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Merge tag 'char-misc-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...
[mirror_ubuntu-jammy-kernel.git] / drivers / rtc / rtc-ab-b5ze-s3.c
CommitLineData
0b2f6228
AE		 1/*
2 * rtc-ab-b5ze-s3 - Driver for Abracon AB-RTCMC-32.768Khz-B5ZE-S3
3 * I2C RTC / Alarm chip
4 *
5 * Copyright (C) 2014, Arnaud EBALARD <arno@natisbad.org>
6 *
7 * Detailed datasheet of the chip is available here:
8 *
9 * http://www.abracon.com/realtimeclock/AB-RTCMC-32.768kHz-B5ZE-S3-Application-Manual.pdf
10 *
11 * This work is based on ISL12057 driver (drivers/rtc/rtc-isl12057.c).
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 */
23
24#include <linux/module.h>
25#include <linux/mutex.h>
26#include <linux/rtc.h>
27#include <linux/i2c.h>
28#include <linux/bcd.h>
29#include <linux/of.h>
30#include <linux/regmap.h>
31#include <linux/interrupt.h>
32
33#define DRV_NAME "rtc-ab-b5ze-s3"
34
35/* Control section */
36#define ABB5ZES3_REG_CTRL1 0x00 /* Control 1 register */
37#define ABB5ZES3_REG_CTRL1_CIE BIT(0) /* Pulse interrupt enable */
38#define ABB5ZES3_REG_CTRL1_AIE BIT(1) /* Alarm interrupt enable */
39#define ABB5ZES3_REG_CTRL1_SIE BIT(2) /* Second interrupt enable */
40#define ABB5ZES3_REG_CTRL1_PM BIT(3) /* 24h/12h mode */
41#define ABB5ZES3_REG_CTRL1_SR BIT(4) /* Software reset */
42#define ABB5ZES3_REG_CTRL1_STOP BIT(5) /* RTC circuit enable */
43#define ABB5ZES3_REG_CTRL1_CAP BIT(7)
44
45#define ABB5ZES3_REG_CTRL2 0x01 /* Control 2 register */
46#define ABB5ZES3_REG_CTRL2_CTBIE BIT(0) /* Countdown timer B int. enable */
47#define ABB5ZES3_REG_CTRL2_CTAIE BIT(1) /* Countdown timer A int. enable */
48#define ABB5ZES3_REG_CTRL2_WTAIE BIT(2) /* Watchdog timer A int. enable */
49#define ABB5ZES3_REG_CTRL2_AF BIT(3) /* Alarm interrupt status */
50#define ABB5ZES3_REG_CTRL2_SF BIT(4) /* Second interrupt status */
51#define ABB5ZES3_REG_CTRL2_CTBF BIT(5) /* Countdown timer B int. status */
52#define ABB5ZES3_REG_CTRL2_CTAF BIT(6) /* Countdown timer A int. status */
53#define ABB5ZES3_REG_CTRL2_WTAF BIT(7) /* Watchdog timer A int. status */
54
55#define ABB5ZES3_REG_CTRL3 0x02 /* Control 3 register */
56#define ABB5ZES3_REG_CTRL3_PM2 BIT(7) /* Power Management bit 2 */
57#define ABB5ZES3_REG_CTRL3_PM1 BIT(6) /* Power Management bit 1 */
58#define ABB5ZES3_REG_CTRL3_PM0 BIT(5) /* Power Management bit 0 */
59#define ABB5ZES3_REG_CTRL3_BSF BIT(3) /* Battery switchover int. status */
60#define ABB5ZES3_REG_CTRL3_BLF BIT(2) /* Battery low int. status */
61#define ABB5ZES3_REG_CTRL3_BSIE BIT(1) /* Battery switchover int. enable */
62#define ABB5ZES3_REG_CTRL3_BLIE BIT(0) /* Battery low int. enable */
63
64#define ABB5ZES3_CTRL_SEC_LEN 3
65
66/* RTC section */
67#define ABB5ZES3_REG_RTC_SC 0x03 /* RTC Seconds register */
68#define ABB5ZES3_REG_RTC_SC_OSC BIT(7) /* Clock integrity status */
69#define ABB5ZES3_REG_RTC_MN 0x04 /* RTC Minutes register */
70#define ABB5ZES3_REG_RTC_HR 0x05 /* RTC Hours register */
71#define ABB5ZES3_REG_RTC_HR_PM BIT(5) /* RTC Hours PM bit */
