1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
4 *
5 * Copyright (C) 2005 James Chapman (ds1337 core)
6 * Copyright (C) 2006 David Brownell
7 * Copyright (C) 2009 Matthias Fuchs (rx8025 support)
8 * Copyright (C) 2012 Bertrand Achard (nvram access fixes)
9 */
10
11 #include <linux/bcd.h>
12 #include <linux/i2c.h>
13 #include <linux/init.h>
14 #include <linux/kstrtox.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/module.h>
17 #include <linux/property.h>
18 #include <linux/rtc/ds1307.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/clk-provider.h>
25 #include <linux/regmap.h>
26 #include <linux/watchdog.h>
27
28 /*
29 * We can't determine type by probing, but if we expect pre-Linux code
30 * to have set the chip up as a clock (turning on the oscillator and
31 * setting the date and time), Linux can ignore the non-clock features.
32 * That's a natural job for a factory or repair bench.
33 */
34 enum ds_type {
35 unknown_ds_type, /* always first and 0 */
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_OSCRUN BIT(5)
69 # define MCP794XX_BIT_VBATEN 0x08
70 #define DS1307_REG_MDAY 0x04 /* 01-31 */
71 #define DS1307_REG_MONTH 0x05 /* 01-12 */
72 # define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
73 #define DS1307_REG_YEAR 0x06 /* 00-99 */
74
75 /*
76 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
77 * start at 7, and they differ a LOT. Only control and status matter for
78 * basic RTC date and time functionality; be careful using them.
79 */
80 #define DS1307_REG_CONTROL 0x07 /* or ds1338 */
81 # define DS1307_BIT_OUT 0x80
82 # define DS1338_BIT_OSF 0x20
83 # define DS1307_BIT_SQWE 0x10
84 # define DS1307_BIT_RS1 0x02
85 # define DS1307_BIT_RS0 0x01
86 #define DS1337_REG_CONTROL 0x0e
87 # define DS1337_BIT_nEOSC 0x80
88 # define DS1339_BIT_BBSQI 0x20
89 # define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */
90 # define DS1337_BIT_RS2 0x10
91 # define DS1337_BIT_RS1 0x08
92 # define DS1337_BIT_INTCN 0x04
93 # define DS1337_BIT_A2IE 0x02
94 # define DS1337_BIT_A1IE 0x01
95 #define DS1340_REG_CONTROL 0x07
96 # define DS1340_BIT_OUT 0x80
97 # define DS1340_BIT_FT 0x40
98 # define DS1340_BIT_CALIB_SIGN 0x20
99 # define DS1340_M_CALIBRATION 0x1f
100 #define DS1340_REG_FLAG 0x09
101 # define DS1340_BIT_OSF 0x80
102 #define DS1337_REG_STATUS 0x0f
103 # define DS1337_BIT_OSF 0x80
104 # define DS3231_BIT_EN32KHZ 0x08
105 # define DS1337_BIT_A2I 0x02
106 # define DS1337_BIT_A1I 0x01
107 #define DS1339_REG_ALARM1_SECS 0x07
108
109 #define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0
110
111 #define RX8025_REG_CTRL1 0x0e
112 # define RX8025_BIT_2412 0x20
113 #define RX8025_REG_CTRL2 0x0f
114 # define RX8025_BIT_PON 0x10
115 # define RX8025_BIT_VDET 0x40
116 # define RX8025_BIT_XST 0x20
117
118 #define RX8130_REG_ALARM_MIN 0x17
119 #define RX8130_REG_ALARM_HOUR 0x18
120 #define RX8130_REG_ALARM_WEEK_OR_DAY 0x19
121 #define RX8130_REG_EXTENSION 0x1c
122 #define RX8130_REG_EXTENSION_WADA BIT(3)
123 #define RX8130_REG_FLAG 0x1d
124 #define RX8130_REG_FLAG_VLF BIT(1)
125 #define RX8130_REG_FLAG_AF BIT(3)
126 #define RX8130_REG_CONTROL0 0x1e
127 #define RX8130_REG_CONTROL0_AIE BIT(3)
128 #define RX8130_REG_CONTROL1 0x1f
129 #define RX8130_REG_CONTROL1_INIEN BIT(4)
130 #define RX8130_REG_CONTROL1_CHGEN BIT(5)
131
132 #define MCP794XX_REG_CONTROL 0x07
133 # define MCP794XX_BIT_ALM0_EN 0x10
134 # define MCP794XX_BIT_ALM1_EN 0x20
135 #define MCP794XX_REG_ALARM0_BASE 0x0a
136 #define MCP794XX_REG_ALARM0_CTRL 0x0d
137 #define MCP794XX_REG_ALARM1_BASE 0x11
138 #define MCP794XX_REG_ALARM1_CTRL 0x14
139 # define MCP794XX_BIT_ALMX_IF BIT(3)
140 # define MCP794XX_BIT_ALMX_C0 BIT(4)
141 # define MCP794XX_BIT_ALMX_C1 BIT(5)
142 # define MCP794XX_BIT_ALMX_C2 BIT(6)
143 # define MCP794XX_BIT_ALMX_POL BIT(7)
144 # define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
145 MCP794XX_BIT_ALMX_C1 | \
146 MCP794XX_BIT_ALMX_C2)
147
148 #define M41TXX_REG_CONTROL 0x07
149 # define M41TXX_BIT_OUT BIT(7)
150 # define M41TXX_BIT_FT BIT(6)
151 # define M41TXX_BIT_CALIB_SIGN BIT(5)
152 # define M41TXX_M_CALIBRATION GENMASK(4, 0)
153
154 #define DS1388_REG_WDOG_HUN_SECS 0x08
155 #define DS1388_REG_WDOG_SECS 0x09
156 #define DS1388_REG_FLAG 0x0b
157 # define DS1388_BIT_WF BIT(6)
158 # define DS1388_BIT_OSF BIT(7)
159 #define DS1388_REG_CONTROL 0x0c
160 # define DS1388_BIT_RST BIT(0)
161 # define DS1388_BIT_WDE BIT(1)
162 # define DS1388_BIT_nEOSC BIT(7)
163
164 /* negative offset step is -2.034ppm */
165 #define M41TXX_NEG_OFFSET_STEP_PPB 2034
166 /* positive offset step is +4.068ppm */
167 #define M41TXX_POS_OFFSET_STEP_PPB 4068
168 /* Min and max values supported with 'offset' interface by M41TXX */
169 #define M41TXX_MIN_OFFSET ((-31) * M41TXX_NEG_OFFSET_STEP_PPB)
170 #define M41TXX_MAX_OFFSET ((31) * M41TXX_POS_OFFSET_STEP_PPB)
171
172 struct ds1307 {
173 enum ds_type type;
174 struct device *dev;
175 struct regmap *regmap;
176 const char *name;
177 struct rtc_device *rtc;
178 #ifdef CONFIG_COMMON_CLK
179 struct clk_hw clks[2];
180 #endif
181 };
182
183 struct chip_desc {
184 unsigned alarm:1;
185 u16 nvram_offset;
186 u16 nvram_size;
187 u8 offset; /* register's offset */
188 u8 century_reg;
189 u8 century_enable_bit;
190 u8 century_bit;
191 u8 bbsqi_bit;
192 irq_handler_t irq_handler;
193 const struct rtc_class_ops *rtc_ops;
194 u16 trickle_charger_reg;
195 u8 (*do_trickle_setup)(struct ds1307 *, u32,
196 bool);
197 /* Does the RTC require trickle-resistor-ohms to select the value of
198 * the resistor between Vcc and Vbackup?
199 */
200 bool requires_trickle_resistor;
201 /* Some RTC's batteries and supercaps were charged by default, others
202 * allow charging but were not configured previously to do so.
203 * Remember this behavior to stay backwards compatible.
