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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 <kumba@gentoo.org>.
7 * Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@esd-electronics.com>.
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/* Standard read/write functions if platform does not provide overrides */
35
36/**
37 * ds1685_read - read a value from an rtc register.
38 * @rtc: pointer to the ds1685 rtc structure.
39 * @reg: the register address to read.
40 */
41static u8
42ds1685_read(struct ds1685_priv *rtc, int reg)
43{
44 return readb((u8 __iomem *)rtc->regs +
45 (reg * rtc->regstep));
46}
47
48/**
49 * ds1685_write - write a value to an rtc register.
50 * @rtc: pointer to the ds1685 rtc structure.
51 * @reg: the register address to write.
52 * @value: value to write to the register.
53 */
54static void
55ds1685_write(struct ds1685_priv *rtc, int reg, u8 value)
56{
57 writeb(value, ((u8 __iomem *)rtc->regs +
58 (reg * rtc->regstep)));
59}
60/* ----------------------------------------------------------------------- */
61
62
63/* ----------------------------------------------------------------------- */
64/* Inlined functions */
65
66/**
67 * ds1685_rtc_bcd2bin - bcd2bin wrapper in case platform doesn't support BCD.
68 * @rtc: pointer to the ds1685 rtc structure.
69 * @val: u8 time value to consider converting.
70 * @bcd_mask: u8 mask value if BCD mode is used.
71 * @bin_mask: u8 mask value if BIN mode is used.
72 *
73 * Returns the value, converted to BIN if originally in BCD and bcd_mode TRUE.
74 */
75static inline u8
76ds1685_rtc_bcd2bin(struct ds1685_priv *rtc, u8 val, u8 bcd_mask, u8 bin_mask)
77{
78 if (rtc->bcd_mode)
79 return (bcd2bin(val) & bcd_mask);
80
81 return (val & bin_mask);
82}
83
84/**
85 * ds1685_rtc_bin2bcd - bin2bcd wrapper in case platform doesn't support BCD.
86 * @rtc: pointer to the ds1685 rtc structure.
87 * @val: u8 time value to consider converting.
88 * @bin_mask: u8 mask value if BIN mode is used.
89 * @bcd_mask: u8 mask value if BCD mode is used.
90 *
91 * Returns the value, converted to BCD if originally in BIN and bcd_mode TRUE.
92 */
93static inline u8
94ds1685_rtc_bin2bcd(struct ds1685_priv *rtc, u8 val, u8 bin_mask, u8 bcd_mask)
95{
96 if (rtc->bcd_mode)
97 return (bin2bcd(val) & bcd_mask);
98
99 return (val & bin_mask);
100}
101
102/**
103 * s1685_rtc_check_mday - check validity of the day of month.
104 * @rtc: pointer to the ds1685 rtc structure.
105 * @mday: day of month.
106 *
107 * Returns -EDOM if the day of month is not within 1..31 range.
108 */
109static inline int
110ds1685_rtc_check_mday(struct ds1685_priv *rtc, u8 mday)
111{
112 if (rtc->bcd_mode) {
113 if (mday < 0x01 || mday > 0x31 || (mday & 0x0f) > 0x09)
114 return -EDOM;
115 } else {
116 if (mday < 1 || mday > 31)
117 return -EDOM;
118 }
119 return 0;
120}
121
122/**
123 * ds1685_rtc_switch_to_bank0 - switch the rtc to bank 0.
124 * @rtc: pointer to the ds1685 rtc structure.
125 */
126static inline void
127ds1685_rtc_switch_to_bank0(struct ds1685_priv *rtc)
128{
129 rtc->write(rtc, RTC_CTRL_A,
130 (rtc->read(rtc, RTC_CTRL_A) & ~(RTC_CTRL_A_DV0)));
131}
132
133/**
134 * ds1685_rtc_switch_to_bank1 - switch the rtc to bank 1.
135 * @rtc: pointer to the ds1685 rtc structure.
136 */
137static inline void
138ds1685_rtc_switch_to_bank1(struct ds1685_priv *rtc)
139{
140 rtc->write(rtc, RTC_CTRL_A,
141 (rtc->read(rtc, RTC_CTRL_A) | RTC_CTRL_A_DV0));
142}
143
144/**
145 * ds1685_rtc_begin_data_access - prepare the rtc for data access.
146 * @rtc: pointer to the ds1685 rtc structure.
147 *
148 * This takes several steps to prepare the rtc for access to get/set time
149 * and alarm values from the rtc registers:
150 * - Sets the SET bit in Control Register B.
151 * - Reads Ext Control Register 4A and checks the INCR bit.
152 * - If INCR is active, a short delay is added before Ext Control Register 4A
153 * is read again in a loop until INCR is inactive.
154 * - Switches the rtc to bank 1. This allows access to all relevant
155 * data for normal rtc operation, as bank 0 contains only the nvram.
156 */
157static inline void
158ds1685_rtc_begin_data_access(struct ds1685_priv *rtc)
159{
160 /* Set the SET bit in Ctrl B */
161 rtc->write(rtc, RTC_CTRL_B,
162 (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
163
164 /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
165 while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
166 cpu_relax();
167
168 /* Switch to Bank 1 */
169 ds1685_rtc_switch_to_bank1(rtc);
170}
171
172/**
173 * ds1685_rtc_end_data_access - end data access on the rtc.
174 * @rtc: pointer to the ds1685 rtc structure.
175 *
176 * This ends what was started by ds1685_rtc_begin_data_access:
177 * - Switches the rtc back to bank 0.
178 * - Clears the SET bit in Control Register B.
179 */
180static inline void
181ds1685_rtc_end_data_access(struct ds1685_priv *rtc)
182{
183 /* Switch back to Bank 0 */
184 ds1685_rtc_switch_to_bank1(rtc);
185
186 /* Clear the SET bit in Ctrl B */
187 rtc->write(rtc, RTC_CTRL_B,
188 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
189}
190
191/**
192 * ds1685_rtc_get_ssn - retrieve the silicon serial number.
193 * @rtc: pointer to the ds1685 rtc structure.
194 * @ssn: u8 array to hold the bits of the silicon serial number.
195 *
196 * This number starts at 0x40, and is 8-bytes long, ending at 0x47. The
197 * first byte is the model number, the next six bytes are the serial number
198 * digits, and the final byte is a CRC check byte. Together, they form the
199 * silicon serial number.
200 *
201 * These values are stored in bank1, so ds1685_rtc_switch_to_bank1 must be
202 * called first before calling this function, else data will be read out of
203 * the bank0 NVRAM. Be sure to call ds1685_rtc_switch_to_bank0 when done.
204 */
205static inline void
206ds1685_rtc_get_ssn(struct ds1685_priv *rtc, u8 *ssn)
207{
208 ssn[0] = rtc->read(rtc, RTC_BANK1_SSN_MODEL);
209 ssn[1] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_1);
210 ssn[2] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_2);
211 ssn[3] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_3);
212 ssn[4] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_4);
213 ssn[5] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_5);
214 ssn[6] = rtc->read(rtc, RTC_BANK1_SSN_BYTE_6);
215 ssn[7] = rtc->read(rtc, RTC_BANK1_SSN_CRC);
216}
217/* ----------------------------------------------------------------------- */
218
219
220/* ----------------------------------------------------------------------- */
221/* Read/Set Time & Alarm functions */
222
223/**
224 * ds1685_rtc_read_time - reads the time registers.
225 * @dev: pointer to device structure.
