return regmap_bulk_read(ds1307->regmap, chip->nvram_offset + offset,
985 val, bytes);
986 }
987
988 static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
989 size_t bytes)
990 {
991 struct ds1307 *ds1307 = priv;
992 const struct chip_desc *chip = &chips[ds1307->type];
993
994 return regmap_bulk_write(ds1307->regmap, chip->nvram_offset + offset,
995 val, bytes);
996 }
997
998 /*----------------------------------------------------------------------*/
999
1000 static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307,
1001 u32 ohms, bool diode)
1002 {
1003 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
1004 DS1307_TRICKLE_CHARGER_NO_DIODE;
1005
1006 switch (ohms) {
1007 case 250:
1008 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
1009 break;
1010 case 2000:
1011 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
1012 break;
1013 case 4000:
1014 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
1015 break;
1016 default:
1017 dev_warn(ds1307->dev,
1018 "Unsupported ohm value %u in dt\n", ohms);
1019 return 0;
1020 }
1021 return setup;
1022 }
1023
1024 static u8 ds1307_trickle_init(struct ds1307 *ds1307,
1025 const struct chip_desc *chip)
1026 {
1027 u32 ohms;
1028 bool diode = true;
1029
1030 if (!chip->do_trickle_setup)
1031 return 0;
1032
1033 if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
1034 &ohms))
1035 return 0;
1036
1037 if (device_property_read_bool(ds1307->dev, "trickle-diode-disable"))
1038 diode = false;
1039
1040 return chip->do_trickle_setup(ds1307, ohms, diode);
1041 }
1042
1043 /*----------------------------------------------------------------------*/
1044
1045 #if IS_REACHABLE(CONFIG_HWMON)
1046
1047 /*
1048 * Temperature sensor support for ds3231 devices.
1049 */
1050
1051 #define DS3231_REG_TEMPERATURE 0x11
1052
1053 /*
1054 * A user-initiated temperature conversion is not started by this function,
1055 * so the temperature is updated once every 64 seconds.
1056 */
1057 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
1058 {
1059 struct ds1307 *ds1307 = dev_get_drvdata(dev);
1060 u8 temp_buf[2];
1061 s16 temp;
1062 int ret;
1063
1064 ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE,
1065 temp_buf, sizeof(temp_buf));
1066 if (ret)
1067 return ret;
1068 /*
1069 * Temperature is represented as a 10-bit code with a resolution of
1070 * 0.25 degree celsius and encoded in two's complement format.
1071 */
1072 temp = (temp_buf[0] << 8) | temp_buf[1];
1073 temp >>= 6;
1074 *mC = temp * 250;
1075
1076 return 0;
1077 }
1078
1079 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
1080 struct device_attribute *attr, char *buf)
1081 {
1082 int ret;
1083 s32 temp;
1084
1085 ret = ds3231_hwmon_read_temp(dev, &temp);
1086 if (ret)
1087 return ret;
1088
1089 return sprintf(buf, "%d\n", temp);
1090 }
1091 static SENSOR_DEVICE_ATTR(temp1_input, 0444, ds3231_hwmon_show_temp,
1092 NULL, 0);
1093
1094 static struct attribute *ds3231_hwmon_attrs[] = {
1095 &sensor_dev_attr_temp1_input.dev_attr.attr,
1096 NULL,
1097 };
1098 ATTRIBUTE_GROUPS(ds3231_hwmon);
1099
1100 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1101 {
1102 struct device *dev;
1103
1104 if (ds1307->type != ds_3231)
1105 return;
1106
1107 dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name,
1108 ds1307,
1109 ds3231_hwmon_groups);
1110 if (IS_ERR(dev)) {
1111 dev_warn(ds1307->dev, "unable to register hwmon device %ld\n",
1112 PTR_ERR(dev));
1113 }
1114 }
1115
1116 #else
1117
1118 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1119 {
1120 }
1121
1122 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
1123
1124 /*----------------------------------------------------------------------*/
1125
1126 /*
1127 * Square-wave output support for DS3231
