projects/linux·blob master · refs

600 lines · 15.4 KiB

1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2022 Nuvoton Technology Corporation
3
4#include <linux/bcd.h>
5#include <linux/clk-provider.h>
6#include <linux/err.h>
7#include <linux/i2c.h>
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/rtc.h>
11#include <linux/slab.h>
12
13#define NCT3018Y_REG_SC 0x00 /* seconds */
14#define NCT3018Y_REG_SCA 0x01 /* alarm */
15#define NCT3018Y_REG_MN 0x02
16#define NCT3018Y_REG_MNA 0x03 /* alarm */
17#define NCT3018Y_REG_HR 0x04
18#define NCT3018Y_REG_HRA 0x05 /* alarm */
19#define NCT3018Y_REG_DW 0x06
20#define NCT3018Y_REG_DM 0x07
21#define NCT3018Y_REG_MO 0x08
22#define NCT3018Y_REG_YR 0x09
23#define NCT3018Y_REG_CTRL 0x0A /* timer control */
24#define NCT3018Y_REG_ST 0x0B /* status */
25#define NCT3018Y_REG_CLKO 0x0C /* clock out */
26#define NCT3018Y_REG_PART 0x21 /* part info */
27
28#define NCT3018Y_BIT_AF BIT(7)
29#define NCT3018Y_BIT_ST BIT(7)
30#define NCT3018Y_BIT_DM BIT(6)
31#define NCT3018Y_BIT_HF BIT(5)
32#define NCT3018Y_BIT_DSM BIT(4)
33#define NCT3018Y_BIT_AIE BIT(3)
34#define NCT3018Y_BIT_OFIE BIT(2)
35#define NCT3018Y_BIT_CIE BIT(1)
36#define NCT3018Y_BIT_TWO BIT(0)
37
38#define NCT3018Y_REG_BAT_MASK 0x07
39#define NCT3018Y_REG_CLKO_F_MASK 0x03 /* frequenc mask */
40#define NCT3018Y_REG_CLKO_CKE 0x80 /* clock out enabled */
41#define NCT3018Y_REG_PART_NCT3018Y 0x02
42
43struct nct3018y {
44 struct rtc_device *rtc;
45 struct i2c_client *client;
46 int part_num;
47#ifdef CONFIG_COMMON_CLK
48 struct clk_hw clkout_hw;
49#endif
50};
51
52static int nct3018y_set_alarm_mode(struct i2c_client *client, bool on)
53{
54 int err, flags;
55
56 dev_dbg(&client->dev, "%s:on:%d\n", __func__, on);
57
58 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
59 if (flags < 0) {
60 dev_dbg(&client->dev,
61 "Failed to read NCT3018Y_REG_CTRL\n");
62 return flags;
63 }
64
65 if (on)
66 flags |= NCT3018Y_BIT_AIE;
67 else
68 flags &= ~NCT3018Y_BIT_AIE;
69
70 flags |= NCT3018Y_BIT_CIE;
71 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
72 if (err < 0) {
73 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
74 return err;
75 }
76
77 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
78 if (flags < 0) {
79 dev_dbg(&client->dev,
80 "Failed to read NCT3018Y_REG_ST\n");
81 return flags;
82 }
83
84 flags &= ~(NCT3018Y_BIT_AF);
85 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
86 if (err < 0) {
87 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_ST\n");
88 return err;
89 }
90
91 return 0;
92}
93
94static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *alarm_enable,
95 unsigned char *alarm_flag)
96{
97 int flags;
98
99 if (alarm_enable) {
100 dev_dbg(&client->dev, "%s:NCT3018Y_REG_CTRL\n", __func__);
101 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
102 if (flags < 0)
103 return flags;
104 *alarm_enable = flags & NCT3018Y_BIT_AIE;
105 dev_dbg(&client->dev, "%s:alarm_enable:%x\n", __func__, *alarm_enable);
106
107 }
108
109 if (alarm_flag) {
110 dev_dbg(&client->dev, "%s:NCT3018Y_REG_ST\n", __func__);
111 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
112 if (flags < 0)
113 return flags;
114 *alarm_flag = flags & NCT3018Y_BIT_AF;
115 dev_dbg(&client->dev, "%s:alarm_flag:%x\n", __func__, *alarm_flag);
116 }
117
118 return 0;
119}
120
121static irqreturn_t nct3018y_irq(int irq, void *dev_id)
122{
123 struct nct3018y *nct3018y = i2c_get_clientdata(dev_id);
