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18#include <linux/bcd.h>
19#include <linux/bitops.h>
20#include <linux/i2c.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/rtc.h>
24
25
26#define RX8025_REG_SEC 0x00
27#define RX8025_REG_MIN 0x01
28#define RX8025_REG_HOUR 0x02
29#define RX8025_REG_WDAY 0x03
30#define RX8025_REG_MDAY 0x04
31#define RX8025_REG_MONTH 0x05
32#define RX8025_REG_YEAR 0x06
33#define RX8025_REG_DIGOFF 0x07
34#define RX8025_REG_ALWMIN 0x08
35#define RX8025_REG_ALWHOUR 0x09
36#define RX8025_REG_ALWWDAY 0x0a
37#define RX8025_REG_ALDMIN 0x0b
38#define RX8025_REG_ALDHOUR 0x0c
39
40#define RX8025_REG_CTRL1 0x0e
41#define RX8025_REG_CTRL2 0x0f
42
43#define RX8025_BIT_CTRL1_CT (7 << 0)
44
45#define RX8025_BIT_CTRL1_CT_1HZ 4
46#define RX8025_BIT_CTRL1_TEST BIT(3)
47#define RX8025_BIT_CTRL1_1224 BIT(5)
48#define RX8025_BIT_CTRL1_DALE BIT(6)
49#define RX8025_BIT_CTRL1_WALE BIT(7)
50
51#define RX8025_BIT_CTRL2_DAFG BIT(0)
52#define RX8025_BIT_CTRL2_WAFG BIT(1)
53#define RX8025_BIT_CTRL2_CTFG BIT(2)
54#define RX8025_BIT_CTRL2_PON BIT(4)
55#define RX8025_BIT_CTRL2_XST BIT(5)
56#define RX8025_BIT_CTRL2_VDET BIT(6)
57
58
59#define RX8025_ADJ_RESOLUTION 3050
60#define RX8025_ADJ_DATA_MAX 62
61#define RX8025_ADJ_DATA_MIN -62
62
63enum rx_model {
64 model_rx_unknown,
65 model_rx_8025,
66 model_rx_8035,
67 model_last
68};
69
70static const struct i2c_device_id rx8025_id[] = {
71 { "rx8025", model_rx_8025 },
72 { "rx8035", model_rx_8035 },
73 { }
74};
75MODULE_DEVICE_TABLE(i2c, rx8025_id);
76
77struct rx8025_data {
78 struct rtc_device *rtc;
79 enum rx_model model;
80 u8 ctrl1;
81};
82
83static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
84{
85 return i2c_smbus_read_byte_data(client, number << 4);
86}
87
88static int rx8025_read_regs(const struct i2c_client *client,
89 u8 number, u8 length, u8 *values)
90{
91 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
92 values);
93 if (ret != length)
94 return ret < 0 ? ret : -EIO;
95
96 return 0;
97}
98
99static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
100 u8 value)
101{
102 return i2c_smbus_write_byte_data(client, number << 4, value);
103}
104
105static s32 rx8025_write_regs(const struct i2c_client *client,
106 u8 number, u8 length, const u8 *values)
107{
108 return i2c_smbus_write_i2c_block_data(client, number << 4,
109 length, values);
110}
111
112static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
113{
114 int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
115
116
117
118
119
120 if (model == model_rx_8025)
121 xstp = !xstp;
122
123 return xstp;
124}
125
126static int rx8025_check_validity(struct device *dev)
127{
128 struct i2c_client *client = to_i2c_client(dev);
129 struct rx8025_data *drvdata = dev_get_drvdata(dev);
130 int ctrl2;
131 int xstp;
132
133 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
134 if (ctrl2 < 0)
135 return ctrl2;
136
137 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
138 dev_warn(dev, "power voltage drop detected\n");
139
140 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
141 dev_warn(dev, "power-on reset detected, date is invalid\n");
142 return -EINVAL;
143 }
144
145 xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
146 if (xstp) {
147 dev_warn(dev, "crystal stopped, date is invalid\n");
148 return -EINVAL;
149 }
150
151 return 0;
152}
153
154static int rx8025_reset_validity(struct i2c_client *client)
155{
156 struct rx8025_data *drvdata = i2c_get_clientdata(client);
157 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
158
159 if (ctrl2 < 0)
160 return ctrl2;
161
162 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
163
164 if (drvdata->model == model_rx_8025)
165 ctrl2 |= RX8025_BIT_CTRL2_XST;
166 else
167 ctrl2 &= ~(RX8025_BIT_CTRL2_XST);
168
169 return rx8025_write_reg(client, RX8025_REG_CTRL2,
170 ctrl2);
171}
172
173static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
174{
175 struct i2c_client *client = dev_id;
176 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
177 int status, xstp;
178
179 rtc_lock(rx8025->rtc);
180 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
181 if (status < 0)
182 goto out;
183
184 xstp = rx8025_is_osc_stopped(rx8025->model, status);
185 if (xstp)
186 dev_warn(&client->dev, "Oscillation stop was detected,"
187 "you may have to readjust the clock\n");
188
189 if (status & RX8025_BIT_CTRL2_CTFG) {
190
191 status &= ~RX8025_BIT_CTRL2_CTFG;
192 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
193 }
194
195 if (status & RX8025_BIT_CTRL2_DAFG) {
196
197 status &= RX8025_BIT_CTRL2_DAFG;
198 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
199 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
200 goto out;
201 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
202 }
203
204out:
205 rtc_unlock(rx8025->rtc);
206
207 return IRQ_HANDLED;
208}
209
210static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
211{
212 struct i2c_client *client = to_i2c_client(dev);