1128 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1129 */
1130 #ifdef CONFIG_COMMON_CLK
1131
1132 enum {
1133 DS3231_CLK_SQW = 0,
1134 DS3231_CLK_32KHZ,
1135 };
1136
1137 #define clk_sqw_to_ds1307(clk) \
1138 container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1139 #define clk_32khz_to_ds1307(clk) \
1140 container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1141
1142 static int ds3231_clk_sqw_rates[] = {
1143 1,
1144 1024,
1145 4096,
1146 8192,
1147 };
1148
1149 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1150 {
1151 struct mutex *lock = &ds1307->rtc->ops_lock;
1152 int ret;
1153
1154 mutex_lock(lock);
1155 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1156 mask, value);
1157 mutex_unlock(lock);
1158
1159 return ret;
1160 }
1161
1162 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1163 unsigned long parent_rate)
1164 {
1165 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1166 int control, ret;
1167 int rate_sel = 0;
1168
1169 ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1170 if (ret)
1171 return ret;
1172 if (control & DS1337_BIT_RS1)
1173 rate_sel += 1;
1174 if (control & DS1337_BIT_RS2)
1175 rate_sel += 2;
1176
1177 return ds3231_clk_sqw_rates[rate_sel];
1178 }
1179
1180 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1181 unsigned long *prate)
1182 {
1183 int i;
1184
1185 for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1186 if (ds3231_clk_sqw_rates[i] <= rate)
1187 return ds3231_clk_sqw_rates[i];
1188 }
1189
1190 return 0;
1191 }
1192
1193 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1194 unsigned long parent_rate)
1195 {
1196 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1197 int control = 0;
1198 int rate_sel;
1199
1200 for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1201 rate_sel++) {
1202 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1203 break;
1204 }
1205
1206 if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1207 return -EINVAL;
1208
1209 if (rate_sel & 1)
1210 control |= DS1337_BIT_RS1;
1211 if (rate_sel & 2)
1212 control |= DS1337_BIT_RS2;
1213
1214 return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1215 control);
1216 }
1217
1218 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1219 {
1220 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1221
1222 return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1223 }
1224
1225 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1226 {
1227 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1228
1229 ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1230 }
1231
1232 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1233 {
1234 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1235 int control, ret;
1236
1237 ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1238 if (ret)
1239 return ret;
1240
1241 return !(control & DS1337_BIT_INTCN);
1242 }
1243
1244 static const struct clk_ops ds3231_clk_sqw_ops = {
1245 .prepare = ds3231_clk_sqw_prepare,
1246 .unprepare = ds3231_clk_sqw_unprepare,
1247 .is_prepared = ds3231_clk_sqw_is_prepared,
1248 .recalc_rate = ds3231_clk_sqw_recalc_rate,
1249 .round_rate = ds3231_clk_sqw_round_rate,
1250 .set_rate = ds3231_clk_sqw_set_rate,
1251 };
1252
1253 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1254 unsigned long parent_rate)
1255 {
1256 return 32768;
1257 }
1258
1259 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1260 {
1261 struct mutex *lock = &ds1307->rtc->ops_lock;
1262 int ret;
1263
1264 mutex_lock(lock);
1265 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS,
1266 DS3231_BIT_EN32KHZ,
1267 enable ? DS3231_BIT_EN32KHZ : 0);
1268 mutex_unlock(lock);
1269
1270 return ret;
1271 }
1272