124 struct i2c_client *client = nct3018y->client;
125 int err;
126 unsigned char alarm_flag;
127 unsigned char alarm_enable;
128
129 dev_dbg(&client->dev, "%s:irq:%d\n", __func__, irq);
130 err = nct3018y_get_alarm_mode(nct3018y->client, &alarm_enable, &alarm_flag);
131 if (err)
132 return IRQ_NONE;
133
134 if (alarm_flag) {
135 dev_dbg(&client->dev, "%s:alarm flag:%x\n",
136 __func__, alarm_flag);
137 rtc_update_irq(nct3018y->rtc, 1, RTC_IRQF | RTC_AF);
138 nct3018y_set_alarm_mode(nct3018y->client, 0);
139 dev_dbg(&client->dev, "%s:IRQ_HANDLED\n", __func__);
140 return IRQ_HANDLED;
141 }
142
143 return IRQ_NONE;
144}
145
146/*
147 * In the routines that deal directly with the nct3018y hardware, we use
148 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
149 */
150static int nct3018y_rtc_read_time(struct device *dev, struct rtc_time *tm)
151{
152 struct i2c_client *client = to_i2c_client(dev);
153 unsigned char buf[10];
154 int err;
155
156 err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_ST, 1, buf);
157 if (err < 0)
158 return err;
159
160 if (!buf[0]) {
161 dev_dbg(&client->dev, " voltage <=1.7, date/time is not reliable.\n");
162 return -EINVAL;
163 }
164
165 err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SC, sizeof(buf), buf);
166 if (err < 0)
167 return err;
168
169 tm->tm_sec = bcd2bin(buf[0] & 0x7F);
170 tm->tm_min = bcd2bin(buf[2] & 0x7F);
171 tm->tm_hour = bcd2bin(buf[4] & 0x3F);
172 tm->tm_wday = buf[6] & 0x07;
173 tm->tm_mday = bcd2bin(buf[7] & 0x3F);
174 tm->tm_mon = bcd2bin(buf[8] & 0x1F) - 1;
175 tm->tm_year = bcd2bin(buf[9]) + 100;
176
177 return 0;
178}
179
180static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
181{
182 struct i2c_client *client = to_i2c_client(dev);
183 struct nct3018y *nct3018y = dev_get_drvdata(dev);
184 unsigned char buf[4] = {0};
185 int err, flags;
186 int restore_flags = 0;
187
188 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
189 if (flags < 0) {
190 dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_CTRL.\n");
191 return flags;
192 }
193
194 /* Check and set TWO bit */
195 if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y && !(flags & NCT3018Y_BIT_TWO)) {
196 restore_flags = 1;
197 flags |= NCT3018Y_BIT_TWO;
198 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
199 if (err < 0) {
200 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
201 return err;
202 }
203 }
204
205 buf[0] = bin2bcd(tm->tm_sec);
206 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]);
207 if (err < 0) {
208 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SC\n");
209 return err;
210 }
211
212 buf[0] = bin2bcd(tm->tm_min);
213 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MN, buf[0]);
214 if (err < 0) {
215 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MN\n");
216 return err;
217 }
218
219 buf[0] = bin2bcd(tm->tm_hour);
220 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HR, buf[0]);
221 if (err < 0) {
222 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HR\n");
223 return err;
224 }
225
226 buf[0] = tm->tm_wday & 0x07;
227 buf[1] = bin2bcd(tm->tm_mday);
228 buf[2] = bin2bcd(tm->tm_mon + 1);
229 buf[3] = bin2bcd(tm->tm_year - 100);
230 err = i2c_smbus_write_i2c_block_data(client, NCT3018Y_REG_DW,
231 sizeof(buf), buf);
232 if (err < 0) {
233 dev_dbg(&client->dev, "Unable to write for day and mon and year\n");
234 return -EIO;
235 }
236
