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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Intersil ISL1208 rtc class driver
4 *
5 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
6 */
7
8#include <linux/bcd.h>
9#include <linux/i2c.h>
10#include <linux/module.h>
11#include <linux/of_device.h>
12#include <linux/of_irq.h>
13#include <linux/rtc.h>
14
15/* Register map */
16/* rtc section */
17#define ISL1208_REG_SC 0x00
18#define ISL1208_REG_MN 0x01
19#define ISL1208_REG_HR 0x02
20#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
21#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
22#define ISL1208_REG_DT 0x03
23#define ISL1208_REG_MO 0x04
24#define ISL1208_REG_YR 0x05
25#define ISL1208_REG_DW 0x06
26#define ISL1208_RTC_SECTION_LEN 7
27
28/* control/status section */
29#define ISL1208_REG_SR 0x07
30#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
31#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
32#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
33#define ISL1208_REG_SR_EVT (1<<3) /* event */
34#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
35#define ISL1208_REG_SR_BAT (1<<1) /* battery */
36#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
37#define ISL1208_REG_INT 0x08
38#define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
39#define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
40#define ISL1219_REG_EV 0x09
41#define ISL1219_REG_EV_EVEN (1<<4) /* event detection enable */
42#define ISL1219_REG_EV_EVIENB (1<<7) /* event in pull-up disable */
43#define ISL1208_REG_ATR 0x0a
44#define ISL1208_REG_DTR 0x0b
45
46/* alarm section */
47#define ISL1208_REG_SCA 0x0c
48#define ISL1208_REG_MNA 0x0d
49#define ISL1208_REG_HRA 0x0e
50#define ISL1208_REG_DTA 0x0f
51#define ISL1208_REG_MOA 0x10
52#define ISL1208_REG_DWA 0x11
53#define ISL1208_ALARM_SECTION_LEN 6
54
55/* user section */
56#define ISL1208_REG_USR1 0x12
57#define ISL1208_REG_USR2 0x13
58#define ISL1208_USR_SECTION_LEN 2
59
60/* event section */
61#define ISL1219_REG_SCT 0x14
62#define ISL1219_REG_MNT 0x15
63#define ISL1219_REG_HRT 0x16
64#define ISL1219_REG_DTT 0x17
65#define ISL1219_REG_MOT 0x18
66#define ISL1219_REG_YRT 0x19
67#define ISL1219_EVT_SECTION_LEN 6
68
69static struct i2c_driver isl1208_driver;
70
71/* ISL1208 various variants */
72enum isl1208_id {
73 TYPE_ISL1208 = 0,
74 TYPE_ISL1209,
75 TYPE_ISL1218,
76 TYPE_ISL1219,
77 ISL_LAST_ID
78};
79
80/* Chip capabilities table */
81static const struct isl1208_config {
82 const char name[8];
83 unsigned int nvmem_length;
84 unsigned has_tamper:1;
85 unsigned has_timestamp:1;
86} isl1208_configs[] = {
87 [TYPE_ISL1208] = { "isl1208", 2, false, false },
88 [TYPE_ISL1209] = { "isl1209", 2, true, false },
89 [TYPE_ISL1218] = { "isl1218", 8, false, false },
90 [TYPE_ISL1219] = { "isl1219", 2, true, true },
91};
92
93static const struct i2c_device_id isl1208_id[] = {
94 { "isl1208", TYPE_ISL1208 },
95 { "isl1209", TYPE_ISL1209 },
96 { "isl1218", TYPE_ISL1218 },
97 { "isl1219", TYPE_ISL1219 },
98 { }
99};
100MODULE_DEVICE_TABLE(i2c, isl1208_id);
101
102static const struct of_device_id isl1208_of_match[] = {
103 { .compatible = "isil,isl1208", .data = &isl1208_configs[TYPE_ISL1208] },
104 { .compatible = "isil,isl1209", .data = &isl1208_configs[TYPE_ISL1209] },
105 { .compatible = "isil,isl1218", .data = &isl1208_configs[TYPE_ISL1218] },
106 { .compatible = "isil,isl1219", .data = &isl1208_configs[TYPE_ISL1219] },
107 { }
108};
109MODULE_DEVICE_TABLE(of, isl1208_of_match);
110
111/* Device state */
112struct isl1208_state {
113 struct nvmem_config nvmem_config;
114 struct rtc_device *rtc;
115 const struct isl1208_config *config;
116};
117
118/* block read */
119static int
120isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
121 unsigned len)
122{
123 int ret;
124
125 WARN_ON(reg > ISL1219_REG_YRT);
126 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
127
128 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
129 return (ret < 0) ? ret : 0;
130}
131
132/* block write */
133static int
134isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
135 unsigned len)
136{
137 int ret;
138
139 WARN_ON(reg > ISL1219_REG_YRT);
140 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
141
142 ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
143 return (ret < 0) ? ret : 0;
144}
145
146/* simple check to see whether we have a isl1208 */
147static int
148isl1208_i2c_validate_client(struct i2c_client *client)
149{
150 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
151 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
152 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
153 };
154 int i;
155 int ret;
156
157 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
158 if (ret < 0)
159 return ret;
160
161 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
162 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
163 return -ENODEV;
164 }
165
166 return 0;
167}
168
169static int
170isl1208_i2c_get_sr(struct i2c_client *client)
171{
172 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
173}
174
175static int
176isl1208_i2c_get_atr(struct i2c_client *client)
177{
178 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
179 if (atr < 0)
180 return atr;
181
182 /* The 6bit value in the ATR register controls the load
183 * capacitance C_load * in steps of 0.25pF
184 *
185 * bit (1<<5) of the ATR register is inverted
186 *
187 * C_load(ATR=0x20) = 4.50pF
188 * C_load(ATR=0x00) = 12.50pF
189 * C_load(ATR=0x1f) = 20.25pF
190 *
191 */
192
193 atr &= 0x3f; /* mask out lsb */
194 atr ^= 1 << 5; /* invert 6th bit */
195 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
196
197 return atr;
198}
199
200/* returns adjustment value + 100 */
201static int
202isl1208_i2c_get_dtr(struct i2c_client *client)
203{
204 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
205 if (dtr < 0)
206 return -EIO;
207
208 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
209 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
210
211 return dtr + 100;
212}
213
214static int
215isl1208_i2c_get_usr(struct i2c_client *client)
216{
217 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
218 int ret;
219
220 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
221 ISL1208_USR_SECTION_LEN);
222 if (ret < 0)
223 return ret;
224
225 return (buf[1] << 8) | buf[0];
226}
227
228static int
229isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
230{
231 u8 buf[ISL1208_USR_SECTION_LEN];
232
233 buf[0] = usr & 0xff;