1273 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1274 {
1275 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1276
1277 return ds3231_clk_32khz_control(ds1307, true);
1278 }
1279
1280 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1281 {
1282 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1283
1284 ds3231_clk_32khz_control(ds1307, false);
1285 }
1286
1287 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1288 {
1289 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1290 int status, ret;
1291
1292 ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status);
1293 if (ret)
1294 return ret;
1295
1296 return !!(status & DS3231_BIT_EN32KHZ);
1297 }
1298
1299 static const struct clk_ops ds3231_clk_32khz_ops = {
1300 .prepare = ds3231_clk_32khz_prepare,
1301 .unprepare = ds3231_clk_32khz_unprepare,
1302 .is_prepared = ds3231_clk_32khz_is_prepared,
1303 .recalc_rate = ds3231_clk_32khz_recalc_rate,
1304 };
1305
1306 static struct clk_init_data ds3231_clks_init[] = {
1307 [DS3231_CLK_SQW] = {
1308 .name = "ds3231_clk_sqw",
1309 .ops = &ds3231_clk_sqw_ops,
1310 },
1311 [DS3231_CLK_32KHZ] = {
1312 .name = "ds3231_clk_32khz",
1313 .ops = &ds3231_clk_32khz_ops,
1314 },
1315 };
1316
1317 static int ds3231_clks_register(struct ds1307 *ds1307)
1318 {
1319 struct device_node *node = ds1307->dev->of_node;
1320 struct clk_onecell_data *onecell;
1321 int i;
1322
1323 onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL);
1324 if (!onecell)
1325 return -ENOMEM;
1326
1327 onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1328 onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num,
1329 sizeof(onecell->clks[0]), GFP_KERNEL);
1330 if (!onecell->clks)
1331 return -ENOMEM;
1332
1333 for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1334 struct clk_init_data init = ds3231_clks_init[i];
1335
1336 /*
1337 * Interrupt signal due to alarm conditions and square-wave
1338 * output share same pin, so don't initialize both.
1339 */
1340 if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1341 continue;
1342
1343 /* optional override of the clockname */
1344 of_property_read_string_index(node, "clock-output-names", i,
1345 &init.name);
1346 ds1307->clks[i].init = &init;
1347
1348 onecell->clks[i] = devm_clk_register(ds1307->dev,
1349 &ds1307->clks[i]);
1350 if (IS_ERR(onecell->clks[i]))
1351 return PTR_ERR(onecell->clks[i]);
1352 }
1353
1354 if (!node)
1355 return 0;
1356
1357 of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1358
1359 return 0;
1360 }
1361
1362 static void ds1307_clks_register(struct ds1307 *ds1307)
1363 {
1364 int ret;
1365
1366 if (ds1307->type != ds_3231)
1367 return;
1368
1369 ret = ds3231_clks_register(ds1307);
1370 if (ret) {
1371 dev_warn(ds1307->dev, "unable to register clock device %d\n",
1372 ret);
1373 }
1374 }
1375
1376 #else
1377
1378 static void ds1307_clks_register(struct ds1307 *ds1307)
1379 {
1380 }
1381
1382 #endif /* CONFIG_COMMON_CLK */
1383
1384 static const struct regmap_config regmap_config = {
1385 .reg_bits = 8,
1386 .val_bits = 8,
1387 .max_register = 0x9,
1388 };
1389
1390 static int ds1307_probe(struct i2c_client *client,
1391 const struct i2c_device_id *id)
1392 {
1393 struct ds1307 *ds1307;
1394 int err = -ENODEV;
1395 int tmp;
1396 const struct chip_desc *chip;
1397 bool want_irq;
1398 bool ds1307_can_wakeup_device = false;
1399 unsigned char regs[8];
1400 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1401 u8 trickle_charger_setup = 0;
1402
1403 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1404 if (!ds1307)
1405 return -ENOMEM;
1406
1407 dev_set_drvdata(&client->dev, ds1307);
1408 ds1307->dev = &client->dev;
1409 ds1307->name = client->name;
1410