204 */
205 bool charge_default;
206 };
207
208 static const struct chip_desc chips[last_ds_type];
209
ds1307_get_time(struct device * dev,struct rtc_time * t)210 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
211 {
212 struct ds1307 *ds1307 = dev_get_drvdata(dev);
213 int tmp, ret;
214 const struct chip_desc *chip = &chips[ds1307->type];
215 u8 regs[7];
216
217 if (ds1307->type == rx_8130) {
218 unsigned int regflag;
219 ret = regmap_read(ds1307->regmap, RX8130_REG_FLAG, ®flag);
220 if (ret) {
221 dev_err(dev, "%s error %d\n", "read", ret);
222 return ret;
223 }
224
225 if (regflag & RX8130_REG_FLAG_VLF) {
226 dev_warn_once(dev, "oscillator failed, set time!\n");
227 return -EINVAL;
228 }
229 }
230
231 /* read the RTC date and time registers all at once */
232 ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
233 sizeof(regs));
234 if (ret) {
235 dev_err(dev, "%s error %d\n", "read", ret);
236 return ret;
237 }
238
239 dev_dbg(dev, "%s: %7ph\n", "read", regs);
240
241 /* if oscillator fail bit is set, no data can be trusted */
242 if (ds1307->type == m41t0 &&
243 regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
244 dev_warn_once(dev, "oscillator failed, set time!\n");
245 return -EINVAL;
246 } else if (ds1307->type == mcp794xx &&
247 !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_OSCRUN)) {
248 dev_warn_once(dev, "oscillator failed, set time!\n");
249 return -EINVAL;
250 }
251
252 tmp = regs[DS1307_REG_SECS];
253 switch (ds1307->type) {
254 case ds_1307:
255 case m41t0:
256 case m41t00:
257 case m41t11:
258 if (tmp & DS1307_BIT_CH)
259 return -EINVAL;
260 break;
261 case ds_1308:
262 case ds_1338:
263 if (tmp & DS1307_BIT_CH)
264 return -EINVAL;
265
266 ret = regmap_read(ds1307->regmap, DS1307_REG_CONTROL, &tmp);
267 if (ret)
268 return ret;
269 if (tmp & DS1338_BIT_OSF)
270 return -EINVAL;
271 break;
272 case ds_1340:
273 if (tmp & DS1340_BIT_nEOSC)
274 return -EINVAL;
275
276 ret = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp);
277 if (ret)
278 return ret;
279 if (tmp & DS1340_BIT_OSF)
280 return -EINVAL;
281 break;
282 case ds_1388:
283 ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &tmp);
284 if (ret)
285 return ret;
286 if (tmp & DS1388_BIT_OSF)
287 return -EINVAL;
288 break;
289 case mcp794xx:
290 if (!(tmp & MCP794XX_BIT_ST))
291 return -EINVAL;
292
293 break;
294 default:
295 break;
296 }
297
298 t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f);
299 t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
300 tmp = regs[DS1307_REG_HOUR] & 0x3f;
301 t->tm_hour = bcd2bin(tmp);
302 /* rx8130 is bit position, not BCD */
303 if (ds1307->type == rx_8130)
304 t->tm_wday = fls(regs[DS1307_REG_WDAY] & 0x7f);
305 else
306 t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
307 t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
308 tmp = regs[DS1307_REG_MONTH] & 0x1f;
309 t->tm_mon = bcd2bin(tmp) - 1;
310 t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
311
312 if (regs[chip->century_reg] & chip->century_bit &&
313 IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
314 t->tm_year += 100;
315
316 dev_dbg(dev, "%s secs=%d, mins=%d, "
317 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
318 "read", t->tm_sec, t->tm_min,
319 t->tm_hour, t->tm_mday,
320 t->tm_mon, t->tm_year, t->tm_wday);
321
322 return 0;
323 }
324
ds1307_set_time(struct device * dev,struct rtc_time * t)325 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
326 {
327 struct ds1307 *ds1307 = dev_get_drvdata(dev);
328 const struct chip_desc *chip = &chips[ds1307->type];
329 int result;
330 int tmp;
331 u8 regs[7];
332
333 dev_dbg(dev, "%s secs=%d, mins=%d, "
334 "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
335 "write", t->tm_sec, t->tm_min,
336 t->tm_hour, t->tm_mday,
337 t->tm_mon, t->tm_year, t->tm_wday);
338
339 if (t->tm_year < 100)
340 return -EINVAL;
341
342 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
343 if (t->tm_year > (chip->century_bit ? 299 : 199))
344 return -EINVAL;
345 #else
346 if (t->tm_year > 199)
347 return -EINVAL;
348 #endif
349
350 regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
351 regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
352 regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
353 /* rx8130 is bit position, not BCD */
354 if (ds1307->type == rx_8130)
355 regs[DS1307_REG_WDAY] = 1 << t->tm_wday;
356 else
357 regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
358 regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
359 regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
360
361 /* assume 20YY not 19YY */
362 tmp = t->tm_year % 100;
363 regs[DS1307_REG_YEAR] = bin2bcd(tmp);
364
365 if (chip->century_enable_bit)
366 regs[chip->century_reg] |= chip->century_enable_bit;
367 if (t->tm_year > 199 && chip->century_bit)
368 regs[chip->century_reg] |= chip->century_bit;
369
370 switch (ds1307->type) {
371 case ds_1308:
372 case ds_1338:
373 regmap_update_bits(ds1307->regmap, DS1307_REG_CONTROL,
374 DS1338_BIT_OSF, 0);
375 break;
376 case ds_1340:
377 regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG,
378 DS1340_BIT_OSF, 0);
379 break;
380 case ds_1388:
381 regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
382 DS1388_BIT_OSF, 0);
383 break;
384 case mcp794xx:
385 /*
386 * these bits were cleared when preparing the date/time
387 * values and need to be set again before writing the
388 * regsfer out to the device.
389 */
390 regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
391 regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
392 break;
393 default:
394 break;
395 }
396
397 dev_dbg(dev, "%s: %7ph\n", "write", regs);
398
399 result = regmap_bulk_write(ds1307->regmap, chip->offset, regs,
400 sizeof(regs));
401 if (result) {
402 dev_err(dev, "%s error %d\n", "write", result);
403 return result;
404 }
405
406 if (ds1307->type == rx_8130) {
407 /* clear Voltage Loss Flag as data is available now */
408 result = regmap_write(ds1307->regmap, RX8130_REG_FLAG,
409 ~(u8)RX8130_REG_FLAG_VLF);
410 if (result) {
411 dev_err(dev, "%s error %d\n", "write", result);
412 return result;
413 }
414 }
415
416 return 0;
417 }
418
ds1337_read_alarm(struct device * dev,struct rtc_wkalrm * t)419 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
420 {
421 struct ds1307 *ds1307 = dev_get_drvdata(dev);
422 int ret;
423 u8 regs[9];
424
425 /* read all ALARM1, ALARM2, and status registers at once */
426 ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
427 regs, sizeof(regs));
428 if (ret) {
429 dev_err(dev, "%s error %d\n", "alarm read", ret);
430 return ret;
431 }
432
433 dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
434 ®s[0], ®s[4], ®s[7]);
435
436 /*
437 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
438 * and that all four fields are checked matches
439 */
440 t->time.tm_sec = bcd2bin(regs[0] & 0x7f);
441 t->time.tm_min = bcd2bin(regs[1] & 0x7f);
442 t->time.tm_hour = bcd2bin(regs[2] & 0x3f);
443 t->time.tm_mday = bcd2bin(regs[3] & 0x3f);
444
445 /* ... and status */
446 t->enabled = !!(regs[7] & DS1337_BIT_A1IE);
447 t->pending = !!(regs[8] & DS1337_BIT_A1I);
448
449 dev_dbg(dev, "%s secs=%d, mins=%d, "
450 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
451 "alarm read", t->time.tm_sec, t->time.tm_min,
452 t->time.tm_hour, t->time.tm_mday,
453 t->enabled, t->pending);
454
455 return 0;
456 }
457
ds1337_set_alarm(struct device * dev,struct rtc_wkalrm * t)458 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
459 {
460 struct ds1307 *ds1307 = dev_get_drvdata(dev);
461 unsigned char regs[9];
462 u8 control, status;
463 int ret;
464
465 dev_dbg(dev, "%s secs=%d, mins=%d, "
466 "hours=%d, mday=%d, enabled=%d, pending=%d\n",
467 "alarm set", t->time.tm_sec, t->time.tm_min,
468 t->time.tm_hour, t->time.tm_mday,
469 t->enabled, t->pending);
470
471 /* read current status of both alarms and the chip */
472 ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
473 sizeof(regs));
474 if (ret) {
475 dev_err(dev, "%s error %d\n", "alarm write", ret);
476 return ret;
477 }
478 control = regs[7];
479 status = regs[8];
480
