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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#define DRV_VERSION "0.3"
19
20
21
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)
26#define ISL1208_REG_HR_PM (1<<5)
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
34#define ISL1208_REG_SR 0x07
35#define ISL1208_REG_SR_ARST (1<<7)
36#define ISL1208_REG_SR_XTOSCB (1<<6)
37#define ISL1208_REG_SR_WRTC (1<<4)
38#define ISL1208_REG_SR_ALM (1<<2)
39#define ISL1208_REG_SR_BAT (1<<1)
40#define ISL1208_REG_SR_RTCF (1<<0)
41#define ISL1208_REG_INT 0x08
42#define ISL1208_REG_INT_ALME (1<<6)
43#define ISL1208_REG_INT_IM (1<<7)
44#define ISL1208_REG_09 0x09
45#define ISL1208_REG_ATR 0x0a
46#define ISL1208_REG_DTR 0x0b
47
48
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
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
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 {
72 .addr = client->addr,
73 .len = sizeof(reg_addr),
74 .buf = reg_addr
75 },
76 {
77 .addr = client->addr,
78 .flags = I2C_M_RD,
79 .len = len,
80 .buf = buf
81 }
82 };
83 int ret;
84
85 BUG_ON(reg > ISL1208_REG_USR2);
86 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
87
88 ret = i2c_transfer(client->adapter, msgs, 2);
89 if (ret > 0)
90 ret = 0;
91 return ret;
92}
93
94
95static int
96isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
97 unsigned len)
98{
99 u8 i2c_buf[ISL1208_REG_USR2 + 2];
100 struct i2c_msg msgs[1] = {
101 {
102 .addr = client->addr,
103 .len = len + 1,
104 .buf = i2c_buf
105 }
106 };
107 int ret;
108
109 BUG_ON(reg > ISL1208_REG_USR2);
110 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
111
112 i2c_buf[0] = reg;
113 memcpy(&i2c_buf[1], &buf[0], len);
114
115 ret = i2c_transfer(client->adapter, msgs, 1);
116 if (ret > 0)
117 ret = 0;
118 return ret;
119}
120
121
122static int
123isl1208_i2c_validate_client(struct i2c_client *client)
124{
125 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
126 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
127 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
128 };
129 int i;
130 int ret;
131
132 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
133 if (ret < 0)
134 return ret;
135
136 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
137 if (regs[i] & zero_mask[i])
138 return -ENODEV;
139 }
140
141 return 0;
142}
143
144static int
145isl1208_i2c_get_sr(struct i2c_client *client)
146{
147 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
148}
149
150static int
151isl1208_i2c_get_atr(struct i2c_client *client)
152{
153 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
154 if (atr < 0)
155 return atr;
156
157
158
159
160
161
162
163
164
165
166
167
168 atr &= 0x3f;
169 atr ^= 1 << 5;
170 atr += 2 * 9;
171
172 return atr;
173}
174
175static int
176isl1208_i2c_get_dtr(struct i2c_client *client)
177{
178 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
179 if (dtr < 0)
180 return -EIO;
181
182
183 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
184
185 return dtr;
186}
187
188static int
189isl1208_i2c_get_usr(struct i2c_client *client)
190{
191 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
192 int ret;
193
194 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
195 ISL1208_USR_SECTION_LEN);
196 if (ret < 0)
197 return ret;
198
199 return (buf[1] << 8) | buf[0];
200}
201
202static int
203isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
204{
205 u8 buf[ISL1208_USR_SECTION_LEN];
206
207 buf[0] = usr & 0xff;
208 buf[1] = (usr >> 8) & 0xff;
209
210 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
211 ISL1208_USR_SECTION_LEN);
212}
213
214static int
215isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
216{
217 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
218
219 if (icr < 0) {
220 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
221 return icr;
222 }
223
224 if (enable)
225 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
226 else
227 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
228
229 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
230 if (icr < 0) {
231 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
232 return icr;
233 }
234
235 return 0;
236}
237
238static int
239isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
240{
241 struct i2c_client *const client = to_i2c_client(dev);
242 int sr, dtr, atr, usr;
243
244 sr = isl1208_i2c_get_sr(client);
245 if (sr < 0) {
246 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
247 return sr;
248 }
249
250 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
251 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
252 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
253 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
254 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
255 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
256 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
257
258 seq_printf(seq, "batt_status\t: %s\n",
259 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
260
261 dtr = isl1208_i2c_get_dtr(client);
262 if (dtr >= 0 - 1)
263 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
264
265 atr = isl1208_i2c_get_atr(client);
266 if (atr >= 0)
267 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
268 atr >> 2, (atr & 0x3) * 25);
269
270 usr = isl1208_i2c_get_usr(client);
271 if (usr >= 0)
272 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
273
274 return 0;
275}
276
277static int
278isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
279{
280 int sr;
281 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
282
283 sr = isl1208_i2c_get_sr(client);
284 if (sr < 0) {
285 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
286 return -EIO;
287 }
288
289 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
290 if (sr < 0) {
291 dev_err(&client->dev, "%s: reading RTC section failed\n",
292 __func__);
293 return sr;
294 }
295
296 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
297 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
298
299
300 {
301 const u8 _hr = regs[ISL1208_REG_HR];
302 if (_hr & ISL1208_REG_HR_MIL)
303 tm->tm_hour = bcd2bin(_hr & 0x3f);
304 else {
305
306 tm->tm_hour = bcd2bin(_hr & 0x1f);
307 if (_hr & ISL1208_REG_HR_PM)
308 tm->tm_hour += 12;
309 }
310 }
311
312 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
313 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1;
314 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
315 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
316
317 return 0;
318}
319
320static int
321isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
322{
323 struct rtc_time *const tm = &alarm->time;
324 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
325 int icr, yr, sr = isl1208_i2c_get_sr(client);
326
327 if (sr < 0) {
328 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
329 return sr;
330 }
331
332 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
333 ISL1208_ALARM_SECTION_LEN);
334 if (sr < 0) {
335 dev_err(&client->dev, "%s: reading alarm section failed\n",
336 __func__);
337 return sr;
338 }
339
340
341 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
342 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
343 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
344 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
345 tm->tm_mon =
346 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
347 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
348
349
350 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
351 if (yr < 0) {
352 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
353 return yr;
354 }
355 tm->tm_year = bcd2bin(yr) + 100;
356
357 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
358 if (icr < 0) {
359 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
360 return icr;
361 }
362 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
363
364 return 0;
365}
366
367static int
368isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
369{
370 struct rtc_time *alarm_tm = &alarm->time;
371 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
372 const int offs = ISL1208_REG_SCA;
373 unsigned long rtc_secs, alarm_secs;
374 struct rtc_time rtc_tm;
375 int err, enable;
376
377 err = isl1208_i2c_read_time(client, &rtc_tm);
378 if (err)
379 return err;
380 err = rtc_tm_to_time(&rtc_tm, &rtc_secs);
381 if (err)
382 return err;
383 err = rtc_tm_to_time(alarm_tm, &alarm_secs);
384 if (err)
385 return err;
386
387
388 if (!alarm->enabled || alarm_secs <= rtc_secs)
389 enable = 0x00;
390 else
391 enable = 0x80;
392
393
394 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
395 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
396 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
397 ISL1208_REG_HR_MIL | enable;
398
399 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
400 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
401 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
402
403
404 err = isl1208_i2c_set_regs(client, offs, regs,
405 ISL1208_ALARM_SECTION_LEN);
406 if (err < 0) {
407 dev_err(&client->dev, "%s: writing ALARM section failed\n",
408 __func__);
409 return err;
410 }
411
412 err = isl1208_rtc_toggle_alarm(client, enable);
413 if (err)
414 return err;
415
416 return 0;
417}
418
419static int
420isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
421{
422 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
423}
424
425static int
426isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
427{
428 int sr;
429 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
430
431
432
433
434
435 if (tm->tm_year < 100)
436 return -EINVAL;
437
438 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
439 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
440 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
441
442 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
443 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
444 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
445
446 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
447
448 sr = isl1208_i2c_get_sr(client);
449 if (sr < 0) {
450 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
451 return sr;
452 }
453
454
455 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
456 sr | ISL1208_REG_SR_WRTC);
457 if (sr < 0) {
458 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
459 return sr;
460 }
461
462
463 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
464 if (sr < 0) {
465 dev_err(&client->dev, "%s: writing RTC section failed\n",
466 __func__);
467 return sr;
468 }
469
470
471 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
472 sr & ~ISL1208_REG_SR_WRTC);
473 if (sr < 0) {
474 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
475 return sr;
476 }
477
478 return 0;
479}
480
481
482static int
483isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
484{
485 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