226 * @tm: pointer to rtc_time structure.
227 */
228static int
229ds1685_rtc_read_time(struct device *dev, struct rtc_time *tm)
230{
231 struct ds1685_priv *rtc = dev_get_drvdata(dev);
232 u8 ctrlb, century;
233 u8 seconds, minutes, hours, wday, mday, month, years;
234
235 /* Fetch the time info from the RTC registers. */
236 ds1685_rtc_begin_data_access(rtc);
237 seconds = rtc->read(rtc, RTC_SECS);
238 minutes = rtc->read(rtc, RTC_MINS);
239 hours = rtc->read(rtc, RTC_HRS);
240 wday = rtc->read(rtc, RTC_WDAY);
241 mday = rtc->read(rtc, RTC_MDAY);
242 month = rtc->read(rtc, RTC_MONTH);
243 years = rtc->read(rtc, RTC_YEAR);
244 century = rtc->read(rtc, RTC_CENTURY);
245 ctrlb = rtc->read(rtc, RTC_CTRL_B);
246 ds1685_rtc_end_data_access(rtc);
247
248 /* bcd2bin if needed, perform fixups, and store to rtc_time. */
249 years = ds1685_rtc_bcd2bin(rtc, years, RTC_YEAR_BCD_MASK,
250 RTC_YEAR_BIN_MASK);
251 century = ds1685_rtc_bcd2bin(rtc, century, RTC_CENTURY_MASK,
252 RTC_CENTURY_MASK);
253 tm->tm_sec = ds1685_rtc_bcd2bin(rtc, seconds, RTC_SECS_BCD_MASK,
254 RTC_SECS_BIN_MASK);
255 tm->tm_min = ds1685_rtc_bcd2bin(rtc, minutes, RTC_MINS_BCD_MASK,
256 RTC_MINS_BIN_MASK);
257 tm->tm_hour = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_24_BCD_MASK,
258 RTC_HRS_24_BIN_MASK);
259 tm->tm_wday = (ds1685_rtc_bcd2bin(rtc, wday, RTC_WDAY_MASK,
260 RTC_WDAY_MASK) - 1);
261 tm->tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
262 RTC_MDAY_BIN_MASK);
263 tm->tm_mon = (ds1685_rtc_bcd2bin(rtc, month, RTC_MONTH_BCD_MASK,
264 RTC_MONTH_BIN_MASK) - 1);
265 tm->tm_year = ((years + (century * 100)) - 1900);
266 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
267 tm->tm_isdst = 0; /* RTC has hardcoded timezone, so don't use. */
268
269 return 0;
270}
271
272/**
273 * ds1685_rtc_set_time - sets the time registers.
274 * @dev: pointer to device structure.
275 * @tm: pointer to rtc_time structure.
276 */
277static int
278ds1685_rtc_set_time(struct device *dev, struct rtc_time *tm)
279{
280 struct ds1685_priv *rtc = dev_get_drvdata(dev);
281 u8 ctrlb, seconds, minutes, hours, wday, mday, month, years, century;
282
283 /* Fetch the time info from rtc_time. */
284 seconds = ds1685_rtc_bin2bcd(rtc, tm->tm_sec, RTC_SECS_BIN_MASK,
285 RTC_SECS_BCD_MASK);
286 minutes = ds1685_rtc_bin2bcd(rtc, tm->tm_min, RTC_MINS_BIN_MASK,
287 RTC_MINS_BCD_MASK);
288 hours = ds1685_rtc_bin2bcd(rtc, tm->tm_hour, RTC_HRS_24_BIN_MASK,
289 RTC_HRS_24_BCD_MASK);
290 wday = ds1685_rtc_bin2bcd(rtc, (tm->tm_wday + 1), RTC_WDAY_MASK,
291 RTC_WDAY_MASK);
292 mday = ds1685_rtc_bin2bcd(rtc, tm->tm_mday, RTC_MDAY_BIN_MASK,
293 RTC_MDAY_BCD_MASK);
294 month = ds1685_rtc_bin2bcd(rtc, (tm->tm_mon + 1), RTC_MONTH_BIN_MASK,
295 RTC_MONTH_BCD_MASK);
296 years = ds1685_rtc_bin2bcd(rtc, (tm->tm_year % 100),
297 RTC_YEAR_BIN_MASK, RTC_YEAR_BCD_MASK);
298 century = ds1685_rtc_bin2bcd(rtc, ((tm->tm_year + 1900) / 100),
299 RTC_CENTURY_MASK, RTC_CENTURY_MASK);
300
301 /*
302 * Perform Sanity Checks:
303 * - Months: !> 12, Month Day != 0.
304 * - Month Day !> Max days in current month.
305 * - Hours !>= 24, Mins !>= 60, Secs !>= 60, & Weekday !> 7.
306 */
307 if ((tm->tm_mon > 11) || (mday == 0))
308 return -EDOM;
309
310 if (tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year))
311 return -EDOM;
312
313 if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) ||
314 (tm->tm_sec >= 60) || (wday > 7))
315 return -EDOM;
316
317 /*
318 * Set the data mode to use and store the time values in the
319 * RTC registers.
320 */
321 ds1685_rtc_begin_data_access(rtc);
322 ctrlb = rtc->read(rtc, RTC_CTRL_B);
323 if (rtc->bcd_mode)
324 ctrlb &= ~(RTC_CTRL_B_DM);
325 else
326 ctrlb |= RTC_CTRL_B_DM;
327 rtc->write(rtc, RTC_CTRL_B, ctrlb);
328 rtc->write(rtc, RTC_SECS, seconds);
329 rtc->write(rtc, RTC_MINS, minutes);
330 rtc->write(rtc, RTC_HRS, hours);
331 rtc->write(rtc, RTC_WDAY, wday);
332 rtc->write(rtc, RTC_MDAY, mday);
333 rtc->write(rtc, RTC_MONTH, month);
334 rtc->write(rtc, RTC_YEAR, years);
335 rtc->write(rtc, RTC_CENTURY, century);
336 ds1685_rtc_end_data_access(rtc);
337
338 return 0;
339}
340
341/**
342 * ds1685_rtc_read_alarm - reads the alarm registers.
343 * @dev: pointer to device structure.
344 * @alrm: pointer to rtc_wkalrm structure.
345 *
346 * There are three primary alarm registers: seconds, minutes, and hours.
347 * A fourth alarm register for the month date is also available in bank1 for
348 * kickstart/wakeup features. The DS1685/DS1687 manual states that a
349 * "don't care" value ranging from 0xc0 to 0xff may be written into one or
350 * more of the three alarm bytes to act as a wildcard value. The fourth
351 * byte doesn't support a "don't care" value.
352 */
353static int
354ds1685_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
355{
356 struct ds1685_priv *rtc = dev_get_drvdata(dev);
357 u8 seconds, minutes, hours, mday, ctrlb, ctrlc;
358 int ret;
359
360 /* Fetch the alarm info from the RTC alarm registers. */
361 ds1685_rtc_begin_data_access(rtc);
362 seconds = rtc->read(rtc, RTC_SECS_ALARM);
363 minutes = rtc->read(rtc, RTC_MINS_ALARM);
364 hours = rtc->read(rtc, RTC_HRS_ALARM);
365 mday = rtc->read(rtc, RTC_MDAY_ALARM);
366 ctrlb = rtc->read(rtc, RTC_CTRL_B);
367 ctrlc = rtc->read(rtc, RTC_CTRL_C);
368 ds1685_rtc_end_data_access(rtc);
369
370 /* Check the month date for validity. */
371 ret = ds1685_rtc_check_mday(rtc, mday);
372 if (ret)
373 return ret;
374
375 /*
376 * Check the three alarm bytes.
