1 /*
2 * Haoyu HYM8563 RTC driver
3 *
4 * Copyright (C) 2013 MundoReader S.L.
5 * Author: Heiko Stuebner <heiko@sntech.de>
6 *
7 * based on rtc-HYM8563
8 * Copyright (C) 2010 ROCKCHIP, Inc.
9 *
10 * This software is licensed under the terms of the GNU General Public
11 * License version 2, as published by the Free Software Foundation, and
12 * may be copied, distributed, and modified under those terms.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20 #include <linux/module.h>
21 #include <linux/clk-provider.h>
22 #include <linux/i2c.h>
23 #include <linux/bcd.h>
24 #include <linux/rtc.h>
25
26 #define HYM8563_CTL1 0x00
27 #define HYM8563_CTL1_TEST BIT(7)
28 #define HYM8563_CTL1_STOP BIT(5)
29 #define HYM8563_CTL1_TESTC BIT(3)
30
31 #define HYM8563_CTL2 0x01
32 #define HYM8563_CTL2_TI_TP BIT(4)
33 #define HYM8563_CTL2_AF BIT(3)
34 #define HYM8563_CTL2_TF BIT(2)
35 #define HYM8563_CTL2_AIE BIT(1)
36 #define HYM8563_CTL2_TIE BIT(0)
37
38 #define HYM8563_SEC 0x02
39 #define HYM8563_SEC_VL BIT(7)
40 #define HYM8563_SEC_MASK 0x7f
41
42 #define HYM8563_MIN 0x03
43 #define HYM8563_MIN_MASK 0x7f
44
45 #define HYM8563_HOUR 0x04
46 #define HYM8563_HOUR_MASK 0x3f
47
48 #define HYM8563_DAY 0x05
49 #define HYM8563_DAY_MASK 0x3f
50
51 #define HYM8563_WEEKDAY 0x06
52 #define HYM8563_WEEKDAY_MASK 0x07
53
54 #define HYM8563_MONTH 0x07
55 #define HYM8563_MONTH_CENTURY BIT(7)
56 #define HYM8563_MONTH_MASK 0x1f
57
58 #define HYM8563_YEAR 0x08
59
60 #define HYM8563_ALM_MIN 0x09
61 #define HYM8563_ALM_HOUR 0x0a
62 #define HYM8563_ALM_DAY 0x0b
63 #define HYM8563_ALM_WEEK 0x0c
64
65 /* Each alarm check can be disabled by setting this bit in the register */
66 #define HYM8563_ALM_BIT_DISABLE BIT(7)
67
68 #define HYM8563_CLKOUT 0x0d
69 #define HYM8563_CLKOUT_ENABLE BIT(7)
70 #define HYM8563_CLKOUT_32768 0
71 #define HYM8563_CLKOUT_1024 1
72 #define HYM8563_CLKOUT_32 2
73 #define HYM8563_CLKOUT_1 3
74 #define HYM8563_CLKOUT_MASK 3
75
76 #define HYM8563_TMR_CTL 0x0e
77 #define HYM8563_TMR_CTL_ENABLE BIT(7)
78 #define HYM8563_TMR_CTL_4096 0
79 #define HYM8563_TMR_CTL_64 1
80 #define HYM8563_TMR_CTL_1 2
81 #define HYM8563_TMR_CTL_1_60 3
82 #define HYM8563_TMR_CTL_MASK 3
83
84 #define HYM8563_TMR_CNT 0x0f
85
86 struct hym8563 {
87 struct i2c_client *client;
88 struct rtc_device *rtc;
89 bool valid;
90 #ifdef CONFIG_COMMON_CLK
91 struct clk_hw clkout_hw;
92 #endif
93 };
94
95 /*
96 * RTC handling
97 */
98
hym8563_rtc_read_time(struct device * dev,struct rtc_time * tm)99 static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
100 {
101 struct i2c_client *client = to_i2c_client(dev);
102 struct hym8563 *hym8563 = i2c_get_clientdata(client);
103 u8 buf[7];
104 int ret;
105
106 if (!hym8563->valid) {
107 dev_warn(&client->dev, "no valid clock/calendar values available\n");
108 return -EINVAL;
109 }
110
111 ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf);
112
113 tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
114 tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
115 tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
116 tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
117 tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
118 tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
119 tm->tm_year = bcd2bin(buf[6]) + 100;
120
121 return 0;
122 }
123
hym8563_rtc_set_time(struct device * dev,struct rtc_time * tm)124 static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
125 {
126 struct i2c_client *client = to_i2c_client(dev);
127 struct hym8563 *hym8563 = i2c_get_clientdata(client);
128 u8 buf[7];
129 int ret;
130
131 /* Years >= 2100 are to far in the future, 19XX is to early */
132 if (tm->tm_year < 100 || tm->tm_year >= 200)
133 return -EINVAL;
134
135 buf[0] = bin2bcd(tm->tm_sec);
136 buf[1] = bin2bcd(tm->tm_min);
137 buf[2] = bin2bcd(tm->tm_hour);
138 buf[3] = bin2bcd(tm->tm_mday);
139 buf[4] = bin2bcd(tm->tm_wday);
140 buf[5] = bin2bcd(tm->tm_mon + 1);
141
142 /*
143 * While the HYM8563 has a century flag in the month register,
144 * it does not seem to carry it over a subsequent write/read.