72#define ABB5ZES3_REG_RTC_DT 0x06 /* RTC Date register */
73#define ABB5ZES3_REG_RTC_DW 0x07 /* RTC Day of the week register */
74#define ABB5ZES3_REG_RTC_MO 0x08 /* RTC Month register */
75#define ABB5ZES3_REG_RTC_YR 0x09 /* RTC Year register */
76
77#define ABB5ZES3_RTC_SEC_LEN 7
78
79/* Alarm section (enable bits are all active low) */
80#define ABB5ZES3_REG_ALRM_MN 0x0A /* Alarm - minute register */
81#define ABB5ZES3_REG_ALRM_MN_AE BIT(7) /* Minute enable */
82#define ABB5ZES3_REG_ALRM_HR 0x0B /* Alarm - hours register */
83#define ABB5ZES3_REG_ALRM_HR_AE BIT(7) /* Hour enable */
84#define ABB5ZES3_REG_ALRM_DT 0x0C /* Alarm - date register */
85#define ABB5ZES3_REG_ALRM_DT_AE BIT(7) /* Date (day of the month) enable */
86#define ABB5ZES3_REG_ALRM_DW 0x0D /* Alarm - day of the week reg. */
87#define ABB5ZES3_REG_ALRM_DW_AE BIT(7) /* Day of the week enable */
88
89#define ABB5ZES3_ALRM_SEC_LEN 4
90
91/* Frequency offset section */
92#define ABB5ZES3_REG_FREQ_OF 0x0E /* Frequency offset register */
93#define ABB5ZES3_REG_FREQ_OF_MODE 0x0E /* Offset mode: 2 hours / minute */
94
95/* CLOCKOUT section */
96#define ABB5ZES3_REG_TIM_CLK 0x0F /* Timer & Clockout register */
97#define ABB5ZES3_REG_TIM_CLK_TAM BIT(7) /* Permanent/pulsed timer A/int. 2 */
98#define ABB5ZES3_REG_TIM_CLK_TBM BIT(6) /* Permanent/pulsed timer B */
99#define ABB5ZES3_REG_TIM_CLK_COF2 BIT(5) /* Clkout Freq bit 2 */
100#define ABB5ZES3_REG_TIM_CLK_COF1 BIT(4) /* Clkout Freq bit 1 */
101#define ABB5ZES3_REG_TIM_CLK_COF0 BIT(3) /* Clkout Freq bit 0 */
102#define ABB5ZES3_REG_TIM_CLK_TAC1 BIT(2) /* Timer A: - 01 : countdown */
103#define ABB5ZES3_REG_TIM_CLK_TAC0 BIT(1) /* - 10 : timer */
104#define ABB5ZES3_REG_TIM_CLK_TBC BIT(0) /* Timer B enable */
105
106/* Timer A Section */
107#define ABB5ZES3_REG_TIMA_CLK 0x10 /* Timer A clock register */
108#define ABB5ZES3_REG_TIMA_CLK_TAQ2 BIT(2) /* Freq bit 2 */
109#define ABB5ZES3_REG_TIMA_CLK_TAQ1 BIT(1) /* Freq bit 1 */
110#define ABB5ZES3_REG_TIMA_CLK_TAQ0 BIT(0) /* Freq bit 0 */
111#define ABB5ZES3_REG_TIMA 0x11 /* Timer A register */
112
113#define ABB5ZES3_TIMA_SEC_LEN 2
114
115/* Timer B Section */
116#define ABB5ZES3_REG_TIMB_CLK 0x12 /* Timer B clock register */
117#define ABB5ZES3_REG_TIMB_CLK_TBW2 BIT(6)
118#define ABB5ZES3_REG_TIMB_CLK_TBW1 BIT(5)
119#define ABB5ZES3_REG_TIMB_CLK_TBW0 BIT(4)
120#define ABB5ZES3_REG_TIMB_CLK_TAQ2 BIT(2)
121#define ABB5ZES3_REG_TIMB_CLK_TAQ1 BIT(1)
122#define ABB5ZES3_REG_TIMB_CLK_TAQ0 BIT(0)
123#define ABB5ZES3_REG_TIMB 0x13 /* Timer B register */
124#define ABB5ZES3_TIMB_SEC_LEN 2
125
126#define ABB5ZES3_MEM_MAP_LEN 0x14
127
128struct abb5zes3_rtc_data {
129 struct rtc_device *rtc;
130 struct regmap *regmap;
131 struct mutex lock;
132
133 int irq;
134
135 bool battery_low;
c8a1d8a5 136 bool timer_alarm; /* current alarm is via timer A */
0b2f6228
AE		 137};
138
139/*
140 * Try and match register bits w/ fixed null values to see whether we
141 * are dealing with an ABB5ZES3. Note: this function is called early
142 * during init and hence does need mutex protection.
