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13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/bcd.h>
16#include <linux/rtc.h>
17
18
19
20#define ISL1208_REG_SC 0x00
21#define ISL1208_REG_MN 0x01
22#define ISL1208_REG_HR 0x02
23#define ISL1208_REG_HR_MIL (1<<7)
24#define ISL1208_REG_HR_PM (1<<5)
25#define ISL1208_REG_DT 0x03
26#define ISL1208_REG_MO 0x04
27#define ISL1208_REG_YR 0x05
28#define ISL1208_REG_DW 0x06
29#define ISL1208_RTC_SECTION_LEN 7
30
31
32#define ISL1208_REG_SR 0x07
33#define ISL1208_REG_SR_ARST (1<<7)
34#define ISL1208_REG_SR_XTOSCB (1<<6)
35#define ISL1208_REG_SR_WRTC (1<<4)
36#define ISL1208_REG_SR_ALM (1<<2)
37#define ISL1208_REG_SR_BAT (1<<1)
38#define ISL1208_REG_SR_RTCF (1<<0)
39#define ISL1208_REG_INT 0x08
40#define ISL1208_REG_INT_ALME (1<<6)
41#define ISL1208_REG_INT_IM (1<<7)
42#define ISL1208_REG_09 0x09
43#define ISL1208_REG_ATR 0x0a
44#define ISL1208_REG_DTR 0x0b
45
46
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
56#define ISL1208_REG_USR1 0x12
57#define ISL1208_REG_USR2 0x13
58#define ISL1208_USR_SECTION_LEN 2
59
60static struct i2c_driver isl1208_driver;
61
62
63static int
64isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
65 unsigned len)
66{
67 u8 reg_addr[1] = { reg };
68 struct i2c_msg msgs[2] = {
69 {
70 .addr = client->addr,
71 .len = sizeof(reg_addr),
72 .buf = reg_addr
73 },
74 {
75 .addr = client->addr,
76 .flags = I2C_M_RD,
77 .len = len,
78 .buf = buf
79 }
80 };
81 int ret;
82
83 BUG_ON(reg > ISL1208_REG_USR2);
84 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
85
86 ret = i2c_transfer(client->adapter, msgs, 2);
87 if (ret > 0)
88 ret = 0;
89 return ret;
90}
91
92
93static int
94isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
95 unsigned len)
96{
97 u8 i2c_buf[ISL1208_REG_USR2 + 2];
98 struct i2c_msg msgs[1] = {
99 {
100 .addr = client->addr,
101 .len = len + 1,
102 .buf = i2c_buf
103 }
104 };
105 int ret;
106
107 BUG_ON(reg > ISL1208_REG_USR2);
108 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
109
110 i2c_buf[0] = reg;
111 memcpy(&i2c_buf[1], &buf[0], len);
112
113 ret = i2c_transfer(client->adapter, msgs, 1);
114 if (ret > 0)
115 ret = 0;
116 return ret;
117}
118
119
120static int
121isl1208_i2c_validate_client(struct i2c_client *client)
122{
123 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
124 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
125 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
126 };
127 int i;
128 int ret;
129
130 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
131 if (ret < 0)
132 return ret;
133
134 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
135 if (regs[i] & zero_mask[i])
136 return -ENODEV;
137 }
138
139 return 0;
140}
141
142static int
143isl1208_i2c_get_sr(struct i2c_client *client)
144{
145 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
146}
147
148static int
149isl1208_i2c_get_atr(struct i2c_client *client)
150{
151 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
152 if (atr < 0)
153 return atr;
154
155
156
157
158
159
160
161
162
163
164
165
166 atr &= 0x3f;
167 atr ^= 1 << 5;
168 atr += 2 * 9;
169
170 return atr;
171}
172
173static int
174isl1208_i2c_get_dtr(struct i2c_client *client)
175{
176 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
177 if (dtr < 0)
178 return -EIO;
179
180
181 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
182
183 return dtr;
184}
185
186static int
187isl1208_i2c_get_usr(struct i2c_client *client)
188{
189 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
190 int ret;
191
192 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
193 ISL1208_USR_SECTION_LEN);
194 if (ret < 0)
195 return ret;
196
197 return (buf[1] << 8) | buf[0];
198}
199
200static int
201isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
202{
203 u8 buf[ISL1208_USR_SECTION_LEN];
204
205 buf[0] = usr & 0xff;
206 buf[1] = (usr >> 8) & 0xff;
207
208 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
209 ISL1208_USR_SECTION_LEN);
210}
211
212static int
213isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
214{
215 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
216
217 if (icr < 0) {
218 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
219 return icr;
220 }
221
222 if (enable)
223 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
224 else
225 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
226
227 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
228 if (icr < 0) {
229 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
230 return icr;
231 }
232
233 return 0;
234}
235
236static int
237isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
238{
239 struct i2c_client *const client = to_i2c_client(dev);
240 int sr, dtr, atr, usr;
241
242 sr = isl1208_i2c_get_sr(client);
243 if (sr < 0) {
244 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
245 return sr;
246 }
247
248 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
249 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
250 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
251 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
252 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
253 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
254 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
255
256 seq_printf(seq, "batt_status\t: %s\n",
257 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
258