145 * So we'll limit ourself to 100 years, starting at 2000 for now.
146 */
147 buf[6] = bin2bcd(tm->tm_year - 100);
148
149 /*
150 * CTL1 only contains TEST-mode bits apart from stop,
151 * so no need to read the value first
152 */
153 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
154 HYM8563_CTL1_STOP);
155 if (ret < 0)
156 return ret;
157
158 ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
159 if (ret < 0)
160 return ret;
161
162 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
163 if (ret < 0)
164 return ret;
165
166 hym8563->valid = true;
167
168 return 0;
169 }
170
hym8563_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)171 static int hym8563_rtc_alarm_irq_enable(struct device *dev,
172 unsigned int enabled)
173 {
174 struct i2c_client *client = to_i2c_client(dev);
175 int data;
176
177 data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
178 if (data < 0)
179 return data;
180
181 if (enabled)
182 data |= HYM8563_CTL2_AIE;
183 else
184 data &= ~HYM8563_CTL2_AIE;
185
186 return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
187 };
188
hym8563_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)189 static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
190 {
191 struct i2c_client *client = to_i2c_client(dev);
192 struct rtc_time *alm_tm = &alm->time;
193 u8 buf[4];
194 int ret;
195
196 ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
197 if (ret < 0)
198 return ret;
199
200 /* The alarm only has a minute accuracy */
201 alm_tm->tm_sec = 0;
202
203 alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
204 -1 :
205 bcd2bin(buf[0] & HYM8563_MIN_MASK);
206 alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
207 -1 :
208 bcd2bin(buf[1] & HYM8563_HOUR_MASK);
209 alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
210 -1 :
211 bcd2bin(buf[2] & HYM8563_DAY_MASK);
212 alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
213 -1 :
214 bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);
215
216 ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
217 if (ret < 0)
218 return ret;
219
220 if (ret & HYM8563_CTL2_AIE)
221 alm->enabled = 1;
222
223 return 0;
224 }
225
hym8563_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)226 static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
227 {
228 struct i2c_client *client = to_i2c_client(dev);
229 struct rtc_time *alm_tm = &alm->time;
230 u8 buf[4];
231 int ret;
232
233 /*
234 * The alarm has no seconds so deal with it
235 */
236 if (alm_tm->tm_sec) {
237 alm_tm->tm_sec = 0;
238 alm_tm->tm_min++;
239 if (alm_tm->tm_min >= 60) {
240 alm_tm->tm_min = 0;
241 alm_tm->tm_hour++;
242 if (alm_tm->tm_hour >= 24) {
243 alm_tm->tm_hour = 0;
244 alm_tm->tm_mday++;
245 if (alm_tm->tm_mday > 31)
246 alm_tm->tm_mday = 0;
247 }
248 }
249 }
250
251 ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
252 if (ret < 0)
253 return ret;
254
255 ret &= ~HYM8563_CTL2_AIE;
256
257 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
258 if (ret < 0)
259 return ret;
260
261 buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
262 bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;
263
264 buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
265 bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;
266
267 buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
268 bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;
269
270 buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
271 bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;
272
273 ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
274 if (ret < 0)
275 return ret;
276
277 return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
278 }
279
280 static const struct rtc_class_ops hym8563_rtc_ops = {
281 .read_time = hym8563_rtc_read_time,
282 .set_time = hym8563_rtc_set_time,
283 .alarm_irq_enable = hym8563_rtc_alarm_irq_enable,
284 .read_alarm = hym8563_rtc_read_alarm,
285 .set_alarm = hym8563_rtc_set_alarm,
286 };
287
288 /*
289 * Handling of the clkout
290 */
291
292 #ifdef CONFIG_COMMON_CLK
293 #define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)
294
295 static int clkout_rates[] = {
