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8#include <linux/module.h>
9#include <linux/rtc.h>
10#include <linux/i2c.h>
11#include <linux/bitrev.h>
12#include <linux/bcd.h>
13#include <linux/slab.h>
14#include <linux/delay.h>
15
16#define S35390A_CMD_STATUS1 0
17#define S35390A_CMD_STATUS2 1
18#define S35390A_CMD_TIME1 2
19#define S35390A_CMD_TIME2 3
20#define S35390A_CMD_INT2_REG1 5
21
22#define S35390A_BYTE_YEAR 0
23#define S35390A_BYTE_MONTH 1
24#define S35390A_BYTE_DAY 2
25#define S35390A_BYTE_WDAY 3
26#define S35390A_BYTE_HOURS 4
27#define S35390A_BYTE_MINS 5
28#define S35390A_BYTE_SECS 6
29
30#define S35390A_ALRM_BYTE_WDAY 0
31#define S35390A_ALRM_BYTE_HOURS 1
32#define S35390A_ALRM_BYTE_MINS 2
33
34
35#define S35390A_FLAG_POC BIT(0)
36#define S35390A_FLAG_BLD BIT(1)
37#define S35390A_FLAG_INT2 BIT(2)
38#define S35390A_FLAG_24H BIT(6)
39#define S35390A_FLAG_RESET BIT(7)
40
41
42#define S35390A_FLAG_TEST BIT(0)
43
44
45#define S35390A_INT2_MODE_MASK 0x0E
46#define S35390A_INT2_MODE_NOINTR 0x00
47#define S35390A_INT2_MODE_ALARM BIT(1)
48#define S35390A_INT2_MODE_PMIN_EDG BIT(2)
49#define S35390A_INT2_MODE_FREQ BIT(3)
50#define S35390A_INT2_MODE_PMIN (BIT(3) | BIT(2))
51
52static const struct i2c_device_id s35390a_id[] = {
53 { "s35390a", 0 },
54 { }
55};
56MODULE_DEVICE_TABLE(i2c, s35390a_id);
57
58static const struct of_device_id s35390a_of_match[] = {
59 { .compatible = "s35390a" },
60 { .compatible = "sii,s35390a" },
61 { }
62};
63MODULE_DEVICE_TABLE(of, s35390a_of_match);
64
65struct s35390a {
66 struct i2c_client *client[8];
67 struct rtc_device *rtc;
68 int twentyfourhour;
69};
70
71static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
72{
73 struct i2c_client *client = s35390a->client[reg];
74 struct i2c_msg msg[] = {
75 {
76 .addr = client->addr,
77 .len = len,
78 .buf = buf
79 },
80 };
81
82 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
83 return -EIO;
84
85 return 0;
86}
87
88static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
89{
90 struct i2c_client *client = s35390a->client[reg];
91 struct i2c_msg msg[] = {
92 {
93 .addr = client->addr,
94 .flags = I2C_M_RD,
95 .len = len,
96 .buf = buf
97 },
98 };
99
100 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
101 return -EIO;
102
103 return 0;
104}
105
106static int s35390a_init(struct s35390a *s35390a)
107{
108 u8 buf;
109 int ret;
110 unsigned initcount = 0;
111
112
113
114
115
116
117
118
119
120initialize:
121 buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
122 ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
123
124 if (ret < 0)
125 return ret;
126
127 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
128 if (ret < 0)
129 return ret;
130
131 if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
132
133 if (initcount < 5) {
134 ++initcount;
135 goto initialize;
136 } else
137 return -EIO;
138 }
139
140 return 1;
141}
142
143
144
145
146
147
148static int s35390a_read_status(struct s35390a *s35390a, char *status1)
149{
150 int ret;
151
152 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
153 if (ret < 0)
154 return ret;
155
156 if (*status1 & S35390A_FLAG_POC) {
157
158
159
160
161 msleep(500);
162 return 1;
163 } else if (*status1 & S35390A_FLAG_BLD)
164 return 1;
165
166
167
168 return 0;
169}
170
171static int s35390a_disable_test_mode(struct s35390a *s35390a)
172{
173 char buf[1];
174
175 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
176 return -EIO;
177
178 if (!(buf[0] & S35390A_FLAG_TEST))
179 return 0;
180
181 buf[0] &= ~S35390A_FLAG_TEST;
182 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
183}
184
185static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
186{
187 if (s35390a->twentyfourhour)
188 return bin2bcd(hour);
189
190 if (hour < 12)
191 return bin2bcd(hour);
192
193 return 0x40 | bin2bcd(hour - 12);
194}
195
196static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
197{
198 unsigned hour;
199
200 if (s35390a->twentyfourhour)
201 return bcd2bin(reg & 0x3f);
202
203 hour = bcd2bin(reg & 0x3f);
204 if (reg & 0x40)
205 hour += 12;
206
207 return hour;
208}
209
210static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
211{
212 struct i2c_client *client = to_i2c_client(dev);