213 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
214 u8 date[7];
215 int err;
216
217 err = rx8025_check_validity(dev);
218 if (err)
219 return err;
220
221 err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
222 if (err)
223 return err;
224
225 dev_dbg(dev, "%s: read %7ph\n", __func__, date);
226
227 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
228 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
229 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
230 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
231 else
232 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
233 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
234
235 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
236 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
237 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
238
239 dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
240
241 return 0;
242}
243
244static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
245{
246 struct i2c_client *client = to_i2c_client(dev);
247 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
248 u8 date[7];
249 int ret;
250
251 if ((dt->tm_year < 100) || (dt->tm_year > 199))
252 return -EINVAL;
253
254
255
256
257
258 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
259 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
260 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
261 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
262 else
263 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
264 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
265
266 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
267 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
268 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
269 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
270
271 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
272
273 ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
274 if (ret < 0)
275 return ret;
276
277 return rx8025_reset_validity(client);
278}
279
280static int rx8025_init_client(struct i2c_client *client)
281{
282 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
283 u8 ctrl[2], ctrl2;
284 int need_clear = 0;
285 int err;
286
287 err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
288 if (err)
289 goto out;
290
291
292 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
293
294 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
295 dev_warn(&client->dev, "Alarm was detected\n");
296 need_clear = 1;
297 }
298
299 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
300 need_clear = 1;
301
302 if (need_clear) {
303 ctrl2 = ctrl[1];
304 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
305 RX8025_BIT_CTRL2_DAFG);
306
307 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
308 }
309out:
310 return err;
311}
312
313
314static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
315{
316 struct i2c_client *client = to_i2c_client(dev);
317 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
318 u8 ald[2];
319 int ctrl2, err;
320
321 if (client->irq <= 0)
322 return -EINVAL;
323
324 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
325 if (err)
326 return err;
327
328 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
329 if (ctrl2 < 0)
330 return ctrl2;
331
332 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
333 __func__, ald[0], ald[1], ctrl2);
334
335
336 t->time.tm_sec = 0;
337 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
338 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
339 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
340 else
341 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
342 + (ald[1] & 0x20 ? 12 : 0);
343
344 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
345 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
346 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
347
348 return err;
349}
350
351static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
352{
353 struct i2c_client *client = to_i2c_client(dev);
354 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
355 u8 ald[2];
356 int err;
357
358 if (client->irq <= 0)
359 return -EINVAL;
360
361
362
363
364
365 if (t->time.tm_sec) {
366 time64_t alarm_time = rtc_tm_to_time64(&t->time);
367
368 alarm_time += 60 - t->time.tm_sec;
369 rtc_time64_to_tm(alarm_time, &t->time);
370 }
371
372 ald[0] = bin2bcd(t->time.tm_min);
373 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
374 ald[1] = bin2bcd(t->time.tm_hour);
375 else
376 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
377 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
378
379 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
380
381 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
382 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
383 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
384 rx8025->ctrl1);
385 if (err)
386 return err;
387 }
388 err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