1411 ds1307->regmap = devm_regmap_init_i2c(client, &regmap_config);
1412 if (IS_ERR(ds1307->regmap)) {
1413 dev_err(ds1307->dev, "regmap allocation failed\n");
1414 return PTR_ERR(ds1307->regmap);
1415 }
1416
1417 i2c_set_clientdata(client, ds1307);
1418
1419 if (client->dev.of_node) {
1420 ds1307->type = (enum ds_type)
1421 of_device_get_match_data(&client->dev);
1422 chip = &chips[ds1307->type];
1423 } else if (id) {
1424 chip = &chips[id->driver_data];
1425 ds1307->type = id->driver_data;
1426 } else {
1427 const struct acpi_device_id *acpi_id;
1428
1429 acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1430 ds1307->dev);
1431 if (!acpi_id)
1432 return -ENODEV;
1433 chip = &chips[acpi_id->driver_data];
1434 ds1307->type = acpi_id->driver_data;
1435 }
1436
1437 want_irq = client->irq > 0 && chip->alarm;
1438
1439 if (!pdata)
1440 trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
1441 else if (pdata->trickle_charger_setup)
1442 trickle_charger_setup = pdata->trickle_charger_setup;
1443
1444 if (trickle_charger_setup && chip->trickle_charger_reg) {
1445 trickle_charger_setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
1446 dev_dbg(ds1307->dev,
1447 "writing trickle charger info 0x%x to 0x%x\n",
1448 trickle_charger_setup, chip->trickle_charger_reg);
1449 regmap_write(ds1307->regmap, chip->trickle_charger_reg,
1450 trickle_charger_setup);
1451 }
1452
1453 #ifdef CONFIG_OF
1454 /*
1455 * For devices with no IRQ directly connected to the SoC, the RTC chip
1456 * can be forced as a wakeup source by stating that explicitly in
1457 * the device's .dts file using the "wakeup-source" boolean property.
1458 * If the "wakeup-source" property is set, don't request an IRQ.
1459 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1460 * if supported by the RTC.
1461 */
1462 if (chip->alarm && of_property_read_bool(client->dev.of_node,
1463 "wakeup-source"))
1464 ds1307_can_wakeup_device = true;
1465 #endif
1466
1467 switch (ds1307->type) {
1468 case ds_1337:
1469 case ds_1339:
1470 case ds_1341:
1471 case ds_3231:
1472 /* get registers that the "rtc" read below won't read... */
1473 err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
1474 regs, 2);
1475 if (err) {
1476 dev_dbg(ds1307->dev, "read error %d\n", err);
1477 goto exit;
1478 }
1479
1480 /* oscillator off? turn it on, so clock can tick. */
1481 if (regs[0] & DS1337_BIT_nEOSC)
1482 regs[0] &= ~DS1337_BIT_nEOSC;
1483
1484 /*
1485 * Using IRQ or defined as wakeup-source?
1486 * Disable the square wave and both alarms.
1487 * For some variants, be sure alarms can trigger when we're
1488 * running on Vbackup (BBSQI/BBSQW)
1489 */
1490 if (want_irq || ds1307_can_wakeup_device) {
1491 regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
1492 regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1493 }
1494
1495 regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
1496 regs[0]);
1497
1498 /* oscillator fault? clear flag, and warn */
1499 if (regs[1] & DS1337_BIT_OSF) {
1500 regmap_write(ds1307->regmap, DS1337_REG_STATUS,
1501 regs[1] & ~DS1337_BIT_OSF);
1502 dev_warn(ds1307->dev, "SET TIME!\n");
1503 }
1504 break;
1505
1506 case rx_8025:
1507 err = regmap_bulk_read(ds1307->regmap,
1508 RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
1509 if (err) {
1510 dev_dbg(ds1307->dev, "read error %d\n", err);
1511 goto exit;
1512 }
1513
1514 /* oscillator off? turn it on, so clock can tick. */
1515 if (!(regs[1] & RX8025_BIT_XST)) {
1516 regs[1] |= RX8025_BIT_XST;
1517 regmap_write(ds1307->regmap,
1518 RX8025_REG_CTRL2 << 4 | 0x08,
1519 regs[1]);
1520 dev_warn(ds1307->dev,
1521 "oscillator stop detected - SET TIME!\n");
1522 }
1523
1524 if (regs[1] & RX8025_BIT_PON) {
1525 regs[1] &= ~RX8025_BIT_PON;