481 dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
482 ®s[0], ®s[4], control, status);
483
484 /* set ALARM1, using 24 hour and day-of-month modes */
485 regs[0] = bin2bcd(t->time.tm_sec);
486 regs[1] = bin2bcd(t->time.tm_min);
487 regs[2] = bin2bcd(t->time.tm_hour);
488 regs[3] = bin2bcd(t->time.tm_mday);
489
490 /* set ALARM2 to non-garbage */
491 regs[4] = 0;
492 regs[5] = 0;
493 regs[6] = 0;
494
495 /* disable alarms */
496 regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
497 regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
498
499 ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
500 sizeof(regs));
501 if (ret) {
502 dev_err(dev, "can't set alarm time\n");
503 return ret;
504 }
505
506 /* optionally enable ALARM1 */
507 if (t->enabled) {
508 dev_dbg(dev, "alarm IRQ armed\n");
509 regs[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
510 regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]);
511 }
512
513 return 0;
514 }
515
ds1307_alarm_irq_enable(struct device * dev,unsigned int enabled)516 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
517 {
518 struct ds1307 *ds1307 = dev_get_drvdata(dev);
519
520 return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
521 DS1337_BIT_A1IE,
522 enabled ? DS1337_BIT_A1IE : 0);
523 }
524
do_trickle_setup_ds1339(struct ds1307 * ds1307,u32 ohms,bool diode)525 static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode)
526 {
527 u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
528 DS1307_TRICKLE_CHARGER_NO_DIODE;
529
530 setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
531
532 switch (ohms) {
533 case 250:
534 setup |= DS1307_TRICKLE_CHARGER_250_OHM;
535 break;
536 case 2000:
537 setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
538 break;
539 case 4000:
540 setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
541 break;
542 default:
543 dev_warn(ds1307->dev,
544 "Unsupported ohm value %u in dt\n", ohms);
545 return 0;
546 }
547 return setup;
548 }
549
do_trickle_setup_rx8130(struct ds1307 * ds1307,u32 ohms,bool diode)550 static u8 do_trickle_setup_rx8130(struct ds1307 *ds1307, u32 ohms, bool diode)
551 {
552 /* make sure that the backup battery is enabled */
553 u8 setup = RX8130_REG_CONTROL1_INIEN;
554 if (diode)
555 setup |= RX8130_REG_CONTROL1_CHGEN;
556
557 return setup;
558 }
559
rx8130_irq(int irq,void * dev_id)560 static irqreturn_t rx8130_irq(int irq, void *dev_id)
561 {
562 struct ds1307 *ds1307 = dev_id;
563 u8 ctl[3];
564 int ret;
565
566 rtc_lock(ds1307->rtc);
567
568 /* Read control registers. */
569 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
570 sizeof(ctl));
571 if (ret < 0)
572 goto out;
573 if (!(ctl[1] & RX8130_REG_FLAG_AF))
574 goto out;
575 ctl[1] &= ~RX8130_REG_FLAG_AF;
576 ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
577
578 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
579 sizeof(ctl));
580 if (ret < 0)
581 goto out;
582
583 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
584
585 out:
586 rtc_unlock(ds1307->rtc);
587
588 return IRQ_HANDLED;
589 }
590
rx8130_read_alarm(struct device * dev,struct rtc_wkalrm * t)591 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t)
592 {
593 struct ds1307 *ds1307 = dev_get_drvdata(dev);
594 u8 ald[3], ctl[3];
595 int ret;
596
597 /* Read alarm registers. */
598 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
599 sizeof(ald));
600 if (ret < 0)
601 return ret;
602
603 /* Read control registers. */
604 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
605 sizeof(ctl));
606 if (ret < 0)
607 return ret;
608
609 t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE);
610 t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF);
611
612 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
613 t->time.tm_sec = -1;
614 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
615 t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
616 t->time.tm_wday = -1;
617 t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
618 t->time.tm_mon = -1;
619 t->time.tm_year = -1;
620 t->time.tm_yday = -1;
621 t->time.tm_isdst = -1;
622
623 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
624 __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
625 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
626
627 return 0;
628 }
629
rx8130_set_alarm(struct device * dev,struct rtc_wkalrm * t)630 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t)
631 {
632 struct ds1307 *ds1307 = dev_get_drvdata(dev);
633 u8 ald[3], ctl[3];
634 int ret;
635
636 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
637 "enabled=%d pending=%d\n", __func__,
638 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
639 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
640 t->enabled, t->pending);
641
642 /* Read control registers. */
643 ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
644 sizeof(ctl));
645 if (ret < 0)
646 return ret;
647
648 ctl[0] &= RX8130_REG_EXTENSION_WADA;
649 ctl[1] &= ~RX8130_REG_FLAG_AF;
650 ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
651
652 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
653 sizeof(ctl));
654 if (ret < 0)
655 return ret;
656
657 /* Hardware alarm precision is 1 minute! */
658 ald[0] = bin2bcd(t->time.tm_min);
659 ald[1] = bin2bcd(t->time.tm_hour);
660 ald[2] = bin2bcd(t->time.tm_mday);
661
662 ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
663 sizeof(ald));
664 if (ret < 0)
665 return ret;
666
667 if (!t->enabled)
668 return 0;
669
670 ctl[2] |= RX8130_REG_CONTROL0_AIE;
671
672 return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, ctl[2]);
673 }
674
rx8130_alarm_irq_enable(struct device * dev,unsigned int enabled)675 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled)
676 {
677 struct ds1307 *ds1307 = dev_get_drvdata(dev);
678 int ret, reg;
679
680 ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, ®);
681 if (ret < 0)
682 return ret;
683
684 if (enabled)
685 reg |= RX8130_REG_CONTROL0_AIE;
686 else
687 reg &= ~RX8130_REG_CONTROL0_AIE;
688
689 return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg);
690 }
691
mcp794xx_irq(int irq,void * dev_id)692 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
693 {
694 struct ds1307 *ds1307 = dev_id;
695 struct mutex *lock = &ds1307->rtc->ops_lock;
696 int reg, ret;
697
698 mutex_lock(lock);
699
700 /* Check and clear alarm 0 interrupt flag. */
701 ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, ®);
702 if (ret)
703 goto out;
704 if (!(reg & MCP794XX_BIT_ALMX_IF))
705 goto out;
706 reg &= ~MCP794XX_BIT_ALMX_IF;
707 ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg);
708 if (ret)
709 goto out;
710
711 /* Disable alarm 0. */
712 ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
713 MCP794XX_BIT_ALM0_EN, 0);
714 if (ret)
715 goto out;
716
717 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
718
719 out:
720 mutex_unlock(lock);
721
722 return IRQ_HANDLED;
723 }
724
mcp794xx_read_alarm(struct device * dev,struct rtc_wkalrm * t)725 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
726 {
727 struct ds1307 *ds1307 = dev_get_drvdata(dev);
728 u8 regs[10];
729 int ret;
730
731 /* Read control and alarm 0 registers. */
732 ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
733 sizeof(regs));
734 if (ret)
735 return ret;
736
737 t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
738
739 /* Report alarm 0 time assuming 24-hour and day-of-month modes. */
740 t->time.tm_sec = bcd2bin(regs[3] & 0x7f);
741 t->time.tm_min = bcd2bin(regs[4] & 0x7f);
742 t->time.tm_hour = bcd2bin(regs[5] & 0x3f);
743 t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1;
744 t->time.tm_mday = bcd2bin(regs[7] & 0x3f);
745 t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
746 t->time.tm_year = -1;
747 t->time.tm_yday = -1;
748 t->time.tm_isdst = -1;
749
750 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
751 "enabled=%d polarity=%d irq=%d match=%lu\n", __func__,
752 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
753 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
754 !!(regs[6] & MCP794XX_BIT_ALMX_POL),
755 !!(regs[6] & MCP794XX_BIT_ALMX_IF),
