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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An rtc driver for the Dallas/Maxim DS1685/DS1687 and related real-time
4 * chips.
5 *
6 * Copyright (C) 2011-2014 Joshua Kinard <[email protected]>.
7 * Copyright (C) 2009 Matthias Fuchs <[email protected]>.
8 *
9 * References:
10 * DS1685/DS1687 3V/5V Real-Time Clocks, 19-5215, Rev 4/10.
11 * DS17x85/DS17x87 3V/5V Real-Time Clocks, 19-5222, Rev 4/10.
12 * DS1689/DS1693 3V/5V Serialized Real-Time Clocks, Rev 112105.
13 * Application Note 90, Using the Multiplex Bus RTC Extended Features.
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/bcd.h>
19#include <linux/delay.h>
20#include <linux/io.h>
21#include <linux/module.h>
22#include <linux/platform_device.h>
23#include <linux/rtc.h>
24#include <linux/workqueue.h>
25
26#include <linux/rtc/ds1685.h>
27
28#ifdef CONFIG_PROC_FS
29#include <linux/proc_fs.h>
30#endif
31
32
33/* ----------------------------------------------------------------------- */
34/*
35 * Standard read/write
36 * all registers are mapped in CPU address space
37 */
38
39/**
40 * ds1685_read - read a value from an rtc register.
41 * @rtc: pointer to the ds1685 rtc structure.
42 * @reg: the register address to read.
43 */
44static u8
45ds1685_read(struct ds1685_priv *rtc, int reg)
46{
47 return readb((u8 __iomem *)rtc->regs +
48 (reg * rtc->regstep));
49}
50
51/**
52 * ds1685_write - write a value to an rtc register.
53 * @rtc: pointer to the ds1685 rtc structure.
54 * @reg: the register address to write.
55 * @value: value to write to the register.
56 */
57static void
58ds1685_write(struct ds1685_priv *rtc, int reg, u8 value)
59{
60 writeb(value, ((u8 __iomem *)rtc->regs +
61 (reg * rtc->regstep)));
62}
63/* ----------------------------------------------------------------------- */
64
65/*
66 * Indirect read/write functions
67 * access happens via address and data register mapped in CPU address space
68 */
69
70/**
71 * ds1685_indirect_read - read a value from an rtc register.
72 * @rtc: pointer to the ds1685 rtc structure.
73 * @reg: the register address to read.
74 */
75static u8
76ds1685_indirect_read(struct ds1685_priv *rtc, int reg)
77{
78 writeb(reg, rtc->regs);
79 return readb(rtc->data);
80}
81
82/**
83 * ds1685_indirect_write - write a value to an rtc register.
84 * @rtc: pointer to the ds1685 rtc structure.
85 * @reg: the register address to write.
86 * @value: value to write to the register.
87 */
88static void
89ds1685_indirect_write(struct ds1685_priv *rtc, int reg, u8 value)
90{
91 writeb(reg, rtc->regs);
92 writeb(value, rtc->data);
93}
94
95/* ----------------------------------------------------------------------- */
96/* Inlined functions */
97
98/**
99 * ds1685_rtc_bcd2bin - bcd2bin wrapper in case platform doesn't support BCD.
100 * @rtc: pointer to the ds1685 rtc structure.
101 * @val: u8 time value to consider converting.
102 * @bcd_mask: u8 mask value if BCD mode is used.
103 * @bin_mask: u8 mask value if BIN mode is used.
104 *
105 * Returns the value, converted to BIN if originally in BCD and bcd_mode TRUE.
106 */
107static inline u8
108ds1685_rtc_bcd2bin(struct ds1685_priv *rtc, u8 val, u8 bcd_mask, u8 bin_mask)
109{
110 if (rtc->bcd_mode)
111 return (bcd2bin(val) & bcd_mask);
112
113 return (val & bin_mask);
114}
115
116/**
117 * ds1685_rtc_bin2bcd - bin2bcd wrapper in case platform doesn't support BCD.
118 * @rtc: pointer to the ds1685 rtc structure.
119 * @val: u8 time value to consider converting.
120 * @bin_mask: u8 mask value if BIN mode is used.
121 * @bcd_mask: u8 mask value if BCD mode is used.
122 *
123 * Returns the value, converted to BCD if originally in BIN and bcd_mode TRUE.
124 */
125static inline u8
126ds1685_rtc_bin2bcd(struct ds1685_priv *rtc, u8 val, u8 bin_mask, u8 bcd_mask)
127{
128 if (rtc->bcd_mode)
129 return (bin2bcd(val) & bcd_mask);
130
131 return (val & bin_mask);
132}
133
134/**
135 * ds1685_rtc_check_mday - check validity of the day of month.
136 * @rtc: pointer to the ds1685 rtc structure.
137 * @mday: day of month.
138 *
139 * Returns -EDOM if the day of month is not within 1..31 range.
140 */
141static inline int
142ds1685_rtc_check_mday(struct ds1685_priv *rtc, u8 mday)
143{
144 if (rtc->bcd_mode) {
145 if (mday < 0x01 || mday > 0x31 || (mday & 0x0f) > 0x09)
146 return -EDOM;
147 } else {
148 if (mday < 1 || mday > 31)
149 return -EDOM;
150 }
151 return 0;
152}
153
154/**
155 * ds1685_rtc_switch_to_bank0 - switch the rtc to bank 0.
156 * @rtc: pointer to the ds1685 rtc structure.
157 */
158static inline void
159ds1685_rtc_switch_to_bank0(struct ds1685_priv *rtc)
160{
161 rtc->write(rtc, RTC_CTRL_A,
162 (rtc->read(rtc, RTC_CTRL_A) & ~(RTC_CTRL_A_DV0)));
163}
164
165/**
166 * ds1685_rtc_switch_to_bank1 - switch the rtc to bank 1.
167 * @rtc: pointer to the ds1685 rtc structure.
168 */
169static inline void
170ds1685_rtc_switch_to_bank1(struct ds1685_priv *rtc)
171{
172 rtc->write(rtc, RTC_CTRL_A,
173 (rtc->read(rtc, RTC_CTRL_A) | RTC_CTRL_A_DV0));
174}
175
176/**
177 * ds1685_rtc_begin_data_access - prepare the rtc for data access.
178 * @rtc: pointer to the ds1685 rtc structure.
179 *
180 * This takes several steps to prepare the rtc for access to get/set time
181 * and alarm values from the rtc registers:
182 * - Sets the SET bit in Control Register B.
183 * - Reads Ext Control Register 4A and checks the INCR bit.
184 * - If INCR is active, a short delay is added before Ext Control Register 4A
185 * is read again in a loop until INCR is inactive.
186 * - Switches the rtc to bank 1. This allows access to all relevant
187 * data for normal rtc operation, as bank 0 contains only the nvram.
188 */
189static inline void
190ds1685_rtc_begin_data_access(struct ds1685_priv *rtc)
191{
192 /* Set the SET bit in Ctrl B */
193 rtc->write(rtc, RTC_CTRL_B,
194 (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
195
196 /* Switch to Bank 1 */
197 ds1685_rtc_switch_to_bank1(rtc);
198
199 /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
200 while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
201 cpu_relax();
202}
203
204/**
205 * ds1685_rtc_end_data_access - end data access on the rtc.
206 * @rtc: pointer to the ds1685 rtc structure.