143 */
144static int abb5zes3_i2c_validate_chip(struct regmap *regmap)
145{
146 u8 regs[ABB5ZES3_MEM_MAP_LEN];
147 static const u8 mask[ABB5ZES3_MEM_MAP_LEN] = { 0x00, 0x00, 0x10, 0x00,
148 0x80, 0xc0, 0xc0, 0xf8,
149 0xe0, 0x00, 0x00, 0x40,
150 0x40, 0x78, 0x00, 0x00,
151 0xf8, 0x00, 0x88, 0x00 };
152 int ret, i;
153
154 ret = regmap_bulk_read(regmap, 0, regs, ABB5ZES3_MEM_MAP_LEN);
155 if (ret)
156 return ret;
157
158 for (i = 0; i < ABB5ZES3_MEM_MAP_LEN; ++i) {
159 if (regs[i] & mask[i]) /* check if bits are cleared */
160 return -ENODEV;
161 }
162
163 return 0;
164}
165
166/* Clear alarm status bit. */
167static int _abb5zes3_rtc_clear_alarm(struct device *dev)
168{
169 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
170 int ret;
171
172 ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2,
173 ABB5ZES3_REG_CTRL2_AF, 0);
174 if (ret)
175 dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
176
177 return ret;
178}
179
180/* Enable or disable alarm (i.e. alarm interrupt generation) */
181static int _abb5zes3_rtc_update_alarm(struct device *dev, bool enable)
182{
183 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
184 int ret;
185
186 ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL1,
187 ABB5ZES3_REG_CTRL1_AIE,
188 enable ? ABB5ZES3_REG_CTRL1_AIE : 0);
189 if (ret)
190 dev_err(dev, "%s: writing alarm INT failed (%d)\n",
191 __func__, ret);
192
193 return ret;
194}
195
c8a1d8a5
AE		 196/* Enable or disable timer (watchdog timer A interrupt generation) */
197static int _abb5zes3_rtc_update_timer(struct device *dev, bool enable)
198{
199 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
200 int ret;
201
202 ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2,
203 ABB5ZES3_REG_CTRL2_WTAIE,
204 enable ? ABB5ZES3_REG_CTRL2_WTAIE : 0);
205 if (ret)
206 dev_err(dev, "%s: writing timer INT failed (%d)\n",
207 __func__, ret);
208
209 return ret;
210}
211
0b2f6228
AE		 212/*
213 * Note: we only read, so regmap inner lock protection is sufficient, i.e.
214 * we do not need driver's main lock protection.
215 */
216static int _abb5zes3_rtc_read_time(struct device *dev, struct rtc_time *tm)
217{
218 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
219 u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN];
ce2e5a76 220 int ret = 0;
0b2f6228
AE		 221
222 /*
223 * As we need to read CTRL1 register anyway to access 24/12h
224 * mode bit, we do a single bulk read of both control and RTC
225 * sections (they are consecutive). This also ease indexing
226 * of register values after bulk read.
227 */
228 ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_CTRL1, regs,
229 sizeof(regs));
230 if (ret) {
231 dev_err(dev, "%s: reading RTC time failed (%d)\n",
232 __func__, ret);
233 goto err;
234 }
235
236 /* If clock integrity is not guaranteed, do not return a time value */
237 if (regs[ABB5ZES3_REG_RTC_SC] & ABB5ZES3_REG_RTC_SC_OSC) {
238 ret = -ENODATA;
239 goto err;
240 }
241
242 tm->tm_sec = bcd2bin(regs[ABB5ZES3_REG_RTC_SC] & 0x7F);
243 tm->tm_min = bcd2bin(regs[ABB5ZES3_REG_RTC_MN]);
244
245 if (regs[ABB5ZES3_REG_CTRL1] & ABB5ZES3_REG_CTRL1_PM) { /* 12hr mode */
246 tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR] & 0x1f);
247 if (regs[ABB5ZES3_REG_RTC_HR] & ABB5ZES3_REG_RTC_HR_PM) /* PM */
248 tm->tm_hour += 12;
249 } else { /* 24hr mode */
250 tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR]);
251 }
252
253 tm->tm_mday = bcd2bin(regs[ABB5ZES3_REG_RTC_DT]);
254 tm->tm_wday = bcd2bin(regs[ABB5ZES3_REG_RTC_DW]);
255 tm->tm_mon = bcd2bin(regs[ABB5ZES3_REG_RTC_MO]) - 1; /* starts at 1 */
256 tm->tm_year = bcd2bin(regs[ABB5ZES3_REG_RTC_YR]) + 100;
257
0b2f6228
AE		 258err:
259 return ret;
260}
261
262static int abb5zes3_rtc_set_time(struct device *dev, struct rtc_time *tm)
263{
264 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
265 u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN];
266 int ret;
267
268 /*
269 * Year register is 8-bit wide and bcd-coded, i.e records values
270 * between 0 and 99. tm_year is an offset from 1900 and we are
271 * interested in the 2000-2099 range, so any value less than 100
272 * is invalid.
273 */
274 if (tm->tm_year < 100)
275 return -EINVAL;
276
277 regs[ABB5ZES3_REG_RTC_SC] = bin2bcd(tm->tm_sec); /* MSB=0 clears OSC */
278 regs[ABB5ZES3_REG_RTC_MN] = bin2bcd(tm->tm_min);
279 regs[ABB5ZES3_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
280 regs[ABB5ZES3_REG_RTC_DT] = bin2bcd(tm->tm_mday);
281 regs[ABB5ZES3_REG_RTC_DW] = bin2bcd(tm->tm_wday);
282 regs[ABB5ZES3_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1);
283 regs[ABB5ZES3_REG_RTC_YR] = bin2bcd(tm->tm_year - 100);
284
285 mutex_lock(&data->lock);
286 ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_RTC_SC,
287 regs + ABB5ZES3_REG_RTC_SC,
288 ABB5ZES3_RTC_SEC_LEN);
289 mutex_unlock(&data->lock);
290
291
292 return ret;
293}
294
c8a1d8a5
AE		 295/*
296 * Set provided TAQ and Timer A registers (TIMA_CLK and TIMA) based on
297 * given number of seconds.
298 */
299static inline void sec_to_timer_a(u8 secs, u8 *taq, u8 *timer_a)
300{
301 *taq = ABB5ZES3_REG_TIMA_CLK_TAQ1; /* 1Hz */
302 *timer_a = secs;
303}
304
305/*
306 * Return current number of seconds in Timer A. As we only use
307 * timer A with a 1Hz freq, this is what we expect to have.