234 buf[1] = (usr >> 8) & 0xff;
235
236 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
237 ISL1208_USR_SECTION_LEN);
238}
239
240static int
241isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
242{
243 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
244
245 if (icr < 0) {
246 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
247 return icr;
248 }
249
250 if (enable)
251 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
252 else
253 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
254
255 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
256 if (icr < 0) {
257 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
258 return icr;
259 }
260
261 return 0;
262}
263
264static int
265isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
266{
267 struct i2c_client *const client = to_i2c_client(dev);
268 int sr, dtr, atr, usr;
269
270 sr = isl1208_i2c_get_sr(client);
271 if (sr < 0) {
272 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
273 return sr;
274 }
275
276 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
277 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
278 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
279 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
280 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
281 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
282 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
283
284 seq_printf(seq, "batt_status\t: %s\n",
285 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
286
287 dtr = isl1208_i2c_get_dtr(client);
288 if (dtr >= 0)
289 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100);
290
291 atr = isl1208_i2c_get_atr(client);
292 if (atr >= 0)
293 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
294 atr >> 2, (atr & 0x3) * 25);
295
296 usr = isl1208_i2c_get_usr(client);
297 if (usr >= 0)
298 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
299
300 return 0;
301}
302
303static int
304isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
305{
306 int sr;
307 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
308
309 sr = isl1208_i2c_get_sr(client);
310 if (sr < 0) {
311 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
312 return -EIO;
313 }
314
315 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
316 if (sr < 0) {
317 dev_err(&client->dev, "%s: reading RTC section failed\n",
318 __func__);
319 return sr;
320 }
321
322 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
323 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
324
325 /* HR field has a more complex interpretation */
326 {
327 const u8 _hr = regs[ISL1208_REG_HR];
328 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
329 tm->tm_hour = bcd2bin(_hr & 0x3f);
330 else {
331 /* 12h format */
332 tm->tm_hour = bcd2bin(_hr & 0x1f);
333 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
334 tm->tm_hour += 12;
335 }
336 }
337
338 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
339 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
340 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
341 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
342
343 return 0;
344}
345
346static int
347isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
348{
349 struct rtc_time *const tm = &alarm->time;
350 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
351 int icr, yr, sr = isl1208_i2c_get_sr(client);
352
353 if (sr < 0) {
354 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
355 return sr;
356 }
357
358 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
359 ISL1208_ALARM_SECTION_LEN);
360 if (sr < 0) {
361 dev_err(&client->dev, "%s: reading alarm section failed\n",
362 __func__);
363 return sr;
364 }
365
366 /* MSB of each alarm register is an enable bit */
367 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
368 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
369 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
370 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
371 tm->tm_mon =
372 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
373 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
374
375 /* The alarm doesn't store the year so get it from the rtc section */
376 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
377 if (yr < 0) {
378 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
379 return yr;
380 }
381 tm->tm_year = bcd2bin(yr) + 100;
382
383 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
384 if (icr < 0) {
385 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
386 return icr;
387 }
388 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
389
390 return 0;
391}
392
393static int
394isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
395{
396 struct rtc_time *alarm_tm = &alarm->time;
397 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
398 const int offs = ISL1208_REG_SCA;
399 struct rtc_time rtc_tm;
400 int err, enable;
401
402 err = isl1208_i2c_read_time(client, &rtc_tm);
403 if (err)
404 return err;
405
406 /* If the alarm time is before the current time disable the alarm */
407 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
408 enable = 0x00;
409 else
410 enable = 0x80;
411
412 /* Program the alarm and enable it for each setting */
413 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
414 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
415 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
416 ISL1208_REG_HR_MIL | enable;
417
418 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
419 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
420 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
421
422 /* write ALARM registers */
423 err = isl1208_i2c_set_regs(client, offs, regs,
424 ISL1208_ALARM_SECTION_LEN);
425 if (err < 0) {
426 dev_err(&client->dev, "%s: writing ALARM section failed\n",
427 __func__);
428 return err;
429 }
430
431 err = isl1208_rtc_toggle_alarm(client, enable);
432 if (err)
433 return err;
434
435 return 0;
436}
437
438static int
439isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
440{
441 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
442}
443
444static int
445isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
446{
447 int sr;
448 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
449
450 /* The clock has an 8 bit wide bcd-coded register (they never learn)
451 * for the year. tm_year is an offset from 1900 and we are interested
452 * in the 2000-2099 range, so any value less than 100 is invalid.
