1 /*
2 * Driver for the Epson RTC module RX-8010 SJ
3 *
4 * Copyright(C) Timesys Corporation 2015
5 * Copyright(C) General Electric Company 2015
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12
13 #include <linux/bcd.h>
14 #include <linux/bitops.h>
15 #include <linux/i2c.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/rtc.h>
19
20 #define RX8010_SEC 0x10
21 #define RX8010_MIN 0x11
22 #define RX8010_HOUR 0x12
23 #define RX8010_WDAY 0x13
24 #define RX8010_MDAY 0x14
25 #define RX8010_MONTH 0x15
26 #define RX8010_YEAR 0x16
27 #define RX8010_RESV17 0x17
28 #define RX8010_ALMIN 0x18
29 #define RX8010_ALHOUR 0x19
30 #define RX8010_ALWDAY 0x1A
31 #define RX8010_TCOUNT0 0x1B
32 #define RX8010_TCOUNT1 0x1C
33 #define RX8010_EXT 0x1D
34 #define RX8010_FLAG 0x1E
35 #define RX8010_CTRL 0x1F
36 /* 0x20 to 0x2F are user registers */
37 #define RX8010_RESV30 0x30
38 #define RX8010_RESV31 0x31
39 #define RX8010_IRQ 0x32
40
41 #define RX8010_EXT_WADA BIT(3)
42
43 #define RX8010_FLAG_VLF BIT(1)
44 #define RX8010_FLAG_AF BIT(3)
45 #define RX8010_FLAG_TF BIT(4)
46 #define RX8010_FLAG_UF BIT(5)
47
48 #define RX8010_CTRL_AIE BIT(3)
49 #define RX8010_CTRL_UIE BIT(5)
50 #define RX8010_CTRL_STOP BIT(6)
51 #define RX8010_CTRL_TEST BIT(7)
52
53 #define RX8010_ALARM_AE BIT(7)
54
55 static const struct i2c_device_id rx8010_id[] = {
56 { "rx8010", 0 },
57 { }
58 };
59 MODULE_DEVICE_TABLE(i2c, rx8010_id);
60
61 static const struct of_device_id rx8010_of_match[] = {
62 { .compatible = "epson,rx8010" },
63 { }
64 };
65 MODULE_DEVICE_TABLE(of, rx8010_of_match);
66
67 struct rx8010_data {
68 struct i2c_client *client;
69 struct rtc_device *rtc;
70 u8 ctrlreg;
71 };
72
rx8010_irq_1_handler(int irq,void * dev_id)73 static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
74 {
75 struct i2c_client *client = dev_id;
76 struct rx8010_data *rx8010 = i2c_get_clientdata(client);
77 int flagreg;
78
79 mutex_lock(&rx8010->rtc->ops_lock);
80
81 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
82
83 if (flagreg <= 0) {
84 mutex_unlock(&rx8010->rtc->ops_lock);
85 return IRQ_NONE;
86 }
87
88 if (flagreg & RX8010_FLAG_VLF)
89 dev_warn(&client->dev, "Frequency stop detected\n");
90
91 if (flagreg & RX8010_FLAG_TF) {
92 flagreg &= ~RX8010_FLAG_TF;
93 rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
94 }
95
96 if (flagreg & RX8010_FLAG_AF) {
97 flagreg &= ~RX8010_FLAG_AF;
98 rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
99 }
100
101 if (flagreg & RX8010_FLAG_UF) {
102 flagreg &= ~RX8010_FLAG_UF;
103 rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
104 }
105
106 i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
107
108 mutex_unlock(&rx8010->rtc->ops_lock);
109 return IRQ_HANDLED;
110 }
111
rx8010_get_time(struct device * dev,struct rtc_time * dt)112 static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
113 {
114 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
115 u8 date[7];
116 int flagreg;
117 int err;
118
119 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
120 if (flagreg < 0)
121 return flagreg;
122
123 if (flagreg & RX8010_FLAG_VLF) {
124 dev_warn(dev, "Frequency stop detected\n");
125 return -EINVAL;
126 }
127
128 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
129 7, date);
130 if (err != 7)
131 return err < 0 ? err : -EIO;
132
133 dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
134 dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
135 dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
136 dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
137 dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
138 dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
139 dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
140
141 return 0;
142 }
143
rx8010_set_time(struct device * dev,struct rtc_time * dt)144 static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
145 {
146 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
147 u8 date[7];
148 int ctrl, flagreg;
149 int ret;
150
151 if ((dt->tm_year < 100) || (dt->tm_year > 199))
152 return -EINVAL;
153
154 /* set STOP bit before changing clock/calendar */
155 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
156 if (ctrl < 0)
157 return ctrl;
158 rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
159 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
160 rx8010->ctrlreg);
161 if (ret < 0)
162 return ret;
163
164 date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
165 date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
166 date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
167 date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
168 date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