308 */
309static inline int sec_from_timer_a(u8 *secs, u8 taq, u8 timer_a)
310{
311 if (taq != ABB5ZES3_REG_TIMA_CLK_TAQ1) /* 1Hz */
312 return -EINVAL;
313
314 *secs = timer_a;
315
316 return 0;
317}
318
319/*
320 * Read alarm currently configured via a watchdog timer using timer A. This
321 * is done by reading current RTC time and adding remaining timer time.
322 */
323static int _abb5zes3_rtc_read_timer(struct device *dev,
324 struct rtc_wkalrm *alarm)
325{
326 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
327 struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
328 u8 regs[ABB5ZES3_TIMA_SEC_LEN + 1];
329 unsigned long rtc_secs;
330 unsigned int reg;
331 u8 timer_secs;
332 int ret;
333
334 /*
335 * Instead of doing two separate calls, because they are consecutive,
336 * we grab both clockout register and Timer A section. The latter is
337 * used to decide if timer A is enabled (as a watchdog timer).
338 */
339 ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_TIM_CLK, regs,
340 ABB5ZES3_TIMA_SEC_LEN + 1);
341 if (ret) {
342 dev_err(dev, "%s: reading Timer A section failed (%d)\n",
343 __func__, ret);
344 goto err;
345 }
346
347 /* get current time ... */
348 ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
349 if (ret)
350 goto err;
351
352 /* ... convert to seconds ... */
353 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
354 if (ret)
355 goto err;
356
357 /* ... add remaining timer A time ... */
358 ret = sec_from_timer_a(&timer_secs, regs[1], regs[2]);
359 if (ret)
360 goto err;
361
362 /* ... and convert back. */
363 rtc_time_to_tm(rtc_secs + timer_secs, alarm_tm);
364
365 ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL2, &reg);
366 if (ret) {
367 dev_err(dev, "%s: reading ctrl reg failed (%d)\n",
368 __func__, ret);
369 goto err;
370 }
371
372 alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL2_WTAIE);
373
374err:
375 return ret;
376}
377
378/* Read alarm currently configured via a RTC alarm registers. */
379static int _abb5zes3_rtc_read_alarm(struct device *dev,
380 struct rtc_wkalrm *alarm)
0b2f6228
AE		 381{
382 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
383 struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
384 unsigned long rtc_secs, alarm_secs;
385 u8 regs[ABB5ZES3_ALRM_SEC_LEN];
386 unsigned int reg;
387 int ret;
388
0b2f6228
AE		 389 ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_ALRM_MN, regs,
390 ABB5ZES3_ALRM_SEC_LEN);
391 if (ret) {
392 dev_err(dev, "%s: reading alarm section failed (%d)\n",
393 __func__, ret);
394 goto err;
395 }
396
397 alarm_tm->tm_sec = 0;
398 alarm_tm->tm_min = bcd2bin(regs[0] & 0x7f);
399 alarm_tm->tm_hour = bcd2bin(regs[1] & 0x3f);
400 alarm_tm->tm_mday = bcd2bin(regs[2] & 0x3f);
401 alarm_tm->tm_wday = -1;
402
403 /*
404 * The alarm section does not store year/month. We use the ones in rtc
405 * section as a basis and increment month and then year if needed to get
406 * alarm after current time.
407 */
408 ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
409 if (ret)
410 goto err;
411
412 alarm_tm->tm_year = rtc_tm.tm_year;
413 alarm_tm->tm_mon = rtc_tm.tm_mon;
414
415 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
416 if (ret)
417 goto err;
418
419 ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
420 if (ret)
421 goto err;
422
423 if (alarm_secs < rtc_secs) {
424 if (alarm_tm->tm_mon == 11) {
425 alarm_tm->tm_mon = 0;
426 alarm_tm->tm_year += 1;
427 } else {
428 alarm_tm->tm_mon += 1;
429 }
430 }
431
432 ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL1, &reg);
433 if (ret) {
434 dev_err(dev, "%s: reading ctrl reg failed (%d)\n",
435 __func__, ret);
436 goto err;
437 }
438
439 alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL1_AIE);
440
441err:
c8a1d8a5
AE		 442 return ret;
443}
444
445/*
446 * As the Alarm mechanism supported by the chip is only accurate to the
447 * minute, we use the watchdog timer mechanism provided by timer A
448 * (up to 256 seconds w/ a second accuracy) for low alarm values (below
449 * 4 minutes). Otherwise, we use the common alarm mechanism provided
450 * by the chip. In order for that to work, we keep track of currently
451 * configured timer type via 'timer_alarm' flag in our private data
452 * structure.
453 */
454static int abb5zes3_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
455{
456 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
457 int ret;
458
459 mutex_lock(&data->lock);
460 if (data->timer_alarm)
461 ret = _abb5zes3_rtc_read_timer(dev, alarm);
462 else
463 ret = _abb5zes3_rtc_read_alarm(dev, alarm);
0b2f6228
AE		 464 mutex_unlock(&data->lock);
465
466 return ret;
467}
468
c8a1d8a5
AE		 469/*
470 * Set alarm using chip alarm mechanism. It is only accurate to the
471 * minute (not the second). The function expects alarm interrupt to
472 * be disabled.