453 */
454 if (tm->tm_year < 100)
455 return -EINVAL;
456
457 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
458 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
459 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
460
461 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
462 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
463 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
464
465 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
466
467 sr = isl1208_i2c_get_sr(client);
468 if (sr < 0) {
469 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
470 return sr;
471 }
472
473 /* set WRTC */
474 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
475 sr | ISL1208_REG_SR_WRTC);
476 if (sr < 0) {
477 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
478 return sr;
479 }
480
481 /* write RTC registers */
482 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
483 if (sr < 0) {
484 dev_err(&client->dev, "%s: writing RTC section failed\n",
485 __func__);
486 return sr;
487 }
488
489 /* clear WRTC again */
490 sr = isl1208_i2c_get_sr(client);
491 if (sr < 0) {
492 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
493 return sr;
494 }
495 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
496 sr & ~ISL1208_REG_SR_WRTC);
497 if (sr < 0) {
498 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
499 return sr;
500 }
501
502 return 0;
503}
504
505
506static int
507isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
508{
509 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
510}
511
512static int
513isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
514{
515 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
516}
517
518static int
519isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
520{
521 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
522}
523
524static ssize_t timestamp0_store(struct device *dev,
525 struct device_attribute *attr,
526 const char *buf, size_t count)
527{
528 struct i2c_client *client = to_i2c_client(dev->parent);
529 int sr;
530
531 sr = isl1208_i2c_get_sr(client);
532 if (sr < 0) {
533 dev_err(dev, "%s: reading SR failed\n", __func__);
534 return sr;
535 }
536
537 sr &= ~ISL1208_REG_SR_EVT;
538
539 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
540 if (sr < 0)
541 dev_err(dev, "%s: writing SR failed\n",
542 __func__);
543
544 return count;
545};
546
547static ssize_t timestamp0_show(struct device *dev,
548 struct device_attribute *attr, char *buf)
549{
550 struct i2c_client *client = to_i2c_client(dev->parent);
551 u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
552 struct rtc_time tm;
553 int sr;
554
555 sr = isl1208_i2c_get_sr(client);
556 if (sr < 0) {
557 dev_err(dev, "%s: reading SR failed\n", __func__);
558 return sr;
559 }
560
561 if (!(sr & ISL1208_REG_SR_EVT))
562 return 0;
563
564 sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
565 ISL1219_EVT_SECTION_LEN);
566 if (sr < 0) {
567 dev_err(dev, "%s: reading event section failed\n",
568 __func__);
569 return 0;
570 }
571
572 /* MSB of each alarm register is an enable bit */
573 tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
574 tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
575 tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
576 tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
577 tm.tm_mon =
578 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
579 tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
580
581 sr = rtc_valid_tm(&tm);
582 if (sr)
583 return sr;
584
585 return sprintf(buf, "%llu\n",
586 (unsigned long long)rtc_tm_to_time64(&tm));
587};
588
589static DEVICE_ATTR_RW(timestamp0);
590
591static irqreturn_t
592isl1208_rtc_interrupt(int irq, void *data)
593{
594 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
595 struct i2c_client *client = data;
596 struct isl1208_state *isl1208 = i2c_get_clientdata(client);
597 int handled = 0, sr, err;
598
599 /*
600 * I2C reads get NAK'ed if we read straight away after an interrupt?
601 * Using a mdelay/msleep didn't seem to help either, so we work around
602 * this by continually trying to read the register for a short time.
603 */
604 while (1) {
605 sr = isl1208_i2c_get_sr(client);
606 if (sr >= 0)
607 break;
608
609 if (time_after(jiffies, timeout)) {
610 dev_err(&client->dev, "%s: reading SR failed\n",
611 __func__);
612 return sr;
613 }
614 }
615
616 if (sr & ISL1208_REG_SR_ALM) {
617 dev_dbg(&client->dev, "alarm!\n");
618
619 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
620
621 /* Clear the alarm */
622 sr &= ~ISL1208_REG_SR_ALM;
623 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
624 if (sr < 0)
625 dev_err(&client->dev, "%s: writing SR failed\n",
626 __func__);
627 else
628 handled = 1;
629
630 /* Disable the alarm */
631 err = isl1208_rtc_toggle_alarm(client, 0);
632 if (err)
633 return err;
634 }
635
636 if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
637 dev_warn(&client->dev, "event detected");
638 handled = 1;
639 if (isl1208->config->has_timestamp)
640 sysfs_notify(&isl1208->rtc->dev.kobj, NULL,
641 dev_attr_timestamp0.attr.name);
642 }
643
644 return handled ? IRQ_HANDLED : IRQ_NONE;
645}
646
647static const struct rtc_class_ops isl1208_rtc_ops = {
648 .proc = isl1208_rtc_proc,
649 .read_time = isl1208_rtc_read_time,
650 .set_time = isl1208_rtc_set_time,
651 .read_alarm = isl1208_rtc_read_alarm,
652 .set_alarm = isl1208_rtc_set_alarm,
653};
654
655/* sysfs interface */
656
657static ssize_t
658isl1208_sysfs_show_atrim(struct device *dev,
659 struct device_attribute *attr, char *buf)
660{
661 int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent));
662 if (atr < 0)
663 return atr;
664
665 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
666}
667
668static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
669
670static ssize_t
671isl1208_sysfs_show_dtrim(struct device *dev,
672 struct device_attribute *attr, char *buf)
673{
674 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent));
675 if (dtr < 0)
676 return dtr;
677
678 return sprintf(buf, "%d ppm\n", dtr - 100);
679}
680
681static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
682
683static ssize_t
684isl1208_sysfs_show_usr(struct device *dev,
685 struct device_attribute *attr, char *buf)
686{
687 int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent));
688 if (usr < 0)
689 return usr;
690
691 return sprintf(buf, "0x%.4x\n", usr);
692}
693
694static ssize_t
695isl1208_sysfs_store_usr(struct device *dev,
696 struct device_attribute *attr,
