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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
63static const struct i2c_device_id rx8025_id[] = {
64 { "rx8025", 0 },
65 { }
66};
67MODULE_DEVICE_TABLE(i2c, rx8025_id);
68
69struct rx8025_data {
70 struct i2c_client *client;
71 struct rtc_device *rtc;
72 u8 ctrl1;
73};
74
75static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
76{
77 return i2c_smbus_read_byte_data(client, number << 4);
78}
79
80static int rx8025_read_regs(const struct i2c_client *client,
81 u8 number, u8 length, u8 *values)
82{
83 int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
84 values);
85 if (ret != length)
86 return ret < 0 ? ret : -EIO;
87
88 return 0;
89}
90
91static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
92 u8 value)
93{
94 return i2c_smbus_write_byte_data(client, number << 4, value);
95}
96
97static s32 rx8025_write_regs(const struct i2c_client *client,
98 u8 number, u8 length, const u8 *values)
99{
100 return i2c_smbus_write_i2c_block_data(client, number << 4,
101 length, values);
102}
103
104static int rx8025_check_validity(struct device *dev)
105{
106 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
107 int ctrl2;
108
109 ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
110 if (ctrl2 < 0)
111 return ctrl2;
112
113 if (ctrl2 & RX8025_BIT_CTRL2_VDET)
114 dev_warn(dev, "power voltage drop detected\n");
115
116 if (ctrl2 & RX8025_BIT_CTRL2_PON) {
117 dev_warn(dev, "power-on reset detected, date is invalid\n");
118 return -EINVAL;
119 }
120
121 if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
122 dev_warn(dev, "crystal stopped, date is invalid\n");
123 return -EINVAL;
124 }
125
126 return 0;
127}
128
129static int rx8025_reset_validity(struct i2c_client *client)
130{
131 int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
132
133 if (ctrl2 < 0)
134 return ctrl2;
135
136 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
137
138 return rx8025_write_reg(client, RX8025_REG_CTRL2,
139 ctrl2 | RX8025_BIT_CTRL2_XST);
140}
141
142static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
143{
144 struct i2c_client *client = dev_id;
145 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
146 struct mutex *lock = &rx8025->rtc->ops_lock;
147 int status;
148
149 mutex_lock(lock);
150 status = rx8025_read_reg(client, RX8025_REG_CTRL2);
151 if (status < 0)
152 goto out;
153
154 if (!(status & RX8025_BIT_CTRL2_XST))
155 dev_warn(&client->dev, "Oscillation stop was detected,"
156 "you may have to readjust the clock\n");
157
158 if (status & RX8025_BIT_CTRL2_CTFG) {
159
160 status &= ~RX8025_BIT_CTRL2_CTFG;
161 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
162 }
163
164 if (status & RX8025_BIT_CTRL2_DAFG) {
165
166 status &= RX8025_BIT_CTRL2_DAFG;
167 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
168 rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
169 goto out;
170 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
171 }
172
173out:
174 mutex_unlock(lock);
175
176 return IRQ_HANDLED;
177}
178
179static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
180{
181 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
182 u8 date[7];
183 int err;
184
185 err = rx8025_check_validity(dev);
186 if (err)
187 return err;
188
189 err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
190 if (err)
191 return err;
192
193 dev_dbg(dev, "%s: read %7ph\n", __func__, date);
194
195 dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
196 dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
197 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
198 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
199 else
200 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
201 + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
202
203 dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
204 dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
205 dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
206
207 dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
208
209 return 0;
210}
211
212static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
213{
214 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
215 u8 date[7];
216 int ret;
217
218 if ((dt->tm_year < 100) || (dt->tm_year > 199))
219 return -EINVAL;
220
221
222
223
224
225 date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
226 date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
227 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
228 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
229 else
230 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
231 | bin2bcd((dt->tm_hour + 11) % 12 + 1);
232
233 date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
234 date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
235 date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
236 date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
237
238 dev_dbg(dev, "%s: write %7ph\n", __func__, date);
239
240 ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
241 if (ret < 0)
242 return ret;
243
244 return rx8025_reset_validity(rx8025->client);
245}
246
247static int rx8025_init_client(struct i2c_client *client)
248{
249 struct rx8025_data *rx8025 = i2c_get_clientdata(client);
250 u8 ctrl[2], ctrl2;
251 int need_clear = 0;
252 int err;
253
254 err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
255 if (err)
256 goto out;
257
258
259 rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
260
261 if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
262 dev_warn(&client->dev, "Alarm was detected\n");
263 need_clear = 1;
264 }
265
266 if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
267 need_clear = 1;
268
269 if (need_clear) {
270 ctrl2 = ctrl[1];
271 ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
272 RX8025_BIT_CTRL2_DAFG);
273
274 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
275 }
276out:
277 return err;
278}
279
280
281static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
282{
283 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
284 struct i2c_client *client = rx8025->client;
285 u8 ald[2];
286 int ctrl2, err;
287
288 if (client->irq <= 0)
289 return -EINVAL;
290
291 err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
292 if (err)
293 return err;
294
295 ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
296 if (ctrl2 < 0)
297 return ctrl2;
298
299 dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
300 __func__, ald[0], ald[1], ctrl2);