207 *
208 * This ends what was started by ds1685_rtc_begin_data_access:
209 * - Switches the rtc back to bank 0.
210 * - Clears the SET bit in Control Register B.
211 */
212static inline void
213ds1685_rtc_end_data_access(struct ds1685_priv *rtc)
214{
215 /* Switch back to Bank 0 */
216 ds1685_rtc_switch_to_bank0(rtc);
217
218 /* Clear the SET bit in Ctrl B */
219 rtc->write(rtc, RTC_CTRL_B,
220 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
221}
222
223/**
224 * ds1685_rtc_get_ssn - retrieve the silicon serial number.
225 * @rtc: pointer to the ds1685 rtc structure.
226 * @ssn: u8 array to hold the bits of the silicon serial number.
227 *
228 * This number starts at 0x40, and is 8-bytes long, ending at 0x47. The
229 * first byte is the model number, the next six bytes are the serial number
230 * digits, and the final byte is a CRC check byte. Together, they form the
231 * silicon serial number.
232 *
233 * These values are stored in bank1, so ds1685_rtc_switch_to_bank1 must be
234 * called first before calling this function, else data will be read out of
235 * the bank0 NVRAM. Be sure to call ds1685_rtc_switch_to_bank0 when done.
236 */
237static inline void
238ds1685_rtc_get_ssn(struct ds1685_priv *rtc, u8 *ssn)
239{
240 ssn[0] = rtc->read(rtc, RTC_BANK1_SSN_MODEL);
241 ssn[1] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_1);
242 ssn[2] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_2);
243 ssn[3] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_3);
244 ssn[4] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_4);
245 ssn[5] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_5);
246 ssn[6] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_6);
247 ssn[7] = rtc->read(rtc, RTC_BANK1_SSN_CRC);
248}
249/* ----------------------------------------------------------------------- */
250
251
252/* ----------------------------------------------------------------------- */
253/* Read/Set Time & Alarm functions */
254
255/**
256 * ds1685_rtc_read_time - reads the time registers.
257 * @dev: pointer to device structure.
258 * @tm: pointer to rtc_time structure.
259 */
260static int
261ds1685_rtc_read_time(struct device *dev, struct rtc_time *tm)
262{
263 struct ds1685_priv *rtc = dev_get_drvdata(dev);
264 u8 century;
265 u8 seconds, minutes, hours, wday, mday, month, years;
266
267 /* Fetch the time info from the RTC registers. */
268 ds1685_rtc_begin_data_access(rtc);
269 seconds = rtc->read(rtc, RTC_SECS);
270 minutes = rtc->read(rtc, RTC_MINS);
271 hours = rtc->read(rtc, RTC_HRS);
272 wday = rtc->read(rtc, RTC_WDAY);
273 mday = rtc->read(rtc, RTC_MDAY);
274 month = rtc->read(rtc, RTC_MONTH);
275 years = rtc->read(rtc, RTC_YEAR);
276 century = rtc->read(rtc, RTC_CENTURY);
277 ds1685_rtc_end_data_access(rtc);
278
279 /* bcd2bin if needed, perform fixups, and store to rtc_time. */
280 years = ds1685_rtc_bcd2bin(rtc, years, RTC_YEAR_BCD_MASK,
281 RTC_YEAR_BIN_MASK);
282 century = ds1685_rtc_bcd2bin(rtc, century, RTC_CENTURY_MASK,
283 RTC_CENTURY_MASK);
284 tm->tm_sec = ds1685_rtc_bcd2bin(rtc, seconds, RTC_SECS_BCD_MASK,
285 RTC_SECS_BIN_MASK);
286 tm->tm_min = ds1685_rtc_bcd2bin(rtc, minutes, RTC_MINS_BCD_MASK,
287 RTC_MINS_BIN_MASK);
288 tm->tm_hour = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_24_BCD_MASK,
289 RTC_HRS_24_BIN_MASK);
290 tm->tm_wday = (ds1685_rtc_bcd2bin(rtc, wday, RTC_WDAY_MASK,
291 RTC_WDAY_MASK) - 1);
292 tm->tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
293 RTC_MDAY_BIN_MASK);
294 tm->tm_mon = (ds1685_rtc_bcd2bin(rtc, month, RTC_MONTH_BCD_MASK,
295 RTC_MONTH_BIN_MASK) - 1);
296 tm->tm_year = ((years + (century * 100)) - 1900);
297 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
298 tm->tm_isdst = 0; /* RTC has hardcoded timezone, so don't use. */
299
300 return 0;
301}
302
303/**
304 * ds1685_rtc_set_time - sets the time registers.
305 * @dev: pointer to device structure.
306 * @tm: pointer to rtc_time structure.
307 */
308static int
309ds1685_rtc_set_time(struct device *dev, struct rtc_time *tm)
310{
311 struct ds1685_priv *rtc = dev_get_drvdata(dev);
312 u8 ctrlb, seconds, minutes, hours, wday, mday, month, years, century;
313
314 /* Fetch the time info from rtc_time. */
315 seconds = ds1685_rtc_bin2bcd(rtc, tm->tm_sec, RTC_SECS_BIN_MASK,
316 RTC_SECS_BCD_MASK);
317 minutes = ds1685_rtc_bin2bcd(rtc, tm->tm_min, RTC_MINS_BIN_MASK,
318 RTC_MINS_BCD_MASK);
319 hours = ds1685_rtc_bin2bcd(rtc, tm->tm_hour, RTC_HRS_24_BIN_MASK,
320 RTC_HRS_24_BCD_MASK);
321 wday = ds1685_rtc_bin2bcd(rtc, (tm->tm_wday + 1), RTC_WDAY_MASK,
322 RTC_WDAY_MASK);
323 mday = ds1685_rtc_bin2bcd(rtc, tm->tm_mday, RTC_MDAY_BIN_MASK,
324 RTC_MDAY_BCD_MASK);
325 month = ds1685_rtc_bin2bcd(rtc, (tm->tm_mon + 1), RTC_MONTH_BIN_MASK,
326 RTC_MONTH_BCD_MASK);
327 years = ds1685_rtc_bin2bcd(rtc, (tm->tm_year % 100),
328 RTC_YEAR_BIN_MASK, RTC_YEAR_BCD_MASK);
329 century = ds1685_rtc_bin2bcd(rtc, ((tm->tm_year + 1900) / 100),
330 RTC_CENTURY_MASK, RTC_CENTURY_MASK);
331
332 /*
333 * Perform Sanity Checks:
334 * - Months: !> 12, Month Day != 0.
335 * - Month Day !> Max days in current month.
336 * - Hours !>= 24, Mins !>= 60, Secs !>= 60, & Weekday !> 7.
337 */
338 if ((tm->tm_mon > 11) || (mday == 0))
339 return -EDOM;
340
341 if (tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year))
342 return -EDOM;
343
344 if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) ||
345 (tm->tm_sec >= 60) || (wday > 7))
346 return -EDOM;
347
348 /*
349 * Set the data mode to use and store the time values in the
350 * RTC registers.