296 32768,
297 1024,
298 32,
299 1,
300 };
301
hym8563_clkout_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)302 static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
303 unsigned long parent_rate)
304 {
305 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
306 struct i2c_client *client = hym8563->client;
307 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
308
309 if (ret < 0)
310 return 0;
311
312 ret &= HYM8563_CLKOUT_MASK;
313 return clkout_rates[ret];
314 }
315
hym8563_clkout_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)316 static long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
317 unsigned long *prate)
318 {
319 int i;
320
321 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
322 if (clkout_rates[i] <= rate)
323 return clkout_rates[i];
324
325 return 0;
326 }
327
hym8563_clkout_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)328 static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
329 unsigned long parent_rate)
330 {
331 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
332 struct i2c_client *client = hym8563->client;
333 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
334 int i;
335
336 if (ret < 0)
337 return ret;
338
339 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
340 if (clkout_rates[i] == rate) {
341 ret &= ~HYM8563_CLKOUT_MASK;
342 ret |= i;
343 return i2c_smbus_write_byte_data(client,
344 HYM8563_CLKOUT, ret);
345 }
346
347 return -EINVAL;
348 }
349
hym8563_clkout_control(struct clk_hw * hw,bool enable)350 static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
351 {
352 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
353 struct i2c_client *client = hym8563->client;
354 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
355
356 if (ret < 0)
357 return ret;
358
359 if (enable)
360 ret |= HYM8563_CLKOUT_ENABLE;
361 else
362 ret &= ~HYM8563_CLKOUT_ENABLE;
363
364 return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
365 }
366
hym8563_clkout_prepare(struct clk_hw * hw)367 static int hym8563_clkout_prepare(struct clk_hw *hw)
368 {
369 return hym8563_clkout_control(hw, 1);
370 }
371
hym8563_clkout_unprepare(struct clk_hw * hw)372 static void hym8563_clkout_unprepare(struct clk_hw *hw)
373 {
374 hym8563_clkout_control(hw, 0);
375 }
376
hym8563_clkout_is_prepared(struct clk_hw * hw)377 static int hym8563_clkout_is_prepared(struct clk_hw *hw)
378 {
379 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
380 struct i2c_client *client = hym8563->client;
381 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
382
383 if (ret < 0)
384 return ret;
385
386 return !!(ret & HYM8563_CLKOUT_ENABLE);
387 }
388
389 static const struct clk_ops hym8563_clkout_ops = {
390 .prepare = hym8563_clkout_prepare,
391 .unprepare = hym8563_clkout_unprepare,
392 .is_prepared = hym8563_clkout_is_prepared,
393 .recalc_rate = hym8563_clkout_recalc_rate,
394 .round_rate = hym8563_clkout_round_rate,
395 .set_rate = hym8563_clkout_set_rate,
396 };
397
hym8563_clkout_register_clk(struct hym8563 * hym8563)398 static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
399 {
400 struct i2c_client *client = hym8563->client;
401 struct device_node *node = client->dev.of_node;
402 struct clk *clk;
403 struct clk_init_data init;
404 int ret;
405
406 ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
407 0);
408 if (ret < 0)
409 return ERR_PTR(ret);
410
411 init.name = "hym8563-clkout";
412 init.ops = &hym8563_clkout_ops;
413 init.flags = 0;
414 init.parent_names = NULL;
415 init.num_parents = 0;
416 hym8563->clkout_hw.init = &init;
417
418 /* optional override of the clockname */
419 of_property_read_string(node, "clock-output-names", &init.name);
420
421 /* register the clock */
422 clk = clk_register(&client->dev, &hym8563->clkout_hw);
423
424 if (!IS_ERR(clk))
425 of_clk_add_provider(node, of_clk_src_simple_get, clk);
426
427 return clk;
428 }
429 #endif
430
431 /*
432 * The alarm interrupt is implemented as a level-low interrupt in the
433 * hym8563, while the timer interrupt uses a falling edge.
434 * We don't use the timer at all, so the interrupt is requested to
435 * use the level-low trigger.