697 const char *buf, size_t count)
698{
699 int usr = -1;
700
701 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
702 if (sscanf(buf, "%x", &usr) != 1)
703 return -EINVAL;
704 } else {
705 if (sscanf(buf, "%d", &usr) != 1)
706 return -EINVAL;
707 }
708
709 if (usr < 0 || usr > 0xffff)
710 return -EINVAL;
711
712 if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr))
713 return -EIO;
714
715 return count;
716}
717
718static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
719 isl1208_sysfs_store_usr);
720
721static struct attribute *isl1208_rtc_attrs[] = {
722 &dev_attr_atrim.attr,
723 &dev_attr_dtrim.attr,
724 &dev_attr_usr.attr,
725 NULL
726};
727
728static const struct attribute_group isl1208_rtc_sysfs_files = {
729 .attrs = isl1208_rtc_attrs,
730};
731
732static struct attribute *isl1219_rtc_attrs[] = {
733 &dev_attr_timestamp0.attr,
734 NULL
735};
736
737static const struct attribute_group isl1219_rtc_sysfs_files = {
738 .attrs = isl1219_rtc_attrs,
739};
740
741static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
742 size_t count)
743{
744 struct isl1208_state *isl1208 = priv;
745 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
746 int ret;
747
748 /* nvmem sanitizes offset/count for us, but count==0 is possible */
749 if (!count)
750 return count;
751 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf,
752 count);
753 return ret == 0 ? count : ret;
754}
755
756static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
757 size_t count)
758{
759 struct isl1208_state *isl1208 = priv;
760 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
761 int ret;
762
763 /* nvmem sanitizes off/count for us, but count==0 is possible */
764 if (!count)
765 return count;
766 ret = isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf,
767 count);
768
769 return ret == 0 ? count : ret;
770}
771
772static const struct nvmem_config isl1208_nvmem_config = {
773 .name = "isl1208_nvram",
774 .word_size = 1,
775 .stride = 1,
776 /* .size from chip specific config */
777 .reg_read = isl1208_nvmem_read,
778 .reg_write = isl1208_nvmem_write,
779};
780
781static int isl1208_setup_irq(struct i2c_client *client, int irq)
782{
783 int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
784 isl1208_rtc_interrupt,
785 IRQF_SHARED | IRQF_ONESHOT,
786 isl1208_driver.driver.name,
787 client);
788 if (!rc) {
789 device_init_wakeup(&client->dev, 1);
790 enable_irq_wake(irq);
791 } else {
792 dev_err(&client->dev,
793 "Unable to request irq %d, no alarm support\n",
794 irq);
795 }
796 return rc;
797}
798
799static int
800isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
801{
802 int rc = 0;
803 struct isl1208_state *isl1208;
804 int evdet_irq = -1;
805
806 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
807 return -ENODEV;
808
809 if (isl1208_i2c_validate_client(client) < 0)
810 return -ENODEV;
811
812 /* Allocate driver state, point i2c client data to it */
813 isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL);
814 if (!isl1208)
815 return -ENOMEM;
816 i2c_set_clientdata(client, isl1208);
817
818 /* Determine which chip we have */
819 if (client->dev.of_node) {
820 isl1208->config = of_device_get_match_data(&client->dev);
821 if (!isl1208->config)
822 return -ENODEV;
823 } else {
824 if (id->driver_data >= ISL_LAST_ID)
825 return -ENODEV;
826 isl1208->config = &isl1208_configs[id->driver_data];
827 }
828
829 isl1208->rtc = devm_rtc_allocate_device(&client->dev);
830 if (IS_ERR(isl1208->rtc))
831 return PTR_ERR(isl1208->rtc);
832
833 isl1208->rtc->ops = &isl1208_rtc_ops;
834
835 /* Setup nvmem configuration in driver state struct */
836 isl1208->nvmem_config = isl1208_nvmem_config;
837 isl1208->nvmem_config.size = isl1208->config->nvmem_length;
838 isl1208->nvmem_config.priv = isl1208;
839
840 rc = isl1208_i2c_get_sr(client);
841 if (rc < 0) {
842 dev_err(&client->dev, "reading status failed\n");
843 return rc;
844 }
845
846 if (rc & ISL1208_REG_SR_RTCF)
847 dev_warn(&client->dev, "rtc power failure detected, "
848 "please set clock.\n");
849
850 if (isl1208->config->has_tamper) {
851 struct device_node *np = client->dev.of_node;
852 u32 evienb;
853
854 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
855 if (rc < 0) {
856 dev_err(&client->dev, "failed to read EV reg\n");
857 return rc;
858 }
859 rc |= ISL1219_REG_EV_EVEN;
860 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
861 if (evienb)
862 rc |= ISL1219_REG_EV_EVIENB;
863 else
864 rc &= ~ISL1219_REG_EV_EVIENB;
865 }
866 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
867 if (rc < 0) {
868 dev_err(&client->dev, "could not enable tamper detection\n");
869 return rc;
870 }
871 evdet_irq = of_irq_get_byname(np, "evdet");
872 }
873 if (isl1208->config->has_timestamp) {
874 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files);
875 if (rc)
876 return rc;
877 }
878
879 rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files);
880 if (rc)
881 return rc;
882
883 if (client->irq > 0)
884 rc = isl1208_setup_irq(client, client->irq);
885 if (rc)
886 return rc;
887
888 if (evdet_irq > 0 && evdet_irq != client->irq)
889 rc = isl1208_setup_irq(client, evdet_irq);
890 if (rc)
891 return rc;
892
893 rc = rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config);
894 if (rc)
895 return rc;
896
897 return rtc_register_device(isl1208->rtc);
898}
899
900static struct i2c_driver isl1208_driver = {
901 .driver = {
902 .name = "rtc-isl1208",
903 .of_match_table = of_match_ptr(isl1208_of_match),
904 },
905 .probe = isl1208_probe,
906 .id_table = isl1208_id,
907};
908
909module_i2c_driver(isl1208_driver);
910
911MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
912MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
913MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Intersil ISL1208 rtc class driver
4 *
5 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
6 */
7
8#include <linux/bcd.h>
9#include <linux/clk.h>
10#include <linux/delay.h>
11#include <linux/i2c.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_irq.h>
15#include <linux/rtc.h>
16
17/* Register map */
18/* rtc section */
19#define ISL1208_REG_SC 0x00
20#define ISL1208_REG_MN 0x01
21#define ISL1208_REG_HR 0x02
22#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
23#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
24#define ISL1208_REG_DT 0x03
25#define ISL1208_REG_MO 0x04
26#define ISL1208_REG_YR 0x05
27#define ISL1208_REG_DW 0x06
28#define ISL1208_RTC_SECTION_LEN 7
29
30/* control/status section */
31#define ISL1208_REG_SR 0x07