213 struct s35390a *s35390a = i2c_get_clientdata(client);
214 int i, err;
215 char buf[7], status;
216
217 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
218 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
219 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
220 tm->tm_wday);
221
222 if (s35390a_read_status(s35390a, &status) == 1)
223 s35390a_init(s35390a);
224
225 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
226 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
227 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
228 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
229 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
230 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
231 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
232
233
234 for (i = 0; i < 7; ++i)
235 buf[i] = bitrev8(buf[i]);
236
237 err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
238
239 return err;
240}
241
242static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
243{
244 struct i2c_client *client = to_i2c_client(dev);
245 struct s35390a *s35390a = i2c_get_clientdata(client);
246 char buf[7], status;
247 int i, err;
248
249 if (s35390a_read_status(s35390a, &status) == 1)
250 return -EINVAL;
251
252 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
253 if (err < 0)
254 return err;
255
256
257 for (i = 0; i < 7; ++i)
258 buf[i] = bitrev8(buf[i]);
259
260 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
261 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
262 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
263 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
264 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
265 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
266 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
267
268 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
269 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
270 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
271 tm->tm_wday);
272
273 return 0;
274}
275
276static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
277{
278 struct i2c_client *client = to_i2c_client(dev);
279 struct s35390a *s35390a = i2c_get_clientdata(client);
280 char buf[3], sts = 0;
281 int err, i;
282
283 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
284 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
285 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
286 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
287
288 if (alm->time.tm_sec != 0)
289 dev_warn(&client->dev, "Alarms are only supported on a per minute basis!\n");
290
291
292 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
293 if (err < 0)
294 return err;
295
296
297 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
298 if (err < 0)
299 return err;
300
301 if (alm->enabled)
302 sts = S35390A_INT2_MODE_ALARM;
303 else
304 sts = S35390A_INT2_MODE_NOINTR;
305
306
307 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
308 if (err < 0)
309 return err;
310
311 if (alm->time.tm_wday != -1)
312 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
313 else
314 buf[S35390A_ALRM_BYTE_WDAY] = 0;
315
316 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
317 alm->time.tm_hour) | 0x80;
318 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
319
320 if (alm->time.tm_hour >= 12)
321 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
322
323 for (i = 0; i < 3; ++i)
324 buf[i] = bitrev8(buf[i]);
325
326 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
327 sizeof(buf));
328
329 return err;
330}
331
332static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
333{
334 struct i2c_client *client = to_i2c_client(dev);
335 struct s35390a *s35390a = i2c_get_clientdata(client);
336 char buf[3], sts;
337 int i, err;
338
339 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
340 if (err < 0)
341 return err;
342
343 if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
344
345
346
347
348 alm->enabled = 0;
349 return 0;
350 } else {
351 alm->enabled = 1;
352 }
353
354 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
355 if (err < 0)
356 return err;
357
358
359 for (i = 0; i < 3; ++i)
360 buf[i] = bitrev8(buf[i]);
361
362
363
364
365
366 if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
