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1/*
2 * Intersil ISL1208 rtc class driver
3 *
4 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 */
12
13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/bcd.h>
16#include <linux/rtc.h>
17
18#define DRV_VERSION "0.3"
19
20/* Register map */
21/* rtc section */
22#define ISL1208_REG_SC 0x00
23#define ISL1208_REG_MN 0x01
24#define ISL1208_REG_HR 0x02
25#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
26#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
27#define ISL1208_REG_DT 0x03
28#define ISL1208_REG_MO 0x04
29#define ISL1208_REG_YR 0x05
30#define ISL1208_REG_DW 0x06
31#define ISL1208_RTC_SECTION_LEN 7
32
33/* control/status section */
34#define ISL1208_REG_SR 0x07
35#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
36#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
37#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
38#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
39#define ISL1208_REG_SR_BAT (1<<1) /* battery */
40#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
41#define ISL1208_REG_INT 0x08
42#define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
43#define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
44#define ISL1208_REG_09 0x09 /* reserved */
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
62static struct i2c_driver isl1208_driver;
63
64/* block read */
65static int
66isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
67 unsigned len)
68{
69 u8 reg_addr[1] = { reg };
70 struct i2c_msg msgs[2] = {
71 {client->addr, 0, sizeof(reg_addr), reg_addr}
72 ,
73 {client->addr, I2C_M_RD, len, buf}
74 };
75 int ret;
76
77 BUG_ON(reg > ISL1208_REG_USR2);
78 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
79
80 ret = i2c_transfer(client->adapter, msgs, 2);
81 if (ret > 0)
82 ret = 0;
83 return ret;
84}
85
86/* block write */
87static int
88isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
89 unsigned len)
90{
91 u8 i2c_buf[ISL1208_REG_USR2 + 2];
92 struct i2c_msg msgs[1] = {
93 {client->addr, 0, len + 1, i2c_buf}
94 };
95 int ret;
96
97 BUG_ON(reg > ISL1208_REG_USR2);
98 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
99
100 i2c_buf[0] = reg;
101 memcpy(&i2c_buf[1], &buf[0], len);
102
103 ret = i2c_transfer(client->adapter, msgs, 1);
104 if (ret > 0)
105 ret = 0;
106 return ret;
107}
108
109/* simple check to see wether we have a isl1208 */
110static int
111isl1208_i2c_validate_client(struct i2c_client *client)
112{
113 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
114 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
115 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
116 };
117 int i;
118 int ret;
119
120 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
121 if (ret < 0)
122 return ret;
123
124 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
125 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
126 return -ENODEV;
127 }
128
129 return 0;
130}
131
132static int
133isl1208_i2c_get_sr(struct i2c_client *client)
134{
135 int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
136 if (sr < 0)
137 return -EIO;
138
139 return sr;
140}
141
142static int
143isl1208_i2c_get_atr(struct i2c_client *client)
144{
145 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
146 if (atr < 0)
147 return atr;
148
149 /* The 6bit value in the ATR register controls the load
150 * capacitance C_load * in steps of 0.25pF
151 *
152 * bit (1<<5) of the ATR register is inverted
153 *
154 * C_load(ATR=0x20) = 4.50pF
155 * C_load(ATR=0x00) = 12.50pF
156 * C_load(ATR=0x1f) = 20.25pF
157 *
158 */
159
160 atr &= 0x3f; /* mask out lsb */
161 atr ^= 1 << 5; /* invert 6th bit */
162 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
163
164 return atr;
165}
166
167static int
168isl1208_i2c_get_dtr(struct i2c_client *client)
169{
170 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
171 if (dtr < 0)
172 return -EIO;
173
174 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
175 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
176
177 return dtr;
178}
179
180static int
181isl1208_i2c_get_usr(struct i2c_client *client)
182{
183 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
184 int ret;
185
186 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
187 ISL1208_USR_SECTION_LEN);
188 if (ret < 0)
189 return ret;
190
191 return (buf[1] << 8) | buf[0];
192}
193
194static int
195isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
196{
197 u8 buf[ISL1208_USR_SECTION_LEN];
198
199 buf[0] = usr & 0xff;
200 buf[1] = (usr >> 8) & 0xff;
201
202 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
203 ISL1208_USR_SECTION_LEN);
204}
205
206static int
207isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
208{
209 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
210
211 if (icr < 0) {
212 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
213 return icr;
214 }
215
216 if (enable)
217 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
218 else
219 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
220
221 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
222 if (icr < 0) {
223 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
224 return icr;
225 }
226
227 return 0;
228}
229
230static int
231isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
232{
233 struct i2c_client *const client = to_i2c_client(dev);
234 int sr, dtr, atr, usr;
235
236 sr = isl1208_i2c_get_sr(client);
237 if (sr < 0) {
238 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
239 return sr;
240 }
241
242 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