756 (regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
757
758 return 0;
759 }
760
761 /*
762 * We may have a random RTC weekday, therefore calculate alarm weekday based
763 * on current weekday we read from the RTC timekeeping regs
764 */
mcp794xx_alm_weekday(struct device * dev,struct rtc_time * tm_alarm)765 static int mcp794xx_alm_weekday(struct device *dev, struct rtc_time *tm_alarm)
766 {
767 struct rtc_time tm_now;
768 int days_now, days_alarm, ret;
769
770 ret = ds1307_get_time(dev, &tm_now);
771 if (ret)
772 return ret;
773
774 days_now = div_s64(rtc_tm_to_time64(&tm_now), 24 * 60 * 60);
775 days_alarm = div_s64(rtc_tm_to_time64(tm_alarm), 24 * 60 * 60);
776
777 return (tm_now.tm_wday + days_alarm - days_now) % 7 + 1;
778 }
779
mcp794xx_set_alarm(struct device * dev,struct rtc_wkalrm * t)780 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
781 {
782 struct ds1307 *ds1307 = dev_get_drvdata(dev);
783 unsigned char regs[10];
784 int wday, ret;
785
786 wday = mcp794xx_alm_weekday(dev, &t->time);
787 if (wday < 0)
788 return wday;
789
790 dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
791 "enabled=%d pending=%d\n", __func__,
792 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
793 t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
794 t->enabled, t->pending);
795
796 /* Read control and alarm 0 registers. */
797 ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
798 sizeof(regs));
799 if (ret)
800 return ret;
801
802 /* Set alarm 0, using 24-hour and day-of-month modes. */
803 regs[3] = bin2bcd(t->time.tm_sec);
804 regs[4] = bin2bcd(t->time.tm_min);
805 regs[5] = bin2bcd(t->time.tm_hour);
806 regs[6] = wday;
807 regs[7] = bin2bcd(t->time.tm_mday);
808 regs[8] = bin2bcd(t->time.tm_mon + 1);
809
810 /* Clear the alarm 0 interrupt flag. */
811 regs[6] &= ~MCP794XX_BIT_ALMX_IF;
812 /* Set alarm match: second, minute, hour, day, date, month. */
813 regs[6] |= MCP794XX_MSK_ALMX_MATCH;
814 /* Disable interrupt. We will not enable until completely programmed */
815 regs[0] &= ~MCP794XX_BIT_ALM0_EN;
816
817 ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
818 sizeof(regs));
819 if (ret)
820 return ret;
821
822 if (!t->enabled)
823 return 0;
824 regs[0] |= MCP794XX_BIT_ALM0_EN;
825 return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]);
826 }
827
mcp794xx_alarm_irq_enable(struct device * dev,unsigned int enabled)828 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
829 {
830 struct ds1307 *ds1307 = dev_get_drvdata(dev);
831
832 return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
833 MCP794XX_BIT_ALM0_EN,
834 enabled ? MCP794XX_BIT_ALM0_EN : 0);
835 }
836
m41txx_rtc_read_offset(struct device * dev,long * offset)837 static int m41txx_rtc_read_offset(struct device *dev, long *offset)
838 {
839 struct ds1307 *ds1307 = dev_get_drvdata(dev);
840 unsigned int ctrl_reg;
841 u8 val;
842
843 regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg);
844
845 val = ctrl_reg & M41TXX_M_CALIBRATION;
846
847 /* check if positive */
848 if (ctrl_reg & M41TXX_BIT_CALIB_SIGN)
849 *offset = (val * M41TXX_POS_OFFSET_STEP_PPB);
850 else
851 *offset = -(val * M41TXX_NEG_OFFSET_STEP_PPB);
852
853 return 0;
854 }
855
m41txx_rtc_set_offset(struct device * dev,long offset)856 static int m41txx_rtc_set_offset(struct device *dev, long offset)
857 {
858 struct ds1307 *ds1307 = dev_get_drvdata(dev);
859 unsigned int ctrl_reg;
860
861 if ((offset < M41TXX_MIN_OFFSET) || (offset > M41TXX_MAX_OFFSET))
862 return -ERANGE;
863
864 if (offset >= 0) {
865 ctrl_reg = DIV_ROUND_CLOSEST(offset,
866 M41TXX_POS_OFFSET_STEP_PPB);
867 ctrl_reg |= M41TXX_BIT_CALIB_SIGN;
868 } else {
869 ctrl_reg = DIV_ROUND_CLOSEST(abs(offset),
870 M41TXX_NEG_OFFSET_STEP_PPB);
871 }
872
873 return regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL,
874 M41TXX_M_CALIBRATION | M41TXX_BIT_CALIB_SIGN,
875 ctrl_reg);
876 }
877
878 #ifdef CONFIG_WATCHDOG_CORE
ds1388_wdt_start(struct watchdog_device * wdt_dev)879 static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
880 {
881 struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
882 u8 regs[2];
883 int ret;
884
885 ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
886 DS1388_BIT_WF, 0);
887 if (ret)
888 return ret;
889
890 ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
891 DS1388_BIT_WDE | DS1388_BIT_RST, 0);
892 if (ret)
893 return ret;
894
895 /*
896 * watchdog timeouts are measured in seconds. So ignore hundredths of
897 * seconds field.
898 */
899 regs[0] = 0;
900 regs[1] = bin2bcd(wdt_dev->timeout);
901
902 ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
903 sizeof(regs));
904 if (ret)
905 return ret;
906
907 return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
908 DS1388_BIT_WDE | DS1388_BIT_RST,
909 DS1388_BIT_WDE | DS1388_BIT_RST);
910 }
911
ds1388_wdt_stop(struct watchdog_device * wdt_dev)912 static int ds1388_wdt_stop(struct watchdog_device *wdt_dev)
913 {
914 struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
915
916 return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
917 DS1388_BIT_WDE | DS1388_BIT_RST, 0);
918 }
919
ds1388_wdt_ping(struct watchdog_device * wdt_dev)920 static int ds1388_wdt_ping(struct watchdog_device *wdt_dev)
921 {
922 struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
923 u8 regs[2];
924
925 return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
926 sizeof(regs));
927 }
928
ds1388_wdt_set_timeout(struct watchdog_device * wdt_dev,unsigned int val)929 static int ds1388_wdt_set_timeout(struct watchdog_device *wdt_dev,
930 unsigned int val)
931 {
932 struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
933 u8 regs[2];
934
935 wdt_dev->timeout = val;
936 regs[0] = 0;
937 regs[1] = bin2bcd(wdt_dev->timeout);
938
939 return regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
940 sizeof(regs));
941 }
942 #endif
943
944 static const struct rtc_class_ops rx8130_rtc_ops = {
945 .read_time = ds1307_get_time,
946 .set_time = ds1307_set_time,
947 .read_alarm = rx8130_read_alarm,
948 .set_alarm = rx8130_set_alarm,
949 .alarm_irq_enable = rx8130_alarm_irq_enable,
950 };
951
952 static const struct rtc_class_ops mcp794xx_rtc_ops = {
953 .read_time = ds1307_get_time,
954 .set_time = ds1307_set_time,
955 .read_alarm = mcp794xx_read_alarm,
956 .set_alarm = mcp794xx_set_alarm,
957 .alarm_irq_enable = mcp794xx_alarm_irq_enable,
958 };
959
960 static const struct rtc_class_ops m41txx_rtc_ops = {
961 .read_time = ds1307_get_time,
962 .set_time = ds1307_set_time,
963 .read_alarm = ds1337_read_alarm,
964 .set_alarm = ds1337_set_alarm,
965 .alarm_irq_enable = ds1307_alarm_irq_enable,
966 .read_offset = m41txx_rtc_read_offset,
967 .set_offset = m41txx_rtc_set_offset,
968 };
969
970 static const struct chip_desc chips[last_ds_type] = {
971 [ds_1307] = {
972 .nvram_offset = 8,
973 .nvram_size = 56,
974 },
975 [ds_1308] = {
976 .nvram_offset = 8,
977 .nvram_size = 56,
978 },
979 [ds_1337] = {
980 .alarm = 1,
981 .century_reg = DS1307_REG_MONTH,
982 .century_bit = DS1337_BIT_CENTURY,
983 },
984 [ds_1338] = {
985 .nvram_offset = 8,
986 .nvram_size = 56,
987 },
988 [ds_1339] = {
989 .alarm = 1,
990 .century_reg = DS1307_REG_MONTH,
991 .century_bit = DS1337_BIT_CENTURY,
992 .bbsqi_bit = DS1339_BIT_BBSQI,
993 .trickle_charger_reg = 0x10,
994 .do_trickle_setup = &do_trickle_setup_ds1339,
995 .requires_trickle_resistor = true,
996 .charge_default = true,
997 },
998 [ds_1340] = {
999 .century_reg = DS1307_REG_HOUR,
1000 .century_enable_bit = DS1340_BIT_CENTURY_EN,
1001 .century_bit = DS1340_BIT_CENTURY,
1002 .do_trickle_setup = &do_trickle_setup_ds1339,
1003 .trickle_charger_reg = 0x08,
1004 .requires_trickle_resistor = true,
1005 .charge_default = true,
1006 },
1007 [ds_1341] = {
1008 .century_reg = DS1307_REG_MONTH,
1009 .century_bit = DS1337_BIT_CENTURY,
1010 },
1011 [ds_1388] = {
1012 .offset = 1,
1013 .trickle_charger_reg = 0x0a,
1014 },
1015 [ds_3231] = {
1016 .alarm = 1,
1017 .century_reg = DS1307_REG_MONTH,
1018 .century_bit = DS1337_BIT_CENTURY,
1019 .bbsqi_bit = DS3231_BIT_BBSQW,
1020 },
1021 [rx_8130] = {
1022 .alarm = 1,