473 */
474static int _abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
0b2f6228
AE		 475{
476 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
477 struct rtc_time *alarm_tm = &alarm->time;
478 unsigned long rtc_secs, alarm_secs;
479 u8 regs[ABB5ZES3_ALRM_SEC_LEN];
480 struct rtc_time rtc_tm;
481 int ret, enable = 1;
482
0b2f6228
AE		 483 ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
484 if (ret)
485 goto err;
486
487 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
488 if (ret)
489 goto err;
490
491 ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
492 if (ret)
493 goto err;
494
495 /* If alarm time is before current time, disable the alarm */
496 if (!alarm->enabled || alarm_secs <= rtc_secs) {
497 enable = 0;
498 } else {
499 /*
500 * Chip only support alarms up to one month in the future. Let's
501 * return an error if we get something after that limit.
502 * Comparison is done by incrementing rtc_tm month field by one
503 * and checking alarm value is still below.
504 */
505 if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
506 rtc_tm.tm_mon = 0;
507 rtc_tm.tm_year += 1;
508 } else {
509 rtc_tm.tm_mon += 1;
510 }
511
512 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
513 if (ret)
514 goto err;
515
516 if (alarm_secs > rtc_secs) {
517 dev_err(dev, "%s: alarm maximum is one month in the "
518 "future (%d)\n", __func__, ret);
519 ret = -EINVAL;
520 goto err;
521 }
522 }
523
c8a1d8a5
AE		 524 /*
525 * Program all alarm registers but DW one. For each register, setting
526 * MSB to 0 enables associated alarm.
527 */
528 regs[0] = bin2bcd(alarm_tm->tm_min) & 0x7f;
529 regs[1] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
530 regs[2] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
0b2f6228
AE		 531 regs[3] = ABB5ZES3_REG_ALRM_DW_AE; /* do not match day of the week */
532
533 ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_ALRM_MN, regs,
534 ABB5ZES3_ALRM_SEC_LEN);
535 if (ret < 0) {
536 dev_err(dev, "%s: writing ALARM section failed (%d)\n",
537 __func__, ret);
538 goto err;
539 }
540
c8a1d8a5
AE		 541 /* Record currently configured alarm is not a timer */
542 data->timer_alarm = 0;
543
544 /* Enable or disable alarm interrupt generation */
0b2f6228
AE		 545 ret = _abb5zes3_rtc_update_alarm(dev, enable);
546
547err:
c8a1d8a5
AE		 548 return ret;
549}
550
551/*
552 * Set alarm using timer watchdog (via timer A) mechanism. The function expects
553 * timer A interrupt to be disabled.
554 */
555static int _abb5zes3_rtc_set_timer(struct device *dev, struct rtc_wkalrm *alarm,
556 u8 secs)
557{
558 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
559 u8 regs[ABB5ZES3_TIMA_SEC_LEN];
560 u8 mask = ABB5ZES3_REG_TIM_CLK_TAC0 | ABB5ZES3_REG_TIM_CLK_TAC1;
561 int ret = 0;
562
563 /* Program given number of seconds to Timer A registers */
564 sec_to_timer_a(secs, &regs[0], &regs[1]);
565 ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_TIMA_CLK, regs,
566 ABB5ZES3_TIMA_SEC_LEN);
567 if (ret < 0) {
568 dev_err(dev, "%s: writing timer section failed\n", __func__);
569 goto err;
570 }
571
572 /* Configure Timer A as a watchdog timer */
573 ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_TIM_CLK,
574 mask, ABB5ZES3_REG_TIM_CLK_TAC1);
575 if (ret)
576 dev_err(dev, "%s: failed to update timer\n", __func__);
577
578 /* Record currently configured alarm is a timer */
579 data->timer_alarm = 1;
0b2f6228 580
c8a1d8a5
AE		 581 /* Enable or disable timer interrupt generation */
582 ret = _abb5zes3_rtc_update_timer(dev, alarm->enabled);
583
584err:
0b2f6228
AE		 585 return ret;
586}
587
c8a1d8a5
AE		 588/*
589 * The chip has an alarm which is only accurate to the minute. In order to
590 * handle alarms below that limit, we use the watchdog timer function of
591 * timer A. More precisely, the timer method is used for alarms below 240
592 * seconds.
593 */
594static int abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
595{
596 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
597 struct rtc_time *alarm_tm = &alarm->time;
598 unsigned long rtc_secs, alarm_secs;
599 struct rtc_time rtc_tm;
600 int ret;
601
602 mutex_lock(&data->lock);
603 ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
604 if (ret)
605 goto err;
606
607 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
608 if (ret)
609 goto err;
610
611 ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
612 if (ret)
613 goto err;
614
615 /* Let's first disable both the alarm and the timer interrupts */
616 ret = _abb5zes3_rtc_update_alarm(dev, false);
617 if (ret < 0) {
618 dev_err(dev, "%s: unable to disable alarm (%d)\n", __func__,
619 ret);
620 goto err;
621 }
622 ret = _abb5zes3_rtc_update_timer(dev, false);
623 if (ret < 0) {
624 dev_err(dev, "%s: unable to disable timer (%d)\n", __func__,
625 ret);
626 goto err;
627 }
628
629 data->timer_alarm = 0;
630
631 /*
632 * Let's now configure the alarm; if we are expected to ring in
633 * more than 240s, then we setup an alarm. Otherwise, a timer.
