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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
252
253
254
255 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
256 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
257 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
258 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
259 else
260 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
261 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
262
263 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
264 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
265 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
266 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
267
268 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
269
270 ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
271 if (ret < 0)
272 return ret;
273
274 return rx8025_reset_validity(client);
275}
276
277static int rx8025_init_client(struct i2c_client *client)
278{
279 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
280 u8 ctrl[2], ctrl2;
281 int need_clear = 0;
282 int err;
283
284 err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
285 if (err)
286 goto out;
287
288
289 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
290
291 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
292 dev_warn(&client->dev, "Alarm was detected\n");
293 need_clear = 1;
294 }
295
296 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
297 need_clear = 1;
298
299 if (need_clear) {
300 ctrl2 = ctrl[1];
301 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
302 RX8025_BIT_CTRL2_DAFG);
303
304 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
305 }
306out:
307 return err;
308}
309
310
311static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
312{
313 struct i2c_client *client = to_i2c_client(dev);
314 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
315 u8 ald[2];
316 int ctrl2, err;
317
318 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
319 if (err)
320 return err;
321
322 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
323 if (ctrl2 < 0)
324 return ctrl2;
325
326 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
327 __func__, ald[0], ald[1], ctrl2);
328
329
330 t->time.tm_sec = 0;
331 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
332 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
333 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
334 else
335 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
336 + (ald[1] & 0x20 ? 12 : 0);
337
338 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
339 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
340 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
341
342 return err;
343}
344
345static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
346{
347 struct i2c_client *client = to_i2c_client(dev);
348 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
349 u8 ald[2];
350 int err;
351
352 ald[0] = bin2bcd(t->time.tm_min);
353 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
354 ald[1] = bin2bcd(t->time.tm_hour);
355 else
356 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
357 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
358
359 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
360
361 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
362 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
363 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
364 rx8025->ctrl1);
365 if (err)
366 return err;
367 }
368 err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
369 if (err)
370 return err;
371
372 if (t->enabled) {
373 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
374 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
375 rx8025->ctrl1);
376 if (err)
377 return err;
378 }
379
380 return 0;
381}
382
383static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
384{
385 struct i2c_client *client = to_i2c_client(dev);
386 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
387 u8 ctrl1;
388 int err;
389
390 ctrl1 = rx8025->ctrl1;
391 if (enabled)
392 ctrl1 |= RX8025_BIT_CTRL1_DALE;
393 else
394 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
395
396 if (ctrl1 != rx8025->ctrl1) {
397 rx8025->ctrl1 = ctrl1;
398 err = rx8025_write_reg(client, RX8025_REG_CTRL1,
399 rx8025->ctrl1);
400 if (err)
401 return err;
402 }
403 return 0;
404}
405
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410
411
412
413
414
415
416
417
418static int rx8025_read_offset(struct device *dev, long *offset)
419{
420 struct i2c_client *client = to_i2c_client(dev);
421 int digoff;
422
423 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
424 if (digoff < 0)
425 return digoff;
426
427 *offset = digoff >= 64 ? digoff - 128 : digoff;
428 if (*offset > 0)
429 (*offset)--;
430 *offset *= RX8025_ADJ_RESOLUTION;
431
432 return 0;
433}
434
435static int rx8025_set_offset(struct device *dev, long offset)
436{
437 struct i2c_client *client = to_i2c_client(dev);
438 u8 digoff;
439
440 offset /= RX8025_ADJ_RESOLUTION;
441 if (offset > RX8025_ADJ_DATA_MAX)
442 offset = RX8025_ADJ_DATA_MAX;
443 else if (offset < RX8025_ADJ_DATA_MIN)
444 offset = RX8025_ADJ_DATA_MIN;
445 else if (offset > 0)
446 offset++;
447 else if (offset < 0)
448 offset += 128;
449 digoff = offset;
450
451 return rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
452}
453
454static const struct rtc_class_ops rx8025_rtc_ops = {
455 .read_time = rx8025_get_time,
456 .set_time = rx8025_set_time,
457 .read_alarm = rx8025_read_alarm,
458 .set_alarm = rx8025_set_alarm,
459 .alarm_irq_enable = rx8025_alarm_irq_enable,
460 .read_offset = rx8025_read_offset,
461 .set_offset = rx8025_set_offset,
462};
463
464static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
465 struct device_attribute *attr,
466 char *buf)
467{
468 long adj;
469 int err;
470
471 dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
472 err = rx8025_read_offset(dev, &adj);
473 if (err)
474 return err;
475
476 return sprintf(buf, "%ld\n", -adj);
477}
478
479static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
480 struct device_attribute *attr,
481 const char *buf, size_t count)
482{
483 long adj;
484 int err;
485
486 dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
487 if (kstrtol(buf, 10, &adj) != 0)
488 return -EINVAL;
489
490 err = rx8025_set_offset(dev, -adj);
491
492 return err ? err : count;
493}
494
495static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
496 rx8025_sysfs_show_clock_adjust,
497 rx8025_sysfs_store_clock_adjust);
498
499static struct attribute *rx8025_attrs[] = {
500 &dev_attr_clock_adjust_ppb.attr,
501 NULL
502};
503
504static const struct attribute_group rx8025_attr_group = {
505 .attrs = rx8025_attrs,
506};
507
508static int rx8025_probe(struct i2c_client *client,
509 const struct i2c_device_id *id)
510{
511 struct i2c_adapter *adapter = client->adapter;
512 struct rx8025_data *rx8025;
513 int err = 0;
514
515 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
516 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
517 dev_err(&adapter->dev,
518 "doesn't support required functionality\n");
519 return -EIO;
520 }
521
522 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
523 if (!rx8025)
524 return -ENOMEM;
525
526 i2c_set_clientdata(client, rx8025);
527
528 if (id)
529 rx8025->model = id->driver_data;
530
531 err = rx8025_init_client(client);
532 if (err)
533 return err;
534
535 rx8025->rtc = devm_rtc_allocate_device(&client->dev);
536 if (IS_ERR(rx8025->rtc))
537 return PTR_ERR(rx8025->rtc);
538
539 rx8025->rtc->ops = &rx8025_rtc_ops;
540 rx8025->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
541 rx8025->rtc->range_max = RTC_TIMESTAMP_END_2099;
542
543 if (client->irq > 0) {
544 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
545 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
546 rx8025_handle_irq,
547 IRQF_ONESHOT,
548 "rx8025", client);
549 if (err)
550 clear_bit(RTC_FEATURE_ALARM, rx8025->rtc->features);
551 }
552
553 rx8025->rtc->max_user_freq = 1;
554
555 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rx8025->rtc->features);
556 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rx8025->rtc->features);
557
558 err = rtc_add_group(rx8025->rtc, &rx8025_attr_group);
559 if (err)
560 return err;
561
562 return devm_rtc_register_device(rx8025->rtc);
563}
564
565static struct i2c_driver rx8025_driver = {
566 .driver = {
567 .name = "rtc-rx8025",
568 },
569 .probe = rx8025_probe,
570 .id_table = rx8025_id,
571};
572
573module_i2c_driver(rx8025_driver);
574
575MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
576MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
577MODULE_LICENSE("GPL");
578