1023 /* this is battery backed SRAM */
1024 .nvram_offset = 0x20,
1025 .nvram_size = 4, /* 32bit (4 word x 8 bit) */
1026 .offset = 0x10,
1027 .irq_handler = rx8130_irq,
1028 .rtc_ops = &rx8130_rtc_ops,
1029 .trickle_charger_reg = RX8130_REG_CONTROL1,
1030 .do_trickle_setup = &do_trickle_setup_rx8130,
1031 },
1032 [m41t0] = {
1033 .rtc_ops = &m41txx_rtc_ops,
1034 },
1035 [m41t00] = {
1036 .rtc_ops = &m41txx_rtc_ops,
1037 },
1038 [m41t11] = {
1039 /* this is battery backed SRAM */
1040 .nvram_offset = 8,
1041 .nvram_size = 56,
1042 .rtc_ops = &m41txx_rtc_ops,
1043 },
1044 [mcp794xx] = {
1045 .alarm = 1,
1046 /* this is battery backed SRAM */
1047 .nvram_offset = 0x20,
1048 .nvram_size = 0x40,
1049 .irq_handler = mcp794xx_irq,
1050 .rtc_ops = &mcp794xx_rtc_ops,
1051 },
1052 };
1053
1054 static const struct i2c_device_id ds1307_id[] = {
1055 { "ds1307", ds_1307 },
1056 { "ds1308", ds_1308 },
1057 { "ds1337", ds_1337 },
1058 { "ds1338", ds_1338 },
1059 { "ds1339", ds_1339 },
1060 { "ds1388", ds_1388 },
1061 { "ds1340", ds_1340 },
1062 { "ds1341", ds_1341 },
1063 { "ds3231", ds_3231 },
1064 { "m41t0", m41t0 },
1065 { "m41t00", m41t00 },
1066 { "m41t11", m41t11 },
1067 { "mcp7940x", mcp794xx },
1068 { "mcp7941x", mcp794xx },
1069 { "pt7c4338", ds_1307 },
1070 { "rx8025", rx_8025 },
1071 { "isl12057", ds_1337 },
1072 { "rx8130", rx_8130 },
1073 { }
1074 };
1075 MODULE_DEVICE_TABLE(i2c, ds1307_id);
1076
1077 static const struct of_device_id ds1307_of_match[] = {
1078 {
1079 .compatible = "dallas,ds1307",
1080 .data = (void *)ds_1307
1081 },
1082 {
1083 .compatible = "dallas,ds1308",
1084 .data = (void *)ds_1308
1085 },
1086 {
1087 .compatible = "dallas,ds1337",
1088 .data = (void *)ds_1337
1089 },
1090 {
1091 .compatible = "dallas,ds1338",
1092 .data = (void *)ds_1338
1093 },
1094 {
1095 .compatible = "dallas,ds1339",
1096 .data = (void *)ds_1339
1097 },
1098 {
1099 .compatible = "dallas,ds1388",
1100 .data = (void *)ds_1388
1101 },
1102 {
1103 .compatible = "dallas,ds1340",
1104 .data = (void *)ds_1340
1105 },
1106 {
1107 .compatible = "dallas,ds1341",
1108 .data = (void *)ds_1341
1109 },
1110 {
1111 .compatible = "maxim,ds3231",
1112 .data = (void *)ds_3231
1113 },
1114 {
1115 .compatible = "st,m41t0",
1116 .data = (void *)m41t0
1117 },
1118 {
1119 .compatible = "st,m41t00",
1120 .data = (void *)m41t00
1121 },
1122 {
1123 .compatible = "st,m41t11",
1124 .data = (void *)m41t11
1125 },
1126 {
1127 .compatible = "microchip,mcp7940x",
1128 .data = (void *)mcp794xx
1129 },
1130 {
1131 .compatible = "microchip,mcp7941x",
1132 .data = (void *)mcp794xx
1133 },
1134 {
1135 .compatible = "pericom,pt7c4338",
1136 .data = (void *)ds_1307
1137 },
1138 {
1139 .compatible = "epson,rx8025",
1140 .data = (void *)rx_8025
1141 },
1142 {
1143 .compatible = "isil,isl12057",
1144 .data = (void *)ds_1337
1145 },
1146 {
1147 .compatible = "epson,rx8130",
1148 .data = (void *)rx_8130
1149 },
1150 { }
1151 };
1152 MODULE_DEVICE_TABLE(of, ds1307_of_match);
1153
1154 /*
1155 * The ds1337 and ds1339 both have two alarms, but we only use the first
1156 * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
1157 * signal; ds1339 chips have only one alarm signal.
1158 */
ds1307_irq(int irq,void * dev_id)1159 static irqreturn_t ds1307_irq(int irq, void *dev_id)
1160 {
1161 struct ds1307 *ds1307 = dev_id;
1162 struct mutex *lock = &ds1307->rtc->ops_lock;
1163 int stat, ret;
1164
1165 mutex_lock(lock);
1166 ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat);
1167 if (ret)
1168 goto out;
1169
1170 if (stat & DS1337_BIT_A1I) {
1171 stat &= ~DS1337_BIT_A1I;
1172 regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat);
1173
1174 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1175 DS1337_BIT_A1IE, 0);
1176 if (ret)
1177 goto out;
1178
1179 rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
1180 }
1181
1182 out:
1183 mutex_unlock(lock);
1184
1185 return IRQ_HANDLED;
1186 }
1187
1188 /*----------------------------------------------------------------------*/
1189
1190 static const struct rtc_class_ops ds13xx_rtc_ops = {
1191 .read_time = ds1307_get_time,
1192 .set_time = ds1307_set_time,
1193 .read_alarm = ds1337_read_alarm,
1194 .set_alarm = ds1337_set_alarm,
1195 .alarm_irq_enable = ds1307_alarm_irq_enable,
1196 };
1197
frequency_test_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1198 static ssize_t frequency_test_store(struct device *dev,
1199 struct device_attribute *attr,
1200 const char *buf, size_t count)
1201 {
1202 struct ds1307 *ds1307 = dev_get_drvdata(dev->parent);
1203 bool freq_test_en;
1204 int ret;
1205
1206 ret = kstrtobool(buf, &freq_test_en);
1207 if (ret) {
1208 dev_err(dev, "Failed to store RTC Frequency Test attribute\n");
1209 return ret;
1210 }
1211
1212 regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, M41TXX_BIT_FT,
1213 freq_test_en ? M41TXX_BIT_FT : 0);
1214
1215 return count;
1216 }
1217
frequency_test_show(struct device * dev,struct device_attribute * attr,char * buf)1218 static ssize_t frequency_test_show(struct device *dev,
1219 struct device_attribute *attr,
1220 char *buf)
1221 {
1222 struct ds1307 *ds1307 = dev_get_drvdata(dev->parent);
1223 unsigned int ctrl_reg;
1224
1225 regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg);
1226
1227 return sysfs_emit(buf, (ctrl_reg & M41TXX_BIT_FT) ? "on\n" : "off\n");
1228 }
1229
1230 static DEVICE_ATTR_RW(frequency_test);
1231
1232 static struct attribute *rtc_freq_test_attrs[] = {
1233 &dev_attr_frequency_test.attr,
1234 NULL,
1235 };
1236
1237 static const struct attribute_group rtc_freq_test_attr_group = {
1238 .attrs = rtc_freq_test_attrs,
1239 };
1240
ds1307_add_frequency_test(struct ds1307 * ds1307)1241 static int ds1307_add_frequency_test(struct ds1307 *ds1307)
1242 {
1243 int err;
1244
1245 switch (ds1307->type) {
1246 case m41t0:
1247 case m41t00:
1248 case m41t11:
1249 err = rtc_add_group(ds1307->rtc, &rtc_freq_test_attr_group);
1250 if (err)
1251 return err;
1252 break;
1253 default:
1254 break;
1255 }
1256
1257 return 0;
1258 }
1259
1260 /*----------------------------------------------------------------------*/
1261
ds1307_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)1262 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
1263 size_t bytes)
1264 {
1265 struct ds1307 *ds1307 = priv;
1266 const struct chip_desc *chip = &chips[ds1307->type];
1267
1268 return regmap_bulk_read(ds1307->regmap, chip->nvram_offset + offset,
1269 val, bytes);
1270 }
1271
ds1307_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)1272 static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
1273 size_t bytes)
1274 {
1275 struct ds1307 *ds1307 = priv;
1276 const struct chip_desc *chip = &chips[ds1307->type];
1277
1278 return regmap_bulk_write(ds1307->regmap, chip->nvram_offset + offset,
1279 val, bytes);
1280 }
1281
1282 /*----------------------------------------------------------------------*/
1283
ds1307_trickle_init(struct ds1307 * ds1307,const struct chip_desc * chip)1284 static u8 ds1307_trickle_init(struct ds1307 *ds1307,
1285 const struct chip_desc *chip)
1286 {
1287 u32 ohms, chargeable;
1288 bool diode = chip->charge_default;
1289
1290 if (!chip->do_trickle_setup)
1291 return 0;
1292
1293 if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
1294 &ohms) && chip->requires_trickle_resistor)
1295 return 0;
1296
1297 /* aux-voltage-chargeable takes precedence over the deprecated
1298 * trickle-diode-disable
1299 */
1300 if (!device_property_read_u32(ds1307->dev, "aux-voltage-chargeable",
1301 &chargeable)) {
1302 switch (chargeable) {
1303 case 0:
1304 diode = false;
1305 break;
1306 case 1:
1307 diode = true;
1308 break;
1309 default:
1310 dev_warn(ds1307->dev,
1311 "unsupported aux-voltage-chargeable value\n");
1312 break;
1313 }
1314 } else if (device_property_read_bool(ds1307->dev,
1315 "trickle-diode-disable")) {
1316 diode = false;
1317 }
1318
1319 return chip->do_trickle_setup(ds1307, ohms, diode);
1320 }
1321
1322 /*----------------------------------------------------------------------*/
1323
1324 #if IS_REACHABLE(CONFIG_HWMON)
1325
1326 /*
1327 * Temperature sensor support for ds3231 devices.