32#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
33#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
34#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
35#define ISL1208_REG_SR_EVT (1<<3) /* event */
36#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
37#define ISL1208_REG_SR_BAT (1<<1) /* battery */
38#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
39#define ISL1208_REG_INT 0x08
40#define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
41#define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
42#define ISL1219_REG_EV 0x09
43#define ISL1219_REG_EV_EVEN (1<<4) /* event detection enable */
44#define ISL1219_REG_EV_EVIENB (1<<7) /* event in pull-up disable */
45#define ISL1208_REG_ATR 0x0a
46#define ISL1208_REG_DTR 0x0b
47
48/* alarm section */
49#define ISL1208_REG_SCA 0x0c
50#define ISL1208_REG_MNA 0x0d
51#define ISL1208_REG_HRA 0x0e
52#define ISL1208_REG_DTA 0x0f
53#define ISL1208_REG_MOA 0x10
54#define ISL1208_REG_DWA 0x11
55#define ISL1208_ALARM_SECTION_LEN 6
56
57/* user section */
58#define ISL1208_REG_USR1 0x12
59#define ISL1208_REG_USR2 0x13
60#define ISL1208_USR_SECTION_LEN 2
61
62/* event section */
63#define ISL1219_REG_SCT 0x14
64#define ISL1219_REG_MNT 0x15
65#define ISL1219_REG_HRT 0x16
66#define ISL1219_REG_DTT 0x17
67#define ISL1219_REG_MOT 0x18
68#define ISL1219_REG_YRT 0x19
69#define ISL1219_EVT_SECTION_LEN 6
70
71static struct i2c_driver isl1208_driver;
72
73/* Chip capabilities table */
74struct isl1208_config {
75 unsigned int nvmem_length;
76 unsigned has_tamper:1;
77 unsigned has_timestamp:1;
78 unsigned has_inverted_osc_bit:1;
79};
80
81static const struct isl1208_config config_isl1208 = {
82 .nvmem_length = 2,
83 .has_tamper = false,
84 .has_timestamp = false
85};
86
87static const struct isl1208_config config_isl1209 = {
88 .nvmem_length = 2,
89 .has_tamper = true,
90 .has_timestamp = false
91};
92
93static const struct isl1208_config config_isl1218 = {
94 .nvmem_length = 8,
95 .has_tamper = false,
96 .has_timestamp = false
97};
98
99static const struct isl1208_config config_isl1219 = {
100 .nvmem_length = 2,
101 .has_tamper = true,
102 .has_timestamp = true
103};
104
105static const struct isl1208_config config_raa215300_a0 = {
106 .nvmem_length = 2,
107 .has_tamper = false,
108 .has_timestamp = false,
109 .has_inverted_osc_bit = true
110};
111
112static const struct i2c_device_id isl1208_id[] = {
113 { "isl1208", .driver_data = (kernel_ulong_t)&config_isl1208 },
114 { "isl1209", .driver_data = (kernel_ulong_t)&config_isl1209 },
115 { "isl1218", .driver_data = (kernel_ulong_t)&config_isl1218 },
116 { "isl1219", .driver_data = (kernel_ulong_t)&config_isl1219 },
117 { "raa215300_a0", .driver_data = (kernel_ulong_t)&config_raa215300_a0 },
118 { }
119};
120MODULE_DEVICE_TABLE(i2c, isl1208_id);
121
122static const __maybe_unused struct of_device_id isl1208_of_match[] = {
123 { .compatible = "isil,isl1208", .data = &config_isl1208 },
124 { .compatible = "isil,isl1209", .data = &config_isl1209 },
125 { .compatible = "isil,isl1218", .data = &config_isl1218 },
126 { .compatible = "isil,isl1219", .data = &config_isl1219 },
127 { }
128};
129MODULE_DEVICE_TABLE(of, isl1208_of_match);
130
131/* Device state */
132struct isl1208_state {
133 struct nvmem_config nvmem_config;
134 struct rtc_device *rtc;
135 const struct isl1208_config *config;
136};
137
138/* block read */
139static int
140isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
141 unsigned len)
142{
143 int ret;
144
145 WARN_ON(reg > ISL1219_REG_YRT);
146 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
147
148 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
149 return (ret < 0) ? ret : 0;
150}
151
152/* block write */
153static int
154isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
155 unsigned len)
156{
157 int ret;
158
159 WARN_ON(reg > ISL1219_REG_YRT);
160 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
161
162 ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
163 return (ret < 0) ? ret : 0;
164}
165
166/* simple check to see whether we have a isl1208 */
167static int
168isl1208_i2c_validate_client(struct i2c_client *client)
169{
170 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
171 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
172 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
173 };
174 int i;
175 int ret;
176
177 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
178 if (ret < 0)
179 return ret;
180
181 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
182 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
183 return -ENODEV;
184 }
185
186 return 0;
187}
188
189static int isl1208_set_xtoscb(struct i2c_client *client, int sr, int xtosb_val)
190{
191 /* Do nothing if bit is already set to desired value */
192 if (!!(sr & ISL1208_REG_SR_XTOSCB) == xtosb_val)
193 return 0;
194
195 if (xtosb_val)
196 sr |= ISL1208_REG_SR_XTOSCB;
197 else
198 sr &= ~ISL1208_REG_SR_XTOSCB;
199
200 return i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
201}
202
203static int
204isl1208_i2c_get_sr(struct i2c_client *client)
205{
206 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
207}
208
209static int
210isl1208_i2c_get_atr(struct i2c_client *client)
211{
212 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
213 if (atr < 0)
214 return atr;
215
216 /* The 6bit value in the ATR register controls the load
217 * capacitance C_load * in steps of 0.25pF
218 *
219 * bit (1<<5) of the ATR register is inverted
220 *
221 * C_load(ATR=0x20) = 4.50pF
222 * C_load(ATR=0x00) = 12.50pF
223 * C_load(ATR=0x1f) = 20.25pF
224 *
225 */
226
227 atr &= 0x3f; /* mask out lsb */
228 atr ^= 1 << 5; /* invert 6th bit */
229 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
230
231 return atr;
232}
233
234/* returns adjustment value + 100 */
235static int
236isl1208_i2c_get_dtr(struct i2c_client *client)
237{
238 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
239 if (dtr < 0)
240 return -EIO;
241
242 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
243 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
244
245 return dtr + 100;
246}
247
248static int
249isl1208_i2c_get_usr(struct i2c_client *client)
250{
251 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
252 int ret;
253
254 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
255 ISL1208_USR_SECTION_LEN);
256 if (ret < 0)
257 return ret;
258
259 return (buf[1] << 8) | buf[0];
260}
261
262static int
263isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
264{
265 u8 buf[ISL1208_USR_SECTION_LEN];