351 */
352 ds1685_rtc_begin_data_access(rtc);
353 ctrlb = rtc->read(rtc, RTC_CTRL_B);
354 if (rtc->bcd_mode)
355 ctrlb &= ~(RTC_CTRL_B_DM);
356 else
357 ctrlb |= RTC_CTRL_B_DM;
358 rtc->write(rtc, RTC_CTRL_B, ctrlb);
359 rtc->write(rtc, RTC_SECS, seconds);
360 rtc->write(rtc, RTC_MINS, minutes);
361 rtc->write(rtc, RTC_HRS, hours);
362 rtc->write(rtc, RTC_WDAY, wday);
363 rtc->write(rtc, RTC_MDAY, mday);
364 rtc->write(rtc, RTC_MONTH, month);
365 rtc->write(rtc, RTC_YEAR, years);
366 rtc->write(rtc, RTC_CENTURY, century);
367 ds1685_rtc_end_data_access(rtc);
368
369 return 0;
370}
371
372/**
373 * ds1685_rtc_read_alarm - reads the alarm registers.
374 * @dev: pointer to device structure.
375 * @alrm: pointer to rtc_wkalrm structure.
376 *
377 * There are three primary alarm registers: seconds, minutes, and hours.
378 * A fourth alarm register for the month date is also available in bank1 for
379 * kickstart/wakeup features. The DS1685/DS1687 manual states that a
380 * "don't care" value ranging from 0xc0 to 0xff may be written into one or
381 * more of the three alarm bytes to act as a wildcard value. The fourth
382 * byte doesn't support a "don't care" value.
383 */
384static int
385ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
386{
387 struct ds1685_priv *rtc = dev_get_drvdata(dev);
388 u8 seconds, minutes, hours, mday, ctrlb, ctrlc;
389 int ret;
390
391 /* Fetch the alarm info from the RTC alarm registers. */
392 ds1685_rtc_begin_data_access(rtc);
393 seconds = rtc->read(rtc, RTC_SECS_ALARM);
394 minutes = rtc->read(rtc, RTC_MINS_ALARM);
395 hours = rtc->read(rtc, RTC_HRS_ALARM);
396 mday = rtc->read(rtc, RTC_MDAY_ALARM);
397 ctrlb = rtc->read(rtc, RTC_CTRL_B);
398 ctrlc = rtc->read(rtc, RTC_CTRL_C);
399 ds1685_rtc_end_data_access(rtc);
400
401 /* Check the month date for validity. */
402 ret = ds1685_rtc_check_mday(rtc, mday);
403 if (ret)
404 return ret;
405
406 /*
407 * Check the three alarm bytes.
408 *
409 * The Linux RTC system doesn't support the "don't care" capability
410 * of this RTC chip. We check for it anyways in case support is
411 * added in the future and only assign when we care.
412 */
413 if (likely(seconds < 0xc0))
414 alrm->time.tm_sec = ds1685_rtc_bcd2bin(rtc, seconds,
415 RTC_SECS_BCD_MASK,
416 RTC_SECS_BIN_MASK);
417
418 if (likely(minutes < 0xc0))
419 alrm->time.tm_min = ds1685_rtc_bcd2bin(rtc, minutes,
420 RTC_MINS_BCD_MASK,
421 RTC_MINS_BIN_MASK);
422
423 if (likely(hours < 0xc0))
424 alrm->time.tm_hour = ds1685_rtc_bcd2bin(rtc, hours,
425 RTC_HRS_24_BCD_MASK,
426 RTC_HRS_24_BIN_MASK);
427
428 /* Write the data to rtc_wkalrm. */
429 alrm->time.tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
430 RTC_MDAY_BIN_MASK);
431 alrm->enabled = !!(ctrlb & RTC_CTRL_B_AIE);
432 alrm->pending = !!(ctrlc & RTC_CTRL_C_AF);
433
434 return 0;
435}
436
437/**
438 * ds1685_rtc_set_alarm - sets the alarm in registers.
439 * @dev: pointer to device structure.
440 * @alrm: pointer to rtc_wkalrm structure.
441 */
442static int
443ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
444{
445 struct ds1685_priv *rtc = dev_get_drvdata(dev);
446 u8 ctrlb, seconds, minutes, hours, mday;
447 int ret;
448
449 /* Fetch the alarm info and convert to BCD. */
450 seconds = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_sec,
451 RTC_SECS_BIN_MASK,
452 RTC_SECS_BCD_MASK);
453 minutes = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_min,
454 RTC_MINS_BIN_MASK,
455 RTC_MINS_BCD_MASK);
456 hours = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_hour,
457 RTC_HRS_24_BIN_MASK,
458 RTC_HRS_24_BCD_MASK);
459 mday = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_mday,
460 RTC_MDAY_BIN_MASK,
461 RTC_MDAY_BCD_MASK);
462
463 /* Check the month date for validity. */
464 ret = ds1685_rtc_check_mday(rtc, mday);
465 if (ret)
466 return ret;
467
468 /*
469 * Check the three alarm bytes.
470 *
471 * The Linux RTC system doesn't support the "don't care" capability
472 * of this RTC chip because rtc_valid_tm tries to validate every
473 * field, and we only support four fields. We put the support
474 * here anyways for the future.
475 */
476 if (unlikely(seconds >= 0xc0))
477 seconds = 0xff;
478
479 if (unlikely(minutes >= 0xc0))
480 minutes = 0xff;
481
482 if (unlikely(hours >= 0xc0))
483 hours = 0xff;
484
485 alrm->time.tm_mon = -1;
486 alrm->time.tm_year = -1;
487 alrm->time.tm_wday = -1;
488 alrm->time.tm_yday = -1;
489 alrm->time.tm_isdst = -1;
490
491 /* Disable the alarm interrupt first. */
492 ds1685_rtc_begin_data_access(rtc);
493 ctrlb = rtc->read(rtc, RTC_CTRL_B);
494 rtc->write(rtc, RTC_CTRL_B, (ctrlb & ~(RTC_CTRL_B_AIE)));
495
496 /* Read ctrlc to clear RTC_CTRL_C_AF. */
497 rtc->read(rtc, RTC_CTRL_C);
498
499 /*
500 * Set the data mode to use and store the time values in the
501 * RTC registers.
502 */
503 ctrlb = rtc->read(rtc, RTC_CTRL_B);
504 if (rtc->bcd_mode)
505 ctrlb &= ~(RTC_CTRL_B_DM);
506 else
507 ctrlb |= RTC_CTRL_B_DM;
508 rtc->write(rtc, RTC_CTRL_B, ctrlb);
509 rtc->write(rtc, RTC_SECS_ALARM, seconds);
510 rtc->write(rtc, RTC_MINS_ALARM, minutes);
511 rtc->write(rtc, RTC_HRS_ALARM, hours);
512 rtc->write(rtc, RTC_MDAY_ALARM, mday);
513
514 /* Re-enable the alarm if needed. */
515 if (alrm->enabled) {
516 ctrlb = rtc->read(rtc, RTC_CTRL_B);
517 ctrlb |= RTC_CTRL_B_AIE;
518 rtc->write(rtc, RTC_CTRL_B, ctrlb);
519 }
520
521 /* Done! */
522 ds1685_rtc_end_data_access(rtc);
523
524 return 0;
525}
526/* ----------------------------------------------------------------------- */
527
528
529/* ----------------------------------------------------------------------- */
530/* /dev/rtcX Interface functions */
531
532/**
533 * ds1685_rtc_alarm_irq_enable - replaces ioctl() RTC_AIE on/off.