1328 */
1329
1330 #define DS3231_REG_TEMPERATURE 0x11
1331
1332 /*
1333 * A user-initiated temperature conversion is not started by this function,
1334 * so the temperature is updated once every 64 seconds.
1335 */
ds3231_hwmon_read_temp(struct device * dev,s32 * mC)1336 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
1337 {
1338 struct ds1307 *ds1307 = dev_get_drvdata(dev);
1339 u8 temp_buf[2];
1340 s16 temp;
1341 int ret;
1342
1343 ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE,
1344 temp_buf, sizeof(temp_buf));
1345 if (ret)
1346 return ret;
1347 /*
1348 * Temperature is represented as a 10-bit code with a resolution of
1349 * 0.25 degree celsius and encoded in two's complement format.
1350 */
1351 temp = (temp_buf[0] << 8) | temp_buf[1];
1352 temp >>= 6;
1353 *mC = temp * 250;
1354
1355 return 0;
1356 }
1357
ds3231_hwmon_show_temp(struct device * dev,struct device_attribute * attr,char * buf)1358 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
1359 struct device_attribute *attr, char *buf)
1360 {
1361 int ret;
1362 s32 temp;
1363
1364 ret = ds3231_hwmon_read_temp(dev, &temp);
1365 if (ret)
1366 return ret;
1367
1368 return sprintf(buf, "%d\n", temp);
1369 }
1370 static SENSOR_DEVICE_ATTR(temp1_input, 0444, ds3231_hwmon_show_temp,
1371 NULL, 0);
1372
1373 static struct attribute *ds3231_hwmon_attrs[] = {
1374 &sensor_dev_attr_temp1_input.dev_attr.attr,
1375 NULL,
1376 };
1377 ATTRIBUTE_GROUPS(ds3231_hwmon);
1378
ds1307_hwmon_register(struct ds1307 * ds1307)1379 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1380 {
1381 struct device *dev;
1382
1383 if (ds1307->type != ds_3231)
1384 return;
1385
1386 dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name,
1387 ds1307,
1388 ds3231_hwmon_groups);
1389 if (IS_ERR(dev)) {
1390 dev_warn(ds1307->dev, "unable to register hwmon device %ld\n",
1391 PTR_ERR(dev));
1392 }
1393 }
1394
1395 #else
1396
ds1307_hwmon_register(struct ds1307 * ds1307)1397 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1398 {
1399 }
1400
1401 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
1402
1403 /*----------------------------------------------------------------------*/
1404
1405 /*
1406 * Square-wave output support for DS3231
1407 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1408 */
1409 #ifdef CONFIG_COMMON_CLK
1410
1411 enum {
1412 DS3231_CLK_SQW = 0,
1413 DS3231_CLK_32KHZ,
1414 };
1415
1416 #define clk_sqw_to_ds1307(clk) \
1417 container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1418 #define clk_32khz_to_ds1307(clk) \
1419 container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1420
1421 static int ds3231_clk_sqw_rates[] = {
1422 1,
1423 1024,
1424 4096,
1425 8192,
1426 };
1427
ds1337_write_control(struct ds1307 * ds1307,u8 mask,u8 value)1428 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1429 {
1430 struct mutex *lock = &ds1307->rtc->ops_lock;
1431 int ret;
1432
1433 mutex_lock(lock);
1434 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1435 mask, value);
1436 mutex_unlock(lock);
1437
1438 return ret;
1439 }
1440
ds3231_clk_sqw_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1441 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1442 unsigned long parent_rate)
1443 {
1444 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1445 int control, ret;
1446 int rate_sel = 0;
1447
1448 ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1449 if (ret)
1450 return ret;
1451 if (control & DS1337_BIT_RS1)
1452 rate_sel += 1;
1453 if (control & DS1337_BIT_RS2)
1454 rate_sel += 2;
1455
1456 return ds3231_clk_sqw_rates[rate_sel];
1457 }
1458
ds3231_clk_sqw_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)1459 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1460 unsigned long *prate)
1461 {
1462 int i;
1463
1464 for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1465 if (ds3231_clk_sqw_rates[i] <= rate)
1466 return ds3231_clk_sqw_rates[i];
1467 }
1468
1469 return 0;
1470 }
1471
ds3231_clk_sqw_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)1472 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1473 unsigned long parent_rate)
1474 {
1475 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1476 int control = 0;
1477 int rate_sel;
1478
1479 for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1480 rate_sel++) {
1481 if (ds3231_clk_sqw_rates[rate_sel] == rate)
1482 break;
1483 }
1484
1485 if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1486 return -EINVAL;
1487
1488 if (rate_sel & 1)
1489 control |= DS1337_BIT_RS1;
1490 if (rate_sel & 2)
1491 control |= DS1337_BIT_RS2;
1492
1493 return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1494 control);
1495 }
1496
ds3231_clk_sqw_prepare(struct clk_hw * hw)1497 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1498 {
1499 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1500
1501 return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1502 }
1503
ds3231_clk_sqw_unprepare(struct clk_hw * hw)1504 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1505 {
1506 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1507
1508 ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1509 }
1510
ds3231_clk_sqw_is_prepared(struct clk_hw * hw)1511 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1512 {
1513 struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1514 int control, ret;
1515
1516 ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1517 if (ret)
1518 return ret;
1519
1520 return !(control & DS1337_BIT_INTCN);
1521 }
1522
1523 static const struct clk_ops ds3231_clk_sqw_ops = {
1524 .prepare = ds3231_clk_sqw_prepare,
1525 .unprepare = ds3231_clk_sqw_unprepare,
1526 .is_prepared = ds3231_clk_sqw_is_prepared,
1527 .recalc_rate = ds3231_clk_sqw_recalc_rate,
1528 .round_rate = ds3231_clk_sqw_round_rate,
1529 .set_rate = ds3231_clk_sqw_set_rate,
1530 };
1531
ds3231_clk_32khz_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1532 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1533 unsigned long parent_rate)
1534 {
1535 return 32768;
1536 }
1537
ds3231_clk_32khz_control(struct ds1307 * ds1307,bool enable)1538 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1539 {
1540 struct mutex *lock = &ds1307->rtc->ops_lock;
1541 int ret;
1542
1543 mutex_lock(lock);
1544 ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS,
1545 DS3231_BIT_EN32KHZ,
1546 enable ? DS3231_BIT_EN32KHZ : 0);
1547 mutex_unlock(lock);
1548
1549 return ret;
1550 }
1551
ds3231_clk_32khz_prepare(struct clk_hw * hw)1552 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1553 {
1554 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1555
1556 return ds3231_clk_32khz_control(ds1307, true);
1557 }
1558