367 alm->time.tm_wday =
368 bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
369
370 if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
371 alm->time.tm_hour =
372 s35390a_reg2hr(s35390a,
373 buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
374
375 if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
376 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
377
378
379 alm->time.tm_sec = 0;
380
381 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
382 __func__, alm->time.tm_min, alm->time.tm_hour,
383 alm->time.tm_wday);
384
385 return 0;
386}
387
388static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
389 unsigned long arg)
390{
391 struct i2c_client *client = to_i2c_client(dev);
392 struct s35390a *s35390a = i2c_get_clientdata(client);
393 char sts;
394 int err;
395
396 switch (cmd) {
397 case RTC_VL_READ:
398
399 err = s35390a_read_status(s35390a, &sts);
400 if (err < 0)
401 return err;
402 if (copy_to_user((void __user *)arg, &err, sizeof(int)))
403 return -EFAULT;
404 break;
405 case RTC_VL_CLR:
406
407 err = s35390a_init(s35390a);
408 if (err < 0)
409 return err;
410 break;
411 default:
412 return -ENOIOCTLCMD;
413 }
414
415 return 0;
416}
417
418static const struct rtc_class_ops s35390a_rtc_ops = {
419 .read_time = s35390a_rtc_read_time,
420 .set_time = s35390a_rtc_set_time,
421 .set_alarm = s35390a_rtc_set_alarm,
422 .read_alarm = s35390a_rtc_read_alarm,
423 .ioctl = s35390a_rtc_ioctl,
424};
425
426static struct i2c_driver s35390a_driver;
427
428static int s35390a_probe(struct i2c_client *client,
429 const struct i2c_device_id *id)
430{
431 int err, err_read;
432 unsigned int i;
433 struct s35390a *s35390a;
434 char buf, status1;
435 struct device *dev = &client->dev;
436
437 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
438 err = -ENODEV;
439 goto exit;
440 }
441
442 s35390a = devm_kzalloc(dev, sizeof(struct s35390a), GFP_KERNEL);
443 if (!s35390a) {
444 err = -ENOMEM;
445 goto exit;
446 }
447
448 s35390a->client[0] = client;
449 i2c_set_clientdata(client, s35390a);
450
451
452 for (i = 1; i < 8; ++i) {
453 s35390a->client[i] = i2c_new_dummy(client->adapter,
454 client->addr + i);
455 if (!s35390a->client[i]) {
456 dev_err(dev, "Address %02x unavailable\n",
457 client->addr + i);
458 err = -EBUSY;
459 goto exit_dummy;
460 }
461 }
462
463 err_read = s35390a_read_status(s35390a, &status1);
464 if (err_read < 0) {
465 err = err_read;
466 dev_err(dev, "error resetting chip\n");
467 goto exit_dummy;
468 }
469
470 if (status1 & S35390A_FLAG_24H)
471 s35390a->twentyfourhour = 1;
472 else
473 s35390a->twentyfourhour = 0;
474
475 if (status1 & S35390A_FLAG_INT2) {
476
477 buf = 0;
478 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
479 if (err < 0) {
480 dev_err(dev, "error disabling alarm");
481 goto exit_dummy;
482 }
483 } else {
484 err = s35390a_disable_test_mode(s35390a);
485 if (err < 0) {
486 dev_err(dev, "error disabling test mode\n");
487 goto exit_dummy;
488 }
489 }
490
491 device_set_wakeup_capable(dev, 1);
492
493 s35390a->rtc = devm_rtc_device_register(dev, s35390a_driver.driver.name,
494 &s35390a_rtc_ops, THIS_MODULE);
495
496 if (IS_ERR(s35390a->rtc)) {
497 err = PTR_ERR(s35390a->rtc);
498 goto exit_dummy;
499 }
500
501
502 s35390a->rtc->uie_unsupported = 1;
503
504 if (status1 & S35390A_FLAG_INT2)
505 rtc_update_irq(s35390a->rtc, 1, RTC_AF);
506
507 return 0;
508
509exit_dummy:
510 for (i = 1; i < 8; ++i)
511 if (s35390a->client[i])
512 i2c_unregister_device(s35390a->client[i]);
513
514exit:
515 return err;
516}
517
518static int s35390a_remove(struct i2c_client *client)
519{
520 unsigned int i;
521 struct s35390a *s35390a = i2c_get_clientdata(client);
522
523 for (i = 1; i < 8; ++i)
524 if (s35390a->client[i])
525 i2c_unregister_device(s35390a->client[i]);
526
527 return 0;
528}
529
530static struct i2c_driver s35390a_driver = {
531 .driver = {
532 .name = "rtc-s35390a",
533 .of_match_table = of_match_ptr(s35390a_of_match),
534 },
535 .probe = s35390a_probe,
536 .remove = s35390a_remove,
537 .id_table = s35390a_id,
538};
539
540module_i2c_driver(s35390a_driver);
541
542MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
543MODULE_DESCRIPTION("S35390A RTC driver");
544MODULE_LICENSE("GPL");
545