1526 regmap_write(ds1307->regmap,
1527 RX8025_REG_CTRL2 << 4 | 0x08,
1528 regs[1]);
1529 dev_warn(ds1307->dev, "power-on detected\n");
1530 }
1531
1532 if (regs[1] & RX8025_BIT_VDET) {
1533 regs[1] &= ~RX8025_BIT_VDET;
1534 regmap_write(ds1307->regmap,
1535 RX8025_REG_CTRL2 << 4 | 0x08,
1536 regs[1]);
1537 dev_warn(ds1307->dev, "voltage drop detected\n");
1538 }
1539
1540 /* make sure we are running in 24hour mode */
1541 if (!(regs[0] & RX8025_BIT_2412)) {
1542 u8 hour;
1543
1544 /* switch to 24 hour mode */
1545 regmap_write(ds1307->regmap,
1546 RX8025_REG_CTRL1 << 4 | 0x08,
1547 regs[0] | RX8025_BIT_2412);
1548
1549 err = regmap_bulk_read(ds1307->regmap,
1550 RX8025_REG_CTRL1 << 4 | 0x08,
1551 regs, 2);
1552 if (err) {
1553 dev_dbg(ds1307->dev, "read error %d\n", err);
1554 goto exit;
1555 }
1556
1557 /* correct hour */
1558 hour = bcd2bin(regs[DS1307_REG_HOUR]);
1559 if (hour == 12)
1560 hour = 0;
1561 if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1562 hour += 12;
1563
1564 regmap_write(ds1307->regmap,
1565 DS1307_REG_HOUR << 4 | 0x08, hour);
1566 }
1567 break;
1568 default:
1569 break;
1570 }
1571
1572 read_rtc:
1573 /* read RTC registers */
1574 err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
1575 sizeof(regs));
1576 if (err) {
1577 dev_dbg(ds1307->dev, "read error %d\n", err);
1578 goto exit;
1579 }
1580
1581 /*
1582 * minimal sanity checking; some chips (like DS1340) don't
1583 * specify the extra bits as must-be-zero, but there are
1584 * still a few values that are clearly out-of-range.
1585 */
1586 tmp = regs[DS1307_REG_SECS];
1587 switch (ds1307->type) {
1588 case ds_1307:
1589 case m41t0:
1590 case m41t00:
1591 case m41t11:
1592 /* clock halted? turn it on, so clock can tick. */
1593 if (tmp & DS1307_BIT_CH) {
1594 regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1595 dev_warn(ds1307->dev, "SET TIME!\n");
1596 goto read_rtc;
1597 }
1598 break;
1599 case ds_1308:
1600 case ds_1338:
1601 /* clock halted? turn it on, so clock can tick. */
1602 if (tmp & DS1307_BIT_CH)
1603 regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1604
1605 /* oscillator fault? clear flag, and warn */
1606 if (regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1607 regmap_write(ds1307->regmap, DS1307_REG_CONTROL,
1608 regs[DS1307_REG_CONTROL] &
1609 ~DS1338_BIT_OSF);
1610 dev_warn(ds1307->dev, "SET TIME!\n");
1611 goto read_rtc;
1612 }
1613 break;
1614 case ds_1340:
1615 /* clock halted? turn it on, so clock can tick. */
1616 if (tmp & DS1340_BIT_nEOSC)
1617 regmap_write(ds1307->regmap, DS1307_REG_SECS, 0);
1618
1619 err = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp);
1620 if (err) {
1621 dev_dbg(ds1307->dev, "read error %d\n", err);
1622 goto exit;
1623 }
1624
1625 /* oscillator fault? clear flag, and warn */
1626 if (tmp & DS1340_BIT_OSF) {
1627 regmap_write(ds1307->regmap, DS1340_REG_FLAG, 0);
1628 dev_warn(ds1307->dev, "SET TIME!\n");
1629 }
1630 break;
1631 case mcp794xx:
1632 /* make sure that the backup battery is enabled */
1633 if (!(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1634 regmap_write(ds1307->regmap, DS1307_REG_WDAY,
1635 regs[DS1307_REG_WDAY] |
1636 MCP794XX_BIT_VBATEN);
1637 }
1638
1639 /* clock halted? turn it on, so clock can tick. */
1640 if (!(tmp & MCP794XX_BIT_ST)) {
1641 regmap_write(ds1307->regmap, DS1307_REG_SECS,
1642 MCP794XX_BIT_ST);
1643 dev_warn(ds1307->dev, "SET TIME!\n");
1644 goto read_rtc;
1645 }
1646
1647 break;
1648 default:
1649 break;
1650 }
1651
1652 tmp = regs[DS1307_REG_HOUR];
1653 switch (ds1307->type) {
1654 case ds_1340:
1655 case m41t0:
1656 case m41t00:
1657 case m41t11:
1658 /*
1659 * NOTE: ignores century bits; fix before deploying
1660 * systems that will run through year 2100.