377 *
378 * The Linux RTC system doesn't support the "don't care" capability
379 * of this RTC chip. We check for it anyways in case support is
380 * added in the future and only assign when we care.
381 */
382 if (likely(seconds < 0xc0))
383 alrm->time.tm_sec = ds1685_rtc_bcd2bin(rtc, seconds,
384 RTC_SECS_BCD_MASK,
385 RTC_SECS_BIN_MASK);
386
387 if (likely(minutes < 0xc0))
388 alrm->time.tm_min = ds1685_rtc_bcd2bin(rtc, minutes,
389 RTC_MINS_BCD_MASK,
390 RTC_MINS_BIN_MASK);
391
392 if (likely(hours < 0xc0))
393 alrm->time.tm_hour = ds1685_rtc_bcd2bin(rtc, hours,
394 RTC_HRS_24_BCD_MASK,
395 RTC_HRS_24_BIN_MASK);
396
397 /* Write the data to rtc_wkalrm. */
398 alrm->time.tm_mday = ds1685_rtc_bcd2bin(rtc, mday, RTC_MDAY_BCD_MASK,
399 RTC_MDAY_BIN_MASK);
400 alrm->enabled = !!(ctrlb & RTC_CTRL_B_AIE);
401 alrm->pending = !!(ctrlc & RTC_CTRL_C_AF);
402
403 return 0;
404}
405
406/**
407 * ds1685_rtc_set_alarm - sets the alarm in registers.
408 * @dev: pointer to device structure.
409 * @alrm: pointer to rtc_wkalrm structure.
410 */
411static int
412ds1685_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
413{
414 struct ds1685_priv *rtc = dev_get_drvdata(dev);
415 u8 ctrlb, seconds, minutes, hours, mday;
416 int ret;
417
418 /* Fetch the alarm info and convert to BCD. */
419 seconds = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_sec,
420 RTC_SECS_BIN_MASK,
421 RTC_SECS_BCD_MASK);
422 minutes = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_min,
423 RTC_MINS_BIN_MASK,
424 RTC_MINS_BCD_MASK);
425 hours = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_hour,
426 RTC_HRS_24_BIN_MASK,
427 RTC_HRS_24_BCD_MASK);
428 mday = ds1685_rtc_bin2bcd(rtc, alrm->time.tm_mday,
429 RTC_MDAY_BIN_MASK,
430 RTC_MDAY_BCD_MASK);
431
432 /* Check the month date for validity. */
433 ret = ds1685_rtc_check_mday(rtc, mday);
434 if (ret)
435 return ret;
436
437 /*
438 * Check the three alarm bytes.
439 *
440 * The Linux RTC system doesn't support the "don't care" capability
441 * of this RTC chip because rtc_valid_tm tries to validate every
442 * field, and we only support four fields. We put the support
443 * here anyways for the future.
444 */
445 if (unlikely(seconds >= 0xc0))
446 seconds = 0xff;
447
448 if (unlikely(minutes >= 0xc0))
449 minutes = 0xff;
450
451 if (unlikely(hours >= 0xc0))
452 hours = 0xff;
453
454 alrm->time.tm_mon = -1;
455 alrm->time.tm_year = -1;
456 alrm->time.tm_wday = -1;
457 alrm->time.tm_yday = -1;
458 alrm->time.tm_isdst = -1;
459
460 /* Disable the alarm interrupt first. */
461 ds1685_rtc_begin_data_access(rtc);
462 ctrlb = rtc->read(rtc, RTC_CTRL_B);
463 rtc->write(rtc, RTC_CTRL_B, (ctrlb & ~(RTC_CTRL_B_AIE)));
464
465 /* Read ctrlc to clear RTC_CTRL_C_AF. */
466 rtc->read(rtc, RTC_CTRL_C);
467
468 /*
469 * Set the data mode to use and store the time values in the
470 * RTC registers.
471 */
472 ctrlb = rtc->read(rtc, RTC_CTRL_B);
473 if (rtc->bcd_mode)
474 ctrlb &= ~(RTC_CTRL_B_DM);
475 else
476 ctrlb |= RTC_CTRL_B_DM;
477 rtc->write(rtc, RTC_CTRL_B, ctrlb);
478 rtc->write(rtc, RTC_SECS_ALARM, seconds);
479 rtc->write(rtc, RTC_MINS_ALARM, minutes);
480 rtc->write(rtc, RTC_HRS_ALARM, hours);
481 rtc->write(rtc, RTC_MDAY_ALARM, mday);
482
483 /* Re-enable the alarm if needed. */
484 if (alrm->enabled) {
485 ctrlb = rtc->read(rtc, RTC_CTRL_B);
486 ctrlb |= RTC_CTRL_B_AIE;
487 rtc->write(rtc, RTC_CTRL_B, ctrlb);
488 }
489
490 /* Done! */
491 ds1685_rtc_end_data_access(rtc);
492
493 return 0;
494}
495/* ----------------------------------------------------------------------- */
496
497
498/* ----------------------------------------------------------------------- */
499/* /dev/rtcX Interface functions */
500
501/**
502 * ds1685_rtc_alarm_irq_enable - replaces ioctl() RTC_AIE on/off.
503 * @dev: pointer to device structure.
504 * @enabled: flag indicating whether to enable or disable.
505 */
506static int
507ds1685_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
508{
509 struct ds1685_priv *rtc = dev_get_drvdata(dev);
510
511 /* Flip the requisite interrupt-enable bit. */
512 if (enabled)
513 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) |
514 RTC_CTRL_B_AIE));
515 else
516 rtc->write(rtc, RTC_CTRL_B, (rtc->read(rtc, RTC_CTRL_B) &
517 ~(RTC_CTRL_B_AIE)));
518
519 /* Read Control C to clear all the flag bits. */
520 rtc->read(rtc, RTC_CTRL_C);
521
522 return 0;
523}
524/* ----------------------------------------------------------------------- */
525
526
527/* ----------------------------------------------------------------------- */
528/* IRQ handler */
529
530/**
531 * ds1685_rtc_extended_irq - take care of extended interrupts
532 * @rtc: pointer to the ds1685 rtc structure.
533 * @pdev: platform device pointer.
534 */
535static void
536ds1685_rtc_extended_irq(struct ds1685_priv *rtc, struct platform_device *pdev)
537{
538 u8 ctrl4a, ctrl4b;
539
540 ds1685_rtc_switch_to_bank1(rtc);
541 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
542 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
543
544 /*
545 * Check for a kickstart interrupt. With Vcc applied, this
546 * typically means that the power button was pressed, so we
547 * begin the shutdown sequence.
548 */
549 if ((ctrl4b & RTC_CTRL_4B_KSE) && (ctrl4a & RTC_CTRL_4A_KF)) {
550 /* Briefly disable kickstarts to debounce button presses. */
551 rtc->write(rtc, RTC_EXT_CTRL_4B,
552 (rtc->read(rtc, RTC_EXT_CTRL_4B) &
553 ~(RTC_CTRL_4B_KSE)));
554
555 /* Clear the kickstart flag. */
556 rtc->write(rtc, RTC_EXT_CTRL_4A,
557 (ctrl4a & ~(RTC_CTRL_4A_KF)));
558
559
560 /*
561 * Sleep 500ms before re-enabling kickstarts. This allows
562 * adequate time to avoid reading signal jitter as additional
563 * button presses.