ds3231_clk_32khz_unprepare(struct clk_hw * hw)1559 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1560 {
1561 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1562
1563 ds3231_clk_32khz_control(ds1307, false);
1564 }
1565
ds3231_clk_32khz_is_prepared(struct clk_hw * hw)1566 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1567 {
1568 struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1569 int status, ret;
1570
1571 ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status);
1572 if (ret)
1573 return ret;
1574
1575 return !!(status & DS3231_BIT_EN32KHZ);
1576 }
1577
1578 static const struct clk_ops ds3231_clk_32khz_ops = {
1579 .prepare = ds3231_clk_32khz_prepare,
1580 .unprepare = ds3231_clk_32khz_unprepare,
1581 .is_prepared = ds3231_clk_32khz_is_prepared,
1582 .recalc_rate = ds3231_clk_32khz_recalc_rate,
1583 };
1584
1585 static const char *ds3231_clks_names[] = {
1586 [DS3231_CLK_SQW] = "ds3231_clk_sqw",
1587 [DS3231_CLK_32KHZ] = "ds3231_clk_32khz",
1588 };
1589
1590 static struct clk_init_data ds3231_clks_init[] = {
1591 [DS3231_CLK_SQW] = {
1592 .ops = &ds3231_clk_sqw_ops,
1593 },
1594 [DS3231_CLK_32KHZ] = {
1595 .ops = &ds3231_clk_32khz_ops,
1596 },
1597 };
1598
ds3231_clks_register(struct ds1307 * ds1307)1599 static int ds3231_clks_register(struct ds1307 *ds1307)
1600 {
1601 struct device_node *node = ds1307->dev->of_node;
1602 struct clk_onecell_data *onecell;
1603 int i;
1604
1605 onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL);
1606 if (!onecell)
1607 return -ENOMEM;
1608
1609 onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1610 onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num,
1611 sizeof(onecell->clks[0]), GFP_KERNEL);
1612 if (!onecell->clks)
1613 return -ENOMEM;
1614
1615 /* optional override of the clockname */
1616 device_property_read_string_array(ds1307->dev, "clock-output-names",
1617 ds3231_clks_names,
1618 ARRAY_SIZE(ds3231_clks_names));
1619
1620 for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1621 struct clk_init_data init = ds3231_clks_init[i];
1622
1623 /*
1624 * Interrupt signal due to alarm conditions and square-wave
1625 * output share same pin, so don't initialize both.
1626 */
1627 if (i == DS3231_CLK_SQW && test_bit(RTC_FEATURE_ALARM, ds1307->rtc->features))
1628 continue;
1629
1630 init.name = ds3231_clks_names[i];
1631 ds1307->clks[i].init = &init;
1632
1633 onecell->clks[i] = devm_clk_register(ds1307->dev,
1634 &ds1307->clks[i]);
1635 if (IS_ERR(onecell->clks[i]))
1636 return PTR_ERR(onecell->clks[i]);
1637 }
1638
1639 if (node)
1640 of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1641
1642 return 0;
1643 }
1644
ds1307_clks_register(struct ds1307 * ds1307)1645 static void ds1307_clks_register(struct ds1307 *ds1307)
1646 {
1647 int ret;
1648
1649 if (ds1307->type != ds_3231)
1650 return;
1651
1652 ret = ds3231_clks_register(ds1307);
1653 if (ret) {
1654 dev_warn(ds1307->dev, "unable to register clock device %d\n",
1655 ret);
1656 }
1657 }
1658
1659 #else
1660
ds1307_clks_register(struct ds1307 * ds1307)1661 static void ds1307_clks_register(struct ds1307 *ds1307)
1662 {
1663 }
1664
1665 #endif /* CONFIG_COMMON_CLK */
1666
1667 #ifdef CONFIG_WATCHDOG_CORE
1668 static const struct watchdog_info ds1388_wdt_info = {
1669 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
1670 .identity = "DS1388 watchdog",
1671 };
1672
1673 static const struct watchdog_ops ds1388_wdt_ops = {
1674 .owner = THIS_MODULE,
1675 .start = ds1388_wdt_start,
1676 .stop = ds1388_wdt_stop,
1677 .ping = ds1388_wdt_ping,
1678 .set_timeout = ds1388_wdt_set_timeout,
1679
1680 };
1681
ds1307_wdt_register(struct ds1307 * ds1307)1682 static void ds1307_wdt_register(struct ds1307 *ds1307)
1683 {
1684 struct watchdog_device *wdt;
1685 int err;
1686 int val;
1687
1688 if (ds1307->type != ds_1388)
1689 return;
1690
1691 wdt = devm_kzalloc(ds1307->dev, sizeof(*wdt), GFP_KERNEL);
1692 if (!wdt)
1693 return;
1694
1695 err = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val);
1696 if (!err && val & DS1388_BIT_WF)
1697 wdt->bootstatus = WDIOF_CARDRESET;
1698
1699 wdt->info = &ds1388_wdt_info;
1700 wdt->ops = &ds1388_wdt_ops;
1701 wdt->timeout = 99;
1702 wdt->max_timeout = 99;
1703 wdt->min_timeout = 1;
1704
1705 watchdog_init_timeout(wdt, 0, ds1307->dev);
1706 watchdog_set_drvdata(wdt, ds1307);
1707 devm_watchdog_register_device(ds1307->dev, wdt);
1708 }
1709 #else
ds1307_wdt_register(struct ds1307 * ds1307)1710 static void ds1307_wdt_register(struct ds1307 *ds1307)
1711 {
1712 }
1713 #endif /* CONFIG_WATCHDOG_CORE */
1714
1715 static const struct regmap_config regmap_config = {
1716 .reg_bits = 8,
1717 .val_bits = 8,
1718 };
1719
ds1307_probe(struct i2c_client * client)1720 static int ds1307_probe(struct i2c_client *client)
1721 {
1722 const struct i2c_device_id *id = i2c_client_get_device_id(client);
1723 struct ds1307 *ds1307;
1724 const void *match;
1725 int err = -ENODEV;
1726 int tmp;
1727 const struct chip_desc *chip;
1728 bool want_irq;
1729 bool ds1307_can_wakeup_device = false;
1730 unsigned char regs[8];
1731 struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1732 u8 trickle_charger_setup = 0;
1733
1734 ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1735 if (!ds1307)
1736 return -ENOMEM;
1737
1738 dev_set_drvdata(&client->dev, ds1307);
1739 ds1307->dev = &client->dev;
1740 ds1307->name = client->name;
1741
1742 ds1307->regmap = devm_regmap_init_i2c(client, ®map_config);
1743 if (IS_ERR(ds1307->regmap)) {
1744 dev_err(ds1307->dev, "regmap allocation failed\n");
1745 return PTR_ERR(ds1307->regmap);
1746 }
1747
1748 i2c_set_clientdata(client, ds1307);
1749
1750 match = device_get_match_data(&client->dev);
1751 if (match) {
1752 ds1307->type = (uintptr_t)match;
1753 chip = &chips[ds1307->type];
1754 } else if (id) {
1755 chip = &chips[id->driver_data];
1756 ds1307->type = id->driver_data;
1757 } else {
1758 return -ENODEV;
1759 }
1760
1761 want_irq = client->irq > 0 && chip->alarm;
1762
1763 if (!pdata)
1764 trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
1765 else if (pdata->trickle_charger_setup)
1766 trickle_charger_setup = pdata->trickle_charger_setup;
1767
1768 if (trickle_charger_setup && chip->trickle_charger_reg) {
1769 dev_dbg(ds1307->dev,
1770 "writing trickle charger info 0x%x to 0x%x\n",
1771 trickle_charger_setup, chip->trickle_charger_reg);
1772 regmap_write(ds1307->regmap, chip->trickle_charger_reg,
1773 trickle_charger_setup);
1774 }
1775
1776 /*
1777 * For devices with no IRQ directly connected to the SoC, the RTC chip
1778 * can be forced as a wakeup source by stating that explicitly in
1779 * the device's .dts file using the "wakeup-source" boolean property.