259 dtr = isl1208_i2c_get_dtr(client);
260 if (dtr >= 0 - 1)
261 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
262
263 atr = isl1208_i2c_get_atr(client);
264 if (atr >= 0)
265 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
266 atr >> 2, (atr & 0x3) * 25);
267
268 usr = isl1208_i2c_get_usr(client);
269 if (usr >= 0)
270 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
271
272 return 0;
273}
274
275static int
276isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
277{
278 int sr;
279 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
280
281 sr = isl1208_i2c_get_sr(client);
282 if (sr < 0) {
283 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
284 return -EIO;
285 }
286
287 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
288 if (sr < 0) {
289 dev_err(&client->dev, "%s: reading RTC section failed\n",
290 __func__);
291 return sr;
292 }
293
294 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
295 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
296
297
298 {
299 const u8 _hr = regs[ISL1208_REG_HR];
300 if (_hr & ISL1208_REG_HR_MIL)
301 tm->tm_hour = bcd2bin(_hr & 0x3f);
302 else {
303
304 tm->tm_hour = bcd2bin(_hr & 0x1f);
305 if (_hr & ISL1208_REG_HR_PM)
306 tm->tm_hour += 12;
307 }
308 }
309
310 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
311 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1;
312 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
313 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
314
315 return 0;
316}
317
318static int
319isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
320{
321 struct rtc_time *const tm = &alarm->time;
322 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
323 int icr, yr, sr = isl1208_i2c_get_sr(client);
324
325 if (sr < 0) {
326 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
327 return sr;
328 }
329
330 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
331 ISL1208_ALARM_SECTION_LEN);
332 if (sr < 0) {
333 dev_err(&client->dev, "%s: reading alarm section failed\n",
334 __func__);
335 return sr;
336 }
337
338
339 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
340 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
341 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
342 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
343 tm->tm_mon =
344 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
345 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
346
347
348 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
349 if (yr < 0) {
350 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
351 return yr;
352 }
353 tm->tm_year = bcd2bin(yr) + 100;
354
355 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
356 if (icr < 0) {
357 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
358 return icr;
359 }
360 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
361
362 return 0;
363}
364
365static int
366isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
367{
368 struct rtc_time *alarm_tm = &alarm->time;
369 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
370 const int offs = ISL1208_REG_SCA;
371 struct rtc_time rtc_tm;
372 int err, enable;
373
374 err = isl1208_i2c_read_time(client, &rtc_tm);
375 if (err)
376 return err;
377
378
379 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
380 enable = 0x00;
381 else
382 enable = 0x80;
383
384
385 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
386 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
387 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
388 ISL1208_REG_HR_MIL | enable;
389
390 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
391 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
392 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
393
394
395 err = isl1208_i2c_set_regs(client, offs, regs,
396 ISL1208_ALARM_SECTION_LEN);
397 if (err < 0) {
398 dev_err(&client->dev, "%s: writing ALARM section failed\n",
399 __func__);
400 return err;
401 }
402
403 err = isl1208_rtc_toggle_alarm(client, enable);
404 if (err)
405 return err;
406
407 return 0;
408}
409
410static int
411isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
412{
413 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
414}
415
416static int
417isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
418{
419 int sr;
420 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
421
422
423
424
425
426 if (tm->tm_year < 100)
427 return -EINVAL;
428
429 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
430 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
431 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
432
433 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
434 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
435 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
436
437 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
438
439 sr = isl1208_i2c_get_sr(client);
440 if (sr < 0) {
441 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
442 return sr;
443 }
444
445
446 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
447 sr | ISL1208_REG_SR_WRTC);
448 if (sr < 0) {
449 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
450 return sr;
451 }
452
453
454 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
455 if (sr < 0) {
456 dev_err(&client->dev, "%s: writing RTC section failed\n",
457 __func__);
458 return sr;
459 }
460
461
462 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