243 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
244 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
245 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
246 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
247 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
248 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
249
250 seq_printf(seq, "batt_status\t: %s\n",
251 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
252
253 dtr = isl1208_i2c_get_dtr(client);
254 if (dtr >= 0 - 1)
255 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
256
257 atr = isl1208_i2c_get_atr(client);
258 if (atr >= 0)
259 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
260 atr >> 2, (atr & 0x3) * 25);
261
262 usr = isl1208_i2c_get_usr(client);
263 if (usr >= 0)
264 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
265
266 return 0;
267}
268
269static int
270isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
271{
272 int sr;
273 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
274
275 sr = isl1208_i2c_get_sr(client);
276 if (sr < 0) {
277 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
278 return -EIO;
279 }
280
281 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
282 if (sr < 0) {
283 dev_err(&client->dev, "%s: reading RTC section failed\n",
284 __func__);
285 return sr;
286 }
287
288 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
289 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
290
291 /* HR field has a more complex interpretation */
292 {
293 const u8 _hr = regs[ISL1208_REG_HR];
294 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
295 tm->tm_hour = bcd2bin(_hr & 0x3f);
296 else {
297 /* 12h format */
298 tm->tm_hour = bcd2bin(_hr & 0x1f);
299 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
300 tm->tm_hour += 12;
301 }
302 }
303
304 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
305 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
306 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
307 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
308
309 return 0;
310}
311
312static int
313isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
314{
315 struct rtc_time *const tm = &alarm->time;
316 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
317 int icr, yr, sr = isl1208_i2c_get_sr(client);
318
319 if (sr < 0) {
320 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
321 return sr;
322 }
323
324 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
325 ISL1208_ALARM_SECTION_LEN);
326 if (sr < 0) {
327 dev_err(&client->dev, "%s: reading alarm section failed\n",
328 __func__);
329 return sr;
330 }
331
332 /* MSB of each alarm register is an enable bit */
333 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
334 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
335 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
336 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
337 tm->tm_mon =
338 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
339 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
340
341 /* The alarm doesn't store the year so get it from the rtc section */
342 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
343 if (yr < 0) {
344 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
345 return yr;
346 }
347 tm->tm_year = bcd2bin(yr) + 100;
348
349 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
350 if (icr < 0) {
351 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
352 return icr;
353 }
354 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
355
356 return 0;
357}
358
359static int
360isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
361{
362 struct rtc_time *alarm_tm = &alarm->time;
363 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
364 const int offs = ISL1208_REG_SCA;
365 unsigned long rtc_secs, alarm_secs;
366 struct rtc_time rtc_tm;
367 int err, enable;
368
369 err = isl1208_i2c_read_time(client, &rtc_tm);
370 if (err)
371 return err;
372 err = rtc_tm_to_time(&rtc_tm, &rtc_secs);
373 if (err)
374 return err;
375 err = rtc_tm_to_time(alarm_tm, &alarm_secs);
376 if (err)
377 return err;
378
379 /* If the alarm time is before the current time disable the alarm */
380 if (!alarm->enabled || alarm_secs <= rtc_secs)
381 enable = 0x00;
382 else
383 enable = 0x80;
384
385 /* Program the alarm and enable it for each setting */
386 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
387 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
388 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
389 ISL1208_REG_HR_MIL | enable;
390
391 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
392 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
393 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
394
395 /* write ALARM registers */
396 err = isl1208_i2c_set_regs(client, offs, regs,
397 ISL1208_ALARM_SECTION_LEN);
398 if (err < 0) {
399 dev_err(&client->dev, "%s: writing ALARM section failed\n",
400 __func__);
401 return err;
402 }
403
404 err = isl1208_rtc_toggle_alarm(client, enable);
405 if (err)
406 return err;
407
408 return 0;
409}
410
411static int
412isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
413{
414 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
415}
416
417static int
418isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
419{
420 int sr;
421 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
422
423 /* The clock has an 8 bit wide bcd-coded register (they never learn)
424 * for the year. tm_year is an offset from 1900 and we are interested
425 * in the 2000-2099 range, so any value less than 100 is invalid.