1661 */
1662 break;
1663 case rx_8025:
1664 break;
1665 default:
1666 if (!(tmp & DS1307_BIT_12HR))
1667 break;
1668
1669 /*
1670 * Be sure we're in 24 hour mode. Multi-master systems
1671 * take note...
1672 */
1673 tmp = bcd2bin(tmp & 0x1f);
1674 if (tmp == 12)
1675 tmp = 0;
1676 if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1677 tmp += 12;
1678 regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
1679 bin2bcd(tmp));
1680 }
1681
1682 if (want_irq || ds1307_can_wakeup_device) {
1683 device_set_wakeup_capable(ds1307->dev, true);
1684 set_bit(HAS_ALARM, &ds1307->flags);
1685 }
1686
1687 ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
1688 if (IS_ERR(ds1307->rtc))
1689 return PTR_ERR(ds1307->rtc);
1690
1691 if (ds1307_can_wakeup_device && !want_irq) {
1692 dev_info(ds1307->dev,
1693 "'wakeup-source' is set, request for an IRQ is disabled!\n");
1694 /* We cannot support UIE mode if we do not have an IRQ line */
1695 ds1307->rtc->uie_unsupported = 1;
1696 }
1697
1698 if (want_irq) {
1699 err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL,
1700 chip->irq_handler ?: ds1307_irq,
1701 IRQF_SHARED | IRQF_ONESHOT,
1702 ds1307->name, ds1307);
1703 if (err) {
1704 client->irq = 0;
1705 device_set_wakeup_capable(ds1307->dev, false);
1706 clear_bit(HAS_ALARM, &ds1307->flags);
1707 dev_err(ds1307->dev, "unable to request IRQ!\n");
1708 } else {
1709 dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
1710 }
1711 }
1712
1713 ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops;
1714 err = rtc_register_device(ds1307->rtc);
1715 if (err)
1716 return err;
1717
1718 if (chip->nvram_size) {
1719 struct nvmem_config nvmem_cfg = {
1720 .name = "ds1307_nvram",
1721 .word_size = 1,
1722 .stride = 1,
1723 .size = chip->nvram_size,
1724 .reg_read = ds1307_nvram_read,
1725 .reg_write = ds1307_nvram_write,
1726 .priv = ds1307,
1727 };
1728
1729 ds1307->rtc->nvram_old_abi = true;
1730 rtc_nvmem_register(ds1307->rtc, &nvmem_cfg);
1731 }
1732
1733 ds1307_hwmon_register(ds1307);
1734 ds1307_clks_register(ds1307);
1735
1736 return 0;
1737
1738 exit:
1739 return err;
1740 }
1741
1742 static struct i2c_driver ds1307_driver = {
1743 .driver = {
1744 .name = "rtc-ds1307",
1745 .of_match_table = of_match_ptr(ds1307_of_match),
1746 .acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
1747 },
1748 .probe = ds1307_probe,
1749 .id_table = ds1307_id,
1750 };
1751
1752 module_i2c_driver(ds1307_driver);
1753
1754 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1755 MODULE_LICENSE("GPL");
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