634 */
635 if ((alarm_secs > rtc_secs) && ((alarm_secs - rtc_secs) <= 240))
636 ret = _abb5zes3_rtc_set_timer(dev, alarm,
637 alarm_secs - rtc_secs);
638 else
639 ret = _abb5zes3_rtc_set_alarm(dev, alarm);
640
641 err:
642 mutex_unlock(&data->lock);
643
644 if (ret)
645 dev_err(dev, "%s: unable to configure alarm (%d)\n", __func__,
646 ret);
647
648 return ret;
447a5647 649}
0b2f6228
AE		 650
651/* Enable or disable battery low irq generation */
652static inline int _abb5zes3_rtc_battery_low_irq_enable(struct regmap *regmap,
653 bool enable)
654{
655 return regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3,
656 ABB5ZES3_REG_CTRL3_BLIE,
657 enable ? ABB5ZES3_REG_CTRL3_BLIE : 0);
658}
659
660/*
661 * Check current RTC status and enable/disable what needs to be. Return 0 if
662 * everything went ok and a negative value upon error. Note: this function
663 * is called early during init and hence does need mutex protection.
664 */
665static int abb5zes3_rtc_check_setup(struct device *dev)
666{
667 struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
c8a1d8a5 668 struct regmap *regmap = data->regmap;
0b2f6228
AE		 669 unsigned int reg;
670 int ret;
671 u8 mask;
672
673 /*
674 * By default, the devices generates a 32.768KHz signal on IRQ#1 pin. It
675 * is disabled here to prevent polluting the interrupt line and
676 * uselessly triggering the IRQ handler we install for alarm and battery
677 * low events. Note: this is done before clearing int. status below
678 * in this function.
679 * We also disable all timers and set timer interrupt to permanent (not
680 * pulsed).
681 */
682 mask = (ABB5ZES3_REG_TIM_CLK_TBC | ABB5ZES3_REG_TIM_CLK_TAC0 |
683 ABB5ZES3_REG_TIM_CLK_TAC1 | ABB5ZES3_REG_TIM_CLK_COF0 |
684 ABB5ZES3_REG_TIM_CLK_COF1 | ABB5ZES3_REG_TIM_CLK_COF2 |
685 ABB5ZES3_REG_TIM_CLK_TBM | ABB5ZES3_REG_TIM_CLK_TAM);
686 ret = regmap_update_bits(regmap, ABB5ZES3_REG_TIM_CLK, mask,
687 ABB5ZES3_REG_TIM_CLK_COF0 | ABB5ZES3_REG_TIM_CLK_COF1 |
688 ABB5ZES3_REG_TIM_CLK_COF2);
689 if (ret < 0) {
690 dev_err(dev, "%s: unable to initialize clkout register (%d)\n",
691 __func__, ret);
692 return ret;
693 }
694
695 /*
696 * Each component of the alarm (MN, HR, DT, DW) can be enabled/disabled
697 * individually by clearing/setting MSB of each associated register. So,
698 * we set all alarm enable bits to disable current alarm setting.
699 */
700 mask = (ABB5ZES3_REG_ALRM_MN_AE | ABB5ZES3_REG_ALRM_HR_AE |
701 ABB5ZES3_REG_ALRM_DT_AE | ABB5ZES3_REG_ALRM_DW_AE);
702 ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, mask);
703 if (ret < 0) {
704 dev_err(dev, "%s: unable to disable alarm setting (%d)\n",
705 __func__, ret);
706 return ret;
707 }
708
709 /* Set Control 1 register (RTC enabled, 24hr mode, all int. disabled) */
710 mask = (ABB5ZES3_REG_CTRL1_CIE | ABB5ZES3_REG_CTRL1_AIE |
711 ABB5ZES3_REG_CTRL1_SIE | ABB5ZES3_REG_CTRL1_PM |
712 ABB5ZES3_REG_CTRL1_CAP | ABB5ZES3_REG_CTRL1_STOP);
713 ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL1, mask, 0);
714 if (ret < 0) {
715 dev_err(dev, "%s: unable to initialize CTRL1 register (%d)\n",
716 __func__, ret);
717 return ret;
718 }
719
720 /*
721 * Set Control 2 register (timer int. disabled, alarm status cleared).
722 * WTAF is read-only and cleared automatically by reading the register.
723 */
724 mask = (ABB5ZES3_REG_CTRL2_CTBIE | ABB5ZES3_REG_CTRL2_CTAIE |
725 ABB5ZES3_REG_CTRL2_WTAIE | ABB5ZES3_REG_CTRL2_AF |
726 ABB5ZES3_REG_CTRL2_SF | ABB5ZES3_REG_CTRL2_CTBF |
727 ABB5ZES3_REG_CTRL2_CTAF);
728 ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, 0);
729 if (ret < 0) {
730 dev_err(dev, "%s: unable to initialize CTRL2 register (%d)\n",
731 __func__, ret);
732 return ret;
733 }
734
735 /*
736 * Enable battery low detection function and battery switchover function
737 * (standard mode). Disable associated interrupts. Clear battery
738 * switchover flag but not battery low flag. The latter is checked
739 * later below.