564 */
565 msleep(500);
566 rtc->write(rtc, RTC_EXT_CTRL_4B,
567 (rtc->read(rtc, RTC_EXT_CTRL_4B) |
568 RTC_CTRL_4B_KSE));
569
570 /* Call the platform pre-poweroff function. Else, shutdown. */
571 if (rtc->prepare_poweroff != NULL)
572 rtc->prepare_poweroff();
573 else
574 ds1685_rtc_poweroff(pdev);
575 }
576
577 /*
578 * Check for a wake-up interrupt. With Vcc applied, this is
579 * essentially a second alarm interrupt, except it takes into
580 * account the 'date' register in bank1 in addition to the
581 * standard three alarm registers.
582 */
583 if ((ctrl4b & RTC_CTRL_4B_WIE) && (ctrl4a & RTC_CTRL_4A_WF)) {
584 rtc->write(rtc, RTC_EXT_CTRL_4A,
585 (ctrl4a & ~(RTC_CTRL_4A_WF)));
586
587 /* Call the platform wake_alarm function if defined. */
588 if (rtc->wake_alarm != NULL)
589 rtc->wake_alarm();
590 else
591 dev_warn(&pdev->dev,
592 "Wake Alarm IRQ just occurred!\n");
593 }
594
595 /*
596 * Check for a ram-clear interrupt. This happens if RIE=1 and RF=0
597 * when RCE=1 in 4B. This clears all NVRAM bytes in bank0 by setting
598 * each byte to a logic 1. This has no effect on any extended
599 * NV-SRAM that might be present, nor on the time/calendar/alarm
600 * registers. After a ram-clear is completed, there is a minimum
601 * recovery time of ~150ms in which all reads/writes are locked out.
602 * NOTE: A ram-clear can still occur if RCE=1 and RIE=0. We cannot
603 * catch this scenario.
604 */
605 if ((ctrl4b & RTC_CTRL_4B_RIE) && (ctrl4a & RTC_CTRL_4A_RF)) {
606 rtc->write(rtc, RTC_EXT_CTRL_4A,
607 (ctrl4a & ~(RTC_CTRL_4A_RF)));
608 msleep(150);
609
610 /* Call the platform post_ram_clear function if defined. */
611 if (rtc->post_ram_clear != NULL)
612 rtc->post_ram_clear();
613 else
614 dev_warn(&pdev->dev,
615 "RAM-Clear IRQ just occurred!\n");
616 }
617 ds1685_rtc_switch_to_bank0(rtc);
618}
619
620/**
621 * ds1685_rtc_irq_handler - IRQ handler.
622 * @irq: IRQ number.
623 * @dev_id: platform device pointer.
624 */
625static irqreturn_t
626ds1685_rtc_irq_handler(int irq, void *dev_id)
627{
628 struct platform_device *pdev = dev_id;
629 struct ds1685_priv *rtc = platform_get_drvdata(pdev);
630 struct mutex *rtc_mutex;
631 u8 ctrlb, ctrlc;
632 unsigned long events = 0;
633 u8 num_irqs = 0;
634
635 /* Abort early if the device isn't ready yet (i.e., DEBUG_SHIRQ). */
636 if (unlikely(!rtc))
637 return IRQ_HANDLED;
638
639 rtc_mutex = &rtc->dev->ops_lock;
640 mutex_lock(rtc_mutex);
641
642 /* Ctrlb holds the interrupt-enable bits and ctrlc the flag bits. */
643 ctrlb = rtc->read(rtc, RTC_CTRL_B);
644 ctrlc = rtc->read(rtc, RTC_CTRL_C);
645
646 /* Is the IRQF bit set? */
647 if (likely(ctrlc & RTC_CTRL_C_IRQF)) {
648 /*
649 * We need to determine if it was one of the standard
650 * events: PF, AF, or UF. If so, we handle them and
651 * update the RTC core.
652 */
653 if (likely(ctrlc & RTC_CTRL_B_PAU_MASK)) {
654 events = RTC_IRQF;
655
656 /* Check for a periodic interrupt. */
657 if ((ctrlb & RTC_CTRL_B_PIE) &&
658 (ctrlc & RTC_CTRL_C_PF)) {
659 events |= RTC_PF;
660 num_irqs++;
661 }
662
663 /* Check for an alarm interrupt. */
664 if ((ctrlb & RTC_CTRL_B_AIE) &&
665 (ctrlc & RTC_CTRL_C_AF)) {
666 events |= RTC_AF;
667 num_irqs++;
668 }
669
670 /* Check for an update interrupt. */
671 if ((ctrlb & RTC_CTRL_B_UIE) &&
672 (ctrlc & RTC_CTRL_C_UF)) {
673 events |= RTC_UF;
674 num_irqs++;
675 }
676 } else {
677 /*
678 * One of the "extended" interrupts was received that
679 * is not recognized by the RTC core.
680 */
681 ds1685_rtc_extended_irq(rtc, pdev);
682 }
683 }
684 rtc_update_irq(rtc->dev, num_irqs, events);
685 mutex_unlock(rtc_mutex);
686
687 return events ? IRQ_HANDLED : IRQ_NONE;
688}
689/* ----------------------------------------------------------------------- */
690
691
692/* ----------------------------------------------------------------------- */
693/* ProcFS interface */
694
695#ifdef CONFIG_PROC_FS
696#define NUM_REGS 6 /* Num of control registers. */
697#define NUM_BITS 8 /* Num bits per register. */
698#define NUM_SPACES 4 /* Num spaces between each bit. */
699
700/*
701 * Periodic Interrupt Rates.
702 */
703static const char *ds1685_rtc_pirq_rate[16] = {
704 "none", "3.90625ms", "7.8125ms", "0.122070ms", "0.244141ms",
705 "0.488281ms", "0.9765625ms", "1.953125ms", "3.90625ms", "7.8125ms",
706 "15.625ms", "31.25ms", "62.5ms", "125ms", "250ms", "500ms"
707};
708
709/*
710 * Square-Wave Output Frequencies.
711 */
712static const char *ds1685_rtc_sqw_freq[16] = {
713 "none", "256Hz", "128Hz", "8192Hz", "4096Hz", "2048Hz", "1024Hz",
714 "512Hz", "256Hz", "128Hz", "64Hz", "32Hz", "16Hz", "8Hz", "4Hz", "2Hz"
715};
716
717/**
718 * ds1685_rtc_proc - procfs access function.
719 * @dev: pointer to device structure.
720 * @seq: pointer to seq_file structure.