486}
487
488static int
489isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
490{
491 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
492}
493
494static int
495isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
496{
497 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
498}
499
500static irqreturn_t
501isl1208_rtc_interrupt(int irq, void *data)
502{
503 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
504 struct i2c_client *client = data;
505 struct rtc_device *rtc = i2c_get_clientdata(client);
506 int handled = 0, sr, err;
507
508
509
510
511
512
513 while (1) {
514 sr = isl1208_i2c_get_sr(client);
515 if (sr >= 0)
516 break;
517
518 if (time_after(jiffies, timeout)) {
519 dev_err(&client->dev, "%s: reading SR failed\n",
520 __func__);
521 return sr;
522 }
523 }
524
525 if (sr & ISL1208_REG_SR_ALM) {
526 dev_dbg(&client->dev, "alarm!\n");
527
528 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
529
530
531 sr &= ~ISL1208_REG_SR_ALM;
532 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
533 if (sr < 0)
534 dev_err(&client->dev, "%s: writing SR failed\n",
535 __func__);
536 else
537 handled = 1;
538
539
540 err = isl1208_rtc_toggle_alarm(client, 0);
541 if (err)
542 return err;
543 }
544
545 return handled ? IRQ_HANDLED : IRQ_NONE;
546}
547
548static const struct rtc_class_ops isl1208_rtc_ops = {
549 .proc = isl1208_rtc_proc,
550 .read_time = isl1208_rtc_read_time,
551 .set_time = isl1208_rtc_set_time,
552 .read_alarm = isl1208_rtc_read_alarm,
553 .set_alarm = isl1208_rtc_set_alarm,
554};
555
556
557
558static ssize_t
559isl1208_sysfs_show_atrim(struct device *dev,
560 struct device_attribute *attr, char *buf)
561{
562 int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
563 if (atr < 0)
564 return atr;
565
566 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
567}
568
569static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
570
571static ssize_t
572isl1208_sysfs_show_dtrim(struct device *dev,
573 struct device_attribute *attr, char *buf)
574{
575 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
576 if (dtr < 0)
577 return dtr;
578
579 return sprintf(buf, "%d ppm\n", dtr);
580}
581
582static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
583
584static ssize_t
585isl1208_sysfs_show_usr(struct device *dev,
586 struct device_attribute *attr, char *buf)
587{
588 int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
589 if (usr < 0)
590 return usr;
591
592 return sprintf(buf, "0x%.4x\n", usr);
593}
594
595static ssize_t
596isl1208_sysfs_store_usr(struct device *dev,
597 struct device_attribute *attr,
598 const char *buf, size_t count)
599{
600 int usr = -1;
601
602 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
603 if (sscanf(buf, "%x", &usr) != 1)
604 return -EINVAL;
605 } else {
606 if (sscanf(buf, "%d", &usr) != 1)
607 return -EINVAL;
608 }
609
610 if (usr < 0 || usr > 0xffff)
611 return -EINVAL;
612
613 return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
614}
615
616static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
617 isl1208_sysfs_store_usr);
618
619static struct attribute *isl1208_rtc_attrs[] = {
620 &dev_attr_atrim.attr,
621 &dev_attr_dtrim.attr,
622 &dev_attr_usr.attr,
623 NULL
624};
625
626static const struct attribute_group isl1208_rtc_sysfs_files = {
627 .attrs = isl1208_rtc_attrs,
628};
629
630static int
631isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
632{
633 int rc = 0;
634 struct rtc_device *rtc;
635
636 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
637 return -ENODEV;
638
639 if (isl1208_i2c_validate_client(client) < 0)
640 return -ENODEV;
641
642 dev_info(&client->dev,
643 "chip found, driver version " DRV_VERSION "\n");
644
645 if (client->irq > 0) {
646 rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,
647 isl1208_rtc_interrupt,
648 IRQF_SHARED,
649 isl1208_driver.driver.name,
650 client);
651 if (!rc) {
652 device_init_wakeup(&client->dev, 1);
653 enable_irq_wake(client->irq);
654 } else {
655 dev_err(&client->dev,
656 "Unable to request irq %d, no alarm support\n",
657 client->irq);
658 client->irq = 0;
659 }
660 }
661
662 rtc = devm_rtc_device_register(&client->dev, isl1208_driver.driver.name,
663 &isl1208_rtc_ops,
664 THIS_MODULE);
665 if (IS_ERR(rtc))
666 return PTR_ERR(rtc);
667
668 i2c_set_clientdata(client, rtc);
669
670 rc = isl1208_i2c_get_sr(client);
671 if (rc < 0) {
672 dev_err(&client->dev, "reading status failed\n");
673 return rc;
674 }
675
676 if (rc & ISL1208_REG_SR_RTCF)
677 dev_warn(&client->dev, "rtc power failure detected, "
678 "please set clock.\n");
679
680 rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
681 if (rc)
682 return rc;
683
684 return 0;
685}
686
687static int
688isl1208_remove(struct i2c_client *client)
689{
690 sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
691
692 return 0;
693}
694
695static const struct i2c_device_id isl1208_id[] = {
696 { "isl1208", 0 },
697 { "isl1218", 0 },
698 { }
699};
700MODULE_DEVICE_TABLE(i2c, isl1208_id);
701
702static struct i2c_driver isl1208_driver = {
703 .driver = {
704 .name = "rtc-isl1208",
705 },
706 .probe = isl1208_probe,
707 .remove = isl1208_remove,
708 .id_table = isl1208_id,
709};
710
711module_i2c_driver(isl1208_driver);
712
713MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
714MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
715MODULE_LICENSE("GPL");
716MODULE_VERSION(DRV_VERSION);
717