426 */
427 if (tm->tm_year < 100)
428 return -EINVAL;
429
430 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
431 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
432 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
433
434 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
435 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
436 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
437
438 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
439
440 sr = isl1208_i2c_get_sr(client);
441 if (sr < 0) {
442 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
443 return sr;
444 }
445
446 /* set WRTC */
447 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
448 sr | ISL1208_REG_SR_WRTC);
449 if (sr < 0) {
450 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
451 return sr;
452 }
453
454 /* write RTC registers */
455 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
456 if (sr < 0) {
457 dev_err(&client->dev, "%s: writing RTC section failed\n",
458 __func__);
459 return sr;
460 }
461
462 /* clear WRTC again */
463 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
464 sr & ~ISL1208_REG_SR_WRTC);
465 if (sr < 0) {
466 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
467 return sr;
468 }
469
470 return 0;
471}
472
473
474static int
475isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
476{
477 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
478}
479
480static int
481isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
482{
483 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
484}
485
486static int
487isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
488{
489 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
490}
491
492static irqreturn_t
493isl1208_rtc_interrupt(int irq, void *data)
494{
495 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
496 struct i2c_client *client = data;
497 int handled = 0, sr, err;
498
499 /*
500 * I2C reads get NAK'ed if we read straight away after an interrupt?
501 * Using a mdelay/msleep didn't seem to help either, so we work around
502 * this by continually trying to read the register for a short time.
503 */
504 while (1) {
505 sr = isl1208_i2c_get_sr(client);
506 if (sr >= 0)
507 break;
508
509 if (time_after(jiffies, timeout)) {
510 dev_err(&client->dev, "%s: reading SR failed\n",
511 __func__);
512 return sr;
513 }
514 }
515
516 if (sr & ISL1208_REG_SR_ALM) {
517 dev_dbg(&client->dev, "alarm!\n");
518
519 /* Clear the alarm */
520 sr &= ~ISL1208_REG_SR_ALM;
521 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
522 if (sr < 0)
523 dev_err(&client->dev, "%s: writing SR failed\n",
524 __func__);
525 else
526 handled = 1;
527
528 /* Disable the alarm */
529 err = isl1208_rtc_toggle_alarm(client, 0);
530 if (err)
531 return err;
532 }
533
534 return handled ? IRQ_HANDLED : IRQ_NONE;
535}
536
537static const struct rtc_class_ops isl1208_rtc_ops = {
538 .proc = isl1208_rtc_proc,
539 .read_time = isl1208_rtc_read_time,
540 .set_time = isl1208_rtc_set_time,
541 .read_alarm = isl1208_rtc_read_alarm,
542 .set_alarm = isl1208_rtc_set_alarm,
543};
544
545/* sysfs interface */
546
547static ssize_t
548isl1208_sysfs_show_atrim(struct device *dev,
549 struct device_attribute *attr, char *buf)
550{
551 int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
552 if (atr < 0)
553 return atr;
554
555 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
556}
557
558static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
559
560static ssize_t
561isl1208_sysfs_show_dtrim(struct device *dev,
562 struct device_attribute *attr, char *buf)
563{
564 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
565 if (dtr < 0)
566 return dtr;
567
568 return sprintf(buf, "%d ppm\n", dtr);
569}
570
571static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