721 */
722static int
723ds1685_rtc_proc(struct device *dev, struct seq_file *seq)
724{
725 struct ds1685_priv *rtc = dev_get_drvdata(dev);
726 u8 ctrla, ctrlb, ctrlc, ctrld, ctrl4a, ctrl4b, ssn[8];
727 char *model;
728
729 /* Read all the relevant data from the control registers. */
730 ds1685_rtc_switch_to_bank1(rtc);
731 ds1685_rtc_get_ssn(rtc, ssn);
732 ctrla = rtc->read(rtc, RTC_CTRL_A);
733 ctrlb = rtc->read(rtc, RTC_CTRL_B);
734 ctrlc = rtc->read(rtc, RTC_CTRL_C);
735 ctrld = rtc->read(rtc, RTC_CTRL_D);
736 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
737 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
738 ds1685_rtc_switch_to_bank0(rtc);
739
740 /* Determine the RTC model. */
741 switch (ssn[0]) {
742 case RTC_MODEL_DS1685:
743 model = "DS1685/DS1687\0";
744 break;
745 case RTC_MODEL_DS1689:
746 model = "DS1689/DS1693\0";
747 break;
748 case RTC_MODEL_DS17285:
749 model = "DS17285/DS17287\0";
750 break;
751 case RTC_MODEL_DS17485:
752 model = "DS17485/DS17487\0";
753 break;
754 case RTC_MODEL_DS17885:
755 model = "DS17885/DS17887\0";
756 break;
757 default:
758 model = "Unknown\0";
759 break;
760 }
761
762 /* Print out the information. */
763 seq_printf(seq,
764 "Model\t\t: %s\n"
765 "Oscillator\t: %s\n"
766 "12/24hr\t\t: %s\n"
767 "DST\t\t: %s\n"
768 "Data mode\t: %s\n"
769 "Battery\t\t: %s\n"
770 "Aux batt\t: %s\n"
771 "Update IRQ\t: %s\n"
772 "Periodic IRQ\t: %s\n"
773 "Periodic Rate\t: %s\n"
774 "SQW Freq\t: %s\n"
775 "Serial #\t: %8phC\n",
776 model,
777 ((ctrla & RTC_CTRL_A_DV1) ? "enabled" : "disabled"),
778 ((ctrlb & RTC_CTRL_B_2412) ? "24-hour" : "12-hour"),
779 ((ctrlb & RTC_CTRL_B_DSE) ? "enabled" : "disabled"),
780 ((ctrlb & RTC_CTRL_B_DM) ? "binary" : "BCD"),
781 ((ctrld & RTC_CTRL_D_VRT) ? "ok" : "exhausted or n/a"),
782 ((ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "exhausted or n/a"),
783 ((ctrlb & RTC_CTRL_B_UIE) ? "yes" : "no"),
784 ((ctrlb & RTC_CTRL_B_PIE) ? "yes" : "no"),
785 (!(ctrl4b & RTC_CTRL_4B_E32K) ?
786 ds1685_rtc_pirq_rate[(ctrla & RTC_CTRL_A_RS_MASK)] : "none"),
787 (!((ctrl4b & RTC_CTRL_4B_E32K)) ?
788 ds1685_rtc_sqw_freq[(ctrla & RTC_CTRL_A_RS_MASK)] : "32768Hz"),
789 ssn);
790 return 0;
791}
792#else
793#define ds1685_rtc_proc NULL
794#endif /* CONFIG_PROC_FS */
795/* ----------------------------------------------------------------------- */
796
797
798/* ----------------------------------------------------------------------- */
799/* RTC Class operations */
800
801static const struct rtc_class_ops
802ds1685_rtc_ops = {
803 .proc = ds1685_rtc_proc,
804 .read_time = ds1685_rtc_read_time,
805 .set_time = ds1685_rtc_set_time,
806 .read_alarm = ds1685_rtc_read_alarm,
807 .set_alarm = ds1685_rtc_set_alarm,
808 .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,
809};
810/* ----------------------------------------------------------------------- */
811
812static int ds1685_nvram_read(void *priv, unsigned int pos, void *val,
813 size_t size)
814{
815 struct ds1685_priv *rtc = priv;
816 struct mutex *rtc_mutex = &rtc->dev->ops_lock;
817 ssize_t count;
818 u8 *buf = val;
819 int err;
820
821 err = mutex_lock_interruptible(rtc_mutex);
822 if (err)
823 return err;
824
825 ds1685_rtc_switch_to_bank0(rtc);
826
827 /* Read NVRAM in time and bank0 registers. */
828 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
829 count++, size--) {
830 if (count < NVRAM_SZ_TIME)
831 *buf++ = rtc->read(rtc, (NVRAM_TIME_BASE + pos++));
832 else
833 *buf++ = rtc->read(rtc, (NVRAM_BANK0_BASE + pos++));
834 }
835
836#ifndef CONFIG_RTC_DRV_DS1689
837 if (size > 0) {
838 ds1685_rtc_switch_to_bank1(rtc);
839
840#ifndef CONFIG_RTC_DRV_DS1685
841 /* Enable burst-mode on DS17x85/DS17x87 */
842 rtc->write(rtc, RTC_EXT_CTRL_4A,
843 (rtc->read(rtc, RTC_EXT_CTRL_4A) |
844 RTC_CTRL_4A_BME));
845
846 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
847 * reading with burst-mode */
848 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
849 (pos - NVRAM_TOTAL_SZ_BANK0));
850#endif
851
852 /* Read NVRAM in bank1 registers. */
853 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
854 count++, size--) {
855#ifdef CONFIG_RTC_DRV_DS1685
856 /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
857 * before each read. */
858 rtc->write(rtc, RTC_BANK1_RAM_ADDR,
859 (pos - NVRAM_TOTAL_SZ_BANK0));
860#endif
861 *buf++ = rtc->read(rtc, RTC_BANK1_RAM_DATA_PORT);
862 pos++;
863 }
864
865#ifndef CONFIG_RTC_DRV_DS1685
866 /* Disable burst-mode on DS17x85/DS17x87 */
867 rtc->write(rtc, RTC_EXT_CTRL_4A,
868 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
869 ~(RTC_CTRL_4A_BME)));
870#endif
871 ds1685_rtc_switch_to_bank0(rtc);
872 }
873#endif /* !CONFIG_RTC_DRV_DS1689 */
874 mutex_unlock(rtc_mutex);
875
876 return 0;
877}
878
879static int ds1685_nvram_write(void *priv, unsigned int pos, void *val,
880 size_t size)
881{
882 struct ds1685_priv *rtc = priv;
883 struct mutex *rtc_mutex = &rtc->dev->ops_lock;
884 ssize_t count;
885 u8 *buf = val;
886 int err;
887
888 err = mutex_lock_interruptible(rtc_mutex);
889 if (err)
890 return err;
891
892 ds1685_rtc_switch_to_bank0(rtc);
893
894 /* Write NVRAM in time and bank0 registers. */
895 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ_BANK0;
896 count++, size--)
897 if (count < NVRAM_SZ_TIME)
898 rtc->write(rtc, (NVRAM_TIME_BASE + pos++),
899 *buf++);
900 else
901 rtc->write(rtc, (NVRAM_BANK0_BASE), *buf++);
902
903#ifndef CONFIG_RTC_DRV_DS1689
904 if (size > 0) {
905 ds1685_rtc_switch_to_bank1(rtc);
906
907#ifndef CONFIG_RTC_DRV_DS1685
908 /* Enable burst-mode on DS17x85/DS17x87 */
909 rtc->write(rtc, RTC_EXT_CTRL_4A,
910 (rtc->read(rtc, RTC_EXT_CTRL_4A) |
911 RTC_CTRL_4A_BME));
912
913 /* We need one write to RTC_BANK1_RAM_ADDR_LSB to start
914 * writing with burst-mode */
915 rtc->write(rtc, RTC_BANK1_RAM_ADDR_LSB,
916 (pos - NVRAM_TOTAL_SZ_BANK0));
917#endif
918
919 /* Write NVRAM in bank1 registers. */
920 for (count = 0; size > 0 && pos < NVRAM_TOTAL_SZ;
921 count++, size--) {
922#ifdef CONFIG_RTC_DRV_DS1685
923 /* DS1685/DS1687 has to write to RTC_BANK1_RAM_ADDR
924 * before each read. */
925 rtc->write(rtc, RTC_BANK1_RAM_ADDR,
926 (pos - NVRAM_TOTAL_SZ_BANK0));
927#endif
928 rtc->write(rtc, RTC_BANK1_RAM_DATA_PORT, *buf++);
929 pos++;
930 }
931
932#ifndef CONFIG_RTC_DRV_DS1685
933 /* Disable burst-mode on DS17x85/DS17x87 */
934 rtc->write(rtc, RTC_EXT_CTRL_4A,
935 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
936 ~(RTC_CTRL_4A_BME)));
937#endif
938 ds1685_rtc_switch_to_bank0(rtc);
939 }
940#endif /* !CONFIG_RTC_DRV_DS1689 */
941 mutex_unlock(rtc_mutex);
942
943 return 0;
944}
945
946/* ----------------------------------------------------------------------- */
947/* SysFS interface */
948
949/**
950 * ds1685_rtc_sysfs_battery_show - sysfs file for main battery status.