266
267 buf[0] = usr & 0xff;
268 buf[1] = (usr >> 8) & 0xff;
269
270 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
271 ISL1208_USR_SECTION_LEN);
272}
273
274static int
275isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
276{
277 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
278
279 if (icr < 0) {
280 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
281 return icr;
282 }
283
284 if (enable)
285 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
286 else
287 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
288
289 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
290 if (icr < 0) {
291 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
292 return icr;
293 }
294
295 return 0;
296}
297
298static int
299isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
300{
301 struct i2c_client *const client = to_i2c_client(dev);
302 int sr, dtr, atr, usr;
303
304 sr = isl1208_i2c_get_sr(client);
305 if (sr < 0) {
306 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
307 return sr;
308 }
309
310 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
311 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
312 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
313 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
314 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
315 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
316 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
317
318 seq_printf(seq, "batt_status\t: %s\n",
319 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
320
321 dtr = isl1208_i2c_get_dtr(client);
322 if (dtr >= 0)
323 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100);
324
325 atr = isl1208_i2c_get_atr(client);
326 if (atr >= 0)
327 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
328 atr >> 2, (atr & 0x3) * 25);
329
330 usr = isl1208_i2c_get_usr(client);
331 if (usr >= 0)
332 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
333
334 return 0;
335}
336
337static int
338isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
339{
340 int sr;
341 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
342
343 sr = isl1208_i2c_get_sr(client);
344 if (sr < 0) {
345 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
346 return -EIO;
347 }
348
349 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
350 if (sr < 0) {
351 dev_err(&client->dev, "%s: reading RTC section failed\n",
352 __func__);
353 return sr;
354 }
355
356 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
357 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
358
359 /* HR field has a more complex interpretation */
360 {
361 const u8 _hr = regs[ISL1208_REG_HR];
362 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
363 tm->tm_hour = bcd2bin(_hr & 0x3f);
364 else {
365 /* 12h format */
366 tm->tm_hour = bcd2bin(_hr & 0x1f);
367 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
368 tm->tm_hour += 12;
369 }
370 }
371
372 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
373 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
374 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
375 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
376
377 return 0;
378}
379
380static int
381isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
382{
383 struct rtc_time *const tm = &alarm->time;
384 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
385 int icr, yr, sr = isl1208_i2c_get_sr(client);
386
387 if (sr < 0) {
388 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
389 return sr;
390 }
391
392 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
393 ISL1208_ALARM_SECTION_LEN);
394 if (sr < 0) {
395 dev_err(&client->dev, "%s: reading alarm section failed\n",
396 __func__);
397 return sr;
398 }
399
400 /* MSB of each alarm register is an enable bit */
401 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
402 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
403 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
404 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
405 tm->tm_mon =
406 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
407 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
408
409 /* The alarm doesn't store the year so get it from the rtc section */
410 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
411 if (yr < 0) {
412 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
413 return yr;
414 }
415 tm->tm_year = bcd2bin(yr) + 100;
416
417 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
418 if (icr < 0) {
419 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
420 return icr;
421 }
422 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
423
424 return 0;
425}
426
427static int
428isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
429{
430 struct rtc_time *alarm_tm = &alarm->time;
431 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
432 const int offs = ISL1208_REG_SCA;
433 struct rtc_time rtc_tm;
434 int err, enable;
435
436 err = isl1208_i2c_read_time(client, &rtc_tm);
437 if (err)
438 return err;
439
440 /* If the alarm time is before the current time disable the alarm */
441 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
442 enable = 0x00;
443 else
444 enable = 0x80;
445
446 /* Program the alarm and enable it for each setting */
447 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
448 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
449 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
450 ISL1208_REG_HR_MIL | enable;
451
452 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
453 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
454 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
455
456 /* write ALARM registers */
457 err = isl1208_i2c_set_regs(client, offs, regs,
458 ISL1208_ALARM_SECTION_LEN);
459 if (err < 0) {
460 dev_err(&client->dev, "%s: writing ALARM section failed\n",
461 __func__);
462 return err;
463 }
464
465 err = isl1208_rtc_toggle_alarm(client, enable);
466 if (err)
467 return err;
468
469 return 0;
470}
471
472static int
473isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
474{
475 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
476}
477
478static int
479isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
480{
481 int sr;
482 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
483
484 /* The clock has an 8 bit wide bcd-coded register (they never learn)
485 * for the year. tm_year is an offset from 1900 and we are interested
486 * in the 2000-2099 range, so any value less than 100 is invalid.