572
573static ssize_t
574isl1208_sysfs_show_usr(struct device *dev,
575 struct device_attribute *attr, char *buf)
576{
577 int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
578 if (usr < 0)
579 return usr;
580
581 return sprintf(buf, "0x%.4x\n", usr);
582}
583
584static ssize_t
585isl1208_sysfs_store_usr(struct device *dev,
586 struct device_attribute *attr,
587 const char *buf, size_t count)
588{
589 int usr = -1;
590
591 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
592 if (sscanf(buf, "%x", &usr) != 1)
593 return -EINVAL;
594 } else {
595 if (sscanf(buf, "%d", &usr) != 1)
596 return -EINVAL;
597 }
598
599 if (usr < 0 || usr > 0xffff)
600 return -EINVAL;
601
602 return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
603}
604
605static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
606 isl1208_sysfs_store_usr);
607
608static struct attribute *isl1208_rtc_attrs[] = {
609 &dev_attr_atrim.attr,
610 &dev_attr_dtrim.attr,
611 &dev_attr_usr.attr,
612 NULL
613};
614
615static const struct attribute_group isl1208_rtc_sysfs_files = {
616 .attrs = isl1208_rtc_attrs,
617};
618
619static int
620isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
621{
622 int rc = 0;
623 struct rtc_device *rtc;
624
625 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
626 return -ENODEV;
627
628 if (isl1208_i2c_validate_client(client) < 0)
629 return -ENODEV;
630
631 dev_info(&client->dev,
632 "chip found, driver version " DRV_VERSION "\n");
633
634 if (client->irq > 0) {
635 rc = request_threaded_irq(client->irq, NULL,
636 isl1208_rtc_interrupt,
637 IRQF_SHARED,
638 isl1208_driver.driver.name, client);
639 if (!rc) {
640 device_init_wakeup(&client->dev, 1);
641 enable_irq_wake(client->irq);
642 } else {
643 dev_err(&client->dev,
644 "Unable to request irq %d, no alarm support\n",
645 client->irq);
646 client->irq = 0;
647 }
648 }
649
650 rtc = rtc_device_register(isl1208_driver.driver.name,
651 &client->dev, &isl1208_rtc_ops,
652 THIS_MODULE);
653 if (IS_ERR(rtc)) {
654 rc = PTR_ERR(rtc);
655 goto exit_free_irq;
656 }
657
658 i2c_set_clientdata(client, rtc);
659
660 rc = isl1208_i2c_get_sr(client);
661 if (rc < 0) {
662 dev_err(&client->dev, "reading status failed\n");
663 goto exit_unregister;
664 }
665
666 if (rc & ISL1208_REG_SR_RTCF)
667 dev_warn(&client->dev, "rtc power failure detected, "
668 "please set clock.\n");
669
670 rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
671 if (rc)
672 goto exit_unregister;
673
674 return 0;
675
676exit_unregister:
677 rtc_device_unregister(rtc);
678exit_free_irq:
679 if (client->irq)
680 free_irq(client->irq, client);
681
682 return rc;
683}
684
685static int
686isl1208_remove(struct i2c_client *client)
687{
688 struct rtc_device *rtc = i2c_get_clientdata(client);
689
690 sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
691 rtc_device_unregister(rtc);
692 if (client->irq)
693 free_irq(client->irq, client);
694
695 return 0;
696}
697
698static const struct i2c_device_id isl1208_id[] = {
699 { "isl1208", 0 },
700 { }
701};
702MODULE_DEVICE_TABLE(i2c, isl1208_id);
703
704static struct i2c_driver isl1208_driver = {
705 .driver = {
706 .name = "rtc-isl1208",
707 },
708 .probe = isl1208_probe,
709 .remove = isl1208_remove,
710 .id_table = isl1208_id,
711};
712
713static int __init
714isl1208_init(void)
715{
716 return i2c_add_driver(&isl1208_driver);
717}
718
719static void __exit
720isl1208_exit(void)
721{
722 i2c_del_driver(&isl1208_driver);
723}
724
725MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
726MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
727MODULE_LICENSE("GPL");
728MODULE_VERSION(DRV_VERSION);
729
730module_init(isl1208_init);
731module_exit(isl1208_exit);
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");