951 * @dev: pointer to device structure.
952 * @attr: pointer to device_attribute structure.
953 * @buf: pointer to char array to hold the output.
954 */
955static ssize_t
956ds1685_rtc_sysfs_battery_show(struct device *dev,
957 struct device_attribute *attr, char *buf)
958{
959 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
960 u8 ctrld;
961
962 ctrld = rtc->read(rtc, RTC_CTRL_D);
963
964 return sprintf(buf, "%s\n",
965 (ctrld & RTC_CTRL_D_VRT) ? "ok" : "not ok or N/A");
966}
967static DEVICE_ATTR(battery, S_IRUGO, ds1685_rtc_sysfs_battery_show, NULL);
968
969/**
970 * ds1685_rtc_sysfs_auxbatt_show - sysfs file for aux battery status.
971 * @dev: pointer to device structure.
972 * @attr: pointer to device_attribute structure.
973 * @buf: pointer to char array to hold the output.
974 */
975static ssize_t
976ds1685_rtc_sysfs_auxbatt_show(struct device *dev,
977 struct device_attribute *attr, char *buf)
978{
979 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
980 u8 ctrl4a;
981
982 ds1685_rtc_switch_to_bank1(rtc);
983 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
984 ds1685_rtc_switch_to_bank0(rtc);
985
986 return sprintf(buf, "%s\n",
987 (ctrl4a & RTC_CTRL_4A_VRT2) ? "ok" : "not ok or N/A");
988}
989static DEVICE_ATTR(auxbatt, S_IRUGO, ds1685_rtc_sysfs_auxbatt_show, NULL);
990
991/**
992 * ds1685_rtc_sysfs_serial_show - sysfs file for silicon serial number.
993 * @dev: pointer to device structure.
994 * @attr: pointer to device_attribute structure.
995 * @buf: pointer to char array to hold the output.
996 */
997static ssize_t
998ds1685_rtc_sysfs_serial_show(struct device *dev,
999 struct device_attribute *attr, char *buf)
1000{
1001 struct ds1685_priv *rtc = dev_get_drvdata(dev->parent);
1002 u8 ssn[8];
1003
1004 ds1685_rtc_switch_to_bank1(rtc);
1005 ds1685_rtc_get_ssn(rtc, ssn);
1006 ds1685_rtc_switch_to_bank0(rtc);
1007
1008 return sprintf(buf, "%8phC\n", ssn);
1009}
1010static DEVICE_ATTR(serial, S_IRUGO, ds1685_rtc_sysfs_serial_show, NULL);
1011
1012/**
1013 * struct ds1685_rtc_sysfs_misc_attrs - list for misc RTC features.
1014 */
1015static struct attribute*
1016ds1685_rtc_sysfs_misc_attrs[] = {
1017 &dev_attr_battery.attr,
1018 &dev_attr_auxbatt.attr,
1019 &dev_attr_serial.attr,
1020 NULL,
1021};
1022
1023/**
1024 * struct ds1685_rtc_sysfs_misc_grp - attr group for misc RTC features.
1025 */
1026static const struct attribute_group
1027ds1685_rtc_sysfs_misc_grp = {
1028 .name = "misc",
1029 .attrs = ds1685_rtc_sysfs_misc_attrs,
1030};
1031
1032/* ----------------------------------------------------------------------- */
1033/* Driver Probe/Removal */
1034
1035/**
1036 * ds1685_rtc_probe - initializes rtc driver.
1037 * @pdev: pointer to platform_device structure.
1038 */
1039static int
1040ds1685_rtc_probe(struct platform_device *pdev)
1041{
1042 struct rtc_device *rtc_dev;
1043 struct resource *res;
1044 struct ds1685_priv *rtc;
1045 struct ds1685_rtc_platform_data *pdata;
1046 u8 ctrla, ctrlb, hours;
1047 unsigned char am_pm;
1048 int ret = 0;
1049 struct nvmem_config nvmem_cfg = {
1050 .name = "ds1685_nvram",
1051 .size = NVRAM_TOTAL_SZ,
1052 .reg_read = ds1685_nvram_read,
1053 .reg_write = ds1685_nvram_write,
1054 };
1055
1056 /* Get the platform data. */
1057 pdata = (struct ds1685_rtc_platform_data *) pdev->dev.platform_data;
1058 if (!pdata)
1059 return -ENODEV;
1060
1061 /* Allocate memory for the rtc device. */
1062 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
1063 if (!rtc)
1064 return -ENOMEM;
1065
1066 /*
1067 * Allocate/setup any IORESOURCE_MEM resources, if required. Not all
1068 * platforms put the RTC in an easy-access place. Like the SGI Octane,
1069 * which attaches the RTC to a "ByteBus", hooked to a SuperIO chip
1070 * that sits behind the IOC3 PCI metadevice.
1071 */
1072 if (pdata->alloc_io_resources) {
1073 /* Get the platform resources. */
1074 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1075 if (!res)
1076 return -ENXIO;
1077 rtc->size = resource_size(res);
1078
1079 /* Request a memory region. */
1080 /* XXX: mmio-only for now. */
1081 if (!devm_request_mem_region(&pdev->dev, res->start, rtc->size,
1082 pdev->name))
1083 return -EBUSY;
1084
1085 /*
1086 * Set the base address for the rtc, and ioremap its
1087 * registers.