534 * @dev: pointer to device structure.
535 * @enabled: flag indicating whether to enable or disable.
536 */
537static int
538ds1685_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
539{
540 struct ds1685_priv *rtc = dev_get_drvdata(dev);
541
542 /* Flip the requisite interrupt-enable bit. */
543 if (enabled)
544 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) |
545 RTC_CTRL_B_AIE));
546 else
547 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) &
548 ~(RTC_CTRL_B_AIE)));
549
550 /* Read Control C to clear all the flag bits. */
551 rtc->read(rtc, RTC_CTRL_C);
552
553 return 0;
554}
555/* ----------------------------------------------------------------------- */
556
557
558/* ----------------------------------------------------------------------- */
559/* IRQ handler */
560
561/**
562 * ds1685_rtc_extended_irq - take care of extended interrupts
563 * @rtc: pointer to the ds1685 rtc structure.
564 * @pdev: platform device pointer.
565 */
566static void
567ds1685_rtc_extended_irq(struct ds1685_priv *rtc, struct platform_device *pdev)
568{
569 u8 ctrl4a, ctrl4b;
570
571 ds1685_rtc_switch_to_bank1(rtc);
572 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
573 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
574
575 /*
576 * Check for a kickstart interrupt. With Vcc applied, this
577 * typically means that the power button was pressed, so we
578 * begin the shutdown sequence.
579 */
580 if ((ctrl4b & RTC_CTRL_4B_KSE) && (ctrl4a & RTC_CTRL_4A_KF)) {
581 /* Briefly disable kickstarts to debounce button presses. */
582 rtc->write(rtc, RTC_EXT_CTRL_4B,
583 (rtc->read(rtc, RTC_EXT_CTRL_4B) &
584 ~(RTC_CTRL_4B_KSE)));
585
586 /* Clear the kickstart flag. */
587 rtc->write(rtc, RTC_EXT_CTRL_4A,
588 (ctrl4a & ~(RTC_CTRL_4A_KF)));
589
590
591 /*
592 * Sleep 500ms before re-enabling kickstarts. This allows
593 * adequate time to avoid reading signal jitter as additional
594 * button presses.
595 */
596 msleep(500);
597 rtc->write(rtc, RTC_EXT_CTRL_4B,
598 (rtc->read(rtc, RTC_EXT_CTRL_4B) |
599 RTC_CTRL_4B_KSE));
600
601 /* Call the platform pre-poweroff function. Else, shutdown. */
602 if (rtc->prepare_poweroff != NULL)
603 rtc->prepare_poweroff();
604 else
605 ds1685_rtc_poweroff(pdev);
606 }
607
608 /*
609 * Check for a wake-up interrupt. With Vcc applied, this is
610 * essentially a second alarm interrupt, except it takes into
611 * account the 'date' register in bank1 in addition to the
612 * standard three alarm registers.
613 */
614 if ((ctrl4b & RTC_CTRL_4B_WIE) && (ctrl4a & RTC_CTRL_4A_WF)) {
615 rtc->write(rtc, RTC_EXT_CTRL_4A,
616 (ctrl4a & ~(RTC_CTRL_4A_WF)));
617
618 /* Call the platform wake_alarm function if defined. */
619 if (rtc->wake_alarm != NULL)
620 rtc->wake_alarm();
621 else
622 dev_warn(&pdev->dev,
623 "Wake Alarm IRQ just occurred!\n");
624 }
625
626 /*
627 * Check for a ram-clear interrupt. This happens if RIE=1 and RF=0
628 * when RCE=1 in 4B. This clears all NVRAM bytes in bank0 by setting
629 * each byte to a logic 1. This has no effect on any extended
630 * NV-SRAM that might be present, nor on the time/calendar/alarm
631 * registers. After a ram-clear is completed, there is a minimum
632 * recovery time of ~150ms in which all reads/writes are locked out.
633 * NOTE: A ram-clear can still occur if RCE=1 and RIE=0. We cannot
634 * catch this scenario.
635 */
636 if ((ctrl4b & RTC_CTRL_4B_RIE) && (ctrl4a & RTC_CTRL_4A_RF)) {
637 rtc->write(rtc, RTC_EXT_CTRL_4A,
638 (ctrl4a & ~(RTC_CTRL_4A_RF)));
639 msleep(150);
640
641 /* Call the platform post_ram_clear function if defined. */
642 if (rtc->post_ram_clear != NULL)
643 rtc->post_ram_clear();
644 else
645 dev_warn(&pdev->dev,
646 "RAM-Clear IRQ just occurred!\n");
647 }
648 ds1685_rtc_switch_to_bank0(rtc);
649}
650
651/**
652 * ds1685_rtc_irq_handler - IRQ handler.
653 * @irq: IRQ number.
654 * @dev_id: platform device pointer.
655 */
656static irqreturn_t
657ds1685_rtc_irq_handler(int irq, void *dev_id)
658{
659 struct platform_device *pdev = dev_id;
660 struct ds1685_priv *rtc = platform_get_drvdata(pdev);
661 u8 ctrlb, ctrlc;
662 unsigned long events = 0;
663 u8 num_irqs = 0;
664
665 /* Abort early if the device isn't ready yet (i.e., DEBUG_SHIRQ). */
666 if (unlikely(!rtc))
667 return IRQ_HANDLED;
668
669 rtc_lock(rtc->dev);
670
671 /* Ctrlb holds the interrupt-enable bits and ctrlc the flag bits. */
672 ctrlb = rtc->read(rtc, RTC_CTRL_B);
673 ctrlc = rtc->read(rtc, RTC_CTRL_C);
674
675 /* Is the IRQF bit set? */
676 if (likely(ctrlc & RTC_CTRL_C_IRQF)) {
677 /*
678 * We need to determine if it was one of the standard
679 * events: PF, AF, or UF. If so, we handle them and
680 * update the RTC core.
681 */
682 if (likely(ctrlc & RTC_CTRL_B_PAU_MASK)) {
683 events = RTC_IRQF;
684
685 /* Check for a periodic interrupt. */
686 if ((ctrlb & RTC_CTRL_B_PIE) &&
687 (ctrlc & RTC_CTRL_C_PF)) {
688 events |= RTC_PF;
689 num_irqs++;
690 }
691
692 /* Check for an alarm interrupt. */
693 if ((ctrlb & RTC_CTRL_B_AIE) &&
694 (ctrlc & RTC_CTRL_C_AF)) {
695 events |= RTC_AF;
696 num_irqs++;
697 }
698
699 /* Check for an update interrupt. */
700 if ((ctrlb & RTC_CTRL_B_UIE) &&
701 (ctrlc & RTC_CTRL_C_UF)) {
702 events |= RTC_UF;
703 num_irqs++;
704 }
705 } else {
706 /*
707 * One of the "extended" interrupts was received that
708 * is not recognized by the RTC core.
709 */
710 ds1685_rtc_extended_irq(rtc, pdev);
711 }
712 }
713 rtc_update_irq(rtc->dev, num_irqs, events);
714 rtc_unlock(rtc->dev);
715
716 return events ? IRQ_HANDLED : IRQ_NONE;
717}
718/* ----------------------------------------------------------------------- */
719
720
721/* ----------------------------------------------------------------------- */
722/* ProcFS interface */
723
724#ifdef CONFIG_PROC_FS
725#define NUM_REGS 6 /* Num of control registers. */
726#define NUM_BITS 8 /* Num bits per register. */
727#define NUM_SPACES 4 /* Num spaces between each bit. */
728
729/*
730 * Periodic Interrupt Rates.