237 /* Restore TWO bit */
238 if (restore_flags) {
239 if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y)
240 flags &= ~NCT3018Y_BIT_TWO;
241
242 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
243 if (err < 0) {
244 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
245 return err;
246 }
247 }
248
249 return err;
250}
251
252static int nct3018y_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
253{
254 struct i2c_client *client = to_i2c_client(dev);
255 unsigned char buf[5];
256 int err;
257
258 err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SCA,
259 sizeof(buf), buf);
260 if (err < 0) {
261 dev_dbg(&client->dev, "Unable to read date\n");
262 return -EIO;
263 }
264
265 dev_dbg(&client->dev, "%s: raw data is sec=%02x, min=%02x hr=%02x\n",
266 __func__, buf[0], buf[2], buf[4]);
267
268 tm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
269 tm->time.tm_min = bcd2bin(buf[2] & 0x7F);
270 tm->time.tm_hour = bcd2bin(buf[4] & 0x3F);
271
272 err = nct3018y_get_alarm_mode(client, &tm->enabled, &tm->pending);
273 if (err < 0)
274 return err;
275
276 dev_dbg(&client->dev, "%s:s=%d m=%d, hr=%d, enabled=%d, pending=%d\n",
277 __func__, tm->time.tm_sec, tm->time.tm_min,
278 tm->time.tm_hour, tm->enabled, tm->pending);
279
280 return 0;
281}
282
283static int nct3018y_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
284{
285 struct i2c_client *client = to_i2c_client(dev);
286 int err;
287
288 dev_dbg(dev, "%s, sec=%d, min=%d hour=%d tm->enabled:%d\n",
289 __func__, tm->time.tm_sec, tm->time.tm_min, tm->time.tm_hour,
290 tm->enabled);
291
292 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SCA, bin2bcd(tm->time.tm_sec));
293 if (err < 0) {
294 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SCA\n");
295 return err;
296 }
297
298 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MNA, bin2bcd(tm->time.tm_min));
299 if (err < 0) {
300 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MNA\n");
301 return err;
302 }
303
304 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HRA, bin2bcd(tm->time.tm_hour));
305 if (err < 0) {
306 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HRA\n");
307 return err;
308 }
309
310 return nct3018y_set_alarm_mode(client, tm->enabled);
311}
312
313static int nct3018y_irq_enable(struct device *dev, unsigned int enabled)
314{
315 dev_dbg(dev, "%s: alarm enable=%d\n", __func__, enabled);
316
317 return nct3018y_set_alarm_mode(to_i2c_client(dev), enabled);
318}
319
320static int nct3018y_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
321{
322 struct i2c_client *client = to_i2c_client(dev);
323 int status, flags = 0;
324
325 switch (cmd) {
326 case RTC_VL_READ:
327 status = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
328 if (status < 0)
329 return status;
330
331 if (!(status & NCT3018Y_REG_BAT_MASK))
332 flags |= RTC_VL_DATA_INVALID;
333
334 return put_user(flags, (unsigned int __user *)arg);
335
336 default:
337 return -ENOIOCTLCMD;
338 }
339}
340
341#ifdef CONFIG_COMMON_CLK
342/*
343 * Handling of the clkout
344 */
345
346#define clkout_hw_to_nct3018y(_hw) container_of(_hw, struct nct3018y, clkout_hw)
347
348static const int clkout_rates[] = {
349 32768,
350 1024,
351 32,
352 1,
353};
354
355static unsigned long nct3018y_clkout_recalc_rate(struct clk_hw *hw,
356 unsigned long parent_rate)
357{
358 struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
359 struct i2c_client *client = nct3018y->client;