1088 */
1089 rtc->baseaddr = res->start;
1090 rtc->regs = devm_ioremap(&pdev->dev, res->start, rtc->size);
1091 if (!rtc->regs)
1092 return -ENOMEM;
1093 }
1094 rtc->alloc_io_resources = pdata->alloc_io_resources;
1095
1096 /* Get the register step size. */
1097 if (pdata->regstep > 0)
1098 rtc->regstep = pdata->regstep;
1099 else
1100 rtc->regstep = 1;
1101
1102 /* Platform read function, else default if mmio setup */
1103 if (pdata->plat_read)
1104 rtc->read = pdata->plat_read;
1105 else
1106 if (pdata->alloc_io_resources)
1107 rtc->read = ds1685_read;
1108 else
1109 return -ENXIO;
1110
1111 /* Platform write function, else default if mmio setup */
1112 if (pdata->plat_write)
1113 rtc->write = pdata->plat_write;
1114 else
1115 if (pdata->alloc_io_resources)
1116 rtc->write = ds1685_write;
1117 else
1118 return -ENXIO;
1119
1120 /* Platform pre-shutdown function, if defined. */
1121 if (pdata->plat_prepare_poweroff)
1122 rtc->prepare_poweroff = pdata->plat_prepare_poweroff;
1123
1124 /* Platform wake_alarm function, if defined. */
1125 if (pdata->plat_wake_alarm)
1126 rtc->wake_alarm = pdata->plat_wake_alarm;
1127
1128 /* Platform post_ram_clear function, if defined. */
1129 if (pdata->plat_post_ram_clear)
1130 rtc->post_ram_clear = pdata->plat_post_ram_clear;
1131
1132 /* set the driver data. */
1133 platform_set_drvdata(pdev, rtc);
1134
1135 /* Turn the oscillator on if is not already on (DV1 = 1). */
1136 ctrla = rtc->read(rtc, RTC_CTRL_A);
1137 if (!(ctrla & RTC_CTRL_A_DV1))
1138 ctrla |= RTC_CTRL_A_DV1;
1139
1140 /* Enable the countdown chain (DV2 = 0) */
1141 ctrla &= ~(RTC_CTRL_A_DV2);
1142
1143 /* Clear RS3-RS0 in Control A. */
1144 ctrla &= ~(RTC_CTRL_A_RS_MASK);
1145
1146 /*
1147 * All done with Control A. Switch to Bank 1 for the remainder of
1148 * the RTC setup so we have access to the extended functions.
1149 */
1150 ctrla |= RTC_CTRL_A_DV0;
1151 rtc->write(rtc, RTC_CTRL_A, ctrla);
1152
1153 /* Default to 32768kHz output. */
1154 rtc->write(rtc, RTC_EXT_CTRL_4B,
1155 (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_E32K));
1156
1157 /* Set the SET bit in Control B so we can do some housekeeping. */
1158 rtc->write(rtc, RTC_CTRL_B,
1159 (rtc->read(rtc, RTC_CTRL_B) | RTC_CTRL_B_SET));
1160
1161 /* Read Ext Ctrl 4A and check the INCR bit to avoid a lockout. */
1162 while (rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_INCR)
1163 cpu_relax();
1164
1165 /*
1166 * If the platform supports BCD mode, then set DM=0 in Control B.
1167 * Otherwise, set DM=1 for BIN mode.
1168 */
1169 ctrlb = rtc->read(rtc, RTC_CTRL_B);
1170 if (pdata->bcd_mode)
1171 ctrlb &= ~(RTC_CTRL_B_DM);
1172 else
1173 ctrlb |= RTC_CTRL_B_DM;
1174 rtc->bcd_mode = pdata->bcd_mode;
1175
1176 /*
1177 * Disable Daylight Savings Time (DSE = 0).
1178 * The RTC has hardcoded timezone information that is rendered
1179 * obselete. We'll let the OS deal with DST settings instead.
1180 */
1181 if (ctrlb & RTC_CTRL_B_DSE)
1182 ctrlb &= ~(RTC_CTRL_B_DSE);
1183
1184 /* Force 24-hour mode (2412 = 1). */
1185 if (!(ctrlb & RTC_CTRL_B_2412)) {
1186 /* Reinitialize the time hours. */
1187 hours = rtc->read(rtc, RTC_HRS);
1188 am_pm = hours & RTC_HRS_AMPM_MASK;
1189 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1190 RTC_HRS_12_BIN_MASK);
1191 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1192
1193 /* Enable 24-hour mode. */
1194 ctrlb |= RTC_CTRL_B_2412;
1195
1196 /* Write back to Control B, including DM & DSE bits. */
1197 rtc->write(rtc, RTC_CTRL_B, ctrlb);
1198
1199 /* Write the time hours back. */
1200 rtc->write(rtc, RTC_HRS,
1201 ds1685_rtc_bin2bcd(rtc, hours,
1202 RTC_HRS_24_BIN_MASK,
1203 RTC_HRS_24_BCD_MASK));
1204
1205 /* Reinitialize the alarm hours. */
1206 hours = rtc->read(rtc, RTC_HRS_ALARM);
1207 am_pm = hours & RTC_HRS_AMPM_MASK;
1208 hours = ds1685_rtc_bcd2bin(rtc, hours, RTC_HRS_12_BCD_MASK,
1209 RTC_HRS_12_BIN_MASK);
1210 hours = ((hours == 12) ? 0 : ((am_pm) ? hours + 12 : hours));
1211
1212 /* Write the alarm hours back. */
1213 rtc->write(rtc, RTC_HRS_ALARM,
1214 ds1685_rtc_bin2bcd(rtc, hours,
1215 RTC_HRS_24_BIN_MASK,
1216 RTC_HRS_24_BCD_MASK));
1217 } else {
1218 /* 24-hour mode is already set, so write Control B back. */
1219 rtc->write(rtc, RTC_CTRL_B, ctrlb);
1220 }
1221
1222 /* Unset the SET bit in Control B so the RTC can update. */
1223 rtc->write(rtc, RTC_CTRL_B,
1224 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_SET)));
1225
1226 /* Check the main battery. */
1227 if (!(rtc->read(rtc, RTC_CTRL_D) & RTC_CTRL_D_VRT))
1228 dev_warn(&pdev->dev,
1229 "Main battery is exhausted! RTC may be invalid!\n");
1230
1231 /* Check the auxillary battery. It is optional. */
1232 if (!(rtc->read(rtc, RTC_EXT_CTRL_4A) & RTC_CTRL_4A_VRT2))
1233 dev_warn(&pdev->dev,
1234 "Aux battery is exhausted or not available.\n");
1235
1236 /* Read Ctrl B and clear PIE/AIE/UIE. */
1237 rtc->write(rtc, RTC_CTRL_B,
1238 (rtc->read(rtc, RTC_CTRL_B) & ~(RTC_CTRL_B_PAU_MASK)));
1239
1240 /* Reading Ctrl C auto-clears PF/AF/UF. */
1241 rtc->read(rtc, RTC_CTRL_C);
1242
1243 /* Read Ctrl 4B and clear RIE/WIE/KSE. */
1244 rtc->write(rtc, RTC_EXT_CTRL_4B,
1245 (rtc->read(rtc, RTC_EXT_CTRL_4B) & ~(RTC_CTRL_4B_RWK_MASK)));
1246
1247 /* Clear RF/WF/KF in Ctrl 4A. */
1248 rtc->write(rtc, RTC_EXT_CTRL_4A,
1249 (rtc->read(rtc, RTC_EXT_CTRL_4A) & ~(RTC_CTRL_4A_RWK_MASK)));
1250
1251 /*
1252 * Re-enable KSE to handle power button events. We do not enable
1253 * WIE or RIE by default.
1254 */
1255 rtc->write(rtc, RTC_EXT_CTRL_4B,
1256 (rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_KSE));
1257
1258 rtc_dev = devm_rtc_allocate_device(&pdev->dev);
1259 if (IS_ERR(rtc_dev))
1260 return PTR_ERR(rtc_dev);
1261
1262 rtc_dev->ops = &ds1685_rtc_ops;
1263
1264 /* Century bit is useless because leap year fails in 1900 and 2100 */
1265 rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
1266 rtc_dev->range_max = RTC_TIMESTAMP_END_2099;
1267
1268 /* Maximum periodic rate is 8192Hz (0.122070ms). */
1269 rtc_dev->max_user_freq = RTC_MAX_USER_FREQ;
1270
1271 /* See if the platform doesn't support UIE. */
1272 if (pdata->uie_unsupported)
1273 rtc_dev->uie_unsupported = 1;
1274 rtc->uie_unsupported = pdata->uie_unsupported;
1275
1276 rtc->dev = rtc_dev;
1277
1278 /*
1279 * Fetch the IRQ and setup the interrupt handler.