731 */
732static const char *ds1685_rtc_pirq_rate[16] = {
733 "none", "3.90625ms", "7.8125ms", "0.122070ms", "0.244141ms",
734 "0.488281ms", "0.9765625ms", "1.953125ms", "3.90625ms", "7.8125ms",
735 "15.625ms", "31.25ms", "62.5ms", "125ms", "250ms", "500ms"
736};
737
738/*
739 * Square-Wave Output Frequencies.
740 */
741static const char *ds1685_rtc_sqw_freq[16] = {
742 "none", "256Hz", "128Hz", "8192Hz", "4096Hz", "2048Hz", "1024Hz",
743 "512Hz", "256Hz", "128Hz", "64Hz", "32Hz", "16Hz", "8Hz", "4Hz", "2Hz"
744};
745
746/**
747 * ds1685_rtc_proc - procfs access function.
748 * @dev: pointer to device structure.
749 * @seq: pointer to seq_file structure.
750 */
751static int
752ds1685_rtc_proc(struct device *dev, struct seq_file *seq)
753{
754 struct ds1685_priv *rtc = dev_get_drvdata(dev);
755 u8 ctrla, ctrlb, ctrld, ctrl4a, ctrl4b, ssn[8];
756 char *model;
757
758 /* Read all the relevant data from the control registers. */
759 ds1685_rtc_switch_to_bank1(rtc);
760 ds1685_rtc_get_ssn(rtc, ssn);
761 ctrla = rtc->read(rtc, RTC_CTRL_A);
762 ctrlb = rtc->read(rtc, RTC_CTRL_B);
763 ctrld = rtc->read(rtc, RTC_CTRL_D);
764 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
765 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
766 ds1685_rtc_switch_to_bank0(rtc);
767
768 /* Determine the RTC model. */
769 switch (ssn[0]) {
770 case RTC_MODEL_DS1685:
771 model = "DS1685/DS1687\0";
772 break;
773 case RTC_MODEL_DS1689:
774 model = "DS1689/DS1693\0";
775 break;
776 case RTC_MODEL_DS17285:
777 model = "DS17285/DS17287\0";
778 break;
779 case RTC_MODEL_DS17485:
780 model = "DS17485/DS17487\0";
781 break;
782 case RTC_MODEL_DS17885:
783 model = "DS17885/DS17887\0";
784 break;
785 default:
786 model = "Unknown\0";
787 break;
788 }
789
790 /* Print out the information. */
791 seq_printf(seq,
792 "Model\t\t: %s\n"
793 "Oscillator\t: %s\n"
794 "12/24hr\t\t: %s\n"
795 "DST\t\t: %s\n"
796 "Data mode\t: %s\n"
797 "Battery\t\t: %s\n"
798 "Aux batt\t: %s\n"
799 "Update IRQ\t: %s\n"
800 "Periodic IRQ\t: %s\n"
801 "Periodic Rate\t: %s\n"
802 "SQW Freq\t: %s\n"
803 "Serial #\t: %8phC\n",
804 model,
805 ((ctrla & RTC_CTRL_A_DV1) ? "enabled" : "disabled"),
806 ((ctrlb & RTC_CTRL_B_2412) ? "24-hour" : "12-hour"),
807 ((ctrlb & RTC_CTRL_B_DSE) ? "enabled" : "disabled"),
808 ((ctrlb & RTC_CTRL_B_DM) ? "binary" : "BCD"),
809 ((ctrld & RTC_CTRL_D_VRT) ? "ok" : "exhausted or n/a"),
810 ((ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "exhausted or n/a"),
811 ((ctrlb & RTC_CTRL_B_UIE) ? "yes" : "no"),
812 ((ctrlb & RTC_CTRL_B_PIE) ? "yes" : "no"),
813 (!(ctrl4b & RTC_CTRL_4B_E32K) ?
814 ds1685_rtc_pirq_rate[(ctrla & RTC_CTRL_A_RS_MASK)] : "none"),
815 (!((ctrl4b & RTC_CTRL_4B_E32K)) ?
816 ds1685_rtc_sqw_freq[(ctrla & RTC_CTRL_A_RS_MASK)] : "32768Hz"),
817 ssn);
818 return 0;
819}
820#else
821#define ds1685_rtc_proc NULL
822#endif /* CONFIG_PROC_FS */
823/* ----------------------------------------------------------------------- */
824
825
826/* ----------------------------------------------------------------------- */
827/* RTC Class operations */
828
829static const struct rtc_class_ops
830ds1685_rtc_ops = {
831 .proc = ds1685_rtc_proc,
832 .read_time = ds1685_rtc_read_time,
833 .set_time = ds1685_rtc_set_time,
834 .read_alarm = ds1685_rtc_read_alarm,
835 .set_alarm = ds1685_rtc_set_alarm,
836 .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,
837};
838/* ----------------------------------------------------------------------- */
839
840static int ds1685_nvram_read(void *priv, unsigned int pos, void *val,
841 size_t size)
842{
843 struct ds1685_priv *rtc = priv;
844 struct mutex *rtc_mutex = &rtc->dev->ops_lock;
845 ssize_t count;
846 u8 *buf = val;
847 int err;
848
849 err = mutex_lock_interruptible(rtc_mutex);
850 if (err)
851 return err;
852
853 ds1685_rtc_switch_to_bank0(rtc);
854
855 /* Read NVRAM in time and bank0 registers. */
856 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
857 count++, size--) {
858 if (count < NVRAM_SZ_TIME)
859 *buf++ = rtc->read(rtc, (NVRAM_TIME_BASE + pos++));
860 else
861 *buf++ = rtc->read(rtc, (NVRAM_BANK0_BASE + pos++));
862 }
863
864#ifndef CONFIG_RTC_DRV_DS1689
865 if (size > 0) {
866 ds1685_rtc_switch_to_bank1(rtc);
867
868#ifndef CONFIG_RTC_DRV_DS1685
869 /* Enable burst-mode on DS17x85/DS17x87 */
870 rtc->write(rtc, RTC_EXT_CTRL_4A,
871 (rtc->read(rtc, RTC_EXT_CTRL_4A) |
872 RTC_CTRL_4A_BME));
873
874 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
875 * reading with burst-mode */
876 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
877 (pos - NVRAM_TOTAL_SZ_BANK0));
878#endif
879
880 /* Read NVRAM in bank1 registers. */
881 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
882 count++, size--) {
883#ifdef CONFIG_RTC_DRV_DS1685
884 /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
885 * before each read. */
886 rtc->write(rtc, RTC_BANK1_RAM_ADDR,
887 (pos - NVRAM_TOTAL_SZ_BANK0));
888#endif
889 *buf++ = rtc->read(rtc, RTC_BANK1_RAM_DATA_PORT);
890 pos++;
891 }
892
893#ifndef CONFIG_RTC_DRV_DS1685
894 /* Disable burst-mode on DS17x85/DS17x87 */