487 */
488 if (tm->tm_year < 100)
489 return -EINVAL;
490
491 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
492 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
493 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
494
495 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
496 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
497 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
498
499 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
500
501 sr = isl1208_i2c_get_sr(client);
502 if (sr < 0) {
503 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
504 return sr;
505 }
506
507 /* set WRTC */
508 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
509 sr | ISL1208_REG_SR_WRTC);
510 if (sr < 0) {
511 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
512 return sr;
513 }
514
515 /* write RTC registers */
516 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
517 if (sr < 0) {
518 dev_err(&client->dev, "%s: writing RTC section failed\n",
519 __func__);
520 return sr;
521 }
522
523 /* clear WRTC again */
524 sr = isl1208_i2c_get_sr(client);
525 if (sr < 0) {
526 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
527 return sr;
528 }
529 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
530 sr & ~ISL1208_REG_SR_WRTC);
531 if (sr < 0) {
532 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
533 return sr;
534 }
535
536 return 0;
537}
538
539static int
540isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
541{
542 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
543}
544
545static int
546isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
547{
548 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
549}
550
551static int
552isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
553{
554 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
555}
556
557static ssize_t timestamp0_store(struct device *dev,
558 struct device_attribute *attr,
559 const char *buf, size_t count)
560{
561 struct i2c_client *client = to_i2c_client(dev->parent);
562 int sr;
563
564 sr = isl1208_i2c_get_sr(client);
565 if (sr < 0) {
566 dev_err(dev, "%s: reading SR failed\n", __func__);
567 return sr;
568 }
569
570 sr &= ~ISL1208_REG_SR_EVT;
571
572 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
573 if (sr < 0)
574 dev_err(dev, "%s: writing SR failed\n",
575 __func__);
576
577 return count;
578};
579
580static ssize_t timestamp0_show(struct device *dev,
581 struct device_attribute *attr, char *buf)
582{
583 struct i2c_client *client = to_i2c_client(dev->parent);
584 u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
585 struct rtc_time tm;
586 int sr;
587
588 sr = isl1208_i2c_get_sr(client);
589 if (sr < 0) {
590 dev_err(dev, "%s: reading SR failed\n", __func__);
591 return sr;
592 }
593
594 if (!(sr & ISL1208_REG_SR_EVT))
595 return 0;
596
597 sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
598 ISL1219_EVT_SECTION_LEN);
599 if (sr < 0) {
600 dev_err(dev, "%s: reading event section failed\n",
601 __func__);
602 return 0;
603 }
604
605 /* MSB of each alarm register is an enable bit */
606 tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
607 tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
608 tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
609 tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
610 tm.tm_mon =
611 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
612 tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
613
614 sr = rtc_valid_tm(&tm);
615 if (sr)
616 return sr;
617
618 return sprintf(buf, "%llu\n",
619 (unsigned long long)rtc_tm_to_time64(&tm));
620};
621
622static DEVICE_ATTR_RW(timestamp0);
623
624static irqreturn_t
625isl1208_rtc_interrupt(int irq, void *data)
626{
627 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
628 struct i2c_client *client = data;
629 struct isl1208_state *isl1208 = i2c_get_clientdata(client);
630 int handled = 0, sr, err;
631
632 if (!isl1208->config->has_tamper) {
633 /*
634 * The INT# output is pulled low 250ms after the alarm is
635 * triggered. After the INT# output is pulled low, it is low for
636 * at least 250ms, even if the correct action is taken to clear
637 * it. It is impossible to clear ALM if it is still active. The
638 * host must wait for the RTC to progress past the alarm time
639 * plus the 250ms delay before clearing ALM.
640 */
641 msleep(250);
642 }
643
644 /*
645 * I2C reads get NAK'ed if we read straight away after an interrupt?
646 * Using a mdelay/msleep didn't seem to help either, so we work around
647 * this by continually trying to read the register for a short time.
648 */
649 while (1) {
650 sr = isl1208_i2c_get_sr(client);
651 if (sr >= 0)
652 break;
653
654 if (time_after(jiffies, timeout)) {
655 dev_err(&client->dev, "%s: reading SR failed\n",
656 __func__);
657 return sr;
658 }
659 }
660
661 if (sr & ISL1208_REG_SR_ALM) {
662 dev_dbg(&client->dev, "alarm!\n");
663
664 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
665
666 /* Disable the alarm */
667 err = isl1208_rtc_toggle_alarm(client, 0);
668 if (err)
669 return err;
670
671 fsleep(275);
672
673 /* Clear the alarm */
674 sr &= ~ISL1208_REG_SR_ALM;
675 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
676 if (sr < 0)
677 dev_err(&client->dev, "%s: writing SR failed\n",
678 __func__);
679 else
680 handled = 1;
681 }
682
683 if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
684 dev_warn(&client->dev, "event detected");
685 handled = 1;
686 if (isl1208->config->has_timestamp)
687 sysfs_notify(&isl1208->rtc->dev.kobj, NULL,
688 dev_attr_timestamp0.attr.name);
689 }
690
691 return handled ? IRQ_HANDLED : IRQ_NONE;
692}
693
694static const struct rtc_class_ops isl1208_rtc_ops = {
695 .proc = isl1208_rtc_proc,
696 .read_time = isl1208_rtc_read_time,
697 .set_time = isl1208_rtc_set_time,
698 .read_alarm = isl1208_rtc_read_alarm,
699 .set_alarm = isl1208_rtc_set_alarm,
700};
701
702/* sysfs interface */
703
704static ssize_t
705isl1208_sysfs_show_atrim(struct device *dev,
706 struct device_attribute *attr, char *buf)
707{
708 int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent));
709 if (atr < 0)
710 return atr;
711
712 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
713}
714
715static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
716
717static ssize_t
718isl1208_sysfs_show_dtrim(struct device *dev,
719 struct device_attribute *attr, char *buf)
720{
721 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent));
722 if (dtr < 0)
723 return dtr;
724
725 return sprintf(buf, "%d ppm\n", dtr - 100);
726}
727
728static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