1780 * If the "wakeup-source" property is set, don't request an IRQ.
1781 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1782 * if supported by the RTC.
1783 */
1784 if (chip->alarm && device_property_read_bool(&client->dev, "wakeup-source"))
1785 ds1307_can_wakeup_device = true;
1786
1787 switch (ds1307->type) {
1788 case ds_1337:
1789 case ds_1339:
1790 case ds_1341:
1791 case ds_3231:
1792 /* get registers that the "rtc" read below won't read... */
1793 err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
1794 regs, 2);
1795 if (err) {
1796 dev_dbg(ds1307->dev, "read error %d\n", err);
1797 goto exit;
1798 }
1799
1800 /* oscillator off? turn it on, so clock can tick. */
1801 if (regs[0] & DS1337_BIT_nEOSC)
1802 regs[0] &= ~DS1337_BIT_nEOSC;
1803
1804 /*
1805 * Using IRQ or defined as wakeup-source?
1806 * Disable the square wave and both alarms.
1807 * For some variants, be sure alarms can trigger when we're
1808 * running on Vbackup (BBSQI/BBSQW)
1809 */
1810 if (want_irq || ds1307_can_wakeup_device) {
1811 regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
1812 regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1813 }
1814
1815 regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
1816 regs[0]);
1817
1818 /* oscillator fault? clear flag, and warn */
1819 if (regs[1] & DS1337_BIT_OSF) {
1820 regmap_write(ds1307->regmap, DS1337_REG_STATUS,
1821 regs[1] & ~DS1337_BIT_OSF);
1822 dev_warn(ds1307->dev, "SET TIME!\n");
1823 }
1824 break;
1825
1826 case rx_8025:
1827 err = regmap_bulk_read(ds1307->regmap,
1828 RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
1829 if (err) {
1830 dev_dbg(ds1307->dev, "read error %d\n", err);
1831 goto exit;
1832 }
1833
1834 /* oscillator off? turn it on, so clock can tick. */
1835 if (!(regs[1] & RX8025_BIT_XST)) {
1836 regs[1] |= RX8025_BIT_XST;
1837 regmap_write(ds1307->regmap,
1838 RX8025_REG_CTRL2 << 4 | 0x08,
1839 regs[1]);
1840 dev_warn(ds1307->dev,
1841 "oscillator stop detected - SET TIME!\n");
1842 }
1843
1844 if (regs[1] & RX8025_BIT_PON) {
1845 regs[1] &= ~RX8025_BIT_PON;
1846 regmap_write(ds1307->regmap,
1847 RX8025_REG_CTRL2 << 4 | 0x08,
1848 regs[1]);
1849 dev_warn(ds1307->dev, "power-on detected\n");
1850 }
1851
1852 if (regs[1] & RX8025_BIT_VDET) {
1853 regs[1] &= ~RX8025_BIT_VDET;
1854 regmap_write(ds1307->regmap,
1855 RX8025_REG_CTRL2 << 4 | 0x08,
1856 regs[1]);
1857 dev_warn(ds1307->dev, "voltage drop detected\n");
1858 }
1859
1860 /* make sure we are running in 24hour mode */
1861 if (!(regs[0] & RX8025_BIT_2412)) {
1862 u8 hour;
1863
1864 /* switch to 24 hour mode */
1865 regmap_write(ds1307->regmap,
1866 RX8025_REG_CTRL1 << 4 | 0x08,
1867 regs[0] | RX8025_BIT_2412);
1868
1869 err = regmap_bulk_read(ds1307->regmap,
1870 RX8025_REG_CTRL1 << 4 | 0x08,
1871 regs, 2);
1872 if (err) {
1873 dev_dbg(ds1307->dev, "read error %d\n", err);
1874 goto exit;
1875 }
1876
1877 /* correct hour */
1878 hour = bcd2bin(regs[DS1307_REG_HOUR]);
1879 if (hour == 12)
1880 hour = 0;
1881 if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1882 hour += 12;
1883
1884 regmap_write(ds1307->regmap,
1885 DS1307_REG_HOUR << 4 | 0x08, hour);
1886 }
1887 break;
1888 case ds_1388:
1889 err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp);
1890 if (err) {
1891 dev_dbg(ds1307->dev, "read error %d\n", err);
1892 goto exit;
1893 }
1894
1895 /* oscillator off? turn it on, so clock can tick. */
1896 if (tmp & DS1388_BIT_nEOSC) {
1897 tmp &= ~DS1388_BIT_nEOSC;
1898 regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp);
1899 }
1900 break;
1901 default:
1902 break;
1903 }
1904
1905 /* read RTC registers */
1906 err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
1907 sizeof(regs));
1908 if (err) {
1909 dev_dbg(ds1307->dev, "read error %d\n", err);
1910 goto exit;
1911 }
1912
1913 if (ds1307->type == mcp794xx &&
1914 !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1915 regmap_write(ds1307->regmap, DS1307_REG_WDAY,
1916 regs[DS1307_REG_WDAY] |
1917 MCP794XX_BIT_VBATEN);
1918 }
1919
1920 tmp = regs[DS1307_REG_HOUR];
1921 switch (ds1307->type) {
1922 case ds_1340:
1923 case m41t0:
1924 case m41t00:
1925 case m41t11:
1926 /*
1927 * NOTE: ignores century bits; fix before deploying
1928 * systems that will run through year 2100.
1929 */
1930 break;
1931 case rx_8025:
1932 break;
1933 default:
1934 if (!(tmp & DS1307_BIT_12HR))
1935 break;
1936
1937 /*
1938 * Be sure we're in 24 hour mode. Multi-master systems
1939 * take note...
1940 */
1941 tmp = bcd2bin(tmp & 0x1f);
1942 if (tmp == 12)
1943 tmp = 0;
1944 if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1945 tmp += 12;
1946 regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
1947 bin2bcd(tmp));
1948 }
1949
1950 ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
1951 if (IS_ERR(ds1307->rtc))
1952 return PTR_ERR(ds1307->rtc);
1953
1954 if (want_irq || ds1307_can_wakeup_device)
1955 device_set_wakeup_capable(ds1307->dev, true);
1956 else
1957 clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features);
1958
1959 if (ds1307_can_wakeup_device && !want_irq) {
1960 dev_info(ds1307->dev,
1961 "'wakeup-source' is set, request for an IRQ is disabled!\n");
1962 /* We cannot support UIE mode if we do not have an IRQ line */
1963 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, ds1307->rtc->features);
1964 }
1965
1966 if (want_irq) {
1967 err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL,
1968 chip->irq_handler ?: ds1307_irq,
1969 IRQF_SHARED | IRQF_ONESHOT,
1970 ds1307->name, ds1307);
1971 if (err) {
1972 client->irq = 0;
1973 device_set_wakeup_capable(ds1307->dev, false);
1974 clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features);
1975 dev_err(ds1307->dev, "unable to request IRQ!\n");
1976 } else {
1977 dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
1978 }
1979 }
1980
1981 ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops;
1982 err = ds1307_add_frequency_test(ds1307);
1983 if (err)
1984 return err;
1985
1986 err = devm_rtc_register_device(ds1307->rtc);
1987 if (err)
1988 return err;
1989
1990 if (chip->nvram_size) {
1991 struct nvmem_config nvmem_cfg = {
1992 .name = "ds1307_nvram",
1993 .word_size = 1,
1994 .stride = 1,
1995 .size = chip->nvram_size,
1996 .reg_read = ds1307_nvram_read,
1997 .reg_write = ds1307_nvram_write,
1998 .priv = ds1307,
1999 };
2000
2001 devm_rtc_nvmem_register(ds1307->rtc, &nvmem_cfg);
2002 }
2003
2004 ds1307_hwmon_register(ds1307);
2005 ds1307_clks_register(ds1307);
2006 ds1307_wdt_register(ds1307);
2007
2008 return 0;
2009
2010 exit:
2011 return err;
2012 }
2013
2014 static struct i2c_driver ds1307_driver = {
2015 .driver = {
2016 .name = "rtc-ds1307",
2017 .of_match_table = ds1307_of_match,
2018 },
2019 .probe = ds1307_probe,
2020 .id_table = ds1307_id,
2021 };
2022
2023 module_i2c_driver(ds1307_driver);
2024
2025 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
2026 MODULE_LICENSE("GPL");
2027