895 rtc->write(rtc, RTC_EXT_CTRL_4A,
896 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
897 ~(RTC_CTRL_4A_BME)));
898#endif
899 ds1685_rtc_switch_to_bank0(rtc);
900 }
901#endif /* !CONFIG_RTC_DRV_DS1689 */
902 mutex_unlock(rtc_mutex);
903
904 return 0;
905}
906
907static int ds1685_nvram_write(void *priv, unsigned int pos, void *val,
908 size_t size)
909{
910 struct ds1685_priv *rtc = priv;
911 struct mutex *rtc_mutex = &rtc->dev->ops_lock;
912 ssize_t count;
913 u8 *buf = val;
914 int err;
915
916 err = mutex_lock_interruptible(rtc_mutex);
917 if (err)
918 return err;
919
920 ds1685_rtc_switch_to_bank0(rtc);
921
922 /* Write NVRAM in time and bank0 registers. */
923 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
924 count++, size--)
925 if (count < NVRAM_SZ_TIME)
926 rtc->write(rtc, (NVRAM_TIME_BASE + pos++),
927 *buf++);
928 else
929 rtc->write(rtc, (NVRAM_BANK0_BASE), *buf++);
930
931#ifndef CONFIG_RTC_DRV_DS1689
932 if (size > 0) {
933 ds1685_rtc_switch_to_bank1(rtc);
934
935#ifndef CONFIG_RTC_DRV_DS1685
936 /* Enable burst-mode on DS17x85/DS17x87 */
937 rtc->write(rtc, RTC_EXT_CTRL_4A,
938 (rtc->read(rtc, RTC_EXT_CTRL_4A) |
939 RTC_CTRL_4A_BME));
940
941 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
942 * writing with burst-mode */
943 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
944 (pos - NVRAM_TOTAL_SZ_BANK0));
945#endif
946
947 /* Write NVRAM in bank1 registers. */
948 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
949 count++, size--) {
950#ifdef CONFIG_RTC_DRV_DS1685
951 /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
952 * before each read. */
953 rtc->write(rtc, RTC_BANK1_RAM_ADDR,
954 (pos - NVRAM_TOTAL_SZ_BANK0));
955#endif
956 rtc->write(rtc, RTC_BANK1_RAM_DATA_PORT, *buf++);
957 pos++;
958 }
959
960#ifndef CONFIG_RTC_DRV_DS1685
961 /* Disable burst-mode on DS17x85/DS17x87 */
962 rtc->write(rtc, RTC_EXT_CTRL_4A,
963 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
964 ~(RTC_CTRL_4A_BME)));
965#endif
966 ds1685_rtc_switch_to_bank0(rtc);
967 }
968#endif /* !CONFIG_RTC_DRV_DS1689 */
969 mutex_unlock(rtc_mutex);
970
971 return 0;
972}
973
974/* ----------------------------------------------------------------------- */
975/* SysFS interface */
976
977/**
978 * ds1685_rtc_sysfs_battery_show - sysfs file for main battery status.
979 * @dev: pointer to device structure.
980 * @attr: pointer to device_attribute structure.
981 * @buf: pointer to char array to hold the output.
982 */
983static ssize_t
984ds1685_rtc_sysfs_battery_show(struct device *dev,
985 struct device_attribute *attr, char *buf)
986{
987 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
988 u8 ctrld;
989
990 ctrld = rtc->read(rtc, RTC_CTRL_D);
991
992 return sprintf(buf, "%s\n",
993 (ctrld & RTC_CTRL_D_VRT) ? "ok" : "not ok or N/A");
994}
995static DEVICE_ATTR(battery, S_IRUGO, ds1685_rtc_sysfs_battery_show, NULL);
996
997/**
998 * ds1685_rtc_sysfs_auxbatt_show - sysfs file for aux battery status.
999 * @dev: pointer to device structure.
1000 * @attr: pointer to device_attribute structure.
1001 * @buf: pointer to char array to hold the output.
1002 */
1003static ssize_t
1004ds1685_rtc_sysfs_auxbatt_show(struct device *dev,
1005 struct device_attribute *attr, char *buf)
1006{
1007 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
1008 u8 ctrl4a;
1009
1010 ds1685_rtc_switch_to_bank1(rtc);
1011 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
1012 ds1685_rtc_switch_to_bank0(rtc);
1013
1014 return sprintf(buf, "%s\n",
1015 (ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "not ok or N/A");
1016}
1017static DEVICE_ATTR(auxbatt, S_IRUGO, ds1685_rtc_sysfs_auxbatt_show, NULL);
1018
1019/**
1020 * ds1685_rtc_sysfs_serial_show - sysfs file for silicon serial number.
1021 * @dev: pointer to device structure.
1022 * @attr: pointer to device_attribute structure.
1023 * @buf: pointer to char array to hold the output.
1024 */
1025static ssize_t
1026ds1685_rtc_sysfs_serial_show(struct device *dev,
1027 struct device_attribute *attr, char *buf)
1028{
1029 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
1030 u8 ssn[8];
1031
1032 ds1685_rtc_switch_to_bank1(rtc);
1033 ds1685_rtc_get_ssn(rtc, ssn);
1034 ds1685_rtc_switch_to_bank0(rtc);
1035
1036 return sprintf(buf, "%8phC\n", ssn);
1037}
1038static DEVICE_ATTR(serial, S_IRUGO, ds1685_rtc_sysfs_serial_show, NULL);
1039
1040/*
1041 * struct ds1685_rtc_sysfs_misc_attrs - list for misc RTC features.
1042 */
1043static struct attribute*
1044ds1685_rtc_sysfs_misc_attrs[] = {
1045 &dev_attr_battery.attr,
1046 &dev_attr_auxbatt.attr,
1047 &dev_attr_serial.attr,
1048 NULL,
1049};
1050
1051/*
1052 * struct ds1685_rtc_sysfs_misc_grp - attr group for misc RTC features.
1053 */
1054static const struct attribute_group
1055ds1685_rtc_sysfs_misc_grp = {
1056 .name = "misc",
1057 .attrs = ds1685_rtc_sysfs_misc_attrs,
1058};
1059
1060/* ----------------------------------------------------------------------- */
1061/* Driver Probe/Removal */
1062
1063/**
1064 * ds1685_rtc_probe - initializes rtc driver.
1065 * @pdev: pointer to platform_device structure.