740 */
741 mask = (ABB5ZES3_REG_CTRL3_PM0 | ABB5ZES3_REG_CTRL3_PM1 |
742 ABB5ZES3_REG_CTRL3_PM2 | ABB5ZES3_REG_CTRL3_BLIE |
743 ABB5ZES3_REG_CTRL3_BSIE| ABB5ZES3_REG_CTRL3_BSF);
744 ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3, mask, 0);
745 if (ret < 0) {
746 dev_err(dev, "%s: unable to initialize CTRL3 register (%d)\n",
747 __func__, ret);
748 return ret;
749 }
750
751 /* Check oscillator integrity flag */
752 ret = regmap_read(regmap, ABB5ZES3_REG_RTC_SC, &reg);
753 if (ret < 0) {
754 dev_err(dev, "%s: unable to read osc. integrity flag (%d)\n",
755 __func__, ret);
756 return ret;
757 }
758
759 if (reg & ABB5ZES3_REG_RTC_SC_OSC) {
760 dev_err(dev, "clock integrity not guaranteed. Osc. has stopped "
761 "or has been interrupted.\n");
762 dev_err(dev, "change battery (if not already done) and "
763 "then set time to reset osc. failure flag.\n");
764 }
765
766 /*
767 * Check battery low flag at startup: this allows reporting battery
768 * is low at startup when IRQ line is not connected. Note: we record
769 * current status to avoid reenabling this interrupt later in probe
770 * function if battery is low.
771 */
772 ret = regmap_read(regmap, ABB5ZES3_REG_CTRL3, &reg);
773 if (ret < 0) {
774 dev_err(dev, "%s: unable to read battery low flag (%d)\n",
775 __func__, ret);
776 return ret;
777 }
778
779 data->battery_low = reg & ABB5ZES3_REG_CTRL3_BLF;
780 if (data->battery_low) {
781 dev_err(dev, "RTC battery is low; please, consider "
782 "changing it!\n");
783
784 ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, false);
785 if (ret)
786 dev_err(dev, "%s: disabling battery low interrupt "
787 "generation failed (%d)\n", __func__, ret);
788 }
789
790 return ret;
791}
792
793static int abb5zes3_rtc_alarm_irq_enable(struct device *dev,
794 unsigned int enable)
795{
796 struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
797 int ret = 0;
798
799 if (rtc_data->irq) {
800 mutex_lock(&rtc_data->lock);
c8a1d8a5
AE		 801 if (rtc_data->timer_alarm)
802 ret = _abb5zes3_rtc_update_timer(dev, enable);
803 else
804 ret = _abb5zes3_rtc_update_alarm(dev, enable);
0b2f6228
AE		 805 mutex_unlock(&rtc_data->lock);
806 }
807
808 return ret;
809}
810
811static irqreturn_t _abb5zes3_rtc_interrupt(int irq, void *data)
812{
813 struct i2c_client *client = data;
814 struct device *dev = &client->dev;
815 struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
816 struct rtc_device *rtc = rtc_data->rtc;
817 u8 regs[ABB5ZES3_CTRL_SEC_LEN];
818 int ret, handled = IRQ_NONE;
819
820 ret = regmap_bulk_read(rtc_data->regmap, 0, regs,
821 ABB5ZES3_CTRL_SEC_LEN);
822 if (ret) {
823 dev_err(dev, "%s: unable to read control section (%d)!\n",
824 __func__, ret);
825 return handled;
826 }
827
828 /*
829 * Check battery low detection flag and disable battery low interrupt
830 * generation if flag is set (interrupt can only be cleared when
831 * battery is replaced).