389 if (err)
390 return err;
391
392 if (t->enabled) {
393 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
394 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
395 rx8025->ctrl1);
396 if (err)
397 return err;
398 }
399
400 return 0;
401}
402
403static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
404{
405 struct i2c_client *client = to_i2c_client(dev);
406 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
407 u8 ctrl1;
408 int err;
409
410 ctrl1 = rx8025->ctrl1;
411 if (enabled)
412 ctrl1 |= RX8025_BIT_CTRL1_DALE;
413 else
414 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
415
416 if (ctrl1 != rx8025->ctrl1) {
417 rx8025->ctrl1 = ctrl1;
418 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
419 rx8025->ctrl1);
420 if (err)
421 return err;
422 }
423 return 0;
424}
425
426static const struct rtc_class_ops rx8025_rtc_ops = {
427 .read_time = rx8025_get_time,
428 .set_time = rx8025_set_time,
429 .read_alarm = rx8025_read_alarm,
430 .set_alarm = rx8025_set_alarm,
431 .alarm_irq_enable = rx8025_alarm_irq_enable,
432};
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450
451static int rx8025_get_clock_adjust(struct device *dev, int *adj)
452{
453 struct i2c_client *client = to_i2c_client(dev);
454 int digoff;
455
456 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
457 if (digoff < 0)
458 return digoff;
459
460 *adj = digoff >= 64 ? digoff - 128 : digoff;
461 if (*adj > 0)
462 (*adj)--;
463 *adj *= -RX8025_ADJ_RESOLUTION;
464
465 return 0;
466}
467
468static int rx8025_set_clock_adjust(struct device *dev, int adj)
469{
470 struct i2c_client *client = to_i2c_client(dev);
471 u8 digoff;
472 int err;
473
474 adj /= -RX8025_ADJ_RESOLUTION;
475 if (adj > RX8025_ADJ_DATA_MAX)
476 adj = RX8025_ADJ_DATA_MAX;
477 else if (adj < RX8025_ADJ_DATA_MIN)
478 adj = RX8025_ADJ_DATA_MIN;
479 else if (adj > 0)
480 adj++;
481 else if (adj < 0)
482 adj += 128;
483 digoff = adj;
484
485 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
486 if (err)
487 return err;
488
489 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
490
491 return 0;
492}
493
494static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
495 struct device_attribute *attr,
496 char *buf)
497{
498 int err, adj;
499
500 err = rx8025_get_clock_adjust(dev, &adj);
501 if (err)
502 return err;
503
504 return sprintf(buf, "%d\n", adj);
505}
506
507static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
508 struct device_attribute *attr,
509 const char *buf, size_t count)
510{
511 int adj, err;
512
513 if (sscanf(buf, "%i", &adj) != 1)
514 return -EINVAL;
515
516 err = rx8025_set_clock_adjust(dev, adj);
517
518 return err ? err : count;
519}
520
521static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
522 rx8025_sysfs_show_clock_adjust,
523 rx8025_sysfs_store_clock_adjust);
524
525static int rx8025_sysfs_register(struct device *dev)
526{
527 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
528}
529
530static void rx8025_sysfs_unregister(struct device *dev)
531{
532 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
533}
534
535static int rx8025_probe(struct i2c_client *client,
536 const struct i2c_device_id *id)
537{
538 struct i2c_adapter *adapter = client->adapter;
539 struct rx8025_data *rx8025;
540 int err = 0;
541
542 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
543 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
544 dev_err(&adapter->dev,
545 "doesn't support required functionality\n");
546 return -EIO;
547 }
548
549 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
550 if (!rx8025)
551 return -ENOMEM;
552
553 i2c_set_clientdata(client, rx8025);
554
555 if (id)
556 rx8025->model = id->driver_data;
557
558 err = rx8025_init_client(client);
559 if (err)
560 return err;
561
562 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
563 &rx8025_rtc_ops, THIS_MODULE);
564 if (IS_ERR(rx8025->rtc)) {
565 dev_err(&client->dev, "unable to register the class device\n");
566 return PTR_ERR(rx8025->rtc);
567 }
568
569 if (client->irq > 0) {
570 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
571 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
572 rx8025_handle_irq,
573 IRQF_ONESHOT,
574 "rx8025", client);
575 if (err) {
576 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
577 client->irq = 0;
578 }
579 }
580
581 rx8025->rtc->max_user_freq = 1;
582
583
584 rx8025->rtc->uie_unsupported = 1;
585
586 err = rx8025_sysfs_register(&client->dev);
587 return err;
588}
589
590static int rx8025_remove(struct i2c_client *client)
591{
592 rx8025_sysfs_unregister(&client->dev);
593 return 0;
594}
595
596static struct i2c_driver rx8025_driver = {
597 .driver = {
598 .name = "rtc-rx8025",
599 },
600 .probe = rx8025_probe,
601 .remove = rx8025_remove,
602 .id_table = rx8025_id,
603};
604
605module_i2c_driver(rx8025_driver);
606
607MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
608MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
609MODULE_LICENSE("GPL");
610