301
302
303 t->time.tm_sec = 0;
304 t->time.tm_min = bcd2bin(ald[0] & 0x7f);
305 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
306 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
307 else
308 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
309 + (ald[1] & 0x20 ? 12 : 0);
310
311 dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
312 t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
313 t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
314
315 return err;
316}
317
318static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
319{
320 struct i2c_client *client = to_i2c_client(dev);
321 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
322 u8 ald[2];
323 int err;
324
325 if (client->irq <= 0)
326 return -EINVAL;
327
328
329
330
331
332 if (t->time.tm_sec) {
333 time64_t alarm_time = rtc_tm_to_time64(&t->time);
334
335 alarm_time += 60 - t->time.tm_sec;
336 rtc_time64_to_tm(alarm_time, &t->time);
337 }
338
339 ald[0] = bin2bcd(t->time.tm_min);
340 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
341 ald[1] = bin2bcd(t->time.tm_hour);
342 else
343 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
344 | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
345
346 dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
347
348 if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
349 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
350 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
351 rx8025->ctrl1);
352 if (err)
353 return err;
354 }
355 err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
356 if (err)
357 return err;
358
359 if (t->enabled) {
360 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
361 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
362 rx8025->ctrl1);
363 if (err)
364 return err;
365 }
366
367 return 0;
368}
369
370static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
371{
372 struct rx8025_data *rx8025 = dev_get_drvdata(dev);
373 u8 ctrl1;
374 int err;
375
376 ctrl1 = rx8025->ctrl1;
377 if (enabled)
378 ctrl1 |= RX8025_BIT_CTRL1_DALE;
379 else
380 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
381
382 if (ctrl1 != rx8025->ctrl1) {
383 rx8025->ctrl1 = ctrl1;
384 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
385 rx8025->ctrl1);
386 if (err)
387 return err;
388 }
389 return 0;
390}
391
392static const struct rtc_class_ops rx8025_rtc_ops = {
393 .read_time = rx8025_get_time,
394 .set_time = rx8025_set_time,
395 .read_alarm = rx8025_read_alarm,
396 .set_alarm = rx8025_set_alarm,
397 .alarm_irq_enable = rx8025_alarm_irq_enable,
398};
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416
417static int rx8025_get_clock_adjust(struct device *dev, int *adj)
418{
419 struct i2c_client *client = to_i2c_client(dev);
420 int digoff;
421
422 digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
423 if (digoff < 0)
424 return digoff;
425
426 *adj = digoff >= 64 ? digoff - 128 : digoff;
427 if (*adj > 0)
428 (*adj)--;
429 *adj *= -RX8025_ADJ_RESOLUTION;
430
431 return 0;
432}
433
434static int rx8025_set_clock_adjust(struct device *dev, int adj)
435{
436 struct i2c_client *client = to_i2c_client(dev);
437 u8 digoff;
438 int err;
439
440 adj /= -RX8025_ADJ_RESOLUTION;
441 if (adj > RX8025_ADJ_DATA_MAX)
442 adj = RX8025_ADJ_DATA_MAX;
443 else if (adj < RX8025_ADJ_DATA_MIN)
444 adj = RX8025_ADJ_DATA_MIN;
445 else if (adj > 0)
446 adj++;
447 else if (adj < 0)
448 adj += 128;
449 digoff = adj;
450
451 err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
452 if (err)
453 return err;
454
455 dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
456
457 return 0;
458}
459
460static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
461 struct device_attribute *attr,
462 char *buf)
463{
464 int err, adj;
465
466 err = rx8025_get_clock_adjust(dev, &adj);
467 if (err)
468 return err;
469
470 return sprintf(buf, "%d\n", adj);
471}
472
473static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
474 struct device_attribute *attr,
475 const char *buf, size_t count)
476{
477 int adj, err;
478
479 if (sscanf(buf, "%i", &adj) != 1)
480 return -EINVAL;
481
482 err = rx8025_set_clock_adjust(dev, adj);
483
484 return err ? err : count;
485}
486
487static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
488 rx8025_sysfs_show_clock_adjust,
489 rx8025_sysfs_store_clock_adjust);
490
491static int rx8025_sysfs_register(struct device *dev)
492{
493 return device_create_file(dev, &dev_attr_clock_adjust_ppb);
494}
495
496static void rx8025_sysfs_unregister(struct device *dev)
497{
498 device_remove_file(dev, &dev_attr_clock_adjust_ppb);
499}
500
501static int rx8025_probe(struct i2c_client *client,
502 const struct i2c_device_id *id)
503{
504 struct i2c_adapter *adapter = client->adapter;
505 struct rx8025_data *rx8025;
506 int err = 0;
507
508 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
509 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
510 dev_err(&adapter->dev,
511 "doesn't support required functionality\n");
512 return -EIO;
513 }
514
515 rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
516 if (!rx8025)
517 return -ENOMEM;
518
519 rx8025->client = client;
520 i2c_set_clientdata(client, rx8025);
521
522 err = rx8025_init_client(client);
523 if (err)
524 return err;
525
526 rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
527 &rx8025_rtc_ops, THIS_MODULE);
528 if (IS_ERR(rx8025->rtc)) {
529 dev_err(&client->dev, "unable to register the class device\n");
530 return PTR_ERR(rx8025->rtc);
531 }
532
533 if (client->irq > 0) {
534 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
535 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
536 rx8025_handle_irq,
537 IRQF_ONESHOT,
538 "rx8025", client);
539 if (err) {
540 dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
541 client->irq = 0;
542 }
543 }
544
545 rx8025->rtc->max_user_freq = 1;
546
547
548 rx8025->rtc->uie_unsupported = 1;
549
550 err = rx8025_sysfs_register(&client->dev);
551 return err;
552}
553
554static int rx8025_remove(struct i2c_client *client)
555{
556 rx8025_sysfs_unregister(&client->dev);
557 return 0;
558}
559
560static struct i2c_driver rx8025_driver = {
561 .driver = {
562 .name = "rtc-rx8025",
563 },
564 .probe = rx8025_probe,
565 .remove = rx8025_remove,
566 .id_table = rx8025_id,
567};
568
569module_i2c_driver(rx8025_driver);
570
571MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
572MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
573MODULE_LICENSE("GPL");
574