436 */
hym8563_irq(int irq,void * dev_id)437 static irqreturn_t hym8563_irq(int irq, void *dev_id)
438 {
439 struct hym8563 *hym8563 = (struct hym8563 *)dev_id;
440 struct i2c_client *client = hym8563->client;
441 struct mutex *lock = &hym8563->rtc->ops_lock;
442 int data, ret;
443
444 mutex_lock(lock);
445
446 /* Clear the alarm flag */
447
448 data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
449 if (data < 0) {
450 dev_err(&client->dev, "%s: error reading i2c data %d\n",
451 __func__, data);
452 goto out;
453 }
454
455 data &= ~HYM8563_CTL2_AF;
456
457 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
458 if (ret < 0) {
459 dev_err(&client->dev, "%s: error writing i2c data %d\n",
460 __func__, ret);
461 }
462
463 out:
464 mutex_unlock(lock);
465 return IRQ_HANDLED;
466 }
467
hym8563_init_device(struct i2c_client * client)468 static int hym8563_init_device(struct i2c_client *client)
469 {
470 int ret;
471
472 /* Clear stop flag if present */
473 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
474 if (ret < 0)
475 return ret;
476
477 ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
478 if (ret < 0)
479 return ret;
480
481 /* Disable alarm and timer interrupts */
482 ret &= ~HYM8563_CTL2_AIE;
483 ret &= ~HYM8563_CTL2_TIE;
484
485 /* Clear any pending alarm and timer flags */
486 if (ret & HYM8563_CTL2_AF)
487 ret &= ~HYM8563_CTL2_AF;
488
489 if (ret & HYM8563_CTL2_TF)
490 ret &= ~HYM8563_CTL2_TF;
491
492 ret &= ~HYM8563_CTL2_TI_TP;
493
494 return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
495 }
496
497 #ifdef CONFIG_PM_SLEEP
hym8563_suspend(struct device * dev)498 static int hym8563_suspend(struct device *dev)
499 {
500 struct i2c_client *client = to_i2c_client(dev);
501 int ret;
502
503 if (device_may_wakeup(dev)) {
504 ret = enable_irq_wake(client->irq);
505 if (ret) {
506 dev_err(dev, "enable_irq_wake failed, %d\n", ret);
507 return ret;
508 }
509 }
510
511 return 0;
512 }
513
hym8563_resume(struct device * dev)514 static int hym8563_resume(struct device *dev)
515 {
516 struct i2c_client *client = to_i2c_client(dev);
517
518 if (device_may_wakeup(dev))
519 disable_irq_wake(client->irq);
520
521 return 0;
522 }
523 #endif
524
525 static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);
526
hym8563_probe(struct i2c_client * client,const struct i2c_device_id * id)527 static int hym8563_probe(struct i2c_client *client,
528 const struct i2c_device_id *id)
529 {
530 struct hym8563 *hym8563;
531 int ret;
532
533 hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
534 if (!hym8563)
535 return -ENOMEM;
536
537 hym8563->client = client;
538 i2c_set_clientdata(client, hym8563);
539
540 device_set_wakeup_capable(&client->dev, true);
541
542 ret = hym8563_init_device(client);
543 if (ret) {
544 dev_err(&client->dev, "could not init device, %d\n", ret);
545 return ret;
546 }
547
548 if (client->irq > 0) {
549 ret = devm_request_threaded_irq(&client->dev, client->irq,
550 NULL, hym8563_irq,
551 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
552 client->name, hym8563);
553 if (ret < 0) {
554 dev_err(&client->dev, "irq %d request failed, %d\n",
555 client->irq, ret);
556 return ret;
557 }
558 }
559
560 /* check state of calendar information */
561 ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
562 if (ret < 0)
563 return ret;
564
565 hym8563->valid = !(ret & HYM8563_SEC_VL);
566 dev_dbg(&client->dev, "rtc information is %s\n",
567 hym8563->valid ? "valid" : "invalid");
568
569 hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
570 &hym8563_rtc_ops, THIS_MODULE);
571 if (IS_ERR(hym8563->rtc))
572 return PTR_ERR(hym8563->rtc);
573
574 /* the hym8563 alarm only supports a minute accuracy */
575 hym8563->rtc->uie_unsupported = 1;
576
577 #ifdef CONFIG_COMMON_CLK
578 hym8563_clkout_register_clk(hym8563);
579 #endif
580
581 return 0;
582 }
583
584 static const struct i2c_device_id hym8563_id[] = {
585 { "hym8563", 0 },
586 {},
587 };
588 MODULE_DEVICE_TABLE(i2c, hym8563_id);
589
590 static const struct of_device_id hym8563_dt_idtable[] = {
591 { .compatible = "haoyu,hym8563" },
592 {},
593 };
594 MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);
595
596 static struct i2c_driver hym8563_driver = {
597 .driver = {
598 .name = "rtc-hym8563",
599 .pm = &hym8563_pm_ops,
600 .of_match_table = hym8563_dt_idtable,
601 },
602 .probe = hym8563_probe,
603 .id_table = hym8563_id,
604 };
605
606 module_i2c_driver(hym8563_driver);
607
608 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
609 MODULE_DESCRIPTION("HYM8563 RTC driver");
610 MODULE_LICENSE("GPL");
611