169 date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
170 date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
171
172 ret = i2c_smbus_write_i2c_block_data(rx8010->client,
173 RX8010_SEC, 7, date);
174 if (ret < 0)
175 return ret;
176
177 /* clear STOP bit after changing clock/calendar */
178 ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
179 if (ctrl < 0)
180 return ctrl;
181 rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
182 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
183 rx8010->ctrlreg);
184 if (ret < 0)
185 return ret;
186
187 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
188 if (flagreg < 0) {
189 return flagreg;
190 }
191
192 if (flagreg & RX8010_FLAG_VLF)
193 ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
194 flagreg & ~RX8010_FLAG_VLF);
195
196 return 0;
197 }
198
rx8010_init_client(struct i2c_client * client)199 static int rx8010_init_client(struct i2c_client *client)
200 {
201 struct rx8010_data *rx8010 = i2c_get_clientdata(client);
202 u8 ctrl[2];
203 int need_clear = 0, err = 0;
204
205 /* Initialize reserved registers as specified in datasheet */
206 err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
207 if (err < 0)
208 return err;
209
210 err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
211 if (err < 0)
212 return err;
213
214 err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
215 if (err < 0)
216 return err;
217
218 err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
219 if (err < 0)
220 return err;
221
222 err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
223 2, ctrl);
224 if (err != 2)
225 return err < 0 ? err : -EIO;
226
227 if (ctrl[0] & RX8010_FLAG_VLF)
228 dev_warn(&client->dev, "Frequency stop was detected\n");
229
230 if (ctrl[0] & RX8010_FLAG_AF) {
231 dev_warn(&client->dev, "Alarm was detected\n");
232 need_clear = 1;
233 }
234
235 if (ctrl[0] & RX8010_FLAG_TF)
236 need_clear = 1;
237
238 if (ctrl[0] & RX8010_FLAG_UF)
239 need_clear = 1;
240
241 if (need_clear) {
242 ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
243 err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
244 if (err < 0)
245 return err;
246 }
247
248 rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
249
250 return 0;
251 }
252
rx8010_read_alarm(struct device * dev,struct rtc_wkalrm * t)253 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
254 {
255 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
256 struct i2c_client *client = rx8010->client;
257 u8 alarmvals[3];
258 int flagreg;
259 int err;
260
261 err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
262 if (err != 3)
263 return err < 0 ? err : -EIO;
264
265 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
266 if (flagreg < 0)
267 return flagreg;
268
269 t->time.tm_sec = 0;
270 t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
271 t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
272
273 if (!(alarmvals[2] & RX8010_ALARM_AE))
274 t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
275
276 t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
277 t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
278
279 return 0;
280 }
281
rx8010_set_alarm(struct device * dev,struct rtc_wkalrm * t)282 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
283 {
284 struct i2c_client *client = to_i2c_client(dev);
285 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
286 u8 alarmvals[3];
287 int extreg, flagreg;
288 int err;
289
290 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
291 if (flagreg < 0) {
292 return flagreg;
293 }
294
295 if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
296 rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
297 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
298 rx8010->ctrlreg);
299 if (err < 0) {
300 return err;
301 }
302 }
303
304 flagreg &= ~RX8010_FLAG_AF;
305 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
306 if (err < 0)
307 return err;
308
309 alarmvals[0] = bin2bcd(t->time.tm_min);
310 alarmvals[1] = bin2bcd(t->time.tm_hour);
311 alarmvals[2] = bin2bcd(t->time.tm_mday);
312
313 err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
314 2, alarmvals);
315 if (err < 0)
316 return err;
317
318 extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
319 if (extreg < 0)
320 return extreg;
321
322 extreg |= RX8010_EXT_WADA;
323 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
324 if (err < 0)
325 return err;
326
327 if (alarmvals[2] == 0)
328 alarmvals[2] |= RX8010_ALARM_AE;
329
330 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
331 alarmvals[2]);
332 if (err < 0)
333 return err;
334
335 if (t->enabled) {
336 if (rx8010->rtc->uie_rtctimer.enabled)
337 rx8010->ctrlreg |= RX8010_CTRL_UIE;
