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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_DISABLE 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
86struct 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
99static 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 -EPERM;
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
124static 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] = 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
171static 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
189static 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 = -1;
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 alm_tm->tm_mon = -1;
217 alm_tm->tm_year = -1;
218
219 ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
220 if (ret < 0)
221 return ret;
222
223 if (ret & HYM8563_CTL2_AIE)
224 alm->enabled = 1;
225
226 return 0;
227}
228
229static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
230{
231 struct i2c_client *client = to_i2c_client(dev);
232 struct rtc_time *alm_tm = &alm->time;
233 u8 buf[4];
234 int ret;
235
236 /*
237 * The alarm has no seconds so deal with it
238 */
239 if (alm_tm->tm_sec) {
240 alm_tm->tm_sec = 0;
241 alm_tm->tm_min++;
242 if (alm_tm->tm_min >= 60) {
243 alm_tm->tm_min = 0;
244 alm_tm->tm_hour++;
245 if (alm_tm->tm_hour >= 24) {
246 alm_tm->tm_hour = 0;
247 alm_tm->tm_mday++;
248 if (alm_tm->tm_mday > 31)
249 alm_tm->tm_mday = 0;
250 }
251 }
252 }
253
254 ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
255 if (ret < 0)
256 return ret;
257
258 ret &= ~HYM8563_CTL2_AIE;
259
260 ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
261 if (ret < 0)
262 return ret;
263
264 buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
265 bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;
266
267 buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
268 bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;
269
270 buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
271 bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;
272
273 buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
274 bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;
275
276 ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
277 if (ret < 0)
278 return ret;
279
280 return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
281}
282
283static const struct rtc_class_ops hym8563_rtc_ops = {
284 .read_time = hym8563_rtc_read_time,
285 .set_time = hym8563_rtc_set_time,
286 .alarm_irq_enable = hym8563_rtc_alarm_irq_enable,
287 .read_alarm = hym8563_rtc_read_alarm,
288 .set_alarm = hym8563_rtc_set_alarm,
289};
290
291/*
292 * Handling of the clkout
293 */
294
295#ifdef CONFIG_COMMON_CLK
296#define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)
297
298static int clkout_rates[] = {
299 32768,
300 1024,
301 32,
302 1,
303};
304
305static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
306 unsigned long parent_rate)
307{
308 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
309 struct i2c_client *client = hym8563->client;
310 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
311
312 if (ret < 0 || ret & HYM8563_CLKOUT_DISABLE)
313 return 0;
314
315 ret &= HYM8563_CLKOUT_MASK;
316 return clkout_rates[ret];
317}
318
319static long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
320 unsigned long *prate)
321{
322 int i;
323
324 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
325 if (clkout_rates[i] <= rate)
326 return clkout_rates[i];
327
328 return 0;
329}
330
331static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
332 unsigned long parent_rate)
333{
334 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
335 struct i2c_client *client = hym8563->client;
336 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
337 int i;
338
339 if (ret < 0)
340 return ret;
341
342 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
343 if (clkout_rates[i] == rate) {
344 ret &= ~HYM8563_CLKOUT_MASK;
345 ret |= i;
346 return i2c_smbus_write_byte_data(client,
347 HYM8563_CLKOUT, ret);
348 }
349
350 return -EINVAL;
351}
352
353static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
354{
355 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
356 struct i2c_client *client = hym8563->client;
357 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
358
359 if (ret < 0)
360 return ret;
361
362 if (enable)
363 ret &= ~HYM8563_CLKOUT_DISABLE;
364 else
365 ret |= HYM8563_CLKOUT_DISABLE;
366
367 return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
368}
369
370static int hym8563_clkout_prepare(struct clk_hw *hw)
371{
372 return hym8563_clkout_control(hw, 1);
373}
374
375static void hym8563_clkout_unprepare(struct clk_hw *hw)
376{
377 hym8563_clkout_control(hw, 0);
378}
379
380static int hym8563_clkout_is_prepared(struct clk_hw *hw)
381{
382 struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
383 struct i2c_client *client = hym8563->client;
384 int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
385
386 if (ret < 0)
387 return ret;
388
389 return !(ret & HYM8563_CLKOUT_DISABLE);
390}
391
392static const struct clk_ops hym8563_clkout_ops = {
393 .prepare = hym8563_clkout_prepare,
394 .unprepare = hym8563_clkout_unprepare,
395 .is_prepared = hym8563_clkout_is_prepared,
396 .recalc_rate = hym8563_clkout_recalc_rate,
397 .round_rate = hym8563_clkout_round_rate,
398 .set_rate = hym8563_clkout_set_rate,
399};
400
401static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
402{
403 struct i2c_client *client = hym8563->client;
404 struct device_node *node = client->dev.of_node;
405 struct clk *clk;
406 struct clk_init_data init;
407 int ret;
408
409 ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
410 HYM8563_CLKOUT_DISABLE);
411 if (ret < 0)
412 return ERR_PTR(ret);
413
414 init.name = "hym8563-clkout";
415 init.ops = &hym8563_clkout_ops;
416 init.flags = CLK_IS_ROOT;
417 init.parent_names = NULL;
418 init.num_parents = 0;
419 hym8563->clkout_hw.init = &init;
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 */
437static 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
463out:
464 mutex_unlock(lock);
465 return IRQ_HANDLED;
466}
467
468static 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
498static 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
514static 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
525static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);
526
527static 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 ret = devm_request_threaded_irq(&client->dev, client->irq,
549 NULL, hym8563_irq,
550 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
551 client->name, hym8563);
552 if (ret < 0) {
553 dev_err(&client->dev, "irq %d request failed, %d\n",
554 client->irq, ret);
555 return ret;
556 }
557
558 /* check state of calendar information */
559 ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
560 if (ret < 0)
561 return ret;
562
563 hym8563->valid = !(ret & HYM8563_SEC_VL);
564 dev_dbg(&client->dev, "rtc information is %s\n",
565 hym8563->valid ? "valid" : "invalid");
566
567 hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
568 &hym8563_rtc_ops, THIS_MODULE);
569 if (IS_ERR(hym8563->rtc))
570 return PTR_ERR(hym8563->rtc);
571
572 /* the hym8563 alarm only supports a minute accuracy */
573 hym8563->rtc->uie_unsupported = 1;
574
575#ifdef CONFIG_COMMON_CLK
576 hym8563_clkout_register_clk(hym8563);
577#endif
578
579 return 0;
580}
581
582static const struct i2c_device_id hym8563_id[] = {
583 { "hym8563", 0 },
584 {},
585};
586MODULE_DEVICE_TABLE(i2c, hym8563_id);
587
588static struct of_device_id hym8563_dt_idtable[] = {
589 { .compatible = "haoyu,hym8563" },
590 {},
591};
592MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);
593
594static struct i2c_driver hym8563_driver = {
595 .driver = {
596 .name = "rtc-hym8563",
597 .owner = THIS_MODULE,
598 .pm = &hym8563_pm_ops,
599 .of_match_table = hym8563_dt_idtable,
600 },
601 .probe = hym8563_probe,
602 .id_table = hym8563_id,
603};
604
605module_i2c_driver(hym8563_driver);
606
607MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
608MODULE_DESCRIPTION("HYM8563 RTC driver");
609MODULE_LICENSE("GPL");