832 */
833 if (regs[ABB5ZES3_REG_CTRL3] & ABB5ZES3_REG_CTRL3_BLF) {
834 dev_err(dev, "RTC battery is low; please change it!\n");
835
836 _abb5zes3_rtc_battery_low_irq_enable(rtc_data->regmap, false);
837
838 handled = IRQ_HANDLED;
839 }
840
841 /* Check alarm flag */
842 if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_AF) {
843 dev_dbg(dev, "RTC alarm!\n");
844
845 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
846
847 /* Acknowledge and disable the alarm */
848 _abb5zes3_rtc_clear_alarm(dev);
849 _abb5zes3_rtc_update_alarm(dev, 0);
850
851 handled = IRQ_HANDLED;
852 }
853
c8a1d8a5
AE		 854 /* Check watchdog Timer A flag */
855 if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_WTAF) {
856 dev_dbg(dev, "RTC timer!\n");
857
858 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
859
860 /*
861 * Acknowledge and disable the alarm. Note: WTAF
862 * flag had been cleared when reading CTRL2
863 */
864 _abb5zes3_rtc_update_timer(dev, 0);
865
866 rtc_data->timer_alarm = 0;
867
868 handled = IRQ_HANDLED;
869 }
870
0b2f6228
AE		 871 return handled;
872}
873
874static const struct rtc_class_ops rtc_ops = {
875 .read_time = _abb5zes3_rtc_read_time,
876 .set_time = abb5zes3_rtc_set_time,
877 .read_alarm = abb5zes3_rtc_read_alarm,
878 .set_alarm = abb5zes3_rtc_set_alarm,
879 .alarm_irq_enable = abb5zes3_rtc_alarm_irq_enable,
880};
881
ac2a2726 882static const struct regmap_config abb5zes3_rtc_regmap_config = {
0b2f6228
AE		 883 .reg_bits = 8,
884 .val_bits = 8,
885};
886
887static int abb5zes3_probe(struct i2c_client *client,
888 const struct i2c_device_id *id)
889{
890 struct abb5zes3_rtc_data *data = NULL;
891 struct device *dev = &client->dev;
892 struct regmap *regmap;
893 int ret;
894
895 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
896 I2C_FUNC_SMBUS_BYTE_DATA |
897 I2C_FUNC_SMBUS_I2C_BLOCK)) {
898 ret = -ENODEV;
899 goto err;
900 }
901
902 regmap = devm_regmap_init_i2c(client, &abb5zes3_rtc_regmap_config);
903 if (IS_ERR(regmap)) {
904 ret = PTR_ERR(regmap);
905 dev_err(dev, "%s: regmap allocation failed: %d\n",
906 __func__, ret);
907 goto err;
908 }
909
910 ret = abb5zes3_i2c_validate_chip(regmap);
911 if (ret)
912 goto err;
913
914 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
915 if (!data) {
916 ret = -ENOMEM;
917 goto err;
918 }
919
920 mutex_init(&data->lock);
921 data->regmap = regmap;
922 dev_set_drvdata(dev, data);
923
924 ret = abb5zes3_rtc_check_setup(dev);
925 if (ret)
926 goto err;
927
928 if (client->irq > 0) {
929 ret = devm_request_threaded_irq(dev, client->irq, NULL,
930 _abb5zes3_rtc_interrupt,
931 IRQF_SHARED|IRQF_ONESHOT,
932 DRV_NAME, client);
933 if (!ret) {
934 device_init_wakeup(dev, true);
935 data->irq = client->irq;
936 dev_dbg(dev, "%s: irq %d used by RTC\n", __func__,
937 client->irq);
938 } else {
939 dev_err(dev, "%s: irq %d unavailable (%d)\n",
940 __func__, client->irq, ret);
941 goto err;
942 }
943 }
944
945 data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
946 THIS_MODULE);
947 ret = PTR_ERR_OR_ZERO(data->rtc);
948 if (ret) {
949 dev_err(dev, "%s: unable to register RTC device (%d)\n",
950 __func__, ret);
951 goto err;
952 }
953
0b2f6228
AE		 954 /* Enable battery low detection interrupt if battery not already low */
955 if (!data->battery_low && data->irq) {
956 ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, true);
957 if (ret) {
958 dev_err(dev, "%s: enabling battery low interrupt "
959 "generation failed (%d)\n", __func__, ret);
960 goto err;
961 }
962 }
963
964err:
965 if (ret && data && data->irq)
966 device_init_wakeup(dev, false);
967 return ret;
968}
969
970static int abb5zes3_remove(struct i2c_client *client)
971{
972 struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
973
974 if (rtc_data->irq > 0)
975 device_init_wakeup(&client->dev, false);
976
977 return 0;
978}
979
980#ifdef CONFIG_PM_SLEEP
981static int abb5zes3_rtc_suspend(struct device *dev)
982{
983 struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
984
985 if (device_may_wakeup(dev))
986 return enable_irq_wake(rtc_data->irq);
987
988 return 0;
989}
990
991static int abb5zes3_rtc_resume(struct device *dev)
992{
993 struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
994
995 if (device_may_wakeup(dev))
996 return disable_irq_wake(rtc_data->irq);
997
998 return 0;
999}
1000#endif
1001
1002static SIMPLE_DEV_PM_OPS(abb5zes3_rtc_pm_ops, abb5zes3_rtc_suspend,
1003 abb5zes3_rtc_resume);
1004
1005#ifdef CONFIG_OF
1006static const struct of_device_id abb5zes3_dt_match[] = {
1007 { .compatible = "abracon,abb5zes3" },
1008 { },
1009};
1c4fc295 1010MODULE_DEVICE_TABLE(of, abb5zes3_dt_match);
0b2f6228
AE		 1011#endif
1012
1013static const struct i2c_device_id abb5zes3_id[] = {
1014 { "abb5zes3", 0 },
1015 { }
1016};
1017MODULE_DEVICE_TABLE(i2c, abb5zes3_id);
1018
1019static struct i2c_driver abb5zes3_driver = {
1020 .driver = {
1021 .name = DRV_NAME,
0b2f6228
AE		 1022 .pm = &abb5zes3_rtc_pm_ops,
1023 .of_match_table = of_match_ptr(abb5zes3_dt_match),
1024 },
1025 .probe = abb5zes3_probe,
1026 .remove = abb5zes3_remove,
1027 .id_table = abb5zes3_id,
1028};
1029module_i2c_driver(abb5zes3_driver);
1030
1031MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1032MODULE_DESCRIPTION("Abracon AB-RTCMC-32.768kHz-B5ZE-S3 RTC/Alarm driver");
1033MODULE_LICENSE("GPL");
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