360 int flags;
361
362 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
363 if (flags < 0)
364 return 0;
365
366 flags &= NCT3018Y_REG_CLKO_F_MASK;
367 return clkout_rates[flags];
368}
369
370static int nct3018y_clkout_determine_rate(struct clk_hw *hw,
371 struct clk_rate_request *req)
372{
373 int i;
374
375 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
376 if (clkout_rates[i] <= req->rate) {
377 req->rate = clkout_rates[i];
378
379 return 0;
380 }
381
382 req->rate = clkout_rates[0];
383
384 return 0;
385}
386
387static int nct3018y_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
388 unsigned long parent_rate)
389{
390 struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
391 struct i2c_client *client = nct3018y->client;
392 int i, flags;
393
394 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
395 if (flags < 0)
396 return flags;
397
398 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
399 if (clkout_rates[i] == rate) {
400 flags &= ~NCT3018Y_REG_CLKO_F_MASK;
401 flags |= i;
402 return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
403 }
404
405 return -EINVAL;
406}
407
408static int nct3018y_clkout_control(struct clk_hw *hw, bool enable)
409{
410 struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
411 struct i2c_client *client = nct3018y->client;
412 int flags;
413
414 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
415 if (flags < 0)
416 return flags;
417
418 if (enable)
419 flags |= NCT3018Y_REG_CLKO_CKE;
420 else
421 flags &= ~NCT3018Y_REG_CLKO_CKE;
422
423 return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
424}
425
426static int nct3018y_clkout_prepare(struct clk_hw *hw)
427{
428 return nct3018y_clkout_control(hw, 1);
429}
430
431static void nct3018y_clkout_unprepare(struct clk_hw *hw)
432{
433 nct3018y_clkout_control(hw, 0);
434}
435
436static int nct3018y_clkout_is_prepared(struct clk_hw *hw)
437{
438 struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
439 struct i2c_client *client = nct3018y->client;
440 int flags;
441
442 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
443 if (flags < 0)
444 return flags;
445
446 return flags & NCT3018Y_REG_CLKO_CKE;
447}
448
449static const struct clk_ops nct3018y_clkout_ops = {
450 .prepare = nct3018y_clkout_prepare,
451 .unprepare = nct3018y_clkout_unprepare,
452 .is_prepared = nct3018y_clkout_is_prepared,
453 .recalc_rate = nct3018y_clkout_recalc_rate,
454 .determine_rate = nct3018y_clkout_determine_rate,
455 .set_rate = nct3018y_clkout_set_rate,
456};
457
458static struct clk *nct3018y_clkout_register_clk(struct nct3018y *nct3018y)
459{
460 struct i2c_client *client = nct3018y->client;
461 struct device_node *node = client->dev.of_node;
462 struct clk_init_data init = {};
463 struct clk *clk;
464
465 init.name = "nct3018y-clkout";
466 init.ops = &nct3018y_clkout_ops;
467 init.flags = 0;
468 init.parent_names = NULL;
469 init.num_parents = 0;
470 nct3018y->clkout_hw.init = &init;
471
472 /* optional override of the clockname */
473 of_property_read_string(node, "clock-output-names", &init.name);
474
475 /* register the clock */
476 clk = devm_clk_register(&client->dev, &nct3018y->clkout_hw);
477
478 if (!IS_ERR(clk))
479 of_clk_add_provider(node, of_clk_src_simple_get, clk);
480
481 return clk;
482}
483#endif
484
485static const struct rtc_class_ops nct3018y_rtc_ops = {
486 .read_time = nct3018y_rtc_read_time,
487 .set_time = nct3018y_rtc_set_time,