1066 */
1067static int
1068ds1685_rtc_probe(struct platform_device *pdev)
1069{
1070 struct rtc_device *rtc_dev;
1071 struct ds1685_priv *rtc;
1072 struct ds1685_rtc_platform_data *pdata;
1073 u8 ctrla, ctrlb, hours;
1074 unsigned char am_pm;
1075 int ret = 0;
1076 struct nvmem_config nvmem_cfg = {
1077 .name = "ds1685_nvram",
1078 .size = NVRAM_TOTAL_SZ,
1079 .reg_read = ds1685_nvram_read,
1080 .reg_write = ds1685_nvram_write,
1081 };
1082
1083 /* Get the platform data. */
1084 pdata = (struct ds1685_rtc_platform_data *) pdev->dev.platform_data;
1085 if (!pdata)
1086 return -ENODEV;
1087
1088 /* Allocate memory for the rtc device. */
1089 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
1090 if (!rtc)
1091 return -ENOMEM;
1092
1093 /* Setup resources and access functions */
1094 switch (pdata->access_type) {
1095 case ds1685_reg_direct:
1096 rtc->regs = devm_platform_ioremap_resource(pdev, 0);
1097 if (IS_ERR(rtc->regs))
1098 return PTR_ERR(rtc->regs);
1099 rtc->read = ds1685_read;
1100 rtc->write = ds1685_write;
1101 break;
1102 case ds1685_reg_indirect:
1103 rtc->regs = devm_platform_ioremap_resource(pdev, 0);
1104 if (IS_ERR(rtc->regs))
1105 return PTR_ERR(rtc->regs);
1106 rtc->data = devm_platform_ioremap_resource(pdev, 1);
1107 if (IS_ERR(rtc->data))
1108 return PTR_ERR(rtc->data);
1109 rtc->read = ds1685_indirect_read;
1110 rtc->write = ds1685_indirect_write;
1111 break;
1112 }
1113
1114 if (!rtc->read || !rtc->write)
1115 return -ENXIO;
1116
1117 /* Get the register step size. */
1118 if (pdata->regstep > 0)
1119 rtc->regstep = pdata->regstep;
1120 else
1121 rtc->regstep = 1;
1122
1123 /* Platform pre-shutdown function, if defined. */
1124 if (pdata->plat_prepare_poweroff)
1125 rtc->prepare_poweroff = pdata->plat_prepare_poweroff;
1126
1127 /* Platform wake_alarm function, if defined. */
1128 if (pdata->plat_wake_alarm)
1129 rtc->wake_alarm = pdata->plat_wake_alarm;
1130
1131 /* Platform post_ram_clear function, if defined. */
1132 if (pdata->plat_post_ram_clear)
1133 rtc->post_ram_clear = pdata->plat_post_ram_clear;
1134
1135 /* set the driver data. */
1136 platform_set_drvdata(pdev, rtc);
1137
1138 /* Turn the oscillator on if is not already on (DV1 = 1). */
1139 ctrla = rtc->read(rtc, RTC_CTRL_A);
1140 if (!(ctrla & RTC_CTRL_A_DV1))
1141 ctrla |= RTC_CTRL_A_DV1;
1142
1143 /* Enable the countdown chain (DV2 = 0) */
1144 ctrla &= ~(RTC_CTRL_A_DV2);
1145
1146 /* Clear RS3-RS0 in Control A. */
1147 ctrla &= ~(RTC_CTRL_A_RS_MASK);
1148
1149 /*
1150 * All done with Control A. Switch to Bank 1 for the remainder of
1151 * the RTC setup so we have access to the extended functions.
1152 */
1153 ctrla |= RTC_CTRL_A_DV0;
1154 rtc->write(rtc, RTC_CTRL_A, ctrla);
1155
1156 /* Default to 32768kHz output. */
1157 rtc->write(rtc, RTC_EXT_CTRL_4B,
1158 (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_E32K));
1159
1160 /* Set the SET bit in Control B so we can do some housekeeping. */
1161 rtc->write(rtc, RTC_CTRL_B,
1162 (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
1163
1164 /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
1165 while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
1166 cpu_relax();
1167
1168 /*
1169 * If the platform supports BCD mode, then set DM=0 in Control B.
1170 * Otherwise, set DM=1 for BIN mode.
1171 */
1172 ctrlb = rtc->read(rtc, RTC_CTRL_B);
1173 if (pdata->bcd_mode)
1174 ctrlb &= ~(RTC_CTRL_B_DM);
1175 else
1176 ctrlb |= RTC_CTRL_B_DM;
1177 rtc->bcd_mode = pdata->bcd_mode;
1178
1179 /*
1180 * Disable Daylight Savings Time (DSE = 0).
1181 * The RTC has hardcoded timezone information that is rendered
1182 * obselete. We'll let the OS deal with DST settings instead.
1183 */
1184 if (ctrlb & RTC_CTRL_B_DSE)
1185 ctrlb &= ~(RTC_CTRL_B_DSE);
1186
1187 /* Force 24-hour mode (2412 = 1). */
1188 if (!(ctrlb & RTC_CTRL_B_2412)) {
1189 /* Reinitialize the time hours. */
1190 hours = rtc->read(rtc, RTC_HRS);
1191 am_pm = hours & RTC_HRS_AMPM_MASK;
1192 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1193 RTC_HRS_12_BIN_MASK);
1194 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1195
1196 /* Enable 24-hour mode. */
1197 ctrlb |= RTC_CTRL_B_2412;
1198
1199 /* Write back to Control B, including DM & DSE bits. */
1200 rtc->write(rtc, RTC_CTRL_B, ctrlb);
1201
1202 /* Write the time hours back. */
1203 rtc->write(rtc, RTC_HRS,
1204 ds1685_rtc_bin2bcd(rtc, hours,
1205 RTC_HRS_24_BIN_MASK,
1206 RTC_HRS_24_BCD_MASK));
1207
1208 /* Reinitialize the alarm hours. */
1209 hours = rtc->read(rtc, RTC_HRS_ALARM);
1210 am_pm = hours & RTC_HRS_AMPM_MASK;
1211 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1212 RTC_HRS_12_BIN_MASK);
1213 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1214
1215 /* Write the alarm hours back. */
1216 rtc->write(rtc, RTC_HRS_ALARM,
1217 ds1685_rtc_bin2bcd(rtc, hours,
1218 RTC_HRS_24_BIN_MASK,
1219 RTC_HRS_24_BCD_MASK));
1220 } else {
1221 /* 24-hour mode is already set, so write Control B back. */
1222 rtc->write(rtc, RTC_CTRL_B, ctrlb);
1223 }
1224
1225 /* Unset the SET bit in Control B so the RTC can update. */
1226 rtc->write(rtc, RTC_CTRL_B,
1227 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
1228
1229 /* Check the main battery. */
1230 if (!(rtc->read(rtc, RTC_CTRL_D) & RTC_CTRL_D_VRT))
1231 dev_warn(&pdev->dev,
1232 "Main battery is exhausted! RTC may be invalid!\n");
1233
1234 /* Check the auxillary battery. It is optional. */
1235 if (!(rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_VRT2))
1236 dev_warn(&pdev->dev,
1237 "Aux battery is exhausted or not available.\n");
1238
1239 /* Read Ctrl B and clear PIE/AIE/UIE. */
1240 rtc->write(rtc, RTC_CTRL_B,
1241 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_PAU_MASK)));
1242
1243 /* Reading Ctrl C auto-clears PF/AF/UF. */
1244 rtc->read(rtc, RTC_CTRL_C);
1245
1246 /* Read Ctrl 4B and clear RIE/WIE/KSE. */
1247 rtc->write(rtc, RTC_EXT_CTRL_4B,
1248 (rtc->read(rtc, RTC_EXT_CTRL_4B) & ~(RTC_CTRL_4B_RWK_MASK)));
1249
1250 /* Clear RF/WF/KF in Ctrl 4A. */
1251 rtc->write(rtc, RTC_EXT_CTRL_4A,
1252 (rtc->read(rtc, RTC_EXT_CTRL_4A) & ~(RTC_CTRL_4A_RWK_MASK)));
1253
1254 /*
1255 * Re-enable KSE to handle power button events. We do not enable
1256 * WIE or RIE by default.