463 sr & ~ISL1208_REG_SR_WRTC);
464 if (sr < 0) {
465 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
466 return sr;
467 }
468
469 return 0;
470}
471
472
473static int
474isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
475{
476 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
477}
478
479static int
480isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
481{
482 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
483}
484
485static int
486isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
487{
488 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
489}
490
491static irqreturn_t
492isl1208_rtc_interrupt(int irq, void *data)
493{
494 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
495 struct i2c_client *client = data;
496 struct rtc_device *rtc = i2c_get_clientdata(client);
497 int handled = 0, sr, err;
498
499
500
501
502
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 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
520
521
522 sr &= ~ISL1208_REG_SR_ALM;
523 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
524 if (sr < 0)
525 dev_err(&client->dev, "%s: writing SR failed\n",
526 __func__);
527 else
528 handled = 1;
529
530
531 err = isl1208_rtc_toggle_alarm(client, 0);
532 if (err)
533 return err;
534 }
535
536 return handled ? IRQ_HANDLED : IRQ_NONE;
537}
538
539static const struct rtc_class_ops isl1208_rtc_ops = {
540 .proc = isl1208_rtc_proc,
541 .read_time = isl1208_rtc_read_time,
542 .set_time = isl1208_rtc_set_time,
543 .read_alarm = isl1208_rtc_read_alarm,
544 .set_alarm = isl1208_rtc_set_alarm,
545};
546
547
548
549static ssize_t
550isl1208_sysfs_show_atrim(struct device *dev,
551 struct device_attribute *attr, char *buf)
552{
553 int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
554 if (atr < 0)
555 return atr;
556
557 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
558}
559
560static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
561
562static ssize_t
563isl1208_sysfs_show_dtrim(struct device *dev,
564 struct device_attribute *attr, char *buf)
565{
566 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
567 if (dtr < 0)
568 return dtr;
569
570 return sprintf(buf, "%d ppm\n", dtr);
571}
572
573static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
574
575static ssize_t
576isl1208_sysfs_show_usr(struct device *dev,
577 struct device_attribute *attr, char *buf)
578{
579 int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
580 if (usr < 0)
581 return usr;
582
583 return sprintf(buf, "0x%.4x\n", usr);
584}
585
586static ssize_t
587isl1208_sysfs_store_usr(struct device *dev,
588 struct device_attribute *attr,
589 const char *buf, size_t count)
590{
591 int usr = -1;
592
593 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
594 if (sscanf(buf, "%x", &usr) != 1)
595 return -EINVAL;
596 } else {
597 if (sscanf(buf, "%d", &usr) != 1)
598 return -EINVAL;
599 }
600
601 if (usr < 0 || usr > 0xffff)
602 return -EINVAL;
603
604 return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
605}
606
607static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
608 isl1208_sysfs_store_usr);
609
610static struct attribute *isl1208_rtc_attrs[] = {
611 &dev_attr_atrim.attr,
612 &dev_attr_dtrim.attr,
613 &dev_attr_usr.attr,
614 NULL
615};
616
617static const struct attribute_group isl1208_rtc_sysfs_files = {
618 .attrs = isl1208_rtc_attrs,
619};
620
621static int
622isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
623{
624 int rc = 0;
625 struct rtc_device *rtc;
626
627 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
628 return -ENODEV;
629
630 if (isl1208_i2c_validate_client(client) < 0)
631 return -ENODEV;
632
633 if (client->irq > 0) {
634 rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,
635 isl1208_rtc_interrupt,
636 IRQF_SHARED | IRQF_ONESHOT,
637 isl1208_driver.driver.name,
638 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 = devm_rtc_device_register(&client->dev, isl1208_driver.driver.name,
651 &isl1208_rtc_ops,
652 THIS_MODULE);
653 if (IS_ERR(rtc))
654 return PTR_ERR(rtc);
655
656 i2c_set_clientdata(client, rtc);
657
658 rc = isl1208_i2c_get_sr(client);
659 if (rc < 0) {
660 dev_err(&client->dev, "reading status failed\n");
661 return rc;
662 }
663
664 if (rc & ISL1208_REG_SR_RTCF)
665 dev_warn(&client->dev, "rtc power failure detected, "
666 "please set clock.\n");
667
668 rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
669 if (rc)
670 return rc;
671
672 return 0;
673}
674
675static int
676isl1208_remove(struct i2c_client *client)
677{
678 sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
679
680 return 0;
681}
682
683static const struct i2c_device_id isl1208_id[] = {
684 { "isl1208", 0 },
685 { "isl1218", 0 },
686 { }
687};
688MODULE_DEVICE_TABLE(i2c, isl1208_id);
689
690static const struct of_device_id isl1208_of_match[] = {
691 { .compatible = "isil,isl1208" },
692 { .compatible = "isil,isl1218" },
693 { }
694};
695MODULE_DEVICE_TABLE(of, isl1208_of_match);
696
697static struct i2c_driver isl1208_driver = {
698 .driver = {
699 .name = "rtc-isl1208",
700 .of_match_table = of_match_ptr(isl1208_of_match),
701 },
702 .probe = isl1208_probe,
703 .remove = isl1208_remove,
704 .id_table = isl1208_id,
705};
706
707module_i2c_driver(isl1208_driver);
708
709MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
710MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
711MODULE_LICENSE("GPL");
712