1280 *
1281 * Not all platforms have the IRQF pin tied to something. If not, the
1282 * RTC will still set the *IE / *F flags and raise IRQF in ctrlc, but
1283 * there won't be an automatic way of notifying the kernel about it,
1284 * unless ctrlc is explicitly polled.
1285 */
1286 if (!pdata->no_irq) {
1287 ret = platform_get_irq(pdev, 0);
1288 if (ret <= 0)
1289 return ret;
1290
1291 rtc->irq_num = ret;
1292
1293 /* Request an IRQ. */
1294 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq_num,
1295 NULL, ds1685_rtc_irq_handler,
1296 IRQF_SHARED | IRQF_ONESHOT,
1297 pdev->name, pdev);
1298
1299 /* Check to see if something came back. */
1300 if (unlikely(ret)) {
1301 dev_warn(&pdev->dev,
1302 "RTC interrupt not available\n");
1303 rtc->irq_num = 0;
1304 }
1305 }
1306 rtc->no_irq = pdata->no_irq;
1307
1308 /* Setup complete. */
1309 ds1685_rtc_switch_to_bank0(rtc);
1310
1311 ret = rtc_add_group(rtc_dev, &ds1685_rtc_sysfs_misc_grp);
1312 if (ret)
1313 return ret;
1314
1315 rtc_dev->nvram_old_abi = true;
1316 nvmem_cfg.priv = rtc;
1317 ret = rtc_nvmem_register(rtc_dev, &nvmem_cfg);
1318 if (ret)
1319 return ret;
1320
1321 return rtc_register_device(rtc_dev);
1322}
1323
1324/**
1325 * ds1685_rtc_remove - removes rtc driver.
1326 * @pdev: pointer to platform_device structure.
1327 */
1328static int
1329ds1685_rtc_remove(struct platform_device *pdev)
1330{
1331 struct ds1685_priv *rtc = platform_get_drvdata(pdev);
1332
1333 /* Read Ctrl B and clear PIE/AIE/UIE. */
1334 rtc->write(rtc, RTC_CTRL_B,
1335 (rtc->read(rtc, RTC_CTRL_B) &
1336 ~(RTC_CTRL_B_PAU_MASK)));
1337
1338 /* Reading Ctrl C auto-clears PF/AF/UF. */
1339 rtc->read(rtc, RTC_CTRL_C);
1340
1341 /* Read Ctrl 4B and clear RIE/WIE/KSE. */
1342 rtc->write(rtc, RTC_EXT_CTRL_4B,
1343 (rtc->read(rtc, RTC_EXT_CTRL_4B) &
1344 ~(RTC_CTRL_4B_RWK_MASK)));
1345
1346 /* Manually clear RF/WF/KF in Ctrl 4A. */
1347 rtc->write(rtc, RTC_EXT_CTRL_4A,
1348 (rtc->read(rtc, RTC_EXT_CTRL_4A) &
1349 ~(RTC_CTRL_4A_RWK_MASK)));
1350
1351 return 0;
1352}
1353
1354/**
1355 * ds1685_rtc_driver - rtc driver properties.
1356 */
1357static struct platform_driver ds1685_rtc_driver = {
1358 .driver = {
1359 .name = "rtc-ds1685",
1360 },
1361 .probe = ds1685_rtc_probe,
1362 .remove = ds1685_rtc_remove,
1363};
1364module_platform_driver(ds1685_rtc_driver);
1365/* ----------------------------------------------------------------------- */
1366
1367
1368/* ----------------------------------------------------------------------- */
1369/* Poweroff function */
1370
1371/**
1372 * ds1685_rtc_poweroff - uses the RTC chip to power the system off.
1373 * @pdev: pointer to platform_device structure.
1374 */
1375void __noreturn
1376ds1685_rtc_poweroff(struct platform_device *pdev)
1377{
1378 u8 ctrla, ctrl4a, ctrl4b;
1379 struct ds1685_priv *rtc;
1380
1381 /* Check for valid RTC data, else, spin forever. */
1382 if (unlikely(!pdev)) {
1383 pr_emerg("platform device data not available, spinning forever ...\n");
1384 while(1);
1385 unreachable();
1386 } else {
1387 /* Get the rtc data. */
1388 rtc = platform_get_drvdata(pdev);
1389
1390 /*
1391 * Disable our IRQ. We're powering down, so we're not
1392 * going to worry about cleaning up. Most of that should
1393 * have been taken care of by the shutdown scripts and this
1394 * is the final function call.
1395 */
1396 if (!rtc->no_irq)
1397 disable_irq_nosync(rtc->irq_num);
1398
1399 /* Oscillator must be on and the countdown chain enabled. */
1400 ctrla = rtc->read(rtc, RTC_CTRL_A);
1401 ctrla |= RTC_CTRL_A_DV1;
1402 ctrla &= ~(RTC_CTRL_A_DV2);
1403 rtc->write(rtc, RTC_CTRL_A, ctrla);
1404
1405 /*
1406 * Read Control 4A and check the status of the auxillary
1407 * battery. This must be present and working (VRT2 = 1)
1408 * for wakeup and kickstart functionality to be useful.
1409 */
1410 ds1685_rtc_switch_to_bank1(rtc);
1411 ctrl4a = rtc->read(rtc, RTC_EXT_CTRL_4A);
1412 if (ctrl4a & RTC_CTRL_4A_VRT2) {
1413 /* Clear all of the interrupt flags on Control 4A. */
1414 ctrl4a &= ~(RTC_CTRL_4A_RWK_MASK);
1415 rtc->write(rtc, RTC_EXT_CTRL_4A, ctrl4a);
1416
1417 /*
1418 * The auxillary battery is present and working.
1419 * Enable extended functions (ABE=1), enable
1420 * wake-up (WIE=1), and enable kickstart (KSE=1)
1421 * in Control 4B.
1422 */
1423 ctrl4b = rtc->read(rtc, RTC_EXT_CTRL_4B);
1424 ctrl4b |= (RTC_CTRL_4B_ABE | RTC_CTRL_4B_WIE |
1425 RTC_CTRL_4B_KSE);
1426 rtc->write(rtc, RTC_EXT_CTRL_4B, ctrl4b);
1427 }
1428
1429 /* Set PAB to 1 in Control 4A to power the system down. */
1430 dev_warn(&pdev->dev, "Powerdown.\n");
1431 msleep(20);
1432 rtc->write(rtc, RTC_EXT_CTRL_4A,
1433 (ctrl4a | RTC_CTRL_4A_PAB));
1434
1435 /* Spin ... we do not switch back to bank0. */
1436 while(1);
1437 unreachable();
1438 }
1439}
1440EXPORT_SYMBOL(ds1685_rtc_poweroff);
1441/* ----------------------------------------------------------------------- */
1442
1443
1444MODULE_AUTHOR("Joshua Kinard <kumba@gentoo.org>");
1445MODULE_AUTHOR("Matthias Fuchs <matthias.fuchs@esd-electronics.com>");
1446MODULE_DESCRIPTION("Dallas/Maxim DS1685/DS1687-series RTC driver");
1447MODULE_LICENSE("GPL");
1448MODULE_ALIAS("platform:rtc-ds1685");