1257 */
1258 rtc->write(rtc, RTC_EXT_CTRL_4B,
1259 (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_KSE));
1260
1261 rtc_dev = devm_rtc_allocate_device(&pdev->dev);
1262 if (IS_ERR(rtc_dev))
1263 return PTR_ERR(rtc_dev);
1264
1265 rtc_dev->ops = &ds1685_rtc_ops;
1266
1267 /* Century bit is useless because leap year fails in 1900 and 2100 */
1268 rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
1269 rtc_dev->range_max = RTC_TIMESTAMP_END_2099;
1270
1271 /* See if the platform doesn't support UIE. */
1272 if (pdata->uie_unsupported)
1273 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc_dev->features);
1274
1275 rtc->dev = rtc_dev;
1276
1277 /*
1278 * Fetch the IRQ and setup the interrupt handler.
1279 *
1280 * Not all platforms have the IRQF pin tied to something. If not, the
1281 * RTC will still set the *IE / *F flags and raise IRQF in ctrlc, but
1282 * there won't be an automatic way of notifying the kernel about it,
1283 * unless ctrlc is explicitly polled.
1284 */
1285 rtc->irq_num = platform_get_irq(pdev, 0);
1286 if (rtc->irq_num <= 0) {
1287 clear_bit(RTC_FEATURE_ALARM, rtc_dev->features);
1288 } else {
1289 /* Request an IRQ. */
1290 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq_num,
1291 NULL, ds1685_rtc_irq_handler,
1292 IRQF_SHARED | IRQF_ONESHOT,
1293 pdev->name, pdev);
1294
1295 /* Check to see if something came back. */
1296 if (unlikely(ret)) {
1297 dev_warn(&pdev->dev,
1298 "RTC interrupt not available\n");
1299 rtc->irq_num = 0;
1300 }
1301 }
1302
1303 /* Setup complete. */
1304 ds1685_rtc_switch_to_bank0(rtc);
1305
1306 ret = rtc_add_group(rtc_dev, &ds1685_rtc_sysfs_misc_grp);
1307 if (ret)
1308 return ret;
1309
1310 nvmem_cfg.priv = rtc;
1311 ret = devm_rtc_nvmem_register(rtc_dev, &nvmem_cfg);
1312 if (ret)
1313 return ret;
1314
1315 return devm_rtc_register_device(rtc_dev);
1316}
1317
1318/**
1319 * ds1685_rtc_remove - removes rtc driver.
1320 * @pdev: pointer to platform_device structure.
1321 */
1322static void
1323ds1685_rtc_remove(struct platform_device *pdev)
1324{
1325 struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1326
1327 /* Read Ctrl B and clear PIE/AIE/UIE. */
1328 rtc->write(rtc, RTC_CTRL_B,
1329 (rtc->read(rtc, RTC_CTRL_B) &
1330 ~(RTC_CTRL_B_PAU_MASK)));
1331
1332 /* Reading Ctrl C auto-clears PF/AF/UF. */
1333 rtc->read(rtc, RTC_CTRL_C);
1334
1335 /* Read Ctrl 4B and clear RIE/WIE/KSE. */
1336 rtc->write(rtc, RTC_EXT_CTRL_4B,
1337 (rtc->read(rtc, RTC_EXT_CTRL_4B) &
1338 ~(RTC_CTRL_4B_RWK_MASK)));
1339
1340 /* Manually clear RF/WF/KF in Ctrl 4A. */
1341 rtc->write(rtc, RTC_EXT_CTRL_4A,
1342 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
1343 ~(RTC_CTRL_4A_RWK_MASK)));
1344}
1345
1346/*
1347 * ds1685_rtc_driver - rtc driver properties.
1348 */
1349static struct platform_driver ds1685_rtc_driver = {
1350 .driver = {
1351 .name = "rtc-ds1685",
1352 },
1353 .probe = ds1685_rtc_probe,
1354 .remove = ds1685_rtc_remove,
1355};
1356module_platform_driver(ds1685_rtc_driver);
1357/* ----------------------------------------------------------------------- */
1358
1359
1360/* ----------------------------------------------------------------------- */
1361/* Poweroff function */
1362
1363/**
1364 * ds1685_rtc_poweroff - uses the RTC chip to power the system off.
1365 * @pdev: pointer to platform_device structure.
1366 */
1367void __noreturn
1368ds1685_rtc_poweroff(struct platform_device *pdev)
1369{
1370 u8 ctrla, ctrl4a, ctrl4b;
1371 struct ds1685_priv *rtc;
1372
1373 /* Check for valid RTC data, else, spin forever. */
1374 if (unlikely(!pdev)) {
1375 pr_emerg("platform device data not available, spinning forever ...\n");
1376 while(1);
1377 unreachable();
1378 } else {
1379 /* Get the rtc data. */
1380 rtc = platform_get_drvdata(pdev);
1381
1382 /*
1383 * Disable our IRQ. We're powering down, so we're not
1384 * going to worry about cleaning up. Most of that should
1385 * have been taken care of by the shutdown scripts and this
1386 * is the final function call.
1387 */
1388 if (rtc->irq_num)
1389 disable_irq_nosync(rtc->irq_num);
1390
1391 /* Oscillator must be on and the countdown chain enabled. */
1392 ctrla = rtc->read(rtc, RTC_CTRL_A);
1393 ctrla |= RTC_CTRL_A_DV1;
1394 ctrla &= ~(RTC_CTRL_A_DV2);
1395 rtc->write(rtc, RTC_CTRL_A, ctrla);
1396
1397 /*
1398 * Read Control 4A and check the status of the auxillary
1399 * battery. This must be present and working (VRT2 = 1)
1400 * for wakeup and kickstart functionality to be useful.
1401 */
1402 ds1685_rtc_switch_to_bank1(rtc);
1403 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
1404 if (ctrl4a & RTC_CTRL_4A_VRT2) {
1405 /* Clear all of the interrupt flags on Control 4A. */
1406 ctrl4a &= ~(RTC_CTRL_4A_RWK_MASK);
1407 rtc->write(rtc, RTC_EXT_CTRL_4A, ctrl4a);
1408
1409 /*
1410 * The auxillary battery is present and working.
1411 * Enable extended functions (ABE=1), enable
1412 * wake-up (WIE=1), and enable kickstart (KSE=1)
1413 * in Control 4B.
1414 */
1415 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
1416 ctrl4b |= (RTC_CTRL_4B_ABE | RTC_CTRL_4B_WIE |
1417 RTC_CTRL_4B_KSE);
1418 rtc->write(rtc, RTC_EXT_CTRL_4B, ctrl4b);
1419 }
1420
1421 /* Set PAB to 1 in Control 4A to power the system down. */
1422 dev_warn(&pdev->dev, "Powerdown.\n");
1423 msleep(20);
1424 rtc->write(rtc, RTC_EXT_CTRL_4A,
1425 (ctrl4a | RTC_CTRL_4A_PAB));
1426
1427 /* Spin ... we do not switch back to bank0. */
1428 while(1);
1429 unreachable();
1430 }
1431}
1432EXPORT_SYMBOL_GPL(ds1685_rtc_poweroff);
1433/* ----------------------------------------------------------------------- */
1434
1435
1436MODULE_AUTHOR("Joshua Kinard <[email protected]>");
1437MODULE_AUTHOR("Matthias Fuchs <[email protected]>");
1438MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver");
1439MODULE_LICENSE("GPL");
1440MODULE_ALIAS("platform:rtc-ds1685");