729
730static ssize_t
731isl1208_sysfs_show_usr(struct device *dev,
732 struct device_attribute *attr, char *buf)
733{
734 int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent));
735 if (usr < 0)
736 return usr;
737
738 return sprintf(buf, "0x%.4x\n", usr);
739}
740
741static ssize_t
742isl1208_sysfs_store_usr(struct device *dev,
743 struct device_attribute *attr,
744 const char *buf, size_t count)
745{
746 int usr = -1;
747
748 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
749 if (sscanf(buf, "%x", &usr) != 1)
750 return -EINVAL;
751 } else {
752 if (sscanf(buf, "%d", &usr) != 1)
753 return -EINVAL;
754 }
755
756 if (usr < 0 || usr > 0xffff)
757 return -EINVAL;
758
759 if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr))
760 return -EIO;
761
762 return count;
763}
764
765static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
766 isl1208_sysfs_store_usr);
767
768static struct attribute *isl1208_rtc_attrs[] = {
769 &dev_attr_atrim.attr,
770 &dev_attr_dtrim.attr,
771 &dev_attr_usr.attr,
772 NULL
773};
774
775static const struct attribute_group isl1208_rtc_sysfs_files = {
776 .attrs = isl1208_rtc_attrs,
777};
778
779static struct attribute *isl1219_rtc_attrs[] = {
780 &dev_attr_timestamp0.attr,
781 NULL
782};
783
784static const struct attribute_group isl1219_rtc_sysfs_files = {
785 .attrs = isl1219_rtc_attrs,
786};
787
788static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
789 size_t count)
790{
791 struct isl1208_state *isl1208 = priv;
792 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
793
794 /* nvmem sanitizes offset/count for us, but count==0 is possible */
795 if (!count)
796 return count;
797
798 return isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf,
799 count);
800}
801
802static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
803 size_t count)
804{
805 struct isl1208_state *isl1208 = priv;
806 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
807
808 /* nvmem sanitizes off/count for us, but count==0 is possible */
809 if (!count)
810 return count;
811
812 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf,
813 count);
814}
815
816static const struct nvmem_config isl1208_nvmem_config = {
817 .name = "isl1208_nvram",
818 .word_size = 1,
819 .stride = 1,
820 /* .size from chip specific config */
821 .reg_read = isl1208_nvmem_read,
822 .reg_write = isl1208_nvmem_write,
823};
824
825static int isl1208_setup_irq(struct i2c_client *client, int irq)
826{
827 int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
828 isl1208_rtc_interrupt,
829 IRQF_SHARED | IRQF_ONESHOT,
830 isl1208_driver.driver.name,
831 client);
832 if (!rc) {
833 device_init_wakeup(&client->dev, 1);
834 enable_irq_wake(irq);
835 } else {
836 dev_err(&client->dev,
837 "Unable to request irq %d, no alarm support\n",
838 irq);
839 }
840 return rc;
841}
842
843static int
844isl1208_clk_present(struct i2c_client *client, const char *name)
845{
846 struct clk *clk;
847
848 clk = devm_clk_get_optional(&client->dev, name);
849 if (IS_ERR(clk))
850 return PTR_ERR(clk);
851
852 return !!clk;
853}
854
855static int
856isl1208_probe(struct i2c_client *client)
857{
858 struct isl1208_state *isl1208;
859 int evdet_irq = -1;
860 int xtosb_val = 0;
861 int rc = 0;
862 int sr;
863
864 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
865 return -ENODEV;
866
867 if (isl1208_i2c_validate_client(client) < 0)
868 return -ENODEV;
869
870 /* Allocate driver state, point i2c client data to it */
871 isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL);
872 if (!isl1208)
873 return -ENOMEM;
874 i2c_set_clientdata(client, isl1208);
875
876 /* Determine which chip we have */
877 isl1208->config = i2c_get_match_data(client);
878 if (!isl1208->config)
879 return -ENODEV;
880
881 rc = isl1208_clk_present(client, "xin");
882 if (rc < 0)
883 return rc;
884
885 if (!rc) {
886 rc = isl1208_clk_present(client, "clkin");
887 if (rc < 0)
888 return rc;
889
890 if (rc)
891 xtosb_val = 1;
892 }
893
894 isl1208->rtc = devm_rtc_allocate_device(&client->dev);
895 if (IS_ERR(isl1208->rtc))
896 return PTR_ERR(isl1208->rtc);
897
898 isl1208->rtc->ops = &isl1208_rtc_ops;
899
900 /* Setup nvmem configuration in driver state struct */
901 isl1208->nvmem_config = isl1208_nvmem_config;
902 isl1208->nvmem_config.size = isl1208->config->nvmem_length;
903 isl1208->nvmem_config.priv = isl1208;
904
905 sr = isl1208_i2c_get_sr(client);
906 if (sr < 0) {
907 dev_err(&client->dev, "reading status failed\n");
908 return sr;
909 }
910
911 if (isl1208->config->has_inverted_osc_bit)
912 xtosb_val = !xtosb_val;
913
914 rc = isl1208_set_xtoscb(client, sr, xtosb_val);
915 if (rc)
916 return rc;
917
918 if (sr & ISL1208_REG_SR_RTCF)
919 dev_warn(&client->dev, "rtc power failure detected, "
920 "please set clock.\n");
921
922 if (isl1208->config->has_tamper) {
923 struct device_node *np = client->dev.of_node;
924 u32 evienb;
925
926 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
927 if (rc < 0) {
928 dev_err(&client->dev, "failed to read EV reg\n");
929 return rc;
930 }
931 rc |= ISL1219_REG_EV_EVEN;
932 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
933 if (evienb)
934 rc |= ISL1219_REG_EV_EVIENB;
935 else
936 rc &= ~ISL1219_REG_EV_EVIENB;
937 }
938 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
939 if (rc < 0) {
940 dev_err(&client->dev, "could not enable tamper detection\n");
941 return rc;
942 }
943 evdet_irq = of_irq_get_byname(np, "evdet");
944 }
945 if (isl1208->config->has_timestamp) {
946 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files);
947 if (rc)
948 return rc;
949 }
950
951 rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files);
952 if (rc)
953 return rc;
954
955 if (client->irq > 0) {
956 rc = isl1208_setup_irq(client, client->irq);
957 if (rc)
958 return rc;
959 } else {
960 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, isl1208->rtc->features);
961 }
962
963 if (evdet_irq > 0 && evdet_irq != client->irq)
964 rc = isl1208_setup_irq(client, evdet_irq);
965 if (rc)
966 return rc;
967
968 rc = devm_rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config);
969 if (rc)
970 return rc;
971
972 return devm_rtc_register_device(isl1208->rtc);
973}
974
975static struct i2c_driver isl1208_driver = {
976 .driver = {
977 .name = "rtc-isl1208",
978 .of_match_table = of_match_ptr(isl1208_of_match),
979 },
980 .probe = isl1208_probe,
981 .id_table = isl1208_id,
982};
983
984module_i2c_driver(isl1208_driver);
985
986MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
987MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
988MODULE_LICENSE("GPL");