488 .read_alarm = nct3018y_rtc_read_alarm,
489 .set_alarm = nct3018y_rtc_set_alarm,
490 .alarm_irq_enable = nct3018y_irq_enable,
491 .ioctl = nct3018y_ioctl,
492};
493
494static int nct3018y_probe(struct i2c_client *client)
495{
496 struct nct3018y *nct3018y;
497 int err, flags;
498
499 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
500 I2C_FUNC_SMBUS_BYTE |
501 I2C_FUNC_SMBUS_BLOCK_DATA))
502 return -ENODEV;
503
504 nct3018y = devm_kzalloc(&client->dev, sizeof(struct nct3018y),
505 GFP_KERNEL);
506 if (!nct3018y)
507 return -ENOMEM;
508
509 i2c_set_clientdata(client, nct3018y);
510 nct3018y->client = client;
511 device_set_wakeup_capable(&client->dev, 1);
512
513 flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
514 if (flags < 0) {
515 dev_dbg(&client->dev, "%s: read error\n", __func__);
516 return flags;
517 } else if (flags & NCT3018Y_BIT_TWO) {
518 dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__);
519 }
520
521 nct3018y->part_num = i2c_smbus_read_byte_data(client, NCT3018Y_REG_PART);
522 if (nct3018y->part_num < 0) {
523 dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_PART.\n");
524 return nct3018y->part_num;
525 } else {
526 nct3018y->part_num &= 0x03; /* Part number is corresponding to bit 0 and 1 */
527 if (nct3018y->part_num == NCT3018Y_REG_PART_NCT3018Y) {
528 flags = NCT3018Y_BIT_HF;
529 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
530 if (err < 0) {
531 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL.\n");
532 return err;
533 }
534 }
535 }
536
537 flags = 0;
538 err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
539 if (err < 0) {
540 dev_dbg(&client->dev, "%s: write error\n", __func__);
541 return err;
542 }
543
544 nct3018y->rtc = devm_rtc_allocate_device(&client->dev);
545 if (IS_ERR(nct3018y->rtc))
546 return PTR_ERR(nct3018y->rtc);
547
548 nct3018y->rtc->ops = &nct3018y_rtc_ops;
549 nct3018y->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
550 nct3018y->rtc->range_max = RTC_TIMESTAMP_END_2099;
551
552 if (client->irq > 0) {
553 err = devm_request_threaded_irq(&client->dev, client->irq,
554 NULL, nct3018y_irq,
555 IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
556 "nct3018y", client);
557 if (err) {
558 dev_dbg(&client->dev, "unable to request IRQ %d\n", client->irq);
559 return err;
560 }
561 } else {
562 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, nct3018y->rtc->features);
563 clear_bit(RTC_FEATURE_ALARM, nct3018y->rtc->features);
564 }
565
566#ifdef CONFIG_COMMON_CLK
567 /* register clk in common clk framework */
568 nct3018y_clkout_register_clk(nct3018y);
569#endif
570
571 return devm_rtc_register_device(nct3018y->rtc);
572}
573
574static const struct i2c_device_id nct3018y_id[] = {
575 { .name = "nct3018y" },
576 { }
577};
578MODULE_DEVICE_TABLE(i2c, nct3018y_id);
579
580static const struct of_device_id nct3018y_of_match[] = {
581 { .compatible = "nuvoton,nct3018y" },
582 {}
583};
584MODULE_DEVICE_TABLE(of, nct3018y_of_match);
585
586static struct i2c_driver nct3018y_driver = {
587 .driver = {
588 .name = "rtc-nct3018y",
589 .of_match_table = nct3018y_of_match,
590 },
591 .probe = nct3018y_probe,
592 .id_table = nct3018y_id,
593};
594
595module_i2c_driver(nct3018y_driver);
596
597MODULE_AUTHOR("Medad CChien <[email protected]>");
598MODULE_AUTHOR("Mia Lin <[email protected]>");
599MODULE_DESCRIPTION("Nuvoton NCT3018Y RTC driver");
600MODULE_LICENSE("GPL");