338 if (rx8010->rtc->aie_timer.enabled)
339 rx8010->ctrlreg |=
340 (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
341
342 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
343 rx8010->ctrlreg);
344 if (err < 0)
345 return err;
346 }
347
348 return 0;
349 }
350
rx8010_alarm_irq_enable(struct device * dev,unsigned int enabled)351 static int rx8010_alarm_irq_enable(struct device *dev,
352 unsigned int enabled)
353 {
354 struct i2c_client *client = to_i2c_client(dev);
355 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
356 int flagreg;
357 u8 ctrl;
358 int err;
359
360 ctrl = rx8010->ctrlreg;
361
362 if (enabled) {
363 if (rx8010->rtc->uie_rtctimer.enabled)
364 ctrl |= RX8010_CTRL_UIE;
365 if (rx8010->rtc->aie_timer.enabled)
366 ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
367 } else {
368 if (!rx8010->rtc->uie_rtctimer.enabled)
369 ctrl &= ~RX8010_CTRL_UIE;
370 if (!rx8010->rtc->aie_timer.enabled)
371 ctrl &= ~RX8010_CTRL_AIE;
372 }
373
374 flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
375 if (flagreg < 0)
376 return flagreg;
377
378 flagreg &= ~RX8010_FLAG_AF;
379 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
380 if (err < 0)
381 return err;
382
383 if (ctrl != rx8010->ctrlreg) {
384 rx8010->ctrlreg = ctrl;
385 err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
386 rx8010->ctrlreg);
387 if (err < 0)
388 return err;
389 }
390
391 return 0;
392 }
393
rx8010_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)394 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
395 {
396 struct i2c_client *client = to_i2c_client(dev);
397 struct rx8010_data *rx8010 = dev_get_drvdata(dev);
398 int ret, tmp;
399 int flagreg;
400
401 switch (cmd) {
402 case RTC_VL_READ:
403 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
404 if (flagreg < 0)
405 return flagreg;
406
407 tmp = !!(flagreg & RX8010_FLAG_VLF);
408 if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
409 return -EFAULT;
410
411 return 0;
412
413 case RTC_VL_CLR:
414 flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
415 if (flagreg < 0) {
416 return flagreg;
417 }
418
419 flagreg &= ~RX8010_FLAG_VLF;
420 ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
421 if (ret < 0)
422 return ret;
423
424 return 0;
425
426 default:
427 return -ENOIOCTLCMD;
428 }
429 }
430
431 static const struct rtc_class_ops rx8010_rtc_ops_default = {
432 .read_time = rx8010_get_time,
433 .set_time = rx8010_set_time,
434 .ioctl = rx8010_ioctl,
435 };
436
437 static const struct rtc_class_ops rx8010_rtc_ops_alarm = {
438 .read_time = rx8010_get_time,
439 .set_time = rx8010_set_time,
440 .ioctl = rx8010_ioctl,
441 .read_alarm = rx8010_read_alarm,
442 .set_alarm = rx8010_set_alarm,
443 .alarm_irq_enable = rx8010_alarm_irq_enable,
444 };
445
rx8010_probe(struct i2c_client * client,const struct i2c_device_id * id)446 static int rx8010_probe(struct i2c_client *client,
447 const struct i2c_device_id *id)
448 {
449 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
450 const struct rtc_class_ops *rtc_ops;
451 struct rx8010_data *rx8010;
452 int err = 0;
453
454 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
455 | I2C_FUNC_SMBUS_I2C_BLOCK)) {
456 dev_err(&adapter->dev, "doesn't support required functionality\n");
457 return -EIO;
458 }
459
460 rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
461 GFP_KERNEL);
462 if (!rx8010)
463 return -ENOMEM;
464
465 rx8010->client = client;
466 i2c_set_clientdata(client, rx8010);
467
468 err = rx8010_init_client(client);
469 if (err)
470 return err;
471
472 if (client->irq > 0) {
473 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
474 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
475 rx8010_irq_1_handler,
476 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
477 "rx8010", client);
478
479 if (err) {
480 dev_err(&client->dev, "unable to request IRQ\n");
481 return err;
482 }
483
484 rtc_ops = &rx8010_rtc_ops_alarm;
485 } else {
486 rtc_ops = &rx8010_rtc_ops_default;
487 }
488
489 rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
490 rtc_ops, THIS_MODULE);
491
492 if (IS_ERR(rx8010->rtc)) {
493 dev_err(&client->dev, "unable to register the class device\n");
494 return PTR_ERR(rx8010->rtc);
495 }
496
497 rx8010->rtc->max_user_freq = 1;
498
499 return err;
500 }
501
502 static struct i2c_driver rx8010_driver = {
503 .driver = {
504 .name = "rtc-rx8010",
505 .of_match_table = of_match_ptr(rx8010_of_match),
506 },
507 .probe = rx8010_probe,
508 .id_table = rx8010_id,
509 };
510
511 module_i2c_driver(rx8010_driver);
512
513 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
514 MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
515 MODULE_LICENSE("GPL v2");
516